diff --git a/src/bin/Jamfile b/src/bin/Jamfile
index bfb3d34b38..dce6e79837 100644
--- a/src/bin/Jamfile
+++ b/src/bin/Jamfile
@@ -155,6 +155,7 @@ SubInclude HAIKU_TOP src bin ideinfo ;
 SubInclude HAIKU_TOP src bin keymap ;
 SubInclude HAIKU_TOP src bin less ;
 SubInclude HAIKU_TOP src bin listdev ;
+SubInclude HAIKU_TOP src bin m4 ;
 SubInclude HAIKU_TOP src bin make ;
 SubInclude HAIKU_TOP src bin makebootable ;
 #SubInclude HAIKU_TOP src bin makeudfimage ;
diff --git a/src/bin/m4/COPYING b/src/bin/m4/COPYING
new file mode 100644
index 0000000000..d511905c16
--- /dev/null
+++ b/src/bin/m4/COPYING
@@ -0,0 +1,339 @@
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
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+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
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+
+If distribution of executable or object code is made by offering
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+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	    How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.
diff --git a/src/bin/m4/Jamfile b/src/bin/m4/Jamfile
new file mode 100644
index 0000000000..be30672b1a
--- /dev/null
+++ b/src/bin/m4/Jamfile
@@ -0,0 +1,5 @@
+SubDir HAIKU_TOP src bin m4 ;
+
+SubInclude HAIKU_TOP src bin m4 lib ;
+SubInclude HAIKU_TOP src bin m4 src ;
+
diff --git a/src/bin/m4/doc/Makefile.am b/src/bin/m4/doc/Makefile.am
new file mode 100644
index 0000000000..9e2dacf560
--- /dev/null
+++ b/src/bin/m4/doc/Makefile.am
@@ -0,0 +1,43 @@
+## This file is part of GNU M4.
+##
+## Copyright (C) 2006 Free Software Foundation, Inc.
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; see the file COPYING.  If not, write to
+## the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+## Boston, MA 02110-1301, USA.
+##
+## This file written by Eric Blake <ebb9@byu.net>
+
+info_TEXINFOS = m4.texinfo
+m4_TEXINFOS = fdl.texi
+man_MANS = m4.1
+EXTRA_DIST = $(man_MANS) gendocs_template
+MAINTAINERCLEANFILES = $(man_MANS) gendocs_template
+SUFFIXES = .1
+
+# Depend on configure.ac for version, m4.c for usage text.  Do not depend on
+# built m4 executable, since not everyone has help2man or perl.
+# Build the man page once in the srcdir, rather than in every VPATH build
+# dir, to match how automake builds info pages.  This is safe for 'make
+# distcheck' since it is distributed pre-built.
+$(srcdir)/m4.1: $(top_srcdir)/configure.ac $(top_srcdir)/src/m4.c
+	@if test -x ../src/m4$(EXEEXT) ; then \
+	  echo "Updating man page m4.1" ; \
+	  $(SHELL) $(top_srcdir)/missing --run \
+	    help2man --name="macro processor" --source=FSF \
+	      --info-page=m4 --output=$@ ../src/m4$(EXEEXT) ; \
+	else \
+	  echo "WARNING: The \`man' page \`$@' cannot be updated yet."; \
+	  echo "         Retry once the program executable is ready."; \
+	fi
diff --git a/src/bin/m4/doc/Makefile.in b/src/bin/m4/doc/Makefile.in
new file mode 100644
index 0000000000..69183b5788
--- /dev/null
+++ b/src/bin/m4/doc/Makefile.in
@@ -0,0 +1,708 @@
+# Makefile.in generated by automake 1.10 from Makefile.am.
+# @configure_input@
+
+# Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
+# 2003, 2004, 2005, 2006  Free Software Foundation, Inc.
+# This Makefile.in is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+@SET_MAKE@
+VPATH = @srcdir@
+pkgdatadir = $(datadir)/@PACKAGE@
+pkglibdir = $(libdir)/@PACKAGE@
+pkgincludedir = $(includedir)/@PACKAGE@
+am__cd = CDPATH="$${ZSH_VERSION+.}$(PATH_SEPARATOR)" && cd
+install_sh_DATA = $(install_sh) -c -m 644
+install_sh_PROGRAM = $(install_sh) -c
+install_sh_SCRIPT = $(install_sh) -c
+INSTALL_HEADER = $(INSTALL_DATA)
+transform = $(program_transform_name)
+NORMAL_INSTALL = :
+PRE_INSTALL = :
+POST_INSTALL = :
+NORMAL_UNINSTALL = :
+PRE_UNINSTALL = :
+POST_UNINSTALL = :
+build_triplet = @build@
+host_triplet = @host@
+subdir = doc
+DIST_COMMON = $(m4_TEXINFOS) $(srcdir)/Makefile.am \
+	$(srcdir)/Makefile.in $(srcdir)/stamp-vti \
+	$(srcdir)/version.texi mdate-sh texinfo.tex
+ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
+am__aclocal_m4_deps = $(top_srcdir)/m4/absolute-header.m4 \
+	$(top_srcdir)/m4/alloca.m4 $(top_srcdir)/m4/allocsa.m4 \
+	$(top_srcdir)/m4/cloexec.m4 $(top_srcdir)/m4/close-stream.m4 \
+	$(top_srcdir)/m4/closeout.m4 $(top_srcdir)/m4/codeset.m4 \
+	$(top_srcdir)/m4/config-h.m4 $(top_srcdir)/m4/eealloc.m4 \
+	$(top_srcdir)/m4/eoverflow.m4 $(top_srcdir)/m4/error.m4 \
+	$(top_srcdir)/m4/exitfail.m4 $(top_srcdir)/m4/extensions.m4 \
+	$(top_srcdir)/m4/fatal-signal.m4 $(top_srcdir)/m4/fpending.m4 \
+	$(top_srcdir)/m4/free.m4 $(top_srcdir)/m4/getopt.m4 \
+	$(top_srcdir)/m4/gl_list.m4 $(top_srcdir)/m4/gnulib-comp.m4 \
+	$(top_srcdir)/m4/inline.m4 $(top_srcdir)/m4/intmax_t.m4 \
+	$(top_srcdir)/m4/inttypes_h.m4 $(top_srcdir)/m4/longdouble.m4 \
+	$(top_srcdir)/m4/longlong.m4 $(top_srcdir)/m4/mbchar.m4 \
+	$(top_srcdir)/m4/mbiter.m4 $(top_srcdir)/m4/mbrtowc.m4 \
+	$(top_srcdir)/m4/mbstate_t.m4 $(top_srcdir)/m4/memchr.m4 \
+	$(top_srcdir)/m4/mkdtemp.m4 $(top_srcdir)/m4/mkstemp.m4 \
+	$(top_srcdir)/m4/pathmax.m4 $(top_srcdir)/m4/quotearg.m4 \
+	$(top_srcdir)/m4/regex.m4 $(top_srcdir)/m4/sig_atomic_t.m4 \
+	$(top_srcdir)/m4/signalblocking.m4 \
+	$(top_srcdir)/m4/size_max.m4 $(top_srcdir)/m4/ssize_t.m4 \
+	$(top_srcdir)/m4/stdarg.m4 $(top_srcdir)/m4/stdbool.m4 \
+	$(top_srcdir)/m4/stdint.m4 $(top_srcdir)/m4/stdint_h.m4 \
+	$(top_srcdir)/m4/stdio-safer.m4 \
+	$(top_srcdir)/m4/stdlib-safer.m4 $(top_srcdir)/m4/strcase.m4 \
+	$(top_srcdir)/m4/strstr.m4 $(top_srcdir)/m4/strtol.m4 \
+	$(top_srcdir)/m4/sys_stat_h.m4 $(top_srcdir)/m4/tempname.m4 \
+	$(top_srcdir)/m4/tmpdir.m4 $(top_srcdir)/m4/ulonglong.m4 \
+	$(top_srcdir)/m4/unistd-safer.m4 $(top_srcdir)/m4/unistd_h.m4 \
+	$(top_srcdir)/m4/unlocked-io.m4 $(top_srcdir)/m4/vasnprintf.m4 \
+	$(top_srcdir)/m4/vasprintf.m4 $(top_srcdir)/m4/wchar_t.m4 \
+	$(top_srcdir)/m4/wcwidth.m4 $(top_srcdir)/m4/wint_t.m4 \
+	$(top_srcdir)/m4/xalloc.m4 $(top_srcdir)/m4/xsize.m4 \
+	$(top_srcdir)/m4/xvasprintf.m4 $(top_srcdir)/acinclude.m4 \
+	$(top_srcdir)/configure.ac
+am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
+	$(ACLOCAL_M4)
+mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = $(top_builddir)/lib/config.h
+CONFIG_CLEAN_FILES =
+SOURCES =
+DIST_SOURCES =
+INFO_DEPS = $(srcdir)/m4.info
+am__TEXINFO_TEX_DIR = $(srcdir)
+DVIS = m4.dvi
+PDFS = m4.pdf
+PSS = m4.ps
+HTMLS = m4.html
+TEXINFOS = m4.texinfo
+TEXI2DVI = texi2dvi
+TEXI2PDF = $(TEXI2DVI) --pdf --batch
+MAKEINFOHTML = $(MAKEINFO) --html
+AM_MAKEINFOHTMLFLAGS = $(AM_MAKEINFOFLAGS)
+DVIPS = dvips
+am__installdirs = "$(DESTDIR)$(infodir)" "$(DESTDIR)$(man1dir)"
+am__vpath_adj_setup = srcdirstrip=`echo "$(srcdir)" | sed 's|.|.|g'`;
+am__vpath_adj = case $$p in \
+    $(srcdir)/*) f=`echo "$$p" | sed "s|^$$srcdirstrip/||"`;; \
+    *) f=$$p;; \
+  esac;
+am__strip_dir = `echo $$p | sed -e 's|^.*/||'`;
+man1dir = $(mandir)/man1
+NROFF = nroff
+MANS = $(man_MANS)
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+	  esac; \
+	done; \
+	echo ' cd $(top_srcdir) && $(AUTOMAKE) --gnu  doc/Makefile'; \
+	cd $(top_srcdir) && \
+	  $(AUTOMAKE) --gnu  doc/Makefile
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+	@case '$?' in \
+	  *config.status*) \
+	    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
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+	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe)'; \
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+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
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+	cd "$$am__cwd"; \
+	if $(MAKEINFO) $(AM_MAKEINFOFLAGS) $(MAKEINFOFLAGS) -I $(srcdir) \
+	 -o $@ $<; \
+	then \
+	  rc=0; \
+	  cd $(srcdir); \
+	else \
+	  rc=$$?; \
+	  cd $(srcdir) && \
+	  $$restore $$backupdir/* `echo "./$@" | sed 's|[^/]*$$||'`; \
+	fi; \
+	rm -rf $$backupdir; exit $$rc
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+.texinfo.dvi:
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+	$(TEXI2DVI) $<
+
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+	MAKEINFO='$(MAKEINFO) $(AM_MAKEINFOFLAGS) $(MAKEINFOFLAGS) -I $(srcdir)' \
+	$(TEXI2PDF) $<
+
+.texinfo.html:
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+	if $(MAKEINFOHTML) $(AM_MAKEINFOHTMLFLAGS) $(MAKEINFOFLAGS) -I $(srcdir) \
+	 -o $(@:.html=.htp) $<; \
+	then \
+	  rm -rf $@; \
+	  if test ! -d $(@:.html=.htp) && test -d $(@:.html=); then \
+	    mv $(@:.html=) $@; else mv $(@:.html=.htp) $@; fi; \
+	else \
+	  if test ! -d $(@:.html=.htp) && test -d $(@:.html=); then \
+	    rm -rf $(@:.html=); else rm -Rf $(@:.html=.htp) $@; fi; \
+	  exit 1; \
+	fi
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+	echo "@set UPDATED $$1 $$2 $$3"; \
+	echo "@set UPDATED-MONTH $$2 $$3"; \
+	echo "@set EDITION $(VERSION)"; \
+	echo "@set VERSION $(VERSION)") > vti.tmp
+	@cmp -s vti.tmp $(srcdir)/version.texi \
+	  || (echo "Updating $(srcdir)/version.texi"; \
+	      cp vti.tmp $(srcdir)/version.texi)
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+	@cp $(srcdir)/version.texi $@
+
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+	  list='$(INFO_DEPS)'; \
+	  for file in $$list; do \
+	    relfile=`echo "$$file" | sed 's|^.*/||'`; \
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+	@$(NORMAL_UNINSTALL)
+	@list='$(INFO_DEPS)'; \
+	for file in $$list; do \
+	  relfile=`echo "$$file" | sed 's|^.*/||'`; \
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+	list='$(INFO_DEPS)'; \
+	for base in $$list; do \
+	  case $$base in \
+	    $(srcdir)/*) base=`echo "$$base" | sed "s|^$$srcdirstrip/||"`;; \
+	  esac; \
+	  if test -f $$base; then d=.; else d=$(srcdir); fi; \
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+	      relfile=`expr "$$file" : "$$d/\(.*\)"`; \
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+		cp -p $$file $(distdir)/$$relfile; \
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+	  m4.html
+
+maintainer-clean-aminfo:
+	@list='$(INFO_DEPS)'; for i in $$list; do \
+	  i_i=`echo "$$i" | sed 's|\.info$$||;s|$$|.i|'`; \
+	  echo " rm -f $$i $$i-[0-9] $$i-[0-9][0-9] $$i_i[0-9] $$i_i[0-9][0-9]"; \
+	  rm -f $$i $$i-[0-9] $$i-[0-9][0-9] $$i_i[0-9] $$i_i[0-9][0-9]; \
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+	l2='$(man_MANS) $(dist_man_MANS) $(nodist_man_MANS)'; \
+	for i in $$l2; do \
+	  case "$$i" in \
+	    *.1*) list="$$list $$i" ;; \
+	  esac; \
+	done; \
+	for i in $$list; do \
+	  if test -f $(srcdir)/$$i; then file=$(srcdir)/$$i; \
+	  else file=$$i; fi; \
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+	  case "$$ext" in \
+	    1*) ;; \
+	    *) ext='1' ;; \
+	  esac; \
+	  inst=`echo $$i | sed -e 's/\\.[0-9a-z]*$$//'`; \
+	  inst=`echo $$inst | sed -e 's/^.*\///'`; \
+	  inst=`echo $$inst | sed '$(transform)'`.$$ext; \
+	  echo " $(INSTALL_DATA) '$$file' '$(DESTDIR)$(man1dir)/$$inst'"; \
+	  $(INSTALL_DATA) "$$file" "$(DESTDIR)$(man1dir)/$$inst"; \
+	done
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+	l2='$(man_MANS) $(dist_man_MANS) $(nodist_man_MANS)'; \
+	for i in $$l2; do \
+	  case "$$i" in \
+	    *.1*) list="$$list $$i" ;; \
+	  esac; \
+	done; \
+	for i in $$list; do \
+	  ext=`echo $$i | sed -e 's/^.*\\.//'`; \
+	  case "$$ext" in \
+	    1*) ;; \
+	    *) ext='1' ;; \
+	  esac; \
+	  inst=`echo $$i | sed -e 's/\\.[0-9a-z]*$$//'`; \
+	  inst=`echo $$inst | sed -e 's/^.*\///'`; \
+	  inst=`echo $$inst | sed '$(transform)'`.$$ext; \
+	  echo " rm -f '$(DESTDIR)$(man1dir)/$$inst'"; \
+	  rm -f "$(DESTDIR)$(man1dir)/$$inst"; \
+	done
+tags: TAGS
+TAGS:
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+ctags: CTAGS
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+
+distdir: $(DISTFILES)
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+	topsrcdirstrip=`echo "$(top_srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
+	list='$(DISTFILES)'; \
+	  dist_files=`for file in $$list; do echo $$file; done | \
+	  sed -e "s|^$$srcdirstrip/||;t" \
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+	case $$dist_files in \
+	  */*) $(MKDIR_P) `echo "$$dist_files" | \
+			   sed '/\//!d;s|^|$(distdir)/|;s,/[^/]*$$,,' | \
+			   sort -u` ;; \
+	esac; \
+	for file in $$dist_files; do \
+	  if test -f $$file || test -d $$file; then d=.; else d=$(srcdir); fi; \
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+	    if test -d $(srcdir)/$$file && test $$d != $(srcdir); then \
+	      cp -pR $(srcdir)/$$file $(distdir)$$dir || exit 1; \
+	    fi; \
+	    cp -pR $$d/$$file $(distdir)$$dir || exit 1; \
+	  else \
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+	    || cp -p $$d/$$file $(distdir)/$$file \
+	    || exit 1; \
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+	  install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
+	  `test -z '$(STRIP)' || \
+	    echo "INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'"` install
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+
+maintainer-clean-generic:
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+	@srcdirstrip=`echo "$(srcdir)" | sed 's|.|.|g'`; \
+	list='$(INFO_DEPS)'; \
+	for file in $$list; do \
+	  case $$file in \
+	    $(srcdir)/*) file=`echo "$$file" | sed "s|^$$srcdirstrip/||"`;; \
+	  esac; \
+	  if test -f $$file; then d=.; else d=$(srcdir); fi; \
+	  file_i=`echo "$$file" | sed 's|\.info$$||;s|$$|.i|'`; \
+	  for ifile in $$d/$$file $$d/$$file-[0-9] $$d/$$file-[0-9][0-9] \
+                       $$d/$$file_i[0-9] $$d/$$file_i[0-9][0-9] ; do \
+	    if test -f $$ifile; then \
+	      relfile=`echo "$$ifile" | sed 's|^.*/||'`; \
+	      echo " $(INSTALL_DATA) '$$ifile' '$(DESTDIR)$(infodir)/$$relfile'"; \
+	      $(INSTALL_DATA) "$$ifile" "$(DESTDIR)$(infodir)/$$relfile"; \
+	    else : ; fi; \
+	  done; \
+	done
+	@$(POST_INSTALL)
+	@if (install-info --version && \
+	     install-info --version 2>&1 | sed 1q | grep -i -v debian) >/dev/null 2>&1; then \
+	  list='$(INFO_DEPS)'; \
+	  for file in $$list; do \
+	    relfile=`echo "$$file" | sed 's|^.*/||'`; \
+	    echo " install-info --info-dir='$(DESTDIR)$(infodir)' '$(DESTDIR)$(infodir)/$$relfile'";\
+	    install-info --info-dir="$(DESTDIR)$(infodir)" "$(DESTDIR)$(infodir)/$$relfile" || :;\
+	  done; \
+	else : ; fi
+install-man: install-man1
+
+install-pdf: install-pdf-am
+
+install-pdf-am: $(PDFS)
+	@$(NORMAL_INSTALL)
+	test -z "$(pdfdir)" || $(MKDIR_P) "$(DESTDIR)$(pdfdir)"
+	@list='$(PDFS)'; for p in $$list; do \
+	  if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
+	  f=$(am__strip_dir) \
+	  echo " $(INSTALL_DATA) '$$d$$p' '$(DESTDIR)$(pdfdir)/$$f'"; \
+	  $(INSTALL_DATA) "$$d$$p" "$(DESTDIR)$(pdfdir)/$$f"; \
+	done
+install-ps: install-ps-am
+
+install-ps-am: $(PSS)
+	@$(NORMAL_INSTALL)
+	test -z "$(psdir)" || $(MKDIR_P) "$(DESTDIR)$(psdir)"
+	@list='$(PSS)'; for p in $$list; do \
+	  if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
+	  f=$(am__strip_dir) \
+	  echo " $(INSTALL_DATA) '$$d$$p' '$(DESTDIR)$(psdir)/$$f'"; \
+	  $(INSTALL_DATA) "$$d$$p" "$(DESTDIR)$(psdir)/$$f"; \
+	done
+installcheck-am:
+
+maintainer-clean: maintainer-clean-am
+	-rm -f Makefile
+maintainer-clean-am: distclean-am maintainer-clean-aminfo \
+	maintainer-clean-generic maintainer-clean-vti
+
+mostlyclean: mostlyclean-am
+
+mostlyclean-am: mostlyclean-aminfo mostlyclean-generic mostlyclean-vti
+
+pdf: pdf-am
+
+pdf-am: $(PDFS)
+
+ps: ps-am
+
+ps-am: $(PSS)
+
+uninstall-am: uninstall-dvi-am uninstall-html-am uninstall-info-am \
+	uninstall-man uninstall-pdf-am uninstall-ps-am
+
+uninstall-man: uninstall-man1
+
+.MAKE: install-am install-strip
+
+.PHONY: all all-am check check-am clean clean-generic dist-info \
+	distclean distclean-generic distdir dvi dvi-am html html-am \
+	info info-am install install-am install-data install-data-am \
+	install-dvi install-dvi-am install-exec install-exec-am \
+	install-html install-html-am install-info install-info-am \
+	install-man install-man1 install-pdf install-pdf-am install-ps \
+	install-ps-am install-strip installcheck installcheck-am \
+	installdirs maintainer-clean maintainer-clean-aminfo \
+	maintainer-clean-generic maintainer-clean-vti mostlyclean \
+	mostlyclean-aminfo mostlyclean-generic mostlyclean-vti pdf \
+	pdf-am ps ps-am uninstall uninstall-am uninstall-dvi-am \
+	uninstall-html-am uninstall-info-am uninstall-man \
+	uninstall-man1 uninstall-pdf-am uninstall-ps-am
+
+
+# Depend on configure.ac for version, m4.c for usage text.  Do not depend on
+# built m4 executable, since not everyone has help2man or perl.
+# Build the man page once in the srcdir, rather than in every VPATH build
+# dir, to match how automake builds info pages.  This is safe for 'make
+# distcheck' since it is distributed pre-built.
+$(srcdir)/m4.1: $(top_srcdir)/configure.ac $(top_srcdir)/src/m4.c
+	@if test -x ../src/m4$(EXEEXT) ; then \
+	  echo "Updating man page m4.1" ; \
+	  $(SHELL) $(top_srcdir)/missing --run \
+	    help2man --name="macro processor" --source=FSF \
+	      --info-page=m4 --output=$@ ../src/m4$(EXEEXT) ; \
+	else \
+	  echo "WARNING: The \`man' page \`$@' cannot be updated yet."; \
+	  echo "         Retry once the program executable is ready."; \
+	fi
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/src/bin/m4/doc/fdl.texi b/src/bin/m4/doc/fdl.texi
new file mode 100644
index 0000000000..9c6d9afe3f
--- /dev/null
+++ b/src/bin/m4/doc/fdl.texi
@@ -0,0 +1,452 @@
+
+@node GNU Free Documentation License
+@appendixsec GNU Free Documentation License
+
+@cindex FDL, GNU Free Documentation License
+@center Version 1.2, November 2002
+
+@display
+Copyright @copyright{} 2000,2001,2002 Free Software Foundation, Inc.
+51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
+
+Everyone is permitted to copy and distribute verbatim copies
+of this license document, but changing it is not allowed.
+@end display
+
+@enumerate 0
+@item
+PREAMBLE
+
+The purpose of this License is to make a manual, textbook, or other
+functional and useful document @dfn{free} in the sense of freedom: to
+assure everyone the effective freedom to copy and redistribute it,
+with or without modifying it, either commercially or noncommercially.
+Secondarily, this License preserves for the author and publisher a way
+to get credit for their work, while not being considered responsible
+for modifications made by others.
+
+This License is a kind of ``copyleft'', which means that derivative
+works of the document must themselves be free in the same sense.  It
+complements the GNU General Public License, which is a copyleft
+license designed for free software.
+
+We have designed this License in order to use it for manuals for free
+software, because free software needs free documentation: a free
+program should come with manuals providing the same freedoms that the
+software does.  But this License is not limited to software manuals;
+it can be used for any textual work, regardless of subject matter or
+whether it is published as a printed book.  We recommend this License
+principally for works whose purpose is instruction or reference.
+
+@item
+APPLICABILITY AND DEFINITIONS
+
+This License applies to any manual or other work, in any medium, that
+contains a notice placed by the copyright holder saying it can be
+distributed under the terms of this License.  Such a notice grants a
+world-wide, royalty-free license, unlimited in duration, to use that
+work under the conditions stated herein.  The ``Document'', below,
+refers to any such manual or work.  Any member of the public is a
+licensee, and is addressed as ``you''.  You accept the license if you
+copy, modify or distribute the work in a way requiring permission
+under copyright law.
+
+A ``Modified Version'' of the Document means any work containing the
+Document or a portion of it, either copied verbatim, or with
+modifications and/or translated into another language.
+
+A ``Secondary Section'' is a named appendix or a front-matter section
+of the Document that deals exclusively with the relationship of the
+publishers or authors of the Document to the Document's overall
+subject (or to related matters) and contains nothing that could fall
+directly within that overall subject.  (Thus, if the Document is in
+part a textbook of mathematics, a Secondary Section may not explain
+any mathematics.)  The relationship could be a matter of historical
+connection with the subject or with related matters, or of legal,
+commercial, philosophical, ethical or political position regarding
+them.
+
+The ``Invariant Sections'' are certain Secondary Sections whose titles
+are designated, as being those of Invariant Sections, in the notice
+that says that the Document is released under this License.  If a
+section does not fit the above definition of Secondary then it is not
+allowed to be designated as Invariant.  The Document may contain zero
+Invariant Sections.  If the Document does not identify any Invariant
+Sections then there are none.
+
+The ``Cover Texts'' are certain short passages of text that are listed,
+as Front-Cover Texts or Back-Cover Texts, in the notice that says that
+the Document is released under this License.  A Front-Cover Text may
+be at most 5 words, and a Back-Cover Text may be at most 25 words.
+
+A ``Transparent'' copy of the Document means a machine-readable copy,
+represented in a format whose specification is available to the
+general public, that is suitable for revising the document
+straightforwardly with generic text editors or (for images composed of
+pixels) generic paint programs or (for drawings) some widely available
+drawing editor, and that is suitable for input to text formatters or
+for automatic translation to a variety of formats suitable for input
+to text formatters.  A copy made in an otherwise Transparent file
+format whose markup, or absence of markup, has been arranged to thwart
+or discourage subsequent modification by readers is not Transparent.
+An image format is not Transparent if used for any substantial amount
+of text.  A copy that is not ``Transparent'' is called ``Opaque''.
+
+Examples of suitable formats for Transparent copies include plain
+@sc{ascii} without markup, Texinfo input format, La@TeX{} input
+format, @acronym{SGML} or @acronym{XML} using a publicly available
+@acronym{DTD}, and standard-conforming simple @acronym{HTML},
+PostScript or @acronym{PDF} designed for human modification.  Examples
+of transparent image formats include @acronym{PNG}, @acronym{XCF} and
+@acronym{JPG}.  Opaque formats include proprietary formats that can be
+read and edited only by proprietary word processors, @acronym{SGML} or
+@acronym{XML} for which the @acronym{DTD} and/or processing tools are
+not generally available, and the machine-generated @acronym{HTML},
+PostScript or @acronym{PDF} produced by some word processors for
+output purposes only.
+
+The ``Title Page'' means, for a printed book, the title page itself,
+plus such following pages as are needed to hold, legibly, the material
+this License requires to appear in the title page.  For works in
+formats which do not have any title page as such, ``Title Page'' means
+the text near the most prominent appearance of the work's title,
+preceding the beginning of the body of the text.
+
+A section ``Entitled XYZ'' means a named subunit of the Document whose
+title either is precisely XYZ or contains XYZ in parentheses following
+text that translates XYZ in another language.  (Here XYZ stands for a
+specific section name mentioned below, such as ``Acknowledgements'',
+``Dedications'', ``Endorsements'', or ``History''.)  To ``Preserve the Title''
+of such a section when you modify the Document means that it remains a
+section ``Entitled XYZ'' according to this definition.
+
+The Document may include Warranty Disclaimers next to the notice which
+states that this License applies to the Document.  These Warranty
+Disclaimers are considered to be included by reference in this
+License, but only as regards disclaiming warranties: any other
+implication that these Warranty Disclaimers may have is void and has
+no effect on the meaning of this License.
+
+@item
+VERBATIM COPYING
+
+You may copy and distribute the Document in any medium, either
+commercially or noncommercially, provided that this License, the
+copyright notices, and the license notice saying this License applies
+to the Document are reproduced in all copies, and that you add no other
+conditions whatsoever to those of this License.  You may not use
+technical measures to obstruct or control the reading or further
+copying of the copies you make or distribute.  However, you may accept
+compensation in exchange for copies.  If you distribute a large enough
+number of copies you must also follow the conditions in section 3.
+
+You may also lend copies, under the same conditions stated above, and
+you may publicly display copies.
+
+@item
+COPYING IN QUANTITY
+
+If you publish printed copies (or copies in media that commonly have
+printed covers) of the Document, numbering more than 100, and the
+Document's license notice requires Cover Texts, you must enclose the
+copies in covers that carry, clearly and legibly, all these Cover
+Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
+the back cover.  Both covers must also clearly and legibly identify
+you as the publisher of these copies.  The front cover must present
+the full title with all words of the title equally prominent and
+visible.  You may add other material on the covers in addition.
+Copying with changes limited to the covers, as long as they preserve
+the title of the Document and satisfy these conditions, can be treated
+as verbatim copying in other respects.
+
+If the required texts for either cover are too voluminous to fit
+legibly, you should put the first ones listed (as many as fit
+reasonably) on the actual cover, and continue the rest onto adjacent
+pages.
+
+If you publish or distribute Opaque copies of the Document numbering
+more than 100, you must either include a machine-readable Transparent
+copy along with each Opaque copy, or state in or with each Opaque copy
+a computer-network location from which the general network-using
+public has access to download using public-standard network protocols
+a complete Transparent copy of the Document, free of added material.
+If you use the latter option, you must take reasonably prudent steps,
+when you begin distribution of Opaque copies in quantity, to ensure
+that this Transparent copy will remain thus accessible at the stated
+location until at least one year after the last time you distribute an
+Opaque copy (directly or through your agents or retailers) of that
+edition to the public.
+
+It is requested, but not required, that you contact the authors of the
+Document well before redistributing any large number of copies, to give
+them a chance to provide you with an updated version of the Document.
+
+@item
+MODIFICATIONS
+
+You may copy and distribute a Modified Version of the Document under
+the conditions of sections 2 and 3 above, provided that you release
+the Modified Version under precisely this License, with the Modified
+Version filling the role of the Document, thus licensing distribution
+and modification of the Modified Version to whoever possesses a copy
+of it.  In addition, you must do these things in the Modified Version:
+
+@enumerate A
+@item
+Use in the Title Page (and on the covers, if any) a title distinct
+from that of the Document, and from those of previous versions
+(which should, if there were any, be listed in the History section
+of the Document).  You may use the same title as a previous version
+if the original publisher of that version gives permission.
+
+@item
+List on the Title Page, as authors, one or more persons or entities
+responsible for authorship of the modifications in the Modified
+Version, together with at least five of the principal authors of the
+Document (all of its principal authors, if it has fewer than five),
+unless they release you from this requirement.
+
+@item
+State on the Title page the name of the publisher of the
+Modified Version, as the publisher.
+
+@item
+Preserve all the copyright notices of the Document.
+
+@item
+Add an appropriate copyright notice for your modifications
+adjacent to the other copyright notices.
+
+@item
+Include, immediately after the copyright notices, a license notice
+giving the public permission to use the Modified Version under the
+terms of this License, in the form shown in the Addendum below.
+
+@item
+Preserve in that license notice the full lists of Invariant Sections
+and required Cover Texts given in the Document's license notice.
+
+@item
+Include an unaltered copy of this License.
+
+@item
+Preserve the section Entitled ``History'', Preserve its Title, and add
+to it an item stating at least the title, year, new authors, and
+publisher of the Modified Version as given on the Title Page.  If
+there is no section Entitled ``History'' in the Document, create one
+stating the title, year, authors, and publisher of the Document as
+given on its Title Page, then add an item describing the Modified
+Version as stated in the previous sentence.
+
+@item
+Preserve the network location, if any, given in the Document for
+public access to a Transparent copy of the Document, and likewise
+the network locations given in the Document for previous versions
+it was based on.  These may be placed in the ``History'' section.
+You may omit a network location for a work that was published at
+least four years before the Document itself, or if the original
+publisher of the version it refers to gives permission.
+
+@item
+For any section Entitled ``Acknowledgements'' or ``Dedications'', Preserve
+the Title of the section, and preserve in the section all the
+substance and tone of each of the contributor acknowledgements and/or
+dedications given therein.
+
+@item
+Preserve all the Invariant Sections of the Document,
+unaltered in their text and in their titles.  Section numbers
+or the equivalent are not considered part of the section titles.
+
+@item
+Delete any section Entitled ``Endorsements''.  Such a section
+may not be included in the Modified Version.
+
+@item
+Do not retitle any existing section to be Entitled ``Endorsements'' or
+to conflict in title with any Invariant Section.
+
+@item
+Preserve any Warranty Disclaimers.
+@end enumerate
+
+If the Modified Version includes new front-matter sections or
+appendices that qualify as Secondary Sections and contain no material
+copied from the Document, you may at your option designate some or all
+of these sections as invariant.  To do this, add their titles to the
+list of Invariant Sections in the Modified Version's license notice.
+These titles must be distinct from any other section titles.
+
+You may add a section Entitled ``Endorsements'', provided it contains
+nothing but endorsements of your Modified Version by various
+parties---for example, statements of peer review or that the text has
+been approved by an organization as the authoritative definition of a
+standard.
+
+You may add a passage of up to five words as a Front-Cover Text, and a
+passage of up to 25 words as a Back-Cover Text, to the end of the list
+of Cover Texts in the Modified Version.  Only one passage of
+Front-Cover Text and one of Back-Cover Text may be added by (or
+through arrangements made by) any one entity.  If the Document already
+includes a cover text for the same cover, previously added by you or
+by arrangement made by the same entity you are acting on behalf of,
+you may not add another; but you may replace the old one, on explicit
+permission from the previous publisher that added the old one.
+
+The author(s) and publisher(s) of the Document do not by this License
+give permission to use their names for publicity for or to assert or
+imply endorsement of any Modified Version.
+
+@item
+COMBINING DOCUMENTS
+
+You may combine the Document with other documents released under this
+License, under the terms defined in section 4 above for modified
+versions, provided that you include in the combination all of the
+Invariant Sections of all of the original documents, unmodified, and
+list them all as Invariant Sections of your combined work in its
+license notice, and that you preserve all their Warranty Disclaimers.
+
+The combined work need only contain one copy of this License, and
+multiple identical Invariant Sections may be replaced with a single
+copy.  If there are multiple Invariant Sections with the same name but
+different contents, make the title of each such section unique by
+adding at the end of it, in parentheses, the name of the original
+author or publisher of that section if known, or else a unique number.
+Make the same adjustment to the section titles in the list of
+Invariant Sections in the license notice of the combined work.
+
+In the combination, you must combine any sections Entitled ``History''
+in the various original documents, forming one section Entitled
+``History''; likewise combine any sections Entitled ``Acknowledgements'',
+and any sections Entitled ``Dedications''.  You must delete all
+sections Entitled ``Endorsements.''
+
+@item
+COLLECTIONS OF DOCUMENTS
+
+You may make a collection consisting of the Document and other documents
+released under this License, and replace the individual copies of this
+License in the various documents with a single copy that is included in
+the collection, provided that you follow the rules of this License for
+verbatim copying of each of the documents in all other respects.
+
+You may extract a single document from such a collection, and distribute
+it individually under this License, provided you insert a copy of this
+License into the extracted document, and follow this License in all
+other respects regarding verbatim copying of that document.
+
+@item
+AGGREGATION WITH INDEPENDENT WORKS
+
+A compilation of the Document or its derivatives with other separate
+and independent documents or works, in or on a volume of a storage or
+distribution medium, is called an ``aggregate'' if the copyright
+resulting from the compilation is not used to limit the legal rights
+of the compilation's users beyond what the individual works permit.
+When the Document is included in an aggregate, this License does not
+apply to the other works in the aggregate which are not themselves
+derivative works of the Document.
+
+If the Cover Text requirement of section 3 is applicable to these
+copies of the Document, then if the Document is less than one half of
+the entire aggregate, the Document's Cover Texts may be placed on
+covers that bracket the Document within the aggregate, or the
+electronic equivalent of covers if the Document is in electronic form.
+Otherwise they must appear on printed covers that bracket the whole
+aggregate.
+
+@item
+TRANSLATION
+
+Translation is considered a kind of modification, so you may
+distribute translations of the Document under the terms of section 4.
+Replacing Invariant Sections with translations requires special
+permission from their copyright holders, but you may include
+translations of some or all Invariant Sections in addition to the
+original versions of these Invariant Sections.  You may include a
+translation of this License, and all the license notices in the
+Document, and any Warranty Disclaimers, provided that you also include
+the original English version of this License and the original versions
+of those notices and disclaimers.  In case of a disagreement between
+the translation and the original version of this License or a notice
+or disclaimer, the original version will prevail.
+
+If a section in the Document is Entitled ``Acknowledgements'',
+``Dedications'', or ``History'', the requirement (section 4) to Preserve
+its Title (section 1) will typically require changing the actual
+title.
+
+@item
+TERMINATION
+
+You may not copy, modify, sublicense, or distribute the Document except
+as expressly provided for under this License.  Any other attempt to
+copy, modify, sublicense or distribute the Document is void, and will
+automatically terminate your rights under this License.  However,
+parties who have received copies, or rights, from you under this
+License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+@item
+FUTURE REVISIONS OF THIS LICENSE
+
+The Free Software Foundation may publish new, revised versions
+of the GNU Free Documentation License from time to time.  Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.  See
+@uref{http://www.gnu.org/copyleft/}.
+
+Each version of the License is given a distinguishing version number.
+If the Document specifies that a particular numbered version of this
+License ``or any later version'' applies to it, you have the option of
+following the terms and conditions either of that specified version or
+of any later version that has been published (not as a draft) by the
+Free Software Foundation.  If the Document does not specify a version
+number of this License, you may choose any version ever published (not
+as a draft) by the Free Software Foundation.
+@end enumerate
+
+@page
+@heading ADDENDUM: How to use this License for your documents
+
+To use this License in a document you have written, include a copy of
+the License in the document and put the following copyright and
+license notices just after the title page:
+
+@smallexample
+@group
+  Copyright (C)  @var{year}  @var{your name}.
+  Permission is granted to copy, distribute and/or modify this document
+  under the terms of the GNU Free Documentation License, Version 1.2
+  or any later version published by the Free Software Foundation;
+  with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
+  Texts.  A copy of the license is included in the section entitled ``GNU
+  Free Documentation License''.
+@end group
+@end smallexample
+
+If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
+replace the ``with...Texts.'' line with this:
+
+@smallexample
+@group
+    with the Invariant Sections being @var{list their titles}, with
+    the Front-Cover Texts being @var{list}, and with the Back-Cover Texts
+    being @var{list}.
+@end group
+@end smallexample
+
+If you have Invariant Sections without Cover Texts, or some other
+combination of the three, merge those two alternatives to suit the
+situation.
+
+If your document contains nontrivial examples of program code, we
+recommend releasing these examples in parallel under your choice of
+free software license, such as the GNU General Public License,
+to permit their use in free software.
+
+@c Local Variables:
+@c ispell-local-pdict: "ispell-dict"
+@c End:
+
diff --git a/src/bin/m4/doc/gendocs_template b/src/bin/m4/doc/gendocs_template
new file mode 100755
index 0000000000..71fc286c96
--- /dev/null
+++ b/src/bin/m4/doc/gendocs_template
@@ -0,0 +1,91 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
+    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
+
+<head>
+<title>%%TITLE%% - GNU Project - Free Software Foundation (FSF)</title>
+<meta http-equiv="content-type" content='text/html; charset=utf-8' />
+<link rel="stylesheet" type="text/css" href="/gnu.css" />
+<link rev="made" href="webmasters@gnu.org" />
+</head>
+
+<!-- This document is in XML, and xhtml 1.0 -->
+<!-- Please make sure to properly nest your tags -->
+<!-- and ensure that your final document validates -->
+<!-- consistent with W3C xhtml 1.0 and CSS standards -->
+<!-- See validator.w3.org -->
+
+<body>
+
+<h3>%%TITLE%%</h3>
+
+<address>Free Software Foundation</address>
+<address>last updated %%DATE%%</address>
+<p>
+<a href="/graphics/gnu-head.jpg">
+	<img src="/graphics/gnu-head-sm.jpg"
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diff --git a/src/bin/m4/doc/m4.1 b/src/bin/m4/doc/m4.1
new file mode 100644
index 0000000000..66e175f36b
--- /dev/null
+++ b/src/bin/m4/doc/m4.1
@@ -0,0 +1,136 @@
+.\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.35.
+.TH M4 "1" "November 2006" "FSF" "User Commands"
+.SH NAME
+M4 \- macro processor
+.SH SYNOPSIS
+.B m4
+[\fIOPTION\fR]... [\fIFILE\fR]...
+.SH DESCRIPTION
+Process macros in FILEs.  If no FILE or if FILE is `\-', standard input
+is read.
+.PP
+Mandatory or optional arguments to long options are mandatory or optional
+for short options too.
+.SS "Operation modes:"
+.TP
+\fB\-\-help\fR
+display this help and exit
+.TP
+\fB\-\-version\fR
+output version information and exit
+.TP
+\fB\-E\fR, \fB\-\-fatal\-warnings\fR
+stop execution after first warning
+.TP
+\fB\-i\fR, \fB\-\-interactive\fR
+unbuffer output, ignore interrupts
+.TP
+\fB\-P\fR, \fB\-\-prefix\-builtins\fR
+force a `m4_' prefix to all builtins
+.TP
+\fB\-Q\fR, \fB\-\-quiet\fR, \fB\-\-silent\fR
+suppress some warnings for builtins
+.SS "Preprocessor features:"
+.TP
+\fB\-D\fR, \fB\-\-define=NAME\fR[=\fIVALUE\fR]
+define NAME as having VALUE, or empty
+.TP
+\fB\-I\fR, \fB\-\-include\fR=\fIDIRECTORY\fR
+append DIRECTORY to include path
+.TP
+\fB\-s\fR, \fB\-\-synclines\fR
+generate `#line NUM "FILE"' lines
+.TP
+\fB\-U\fR, \fB\-\-undefine\fR=\fINAME\fR
+undefine NAME
+.SS "Limits control:"
+.TP
+\fB\-G\fR, \fB\-\-traditional\fR
+suppress all GNU extensions
+.TP
+\fB\-H\fR, \fB\-\-hashsize\fR=\fIPRIME\fR
+set symbol lookup hash table size [509]
+.TP
+\fB\-L\fR, \fB\-\-nesting\-limit\fR=\fINUMBER\fR
+change artificial nesting limit [1024]
+.SS "Frozen state files:"
+.TP
+\fB\-F\fR, \fB\-\-freeze\-state\fR=\fIFILE\fR
+produce a frozen state on FILE at end
+.TP
+\fB\-R\fR, \fB\-\-reload\-state\fR=\fIFILE\fR
+reload a frozen state from FILE at start
+.SS "Debugging:"
+.TP
+\fB\-d\fR, \fB\-\-debug\fR[=\fIFLAGS\fR]
+set debug level (no FLAGS implies `aeq')
+.TP
+\fB\-\-debugfile\fR=\fIFILE\fR
+redirect debug and trace output
+.TP
+\fB\-l\fR, \fB\-\-arglength\fR=\fINUM\fR
+restrict macro tracing size
+.TP
+\fB\-t\fR, \fB\-\-trace\fR=\fINAME\fR
+trace NAME when it is defined
+.SS "FLAGS is any of:"
+.TP
+a
+show actual arguments
+.TP
+c
+show before collect, after collect and after call
+.TP
+e
+show expansion
+.TP
+f
+say current input file name
+.TP
+i
+show changes in input files
+.TP
+l
+say current input line number
+.TP
+p
+show results of path searches
+.TP
+q
+quote values as necessary, with a or e flag
+.TP
+t
+trace for all macro calls, not only traceon'ed
+.TP
+x
+add a unique macro call id, useful with c flag
+.TP
+V
+shorthand for all of the above flags
+.PP
+If defined, the environment variable `M4PATH' is a colon\-separated list
+of directories included after any specified by `\-I'.
+.PP
+Exit status is 0 for success, 1 for failure, 63 for frozen file version
+mismatch, or whatever value was passed to the m4exit macro.
+.SH AUTHOR
+Written by Rene' Seindal.
+.SH "REPORTING BUGS"
+Report bugs to <bug\-m4@gnu.org>.
+.SH COPYRIGHT
+Copyright \(co 2006 Free Software Foundation, Inc.
+.br
+This is free software; see the source for copying conditions.  There is NO
+warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+.SH "SEE ALSO"
+The full documentation for
+.B M4
+is maintained as a Texinfo manual.  If the
+.B info
+and
+.B M4
+programs are properly installed at your site, the command
+.IP
+.B info m4
+.PP
+should give you access to the complete manual.
diff --git a/src/bin/m4/doc/m4.info b/src/bin/m4/doc/m4.info
new file mode 100644
index 0000000000..051ca7b79a
--- /dev/null
+++ b/src/bin/m4/doc/m4.info
@@ -0,0 +1,6116 @@
+This is m4.info, produced by makeinfo version 4.8 from m4.texinfo.
+
+   This manual is for GNU M4 (version 1.4.8, 20 November 2006), a
+package containing an implementation of the m4 macro language.
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006
+Free Software Foundation, Inc.
+
+     Permission is granted to copy, distribute and/or modify this
+     document under the terms of the GNU Free Documentation License,
+     Version 1.2 or any later version published by the Free Software
+     Foundation; with no Invariant Sections, no Front-Cover Texts, and
+     no Back-Cover Texts.  A copy of the license is included in the
+     section entitled "GNU Free Documentation License."
+
+INFO-DIR-SECTION GNU programming tools
+START-INFO-DIR-ENTRY
+* M4: (m4).                     A powerful macro processor.
+END-INFO-DIR-ENTRY
+
+
+File: m4.info,  Node: Top,  Next: Preliminaries,  Up: (dir)
+
+GNU M4
+******
+
+This manual is for GNU M4 (version 1.4.8, 20 November 2006), a package
+containing an implementation of the m4 macro language.
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006
+Free Software Foundation, Inc.
+
+     Permission is granted to copy, distribute and/or modify this
+     document under the terms of the GNU Free Documentation License,
+     Version 1.2 or any later version published by the Free Software
+     Foundation; with no Invariant Sections, no Front-Cover Texts, and
+     no Back-Cover Texts.  A copy of the license is included in the
+     section entitled "GNU Free Documentation License."
+
+   GNU `m4' is an implementation of the traditional UNIX macro
+processor.  It is mostly SVR4 compatible, although it has some
+extensions (for example, handling more than 9 positional parameters to
+macros).  `m4' also has builtin functions for including files, running
+shell commands, doing arithmetic, etc.  Autoconf needs GNU `m4' for
+generating `configure' scripts, but not for running them.
+
+   GNU `m4' was originally written by Rene' Seindal, with subsequent
+changes by Franc,ois Pinard and other volunteers on the Internet.  All
+names and email addresses can be found in the files `m4-1.4.8/AUTHORS'
+and `m4-1.4.8/THANKS' from the GNU M4 distribution.
+
+   This is release 1.4.8.  It is now considered stable:  future
+releases in the 1.4.x series are only meant to fix bugs, increase speed,
+or improve documentation.  However...
+
+   An experimental feature, which would improve `m4' usefulness, allows
+for changing the syntax for what is a "word" in `m4'.  You should use:
+     ./configure --enable-changeword
+   if you want this feature compiled in.  The current implementation
+slows down `m4' considerably and is hardly acceptable.  In the future,
+`m4' 2.0 will come with a different set of new features that provide
+similar capabilities, but without the inefficiencies, so changeword
+will go away and _you should not count on it_.
+
+* Menu:
+
+* Preliminaries::               Introduction and preliminaries
+* Invoking m4::                 Invoking `m4'
+* Syntax::                      Lexical and syntactic conventions
+
+* Macros::                      How to invoke macros
+* Definitions::                 How to define new macros
+* Conditionals::                Conditionals, loops, and recursion
+
+* Debugging::                   How to debug macros and input
+
+* Input Control::               Input control
+* File Inclusion::              File inclusion
+* Diversions::                  Diverting and undiverting output
+
+* Text handling::               Macros for text handling
+* Arithmetic::                  Macros for doing arithmetic
+* Shell commands::              Macros for running shell commands
+* Miscellaneous::               Miscellaneous builtin macros
+* Frozen files::                Fast loading of frozen state
+
+* Compatibility::               Compatibility with other versions of `m4'
+* Answers::                     Correct version of some examples
+* Copying This Manual::         How to make copies of this manual
+* Indices::                     Indices of concepts and macros
+
+ --- The Detailed Node Listing ---
+
+Introduction and preliminaries
+
+* Intro::                       Introduction to `m4'
+* History::                     Historical references
+* Bugs::                        Problems and bugs
+* Manual::                      Using this manual
+
+Invoking `m4'
+
+* Operation modes::             Command line options for operation modes
+* Preprocessor features::       Command line options for preprocessor features
+* Limits control::              Command line options for limits control
+* Frozen state::                Command line options for frozen state
+* Debugging options::           Command line options for debugging
+* Command line files::          Specifying input files on the command line
+
+Lexical and syntactic conventions
+
+* Names::                       Macro names
+* Quoted strings::              Quoting input to `m4'
+* Comments::                    Comments in `m4' input
+* Other tokens::                Other kinds of input tokens
+* Input processing::            How `m4' copies input to output
+
+How to invoke macros
+
+* Invocation::                  Macro invocation
+* Inhibiting Invocation::       Preventing macro invocation
+* Macro Arguments::             Macro arguments
+* Quoting Arguments::           On Quoting Arguments to macros
+* Macro expansion::             Expanding macros
+
+How to define new macros
+
+* Define::                      Defining a new macro
+* Arguments::                   Arguments to macros
+* Pseudo Arguments::            Special arguments to macros
+* Undefine::                    Deleting a macro
+* Defn::                        Renaming macros
+* Pushdef::                     Temporarily redefining macros
+
+* Indir::                       Indirect call of macros
+* Builtin::                     Indirect call of builtins
+
+Conditionals, loops, and recursion
+
+* Ifdef::                       Testing if a macro is defined
+* Ifelse::                      If-else construct, or multibranch
+* Shift::                       Recursion in `m4'
+* Forloop::                     Iteration by counting
+* Foreach::                     Iteration by list contents
+
+How to debug macros and input
+
+* Dumpdef::                     Displaying macro definitions
+* Trace::                       Tracing macro calls
+* Debug Levels::                Controlling debugging output
+* Debug Output::                Saving debugging output
+
+Input control
+
+* Dnl::                         Deleting whitespace in input
+* Changequote::                 Changing the quote characters
+* Changecom::                   Changing the comment delimiters
+* Changeword::                  Changing the lexical structure of words
+* M4wrap::                      Saving text until end of input
+
+File inclusion
+
+* Include::                     Including named files
+* Search Path::                 Searching for include files
+
+Diverting and undiverting output
+
+* Divert::                      Diverting output
+* Undivert::                    Undiverting output
+* Divnum::                      Diversion numbers
+* Cleardivert::                 Discarding diverted text
+
+Macros for text handling
+
+* Len::                         Calculating length of strings
+* Index macro::                 Searching for substrings
+* Regexp::                      Searching for regular expressions
+* Substr::                      Extracting substrings
+* Translit::                    Translating characters
+* Patsubst::                    Substituting text by regular expression
+* Format::                      Formatting strings (printf-like)
+
+Macros for doing arithmetic
+
+* Incr::                        Decrement and increment operators
+* Eval::                        Evaluating integer expressions
+
+Macros for running shell commands
+
+* Platform macros::             Determining the platform
+* Syscmd::                      Executing simple commands
+* Esyscmd::                     Reading the output of commands
+* Sysval::                      Exit status
+* Mkstemp::                     Making temporary files
+
+Miscellaneous builtin macros
+
+* Errprint::                    Printing error messages
+* Location::                    Printing current location
+* M4exit::                      Exiting from `m4'
+
+Fast loading of frozen state
+
+* Using frozen files::          Using frozen files
+* Frozen file format::          Frozen file format
+
+Compatibility with other versions of `m4'
+
+* Extensions::                  Extensions in GNU M4
+* Incompatibilities::           Facilities in System V m4 not in GNU M4
+* Other Incompatibilities::     Other incompatibilities
+
+Correct version of some examples
+
+* Improved exch::               Solution for `exch'
+* Improved forloop::            Solution for `forloop'
+* Improved foreach::            Solution for `foreach'
+* Improved cleardivert::        Solution for `cleardivert'
+* Improved fatal_error::        Solution for `fatal_error'
+
+How to make copies of this manual
+
+* GNU Free Documentation License::  License for copying this manual
+
+Indices of concepts and macros
+
+* Concept index::               Index for many concepts
+* Macro index::                 Index for all `m4' macros
+
+
+File: m4.info,  Node: Preliminaries,  Next: Invoking m4,  Prev: Top,  Up: Top
+
+1 Introduction and preliminaries
+********************************
+
+This first chapter explains what GNU `m4' is, where `m4' comes from,
+how to read and use this documentation, how to call the `m4' program,
+and how to report bugs about it.  It concludes by giving tips for
+reading the remainder of the manual.
+
+   The following chapters then detail all the features of the `m4'
+language.
+
+* Menu:
+
+* Intro::                       Introduction to `m4'
+* History::                     Historical references
+* Bugs::                        Problems and bugs
+* Manual::                      Using this manual
+
+
+File: m4.info,  Node: Intro,  Next: History,  Up: Preliminaries
+
+1.1 Introduction to `m4'
+========================
+
+`m4' is a macro processor, in the sense that it copies its input to the
+output, expanding macros as it goes.  Macros are either builtin or
+user-defined, and can take any number of arguments.  Besides just doing
+macro expansion, `m4' has builtin functions for including named files,
+running shell commands, doing integer arithmetic, manipulating text in
+various ways, performing recursion, etc....  `m4' can be used either as
+a front-end to a compiler, or as a macro processor in its own right.
+
+   The `m4' macro processor is widely available on all UNIXes, and has
+been standardized by POSIX.  Usually, only a small percentage of users
+are aware of its existence.  However, those who find it often become
+committed users.  The popularity of GNU Autoconf, which requires GNU
+`m4' for _generating_ `configure' scripts, is an incentive for many to
+install it, while these people will not themselves program in `m4'.
+GNU `m4' is mostly compatible with the System V, Release 3 version,
+except for some minor differences.  *Note Compatibility::, for more
+details.
+
+   Some people find `m4' to be fairly addictive.  They first use `m4'
+for simple problems, then take bigger and bigger challenges, learning
+how to write complex sets of `m4' macros along the way.  Once really
+addicted, users pursue writing of sophisticated `m4' applications even
+to solve simple problems, devoting more time debugging their `m4'
+scripts than doing real work.  Beware that `m4' may be dangerous for
+the health of compulsive programmers.
+
+
+File: m4.info,  Node: History,  Next: Bugs,  Prev: Intro,  Up: Preliminaries
+
+1.2 Historical references
+=========================
+
+`GPM' was an important ancestor of `m4'.  See C. Stratchey: "A General
+Purpose Macro generator", Computer Journal 8,3 (1965), pp. 225 ff.
+`GPM' is also succinctly described into David Gries classic "Compiler
+Construction for Digital Computers".
+
+   The classic B. Kernighan and P.J. Plauger: "Software Tools",
+Addison-Wesley, Inc. (1976) describes and implements a Unix
+macro-processor language, which inspired Dennis Ritchie to write `m3',
+a macro processor for the AP-3 minicomputer.
+
+   Kernighan and Ritchie then joined forces to develop the original
+`m4', as described in "The M4 Macro Processor", Bell Laboratories
+(1977).  It had only 21 builtin macros.
+
+   While `GPM' was more _pure_, `m4' is meant to deal with the true
+intricacies of real life: macros can be recognized without being
+pre-announced, skipping whitespace or end-of-lines is easier, more
+constructs are builtin instead of derived, etc.
+
+   Originally, the Kernighan and Plauger macro-processor, and then
+`m3', formed the engine for the Rational FORTRAN preprocessor, that is,
+the `Ratfor' equivalent of `cpp'.  Later, `m4' was used as a frontend
+for `Ratfor', `C' and `Cobol'.
+
+   Rene' Seindal released his implementation of `m4', GNU `m4', in
+1990, with the aim of removing the artificial limitations in many of
+the traditional `m4' implementations, such as maximum line length,
+macro size, or number of macros.
+
+   The late Professor A. Dain Samples described and implemented a
+further evolution in the form of `M5': "User's Guide to the M5 Macro
+Language: 2nd edition", Electronic Announcement on comp.compilers
+newsgroup (1992).
+
+   Franc,ois Pinard took over maintenance of GNU `m4' in 1992, until
+1994 when he released GNU `m4' 1.4, which was the stable release for 10
+years.  It was at this time that GNU Autoconf decided to require GNU
+`m4' as its underlying engine, since all other implementations of `m4'
+had too many limitations.
+
+   More recently, in 2004, Paul Eggert released 1.4.1 and 1.4.2 which
+addressed some long standing bugs in the venerable 1.4 release.  Then
+in 2005 Gary V. Vaughan collected together the many patches to GNU `m4'
+1.4 that were floating around the net and released 1.4.3 and 1.4.4.
+And in 2006, Eric Blake joined the team and prepared patches for the
+release of 1.4.5, 1.4.6, 1.4.7, and 1.4.8.
+
+   Meanwhile, development has continued on new features for `m4', such
+as dynamic module loading and additional builtins.  When complete, GNU
+`m4' 2.0 will start a new series of releases.
+
+
+File: m4.info,  Node: Bugs,  Next: Manual,  Prev: History,  Up: Preliminaries
+
+1.3 Problems and bugs
+=====================
+
+If you have problems with GNU M4 or think you've found a bug, please
+report it.  Before reporting a bug, make sure you've actually found a
+real bug.  Carefully reread the documentation and see if it really says
+you can do what you're trying to do.  If it's not clear whether you
+should be able to do something or not, report that too; it's a bug in
+the documentation!
+
+   Before reporting a bug or trying to fix it yourself, try to isolate
+it to the smallest possible input file that reproduces the problem.
+Then send us the input file and the exact results `m4' gave you.  Also
+say what you expected to occur; this will help us decide whether the
+problem was really in the documentation.
+
+   Once you've got a precise problem, send e-mail to (Internet)
+<bug-m4@gnu.org>.  Please include the version number of `m4' you are
+using.  You can get this information with the command `m4 --version'.
+Also provide details about the platform you are executing on.
+
+   Non-bug suggestions are always welcome as well.  If you have
+questions about things that are unclear in the documentation or are
+just obscure features, please report them too.
+
+
+File: m4.info,  Node: Manual,  Prev: Bugs,  Up: Preliminaries
+
+1.4 Using this manual
+=====================
+
+This manual contains a number of examples of `m4' input and output, and
+a simple notation is used to distinguish input, output and error
+messages from `m4'.  Examples are set out from the normal text, and
+shown in a fixed width font, like this
+
+     This is an example of an example!
+
+   To distinguish input from output, all output from `m4' is prefixed
+by the string `=>', and all error messages by the string `error-->'.
+Thus
+
+     Example of input line
+     =>Output line from m4
+     error-->and an error message
+
+   The sequence `^D' in an example indicates the end of the input file.
+The majority of these examples are self-contained, and you can run them
+with similar results by invoking `m4 -d'.  In fact, the testsuite that
+is bundled in the GNU M4 package consists of the examples in this
+document!
+
+   As each of the predefined macros in `m4' is described, a prototype
+call of the macro will be shown, giving descriptive names to the
+arguments, e.g.,
+
+ -- Composite: example (STRING, [COUNT = `1'], [ARGUMENT]...)
+     This is a sample prototype.  There is not really a macro named
+     `example', but this documents that if there were, it would be a
+     Composite macro, rather than a Builtin.  It requires at least one
+     argument, STRING.  Remember that in `m4', there must not be a
+     space between the macro name and the opening parenthesis, unless
+     it was intended to call the macro without any arguments.  The
+     brackets around COUNT and ARGUMENT show that these arguments are
+     optional.  If COUNT is omitted, the macro behaves as if count were
+     `1', whereas if ARGUMENT is omitted, the macro behaves as if it
+     were the empty string.  A blank argument is not the same as an
+     omitted argument.  For example, `example(`a')', `example(`a',`1')',
+     and `example(`a',`1',)' would behave identically with COUNT set to
+     `1'; while `example(`a',)' and `example(`a',`')' would explicitly
+     pass the empty string for COUNT.  The ellipses (`...') show that
+     the macro processes additional arguments after ARGUMENT, rather
+     than ignoring them.
+
+   All macro arguments in `m4' are strings, but some are given special
+interpretation, e.g., as numbers, file names, regular expressions, etc.
+The documentation for each macro will state how the parameters are
+interpreted, and what happens if the argument cannot be parsed
+according to the desired interpretation.  Unless specified otherwise, a
+parameter specified to be a number is parsed as a decimal, even if the
+argument has leading zeros; and parsing the empty string as a number
+results in 0 rather than an error, although a warning will be issued.
+
+   This document consistently writes and uses "builtin", without a
+hyphen, as if it were an English word.  This is how the `builtin'
+primitive is spelled within `m4'.
+
+
+File: m4.info,  Node: Invoking m4,  Next: Syntax,  Prev: Preliminaries,  Up: Top
+
+2 Invoking `m4'
+***************
+
+The format of the `m4' command is:
+
+     `m4' [OPTION...] [FILE...]
+
+   All options begin with `-', or if long option names are used, with
+`--'.  A long option name need not be written completely, any
+unambiguous prefix is sufficient.  POSIX requires `m4' to recognize
+arguments intermixed with files, even when `POSIXLY_CORRECT' is set in
+the environment.  Most options take effect at startup regardless of
+their position, but some are documented below as taking effect after
+any files that occurred earlier in the command line.  The argument `--'
+is a marker to denote the end of options.
+
+   With short options, options that do not take arguments may be
+combined into a single command line argument with subsequent options,
+options with mandatory arguments may be provided either as a single
+command line argument or as two arguments, and options with optional
+arguments must be provided as a single argument.  In other words, `m4
+-QPDfoo -d a -d+f' is equivalent to `m4 -Q -P -D foo -d -d+f -- ./a',
+although the latter form is considered canonical.
+
+   With long options, options with mandatory arguments may be provided
+with an equal sign (`=') in a single argument, or as two arguments, and
+options with optional arguments must be provided as a single argument.
+In other words, `m4 --def foo --debug a' is equivalent to `m4
+--define=foo --debug= -- ./a', although the latter form is considered
+canonical (not to mention more robust, in case a future version of `m4'
+introduces an option named `--default').
+
+   `m4' understands the following options, grouped by functionality.
+
+* Menu:
+
+* Operation modes::             Command line options for operation modes
+* Preprocessor features::       Command line options for preprocessor features
+* Limits control::              Command line options for limits control
+* Frozen state::                Command line options for frozen state
+* Debugging options::           Command line options for debugging
+* Command line files::          Specifying input files on the command line
+
+
+File: m4.info,  Node: Operation modes,  Next: Preprocessor features,  Up: Invoking m4
+
+2.1 Command line options for operation modes
+============================================
+
+Several options control the overall operation of `m4':
+
+`--help'
+     Print a help summary on standard output, then immediately exit
+     `m4' without reading any input files or performing any other
+     actions.
+
+`--version'
+     Print the version number of the program on standard output, then
+     immediately exit `m4' without reading any input files or
+     performing any other actions.
+
+`-E'
+`--fatal-warnings'
+     Stop execution and exit `m4' once the first warning has been
+     issued, considering all of them to be fatal.
+
+`-i'
+`--interactive'
+`-e'
+     Makes this invocation of `m4' interactive.  This means that all
+     output will be unbuffered, and interrupts will be ignored.  The
+     spelling `-e' exists for compatibility with other `m4'
+     implementations, and issues a warning because it may be withdrawn
+     in a future version of GNU M4.
+
+`-P'
+`--prefix-builtins'
+     Internally modify _all_ builtin macro names so they all start with
+     the prefix `m4_'.  For example, using this option, one should write
+     `m4_define' instead of `define', and `m4___file__' instead of
+     `__file__'.  This option has no effect if `-R' is also specified.
+
+`-Q'
+`--quiet'
+`--silent'
+     Suppress warnings, such as missing or superfluous arguments in
+     macro calls, or treating the empty string as zero.
+
+`-W REGEXP'
+`--word-regexp=REGEXP'
+     Use REGEXP as an alternative syntax for macro names.  This
+     experimental option will not be present in all GNU `m4'
+     implementations (*note Changeword::).
+
+
+File: m4.info,  Node: Preprocessor features,  Next: Limits control,  Prev: Operation modes,  Up: Invoking m4
+
+2.2 Command line options for preprocessor features
+==================================================
+
+Several options allow `m4' to behave more like a preprocessor.  Macro
+definitions and deletions can be made on the command line, the search
+path can be altered, and the output file can track where the input came
+from.  These features occur with the following options:
+
+`-D NAME[=VALUE]'
+`--define=NAME[=VALUE]'
+     This enters NAME into the symbol table, before any input files are
+     read.  If `=VALUE' is missing, the value is taken to be the empty
+     string.  The VALUE can be any string, and the macro can be defined
+     to take arguments, just as if it was defined from within the
+     input.  This option may be given more than once; order with
+     respect to file names is significant, and redefining the same NAME
+     loses the previous value.
+
+`-I DIRECTORY'
+`--include=DIRECTORY'
+     Make `m4' search DIRECTORY for included files that are not found
+     in the current working directory.  *Note Search Path::, for more
+     details.  This option may be given more than once.
+
+`-s'
+`--synclines'
+     Generate synchronization lines, for use by the C preprocessor or
+     other similar tools.  Order is significant with respect to file
+     names.  This option is useful, for example, when `m4' is used as a
+     front end to a compiler.  Source file name and line number
+     information is conveyed by directives of the form `#line LINENUM
+     "FILE"', which are inserted as needed into the middle of the
+     output.  Such directives mean that the following line originated
+     or was expanded from the contents of input file FILE at line
+     LINENUM.  The `"FILE"' part is often omitted when the file name
+     did not change from the previous directive.
+
+     Synchronization directives are always given on complete lines by
+     themselves.  When a synchronization discrepancy occurs in the
+     middle of an output line, the associated synchronization directive
+     is delayed until the beginning of the next generated line.
+
+`-U NAME'
+`--undefine=NAME'
+     This deletes any predefined meaning NAME might have.  Obviously,
+     only predefined macros can be deleted in this way.  This option
+     may be given more than once; undefining a NAME that does not have a
+     definition is silently ignored.  Order is significant with respect
+     to file names.
+
+
+File: m4.info,  Node: Limits control,  Next: Frozen state,  Prev: Preprocessor features,  Up: Invoking m4
+
+2.3 Command line options for limits control
+===========================================
+
+There are some limits within `m4' that can be tuned.  For
+compatibility, `m4' also accepts some options that control limits in
+other implementations, but which are automatically unbounded (limited
+only by your hardware and operating system constraints) in GNU `m4'.
+
+`-G'
+`--traditional'
+     Suppress all the extensions made in this implementation, compared
+     to the System V version.  *Note Compatibility::, for a list of
+     these.
+
+`-H NUM'
+`--hashsize=NUM'
+     Make the internal hash table for symbol lookup be NUM entries big.
+     For better performance, the number should be prime, but this is not
+     checked.  The default is 509 entries.  It should not be necessary
+     to increase this value, unless you define an excessive number of
+     macros.
+
+`-L NUM'
+`--nesting-limit=NUM'
+     Artificially limit the nesting of macro calls to NUM levels,
+     stopping program execution if this limit is ever exceeded.  When
+     not specified, nesting is limited to 1024 levels.  A value of zero
+     means unlimited; but then heavily nested code could potentially
+     cause a stack overflow.
+
+     The precise effect of this option might be more correctly
+     associated with textual nesting than dynamic recursion.  It has
+     been useful when some complex `m4' input was generated by
+     mechanical means.  Most users would never need this option.  If
+     shown to be obtrusive, this option (which is still experimental)
+     might well disappear.
+
+     This option does _not_ have the ability to break endless
+     rescanning loops, since these do not necessarily consume much
+     memory or stack space.  Through clever usage of rescanning loops,
+     one can request complex, time-consuming computations from `m4'
+     with useful results.  Putting limitations in this area would break
+     `m4' power.  There are many pathological cases:
+     `define(`a', `a')a' is only the simplest example (but *note
+     Compatibility::).  Expecting GNU `m4' to detect these would be a
+     little like expecting a compiler system to detect and diagnose
+     endless loops: it is a quite _hard_ problem in general, if not
+     undecidable!
+
+`-B NUM'
+`-S NUM'
+`-T NUM'
+     These options are present for compatibility with System V `m4', but
+     do nothing in this implementation.  They may disappear in future
+     releases, and issue a warning to that effect.
+
+`-N NUM'
+`--diversions=NUM'
+     These options are present only for compatibility with previous
+     versions of GNU `m4', and were controlling the number of possible
+     diversions which could be used at the same time.  They do nothing,
+     because there is no fixed limit anymore.  They may disappear in
+     future releases, and issue a warning to that effect.
+
+
+File: m4.info,  Node: Frozen state,  Next: Debugging options,  Prev: Limits control,  Up: Invoking m4
+
+2.4 Command line options for frozen state
+=========================================
+
+GNU `m4' comes with a feature of freezing internal state (*note Frozen
+files::).  This can be used to speed up `m4' execution when reusing a
+common initialization script.
+
+`-F FILE'
+`--freeze-state=FILE'
+     Once execution is finished, write out the frozen state on the
+     specified FILE.  It is conventional, but not required, for FILE to
+     end in `.m4f'.
+
+`-R FILE'
+`--reload-state=FILE'
+     Before execution starts, recover the internal state from the
+     specified frozen FILE.  The options `-D', `-U', and `-t' take
+     effect after state is reloaded, but before the input files are
+     read.
+
+
+File: m4.info,  Node: Debugging options,  Next: Command line files,  Prev: Frozen state,  Up: Invoking m4
+
+2.5 Command line options for debugging
+======================================
+
+Finally, there are several options for aiding in debugging `m4' scripts.
+
+`-d[FLAGS]'
+`--debug[=FLAGS]'
+     Set the debug-level according to the flags FLAGS.  The debug-level
+     controls the format and amount of information presented by the
+     debugging functions.  *Note Debug Levels::, for more details on
+     the format and meaning of FLAGS.  If omitted, FLAGS defaults to
+     `aeq'.
+
+`--debugfile=FILE'
+`-o FILE'
+`--error-output=FILE'
+     Redirect `dumpdef' output, debug messages, and trace output to the
+     named FILE.  Warnings, error messages, and `errprint' output are
+     still printed to standard error.  If unspecified, debug output goes
+     to standard error; if empty, debug output is discarded.  *Note
+     Debug Output::, for more details.  The spellings `-o' and
+     `--error-output' are misleading and inconsistent with other GNU
+     tools; for now they are silently accepted as synonyms of
+     `--debugfile', but in a future version of M4, using them will
+     cause a warning to be issued.
+
+`-l NUM'
+`--arglength=NUM'
+     Restrict the size of the output generated by macro tracing to NUM
+     characters per trace line.  If unspecified or zero, output is
+     unlimited.  *Note Debug Levels::, for more details.
+
+`-t NAME'
+`--trace=NAME'
+     This enables tracing for the macro NAME, at any point where it is
+     defined.  NAME need not be defined when this option is given.
+     This option may be given more than once, and order is significant
+     with respect to file names.  *Note Trace::, for more details.
+
+
+File: m4.info,  Node: Command line files,  Prev: Debugging options,  Up: Invoking m4
+
+2.6 Specifying input files on the command line
+==============================================
+
+The remaining arguments on the command line are taken to be input file
+names.  If no names are present, standard input is read.  A file name
+of `-' is taken to mean standard input.  It is conventional, but not
+required, for input files to end in `.m4'.
+
+   The input files are read in the sequence given.  Standard input can
+be read more than once, so the file name `-' may appear multiple times
+on the command line; this makes a difference when input is from a
+terminal or other special file type.  It is an error if an input file
+ends in the middle of argument collection, a comment, or a quoted
+string.
+
+   The options `--define' (`-D'), `--undefine' (`-U'), `--synclines'
+(`-s'), and `--trace' (`-t') only take effect after processing input
+from any file names that occur earlier on the command line.
+
+   If none of the input files invoked `m4exit' (*note M4exit::), the
+exit status of `m4' will be 0 for success, 1 for general failure (such
+as problems with reading an input file), and 63 for version mismatch
+(*note Using frozen files::).
+
+   If you need to read a file whose name starts with a `-', you can
+specify it as `./-file', or use `--' to mark the end of options.
+
+
+File: m4.info,  Node: Syntax,  Next: Macros,  Prev: Invoking m4,  Up: Top
+
+3 Lexical and syntactic conventions
+***********************************
+
+As `m4' reads its input, it separates it into "tokens".  A token is
+either a name, a quoted string, or any single character, that is not a
+part of either a name or a string.  Input to `m4' can also contain
+comments.  GNU `m4' does not yet understand locales; all operations are
+byte-oriented rather than character-oriented.  However, `m4' is
+eight-bit clean, so you can use non-ASCII characters in quoted strings
+(*note Changequote::), comments (*note Changecom::), and macro names
+(*note Indir::), with the exception of the NUL character (the zero byte
+`'\0'').
+
+* Menu:
+
+* Names::                       Macro names
+* Quoted strings::              Quoting input to `m4'
+* Comments::                    Comments in `m4' input
+* Other tokens::                Other kinds of input tokens
+* Input processing::            How `m4' copies input to output
+
+
+File: m4.info,  Node: Names,  Next: Quoted strings,  Up: Syntax
+
+3.1 Macro names
+===============
+
+A name is any sequence of letters, digits, and the character `_'
+(underscore), where the first character is not a digit.  `m4' will use
+the longest such sequence found in the input.  If a name has a macro
+definition, it will be subject to macro expansion (*note Macros::).
+Names are case-sensitive.
+
+   Examples of legal names are: `foo', `_tmp', and `name01'.
+
+
+File: m4.info,  Node: Quoted strings,  Next: Comments,  Prev: Names,  Up: Syntax
+
+3.2 Quoting input to `m4'
+=========================
+
+A quoted string is a sequence of characters surrounded by quote
+strings, defaulting to ``' and `'', where the nested begin and end
+quotes within the string are balanced.  The value of a string token is
+the text, with one level of quotes stripped off.  Thus
+
+     `'
+     =>
+
+is the empty string, and double-quoting turns into single-quoting.
+
+     ``quoted''
+     =>`quoted'
+
+   The quote characters can be changed at any time, using the builtin
+macro `changequote'.  *Note Changequote::, for more information.
+
+
+File: m4.info,  Node: Comments,  Next: Other tokens,  Prev: Quoted strings,  Up: Syntax
+
+3.3 Comments in `m4' input
+==========================
+
+Comments in `m4' are normally delimited by the characters `#' and
+newline.  All characters between the comment delimiters are ignored,
+but the entire comment (including the delimiters) is passed through to
+the output--comments are _not_ discarded by `m4'.
+
+   Comments cannot be nested, so the first newline after a `#' ends the
+comment.  The commenting effect of the begin-comment string can be
+inhibited by quoting it.
+
+     `quoted text' # `commented text'
+     =>quoted text # `commented text'
+     `quoting inhibits' `#' `comments'
+     =>quoting inhibits # comments
+
+   The comment delimiters can be changed to any string at any time,
+using the builtin macro `changecom'.  *Note Changecom::, for more
+information.
+
+
+File: m4.info,  Node: Other tokens,  Next: Input processing,  Prev: Comments,  Up: Syntax
+
+3.4 Other kinds of input tokens
+===============================
+
+Any character, that is neither a part of a name, nor of a quoted string,
+nor a comment, is a token by itself.  When not in the context of macro
+expansion, all of these tokens are just copied to output.  However,
+during macro expansion, whitespace characters (space, tab, newline,
+formfeed, carriage return, vertical tab), parentheses (`(' and `)'),
+comma (`,'), and dollar (`$') have additional roles, explained later.
+
+
+File: m4.info,  Node: Input processing,  Prev: Other tokens,  Up: Syntax
+
+3.5 How `m4' copies input to output
+===================================
+
+As `m4' reads the input token by token, it will copy each token
+directly to the output immediately.
+
+   The exception is when it finds a word with a macro definition.  In
+that case `m4' will calculate the macro's expansion, possibly reading
+more input to get the arguments.  It then inserts the expansion in front
+of the remaining input.  In other words, the resulting text from a macro
+call will be read and parsed into tokens again.
+
+   `m4' expands a macro as soon as possible.  If it finds a macro call
+when collecting the arguments to another, it will expand the second
+call first.  For a running example, examine how `m4' handles this input:
+
+     format(`Result is %d', eval(`2**15'))
+
+First, `m4' sees that the token `format' is a macro name, so it
+collects the tokens `(', ``Result is %d'', `,', and ` ', before
+encountering another potential macro.  Sure enough, `eval' is a macro
+name, so the nested argument collection picks up `(', ``2**15'', and
+`)', invoking the eval macro with the lone argument of `2**15'.  The
+expansion of `eval(2**15)' is `32768', which is then rescanned as the
+five tokens `3', `2', `7', `6', and `8'; and combined with the next
+`)', the format macro now has all its arguments, as if the user had
+typed:
+
+     format(`Result is %d', 32768)
+
+The format macro expands to `Result is 32768', and we have another
+round of scanning for the tokens `Result', ` ', `is', ` ', `3', `2',
+`7', `6', and `8'.  None of these are macros, so the final output is
+
+     =>Result is 32768
+
+   The order in which `m4' expands the macros can be explored using the
+trace facilities of GNU `m4' (*note Trace::).
+
+   This process continues until there are no more macro calls to expand
+and all the input has been consumed.
+
+
+File: m4.info,  Node: Macros,  Next: Definitions,  Prev: Syntax,  Up: Top
+
+4 How to invoke macros
+**********************
+
+This chapter covers macro invocation, macro arguments and how macro
+expansion is treated.
+
+* Menu:
+
+* Invocation::                  Macro invocation
+* Inhibiting Invocation::       Preventing macro invocation
+* Macro Arguments::             Macro arguments
+* Quoting Arguments::           On Quoting Arguments to macros
+* Macro expansion::             Expanding macros
+
+
+File: m4.info,  Node: Invocation,  Next: Inhibiting Invocation,  Up: Macros
+
+4.1 Macro invocation
+====================
+
+Macro invocations has one of the forms
+
+     name
+
+which is a macro invocation without any arguments, or
+
+     name(arg1, arg2, ..., argN)
+
+which is a macro invocation with N arguments.  Macros can have any
+number of arguments.  All arguments are strings, but different macros
+might interpret the arguments in different ways.
+
+   The opening parenthesis _must_ follow the NAME directly, with no
+spaces in between.  If it does not, the macro is called with no
+arguments at all.
+
+   For a macro call to have no arguments, the parentheses _must_ be
+left out.  The macro call
+
+     name()
+
+is a macro call with one argument, which is the empty string, not a call
+with no arguments.
+
+
+File: m4.info,  Node: Inhibiting Invocation,  Next: Macro Arguments,  Prev: Invocation,  Up: Macros
+
+4.2 Preventing macro invocation
+===============================
+
+An innovation of the `m4' language, compared to some of its
+predecessors (like Stratchey's `GPM', for example), is the ability to
+recognize macro calls without resorting to any special, prefixed
+invocation character.  While generally useful, this feature might
+sometimes be the source of spurious, unwanted macro calls.  So, GNU
+`m4' offers several mechanisms or techniques for inhibiting the
+recognition of names as macro calls.
+
+   First of all, many builtin macros cannot meaningfully be called
+without arguments.  For any of these macros, whenever an opening
+parenthesis does not immediately follow their name, the builtin macro
+call is not triggered.  This solves the most usual cases, like for
+`include' or `eval'.  Later in this document, the sentence "This macro
+is recognized only with parameters" refers to this specific provision.
+
+   There is also a command line option (`--prefix-builtins', or `-P',
+*note Invoking m4: Operation modes.) that renames all builtin macros
+with a prefix of `m4_' at startup.  The option has no effect whatsoever
+on user defined macros.  For example, with this option, one has to
+write `m4_dnl' and even `m4_m4exit'.  It also has no effect on whether
+a macro requires parameters.
+
+   Another alternative is to redefine problematic macros to a name less
+likely to cause conflicts, *Note Definitions::.
+
+   If your version of GNU `m4' has the `changeword' feature compiled
+in, it offers far more flexibility in specifying the syntax of macro
+names, both builtin or user-defined.  *Note Changeword::, for more
+information on this experimental feature.
+
+   Of course, the simplest way to prevent a name from being interpreted
+as a call to an existing macro is to quote it.  The remainder of this
+section studies a little more deeply how quoting affects macro
+invocation, and how quoting can be used to inhibit macro invocation.
+
+   Even if quoting is usually done over the whole macro name, it can
+also be done over only a few characters of this name (provided, of
+course, that the unquoted portions are not also a macro).  It is also
+possible to quote the empty string, but this works only _inside_ the
+name.  For example:
+
+     `divert'
+     =>divert
+     `d'ivert
+     =>divert
+     di`ver't
+     =>divert
+     div`'ert
+     =>divert
+
+all yield the string `divert'.  While in both:
+
+     `'divert
+     =>
+     divert`'
+     =>
+
+the `divert' builtin macro will be called, which expands to the empty
+string.
+
+   The output of macro evaluations is always rescanned.  The following
+example would yield the string `de', exactly as if `m4' has been given
+`substr(`abcde', `3', `2')' as input:
+
+     define(`x', `substr(ab')
+     =>
+     define(`y', `cde, `3', `2')')
+     =>
+     x`'y
+     =>de
+
+   Unquoted strings on either side of a quoted string are subject to
+being recognized as macro names.  In the following example, quoting the
+empty string allows for the second `macro' to be recognized as such:
+
+     define(`macro', `m')
+     =>
+     macro(`m')macro
+     =>mmacro
+     macro(`m')`'macro
+     =>mm
+
+   Quoting may prevent recognizing as a macro name the concatenation of
+a macro expansion with the surrounding characters.  In this example:
+
+     define(`macro', `di$1')
+     =>
+     macro(`v')`ert'
+     =>divert
+     macro(`v')ert
+     =>
+
+the input will produce the string `divert'.  When the quotes were
+removed, the `divert' builtin was called instead.
+
+
+File: m4.info,  Node: Macro Arguments,  Next: Quoting Arguments,  Prev: Inhibiting Invocation,  Up: Macros
+
+4.3 Macro arguments
+===================
+
+When a name is seen, and it has a macro definition, it will be expanded
+as a macro.
+
+   If the name is followed by an opening parenthesis, the arguments
+will be collected before the macro is called.  If too few arguments are
+supplied, the missing arguments are taken to be the empty string.
+However, some builtins are documented to behave differently for a
+missing optional argument than for an explicit empty string.  If there
+are too many arguments, the excess arguments are ignored.  Unquoted
+leading whitespace is stripped off all arguments, but whitespace
+generated by a macro expansion or occuring after a macro that expanded
+to an empty string remains intact.  Whitespace includes space, tab,
+newline, carriage return, vertical tab, and formfeed.
+
+     define(`macro', `$1')
+     =>
+     macro( unquoted leading space lost)
+     =>unquoted leading space lost
+     macro(` quoted leading space kept')
+     => quoted leading space kept
+     macro(
+      divert `unquoted space kept after expansion')
+     => unquoted space kept after expansion
+     macro(macro(`
+     ')`whitespace from expansion kept')
+     =>
+     =>whitespace from expansion kept
+     macro(`unquoted trailing whitespace kept'
+     )
+     =>unquoted trailing whitespace kept
+     =>
+
+   Normally `m4' will issue warnings if a builtin macro is called with
+an inappropriate number of arguments, but it can be suppressed with the
+`--quiet' command line option (or `--silent', or `-Q', *note Invoking
+m4: Operation modes.).  For user defined macros, there is no check of
+the number of arguments given.
+
+   Macros are expanded normally during argument collection, and whatever
+commas, quotes and parentheses that might show up in the resulting
+expanded text will serve to define the arguments as well.  Thus, if FOO
+expands to `, b, c', the macro call
+
+     bar(a foo, d)
+
+is a macro call with four arguments, which are `a ', `b', `c' and `d'.
+To understand why the first argument contains whitespace, remember that
+unquoted leading whitespace is never part of an argument, but trailing
+whitespace always is.
+
+   It is possible for a macro's definition to change during argument
+collection, in which case the expansion uses the definition that was in
+effect at the time the opening `(' was seen.
+
+     define(`f', `1')
+     =>
+     f(define(`f', `2'))
+     =>1
+     f
+     =>2
+
+   It is an error if the end of file occurs while collecting arguments.
+
+     hello world
+     =>hello world
+     define(
+     ^D
+     error-->m4:stdin:2: ERROR: end of file in argument list
+
+
+File: m4.info,  Node: Quoting Arguments,  Next: Macro expansion,  Prev: Macro Arguments,  Up: Macros
+
+4.4 On Quoting Arguments to macros
+==================================
+
+Each argument has unquoted leading whitespace removed.  Within each
+argument, all unquoted parentheses must match.  For example, if FOO is
+a macro,
+
+     foo(() (`(') `(')
+
+is a macro call, with one argument, whose value is `() (() ('.  Commas
+separate arguments, except when they occur inside quotes, comments, or
+unquoted parentheses.  *Note Pseudo Arguments::, for examples.
+
+   It is common practice to quote all arguments to macros, unless you
+are sure you want the arguments expanded.  Thus, in the above example
+with the parentheses, the `right' way to do it is like this:
+
+     foo(`() (() (')
+
+   It is, however, in certain cases necessary or convenient to leave out
+quotes for some arguments, and there is nothing wrong in doing it.  It
+just makes life a bit harder, if you are not careful.  For consistency,
+this manual follows the rule of thumb that each layer of parentheses
+introduces another layer of single quoting, except when showing the
+consequences of quoting rules.  This is done even when the quoted string
+cannot be a macro, such as with integers when you have not changed the
+syntax via `changeword' (*note Changeword::).
+
+
+File: m4.info,  Node: Macro expansion,  Prev: Quoting Arguments,  Up: Macros
+
+4.5 Macro expansion
+===================
+
+When the arguments, if any, to a macro call have been collected, the
+macro is expanded, and the expansion text is pushed back onto the input
+(unquoted), and reread.  The expansion text from one macro call might
+therefore result in more macros being called, if the calls are included,
+completely or partially, in the first macro calls' expansion.
+
+   Taking a very simple example, if FOO expands to `bar', and BAR
+expands to `Hello world', the input
+
+     foo
+
+will expand first to `bar', and when this is reread and expanded, into
+`Hello world'.
+
+
+File: m4.info,  Node: Definitions,  Next: Conditionals,  Prev: Macros,  Up: Top
+
+5 How to define new macros
+**************************
+
+Macros can be defined, redefined and deleted in several different ways.
+Also, it is possible to redefine a macro without losing a previous
+value, and bring back the original value at a later time.
+
+* Menu:
+
+* Define::                      Defining a new macro
+* Arguments::                   Arguments to macros
+* Pseudo Arguments::            Special arguments to macros
+* Undefine::                    Deleting a macro
+* Defn::                        Renaming macros
+* Pushdef::                     Temporarily redefining macros
+
+* Indir::                       Indirect call of macros
+* Builtin::                     Indirect call of builtins
+
+
+File: m4.info,  Node: Define,  Next: Arguments,  Up: Definitions
+
+5.1 Defining a macro
+====================
+
+The normal way to define or redefine macros is to use the builtin
+`define':
+
+ -- Builtin: define (NAME, [EXPANSION])
+     Defines NAME to expand to EXPANSION.  If EXPANSION is not given,
+     it is taken to be empty.
+
+     The expansion of `define' is void.  The macro `define' is
+     recognized only with parameters.
+
+   The following example defines the macro FOO to expand to the text
+`Hello World.'.
+
+     define(`foo', `Hello world.')
+     =>
+     foo
+     =>Hello world.
+
+   The empty line in the output is there because the newline is not a
+part of the macro definition, and it is consequently copied to the
+output.  This can be avoided by use of the macro `dnl'.  *Note Dnl::,
+for details.
+
+   The first argument to `define' should be quoted; otherwise, if the
+macro is already defined, you will be defining a different macro.  This
+example shows the problems with underquoting, since we did not want to
+redefine `one':
+
+     define(foo, one)
+     =>
+     define(foo, two)
+     =>
+     one
+     =>two
+
+   GNU `m4' normally replaces only the _topmost_ definition of a macro
+if it has several definitions from `pushdef' (*note Pushdef::).  Some
+other implementations of `m4' replace all definitions of a macro with
+`define'.  *Note Incompatibilities::, for more details.
+
+   As a GNU extension, the first argument to `define' does not have to
+be a simple word.  It can be any text string, even the empty string.  A
+macro with a non-standard name cannot be invoked in the normal way, as
+the name is not recognized.  It can only be referenced by the builtins
+`Indir' (*note Indir::) and `Defn' (*note Defn::).
+
+   Arrays and associative arrays can be simulated by using this trick.
+
+     define(`array', `defn(format(``array[%d]'', `$1'))')
+     =>
+     define(`array_set', `define(format(``array[%d]'', `$1'), `$2')')
+     =>
+     array_set(`4', `array element no. 4')
+     =>
+     array_set(`17', `array element no. 17')
+     =>
+     array(`4')
+     =>array element no. 4
+     array(eval(`10 + 7'))
+     =>array element no. 17
+
+   Change the `%d' to `%s' and it is an associative array.
+
+
+File: m4.info,  Node: Arguments,  Next: Pseudo Arguments,  Prev: Define,  Up: Definitions
+
+5.2 Arguments to macros
+=======================
+
+Macros can have arguments.  The Nth argument is denoted by `$n' in the
+expansion text, and is replaced by the Nth actual argument, when the
+macro is expanded.  Replacement of arguments happens before rescanning,
+regardless of how many nesting levels of quoting appear in the
+expansion.  Here is an example of a macro with two arguments.  It
+simply exchanges the order of the two arguments.
+
+     define(`exch', `$2, $1')
+     =>
+     exch(`arg1', `arg2')
+     =>arg2, arg1
+
+   This can be used, for example, if you like the arguments to `define'
+to be reversed.
+
+     define(`exch', `$2, $1')
+     =>
+     define(exch(``expansion text'', ``macro''))
+     =>
+     macro
+     =>expansion text
+
+   *Note Quoting Arguments::, for an explanation of the double quotes.
+(You should try and improve this example so that clients of `exch' do
+not have to double quote; or *note Answers: Improved exch.).
+
+   GNU `m4' allows the number following the `$' to consist of one or
+more digits, allowing macros to have any number of arguments.  This is
+not so in UNIX implementations of `m4', which only recognize one digit.
+
+   As a special case, the zeroth argument, `$0', is always the name of
+the macro being expanded.
+
+     define(`test', ``Macro name: $0'')
+     =>
+     test
+     =>Macro name: test
+
+   If you want quoted text to appear as part of the expansion text,
+remember that quotes can be nested in quoted strings.  Thus, in
+
+     define(`foo', `This is macro `foo'.')
+     =>
+     foo
+     =>This is macro foo.
+
+The `foo' in the expansion text is _not_ expanded, since it is a quoted
+string, and not a name.
+
+
+File: m4.info,  Node: Pseudo Arguments,  Next: Undefine,  Prev: Arguments,  Up: Definitions
+
+5.3 Special arguments to macros
+===============================
+
+There is a special notation for the number of actual arguments supplied,
+and for all the actual arguments.
+
+   The number of actual arguments in a macro call is denoted by `$#' in
+the expansion text.  Thus, a macro to display the number of arguments
+given can be
+
+     define(`nargs', `$#')
+     =>
+     nargs
+     =>0
+     nargs()
+     =>1
+     nargs(`arg1', `arg2', `arg3')
+     =>3
+     nargs(`commas can be quoted, like this')
+     =>1
+     nargs(arg1#inside comments, commas do not separate arguments
+     still arg1)
+     =>1
+     nargs((unquoted parentheses, like this, group arguments))
+     =>1
+
+   The notation `$*' can be used in the expansion text to denote all
+the actual arguments, unquoted, with commas in between.  For example
+
+     define(`echo', `$*')
+     =>
+     echo(arg1,    arg2, arg3 , arg4)
+     =>arg1,arg2,arg3 ,arg4
+
+   Often each argument should be quoted, and the notation `$@' handles
+that.  It is just like `$*', except that it quotes each argument.  A
+simple example of that is:
+
+     define(`echo', `$@')
+     =>
+     echo(arg1,    arg2, arg3 , arg4)
+     =>arg1,arg2,arg3 ,arg4
+
+   Where did the quotes go?  Of course, they were eaten, when the
+expanded text were reread by `m4'.  To show the difference, try
+
+     define(`echo1', `$*')
+     =>
+     define(`echo2', `$@')
+     =>
+     define(`foo', `This is macro `foo'.')
+     =>
+     echo1(foo)
+     =>This is macro This is macro foo..
+     echo1(`foo')
+     =>This is macro foo.
+     echo2(foo)
+     =>This is macro foo.
+     echo2(`foo')
+     =>foo
+
+*Note Trace::, if you do not understand this.  As another example of the
+difference, remember that comments encountered in arguments are passed
+untouched to the macro, and that quoting disables comments.
+
+     define(`echo1', `$*')
+     =>
+     define(`echo2', `$@')
+     =>
+     define(`foo', `bar')
+     =>
+     echo1(#foo'foo
+     foo)
+     =>#foo'foo
+     =>bar
+     echo2(#foo'foo
+     foo)
+     =>#foobar
+     =>bar'
+
+   A `$' sign in the expansion text, that is not followed by anything
+`m4' understands, is simply copied to the macro expansion, as any other
+text is.
+
+     define(`foo', `$$$ hello $$$')
+     =>
+     foo
+     =>$$$ hello $$$
+
+   If you want a macro to expand to something like `$12', the judicious
+use of nested quoting can put a safe character between the `$' and the
+next character, relying on the rescanning to remove the nested quote.
+This will prevent `m4' from interpreting the `$' sign as a reference to
+an argument.
+
+     define(`foo', `no nested quote: $1')
+     =>
+     foo(`arg')
+     =>no nested quote: arg
+     define(`foo', `nested quote around $: `$'1')
+     =>
+     foo(`arg')
+     =>nested quote around $: $1
+     define(`foo', `nested empty quote after $: $`'1')
+     =>
+     foo(`arg')
+     =>nested empty quote after $: $1
+     define(`foo', `nested quote around next character: $`1'')
+     =>
+     foo(`arg')
+     =>nested quote around next character: $1
+     define(`foo', `nested quote around both: `$1'')
+     =>
+     foo(`arg')
+     =>nested quote around both: arg
+
+
+File: m4.info,  Node: Undefine,  Next: Defn,  Prev: Pseudo Arguments,  Up: Definitions
+
+5.4 Deleting a macro
+====================
+
+A macro definition can be removed with `undefine':
+
+ -- Builtin: undefine (NAME...)
+     For each argument, remove the macro NAME.  The macro names must
+     necessarily be quoted, since they will be expanded otherwise.
+
+     The expansion of `undefine' is void.  The macro `undefine' is
+     recognized only with parameters.
+
+     foo bar blah
+     =>foo bar blah
+     define(`foo', `some')define(`bar', `other')define(`blah', `text')
+     =>
+     foo bar blah
+     =>some other text
+     undefine(`foo')
+     =>
+     foo bar blah
+     =>foo other text
+     undefine(`bar', `blah')
+     =>
+     foo bar blah
+     =>foo bar blah
+
+   Undefining a macro inside that macro's expansion is safe; the macro
+still expands to the definition that was in effect at the `('.
+
+     define(`f', ``$0':$1')
+     =>
+     f(f(f(undefine(`f')`hello world')))
+     =>f:f:f:hello world
+     f(`bye')
+     =>f(bye)
+
+   It is not an error for NAME to have no macro definition.  In that
+case, `undefine' does nothing.
+
+
+File: m4.info,  Node: Defn,  Next: Pushdef,  Prev: Undefine,  Up: Definitions
+
+5.5 Renaming macros
+===================
+
+It is possible to rename an already defined macro.  To do this, you need
+the builtin `defn':
+
+ -- Builtin: defn (NAME)
+     Expands to the _quoted definition_ of NAME.  If the argument is
+     not a defined macro, the expansion is void.
+
+     If NAME is a user-defined macro, the quoted definition is simply
+     the quoted expansion text.  If, instead, NAME is a builtin, the
+     expansion is a special token, which points to the builtin's
+     internal definition.  This token is only meaningful as the second
+     argument to `define' (and `pushdef'), and is silently converted to
+     an empty string in most other contexts.
+
+     The macro `defn' is recognized only with parameters.
+
+   Its normal use is best understood through an example, which shows
+how to rename `undefine' to `zap':
+
+     define(`zap', defn(`undefine'))
+     =>
+     zap(`undefine')
+     =>
+     undefine(`zap')
+     =>undefine(zap)
+
+   In this way, `defn' can be used to copy macro definitions, and also
+definitions of builtin macros.  Even if the original macro is removed,
+the other name can still be used to access the definition.
+
+   The fact that macro definitions can be transferred also explains why
+you should use `$0', rather than retyping a macro's name in its
+definition:
+
+     define(`foo', `This is `$0'')
+     =>
+     define(`bar', defn(`foo'))
+     =>
+     bar
+     =>This is bar
+
+   Macros used as string variables should be referred through `defn',
+to avoid unwanted expansion of the text:
+
+     define(`string', `The macro dnl is very useful
+     ')
+     =>
+     string
+     =>The macro 
+     defn(`string')
+     =>The macro dnl is very useful
+     =>
+
+   However, it is important to remember that `m4' rescanning is purely
+textual.  If an unbalanced end-quote string occurs in a macro
+definition, the rescan will see that embedded quote as the termination
+of the quoted string, and the remainder of the macro's definition will
+be rescanned unquoted.  Thus it is a good idea to avoid unbalanced
+end-quotes in macro definitions or arguments to macros.
+
+     define(`foo', a'a)
+     =>
+     define(`a', `A')
+     =>
+     define(`echo', `$@')
+     =>
+     foo
+     =>A'A
+     defn(`foo')
+     =>aA'
+     echo(foo)
+     =>AA'
+
+   Using `defn' to generate special tokens for builtin macros outside
+of expected contexts can sometimes trigger warnings.  But most of the
+time, such tokens are silently converted to the empty string.
+
+     defn(`defn')
+     =>
+     define(defn(`divnum'), `cannot redefine a builtin token')
+     error-->m4:stdin:2: Warning: define: invalid macro name ignored
+     =>
+     divnum
+     =>0
+
+
+File: m4.info,  Node: Pushdef,  Next: Indir,  Prev: Defn,  Up: Definitions
+
+5.6 Temporarily redefining macros
+=================================
+
+It is possible to redefine a macro temporarily, reverting to the
+previous definition at a later time.  This is done with the builtins
+`pushdef' and `popdef':
+
+ -- Builtin: pushdef (NAME, [EXPANSION])
+ -- Builtin: popdef (NAME...)
+     Analogous to `define' and `undefine'.
+
+     These macros work in a stack-like fashion.  A macro is temporarily
+     redefined with `pushdef', which replaces an existing definition of
+     NAME, while saving the previous definition, before the new one is
+     installed.  If there is no previous definition, `pushdef' behaves
+     exactly like `define'.
+
+     If a macro has several definitions (of which only one is
+     accessible), the topmost definition can be removed with `popdef'.
+     If there is no previous definition, `popdef' behaves like
+     `undefine'.
+
+     The expansion of both `pushdef' and `popdef' is void.  The macros
+     `pushdef' and `popdef' are recognized only with parameters.
+
+     define(`foo', `Expansion one.')
+     =>
+     foo
+     =>Expansion one.
+     pushdef(`foo', `Expansion two.')
+     =>
+     foo
+     =>Expansion two.
+     pushdef(`foo', `Expansion three.')
+     =>
+     pushdef(`foo', `Expansion four.')
+     =>
+     popdef(`foo')
+     =>
+     foo
+     =>Expansion three.
+     popdef(`foo', `foo')
+     =>
+     foo
+     =>Expansion one.
+     popdef(`foo')
+     =>
+     foo
+     =>foo
+
+   If a macro with several definitions is redefined with `define', the
+topmost definition is _replaced_ with the new definition.  If it is
+removed with `undefine', _all_ the definitions are removed, and not
+only the topmost one.
+
+     define(`foo', `Expansion one.')
+     =>
+     foo
+     =>Expansion one.
+     pushdef(`foo', `Expansion two.')
+     =>
+     foo
+     =>Expansion two.
+     define(`foo', `Second expansion two.')
+     =>
+     foo
+     =>Second expansion two.
+     undefine(`foo')
+     =>
+     foo
+     =>foo
+
+   Local variables within macros are made with `pushdef' and `popdef'.
+At the start of the macro a new definition is pushed, within the macro
+it is manipulated and at the end it is popped, revealing the former
+definition.
+
+   It is possible to temporarily redefine a builtin with `pushdef' and
+`defn'.
+
+
+File: m4.info,  Node: Indir,  Next: Builtin,  Prev: Pushdef,  Up: Definitions
+
+5.7 Indirect call of macros
+===========================
+
+Any macro can be called indirectly with `indir':
+
+ -- Builtin: indir (NAME, [ARGS...])
+     Results in a call to the macro NAME, which is passed the rest of
+     the arguments ARGS.  If NAME is not defined, an error message is
+     printed, and the expansion is void.
+
+     The macro `indir' is recognized only with parameters.
+
+   This can be used to call macros with computed or "invalid" names
+(`define' allows such names to be defined):
+
+     define(`$$internal$macro', `Internal macro (name `$0')')
+     =>
+     $$internal$macro
+     =>$$internal$macro
+     indir(`$$internal$macro')
+     =>Internal macro (name $$internal$macro)
+
+   The point is, here, that larger macro packages can have private
+macros defined, that will not be called by accident.  They can _only_ be
+called through the builtin `indir'.
+
+   One other point to observe is that argument collection occurs before
+`indir' invokes NAME, so if argument collection changes the value of
+NAME, that will be reflected in the final expansion.  This is different
+than the behavior when invoking macros directly, where the definition
+that was in effect before argument collection is used.
+
+     define(`f', `1')
+     =>
+     f(define(`f', `2'))
+     =>1
+     indir(`f', define(`f', `3'))
+     =>3
+     indir(`f', undefine(`f'))
+     error-->m4:stdin:4: undefined macro `f'
+     =>
+
+   When handed the result of `defn' (*note Defn::) as one of its
+arguments, `indir' defers to the invoked NAME for whether a token
+representing a builtin is recognized or flattened to the empty string.
+
+     indir(defn(`defn'), `divnum')
+     error-->m4:stdin:1: Warning: indir: invalid macro name ignored
+     =>
+     indir(`define', defn(`defn'), `divnum')
+     error-->m4:stdin:2: Warning: define: invalid macro name ignored
+     =>
+     indir(`define', `foo', defn(`divnum'))
+     =>
+     foo
+     =>0
+     indir(`divert', defn(`foo'))
+     error-->m4:stdin:5: empty string treated as 0 in builtin `divert'
+     =>
+
+
+File: m4.info,  Node: Builtin,  Prev: Indir,  Up: Definitions
+
+5.8 Indirect call of builtins
+=============================
+
+Builtin macros can be called indirectly with `builtin':
+
+ -- Builtin: builtin (NAME, [ARGS...])
+     Results in a call to the builtin NAME, which is passed the rest of
+     the arguments ARGS.  If NAME does not name a builtin, an error
+     message is printed, and the expansion is void.
+
+     The macro `builtin' is recognized only with parameters.
+
+   This can be used even if NAME has been given another definition that
+has covered the original, or been undefined so that no macro maps to
+the builtin.
+
+     pushdef(`define', `hidden')
+     =>
+     undefine(`undefine')
+     =>
+     define(`foo', `bar')
+     =>hidden
+     foo
+     =>foo
+     builtin(`define', `foo', defn(`divnum'))
+     =>
+     foo
+     =>0
+     builtin(`define', `foo', `BAR')
+     =>
+     foo
+     =>BAR
+     undefine(`foo')
+     =>undefine(foo)
+     foo
+     =>BAR
+     builtin(`undefine', `foo')
+     =>
+     foo
+     =>foo
+
+   The NAME argument only matches the original name of the builtin,
+even when the `--prefix-builtins' option (or `-P', *note Invoking m4:
+Operation modes.) is in effect.  This is different from `indir', which
+only tracks current macro names.
+
+   Note that `indir' and `builtin' can be used to invoke builtins
+without arguments, even when they normally require parameters to be
+recognized; but it will provoke a warning, and result in a void
+expansion.
+
+     builtin
+     =>builtin
+     builtin()
+     error-->m4:stdin:2: undefined builtin `'
+     =>
+     builtin(`builtin')
+     error-->m4:stdin:3: Warning: too few arguments to builtin `builtin'
+     =>
+     builtin(`builtin',)
+     error-->m4:stdin:4: undefined builtin `'
+     =>
+
+
+File: m4.info,  Node: Conditionals,  Next: Debugging,  Prev: Definitions,  Up: Top
+
+6 Conditionals, loops, and recursion
+************************************
+
+Macros, expanding to plain text, perhaps with arguments, are not quite
+enough.  We would like to have macros expand to different things, based
+on decisions taken at run-time.  For that, we need some kind of
+conditionals.  Also, we would like to have some kind of loop construct,
+so we could do something a number of times, or while some condition is
+true.
+
+* Menu:
+
+* Ifdef::                       Testing if a macro is defined
+* Ifelse::                      If-else construct, or multibranch
+* Shift::                       Recursion in `m4'
+* Forloop::                     Iteration by counting
+* Foreach::                     Iteration by list contents
+
+
+File: m4.info,  Node: Ifdef,  Next: Ifelse,  Up: Conditionals
+
+6.1 Testing if a macro is defined
+=================================
+
+There are two different builtin conditionals in `m4'.  The first is
+`ifdef':
+
+ -- Builtin: ifdef (NAME, STRING-1, [STRING-2])
+     If NAME is defined as a macro, `ifdef' expands to STRING-1,
+     otherwise to STRING-2.  If STRING-2 is omitted, it is taken to be
+     the empty string (according to the normal rules).
+
+     The macro `ifdef' is recognized only with parameters.
+
+     ifdef(`foo', ``foo' is defined', ``foo' is not defined')
+     =>foo is not defined
+     define(`foo', `')
+     =>
+     ifdef(`foo', ``foo' is defined', ``foo' is not defined')
+     =>foo is defined
+     ifdef(`no_such_macro', `yes', `no', `extra argument')
+     error-->m4:stdin:4: Warning: excess arguments to builtin `ifdef' ignored
+     =>no
+
+
+File: m4.info,  Node: Ifelse,  Next: Shift,  Prev: Ifdef,  Up: Conditionals
+
+6.2 If-else construct, or multibranch
+=====================================
+
+The other conditional, `ifelse', is much more powerful.  It can be used
+as a way to introduce a long comment, as an if-else construct, or as a
+multibranch, depending on the number of arguments supplied:
+
+ -- Builtin: ifelse (COMMENT)
+ -- Builtin: ifelse (STRING-1, STRING-2, EQUAL, [NOT-EQUAL])
+ -- Builtin: ifelse (STRING-1, STRING-2, EQUAL-1, STRING-3, STRING-4,
+          EQUAL-2, ...)
+     Used with only one argument, the `ifelse' simply discards it and
+     produces no output.
+
+     If called with three or four arguments, `ifelse' expands into
+     EQUAL, if STRING-1 and STRING-2 are equal (character for
+     character), otherwise it expands to NOT-EQUAL.  A final fifth
+     argument is ignored, after triggering a warning.
+
+     If called with six or more arguments, and STRING-1 and STRING-2
+     are equal, `ifelse' expands into EQUAL-1, otherwise the first
+     three arguments are discarded and the processing starts again.
+
+     The macro `ifelse' is recognized only with parameters.
+
+   Using only one argument is a common `m4' idiom for introducing a
+block comment, as an alternative to repeatedly using `dnl'.  This
+special usage is recognized by GNU `m4', so that in this case, the
+warning about missing arguments is never triggered.
+
+     ifelse(`some comments')
+     =>
+     ifelse(`foo', `bar')
+     error-->m4:stdin:2: Warning: too few arguments to builtin `ifelse'
+     =>
+
+   Using three or four arguments provides decision points.
+
+     ifelse(`foo', `bar', `true')
+     =>
+     ifelse(`foo', `foo', `true')
+     =>true
+     define(`foo', `bar')
+     =>
+     ifelse(foo, `bar', `true', `false')
+     =>true
+     ifelse(foo, `foo', `true', `false')
+     =>false
+
+   Notice how the first argument was used unquoted; it is common to
+compare the expansion of a macro with a string.  With this macro, you
+can now reproduce the behavior of many of the builtins, where the macro
+is recognized only with arguments.
+
+     define(`foo', `ifelse(`$#', `0', ``$0'', `arguments:$#')')
+     =>
+     foo
+     =>foo
+     foo()
+     =>arguments:1
+     foo(`a', `b', `c')
+     =>arguments:3
+
+   However, `ifelse' can take more than four arguments.  If given more
+than four arguments, `ifelse' works like a `case' or `switch' statement
+in traditional programming languages.  If STRING-1 and STRING-2 are
+equal, `ifelse' expands into EQUAL-1, otherwise the procedure is
+repeated with the first three arguments discarded.  This calls for an
+example:
+
+     ifelse(`foo', `bar', `third', `gnu', `gnats')
+     error-->m4:stdin:1: Warning: excess arguments to builtin `ifelse' ignored
+     =>gnu
+     ifelse(`foo', `bar', `third', `gnu', `gnats', `sixth')
+     =>
+     ifelse(`foo', `bar', `third', `gnu', `gnats', `sixth', `seventh')
+     =>seventh
+     ifelse(`foo', `bar', `3', `gnu', `gnats', `6', `7', `8')
+     error-->m4:stdin:4: Warning: excess arguments to builtin `ifelse' ignored
+     =>7
+
+   Naturally, the normal case will be slightly more advanced than these
+examples.  A common use of `ifelse' is in macros implementing loops of
+various kinds.
+
+
+File: m4.info,  Node: Shift,  Next: Forloop,  Prev: Ifelse,  Up: Conditionals
+
+6.3 Recursion in `m4'
+=====================
+
+There is no direct support for loops in `m4', but macros can be
+recursive.  There is no limit on the number of recursion levels, other
+than those enforced by your hardware and operating system.
+
+   Loops can be programmed using recursion and the conditionals
+described previously.
+
+   There is a builtin macro, `shift', which can, among other things, be
+used for iterating through the actual arguments to a macro:
+
+ -- Builtin: shift (ARG1, ...)
+     Takes any number of arguments, and expands to all its arguments
+     except ARG1, separated by commas, with each argument quoted.
+
+     The macro `shift' is recognized only with parameters.
+
+     shift
+     =>shift
+     shift(`bar')
+     =>
+     shift(`foo', `bar', `baz')
+     =>bar,baz
+
+   An example of the use of `shift' is this macro:
+
+ -- Composite: reverse (...)
+     Takes any number of arguments, and reverses their order.
+
+   It is implemented as:
+
+     define(`reverse', `ifelse(`$#', `0', , `$#', `1', ``$1'',
+                               `reverse(shift($@)), `$1'')')
+     =>
+     reverse
+     =>
+     reverse(`foo')
+     =>foo
+     reverse(`foo', `bar', `gnats', `and gnus')
+     =>and gnus, gnats, bar, foo
+
+   While not a very interesting macro, it does show how simple loops
+can be made with `shift', `ifelse' and recursion.  It also shows that
+`shift' is usually used with `$@'.  Sometimes, a recursive algorithm
+requires adding quotes to each element:
+
+ -- Composite: quote (...)
+ -- Composite: dquote (...)
+ -- Composite: dquote_elt (...)
+     Takes any number of arguments, and adds quoting.  With `quote',
+     only one level of quoting is added, effectively removing whitespace
+     after commas and turning multiple arguments into a single string.
+     With `dquote', two levels of quoting are added, one around each
+     element, and one around the list.  And with `dquote_elt', two
+     levels of quoting are added around each element.
+
+   An actual implementation of these three macros is distributed as
+`m4-1.4.8/examples/quote.m4' in this package.  First, let's examine
+their usage:
+
+     include(`quote.m4')
+     =>
+     -quote-dquote-dquote_elt-
+     =>----
+     -quote()-dquote()-dquote_elt()-
+     =>--`'-`'-
+     -quote(`1')-dquote(`1')-dquote_elt(`1')-
+     =>-1-`1'-`1'-
+     -quote(`1', `2')-dquote(`1', `2')-dquote_elt(`1', `2')-
+     =>-1,2-`1',`2'-`1',`2'-
+     define(`n', `$#')dnl
+     -n(quote(`1', `2'))-n(dquote(`1', `2'))-n(dquote_elt(`1', `2'))-
+     =>-1-1-2-
+     dquote(dquote_elt(`1', `2'))
+     =>``1'',``2''
+     dquote_elt(dquote(`1', `2'))
+     =>``1',`2''
+
+   The last two lines show that when given two arguments, `dquote'
+results in one string, while `dquote_elt' results in two.  Now, examine
+the implementation.  Note that `quote' and `dquote_elt' make decisions
+based on their number of arguments, so that when called without
+arguments, they result in nothing instead of a quoted empty string;
+this is so that it is possible to distinquish between no arguments and
+an empty first argument.  `dquote', on the other hand, results in a
+string no matter what, since it is still possible to tell whether it
+was invoked without arguments based on the resulting string.
+
+     undivert(`quote.m4')dnl
+     =>divert(`-1')
+     =># quote(args) - convert args to single-quoted string
+     =>define(`quote', `ifelse(`$#', `0', `', ``$*'')')
+     =># dquote(args) - convert args to quoted list of quoted strings
+     =>define(`dquote', ``$@'')
+     =># dquote_elt(args) - convert args to list of double-quoted strings
+     =>define(`dquote_elt', `ifelse(`$#', `0', `', `$#', `1', ```$1''',
+     =>                             ```$1'',$0(shift($@))')')
+     =>divert`'dnl
+
+
+File: m4.info,  Node: Forloop,  Next: Foreach,  Prev: Shift,  Up: Conditionals
+
+6.4 Iteration by counting
+=========================
+
+Here is an example of a loop macro that implements a simple for loop.
+
+ -- Composite: forloop (ITERATOR, START, END, TEXT)
+     Takes the name in ITERATOR, which must be a valid macro name, and
+     successively assign it each integer value from START to END,
+     inclusive.  For each assignment to ITERATOR, append TEXT to the
+     expansion of the `forloop'.  TEXT may refer to ITERATOR.  Any
+     definition of ITERATOR prior to this invocation is restored.
+
+   It can, for example, be used for simple counting:
+
+     include(`forloop.m4')
+     =>
+     forloop(`i', `1', `8', `i ')
+     =>1 2 3 4 5 6 7 8 
+
+   For-loops can be nested, like:
+
+     include(`forloop.m4')
+     =>
+     forloop(`i', `1', `4', `forloop(`j', `1', `8', ` (i, j)')
+     ')
+     => (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6) (1, 7) (1, 8)
+     => (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6) (2, 7) (2, 8)
+     => (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6) (3, 7) (3, 8)
+     => (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6) (4, 7) (4, 8)
+     =>
+
+   The implementation of the `forloop' macro is fairly straightforward.
+The `forloop' macro itself is simply a wrapper, which saves the
+previous definition of the first argument, calls the internal macro
+`_forloop', and re-establishes the saved definition of the first
+argument.
+
+   The macro `_forloop' expands the fourth argument once, and tests to
+see if the iterator has reached the final value.  If it has not
+finished, it increments the iterator (using the predefined macro
+`incr', *note Incr::), and recurses.
+
+   Here is an actual implementation of `forloop', distributed as
+`m4-1.4.8/examples/forloop.m4' in this package:
+
+     undivert(`forloop.m4')dnl
+     =>divert(`-1')
+     =># forloop(var, from, to, stmt) - simple version
+     =>define(`forloop', `pushdef(`$1', `$2')_forloop($@)popdef(`$1')')
+     =>define(`_forloop',
+     =>       `$4`'ifelse($1, `$3', `', `define(`$1', incr($1))$0($@)')')
+     =>divert`'dnl
+
+   Notice the careful use of quotes.  Certain macro arguments are left
+unquoted, each for its own reason.  Try to find out _why_ these
+arguments are left unquoted, and see what happens if they are quoted.
+(As presented, these two macros are useful but not very robust for
+general use.  They lack even basic error handling for cases like START
+less than END, END not numeric, or ITERATOR not being a macro name.
+See if you can improve these macros; or *note Answers: Improved
+forloop.).
+
+
+File: m4.info,  Node: Foreach,  Prev: Forloop,  Up: Conditionals
+
+6.5 Iteration by list contents
+==============================
+
+Here is an example of a loop macro that implements list iteration.
+
+ -- Composite: foreach (ITERATOR, PAREN-LIST, TEXT)
+ -- Composite: foreachq (ITERATOR, QUOTE-LIST, TEXT)
+     Takes the name in ITERATOR, which must be a valid macro name, and
+     successively assign it each value from PAREN-LIST or QUOTE-LIST.
+     In `foreach', PAREN-LIST is a comma-separated list of elements
+     contained in parentheses.  In `foreachq', QUOTE-LIST is a
+     comma-separated list of elements contained in a quoted string.
+     For each assignment to ITERATOR, append TEXT to the overall
+     expansion.  TEXT may refer to ITERATOR.  Any definition of
+     ITERATOR prior to this invocation is restored.
+
+   As an example, this displays each word in a list inside of a
+sentence, using an implementation of `foreach' distributed as
+`m4-1.4.8/examples/foreach.m4', and `foreachq' in
+`m4-1.4.8/examples/foreachq.m4'.
+
+     include(`foreach.m4')
+     =>
+     foreach(`x', (foo, bar, foobar), `Word was: x
+     ')dnl
+     =>Word was: foo
+     =>Word was: bar
+     =>Word was: foobar
+     include(`foreachq.m4')
+     =>
+     foreachq(`x', `foo, bar, foobar', `Word was: x
+     ')dnl
+     =>Word was: foo
+     =>Word was: bar
+     =>Word was: foobar
+
+   It is possible to be more complex; each element of the PAREN-LIST or
+QUOTE-LIST can itself be a list, to pass as further arguments to a
+helper macro.  This example generates a shell case statement:
+
+     include(`foreach.m4')
+     =>
+     define(`_case', `  $1)
+         $2=" $1";;
+     ')dnl
+     define(`_cat', `$1$2')dnl
+     case $`'1 in
+     =>case $1 in
+     foreach(`x', `(`(`a', `vara')', `(`b', `varb')', `(`c', `varc')')',
+             `_cat(`_case', x)')dnl
+     =>  a)
+     =>    vara=" a";;
+     =>  b)
+     =>    varb=" b";;
+     =>  c)
+     =>    varc=" c";;
+     esac
+     =>esac
+
+   The implementation of the `foreach' macro is a bit more involved; it
+is a wrapper around two helper macros.  First, `_arg1' is needed to
+grab the first element of a list.  Second, `_foreach' implements the
+recursion, successively walking through the original list.  Here is a
+simple implementation of `foreach':
+
+     undivert(`foreach.m4')dnl
+     =>divert(`-1')
+     =># foreach(x, (item_1, item_2, ..., item_n), stmt)
+     =>#   parenthesized list, simple version
+     =>define(`foreach', `pushdef(`$1')_foreach($@)popdef(`$1')')
+     =>define(`_arg1', `$1')
+     =>define(`_foreach', `ifelse(`$2', `()', `',
+     =>  `define(`$1', _arg1$2)$3`'$0(`$1', (shift$2), `$3')')')
+     =>divert`'dnl
+
+   Unfortunately, that implementation is not robust to macro names as
+list elements.  Each iteration of `_foreach' is stripping another layer
+of quotes, leading to erratic results if list elements are not already
+fully expanded.  The first cut at implementing `foreachq' takes this
+into account.  Also, when using quoted elements in a PAREN-LIST, the
+overall list must be quoted.  A QUOTE-LIST has the nice property of
+requiring fewer characters to create a list containing the same quoted
+elements.  To see the difference between the two macros, we attempt to
+pass double-quoted macro names in a list, expecting the macro name on
+output after one layer of quotes is removed during list iteration and
+the final layer removed during the final rescan:
+
+     define(`a', `1')define(`b', `2')define(`c', `3')
+     =>
+     include(`foreach.m4')
+     =>
+     include(`foreachq.m4')
+     =>
+     foreach(`x', `(``a'', ``(b'', ``c)'')', `x
+     ')
+     =>1
+     =>(2)1
+     =>
+     =>, x
+     =>)
+     foreachq(`x', ```a'', ``(b'', ``c)''', `x
+     ')dnl
+     =>a
+     =>(b
+     =>c)
+
+   Obviously, `foreachq' did a better job; here is its implementation:
+
+     undivert(`foreachq.m4')dnl
+     =>include(`quote.m4')dnl
+     =>divert(`-1')
+     =># foreachq(x, `item_1, item_2, ..., item_n', stmt)
+     =>#   quoted list, simple version
+     =>define(`foreachq', `pushdef(`$1')_foreachq($@)popdef(`$1')')
+     =>define(`_arg1', `$1')
+     =>define(`_foreachq', `ifelse(quote($2), `', `',
+     =>  `define(`$1', `_arg1($2)')$3`'$0(`$1', `shift($2)', `$3')')')
+     =>divert`'dnl
+
+   Notice that `_foreachq' had to use the helper macro `quote' defined
+earlier (*note Shift::), to ensure that the embedded `ifelse' call does
+not go haywire if a list element contains a comma.  Unfortunately, this
+implementation of `foreachq' has its own severe flaw.  Whereas the
+`foreach' implementation was linear, this macro is quadratic in the
+number of list elements, and is much more likely to trip up the limit
+set by the command line option `--nesting-limit' (or `-L', *note
+Invoking m4: Limits control.).  (It is possible to have robust
+iteration with linear behavior for either list style.  See if you can
+learn from the best elements of both of these implementations to create
+robust macros; or *note Answers: Improved foreach.).
+
+
+File: m4.info,  Node: Debugging,  Next: Input Control,  Prev: Conditionals,  Up: Top
+
+7 How to debug macros and input
+*******************************
+
+When writing macros for `m4', they often do not work as intended on the
+first try (as is the case with most programming languages).
+Fortunately, there is support for macro debugging in `m4'.
+
+* Menu:
+
+* Dumpdef::                     Displaying macro definitions
+* Trace::                       Tracing macro calls
+* Debug Levels::                Controlling debugging output
+* Debug Output::                Saving debugging output
+
+
+File: m4.info,  Node: Dumpdef,  Next: Trace,  Up: Debugging
+
+7.1 Displaying macro definitions
+================================
+
+If you want to see what a name expands into, you can use the builtin
+`dumpdef':
+
+ -- Builtin: dumpdef ([NAMES...])
+     Accepts any number of arguments.  If called without any arguments,
+     it displays the definitions of all known names, otherwise it
+     displays the definitions of the NAMES given.  The output is
+     printed to the current debug file (usually standard error), and is
+     sorted by name.  If an unknown name is encountered, a warning is
+     printed.
+
+     The expansion of `dumpdef' is void.
+
+     define(`foo', `Hello world.')
+     =>
+     dumpdef(`foo')
+     error-->foo: `Hello world.'
+     =>
+     dumpdef(`define')
+     error-->define: <define>
+     =>
+
+   The last example shows how builtin macros definitions are displayed.
+The definition that is dumped corresponds to what would occur if the
+macro were to be called at that point, even if other definitions are
+still live due to redefining a macro during argument collection.
+
+     pushdef(`f', ``$0'1')pushdef(`f', ``$0'2')
+     =>
+     f(popdef(`f')dumpdef(`f'))
+     error-->f: ``$0'1'
+     =>f2
+     f(popdef(`f')dumpdef(`f'))
+     error-->m4:stdin:3: undefined macro `f'
+     =>f1
+
+   *Note Debug Levels::, for information on controlling the details of
+the display.
+
+
+File: m4.info,  Node: Trace,  Next: Debug Levels,  Prev: Dumpdef,  Up: Debugging
+
+7.2 Tracing macro calls
+=======================
+
+It is possible to trace macro calls and expansions through the builtins
+`traceon' and `traceoff':
+
+ -- Builtin: traceon ([NAMES...])
+ -- Builtin: traceoff ([NAMES...])
+     When called without any arguments, `traceon' and `traceoff' will
+     turn tracing on and off, respectively, for all defined macros.
+
+     When called with arguments, only the macros listed in NAMES are
+     affected, whether or not they are currently defined.
+
+     The expansion of `traceon' and `traceoff' is void.
+
+   Whenever a traced macro is called and the arguments have been
+collected, the call is displayed.  If the expansion of the macro call
+is not void, the expansion can be displayed after the call.  The output
+is printed to the current debug file (defaulting to standard error,
+*note Debug Output::).
+
+     define(`foo', `Hello World.')
+     =>
+     define(`echo', `$@')
+     =>
+     traceon(`foo', `echo')
+     =>
+     foo
+     error-->m4trace: -1- foo -> `Hello World.'
+     =>Hello World.
+     echo(`gnus', `and gnats')
+     error-->m4trace: -1- echo(`gnus', `and gnats') -> ``gnus',`and gnats''
+     =>gnus,and gnats
+
+   The number between dashes is the depth of the expansion.  It is one
+most of the time, signifying an expansion at the outermost level, but it
+increases when macro arguments contain unquoted macro calls.  The
+maximum number that will appear between dashes is controlled by the
+option `--nesting-limit' (*note Invoking m4: Limits control.).
+
+   Tracing by name is an attribute that is preserved whether the macro
+is defined or not.  This allows the `-t' option to select macros to
+trace before those macros are defined.
+
+     traceoff(`foo')
+     =>
+     traceon(`foo')
+     =>
+     foo
+     =>foo
+     define(`foo', `bar')
+     =>
+     foo
+     error-->m4trace: -1- foo -> `bar'
+     =>bar
+     undefine(`foo')
+     =>
+     ifdef(`foo', `yes', `no')
+     =>no
+     indir(`foo')
+     error-->m4:stdin:8: undefined macro `foo'
+     =>
+     define(`foo', `blah')
+     =>
+     foo
+     error-->m4trace: -1- foo -> `blah'
+     =>blah
+     traceoff
+     =>
+     foo
+     =>blah
+
+   Tracing even works on builtins.  However, `defn' (*note Defn::) does
+not transfer tracing status.
+
+     traceon(`eval', `m4_divnum')
+     =>
+     define(`m4_eval', defn(`eval'))
+     =>
+     define(`m4_divnum', defn(`divnum'))
+     =>
+     eval(divnum)
+     error-->m4trace: -1- eval(`0') -> `0'
+     =>0
+     m4_eval(m4_divnum)
+     error-->m4trace: -2- m4_divnum -> `0'
+     =>0
+
+   *Note Debug Levels::, for information on controlling the details of
+the display.
+
+
+File: m4.info,  Node: Debug Levels,  Next: Debug Output,  Prev: Trace,  Up: Debugging
+
+7.3 Controlling debugging output
+================================
+
+The `-d' option to `m4' (*note Invoking m4: Debugging options.)
+controls the amount of details presented, when using the macros
+described in the preceding sections.
+
+   The FLAGS following the option can be one or more of the following:
+
+`a'
+     Show the actual arguments in each macro call.  This applies to all
+     macro calls if the `t' flag is used, otherwise only the macros
+     covered by calls of `traceon'.
+
+`c'
+     Show several trace lines for each macro call.  A line is shown
+     when the macro is seen, but before the arguments are collected; a
+     second line when the arguments have been collected and a third
+     line after the call has completed.
+
+`e'
+     Show the expansion of each macro call, if it is not void.  This
+     applies to all macro calls if the `t' flag is used, otherwise only
+     the macros covered by calls of `traceon'.
+
+`f'
+     Show the name of the current input file in each trace output line.
+
+`i'
+     Print a message each time the current input file is changed,
+     giving file name and input line number.
+
+`l'
+     Show the current input line number in each trace output line.
+
+`p'
+     Print a message when a named file is found through the path search
+     mechanism (*note Search Path::), giving the actual file name used.
+
+`q'
+     Quote actual arguments and macro expansions in the display with the
+     current quotes.
+
+`t'
+     Trace all macro calls made in this invocation of `m4'.
+
+`x'
+     Add a unique `macro call id' to each line of the trace output.
+     This is useful in connection with the `c' flag above.
+
+`V'
+     A shorthand for all of the above flags.
+
+   If no flags are specified with the `-d' option, the default is
+`aeq'.  The examples throughout this manual assume the default flags.
+
+   There is a builtin macro `debugmode', which allows on-the-fly
+control of the debugging output format:
+
+ -- Builtin: debugmode ([FLAGS])
+     The argument FLAGS should be a subset of the letters listed above.
+     As special cases, if the argument starts with a `+', the flags are
+     added to the current debug flags, and if it starts with a `-', they
+     are removed.  If no argument is present, all debugging flags are
+     cleared (as if no `-d' was given), and with an empty argument the
+     flags are reset to the default of `aeq'.
+
+     The expansion of `debugmode' is void.
+
+     define(`foo', `FOO')
+     =>
+     traceon(`foo')
+     =>
+     debugmode()
+     =>
+     foo
+     error-->m4trace: -1- foo -> `FOO'
+     =>FOO
+     debugmode
+     =>
+     foo
+     error-->m4trace: -1- foo
+     =>FOO
+     debugmode(`+l')
+     =>
+     foo
+     error-->m4trace:8: -1- foo
+     =>FOO
+
+
+File: m4.info,  Node: Debug Output,  Prev: Debug Levels,  Up: Debugging
+
+7.4 Saving debugging output
+===========================
+
+Debug and tracing output can be redirected to files using either the
+`--debugfile' option to `m4' (*note Invoking m4: Debugging options.),
+or with the builtin macro `debugfile':
+
+ -- Builtin: debugfile ([FILE])
+     Sends all further debug and trace output to FILE, opened in append
+     mode.  If FILE is the empty string, debug and trace output are
+     discarded.  If `debugfile' is called without any arguments, debug
+     and trace output are sent to standard error.  This does not affect
+     warnings, error messages, or `errprint' output, which are always
+     sent to standard error.  If FILE cannot be opened, the current
+     debug file is unchanged, and an error is issued.
+
+     The expansion of `debugfile' is void.
+
+     traceon(`divnum')
+     =>
+     divnum(`extra')
+     error-->m4:stdin:2: Warning: excess arguments to builtin `divnum' ignored
+     error-->m4trace: -1- divnum(`extra') -> `0'
+     =>0
+     debugfile()
+     =>
+     divnum(`extra')
+     error-->m4:stdin:4: Warning: excess arguments to builtin `divnum' ignored
+     =>0
+     debugfile
+     =>
+     divnum
+     error-->m4trace: -1- divnum -> `0'
+     =>0
+
+
+File: m4.info,  Node: Input Control,  Next: File Inclusion,  Prev: Debugging,  Up: Top
+
+8 Input control
+***************
+
+This chapter describes various builtin macros for controlling the input
+to `m4'.
+
+* Menu:
+
+* Dnl::                         Deleting whitespace in input
+* Changequote::                 Changing the quote characters
+* Changecom::                   Changing the comment delimiters
+* Changeword::                  Changing the lexical structure of words
+* M4wrap::                      Saving text until end of input
+
+
+File: m4.info,  Node: Dnl,  Next: Changequote,  Up: Input Control
+
+8.1 Deleting whitespace in input
+================================
+
+The builtin `dnl' stands for "Discard to Next Line":
+
+ -- Builtin: dnl
+     All characters, up to and including the next newline, are discarded
+     without performing any macro expansion.  A warning is issued if
+     the end of the file is encountered without a newline.
+
+     The expansion of `dnl' is void.
+
+   It is often used in connection with `define', to remove the newline
+that follows the call to `define'.  Thus
+
+     define(`foo', `Macro `foo'.')dnl A very simple macro, indeed.
+     foo
+     =>Macro foo.
+
+   The input up to and including the next newline is discarded, as
+opposed to the way comments are treated (*note Comments::).
+
+   Usually, `dnl' is immediately followed by an end of line or some
+other whitespace.  GNU `m4' will produce a warning diagnostic if `dnl'
+is followed by an open parenthesis.  In this case, `dnl' will collect
+and process all arguments, looking for a matching close parenthesis.
+All predictable side effects resulting from this collection will take
+place.  `dnl' will return no output.  The input following the matching
+close parenthesis up to and including the next newline, on whatever
+line containing it, will still be discarded.
+
+     dnl(`args are ignored, but side effects occur',
+     define(`foo', `like this')) while this text is ignored: undefine(`foo')
+     error-->m4:stdin:1: Warning: excess arguments to builtin `dnl' ignored
+     See how `foo' was defined, foo?
+     =>See how foo was defined, like this?
+
+   If the end of file is encountered without a newline character, a
+warning is issued and dnl stops consuming input.
+
+     m4wrap(`m4wrap(`2 hi
+     ')0 hi dnl 1 hi')
+     =>
+     define(`hi', `HI')
+     =>
+     ^D
+     error-->m4:stdin:1: Warning: end of file treated as newline
+     =>0 HI 2 HI
+
+
+File: m4.info,  Node: Changequote,  Next: Changecom,  Prev: Dnl,  Up: Input Control
+
+8.2 Changing the quote characters
+=================================
+
+The default quote delimiters can be changed with the builtin
+`changequote':
+
+ -- Builtin: changequote ([START = ``'], [END = `''])
+     This sets START as the new begin-quote delimiter and END as the
+     new end-quote delimiter.  If both arguments are missing, the
+     default quotes (``' and `'') are used.  If START is void, then
+     quoting is disabled.  Otherwise, if END is missing or void, the
+     default end-quote delimiter (`'') is used.  The quote delimiters
+     can be of any length.
+
+     The expansion of `changequote' is void.
+
+     changequote(`[', `]')
+     =>
+     define([foo], [Macro [foo].])
+     =>
+     foo
+     =>Macro foo.
+
+   The quotation strings can safely contain eight-bit characters.  If
+no single character is appropriate, START and END can be of any length.
+Other implementations cap the delimiter length to five characters, but
+GNU has no inherent limit.
+
+     changequote(`[[[', `]]]')
+     =>
+     define([[[foo]]], [[[Macro [[[[[foo]]]]].]]])
+     =>
+     foo
+     =>Macro [[foo]].
+
+   Calling `changequote' with START as the empty string will
+effectively disable the quoting mechanism, leaving no way to quote text.
+However, using an empty string is not portable, as some other
+implementations of `m4' revert to the default quoting, while others
+preserve the prior non-empty delimiter.  If START is not empty, then an
+empty END will use the default end-quote delimiter of `'', as
+otherwise, it would be impossible to end a quoted string.  Again, this
+is not portable, as some other `m4' implementations reuse START as the
+end-quote delimiter, while others preserve the previous non-empty
+value.  Omitting both arguments restores the default begin-quote and
+end-quote delimiters; fortunately this behavior is portable to all
+implementations of `m4'.
+
+     define(`foo', `Macro `FOO'.')
+     =>
+     changequote(`', `')
+     =>
+     foo
+     =>Macro `FOO'.
+     `foo'
+     =>`Macro `FOO'.'
+     changequote(`,)
+     =>
+     foo
+     =>Macro FOO.
+
+   There is no way in `m4' to quote a string containing an unmatched
+begin-quote, except using `changequote' to change the current quotes.
+
+   If the quotes should be changed from, say, `[' to `[[', temporary
+quote characters have to be defined.  To achieve this, two calls of
+`changequote' must be made, one for the temporary quotes and one for
+the new quotes.
+
+   Macros are recognized in preference to the begin-quote string, so if
+a prefix of START can be recognized as part of a potential macro name,
+the quoting mechanism is effectively disabled.  Unless you use
+`changeword' (*note Changeword::), this means that START should not
+begin with a letter, digit, or `_' (underscore).  However, even though
+quoted strings are not recognized, the quote characters can still be
+discerned in macro expansion and in trace output.
+
+     define(`echo', `$@')
+     =>
+     define(`hi', `HI')
+     =>
+     changequote(`q', `Q')
+     =>
+     q hi Q hi
+     =>q HI Q HI
+     echo(hi)
+     =>qHIQ
+     changequote
+     =>
+     changequote(`-', `EOF')
+     =>
+     - hi EOF hi
+     => hi  HI
+     changequote
+     =>
+     changequote(`1', `2')
+     =>
+     hi1hi2
+     =>hi1hi2
+     hi 1hi2
+     =>HI hi
+
+   Quotes are recognized in preference to argument collection.  In
+particular, if START is a single `(', then argument collection is
+effectively disabled.  For portability with other implementations, it
+is a good idea to avoid `(', `,', and `)' as the first character in
+START.
+
+     define(`echo', `$#:$@:')
+     =>
+     define(`hi', `HI')
+     =>
+     changequote(`(',`)')
+     =>
+     echo(hi)
+     =>0::hi
+     changequote
+     =>
+     changequote(`((', `))')
+     =>
+     echo(hi)
+     =>1:HI:
+     echo((hi))
+     =>0::hi
+     changequote
+     =>
+     changequote(`,', `)')
+     =>
+     echo(hi,hi)bye)
+     =>1:HIhibye:
+
+   If END is a prefix of START, the end-quote will be recognized in
+preference to a nested begin-quote.  In particular, changing the quotes
+to have the same string for START and END disables nesting of quotes.
+When quote nesting is disabled, it is impossible to double-quote
+strings across macro expansions, so using the same string is not done
+very often.
+
+     define(`hi', `HI')
+     =>
+     changequote(`""', `"')
+     =>
+     ""hi"""hi"
+     =>hihi
+     ""hi" ""hi"
+     =>hi hi
+     ""hi"" "hi"
+     =>hi" "HI"
+     changequote
+     =>
+     `hi`hi'hi'
+     =>hi`hi'hi
+     changequote(`"', `"')
+     =>
+     "hi"hi"hi"
+     =>hiHIhi
+
+   It is an error if the end of file occurs within a quoted string.
+
+     `hello world'
+     =>hello world
+     `dangling quote
+     ^D
+     error-->m4:stdin:2: ERROR: end of file in string
+
+
+File: m4.info,  Node: Changecom,  Next: Changeword,  Prev: Changequote,  Up: Input Control
+
+8.3 Changing the comment delimiters
+===================================
+
+The default comment delimiters can be changed with the builtin macro
+`changecom':
+
+ -- Builtin: changecom ([START], [END = `<NL>'])
+     This sets START as the new begin-comment delimiter and END as the
+     new end-comment delimiter.  If both arguments are missing, or
+     START is void, then comments are disabled.  Otherwise, if END is
+     missing or void, the default end-comment delimiter of newline is
+     used.  The comment delimiters can be of any length.
+
+     The expansion of `changecom' is void.
+
+     define(`comment', `COMMENT')
+     =>
+     # A normal comment
+     =># A normal comment
+     changecom(`/*', `*/')
+     =>
+     # Not a comment anymore
+     =># Not a COMMENT anymore
+     But: /* this is a comment now */ while this is not a comment
+     =>But: /* this is a comment now */ while this is not a COMMENT
+
+   Note how comments are copied to the output, much as if they were
+quoted strings.  If you want the text inside a comment expanded, quote
+the begin-comment delimiter.
+
+   Calling `changecom' without any arguments, or with START as the
+empty string, will effectively disable the commenting mechanism.  To
+restore the original comment start of `#', you must explicitly ask for
+it.  If START is not empty, then an empty END will use the default
+end-comment delimiter of newline, as otherwise, it would be impossible
+to end a comment.  However, this is not portable, as some other `m4'
+implementations preserve the previous non-empty delimiters instead.
+
+     define(`comment', `COMMENT')
+     =>
+     changecom
+     =>
+     # Not a comment anymore
+     =># Not a COMMENT anymore
+     changecom(`#', `')
+     =>
+     # comment again
+     =># comment again
+
+   The comment strings can safely contain eight-bit characters.  If no
+single character is appropriate, START and END can be of any length.
+Other implementations cap the delimiter length to five characters, but
+GNU has no inherent limit.
+
+   Comments are recognized in preference to macros.  However, this is
+not compatible with other implementations, where macros and even quoting
+takes precedence over comments, so it may change in a future release.
+For portability, this means that START should not begin with a letter,
+digit, or `_' (underscore), and that neither the start-quote nor the
+start-comment string should be a prefix of the other.
+
+     define(`hi', `HI')
+     =>
+     define(`hi1hi2', `hello')
+     =>
+     changecom(`q', `Q')
+     =>
+     q hi Q hi
+     =>q hi Q HI
+     changecom(`1', `2')
+     =>
+     hi1hi2
+     =>hello
+     hi 1hi2
+     =>HI 1hi2
+
+   Comments are recognized in preference to argument collection.  In
+particular, if START is a single `(', then argument collection is
+effectively disabled.  For portability with other implementations, it
+is a good idea to avoid `(', `,', and `)' as the first character in
+START.
+
+     define(`echo', `$#:$@:')
+     =>
+     define(`hi', `HI')
+     =>
+     changecom(`(',`)')
+     =>
+     echo(hi)
+     =>0::(hi)
+     changecom
+     =>
+     changecom(`((', `))')
+     =>
+     echo(hi)
+     =>1:HI:
+     echo((hi))
+     =>0::((hi))
+     changecom(`,', `)')
+     =>
+     echo(hi,hi)bye)
+     =>1:HI,hi)bye:
+
+   It is an error if the end of file occurs within a comment.
+
+     changecom(`/*', `*/')
+     =>
+     /*dangling comment
+     ^D
+     error-->m4:stdin:2: ERROR: end of file in comment
+
+
+File: m4.info,  Node: Changeword,  Next: M4wrap,  Prev: Changecom,  Up: Input Control
+
+8.4 Changing the lexical structure of words
+===========================================
+
+     The macro `changeword' and all associated functionality is
+     experimental.  It is only available if the `--enable-changeword'
+     option was given to `configure', at GNU `m4' installation time.
+     The functionality will go away in the future, to be replaced by
+     other new features that are more efficient at providing the same
+     capabilities.  _Do not rely on it_.  Please direct your comments
+     about it the same way you would do for bugs.
+
+   A file being processed by `m4' is split into quoted strings, words
+(potential macro names) and simple tokens (any other single character).
+Initially a word is defined by the following regular expression:
+
+     [_a-zA-Z][_a-zA-Z0-9]*
+
+   Using `changeword', you can change this regular expression:
+
+ -- Optional builtin: changeword (REGEX)
+     Changes the regular expression for recognizing macro names to be
+     REGEX.  If REGEX is empty, use `[_a-zA-Z][_a-zA-Z0-9]*'.  REGEX
+     must obey the constraint that every prefix of the desired final
+     pattern is also accepted by the regular expression.  If REGEX
+     contains grouping parentheses, the macro invoked is the portion
+     that matched the first group, rather than the entire matching
+     string.
+
+     The expansion of `changeword' is void.  The macro `changeword' is
+     recognized only with parameters.
+
+   Relaxing the lexical rules of `m4' might be useful (for example) if
+you wanted to apply translations to a file of numbers:
+
+     ifdef(`changeword', `', `errprint(` skipping: no changeword support
+     ')m4exit(`77')')dnl
+     changeword(`[_a-zA-Z0-9]+')
+     =>
+     define(`1', `0')1
+     =>0
+
+   Tightening the lexical rules is less useful, because it will
+generally make some of the builtins unavailable.  You could use it to
+prevent accidental call of builtins, for example:
+
+     ifdef(`changeword', `', `errprint(` skipping: no changeword support
+     ')m4exit(`77')')dnl
+     define(`_indir', defn(`indir'))
+     =>
+     changeword(`_[_a-zA-Z0-9]*')
+     =>
+     esyscmd(`foo')
+     =>esyscmd(foo)
+     _indir(`esyscmd', `echo hi')
+     =>hi
+     =>
+
+   Because `m4' constructs its words a character at a time, there is a
+restriction on the regular expressions that may be passed to
+`changeword'.  This is that if your regular expression accepts `foo',
+it must also accept `f' and `fo'.
+
+     ifdef(`changeword', `', `errprint(` skipping: no changeword support
+     ')m4exit(`77')')dnl
+     define(`foo
+     ', `bar
+     ')
+     =>
+     dnl This example wants to recognize changeword, dnl, and `foo\n'.
+     dnl First, we check that our regexp will match.
+     regexp(`changeword', `[cd][a-z]*\|foo[
+     ]')
+     =>0
+     regexp(`foo
+     ', `[cd][a-z]*\|foo[
+     ]')
+     =>0
+     regexp(`f', `[cd][a-z]*\|foo[
+     ]')
+     =>-1
+     foo
+     =>foo
+     changeword(`[cd][a-z]*\|foo[
+     ]')
+     =>
+     dnl Even though `foo\n' matches, we forgot to allow `f'.
+     foo
+     =>foo
+     changeword(`[cd][a-z]*\|fo*[
+     ]?')
+     =>
+     dnl Now we can call `foo\n'.
+     foo
+     =>bar
+
+   `changeword' has another function.  If the regular expression
+supplied contains any grouped subexpressions, then text outside the
+first of these is discarded before symbol lookup.  So:
+
+     ifdef(`changeword', `', `errprint(` skipping: no changeword support
+     ')m4exit(`77')')dnl
+     ifdef(`__unix__', ,
+           `errprint(` skipping: syscmd does not have unix semantics
+     ')m4exit(`77')')dnl
+     changecom(`/*', `*/')dnl
+     define(`foo', `bar')dnl
+     changeword(`#\([_a-zA-Z0-9]*\)')
+     =>
+     #esyscmd(`echo foo \#foo')
+     =>foo bar
+     =>
+
+   `m4' now requires a `#' mark at the beginning of every macro
+invocation, so one can use `m4' to preprocess plain text without losing
+various words like `divert'.
+
+   In `m4', macro substitution is based on text, while in TeX, it is
+based on tokens.  `changeword' can throw this difference into relief.
+For example, here is the same idea represented in TeX and `m4'.  First,
+the TeX version:
+
+     \def\a{\message{Hello}}
+     \catcode`\@=0
+     \catcode`\\=12
+     @a
+     @bye
+     =>Hello
+
+Then, the `m4' version:
+
+     ifdef(`changeword', `', `errprint(` skipping: no changeword support
+     ')m4exit(`77')')dnl
+     define(`a', `errprint(`Hello')')dnl
+     changeword(`@\([_a-zA-Z0-9]*\)')
+     =>
+     @a
+     =>errprint(Hello)
+
+   In the TeX example, the first line defines a macro `a' to print the
+message `Hello'.  The second line defines <@> to be usable instead of
+<\> as an escape character.  The third line defines <\> to be a normal
+printing character, not an escape.  The fourth line invokes the macro
+`a'.  So, when TeX is run on this file, it displays the message `Hello'.
+
+   When the `m4' example is passed through `m4', it outputs
+`errprint(Hello)'.  The reason for this is that TeX does lexical
+analysis of macro definition when the macro is _defined_.  `m4' just
+stores the text, postponing the lexical analysis until the macro is
+_used_.
+
+   You should note that using `changeword' will slow `m4' down by a
+factor of about seven, once it is changed to something other than the
+default regular expression.  You can invoke `changeword' with the empty
+string to restore the default word definition, and regain the parsing
+speed.
+
+
+File: m4.info,  Node: M4wrap,  Prev: Changeword,  Up: Input Control
+
+8.5 Saving text until end of input
+==================================
+
+It is possible to `save' some text until the end of the normal input has
+been seen.  Text can be saved, to be read again by `m4' when the normal
+input has been exhausted.  This feature is normally used to initiate
+cleanup actions before normal exit, e.g., deleting temporary files.
+
+   To save input text, use the builtin `m4wrap':
+
+ -- Builtin: m4wrap (STRING, ...)
+     Stores STRING in a safe place, to be reread when end of input is
+     reached.  As a GNU extension, additional arguments are
+     concatenated with a space to the STRING.
+
+     The expansion of `m4wrap' is void.  The macro `m4wrap' is
+     recognized only with parameters.
+
+     define(`cleanup', `This is the `cleanup' action.
+     ')
+     =>
+     m4wrap(`cleanup')
+     =>
+     This is the first and last normal input line.
+     =>This is the first and last normal input line.
+     ^D
+     =>This is the cleanup action.
+
+   The saved input is only reread when the end of normal input is seen,
+and not if `m4exit' is used to exit `m4'.
+
+   It is safe to call `m4wrap' from saved text, but then the order in
+which the saved text is reread is undefined.  If `m4wrap' is not used
+recursively, the saved pieces of text are reread in the opposite order
+in which they were saved (LIFO--last in, first out).  However, this
+behavior is likely to change in a future release, to match POSIX, so
+you should not depend on this order.
+
+   Here is an example of implementing a factorial function using
+`m4wrap':
+
+     define(`f', `ifelse(`$1', `0', `Answer: 0!=1
+     ', eval(`$1>1'), `0', `Answer: $2$1=eval(`$2$1')
+     ', `m4wrap(`f(decr(`$1'), `$2$1*')')')')
+     =>
+     f(`10')
+     =>
+     ^D
+     =>Answer: 10*9*8*7*6*5*4*3*2*1=3628800
+
+   Invocations of `m4wrap' at the same recursion level are concatenated
+and rescanned as usual:
+
+     define(`aa', `AA
+     ')
+     =>
+     m4wrap(`a')m4wrap(`a')
+     =>
+     ^D
+     =>AA
+
+however, the transition between recursion levels behaves like an end of
+file condition between two input files.
+
+     m4wrap(`m4wrap(`)')len(abc')
+     =>
+     ^D
+     error-->m4:stdin:1: ERROR: end of file in argument list
+
+
+File: m4.info,  Node: File Inclusion,  Next: Diversions,  Prev: Input Control,  Up: Top
+
+9 File inclusion
+****************
+
+`m4' allows you to include named files at any point in the input.
+
+* Menu:
+
+* Include::                     Including named files
+* Search Path::                 Searching for include files
+
+
+File: m4.info,  Node: Include,  Next: Search Path,  Up: File Inclusion
+
+9.1 Including named files
+=========================
+
+There are two builtin macros in `m4' for including files:
+
+ -- Builtin: include (FILE)
+ -- Builtin: sinclude (FILE)
+     Both macros cause the file named FILE to be read by `m4'.  When
+     the end of the file is reached, input is resumed from the previous
+     input file.
+
+     The expansion of `include' and `sinclude' is therefore the
+     contents of FILE.
+
+     If FILE does not exist (or cannot be read), the expansion is void,
+     and `include' will fail with an error while `sinclude' is silent.
+     The empty string counts as a file that does not exist.
+
+     The macros `include' and `sinclude' are recognized only with
+     parameters.
+
+     include(`none')
+     error-->m4:stdin:1: cannot open `none': No such file or directory
+     =>
+     include()
+     error-->m4:stdin:2: cannot open `': No such file or directory
+     =>
+     sinclude(`none')
+     =>
+     sinclude()
+     =>
+
+   The rest of this section assumes that `m4' is invoked with the `-I'
+option (*note Invoking m4: Preprocessor features.)  pointing to the
+`m4-1.4.8/examples' directory shipped as part of the GNU `m4' package.
+The file `m4-1.4.8/examples/incl.m4' in the distribution contains the
+lines:
+
+     Include file start
+     foo
+     Include file end
+
+   Normally file inclusion is used to insert the contents of a file
+into the input stream.  The contents of the file will be read by `m4'
+and macro calls in the file will be expanded:
+
+     define(`foo', `FOO')
+     =>
+     include(`incl.m4')
+     =>Include file start
+     =>FOO
+     =>Include file end
+     =>
+
+   The fact that `include' and `sinclude' expand to the contents of the
+file can be used to define macros that operate on entire files.  Here
+is an example, which defines `bar' to expand to the contents of
+`incl.m4':
+
+     define(`bar', include(`incl.m4'))
+     =>
+     This is `bar':  >>bar<<
+     =>This is bar:  >>Include file start
+     =>foo
+     =>Include file end
+     =><<
+
+   This use of `include' is not trivial, though, as files can contain
+quotes, commas, and parentheses, which can interfere with the way the
+`m4' parser works.  GNU `m4' seamlessly concatenates the file contents
+with the next character, even if the included file ended in the middle
+of a comment, string, or macro call.  These conditions are only treated
+as end of file errors if specified as input files on the command line.
+
+   In GNU `m4', an alternative method of reading files is using
+`undivert' (*note Undivert::) on a named file.
+
+
+File: m4.info,  Node: Search Path,  Prev: Include,  Up: File Inclusion
+
+9.2 Searching for include files
+===============================
+
+GNU `m4' allows included files to be found in other directories than
+the current working directory.
+
+   If the `--prepend-include' or `-B' command-line option was provided
+(*note Invoking m4: Preprocessor features.), those directories are
+searched first, in reverse order that those options were listed on the
+command line.  Then `m4' looks in the current working directory.  Next
+comes the directories specified with the `--include' or `-I' option, in
+the order found on the command line.  Finally, if the `M4PATH'
+environment variable is set, it is expected to contain a
+colon-separated list of directories, which will be searched in order.
+
+   If the automatic search for include-files causes trouble, the `p'
+debug flag (*note Debug Levels::) can help isolate the problem.
+
+
+File: m4.info,  Node: Diversions,  Next: Text handling,  Prev: File Inclusion,  Up: Top
+
+10 Diverting and undiverting output
+***********************************
+
+Diversions are a way of temporarily saving output.  The output of `m4'
+can at any time be diverted to a temporary file, and be reinserted into
+the output stream, "undiverted", again at a later time.
+
+   Numbered diversions are counted from 0 upwards, diversion number 0
+being the normal output stream.  The number of simultaneous diversions
+is limited mainly by the memory used to describe them, because GNU `m4'
+tries to keep diversions in memory.  However, there is a limit to the
+overall memory usable by all diversions taken altogether (512K,
+currently).  When this maximum is about to be exceeded, a temporary
+file is opened to receive the contents of the biggest diversion still
+in memory, freeing this memory for other diversions.  When creating the
+temporary file, `m4' honors the value of the environment variable
+`TMPDIR', and falls back to `/tmp'.  So, it is theoretically possible
+that the number and aggregate size of diversions is limited only by
+available disk space.
+
+   Diversions make it possible to generate output in a different order
+than the input was read.  It is possible to implement topological
+sorting dependencies.  For example, GNU Autoconf makes use of
+diversions under the hood to ensure that the expansion of a prerequisite
+macro appears in the output prior to the expansion of a dependent macro,
+regardless of which order the two macros were invoked in the user's
+input file.
+
+* Menu:
+
+* Divert::                      Diverting output
+* Undivert::                    Undiverting output
+* Divnum::                      Diversion numbers
+* Cleardivert::                 Discarding diverted text
+
+
+File: m4.info,  Node: Divert,  Next: Undivert,  Up: Diversions
+
+10.1 Diverting output
+=====================
+
+Output is diverted using `divert':
+
+ -- Builtin: divert ([NUMBER = `0'])
+     The current diversion is changed to NUMBER.  If NUMBER is left out
+     or empty, it is assumed to be zero.  If NUMBER cannot be parsed,
+     the diversion is unchanged.
+
+     The expansion of `divert' is void.
+
+   When all the `m4' input will have been processed, all existing
+diversions are automatically undiverted, in numerical order.
+
+     divert(`1')
+     This text is diverted.
+     divert
+     =>
+     This text is not diverted.
+     =>This text is not diverted.
+     ^D
+     =>
+     =>This text is diverted.
+
+   Several calls of `divert' with the same argument do not overwrite
+the previous diverted text, but append to it.  Diversions are printed
+after any wrapped text is expanded.
+
+     define(`text', `TEXT')
+     =>
+     divert(`1')`diverted text.'
+     divert
+     =>
+     m4wrap(`Wrapped text preceeds ')
+     =>
+     ^D
+     =>Wrapped TEXT preceeds diverted text.
+
+   If output is diverted to a negative diversion, it is simply
+discarded.  This can be used to suppress unwanted output.  A common
+example of unwanted output is the trailing newlines after macro
+definitions.  Here is a common programming idiom in `m4' for avoiding
+them.
+
+     divert(`-1')
+     define(`foo', `Macro `foo'.')
+     define(`bar', `Macro `bar'.')
+     divert
+     =>
+
+   Traditional implementations only supported ten diversions.  But as a
+GNU extension, diversion numbers can be as large as positive integers
+will allow, rather than treating a multi-digit diversion number as a
+request to discard text.
+
+     divert(eval(`1<<28'))world
+     divert(`2')hello
+     ^D
+     =>hello
+     =>world
+
+   Note that `divert' is an English word, but also an active macro
+without arguments.  When processing plain text, the word might appear in
+normal text and be unintentionally swallowed as a macro invocation.  One
+way to avoid this is to use the `-P' option to rename all builtins
+(*note Invoking m4: Operation modes.).  Another is to write a wrapper
+that requires a parameter to be recognized.
+
+     We decided to divert the stream for irrigation.
+     =>We decided to  the stream for irrigation.
+     define(`divert', `ifelse(`$#', `0', ``$0'', `builtin(`$0', $@)')')
+     =>
+     divert(`-1')
+     Ignored text.
+     divert(`0')
+     =>
+     We decided to divert the stream for irrigation.
+     =>We decided to divert the stream for irrigation.
+
+
+File: m4.info,  Node: Undivert,  Next: Divnum,  Prev: Divert,  Up: Diversions
+
+10.2 Undiverting output
+=======================
+
+Diverted text can be undiverted explicitly using the builtin `undivert':
+
+ -- Builtin: undivert ([DIVERSIONS...])
+     Undiverts the numeric DIVERSIONS given by the arguments, in the
+     order given.  If no arguments are supplied, all diversions are
+     undiverted, in numerical order.
+
+     As a GNU extension, DIVERSIONS may contain non-numeric strings,
+     which are treated as the names of files to copy into the output
+     without expansion.  A warning is issued if a file could not be
+     opened.
+
+     The expansion of `undivert' is void.
+
+     divert(`1')
+     This text is diverted.
+     divert
+     =>
+     This text is not diverted.
+     =>This text is not diverted.
+     undivert(`1')
+     =>
+     =>This text is diverted.
+     =>
+
+   Notice the last two blank lines.  One of them comes from the newline
+following `undivert', the other from the newline that followed the
+`divert'!  A diversion often starts with a blank line like this.
+
+   When diverted text is undiverted, it is _not_ reread by `m4', but
+rather copied directly to the current output, and it is therefore not
+an error to undivert into a diversion.  Undiverting the empty string is
+the same as specifying diversion 0; in either case nothing happens
+since the output has already been flushed.
+
+     divert(`1')diverted text
+     divert
+     =>
+     undivert()
+     =>
+     undivert(`0')
+     =>
+     undivert
+     =>diverted text
+     =>
+
+   When a diversion has been undiverted, the diverted text is discarded,
+and it is not possible to bring back diverted text more than once.
+
+     divert(`1')
+     This text is diverted first.
+     divert(`0')undivert(`1')dnl
+     =>
+     =>This text is diverted first.
+     undivert(`1')
+     =>
+     divert(`1')
+     This text is also diverted but not appended.
+     divert(`0')undivert(`1')dnl
+     =>
+     =>This text is also diverted but not appended.
+
+   Attempts to undivert the current diversion are silently ignored.
+Thus, when the current diversion is not 0, the current diversion does
+not get rearranged among the other diversions.
+
+     divert(`1')one
+     divert(`2')two
+     divert(`3')three
+     divert(`2')undivert`'dnl
+     divert`'undivert`'dnl
+     =>two
+     =>one
+     =>three
+
+   GNU `m4' allows named files to be undiverted.  Given a non-numeric
+argument, the contents of the file named will be copied, uninterpreted,
+to the current output.  This complements the builtin `include' (*note
+Include::).  To illustrate the difference, the file
+`m4-1.4.8/examples/foo' contains the word `bar':
+
+     define(`bar', `BAR')
+     =>
+     undivert(`foo')
+     =>bar
+     =>
+     include(`foo')
+     =>BAR
+     =>
+
+   If the file is not found (or cannot be read), an error message is
+issued, and the expansion is void.
+
+
+File: m4.info,  Node: Divnum,  Next: Cleardivert,  Prev: Undivert,  Up: Diversions
+
+10.3 Diversion numbers
+======================
+
+The current diversion is tracked by the builtin `divnum':
+
+ -- Builtin: divnum
+     Expands to the number of the current diversion.
+
+     Initial divnum
+     =>Initial 0
+     divert(`1')
+     Diversion one: divnum
+     divert(`2')
+     Diversion two: divnum
+     ^D
+     =>
+     =>Diversion one: 1
+     =>
+     =>Diversion two: 2
+
+
+File: m4.info,  Node: Cleardivert,  Prev: Divnum,  Up: Diversions
+
+10.4 Discarding diverted text
+=============================
+
+Often it is not known, when output is diverted, whether the diverted
+text is actually needed.  Since all non-empty diversion are brought back
+on the main output stream when the end of input is seen, a method of
+discarding a diversion is needed.  If all diversions should be
+discarded, the easiest is to end the input to `m4' with `divert(`-1')'
+followed by an explicit `undivert':
+
+     divert(`1')
+     Diversion one: divnum
+     divert(`2')
+     Diversion two: divnum
+     divert(`-1')
+     undivert
+     ^D
+
+No output is produced at all.
+
+   Clearing selected diversions can be done with the following macro:
+
+ -- Composite: cleardivert ([DIVERSIONS...])
+     Discard the contents of each of the listed numeric DIVERSIONS.
+
+     define(`cleardivert',
+     `pushdef(`_n', divnum)divert(`-1')undivert($@)divert(_n)popdef(`_n')')
+     =>
+
+   It is called just like `undivert', but the effect is to clear the
+diversions, given by the arguments.  (This macro has a nasty bug!  You
+should try to see if you can find it and correct it; or *note Answers:
+Improved cleardivert.).
+
+
+File: m4.info,  Node: Text handling,  Next: Arithmetic,  Prev: Diversions,  Up: Top
+
+11 Macros for text handling
+***************************
+
+There are a number of builtins in `m4' for manipulating text in various
+ways, extracting substrings, searching, substituting, and so on.
+
+* Menu:
+
+* Len::                         Calculating length of strings
+* Index macro::                 Searching for substrings
+* Regexp::                      Searching for regular expressions
+* Substr::                      Extracting substrings
+* Translit::                    Translating characters
+* Patsubst::                    Substituting text by regular expression
+* Format::                      Formatting strings (printf-like)
+
+
+File: m4.info,  Node: Len,  Next: Index macro,  Up: Text handling
+
+11.1 Calculating length of strings
+==================================
+
+The length of a string can be calculated by `len':
+
+ -- Builtin: len (STRING)
+     Expands to the length of STRING, as a decimal number.
+
+     The macro `len' is recognized only with parameters.
+
+     len()
+     =>0
+     len(`abcdef')
+     =>6
+
+
+File: m4.info,  Node: Index macro,  Next: Regexp,  Prev: Len,  Up: Text handling
+
+11.2 Searching for substrings
+=============================
+
+Searching for substrings is done with `index':
+
+ -- Builtin: index (STRING, SUBSTRING)
+     Expands to the index of the first occurrence of SUBSTRING in
+     STRING.  The first character in STRING has index 0.  If SUBSTRING
+     does not occur in STRING, `index' expands to `-1'.
+
+     The macro `index' is recognized only with parameters.
+
+     index(`gnus, gnats, and armadillos', `nat')
+     =>7
+     index(`gnus, gnats, and armadillos', `dag')
+     =>-1
+
+   Omitting SUBSTRING evokes a warning, but still produces output.
+
+     index(`abc')
+     error-->m4:stdin:1: Warning: too few arguments to builtin `index'
+     =>0
+
+
+File: m4.info,  Node: Regexp,  Next: Substr,  Prev: Index macro,  Up: Text handling
+
+11.3 Searching for regular expressions
+======================================
+
+Searching for regular expressions is done with the builtin `regexp':
+
+ -- Builtin: regexp (STRING, REGEXP, [REPLACEMENT])
+     Searches for REGEXP in STRING.  The syntax for regular expressions
+     is the same as in GNU Emacs.  *Note Syntax of Regular Expressions:
+     (emacs)Regexps.
+
+     If REPLACEMENT is omitted, `regexp' expands to the index of the
+     first match of REGEXP in STRING.  If REGEXP does not match
+     anywhere in STRING, it expands to -1.
+
+     If REPLACEMENT is supplied, and there was a match, `regexp'
+     changes the expansion to this argument, with `\N' substituted by
+     the text matched by the Nth parenthesized sub-expression of
+     REGEXP, up to nine sub-expressions.  The escape `\&' is replaced
+     by the text of the entire regular expression matched.  For all
+     other characters, `\' treats the next character literally.  A
+     warning is issued if there were fewer sub-expressions than the
+     `\N' requested, or if there is a trailing `\'.  If there was no
+     match, `regexp' expands to the empty string.
+
+     The macro `regexp' is recognized only with parameters.
+
+     regexp(`GNUs not Unix', `\<[a-z]\w+')
+     =>5
+     regexp(`GNUs not Unix', `\<Q\w*')
+     =>-1
+     regexp(`GNUs not Unix', `\w\(\w+\)$', `*** \& *** \1 ***')
+     =>*** Unix *** nix ***
+     regexp(`GNUs not Unix', `\<Q\w*', `*** \& *** \1 ***')
+     =>
+
+   Here are some more examples on the handling of backslash:
+
+     regexp(`abc', `\(b\)', `\\\10\a')
+     =>\b0a
+     regexp(`abc', `b', `\1\')
+     error-->m4:stdin:2: Warning: sub-expression 1 not present
+     error-->m4:stdin:2: Warning: trailing \ ignored in replacement
+     =>
+     regexp(`abc', `\(\(d\)?\)\(c\)', `\1\2\3\4\5\6')
+     error-->m4:stdin:3: Warning: sub-expression 4 not present
+     error-->m4:stdin:3: Warning: sub-expression 5 not present
+     error-->m4:stdin:3: Warning: sub-expression 6 not present
+     =>c
+
+   Omitting REGEXP evokes a warning, but still produces output.
+
+     regexp(`abc')
+     error-->m4:stdin:1: Warning: too few arguments to builtin `regexp'
+     =>0
+
+
+File: m4.info,  Node: Substr,  Next: Translit,  Prev: Regexp,  Up: Text handling
+
+11.4 Extracting substrings
+==========================
+
+Substrings are extracted with `substr':
+
+ -- Builtin: substr (STRING, FROM, [LENGTH])
+     Expands to the substring of STRING, which starts at index FROM,
+     and extends for LENGTH characters, or to the end of STRING, if
+     LENGTH is omitted.  The starting index of a string is always 0.
+     The expansion is empty if there is an error parsing FROM or
+     LENGTH, if FROM is beyond the end of STRING, or if LENGTH is
+     negative.
+
+     The macro `substr' is recognized only with parameters.
+
+     substr(`gnus, gnats, and armadillos', `6')
+     =>gnats, and armadillos
+     substr(`gnus, gnats, and armadillos', `6', `5')
+     =>gnats
+
+   Omitting FROM evokes a warning, but still produces output.
+
+     substr(`abc')
+     error-->m4:stdin:1: Warning: too few arguments to builtin `substr'
+     =>abc
+     substr(`abc',)
+     error-->m4:stdin:2: empty string treated as 0 in builtin `substr'
+     =>abc
+
+
+File: m4.info,  Node: Translit,  Next: Patsubst,  Prev: Substr,  Up: Text handling
+
+11.5 Translating characters
+===========================
+
+Character translation is done with `translit':
+
+ -- Builtin: translit (STRING, CHARS, [REPLACEMENT])
+     Expands to STRING, with each character that occurs in CHARS
+     translated into the character from REPLACEMENT with the same index.
+
+     If REPLACEMENT is shorter than CHARS, the excess characters of
+     CHARS are deleted from the expansion; if CHARS is shorter, the
+     excess characters in REPLACEMENT are silently ignored.  If
+     REPLACEMENT is omitted, all characters in STRING that are present
+     in CHARS are deleted from the expansion.  If a character appears
+     more than once in CHARS, only the first instance is used in making
+     the translation.  Only a single translation pass is made, even if
+     characters in REPLACEMENT also appear in CHARS.
+
+     As a GNU extension, both CHARS and REPLACEMENT can contain
+     character-ranges, e.g., `a-z' (meaning all lowercase letters) or
+     `0-9' (meaning all digits).  To include a dash `-' in CHARS or
+     REPLACEMENT, place it first or last in the entire string, or as
+     the last character of a range.  Back-to-back ranges can share a
+     common endpoint.  It is not an error for the last character in the
+     range to be `larger' than the first.  In that case, the range runs
+     backwards, i.e., `9-0' means the string `9876543210'.  The
+     expansion of a range is dependent on the underlying encoding of
+     characters, so using ranges is not always portable between
+     machines.
+
+     The macro `translit' is recognized only with parameters.
+
+     translit(`GNUs not Unix', `A-Z')
+     =>s not nix
+     translit(`GNUs not Unix', `a-z', `A-Z')
+     =>GNUS NOT UNIX
+     translit(`GNUs not Unix', `A-Z', `z-a')
+     =>tmfs not fnix
+     translit(`+,-12345', `+--1-5', `<;>a-c-a')
+     =><;>abcba
+     translit(`abcdef', `aabdef', `bcged')
+     =>bgced
+
+   In the ASCII encoding, the first example deletes all uppercase
+letters, the second converts lowercase to uppercase, and the third
+`mirrors' all uppercase letters, while converting them to lowercase.
+The two first cases are by far the most common, even though they are not
+portable to EBCDIC or other encodings.  The fourth example shows a
+range ending in `-', as well as back-to-back ranges.  The final example
+shows that `a' is mapped to `b', not `c'; the resulting `b' is not
+further remapped to `g'; the `d' and `e' are swapped, and the `f' is
+discarded.
+
+   Omitting CHARS evokes a warning, but still produces output.
+
+     translit(`abc')
+     error-->m4:stdin:1: Warning: too few arguments to builtin `translit'
+     =>abc
+
+
+File: m4.info,  Node: Patsubst,  Next: Format,  Prev: Translit,  Up: Text handling
+
+11.6 Substituting text by regular expression
+============================================
+
+Global substitution in a string is done by `patsubst':
+
+ -- Builtin: patsubst (STRING, REGEXP, [REPLACEMENT])
+     Searches STRING for matches of REGEXP, and substitutes REPLACEMENT
+     for each match.  The syntax for regular expressions is the same as
+     in GNU Emacs (*note Regexp::).
+
+     The parts of STRING that are not covered by any match of REGEXP
+     are copied to the expansion.  Whenever a match is found, the
+     search proceeds from the end of the match, so a character from
+     STRING will never be substituted twice.  If REGEXP matches a
+     string of zero length, the start position for the search is
+     incremented, to avoid infinite loops.
+
+     When a replacement is to be made, REPLACEMENT is inserted into the
+     expansion, with `\N' substituted by the text matched by the Nth
+     parenthesized sub-expression of PATSUBST, for up to nine
+     sub-expressions.  The escape `\&' is replaced by the text of the
+     entire regular expression matched.  For all other characters, `\'
+     treats the next character literally.  A warning is issued if there
+     were fewer sub-expressions than the `\N' requested, or if there is
+     a trailing `\'.
+
+     The REPLACEMENT argument can be omitted, in which case the text
+     matched by REGEXP is deleted.
+
+     The macro `patsubst' is recognized only with parameters.
+
+     patsubst(`GNUs not Unix', `^', `OBS: ')
+     =>OBS: GNUs not Unix
+     patsubst(`GNUs not Unix', `\<', `OBS: ')
+     =>OBS: GNUs OBS: not OBS: Unix
+     patsubst(`GNUs not Unix', `\w*', `(\&)')
+     =>(GNUs)() (not)() (Unix)()
+     patsubst(`GNUs not Unix', `\w+', `(\&)')
+     =>(GNUs) (not) (Unix)
+     patsubst(`GNUs not Unix', `[A-Z][a-z]+')
+     =>GN not 
+     patsubst(`GNUs not Unix', `not', `NOT\')
+     error-->m4:stdin:6: Warning: trailing \ ignored in replacement
+     =>GNUs NOT Unix
+
+   Here is a slightly more realistic example, which capitalizes
+individual word or whole sentences, by substituting calls of the macros
+`upcase' and `downcase' into the strings.
+
+ -- Composite: upcase (TEXT)
+ -- Composite: downcase (TEXT)
+ -- Composite: capitalize (TEXT)
+     Expand to TEXT, but with capitalization changed: `upcase' changes
+     all letters to upper case, `downcase' changes all letters to lower
+     case, and `capitalize' changes the first character of each word to
+     upper case and the remaining characters to lower case.
+
+     define(`upcase', `translit(`$*', `a-z', `A-Z')')dnl
+     define(`downcase', `translit(`$*', `A-Z', `a-z')')dnl
+     define(`capitalize1',
+            `regexp(`$1', `^\(\w\)\(\w*\)',
+                    `upcase(`\1')`'downcase(`\2')')')dnl
+     define(`capitalize',
+            `patsubst(`$1', `\w+', `capitalize1(`\&')')')dnl
+     capitalize(`GNUs not Unix')
+     =>Gnus Not Unix
+
+   While `regexp' replaces the whole input with the replacement as soon
+as there is a match, `patsubst' replaces each _occurrence_ of a match
+and preserves non-matching pieces:
+
+     define(`patreg',
+     `patsubst($@)
+     regexp($@)')dnl
+     patreg(`bar foo baz Foo', `foo\|Foo', `FOO')
+     =>bar FOO baz FOO
+     =>FOO
+     patreg(`aba abb 121', `\(.\)\(.\)\1', `\2\1\2')
+     =>bab abb 212
+     =>bab
+
+   Omitting REGEXP evokes a warning, but still produces output.
+
+     patsubst(`abc')
+     error-->m4:stdin:1: Warning: too few arguments to builtin `patsubst'
+     =>abc
+
+
+File: m4.info,  Node: Format,  Prev: Patsubst,  Up: Text handling
+
+11.7 Formatted output
+=====================
+
+Formatted output can be made with `format':
+
+ -- Builtin: format (FORMAT-STRING, ...)
+     Works much like the C function `printf'.  The first argument
+     FORMAT-STRING can contain `%' specifications which are satisfied
+     by additional arguments, and the expansion of `format' is the
+     formatted string.
+
+     The macro `format' is recognized only with parameters.
+
+   Its use is best described by a few examples:
+
+     define(`foo', `The brown fox jumped over the lazy dog')
+     =>
+     format(`The string "%s" uses %d characters', foo, len(foo))
+     =>The string "The brown fox jumped over the lazy dog" uses 38 characters
+     format(`%.0f', `56789.9876')
+     =>56790
+     len(format(`%-*X', `300', `1'))
+     =>300
+
+   Using the `forloop' macro defined earlier (*note Forloop::), this
+example shows how `format' can be used to produce tabular output.
+
+     include(`forloop.m4')
+     =>
+     forloop(`i', `1', `10', `format(`%6d squared is %10d
+     ', i, eval(i**2))')
+     =>     1 squared is          1
+     =>     2 squared is          4
+     =>     3 squared is          9
+     =>     4 squared is         16
+     =>     5 squared is         25
+     =>     6 squared is         36
+     =>     7 squared is         49
+     =>     8 squared is         64
+     =>     9 squared is         81
+     =>    10 squared is        100
+     =>
+
+   The builtin `format' is modeled after the ANSI C `printf' function,
+and supports these `%' specifiers: `c', `s', `d', `o', `x', `X', `u',
+`e', `E', `f', `F', `g', `G', and `%'; it supports field widths and
+precisions, and the modifiers `+', `-', ` ', `0', `#', `h' and `l'.
+For more details on the functioning of `printf', see the C Library
+Manual.
+
+   For now, unrecognized specifiers are silently ignored, but it is
+anticipated that a future release of GNU `m4' will support more
+specifiers, and give warnings when problems are encountered.  Likewise,
+escape sequences are not yet recognized.
+
+
+File: m4.info,  Node: Arithmetic,  Next: Shell commands,  Prev: Text handling,  Up: Top
+
+12 Macros for doing arithmetic
+******************************
+
+Integer arithmetic is included in `m4', with a C-like syntax.  As
+convenient shorthands, there are builtins for simple increment and
+decrement operations.
+
+* Menu:
+
+* Incr::                        Decrement and increment operators
+* Eval::                        Evaluating integer expressions
+
+
+File: m4.info,  Node: Incr,  Next: Eval,  Up: Arithmetic
+
+12.1 Decrement and increment operators
+======================================
+
+Increment and decrement of integers are supported using the builtins
+`incr' and `decr':
+
+ -- Builtin: incr (NUMBER)
+ -- Builtin: decr (NUMBER)
+     Expand to the numerical value of NUMBER, incremented or
+     decremented, respectively, by one.  Except for the empty string,
+     the expansion is empty if NUMBER could not be parsed.
+
+     The macros `incr' and `decr' are recognized only with parameters.
+
+     incr(`4')
+     =>5
+     decr(`7')
+     =>6
+     incr()
+     error-->m4:stdin:3: empty string treated as 0 in builtin `incr'
+     =>1
+     decr()
+     error-->m4:stdin:4: empty string treated as 0 in builtin `decr'
+     =>-1
+
+
+File: m4.info,  Node: Eval,  Prev: Incr,  Up: Arithmetic
+
+12.2 Evaluating integer expressions
+===================================
+
+Integer expressions are evaluated with `eval':
+
+ -- Builtin: eval (EXPRESSION, [RADIX = `10'], [WIDTH])
+     Expands to the value of EXPRESSION.  The expansion is empty if an
+     error is encountered while parsing the arguments.  If specified,
+     RADIX and WIDTH control the format of the output.
+
+     The macro `eval' is recognized only with parameters.
+
+   Expressions can contain the following operators, listed in order of
+decreasing precedence.
+
+`+ -'
+     Unary plus and minus
+
+`**'
+     Exponentiation
+
+`*  /  %'
+     Multiplication, division and modulo
+
+`+  -'
+     Addition and subtraction
+
+`<<  >>'
+     Shift left or right
+
+`==  !=  >  >=  <  <='
+     Relational operators
+
+`!'
+     Logical negation
+
+`~'
+     Bitwise negation
+
+`&'
+     Bitwise and
+
+`^'
+     Bitwise exclusive-or
+
+`|'
+     Bitwise or
+
+`&&'
+     Logical and
+
+`||'
+     Logical or
+
+   All operators, except exponentiation, are left associative.
+
+   Note that some older `m4' implementations use `^' as an alternate
+operator for exponentiation, although POSIX requires the C behavior of
+bitwise exclusive-or.  On the other hand, the precedence of `~' and `!'
+are different in GNU `m4' than they are in C, matching the precedence
+in traditional `m4' implementations.  This behavior is likely to change
+in a future version to match POSIX, so use parentheses to force the
+desired precedence.
+
+   Within EXPRESSION, (but not RADIX or WIDTH), numbers without a
+special prefix are decimal.  A simple `0' prefix introduces an octal
+number.  `0x' introduces a hexadecimal number.  `0b' introduces a
+binary number.  `0r' introduces a number expressed in any radix between
+1 and 36: the prefix should be immediately followed by the decimal
+expression of the radix, a colon, then the digits making the number.
+For radix 1, leading zeros are ignored and all remaining digits must be
+`1'; for all other radices, the digits are `0', `1', `2', ....  Beyond
+`9', the digits are `a', `b' ... up to `z'.  Lower and upper case
+letters can be used interchangeably in numbers prefixes and as number
+digits.
+
+   Parentheses may be used to group subexpressions whenever needed.
+For the relational operators, a true relation returns `1', and a false
+relation return `0'.
+
+   Here are a few examples of use of `eval'.
+
+     eval(`-3 * 5')
+     =>-15
+     eval(index(`Hello world', `llo') >= 0)
+     =>1
+     eval(`0r1:0111 + 0b100 + 0r3:12')
+     =>12
+     define(`square', `eval(`('$1`)**2')')
+     =>
+     square(`9')
+     =>81
+     square(square(`5')`+1')
+     =>676
+     define(`foo', `666')
+     =>
+     eval(`foo/6')
+     error-->m4:stdin:8: bad expression in eval: foo/6
+     =>
+     eval(foo/6)
+     =>111
+
+   As the last two lines show, `eval' does not handle macro names, even
+if they expand to a valid expression (or part of a valid expression).
+Therefore all macros must be expanded before they are passed to `eval'.
+
+   All evaluation is done with 32-bit signed integers, assuming
+2's-complement with wrap-around.  The shift operators are defined in GNU
+`m4' by doing an implicit bit-wise and of the right-hand operand with
+0x1f, and sign-extension with right shift.
+
+     eval(0x80000000 / -1)
+     =>-2147483648
+     eval(0x80000000 % -1)
+     =>0
+     eval(0x7fffffff)
+     =>2147483647
+     incr(eval(0x7fffffff))
+     =>-2147483648
+     eval(-4 >> 33)
+     =>-2
+
+   If RADIX is specified, it specifies the radix to be used in the
+expansion.  The default radix is 10; this is also the case if RADIX is
+the empty string.  It is an error if the radix is outside the range of
+1 through 36, inclusive.  The result of `eval' is always taken to be
+signed.  No radix prefix is output, and for radices greater than 10,
+the digits are lower case.  The WIDTH argument specifies the minimum
+output width, excluding any negative sign.  The result is zero-padded
+to extend the expansion to the requested width.  It is an error if the
+width is negative.  On error, the expansion of `eval' is empty.
+
+     eval(`666', `10')
+     =>666
+     eval(`666', `11')
+     =>556
+     eval(`666', `6')
+     =>3030
+     eval(`666', `6', `10')
+     =>0000003030
+     eval(`-666', `6', `10')
+     =>-0000003030
+     eval(`10', `', `0')
+     =>10
+     `0r1:'eval(`10', `1', `11')
+     =>0r1:01111111111
+     eval(`10', `16')
+     =>a
+
+
+File: m4.info,  Node: Shell commands,  Next: Miscellaneous,  Prev: Arithmetic,  Up: Top
+
+13 Macros for running shell commands
+************************************
+
+There are a few builtin macros in `m4' that allow you to run shell
+commands from within `m4'.
+
+   Note that the definition of a valid shell command is system
+dependent.  On UNIX systems, this is the typical `/bin/sh'.  But on
+other systems, such as native Windows, the shell has a different syntax
+of commands that it understands.  Some examples in this chapter assume
+`/bin/sh', and also demonstrate how to quit early with a known exit
+value if this is not the case.
+
+* Menu:
+
+* Platform macros::             Determining the platform
+* Syscmd::                      Executing simple commands
+* Esyscmd::                     Reading the output of commands
+* Sysval::                      Exit status
+* Mkstemp::                     Making temporary files
+
+
+File: m4.info,  Node: Platform macros,  Next: Syscmd,  Up: Shell commands
+
+13.1 Determining the platform
+=============================
+
+Sometimes it is desirable for an input file to know which platform `m4'
+is running on.  GNU `m4' provides several macros that are predefined to
+expand to the empty string; checking for their existence will confirm
+platform details.
+
+ -- Optional builtin: __gnu__
+ -- Optional builtin: __os2__
+ -- Optional builtin: os2
+ -- Optional builtin: __unix__
+ -- Optional builtin: unix
+ -- Optional builtin: __windows__
+ -- Optional builtin: windows
+     Each of these macros is conditionally defined as needed to
+     describe the environment of `m4'.  If defined, each macro expands
+     to the empty string.
+
+   When GNU extensions are in effect (that is, when you did not use the
+`-G' option, *note Invoking m4: Limits control.), GNU `m4' will define
+the macro `__gnu__' to expand to the empty string.
+
+     __gnu__
+     =>
+     ifdef(`__gnu__', `Extensions are active')
+     =>Extensions are active
+
+   On UNIX systems, GNU `m4' will define `__unix__' by default, or
+`unix' when the `-G' option is specified.
+
+   On native Windows systems, GNU `m4' will define `__windows__' by
+default, or `windows' when the `-G' option is specified.
+
+   On OS/2 systems, GNU `m4' will define `__os2__' by default, or `os2'
+when the `-G' option is specified.
+
+   If GNU `m4' does not provide a platform macro for your system,
+please report that as a bug.
+
+     define(`provided', `0')
+     =>
+     ifdef(`__unix__', `define(`provided', incr(provided))')
+     =>
+     ifdef(`__windows__', `define(`provided', incr(provided))')
+     =>
+     ifdef(`__os2__', `define(`provided', incr(provided))')
+     =>
+     provided
+     =>1
+
+
+File: m4.info,  Node: Syscmd,  Next: Esyscmd,  Prev: Platform macros,  Up: Shell commands
+
+13.2 Executing simple commands
+==============================
+
+Any shell command can be executed, using `syscmd':
+
+ -- Builtin: syscmd (SHELL-COMMAND)
+     Executes SHELL-COMMAND as a shell command.
+
+     The expansion of `syscmd' is void, _not_ the output from
+     SHELL-COMMAND!  Output or error messages from SHELL-COMMAND are
+     not read by `m4'.  *Note Esyscmd::, if you need to process the
+     command output.
+
+     Prior to executing the command, `m4' flushes its buffers.  The
+     default standard input, output and error of SHELL-COMMAND are the
+     same as those of `m4'.
+
+     The macro `syscmd' is recognized only with parameters.
+
+     define(`foo', `FOO')
+     =>
+     syscmd(`echo foo')
+     =>foo
+     =>
+
+   Note how the expansion of `syscmd' keeps the trailing newline of the
+command, as well as using the newline that appeared after the macro.
+
+   As an example of SHELL-COMMAND using the same standard input as
+`m4', the command line `echo "m4wrap(\`syscmd(\`cat')')" | m4' will
+tell `m4' to read all of its input before executing the wrapped text,
+then hand a valid (albeit emptied) pipe as standard input for the `cat'
+subcommand.  Therefore, you should be careful when using standard input
+(either by specifying no files, or by passing `-' as a file name on the
+command line, *note Invoking m4: Command line files.), and also
+invoking subcommands via `syscmd' or `esyscmd' that consume data from
+standard input.  When standard input is a seekable file, the subprocess
+will pick up with the next character not yet processed by `m4'; when it
+is a pipe or other non-seekable file, there is no guarantee how much
+data will already be buffered by `m4' and thus unavailable to the child.
+
+
+File: m4.info,  Node: Esyscmd,  Next: Sysval,  Prev: Syscmd,  Up: Shell commands
+
+13.3 Reading the output of commands
+===================================
+
+If you want `m4' to read the output of a shell command, use `esyscmd':
+
+ -- Builtin: esyscmd (SHELL-COMMAND)
+     Expands to the standard output of the shell command SHELL-COMMAND.
+
+     Prior to executing the command, `m4' flushes its buffers.  The
+     default standard input and standard error of SHELL-COMMAND are the
+     same as those of `m4'.  The error output of SHELL-COMMAND is not a
+     part of the expansion: it will appear along with the error output
+     of `m4'.
+
+     The macro `esyscmd' is recognized only with parameters.
+
+     define(`foo', `FOO')
+     =>
+     esyscmd(`echo foo')
+     =>FOO
+     =>
+
+   Note how the expansion of `esyscmd' keeps the trailing newline of
+the command, as well as using the newline that appeared after the macro.
+
+   Just as with `syscmd', care must be exercised when sharing standard
+input between `m4' and the child process of `esyscmd'.
+
+
+File: m4.info,  Node: Sysval,  Next: Mkstemp,  Prev: Esyscmd,  Up: Shell commands
+
+13.4 Exit status
+================
+
+To see whether a shell command succeeded, use `sysval':
+
+ -- Builtin: sysval
+     Expands to the exit status of the last shell command run with
+     `syscmd' or `esyscmd'.  Expands to 0 if no command has been run
+     yet.
+
+     syscmd(`false')
+     =>
+     ifelse(sysval, `0', `zero', `non-zero')
+     =>non-zero
+     syscmd(`exit 2')
+     =>
+     sysval
+     =>2
+     syscmd(`true')
+     =>
+     sysval
+     =>0
+     esyscmd(`false')
+     =>
+     ifelse(sysval, `0', `zero', `non-zero')
+     =>non-zero
+     esyscmd(`exit 2')
+     =>
+     sysval
+     =>2
+     esyscmd(`true')
+     =>
+     sysval
+     =>0
+
+   `sysval' results in 127 if there was a problem executing the
+command, for example, if the system-imposed argument length is exceeded,
+or if there were not enough resources to fork.  It is not possible to
+distinguish between failed execution and successful execution that had
+an exit status of 127.
+
+   On UNIX platforms, where it is possible to detect when command
+execution is terminated by a signal, rather than a normal exit, the
+result is the signal number shifted left by eight bits.
+
+     dnl This test assumes kill is a shell builtin, and that signals are
+     dnl recognizable.
+     ifdef(`__unix__', ,
+           `errprint(` skipping: syscmd does not have unix semantics
+     ')m4exit(`77')')dnl
+     syscmd(`kill -13 $$')
+     =>
+     sysval
+     =>3328
+     esyscmd(`kill -9 $$')
+     =>
+     sysval
+     =>2304
+
+
+File: m4.info,  Node: Mkstemp,  Prev: Sysval,  Up: Shell commands
+
+13.5 Making temporary files
+===========================
+
+Commands specified to `syscmd' or `esyscmd' might need a temporary
+file, for output or for some other purpose.  There is a builtin macro,
+`mkstemp', for making a temporary file:
+
+ -- Builtin: mkstemp (TEMPLATE)
+ -- Builtin: maketemp (TEMPLATE)
+     Expands to a name of a new, empty file, made from the string
+     TEMPLATE, which should end with the string `XXXXXX'.  The six `X'
+     characters are then replaced with random characters matching the
+     regular expression `[a-zA-Z0-9._-]', in order to make the file
+     name unique.  If fewer than six `X' characters are found at the end
+     of `template', the result will be longer than the template.  The
+     created file will have access permissions as if by `chmod =rw,go=',
+     meaning that the current umask of the `m4' process is taken into
+     account, and at most only the current user can read and write the
+     file.
+
+     The traditional behavior, standardized by POSIX, is that
+     `maketemp' merely replaces the trailing `X' with the process id,
+     without creating a file, and without ensuring that the resulting
+     string is a unique file name.  In part, this means that using the
+     same TEMPLATE twice in the same input file will result in the same
+     expansion.  This behavior is a security hole, as it is very easy
+     for another process to guess the name that will be generated, and
+     thus interfere with a subsequent use of `syscmd' trying to
+     manipulate that file name.  Hence, POSIX has recommended that all
+     new implementations of `m4' provide the secure `mkstemp' builtin,
+     and that users of `m4' check for its existence.
+
+     The macros `mkstemp' and `maketemp' are recognized only with
+     parameters.
+
+   If you try this next example, you will most likely get different
+output for the two file names, since the replacement characters are
+randomly chosen:
+
+     maketemp(`/tmp/fooXXXXXX')
+     =>/tmp/fooa07346
+     ifdef(`mkstemp', `define(`maketemp', defn(`mkstemp'))',
+           `define(`mkstemp', defn(`maketemp'))dnl
+     errprint(`warning: potentially insecure maketemp implementation
+     ')')
+     =>
+     mkstemp(`doc')
+     =>docQv83Uw
+
+   Unless you use the `--traditional' command line option (or `-G',
+*note Invoking m4: Limits control.), the GNU version of `maketemp' is
+secure.  This means that using the same template to multiple calls will
+generate multiple files.  However, we recommend that you use the new
+`mkstemp' macro, introduced in GNU M4 1.4.8, which is secure even in
+traditional mode.
+
+     syscmd(`echo foo??????')dnl
+     =>foo??????
+     define(`file1', maketemp(`fooXXXXXX'))dnl
+     ifelse(esyscmd(`echo foo??????'), `foo??????', `no file', `created')
+     =>created
+     define(`file2', maketemp(`fooXX'))dnl
+     define(`file3', mkstemp(`fooXXXXXX'))dnl
+     ifelse(len(file1), len(file2), `same length', `different')
+     =>same length
+     ifelse(file1, file2, `same', `different file')
+     =>different file
+     ifelse(file2, file3, `same', `different file')
+     =>different file
+     ifelse(file1, file3, `same', `different file')
+     =>different file
+     syscmd(`rm 'file1 file2 file3)
+     =>
+     sysval
+     =>0
+
+
+File: m4.info,  Node: Miscellaneous,  Next: Frozen files,  Prev: Shell commands,  Up: Top
+
+14 Miscellaneous builtin macros
+*******************************
+
+This chapter describes various builtins, that do not really belong in
+any of the previous chapters.
+
+* Menu:
+
+* Errprint::                    Printing error messages
+* Location::                    Printing current location
+* M4exit::                      Exiting from `m4'
+
+
+File: m4.info,  Node: Errprint,  Next: Location,  Up: Miscellaneous
+
+14.1 Printing error messages
+============================
+
+You can print error messages using `errprint':
+
+ -- Builtin: errprint (MESSAGE, ...)
+     Prints MESSAGE and the rest of the arguments to standard error,
+     separated by spaces.  Standard error is used, regardless of the
+     `--debugfile' option (*note Invoking m4: Debugging options.).
+
+     The expansion of `errprint' is void.  The macro `errprint' is
+     recognized only with parameters.
+
+     errprint(`Invalid arguments to forloop
+     ')
+     error-->Invalid arguments to forloop
+     =>
+     errprint(`1')errprint(`2',`3
+     ')
+     error-->12 3
+     =>
+
+   A trailing newline is _not_ printed automatically, so it should be
+supplied as part of the argument, as in the example.  Unfortunately, the
+exact output of `errprint' is not very portable to other `m4'
+implementations: POSIX requires that all arguments be printed, but some
+implementations of `m4' only print the first.  Furthermore, some BSD
+implementations always append a newline for each `errprint' call,
+regardless of whether the last argument already had one, and POSIX is
+silent on whether this is acceptable.
+
+
+File: m4.info,  Node: Location,  Next: M4exit,  Prev: Errprint,  Up: Miscellaneous
+
+14.2 Printing current location
+==============================
+
+To make it possible to specify the location of an error, three utility
+builtins exist:
+
+ -- Builtin: __file__
+ -- Builtin: __line__
+ -- Builtin: __program__
+     Expand to the quoted name of the current input file, the current
+     input line number in that file, and the quoted name of the current
+     invocation of `m4'.
+
+     errprint(__program__:__file__:__line__: `input error
+     ')
+     error-->m4:stdin:1: input error
+     =>
+
+   Line numbers start at 1 for each file.  If the file was found due to
+the `-I' option or `M4PATH' environment variable, that is reflected in
+the file name.  The syncline option (`-s', *note Invoking m4:
+Preprocessor features.), and the `f' and `l' flags of `debugmode'
+(*note Debug Levels::), also use this notion of current file and line.
+Redefining the three location macros has no effect on syncline, debug,
+or warning message output.  Assume this example is run in the
+`m4-1.4.8/checks' directory of the GNU M4 package, using
+`--include=../examples' in the command line to find the file `incl.m4'
+mentioned earlier:
+
+     define(`foo', ``$0' called at __file__:__line__')
+     =>
+     foo
+     =>foo called at stdin:2
+     include(`incl.m4')
+     =>Include file start
+     =>foo called at ../examples/incl.m4:2
+     =>Include file end
+     =>
+
+   The location of macros invoked during the rescanning of macro
+expansion text corresponds to the location in the file where the
+expansion was triggered, regardless of how many newline characters the
+expansion text contains.  As of GNU M4 1.4.8, the location of text
+wrapped with `m4wrap' (*note M4wrap::) is the point at which the
+`m4wrap' was invoked.  Previous versions, however, behaved as though
+wrapped text came from line 0 of the file "".
+
+     define(`echo', `$@')
+     =>
+     define(`foo', `echo(__line__
+     __line__)')
+     =>
+     echo(__line__
+     __line__)
+     =>4
+     =>5
+     m4wrap(`foo
+     ')
+     =>
+     foo(errprint(__line__
+     __line__
+     ))
+     error-->8
+     error-->9
+     =>8
+     =>8
+     __line__
+     =>11
+     ^D
+     =>6
+     =>6
+
+   The `__program__' macro behaves like `$0' in shell terminology.  If
+you invoke `m4' through an absolute path or a link with a different
+spelling, rather than by relying on a `PATH' search for plain `m4', it
+will affect how `__program__' expands.  The intent is that you can use
+it to produce error messages with the same formatting that `m4'
+produces internally.  It can also be used within `syscmd' (*note
+Syscmd::) to pick the same version of `m4' that is currently running,
+rather than whatever version of `m4' happens to be first in `PATH'.  It
+was first introduced in GNU M4 1.4.6.
+
+
+File: m4.info,  Node: M4exit,  Prev: Location,  Up: Miscellaneous
+
+14.3 Exiting from `m4'
+======================
+
+If you need to exit from `m4' before the entire input has been read,
+you can use `m4exit':
+
+ -- Builtin: m4exit ([CODE = `0'])
+     Causes `m4' to exit, with exit status CODE.  If CODE is left out,
+     the exit status is zero.  If CODE cannot be parsed, or is outside
+     the range of 0 to 255, the exit status is one.  No further input
+     is read, and all wrapped and diverted text is discarded.
+
+     m4wrap(`This text is lost due to `m4exit'.')
+     =>
+     divert(`1') So is this.
+     divert
+     =>
+     m4exit And this is never read.
+
+   A common use of this is to abort processing:
+
+ -- Composite: fatal_error (MESSAGE)
+     Abort processing with an error message and non-zero status.  Prefix
+     MESSAGE with details about where the error occurred, and print the
+     resulting string to standard error.
+
+     define(`fatal_error',
+            `errprint(__program__:__file__:__line__`: fatal error: $*
+     ')m4exit(`1')')
+     =>
+     fatal_error(`this is a BAD one, buster')
+     error-->m4:stdin:4: fatal error: this is a BAD one, buster
+
+   After this macro call, `m4' will exit with exit status 1.  This macro
+is only intended for error exits, since the normal exit procedures are
+not followed, e.g., diverted text is not undiverted, and saved text
+(*note M4wrap::) is not reread.  (This macro could be made more robust
+to earlier versions of `m4'.  You should try to see if you can find
+weaknesses and correct them; or *note Answers: Improved fatal_error.).
+
+   Note that it is still possible for the exit status to be different
+than what was requested by `m4exit'.  If `m4' detects some other error,
+such as a write error on standard output, the exit status will be
+non-zero even if `m4exit' requested zero.
+
+   If standard input is seekable, then the file will be positioned at
+the next unread character.  If it is a pipe or other non-seekable file,
+then there are no guarantees how much data `m4' might have read into
+buffers, and thus discarded.
+
+
+File: m4.info,  Node: Frozen files,  Next: Compatibility,  Prev: Miscellaneous,  Up: Top
+
+15 Fast loading of frozen state
+*******************************
+
+Some bigger `m4' applications may be built over a common base
+containing hundreds of definitions and other costly initializations.
+Usually, the common base is kept in one or more declarative files,
+which files are listed on each `m4' invocation prior to the user's
+input file, or else each input file uses `include'.
+
+   Reading the common base of a big application, over and over again,
+may be time consuming.  GNU `m4' offers some machinery to speed up the
+start of an application using lengthy common bases.
+
+* Menu:
+
+* Using frozen files::          Using frozen files
+* Frozen file format::          Frozen file format
+
+
+File: m4.info,  Node: Using frozen files,  Next: Frozen file format,  Up: Frozen files
+
+15.1 Using frozen files
+=======================
+
+Suppose a user has a library of `m4' initializations in `base.m4',
+which is then used with multiple input files:
+
+     m4 base.m4 input1.m4
+     m4 base.m4 input2.m4
+     m4 base.m4 input3.m4
+
+   Rather than spending time parsing the fixed contents of `base.m4'
+every time, the user might rather execute:
+
+     m4 -F base.m4f base.m4
+
+once, and further execute, as often as needed:
+
+     m4 -R base.m4f input1.m4
+     m4 -R base.m4f input2.m4
+     m4 -R base.m4f input3.m4
+
+with the varying input.  The first call, containing the `-F' option,
+only reads and executes file `base.m4', defining various application
+macros and computing other initializations.  Once the input file
+`base.m4' has been completely processed, GNU `m4' produces on
+`base.m4f' a "frozen" file, that is, a file which contains a kind of
+snapshot of the `m4' internal state.
+
+   Later calls, containing the `-R' option, are able to reload the
+internal state of `m4', from `base.m4f', _prior_ to reading any other
+input files.  This means instead of starting with a virgin copy of
+`m4', input will be read after having effectively recovered the effect
+of a prior run.  In our example, the effect is the same as if file
+`base.m4' has been read anew.  However, this effect is achieved a lot
+faster.
+
+   Only one frozen file may be created or read in any one `m4'
+invocation.  It is not possible to recover two frozen files at once.
+However, frozen files may be updated incrementally, through using `-R'
+and `-F' options simultaneously.  For example, if some care is taken,
+the command:
+
+     m4 file1.m4 file2.m4 file3.m4 file4.m4
+
+could be broken down in the following sequence, accumulating the same
+output:
+
+     m4 -F file1.m4f file1.m4
+     m4 -R file1.m4f -F file2.m4f file2.m4
+     m4 -R file2.m4f -F file3.m4f file3.m4
+     m4 -R file3.m4f file4.m4
+
+   Some care is necessary because not every effort has been made for
+this to work in all cases.  In particular, the trace attribute of
+macros is not handled, nor the current setting of `changeword'.
+Currently, `m4wrap' and `sysval' also have problems.  Also,
+interactions for some options of `m4', being used in one call and not
+in the next, have not been fully analyzed yet.  On the other end, you
+may be confident that stacks of `pushdef' definitions are handled
+correctly, as well as undefined or renamed builtins, and changed
+strings for quotes or comments.  And future releases of GNU M4 will
+improve on the utility of frozen files.
+
+   When an `m4' run is to be frozen, the automatic undiversion which
+takes place at end of execution is inhibited.  Instead, all positively
+numbered diversions are saved into the frozen file.  The active
+diversion number is also transmitted.
+
+   A frozen file to be reloaded need not reside in the current
+directory.  It is looked up the same way as an `include' file (*note
+Search Path::).
+
+   If the frozen file was generated with a newer version of `m4', and
+contains directives that an older `m4' cannot parse, attempting to load
+the frozen file with option `-R' will cause `m4' to exit with status 63
+to indicate version mismatch.
+
+
+File: m4.info,  Node: Frozen file format,  Prev: Using frozen files,  Up: Frozen files
+
+15.2 Frozen file format
+=======================
+
+Frozen files are sharable across architectures.  It is safe to write a
+frozen file on one machine and read it on another, given that the
+second machine uses the same or newer version of GNU `m4'.  It is
+conventional, but not required, to give a frozen file the suffix of
+`.m4f'.
+
+   These are simple (editable) text files, made up of directives, each
+starting with a capital letter and ending with a newline (<NL>).
+Wherever a directive is expected, the character `#' introduces a
+comment line; empty lines are also ignored if they are not part of an
+embedded string.  In the following descriptions, each LEN refers to the
+length of the corresponding strings STR in the next line of input.
+Numbers are always expressed in decimal.  There are no escape
+characters.  The directives are:
+
+`C LEN1 , LEN2 <NL> STR1 STR2 <NL>'
+     Uses STR1 and STR2 as the begin-comment and end-comment strings.
+     If omitted, then `#' and <NL> are the comment delimiters.
+
+`D NUMBER, LEN <NL> STR <NL>'
+     Selects diversion NUMBER, making it current, then copy STR in the
+     current diversion.  NUMBER may be a negative number for a
+     non-existing diversion.  To merely specify an active selection,
+     use this command with an empty STR.  With 0 as the diversion
+     NUMBER, STR will be issued on standard output at reload time.  GNU
+     `m4' will not produce the `D' directive with non-zero length for
+     diversion 0, but this can be done with manual edits.  This
+     directive may appear more than once for the same diversion, in
+     which case the diversion is the concatenation of the various uses.
+     If omitted, then diversion 0 is current.
+
+`F LEN1 , LEN2 <NL> STR1 STR2 <NL>'
+     Defines, through `pushdef', a definition for STR1 expanding to the
+     function whose builtin name is STR2.  If the builtin does not
+     exist (for example, if the frozen file was produced by a copy of
+     `m4' compiled with changeword support, but the version of `m4'
+     reloading was compiled without it), the reload is silent, but any
+     subsequent use of the definition of STR1 will result in a warning.
+     This directive may appear more than once for the same name, and
+     its order, along with `T', is important.  If omitted, you will
+     have no access to any builtins.
+
+`Q LEN1 , LEN2 <NL> STR1 STR2 <NL>'
+     Uses STR1 and STR2 as the begin-quote and end-quote strings.  If
+     omitted, then ``' and `'' are the quote delimiters.
+
+`T LEN1 , LEN2 <NL> STR1 STR2 <NL>'
+     Defines, though `pushdef', a definition for STR1 expanding to the
+     text given by STR2.  This directive may appear more than once for
+     the same name, and its order, along with `F', is important.
+
+`V NUMBER <NL>'
+     Confirms the format of the file.  `m4' 1.4.8 only creates and
+     understands frozen files where NUMBER is 1.  This directive must
+     be the first non-comment in the file, and may not appear more than
+     once.
+
+
+File: m4.info,  Node: Compatibility,  Next: Answers,  Prev: Frozen files,  Up: Top
+
+16 Compatibility with other versions of `m4'
+********************************************
+
+This chapter describes the differences between this implementation of
+`m4', and the implementation found under UNIX, notably System V,
+Release 3.
+
+   There are also differences in BSD flavors of `m4'.  No attempt is
+made to summarize these here.
+
+* Menu:
+
+* Extensions::                  Extensions in GNU M4
+* Incompatibilities::           Facilities in System V m4 not in GNU M4
+* Other Incompatibilities::     Other incompatibilities
+
+
+File: m4.info,  Node: Extensions,  Next: Incompatibilities,  Up: Compatibility
+
+16.1 Extensions in GNU `m4'
+===========================
+
+This version of `m4' contains a few facilities that do not exist in
+System V `m4'.  These extra facilities are all suppressed by using the
+`-G' command line option (*note Invoking m4: Limits control.), unless
+overridden by other command line options.
+
+   * In the `$'N notation for macro arguments, N can contain several
+     digits, while the System V `m4' only accepts one digit.  This
+     allows macros in GNU `m4' to take any number of arguments, and not
+     only nine (*note Arguments::).
+
+     This means that `define(`foo', `$11')' is ambiguous between
+     implementations.  To portably choose between grabbing the first
+     parameter and appending 1 to the expansion, or grabbing the
+     eleventh parameter, you can do the following:
+
+          define(`a1', `A1')
+          =>
+          dnl First argument, concatenated with 1
+          define(`_1', `$1')define(`first1', `_1($@)1')
+          =>
+          dnl Eleventh argument, portable
+          define(`_9', `$9')define(`eleventh', `_9(shift(shift($@)))')
+          =>
+          dnl Eleventh argument, GNU style
+          define(`Eleventh', `$11')
+          =>
+          first1(`a', `b', `c', `d', `e', `f', `g', `h', `i', `j', `k')
+          =>A1
+          eleventh(`a', `b', `c', `d', `e', `f', `g', `h', `i', `j', `k')
+          =>k
+          Eleventh(`a', `b', `c', `d', `e', `f', `g', `h', `i', `j', `k')
+          =>k
+
+   * The `divert' (*note Divert::) macro can manage more than 9
+     diversions.  GNU `m4' treats all positive numbers as valid
+     diversions, rather than discarding diversions greater than 9.
+
+   * Files included with `include' and `sinclude' are sought in a user
+     specified search path, if they are not found in the working
+     directory.  The search path is specified by the `-I' option and the
+     `M4PATH' environment variable (*note Search Path::).
+
+   * Arguments to `undivert' can be non-numeric, in which case the named
+     file will be included uninterpreted in the output (*note
+     Undivert::).
+
+   * Formatted output is supported through the `format' builtin, which
+     is modeled after the C library function `printf' (*note Format::).
+
+   * Searches and text substitution through regular expressions are
+     supported by the `regexp' (*note Regexp::) and `patsubst' (*note
+     Patsubst::) builtins.
+
+   * The output of shell commands can be read into `m4' with `esyscmd'
+     (*note Esyscmd::).
+
+   * There is indirect access to any builtin macro with `builtin'
+     (*note Builtin::).
+
+   * Macros can be called indirectly through `indir' (*note Indir::).
+
+   * The name of the program, the current input file, and the current
+     input line number are accessible through the builtins
+     `__program__', `__file__', and `__line__' (*note Location::).
+
+   * The format of the output from `dumpdef' and macro tracing can be
+     controlled with `debugmode' (*note Debug Levels::).
+
+   * The destination of trace and debug output can be controlled with
+     `debugfile' (*note Debug Output::).
+
+   * The `maketemp' (*note Mkstemp::) macro behaves like `mkstemp',
+     creating a new file with a unique name on every invocation, rather
+     than following the insecure behavior of replacing the trailing `X'
+     characters with the `m4' process id.
+
+   In addition to the above extensions, GNU `m4' implements the
+following command line options: `-F', `-G', `-I', `-L', `-R', `-V',
+`-W', `-d', `-i', `-l', `--debugfile' and `-t'.  *Note Invoking m4::,
+for a description of these options.
+
+   Also, the debugging and tracing facilities in GNU `m4' are much more
+extensive than in most other versions of `m4'.
+
+
+File: m4.info,  Node: Incompatibilities,  Next: Other Incompatibilities,  Prev: Extensions,  Up: Compatibility
+
+16.2 Facilities in System V `m4' not in GNU `m4'
+================================================
+
+The version of `m4' from System V contains a few facilities that have
+not been implemented in GNU `m4' yet.  Additionally, POSIX requires
+some behaviors that GNU `m4' has not implemented yet.  Relying on these
+behaviors is non-portable, as a future release of GNU `m4' may change.
+
+   * System V `m4' supports multiple arguments to `defn', and POSIX
+     requires it.  This is not yet implemented in GNU `m4'.
+     Unfortunately, this means it is not possible to mix builtins and
+     other text into a single macro; a helper macro is required.
+
+   * POSIX requires an application to exit with non-zero status if it
+     wrote an error message to stderr.  This has not yet been
+     consistently implemented for the various builtins that are
+     required to issue an error (such as `include' (*note Include::)
+     when a file is unreadable, `eval' (*note Eval::) when an argument
+     cannot be parsed, or using `m4exit' (*note M4exit::) with a
+     non-numeric argument).
+
+   * Some traditional implementations only allow reading standard input
+     once, but GNU `m4' correctly handles multiple instances of `-' on
+     the command line.
+
+   * POSIX requires `m4wrap' (*note M4wrap::) to act in FIFO (first-in,
+     first-out) order, but GNU `m4' currently uses LIFO order.
+     Furthermore, POSIX states that only the first argument to `m4wrap'
+     is saved for later evaluation, bug GNU `m4' saves and processes
+     all arguments, with output separated by spaces.
+
+     However, it is possible to emulate POSIX behavior by including the
+     file `m4-1.4.8/examples/wrapfifo.m4' from the distribution:
+
+          undivert(`wrapfifo.m4')dnl
+          =>dnl Redefine m4wrap to have FIFO semantics.
+          =>define(`_m4wrap_level', `0')dnl
+          =>define(`m4wrap',
+          =>`ifdef(`m4wrap'_m4wrap_level,
+          =>       `define(`m4wrap'_m4wrap_level,
+          =>               defn(`m4wrap'_m4wrap_level)`$1')',
+          =>       `builtin(`m4wrap', `define(`_m4wrap_level',
+          =>                                  incr(_m4wrap_level))dnl
+          =>m4wrap'_m4wrap_level)dnl
+          =>define(`m4wrap'_m4wrap_level, `$1')')')dnl
+          include(`wrapfifo.m4')
+          =>
+          m4wrap(`a`'m4wrap(`c
+          ', `d')')m4wrap(`b')
+          =>
+          ^D
+          =>abc
+
+   * POSIX requires that all builtins that require arguments, but are
+     called without arguments, behave as though empty strings had been
+     passed.  For example, `a`'define`'b' would expand to `ab'.  But
+     GNU `m4' ignores certain builtins if they have missing arguments,
+     giving `adefineb' for the above example.
+
+   * Traditional implementations handle `define(`f',`1')' (*note
+     Define::) by undefining the entire stack of previous definitions,
+     and if doing `undefine(`f')' first.  GNU `m4' replaces just the top
+     definition on the stack, as if doing `popdef(`f')' followed by
+     `pushdef(`f',`1')'.
+
+   * POSIX requires `syscmd' (*note Syscmd::) to evaluate command
+     output for macro expansion, but this appears to be a mistake in
+     POSIX since traditional implementations did not do this.  GNU `m4'
+     follows traditional behavior in `syscmd', and provides the
+     extension `esyscmd' that provides the POSIX semantics.
+
+   * At one point, POSIX required `changequote(ARG)' (*note
+     Changequote::) to use newline as the close quote, but this was a
+     bug, and the next version of POSIX is anticipated to state that
+     using empty strings or just one argument is unspecified.
+     Meanwhile, the GNU `m4' behavior of treating an empty end-quote
+     delimiter as `'' is not portable, as Solaris treats it as
+     repeating the start-quote delimiter, and BSD treats it as leaving
+     the previous end-quote delimiter unchanged.  For predictable
+     results, never call changequote with just one argument, or with
+     empty strings for arguments.
+
+   * At one point, POSIX required `changecom(ARG,)' (*note Changecom::)
+     to make it impossible to end a comment, but this is a bug, and the
+     next version of POSIX is anticipated to state that using empty
+     strings is unspecified.  Meanwhile, the GNU `m4' behavior of
+     treating an empty end-comment delimiter as newline is not
+     portable, as BSD treats it as leaving the previous end-comment
+     delimiter unchanged.  It is also impossible in BSD implementations
+     to disable comments, even though that is required by POSIX.  For
+     predictable results, never call changecom with empty strings for
+     arguments.
+
+   * Most implementations of `m4' give macros a higher precedence than
+     comments when parsing, meaning that if the start delimiter given to
+     `changecom' (*note Changecom::) starts with a macro name, comments
+     are effectively disabled.  POSIX does not specify what the
+     precedence is, so the GNU `m4' parser recognizes comments, then
+     macros, then quoted strings.
+
+   * Traditional implementations allow argument collection, but not
+     string and comment processing, to span file boundaries.  Thus, if
+     `a.m4' contains `len(', and `b.m4' contains `abc)', `m4 a.m4 b.m4'
+     outputs `3' with traditional `m4', but gives an error message that
+     the end of file was encountered inside a macro with GNU `m4'.  On
+     the other hand, traditional implementations do end of file
+     processing for files included with `include' or `sinclude' (*note
+     Include::), while GNU `m4' seamlessly integrates the content of
+     those files.  Thus `include(`a.m4')include(`b.m4')' will output
+     `3' instead of giving an error.
+
+   * Traditional `m4' treats `traceon' (*note Trace::) without
+     arguments as a global variable, independent of named macro tracing.
+     Also, once a macro is undefined, named tracing of that macro is
+     lost.  On the other hand, when GNU `m4' encounters `traceon'
+     without arguments, it turns tracing on for all existing
+     definitions at the time, but does not trace future definitions;
+     `traceoff' without arguments turns tracing off for all definitions
+     regardless of whether they were also traced by name; and tracing
+     by name, such as with `-tfoo' at the command line or
+     `traceon(`foo')' in the input, is an attribute that is preserved
+     even if the macro is currently undefined.
+
+   * POSIX requires `eval' (*note Eval::) to treat all operators with
+     the same precedence as C.  However, GNU `m4' currently follows the
+     traditional precedence of other `m4' implementations, where
+     bitwise and logical negation (`~' and `!') have lower precedence
+     than equality operators, rather than equal precedence with other
+     unary operators.  Use explicit parentheses to ensure proper
+     precedence.  As extensions to POSIX, GNU `m4' treats the shift
+     operators `<<' and `>>' as well-defined on signed integers (even
+     though they are not in C), and adds the exponentiation operator
+     `**'.
+
+   * POSIX requires `translit' (*note Translit::) to treat each
+     character of the second and third arguments literally, but GNU
+     `m4' treats `-' as a range operator.
+
+   * POSIX requires `m4' to honor the locale environment variables of
+     `LANG', `LC_ALL', `LC_CTYPE', `LC_MESSAGES', and `NLSPATH', but
+     this has not yet been implemented in GNU `m4'.
+
+   * POSIX states that only unquoted leading newlines and blanks (that
+     is, space and tab) are ignored when collecting macro arguments.
+     However, this appears to be a bug in POSIX, since most traditional
+     implementations also ignore all whitespace (formfeed, carriage
+     return, and vertical tab).  GNU `m4' follows tradition and ignores
+     all leading unquoted whitespace.
+
+
+File: m4.info,  Node: Other Incompatibilities,  Prev: Incompatibilities,  Up: Compatibility
+
+16.3 Other incompatibilities
+============================
+
+There are a few other incompatibilities between this implementation of
+`m4', and the System V version.
+
+   * GNU `m4' implements sync lines differently from System V `m4',
+     when text is being diverted.  GNU `m4' outputs the sync lines when
+     the text is being diverted, and System V `m4' when the diverted
+     text is being brought back.
+
+     The problem is which lines and file names should be attached to
+     text that is being, or has been, diverted.  System V `m4' regards
+     all the diverted text as being generated by the source line
+     containing the `undivert' call, whereas GNU `m4' regards the
+     diverted text as being generated at the time it is diverted.
+
+     The sync line option is used mostly when using `m4' as a front end
+     to a compiler.  If a diverted line causes a compiler error, the
+     error messages should most probably refer to the place where the
+     diversion were made, and not where it was inserted again.
+
+   * GNU `m4' makes no attempt at prohibiting self-referential
+     definitions like:
+
+          define(`x', `x')
+          =>
+          define(`x', `x ')
+          =>
+
+     There is nothing inherently wrong with defining `x' to return `x'.
+     The wrong thing is to expand `x' unquoted.  In `m4', one might
+     use macros to hold strings, as we do for variables in other
+     programming languages, further checking them with:
+
+          ifelse(defn(`HOLDER'), `VALUE', ...)
+
+     In cases like this one, an interdiction for a macro to hold its own
+     name would be a useless limitation.  Of course, this leaves more
+     rope for the GNU `m4' user to hang himself!  Rescanning hangs may
+     be avoided through careful programming, a little like for endless
+     loops in traditional programming languages.
+
+
+File: m4.info,  Node: Answers,  Next: Copying This Manual,  Prev: Compatibility,  Up: Top
+
+17 Correct version of some examples
+***********************************
+
+Some of the examples in this manuals are buggy or not very robust, for
+demonstration purposes.  Improved versions of these composite macros are
+presented here.
+
+* Menu:
+
+* Improved exch::               Solution for `exch'
+* Improved forloop::            Solution for `forloop'
+* Improved foreach::            Solution for `foreach'
+* Improved cleardivert::        Solution for `cleardivert'
+* Improved fatal_error::        Solution for `fatal_error'
+
+
+File: m4.info,  Node: Improved exch,  Next: Improved forloop,  Up: Answers
+
+17.1 Solution for `exch'
+========================
+
+The `exch' macro (*note Arguments::) as presented requires clients to
+double quote their arguments.  A nicer definition, which lets clients
+follow the rule of thumb of one level of quoting per level of
+parentheses, involves adding quotes in the definition of `exch', as
+follows:
+
+     define(`exch', ``$2', `$1'')
+     =>
+     define(exch(`expansion text', `macro'))
+     =>
+     macro
+     =>expansion text
+
+
+File: m4.info,  Node: Improved forloop,  Next: Improved foreach,  Prev: Improved exch,  Up: Answers
+
+17.2 Solution for `forloop'
+===========================
+
+The `forloop' macro (*note Forloop::) as presented earlier can go into
+an infinite loop if given an iterator that is not parsed as a macro
+name.  It does not do any sanity checking on its numeric bounds, and
+only permits decimal numbers for bounds.  Here is an improved version,
+shipped as `m4-1.4.8/examples/forloop2.m4'; this version also optimizes
+based on the fact that the starting bound does not need to be passed to
+the helper `_forloop'.
+
+     undivert(`forloop2.m4')dnl
+     =>divert(`-1')
+     =># forloop(var, from, to, stmt) - improved version:
+     =>#   works even if VAR is not a strict macro name
+     =>#   performs sanity check that FROM is larger than TO
+     =>#   allows complex numerical expressions in TO and FROM
+     =>define(`forloop', `ifelse(eval(`($3) >= ($2)'), `1',
+     =>  `pushdef(`$1', eval(`$2'))_forloop(`$1',
+     =>    eval(`$3'), `$4')popdef(`$1')')')
+     =>define(`_forloop',
+     =>  `$3`'ifelse(indir(`$1'), `$2', `',
+     =>    `define(`$1', incr(indir(`$1')))$0($@)')')
+     =>divert`'dnl
+     include(`forloop2.m4')
+     =>
+     forloop(`i', `2', `1', `no iteration occurs')
+     =>
+     forloop(`', `1', `2', ` odd iterator name')
+     => odd iterator name odd iterator name
+     forloop(`i', `5 + 5', `0xc', ` 0x`'eval(i, `16')')
+     => 0xa 0xb 0xc
+     forloop(`i', `a', `b', `non-numeric bounds')
+     error-->m4:stdin:6: bad expression in eval (bad input): (b) >= (a)
+     =>
+
+   Of course, it is possible to make even more improvements, such as
+adding an optional step argument, or allowing iteration through
+descending sequences.  GNU Autoconf provides some of these additional
+bells and whistles in its `m4_for' macro.
+
+
+File: m4.info,  Node: Improved foreach,  Next: Improved cleardivert,  Prev: Improved forloop,  Up: Answers
+
+17.3 Solution for `foreach'
+===========================
+
+The `foreach' and `foreachq' macros (*note Foreach::) as presented
+earlier each have flaws.  First, we will examine and fix the quadratic
+behavior of `foreachq':
+
+     include(`foreachq.m4')
+     =>
+     traceon(`shift')debugmode(`aq')
+     =>
+     foreachq(`x', ``1', `2', `3', `4'', `x
+     ')dnl
+     =>1
+     error-->m4trace: -3- shift(`1', `2', `3', `4')
+     error-->m4trace: -2- shift(`1', `2', `3', `4')
+     =>2
+     error-->m4trace: -4- shift(`1', `2', `3', `4')
+     error-->m4trace: -3- shift(`2', `3', `4')
+     error-->m4trace: -3- shift(`1', `2', `3', `4')
+     error-->m4trace: -2- shift(`2', `3', `4')
+     =>3
+     error-->m4trace: -5- shift(`1', `2', `3', `4')
+     error-->m4trace: -4- shift(`2', `3', `4')
+     error-->m4trace: -3- shift(`3', `4')
+     error-->m4trace: -4- shift(`1', `2', `3', `4')
+     error-->m4trace: -3- shift(`2', `3', `4')
+     error-->m4trace: -2- shift(`3', `4')
+     =>4
+     error-->m4trace: -6- shift(`1', `2', `3', `4')
+     error-->m4trace: -5- shift(`2', `3', `4')
+     error-->m4trace: -4- shift(`3', `4')
+     error-->m4trace: -3- shift(`4')
+
+   Each successive iteration was adding more quoted `shift'
+invocations, and the entire list contents were passing through every
+iteration.  In general, when recursing, it is a good idea to make the
+recursion use fewer arguments, rather than adding additional quoted
+uses of `shift'.  By doing so, `m4' uses less memory, invokes fewer
+macros, is less likely to run into machine limits, and most
+importantly, performs faster.  The fixed version of `foreachq' can be
+found in `m4-1.4.8/examples/foreachq2.m4':
+
+     include(`foreachq2.m4')
+     =>
+     undivert(`foreachq2.m4')dnl
+     =>include(`quote.m4')dnl
+     =>divert(`-1')
+     =># foreachq(x, `item_1, item_2, ..., item_n', stmt)
+     =>#   quoted list, improved version
+     =>define(`foreachq', `pushdef(`$1')_foreachq($@)popdef(`$1')')
+     =>define(`_arg1q', ``$1'')
+     =>define(`_rest', `ifelse(`$#', `1', `', `dquote(shift($@))')')
+     =>define(`_foreachq', `ifelse(`$2', `', `',
+     =>  `define(`$1', _arg1q($2))$3`'$0(`$1', _rest($2), `$3')')')
+     =>divert`'dnl
+     traceon(`shift')debugmode(`aq')
+     =>
+     foreachq(`x', ``1', `2', `3', `4'', `x
+     ')dnl
+     =>1
+     error-->m4trace: -3- shift(`1', `2', `3', `4')
+     =>2
+     error-->m4trace: -3- shift(`2', `3', `4')
+     =>3
+     error-->m4trace: -3- shift(`3', `4')
+     =>4
+
+   Note that the fixed version calls unquoted helper macros in
+`_foreachq' to trim elements immediately; those helper macros in turn
+must re-supply the layer of quotes lost in the macro invocation.
+Contrast the use of `_arg1q', which quotes the first list element, with
+`_arg1' of the earlier implementation that returned the first list
+element directly.
+
+   For a different approach, the improved version of `foreach',
+available in `m4-1.4.8/examples/foreach2.m4', simply overquotes the
+arguments to `_foreach' to begin with, using `dquote_elt'.  Then
+`_foreach' can just use `_arg1' to remove the extra layer of quoting
+that was added up front:
+
+     include(`foreach2.m4')
+     =>
+     undivert(`foreach2.m4')dnl
+     =>include(`quote.m4')dnl
+     =>divert(`-1')
+     =># foreach(x, (item_1, item_2, ..., item_n), stmt)
+     =>#   parenthesized list, improved version
+     =>define(`foreach', `pushdef(`$1')_foreach(`$1',
+     =>  (dquote(dquote_elt$2)), `$3')popdef(`$1')')
+     =>define(`_arg1', `$1')
+     =>define(`_foreach', `ifelse(`$2', `(`')', `',
+     =>  `define(`$1', _arg1$2)$3`'$0(`$1', (dquote(shift$2)), `$3')')')
+     =>divert`'dnl
+     traceon(`shift')debugmode(`aq')
+     =>
+     foreach(`x', `(`1', `2', `3', `4')', `x
+     ')dnl
+     error-->m4trace: -4- shift(`1', `2', `3', `4')
+     error-->m4trace: -4- shift(`2', `3', `4')
+     error-->m4trace: -4- shift(`3', `4')
+     =>1
+     error-->m4trace: -3- shift(``1'', ``2'', ``3'', ``4'')
+     =>2
+     error-->m4trace: -3- shift(``2'', ``3'', ``4'')
+     =>3
+     error-->m4trace: -3- shift(``3'', ``4'')
+     =>4
+     error-->m4trace: -3- shift(``4'')
+
+   In summary, recursion over list elements is trickier than it
+appeared at first glance, but provides a powerful idiom within `m4'
+processing.  As a final demonstration, both list styles are now able to
+handle several scenarios that would wreak havoc on the original
+implementations.  This points out one other difference between the two
+list styles.  `foreach' evaluates unquoted list elements only once, in
+preparation for calling `_foreach'.  But `foreachq' evaluates unquoted
+list elements twice while visiting the first list element, once in
+`_arg1q' and once in `_rest'.  When deciding which list style to use,
+one must take into account whether repeating the side effects of
+unquoted list elements will have any detrimental effects.
+
+     include(`foreach2.m4')
+     =>
+     include(`foreachq2.m4')
+     =>
+     dnl 0-element list:
+     foreach(`x', `', `<x>') / foreachq(`x', `', `<x>')
+     => / 
+     dnl 1-element list of empty element
+     foreach(`x', `()', `<x>') / foreachq(`x', ``'', `<x>')
+     =><> / <>
+     dnl 2-element list of empty elements
+     foreach(`x', `(`',`')', `<x>') / foreachq(`x', ``',`'', `<x>')
+     =><><> / <><>
+     dnl 1-element list of a comma
+     foreach(`x', `(`,')', `<x>') / foreachq(`x', ``,'', `<x>')
+     =><,> / <,>
+     dnl 2-element list of unbalanced parentheses
+     foreach(`x', `(`(', `)')', `<x>') / foreachq(`x', ``(', `)'', `<x>')
+     =><(><)> / <(><)>
+     define(`active', `ACT, IVE')
+     =>
+     traceon(`active')
+     =>
+     dnl list of unquoted macros; expansion occurs before recursion
+     foreach(`x', `(active, active)', `<x>
+     ')dnl
+     error-->m4trace: -4- active -> `ACT, IVE'
+     error-->m4trace: -4- active -> `ACT, IVE'
+     =><ACT>
+     =><IVE>
+     =><ACT>
+     =><IVE>
+     foreachq(`x', `active, active', `<x>
+     ')dnl
+     error-->m4trace: -3- active -> `ACT, IVE'
+     error-->m4trace: -3- active -> `ACT, IVE'
+     =><ACT>
+     error-->m4trace: -3- active -> `ACT, IVE'
+     error-->m4trace: -3- active -> `ACT, IVE'
+     =><IVE>
+     =><ACT>
+     =><IVE>
+     dnl list of quoted macros; expansion occurs during recursion
+     foreach(`x', `(`active', `active')', `<x>
+     ')dnl
+     error-->m4trace: -1- active -> `ACT, IVE'
+     =><ACT, IVE>
+     error-->m4trace: -1- active -> `ACT, IVE'
+     =><ACT, IVE>
+     foreachq(`x', ``active', `active'', `<x>
+     ')dnl
+     error-->m4trace: -1- active -> `ACT, IVE'
+     =><ACT, IVE>
+     error-->m4trace: -1- active -> `ACT, IVE'
+     =><ACT, IVE>
+     dnl list of double-quoted macro names; no expansion
+     foreach(`x', `(``active'', ``active'')', `<x>
+     ')dnl
+     =><active>
+     =><active>
+     foreachq(`x', ```active'', ``active''', `<x>
+     ')dnl
+     =><active>
+     =><active>
+
+
+File: m4.info,  Node: Improved cleardivert,  Next: Improved fatal_error,  Prev: Improved foreach,  Up: Answers
+
+17.4 Solution for `cleardivert'
+===============================
+
+The `cleardivert' macro (*note Cleardivert::) cannot, as it stands, be
+called without arguments to clear all pending diversions.  That is
+because using undivert with an empty string for an argument is different
+than using it with no arguments at all.  Compare the earlier definition
+with one that takes the number of arguments into account:
+
+     define(`cleardivert',
+       `pushdef(`_n', divnum)divert(`-1')undivert($@)divert(_n)popdef(`_n')')
+     =>
+     divert(`1')one
+     divert
+     =>
+     cleardivert
+     =>
+     undivert
+     =>one
+     =>
+     define(`cleardivert',
+       `pushdef(`_num', divnum)divert(`-1')ifelse(`$#', `0',
+         `undivert`'', `undivert($@)')divert(_num)popdef(`_num')')
+     =>
+     divert(`2')two
+     divert
+     =>
+     cleardivert
+     =>
+     undivert
+     =>
+
+
+File: m4.info,  Node: Improved fatal_error,  Prev: Improved cleardivert,  Up: Answers
+
+17.5 Solution for `fatal_error'
+===============================
+
+The `fatal_error' macro (*note M4exit::) is not robust to versions of
+GNU M4 earlier than 1.4.8, where invoking `__file__' (*note Location::)
+inside `m4wrap' would result in an empty string, and `__line__'
+resulted in `0' even though all files start at line 1.  Furthermore,
+versions earlier than 1.4.6 did not support the `__program__' macro.
+If you want `fatal_error' to work across the entire 1.4.x release
+series, a better implementation would be:
+
+     define(`fatal_error',
+       `errprint(ifdef(`__program__', `__program__', ``m4'')'dnl
+     `:ifelse(__line__, `0', `',
+         `__file__:__line__:')` fatal error: $*
+     ')m4exit(`1')')
+     =>
+     m4wrap(`divnum(`demo of internal message')
+     fatal_error(`inside wrapped text')')
+     =>
+     ^D
+     error-->m4:stdin:6: Warning: excess arguments to builtin `divnum' ignored
+     =>0
+     error-->m4:stdin:6: fatal error: inside wrapped text
+
+
+File: m4.info,  Node: Copying This Manual,  Next: Indices,  Prev: Answers,  Up: Top
+
+Appendix A How to make copies of this manual
+********************************************
+
+* Menu:
+
+* GNU Free Documentation License::  License for copying this manual
+
+
+File: m4.info,  Node: GNU Free Documentation License,  Up: Copying This Manual
+
+A.1 GNU Free Documentation License
+==================================
+
+                      Version 1.2, November 2002
+
+     Copyright (C) 2000,2001,2002 Free Software Foundation, Inc.
+     51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
+
+     Everyone is permitted to copy and distribute verbatim copies
+     of this license document, but changing it is not allowed.
+
+  0. PREAMBLE
+
+     The purpose of this License is to make a manual, textbook, or other
+     functional and useful document "free" in the sense of freedom: to
+     assure everyone the effective freedom to copy and redistribute it,
+     with or without modifying it, either commercially or
+     noncommercially.  Secondarily, this License preserves for the
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+     being considered responsible for modifications made by others.
+
+     This License is a kind of "copyleft", which means that derivative
+     works of the document must themselves be free in the same sense.
+     It complements the GNU General Public License, which is a copyleft
+     license designed for free software.
+
+     We have designed this License in order to use it for manuals for
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+     free program should come with manuals providing the same freedoms
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+     We recommend this License principally for works whose purpose is
+     instruction or reference.
+
+  1. APPLICABILITY AND DEFINITIONS
+
+     This License applies to any manual or other work, in any medium,
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+     A "Modified Version" of the Document means any work containing the
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+
+     The Document may include Warranty Disclaimers next to the notice
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+     this License, but only as regards disclaiming warranties: any other
+     implication that these Warranty Disclaimers may have is void and
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+
+  2. VERBATIM COPYING
+
+     You may copy and distribute the Document in any medium, either
+     commercially or noncommercially, provided that this License, the
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+     add no other conditions whatsoever to those of this License.  You
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+     or further copying of the copies you make or distribute.  However,
+     you may accept compensation in exchange for copies.  If you
+     distribute a large enough number of copies you must also follow
+     the conditions in section 3.
+
+     You may also lend copies, under the same conditions stated above,
+     and you may publicly display copies.
+
+  3. COPYING IN QUANTITY
+
+     If you publish printed copies (or copies in media that commonly
+     have printed covers) of the Document, numbering more than 100, and
+     the Document's license notice requires Cover Texts, you must
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+     satisfy these conditions, can be treated as verbatim copying in
+     other respects.
+
+     If the required texts for either cover are too voluminous to fit
+     legibly, you should put the first ones listed (as many as fit
+     reasonably) on the actual cover, and continue the rest onto
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+
+     If you publish or distribute Opaque copies of the Document
+     numbering more than 100, you must either include a
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+     state in or with each Opaque copy a computer-network location from
+     which the general network-using public has access to download
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+     begin distribution of Opaque copies in quantity, to ensure that
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+     location until at least one year after the last time you
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+
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+
+  4. MODIFICATIONS
+
+     You may copy and distribute a Modified Version of the Document
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+
+       A. Use in the Title Page (and on the covers, if any) a title
+          distinct from that of the Document, and from those of
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+          same title as a previous version if the original publisher of
+          that version gives permission.
+
+       B. List on the Title Page, as authors, one or more persons or
+          entities responsible for authorship of the modifications in
+          the Modified Version, together with at least five of the
+          principal authors of the Document (all of its principal
+          authors, if it has fewer than five), unless they release you
+          from this requirement.
+
+       C. State on the Title page the name of the publisher of the
+          Modified Version, as the publisher.
+
+       D. Preserve all the copyright notices of the Document.
+
+       E. Add an appropriate copyright notice for your modifications
+          adjacent to the other copyright notices.
+
+       F. Include, immediately after the copyright notices, a license
+          notice giving the public permission to use the Modified
+          Version under the terms of this License, in the form shown in
+          the Addendum below.
+
+       G. Preserve in that license notice the full lists of Invariant
+          Sections and required Cover Texts given in the Document's
+          license notice.
+
+       H. Include an unaltered copy of this License.
+
+       I. Preserve the section Entitled "History", Preserve its Title,
+          and add to it an item stating at least the title, year, new
+          authors, and publisher of the Modified Version as given on
+          the Title Page.  If there is no section Entitled "History" in
+          the Document, create one stating the title, year, authors,
+          and publisher of the Document as given on its Title Page,
+          then add an item describing the Modified Version as stated in
+          the previous sentence.
+
+       J. Preserve the network location, if any, given in the Document
+          for public access to a Transparent copy of the Document, and
+          likewise the network locations given in the Document for
+          previous versions it was based on.  These may be placed in
+          the "History" section.  You may omit a network location for a
+          work that was published at least four years before the
+          Document itself, or if the original publisher of the version
+          it refers to gives permission.
+
+       K. For any section Entitled "Acknowledgements" or "Dedications",
+          Preserve the Title of the section, and preserve in the
+          section all the substance and tone of each of the contributor
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+
+       L. Preserve all the Invariant Sections of the Document,
+          unaltered in their text and in their titles.  Section numbers
+          or the equivalent are not considered part of the section
+          titles.
+
+       M. Delete any section Entitled "Endorsements".  Such a section
+          may not be included in the Modified Version.
+
+       N. Do not retitle any existing section to be Entitled
+          "Endorsements" or to conflict in title with any Invariant
+          Section.
+
+       O. Preserve any Warranty Disclaimers.
+
+     If the Modified Version includes new front-matter sections or
+     appendices that qualify as Secondary Sections and contain no
+     material copied from the Document, you may at your option
+     designate some or all of these sections as invariant.  To do this,
+     add their titles to the list of Invariant Sections in the Modified
+     Version's license notice.  These titles must be distinct from any
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+
+     You may add a section Entitled "Endorsements", provided it contains
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+
+     You may add a passage of up to five words as a Front-Cover Text,
+     and a passage of up to 25 words as a Back-Cover Text, to the end
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+     passage of Front-Cover Text and one of Back-Cover Text may be
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+
+     The author(s) and publisher(s) of the Document do not by this
+     License give permission to use their names for publicity for or to
+     assert or imply endorsement of any Modified Version.
+
+  5. COMBINING DOCUMENTS
+
+     You may combine the Document with other documents released under
+     this License, under the terms defined in section 4 above for
+     modified versions, provided that you include in the combination
+     all of the Invariant Sections of all of the original documents,
+     unmodified, and list them all as Invariant Sections of your
+     combined work in its license notice, and that you preserve all
+     their Warranty Disclaimers.
+
+     The combined work need only contain one copy of this License, and
+     multiple identical Invariant Sections may be replaced with a single
+     copy.  If there are multiple Invariant Sections with the same name
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+     by adding at the end of it, in parentheses, the name of the
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+     combined work.
+
+     In the combination, you must combine any sections Entitled
+     "History" in the various original documents, forming one section
+     Entitled "History"; likewise combine any sections Entitled
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+     must delete all sections Entitled "Endorsements."
+
+  6. COLLECTIONS OF DOCUMENTS
+
+     You may make a collection consisting of the Document and other
+     documents released under this License, and replace the individual
+     copies of this License in the various documents with a single copy
+     that is included in the collection, provided that you follow the
+     rules of this License for verbatim copying of each of the
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+
+     You may extract a single document from such a collection, and
+     distribute it individually under this License, provided you insert
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+     that document.
+
+  7. AGGREGATION WITH INDEPENDENT WORKS
+
+     A compilation of the Document or its derivatives with other
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+     a storage or distribution medium, is called an "aggregate" if the
+     copyright resulting from the compilation is not used to limit the
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+
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+
+  8. TRANSLATION
+
+     Translation is considered a kind of modification, so you may
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+
+     If a section in the Document is Entitled "Acknowledgements",
+     "Dedications", or "History", the requirement (section 4) to
+     Preserve its Title (section 1) will typically require changing the
+     actual title.
+
+  9. TERMINATION
+
+     You may not copy, modify, sublicense, or distribute the Document
+     except as expressly provided for under this License.  Any other
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+     void, and will automatically terminate your rights under this
+     License.  However, parties who have received copies, or rights,
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+     terminated so long as such parties remain in full compliance.
+
+ 10. FUTURE REVISIONS OF THIS LICENSE
+
+     The Free Software Foundation may publish new, revised versions of
+     the GNU Free Documentation License from time to time.  Such new
+     versions will be similar in spirit to the present version, but may
+     differ in detail to address new problems or concerns.  See
+     `http://www.gnu.org/copyleft/'.
+
+     Each version of the License is given a distinguishing version
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+     published (not as a draft) by the Free Software Foundation.  If
+     the Document does not specify a version number of this License,
+     you may choose any version ever published (not as a draft) by the
+     Free Software Foundation.
+
+ADDENDUM: How to use this License for your documents
+====================================================
+
+To use this License in a document you have written, include a copy of
+the License in the document and put the following copyright and license
+notices just after the title page:
+
+       Copyright (C)  YEAR  YOUR NAME.
+       Permission is granted to copy, distribute and/or modify this document
+       under the terms of the GNU Free Documentation License, Version 1.2
+       or any later version published by the Free Software Foundation;
+       with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
+       Texts.  A copy of the license is included in the section entitled ``GNU
+       Free Documentation License''.
+
+   If you have Invariant Sections, Front-Cover Texts and Back-Cover
+Texts, replace the "with...Texts." line with this:
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+         with the Invariant Sections being LIST THEIR TITLES, with
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+         being LIST.
+
+   If you have Invariant Sections without Cover Texts, or some other
+combination of the three, merge those two alternatives to suit the
+situation.
+
+   If your document contains nontrivial examples of program code, we
+recommend releasing these examples in parallel under your choice of
+free software license, such as the GNU General Public License, to
+permit their use in free software.
+
+
+File: m4.info,  Node: Indices,  Prev: Copying This Manual,  Up: Top
+
+Appendix B Indices of concepts and macros
+*****************************************
+
+* Menu:
+
+* Concept index::               Index for many concepts
+* Macro index::                 Index for all `m4' macros
+
+
+File: m4.info,  Node: Concept index,  Next: Macro index,  Up: Indices
+
+B.1 Index for many concepts
+===========================
+
+[index]
+* Menu:
+
+* arguments to macros:                   Macro Arguments.      (line  6)
+* Arguments to macros:                   Arguments.            (line  6)
+* arguments to macros, special:          Pseudo Arguments.     (line  6)
+* arguments, quoted macro:               Quoting Arguments.    (line  6)
+* arithmetic:                            Arithmetic.           (line  6)
+* arrays:                                Define.               (line 52)
+* builtins, indirect call of:            Builtin.              (line  6)
+* call of builtins, indirect:            Builtin.              (line  6)
+* call of macros, indirect:              Indir.                (line  6)
+* changing comment delimiters:           Changecom.            (line  6)
+* changing the quote delimiters:         Changequote.          (line  6)
+* characters, translating:               Translit.             (line  6)
+* command line, file names on the:       Command line files.   (line  6)
+* command line, macro definitions on the: Preprocessor features.
+                                                               (line  6)
+* command line, options:                 Invoking m4.          (line 10)
+* commands, exit status from shell:      Sysval.               (line  6)
+* commands, running shell:               Shell commands.       (line  6)
+* commands, running UNIX:                Shell commands.       (line  6)
+* comment delimiters, changing:          Changecom.            (line  6)
+* comments:                              Comments.             (line  6)
+* comments, copied to output:            Changecom.            (line 29)
+* comparing strings:                     Ifelse.               (line  6)
+* compatibility:                         Compatibility.        (line  6)
+* conditionals:                          Ifdef.                (line  6)
+* controlling debugging output:          Debug Levels.         (line  6)
+* counting loops:                        Forloop.              (line  6)
+* debugging output, controlling:         Debug Levels.         (line  6)
+* debugging output, saving:              Debug Output.         (line  6)
+* decrement operator:                    Incr.                 (line  6)
+* defining new macros:                   Definitions.          (line  6)
+* definitions, displaying macro:         Dumpdef.              (line  6)
+* deleting macros:                       Undefine.             (line  6)
+* deleting whitespace in input:          Dnl.                  (line  6)
+* discarding diverted text:              Cleardivert.          (line  6)
+* displaying macro definitions:          Dumpdef.              (line  6)
+* diversion numbers:                     Divnum.               (line  6)
+* diverted text, discarding:             Cleardivert.          (line  6)
+* diverting output to files:             Divert.               (line  6)
+* dumping into frozen file:              Using frozen files.   (line  6)
+* error messages, printing:              Errprint.             (line  6)
+* evaluation, of integer expressions:    Eval.                 (line  6)
+* executing shell commands:              Shell commands.       (line  6)
+* executing UNIX commands:               Shell commands.       (line  6)
+* exit status from shell commands:       Sysval.               (line  6)
+* exiting from m4:                       M4exit.               (line  6)
+* expansion of macros:                   Macro expansion.      (line  6)
+* expansion, tracing macro:              Trace.                (line  6)
+* expressions, evaluation of integer:    Eval.                 (line  6)
+* extracting substrings:                 Substr.               (line  6)
+* fast loading of frozen files:          Using frozen files.   (line  6)
+* FDL, GNU Free Documentation License:   GNU Free Documentation License.
+                                                               (line  6)
+* file format, frozen file:              Frozen file format.   (line  6)
+* file inclusion <1>:                    Undivert.             (line 81)
+* file inclusion:                        File Inclusion.       (line  6)
+* file names, on the command line:       Command line files.   (line  6)
+* files, diverting output to:            Divert.               (line  6)
+* files, names of temporary:             Mkstemp.              (line  6)
+* for each loops:                        Foreach.              (line  6)
+* for loops:                             Forloop.              (line  6)
+* formatted output:                      Format.               (line  6)
+* frozen file format:                    Frozen file format.   (line  6)
+* frozen files for fast loading:         Using frozen files.   (line  6)
+* GNU extensions <1>:                    Indir.                (line  6)
+* GNU extensions <2>:                    Patsubst.             (line  6)
+* GNU extensions <3>:                    Extensions.           (line  6)
+* GNU extensions <4>:                    Regexp.               (line  6)
+* GNU extensions <5>:                    Using frozen files.   (line  6)
+* GNU extensions <6>:                    Format.               (line  6)
+* GNU extensions <7>:                    Undivert.             (line 81)
+* GNU extensions <8>:                    Divert.               (line 54)
+* GNU extensions <9>:                    Search Path.          (line  6)
+* GNU extensions <10>:                   Define.               (line 41)
+* GNU extensions <11>:                   Arguments.            (line 32)
+* GNU extensions <12>:                   Esyscmd.              (line  6)
+* GNU extensions <13>:                   Debug Output.         (line  6)
+* GNU extensions <14>:                   Mkstemp.              (line 52)
+* GNU extensions <15>:                   Builtin.              (line  6)
+* GNU extensions:                        Debug Levels.         (line 59)
+* included files, search path for:       Search Path.          (line  6)
+* inclusion, of files <1>:               Undivert.             (line 81)
+* inclusion, of files:                   File Inclusion.       (line  6)
+* increment operator:                    Incr.                 (line  6)
+* indirect call of builtins:             Builtin.              (line  6)
+* indirect call of macros:               Indir.                (line  6)
+* initialization, frozen states:         Using frozen files.   (line  6)
+* input tokens:                          Syntax.               (line  6)
+* input, saving:                         M4wrap.               (line  6)
+* integer arithmetic:                    Arithmetic.           (line  6)
+* integer expression evaluation:         Eval.                 (line  6)
+* iterating over lists:                  Foreach.              (line  6)
+* length of strings:                     Len.                  (line  6)
+* lexical structure of words:            Changeword.           (line  6)
+* License:                               Copying This Manual.  (line  6)
+* local variables:                       Pushdef.              (line 75)
+* loops:                                 Shift.                (line 10)
+* loops, counting:                       Forloop.              (line  6)
+* loops, list iteration:                 Foreach.              (line  6)
+* macro definitions, on the command line: Preprocessor features.
+                                                               (line  6)
+* macro expansion, tracing:              Trace.                (line  6)
+* macro invocation:                      Invocation.           (line  6)
+* macros, arguments to <1>:              Macro Arguments.      (line  6)
+* macros, arguments to:                  Arguments.            (line  6)
+* macros, displaying definitions:        Dumpdef.              (line  6)
+* macros, expansion of:                  Macro expansion.      (line  6)
+* macros, how to define new:             Definitions.          (line  6)
+* macros, how to delete:                 Undefine.             (line  6)
+* macros, how to rename:                 Defn.                 (line  6)
+* macros, indirect call of:              Indir.                (line  6)
+* macros, quoted arguments to:           Quoting Arguments.    (line  6)
+* macros, recursive:                     Shift.                (line  6)
+* macros, special arguments to:          Pseudo Arguments.     (line  6)
+* macros, temporary redefinition of:     Pushdef.              (line  6)
+* messages, printing error:              Errprint.             (line  6)
+* multibranches:                         Ifelse.               (line 66)
+* names:                                 Names.                (line  6)
+* options, command line:                 Invoking m4.          (line 10)
+* output, diverting to files:            Divert.               (line  6)
+* output, formatted:                     Format.               (line  6)
+* output, saving debugging:              Debug Output.         (line  6)
+* pattern substitution:                  Patsubst.             (line  6)
+* platform macro:                        Platform macros.      (line 31)
+* platform macros:                       Platform macros.      (line  6)
+* POSIXLY_CORRECT:                       Invoking m4.          (line 10)
+* printing error messages:               Errprint.             (line  6)
+* quote delimiters, changing the:        Changequote.          (line  6)
+* quoted macro arguments:                Quoting Arguments.    (line  6)
+* quoted string:                         Quoted strings.       (line  6)
+* recursive macros:                      Shift.                (line  6)
+* redefinition of macros, temporary:     Pushdef.              (line  6)
+* regular expressions <1>:               Patsubst.             (line  6)
+* regular expressions:                   Regexp.               (line  6)
+* reloading a frozen file:               Using frozen files.   (line  6)
+* renaming macros:                       Defn.                 (line  6)
+* running shell commands:                Shell commands.       (line  6)
+* running UNIX commands:                 Shell commands.       (line  6)
+* saving debugging output:               Debug Output.         (line  6)
+* saving input:                          M4wrap.               (line  6)
+* search path for included files:        Search Path.          (line  6)
+* shell commands, exit status from:      Sysval.               (line  6)
+* shell commands, running:               Shell commands.       (line  6)
+* special arguments to macros:           Pseudo Arguments.     (line  6)
+* status of shell commands:              Sysval.               (line  6)
+* status, setting m4 exit:               M4exit.               (line  6)
+* strings, length of:                    Len.                  (line  6)
+* substitution by regular expression:    Patsubst.             (line  6)
+* substrings, extracting:                Substr.               (line  6)
+* temporary file names:                  Mkstemp.              (line  6)
+* temporary redefinition of macros:      Pushdef.              (line  6)
+* tokens:                                Syntax.               (line  6)
+* tracing macro expansion:               Trace.                (line  6)
+* translating characters:                Translit.             (line  6)
+* undefining macros:                     Undefine.             (line  6)
+* UNIX commands, exit status from:       Sysval.               (line  6)
+* UNIX commands, running:                Shell commands.       (line  6)
+* variables, local:                      Pushdef.              (line 75)
+* words, lexical structure of:           Changeword.           (line  6)
+
+
+File: m4.info,  Node: Macro index,  Prev: Concept index,  Up: Indices
+
+B.2 Index for all `m4' macros
+=============================
+
+References are exclusively to the places where a builtin is introduced
+the first time.
+
+[index]
+* Menu:
+
+* __file__:                              Location.             (line 10)
+* __gnu__:                               Platform macros.      (line 12)
+* __line__:                              Location.             (line 11)
+* __os2__:                               Platform macros.      (line 13)
+* __program__:                           Location.             (line 12)
+* __unix__:                              Platform macros.      (line 15)
+* __windows__:                           Platform macros.      (line 17)
+* builtin:                               Builtin.              (line  9)
+* capitalize:                            Patsubst.             (line 55)
+* changecom:                             Changecom.            (line 10)
+* changequote:                           Changequote.          (line 10)
+* changeword:                            Changeword.           (line 23)
+* cleardivert:                           Cleardivert.          (line 26)
+* debugfile:                             Debug Output.         (line 11)
+* debugmode:                             Debug Levels.         (line 63)
+* decr:                                  Incr.                 (line 11)
+* define:                                Define.               (line 10)
+* defn:                                  Defn.                 (line 10)
+* divert:                                Divert.               (line  9)
+* divnum:                                Divnum.               (line  9)
+* dnl:                                   Dnl.                  (line  9)
+* downcase:                              Patsubst.             (line 54)
+* dquote:                                Shift.                (line 53)
+* dquote_elt:                            Shift.                (line 54)
+* dumpdef:                               Dumpdef.              (line 10)
+* errprint:                              Errprint.             (line  9)
+* esyscmd:                               Esyscmd.              (line  9)
+* eval:                                  Eval.                 (line  9)
+* example:                               Manual.               (line 32)
+* fatal_error:                           M4exit.               (line 25)
+* foreach:                               Foreach.              (line  9)
+* foreachq:                              Foreach.              (line 10)
+* forloop:                               Forloop.              (line  9)
+* format:                                Format.               (line  9)
+* ifdef:                                 Ifdef.                (line 10)
+* ifelse:                                Ifelse.               (line 12)
+* include:                               Include.              (line  9)
+* incr:                                  Incr.                 (line 10)
+* index:                                 Index macro.          (line  9)
+* indir:                                 Indir.                (line  9)
+* len:                                   Len.                  (line  9)
+* m4exit:                                M4exit.               (line 10)
+* m4wrap:                                M4wrap.               (line 14)
+* maketemp:                              Mkstemp.              (line 12)
+* mkstemp:                               Mkstemp.              (line 11)
+* os2:                                   Platform macros.      (line 14)
+* patsubst:                              Patsubst.             (line  9)
+* popdef:                                Pushdef.              (line 12)
+* pushdef:                               Pushdef.              (line 11)
+* quote:                                 Shift.                (line 52)
+* regexp:                                Regexp.               (line  9)
+* reverse:                               Shift.                (line 32)
+* shift:                                 Shift.                (line 17)
+* sinclude:                              Include.              (line 10)
+* substr:                                Substr.               (line  9)
+* syscmd:                                Syscmd.               (line  9)
+* sysval:                                Sysval.               (line  9)
+* traceoff:                              Trace.                (line 11)
+* traceon:                               Trace.                (line 10)
+* translit:                              Translit.             (line  9)
+* undefine:                              Undefine.             (line  9)
+* undivert:                              Undivert.             (line  9)
+* unix:                                  Platform macros.      (line 16)
+* upcase:                                Patsubst.             (line 53)
+* windows:                               Platform macros.      (line 18)
+
+
+
+Tag Table:
+Node: Top840
+Node: Preliminaries9196
+Node: Intro9882
+Node: History11514
+Node: Bugs14146
+Node: Manual15408
+Node: Invoking m418340
+Node: Operation modes20488
+Node: Preprocessor features22199
+Node: Limits control24701
+Node: Frozen state27637
+Node: Debugging options28436
+Node: Command line files30175
+Node: Syntax31538
+Node: Names32539
+Node: Quoted strings33001
+Node: Comments33650
+Node: Other tokens34517
+Node: Input processing35095
+Node: Macros36982
+Node: Invocation37476
+Node: Inhibiting Invocation38277
+Node: Macro Arguments41848
+Node: Quoting Arguments44539
+Node: Macro expansion45861
+Node: Definitions46529
+Node: Define47314
+Node: Arguments49520
+Node: Pseudo Arguments51268
+Node: Undefine54483
+Node: Defn55613
+Node: Pushdef58346
+Node: Indir60680
+Node: Builtin62782
+Node: Conditionals64544
+Node: Ifdef65363
+Node: Ifelse66226
+Node: Shift69445
+Node: Forloop73244
+Node: Foreach75813
+Node: Debugging80792
+Node: Dumpdef81377
+Node: Trace82761
+Node: Debug Levels85449
+Node: Debug Output88255
+Node: Input Control89526
+Node: Dnl90063
+Node: Changequote91964
+Node: Changecom96760
+Node: Changeword100276
+Node: M4wrap105717
+Node: File Inclusion107978
+Node: Include108295
+Node: Search Path110895
+Node: Diversions111812
+Node: Divert113603
+Node: Undivert116129
+Node: Divnum119011
+Node: Cleardivert119475
+Node: Text handling120680
+Node: Len121403
+Node: Index macro121788
+Node: Regexp122559
+Node: Substr124808
+Node: Translit125859
+Node: Patsubst128581
+Node: Format132121
+Node: Arithmetic134188
+Node: Incr134637
+Node: Eval135412
+Node: Shell commands139821
+Node: Platform macros140743
+Node: Syscmd142487
+Node: Esyscmd144292
+Node: Sysval145340
+Node: Mkstemp146895
+Node: Miscellaneous150197
+Node: Errprint150630
+Node: Location151849
+Node: M4exit154651
+Node: Frozen files156738
+Node: Using frozen files157519
+Node: Frozen file format160759
+Node: Compatibility163822
+Node: Extensions164437
+Node: Incompatibilities168204
+Node: Other Incompatibilities176116
+Node: Answers178044
+Node: Improved exch178661
+Node: Improved forloop179199
+Node: Improved foreach181035
+Node: Improved cleardivert187974
+Node: Improved fatal_error188957
+Node: Copying This Manual190019
+Node: GNU Free Documentation License190275
+Node: Indices212669
+Node: Concept index212949
+Node: Macro index224692
+
+End Tag Table
diff --git a/src/bin/m4/doc/m4.texinfo b/src/bin/m4/doc/m4.texinfo
new file mode 100644
index 0000000000..b886565480
--- /dev/null
+++ b/src/bin/m4/doc/m4.texinfo
@@ -0,0 +1,6026 @@
+\input texinfo @c -*- texinfo -*-
+@comment ========================================================
+@comment %**start of header
+@setfilename m4.info
+@settitle GNU M4 macro processor
+@setchapternewpage odd
+@ifnothtml
+@setcontentsaftertitlepage
+@end ifnothtml
+@finalout
+
+@include version.texi
+
+@c @tabchar{}
+@c ----------
+@c The testsuite expects literal tab output in some examples, but
+@c literal tabs in texinfo lead to formatting issues.
+@macro tabchar
+@	@c
+@end macro
+
+@c @ovar{ARG}
+@c -------------------
+@c The ARG is an optional argument.  To be used for macro arguments in
+@c their documentation.
+@macro ovar{varname}
+@r{[}@var{\varname\}@r{]}
+@end macro
+
+@c @dvar{ARG, DEFAULT}
+@c -------------------
+@c The ARG is an optional argument, defaulting to DEFAULT.  To be used
+@c for macro arguments in their documentation.
+@macro dvar{varname, default}
+@r{[}@var{\varname\} = @samp{\default\}@r{]}
+@end macro
+
+@comment %**end of header
+@comment ========================================================
+
+@copying
+
+This manual is for @acronym{GNU} M4 (version @value{VERSION}, @value{UPDATED}),
+a package containing an implementation of the m4 macro language.
+
+Copyright @copyright{} 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005,
+2006 Free Software Foundation, Inc.
+
+@quotation
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the @acronym{GNU} Free Documentation License,
+Version 1.2 or any later version published by the Free Software
+Foundation; with no Invariant Sections, no Front-Cover Texts, and no
+Back-Cover Texts.  A copy of the license is included in the section
+entitled ``@acronym{GNU} Free Documentation License.''
+@end quotation
+@end copying
+
+@dircategory GNU programming tools
+@direntry
+* M4: (m4).                     A powerful macro processor.
+@end direntry
+
+@titlepage
+@title GNU M4, version @value{VERSION}
+@subtitle A powerful macro processor
+@subtitle Edition @value{EDITION}, @value{UPDATED}
+@author by Ren@'e Seindal
+
+@page
+@vskip 0pt plus 1filll
+@insertcopying
+@end titlepage
+
+@contents
+
+@ifnottex
+@node Top
+@top GNU M4
+@insertcopying
+@end ifnottex
+
+@acronym{GNU} @code{m4} is an implementation of the traditional UNIX macro
+processor.  It is mostly SVR4 compatible, although it has some
+extensions (for example, handling more than 9 positional parameters
+to macros).  @code{m4} also has builtin functions for including
+files, running shell commands, doing arithmetic, etc.  Autoconf needs
+@acronym{GNU} @code{m4} for generating @file{configure} scripts, but not for
+running them.
+
+@acronym{GNU} @code{m4} was originally written by Ren@'e Seindal, with
+subsequent changes by Fran@,{c}ois Pinard and other volunteers
+on the Internet.  All names and email addresses can be found in the
+files @file{m4-@value{VERSION}/@/AUTHORS} and
+@file{m4-@value{VERSION}/@/THANKS} from the @acronym{GNU} M4
+distribution.
+
+This is release @value{VERSION}.  It is now considered stable:  future
+releases in the 1.4.x series are only meant to fix bugs, increase speed,
+or improve documentation.  However@dots{}
+
+An experimental feature, which would improve @code{m4} usefulness,
+allows for changing the syntax for what is a @dfn{word} in @code{m4}.
+You should use:
+@comment ignore
+@example
+./configure --enable-changeword
+@end example
+@noindent
+if you want this feature compiled in.  The current implementation
+slows down @code{m4} considerably and is hardly acceptable.  In the
+future, @code{m4} 2.0 will come with a different set of new features
+that provide similar capabilities, but without the inefficiencies, so
+changeword will go away and @emph{you should not count on it}.
+
+@menu
+* Preliminaries::               Introduction and preliminaries
+* Invoking m4::                 Invoking @code{m4}
+* Syntax::                      Lexical and syntactic conventions
+
+* Macros::                      How to invoke macros
+* Definitions::                 How to define new macros
+* Conditionals::                Conditionals, loops, and recursion
+
+* Debugging::                   How to debug macros and input
+
+* Input Control::               Input control
+* File Inclusion::              File inclusion
+* Diversions::                  Diverting and undiverting output
+
+* Text handling::               Macros for text handling
+* Arithmetic::                  Macros for doing arithmetic
+* Shell commands::              Macros for running shell commands
+* Miscellaneous::               Miscellaneous builtin macros
+* Frozen files::                Fast loading of frozen state
+
+* Compatibility::               Compatibility with other versions of @code{m4}
+* Answers::                     Correct version of some examples
+* Copying This Manual::         How to make copies of this manual
+* Indices::                     Indices of concepts and macros
+
+@detailmenu
+ --- The Detailed Node Listing ---
+
+Introduction and preliminaries
+
+* Intro::                       Introduction to @code{m4}
+* History::                     Historical references
+* Bugs::                        Problems and bugs
+* Manual::                      Using this manual
+
+Invoking @code{m4}
+
+* Operation modes::             Command line options for operation modes
+* Preprocessor features::       Command line options for preprocessor features
+* Limits control::              Command line options for limits control
+* Frozen state::                Command line options for frozen state
+* Debugging options::           Command line options for debugging
+* Command line files::          Specifying input files on the command line
+
+Lexical and syntactic conventions
+
+* Names::                       Macro names
+* Quoted strings::              Quoting input to @code{m4}
+* Comments::                    Comments in @code{m4} input
+* Other tokens::                Other kinds of input tokens
+* Input processing::            How @code{m4} copies input to output
+
+How to invoke macros
+
+* Invocation::                  Macro invocation
+* Inhibiting Invocation::       Preventing macro invocation
+* Macro Arguments::             Macro arguments
+* Quoting Arguments::           On Quoting Arguments to macros
+* Macro expansion::             Expanding macros
+
+How to define new macros
+
+* Define::                      Defining a new macro
+* Arguments::                   Arguments to macros
+* Pseudo Arguments::            Special arguments to macros
+* Undefine::                    Deleting a macro
+* Defn::                        Renaming macros
+* Pushdef::                     Temporarily redefining macros
+
+* Indir::                       Indirect call of macros
+* Builtin::                     Indirect call of builtins
+
+Conditionals, loops, and recursion
+
+* Ifdef::                       Testing if a macro is defined
+* Ifelse::                      If-else construct, or multibranch
+* Shift::                       Recursion in @code{m4}
+* Forloop::                     Iteration by counting
+* Foreach::                     Iteration by list contents
+
+How to debug macros and input
+
+* Dumpdef::                     Displaying macro definitions
+* Trace::                       Tracing macro calls
+* Debug Levels::                Controlling debugging output
+* Debug Output::                Saving debugging output
+
+Input control
+
+* Dnl::                         Deleting whitespace in input
+* Changequote::                 Changing the quote characters
+* Changecom::                   Changing the comment delimiters
+* Changeword::                  Changing the lexical structure of words
+* M4wrap::                      Saving text until end of input
+
+File inclusion
+
+* Include::                     Including named files
+* Search Path::                 Searching for include files
+
+Diverting and undiverting output
+
+* Divert::                      Diverting output
+* Undivert::                    Undiverting output
+* Divnum::                      Diversion numbers
+* Cleardivert::                 Discarding diverted text
+
+Macros for text handling
+
+* Len::                         Calculating length of strings
+* Index macro::                 Searching for substrings
+* Regexp::                      Searching for regular expressions
+* Substr::                      Extracting substrings
+* Translit::                    Translating characters
+* Patsubst::                    Substituting text by regular expression
+* Format::                      Formatting strings (printf-like)
+
+Macros for doing arithmetic
+
+* Incr::                        Decrement and increment operators
+* Eval::                        Evaluating integer expressions
+
+Macros for running shell commands
+
+* Platform macros::             Determining the platform
+* Syscmd::                      Executing simple commands
+* Esyscmd::                     Reading the output of commands
+* Sysval::                      Exit status
+* Mkstemp::                     Making temporary files
+
+Miscellaneous builtin macros
+
+* Errprint::                    Printing error messages
+* Location::                    Printing current location
+* M4exit::                      Exiting from @code{m4}
+
+Fast loading of frozen state
+
+* Using frozen files::          Using frozen files
+* Frozen file format::          Frozen file format
+
+Compatibility with other versions of @code{m4}
+
+* Extensions::                  Extensions in @acronym{GNU} M4
+* Incompatibilities::           Facilities in System V m4 not in GNU M4
+* Other Incompatibilities::     Other incompatibilities
+
+Correct version of some examples
+
+* Improved exch::               Solution for @code{exch}
+* Improved forloop::            Solution for @code{forloop}
+* Improved foreach::            Solution for @code{foreach}
+* Improved cleardivert::        Solution for @code{cleardivert}
+* Improved fatal_error::        Solution for @code{fatal_error}
+
+How to make copies of this manual
+
+* GNU Free Documentation License::  License for copying this manual
+
+Indices of concepts and macros
+
+* Concept index::               Index for many concepts
+* Macro index::                 Index for all @code{m4} macros
+
+@end detailmenu
+@end menu
+
+@node Preliminaries
+@chapter Introduction and preliminaries
+
+This first chapter explains what @acronym{GNU} @code{m4} is, where @code{m4}
+comes from, how to read and use this documentation, how to call the
+@code{m4} program, and how to report bugs about it.  It concludes by
+giving tips for reading the remainder of the manual.
+
+The following chapters then detail all the features of the @code{m4}
+language.
+
+@menu
+* Intro::                       Introduction to @code{m4}
+* History::                     Historical references
+* Bugs::                        Problems and bugs
+* Manual::                      Using this manual
+@end menu
+
+@node Intro
+@section Introduction to @code{m4}
+
+@code{m4} is a macro processor, in the sense that it copies its
+input to the output, expanding macros as it goes.  Macros are either
+builtin or user-defined, and can take any number of arguments.
+Besides just doing macro expansion, @code{m4} has builtin functions
+for including named files, running shell commands, doing integer
+arithmetic, manipulating text in various ways, performing recursion,
+etc.@dots{}  @code{m4} can be used either as a front-end to a compiler,
+or as a macro processor in its own right.
+
+The @code{m4} macro processor is widely available on all UNIXes, and has
+been standardized by @acronym{POSIX}.
+Usually, only a small percentage of users are aware of its existence.
+However, those who find it often become committed users.  The
+popularity of @acronym{GNU} Autoconf, which requires @acronym{GNU}
+@code{m4} for @emph{generating} @file{configure} scripts, is an incentive
+for many to install it, while these people will not themselves
+program in @code{m4}.  @acronym{GNU} @code{m4} is mostly compatible with the
+System V, Release 3 version, except for some minor differences.
+@xref{Compatibility}, for more details.
+
+Some people find @code{m4} to be fairly addictive.  They first use
+@code{m4} for simple problems, then take bigger and bigger challenges,
+learning how to write complex sets of @code{m4} macros along the way.
+Once really addicted, users pursue writing of sophisticated @code{m4}
+applications even to solve simple problems, devoting more time
+debugging their @code{m4} scripts than doing real work.  Beware that
+@code{m4} may be dangerous for the health of compulsive programmers.
+
+@node History
+@section Historical references
+
+@code{GPM} was an important ancestor of @code{m4}.  See
+C. Stratchey: ``A General Purpose Macro generator'', Computer Journal
+8,3 (1965), pp. 225 ff.  @code{GPM} is also succinctly described into
+David Gries classic ``Compiler Construction for Digital Computers''.
+
+The classic B. Kernighan and P.J. Plauger: ``Software Tools'',
+Addison-Wesley, Inc. (1976) describes and implements a Unix
+macro-processor language, which inspired Dennis Ritchie to write
+@code{m3}, a macro processor for the AP-3 minicomputer.
+
+Kernighan and Ritchie then joined forces to develop the original
+@code{m4}, as described in ``The M4 Macro Processor'', Bell
+Laboratories (1977).  It had only 21 builtin macros.
+
+While @code{GPM} was more @emph{pure}, @code{m4} is meant to deal with
+the true intricacies of real life: macros can be recognized without
+being pre-announced, skipping whitespace or end-of-lines is easier,
+more constructs are builtin instead of derived, etc.
+
+Originally, the Kernighan and Plauger macro-processor, and then
+@code{m3}, formed the engine for the Rational FORTRAN preprocessor,
+that is, the @code{Ratfor} equivalent of @code{cpp}.  Later, @code{m4}
+was used as a frontend for @code{Ratfor}, @code{C} and @code{Cobol}.
+
+Ren@'e Seindal released his implementation of @code{m4}, @acronym{GNU}
+@code{m4},
+in 1990, with the aim of removing the artificial limitations in many
+of the traditional @code{m4} implementations, such as maximum line
+length, macro size, or number of macros.
+
+The late Professor A. Dain Samples described and implemented a further
+evolution in the form of @code{M5}: ``User's Guide to the M5 Macro
+Language: 2nd edition'', Electronic Announcement on comp.compilers
+newsgroup (1992).
+
+Fran@,{c}ois Pinard took over maintenance of @acronym{GNU} @code{m4} in
+1992, until 1994 when he released @acronym{GNU} @code{m4} 1.4, which was
+the stable release for 10 years.  It was at this time that @acronym{GNU}
+Autoconf decided to require @acronym{GNU} @code{m4} as its underlying
+engine, since all other implementations of @code{m4} had too many
+limitations.
+
+More recently, in 2004, Paul Eggert released 1.4.1 and 1.4.2 which
+addressed some long standing bugs in the venerable 1.4 release.
+Then in 2005 Gary V. Vaughan collected together the many
+patches to @acronym{GNU} @code{m4} 1.4 that were floating around the net and
+released 1.4.3 and 1.4.4.  And in 2006, Eric Blake joined the team and
+prepared patches for the release of 1.4.5, 1.4.6, 1.4.7, and 1.4.8.
+
+Meanwhile, development has continued on new features for @code{m4}, such
+as dynamic module loading and additional builtins.  When complete,
+@acronym{GNU} @code{m4} 2.0 will start a new series of releases.
+
+@node Bugs
+@section Problems and bugs
+
+If you have problems with @acronym{GNU} M4 or think you've found a bug,
+please report it.  Before reporting a bug, make sure you've actually
+found a real bug.  Carefully reread the documentation and see if it
+really says you can do what you're trying to do.  If it's not clear
+whether you should be able to do something or not, report that too; it's
+a bug in the documentation!
+
+Before reporting a bug or trying to fix it yourself, try to isolate it
+to the smallest possible input file that reproduces the problem.  Then
+send us the input file and the exact results @code{m4} gave you.  Also
+say what you expected to occur; this will help us decide whether the
+problem was really in the documentation.
+
+Once you've got a precise problem, send e-mail to (Internet)
+@email{bug-m4@@gnu.org}.  Please include the version number of @code{m4}
+you are using.  You can get this information with the command
+@kbd{m4 --version}.  Also provide details about the platform you are
+executing on.
+
+Non-bug suggestions are always welcome as well.  If you have questions
+about things that are unclear in the documentation or are just obscure
+features, please report them too.
+
+@node Manual
+@section Using this manual
+
+This manual contains a number of examples of @code{m4} input and output,
+and a simple notation is used to distinguish input, output and error
+messages from @code{m4}.  Examples are set out from the normal text, and
+shown in a fixed width font, like this
+
+@comment ignore
+@example
+This is an example of an example!
+@end example
+
+To distinguish input from output, all output from @code{m4} is prefixed
+by the string @samp{@result{}}, and all error messages by the string
+@samp{@error{}}.  Thus
+
+@comment ignore
+@example
+Example of input line
+@result{}Output line from m4
+@error{}and an error message
+@end example
+
+The sequence @samp{^D} in an example indicates the end of the input file.
+The majority of these examples are self-contained, and you can run them
+with similar results by invoking @kbd{m4 -d}.  In fact, the testsuite
+that is bundled in the @acronym{GNU} M4 package consists of the examples
+in this document!
+
+As each of the predefined macros in @code{m4} is described, a prototype
+call of the macro will be shown, giving descriptive names to the
+arguments, e.g.,
+
+@deffn Composite example (@var{string}, @dvar{count, 1}, @
+  @ovar{argument}@dots{})
+This is a sample prototype.  There is not really a macro named
+@code{example}, but this documents that if there were, it would be a
+Composite macro, rather than a Builtin.  It requires at least one
+argument, @var{string}.  Remember that in @code{m4}, there must not be a
+space between the macro name and the opening parenthesis, unless it was
+intended to call the macro without any arguments.  The brackets around
+@var{count} and @var{argument} show that these arguments are optional.
+If @var{count} is omitted, the macro behaves as if count were @samp{1},
+whereas if @var{argument} is omitted, the macro behaves as if it were
+the empty string.  A blank argument is not the same as an omitted
+argument.  For example, @samp{example(`a')}, @samp{example(`a',`1')},
+and @samp{example(`a',`1',)} would behave identically with @var{count}
+set to @samp{1}; while @samp{example(`a',)} and @samp{example(`a',`')}
+would explicitly pass the empty string for @var{count}.  The ellipses
+(@samp{@dots{}}) show that the macro processes additional arguments
+after @var{argument}, rather than ignoring them.
+@end deffn
+
+All macro arguments in @code{m4} are strings, but some are given
+special interpretation, e.g., as numbers, file names, regular
+expressions, etc.  The documentation for each macro will state how the
+parameters are interpreted, and what happens if the argument cannot be
+parsed according to the desired interpretation.  Unless specified
+otherwise, a parameter specified to be a number is parsed as a decimal,
+even if the argument has leading zeros; and parsing the empty string as
+a number results in 0 rather than an error, although a warning will be
+issued.
+
+This document consistently writes and uses @dfn{builtin}, without a
+hyphen, as if it were an English word.  This is how the @code{builtin}
+primitive is spelled within @code{m4}.
+
+@node Invoking m4
+@chapter Invoking @code{m4}
+
+The format of the @code{m4} command is:
+
+@comment ignore
+@example
+@code{m4} @r{[}@var{option}@dots{}@r{]} @r{[}@var{file}@dots{}@r{]}
+@end example
+
+@cindex command line, options
+@cindex options, command line
+@cindex @env{POSIXLY_CORRECT}
+All options begin with @samp{-}, or if long option names are used, with
+@samp{--}.  A long option name need not be written completely, any
+unambiguous prefix is sufficient.  @acronym{POSIX} requires @code{m4} to
+recognize arguments intermixed with files, even when
+@env{POSIXLY_CORRECT} is set in the environment.  Most options take
+effect at startup regardless of their position, but some are documented
+below as taking effect after any files that occurred earlier in the
+command line.  The argument @option{--} is a marker to denote the end of
+options.
+
+With short options, options that do not take arguments may be combined
+into a single command line argument with subsequent options, options
+with mandatory arguments may be provided either as a single command line
+argument or as two arguments, and options with optional arguments must
+be provided as a single argument.  In other words,
+@kbd{m4 -QPDfoo -d a -d+f} is equivalent to
+@kbd{m4 -Q -P -D foo -d -d+f -- ./a}, although the latter form is
+considered canonical.
+
+With long options, options with mandatory arguments may be provided with
+an equal sign (@samp{=}) in a single argument, or as two arguments, and
+options with optional arguments must be provided as a single argument.
+In other words, @kbd{m4 --def foo --debug a} is equivalent to
+@kbd{m4 --define=foo --debug= -- ./a}, although the latter form is
+considered canonical (not to mention more robust, in case a future
+version of @code{m4} introduces an option named @option{--default}).
+
+@code{m4} understands the following options, grouped by functionality.
+
+@menu
+* Operation modes::             Command line options for operation modes
+* Preprocessor features::       Command line options for preprocessor features
+* Limits control::              Command line options for limits control
+* Frozen state::                Command line options for frozen state
+* Debugging options::           Command line options for debugging
+* Command line files::          Specifying input files on the command line
+@end menu
+
+@node Operation modes
+@section Command line options for operation modes
+
+Several options control the overall operation of @code{m4}:
+
+@table @code
+@item --help
+Print a help summary on standard output, then immediately exit
+@code{m4} without reading any input files or performing any other
+actions.
+
+@item --version
+Print the version number of the program on standard output, then
+immediately exit @code{m4} without reading any input files or
+performing any other actions.
+
+@item -E
+@itemx --fatal-warnings
+Stop execution and exit @code{m4} once the first warning has been
+issued, considering all of them to be fatal.
+
+@item -i
+@itemx --interactive
+@itemx -e
+Makes this invocation of @code{m4} interactive.  This means that all
+output will be unbuffered, and interrupts will be ignored.  The
+spelling @option{-e} exists for compatibility with other @code{m4}
+implementations, and issues a warning because it may be withdrawn in a
+future version of @acronym{GNU} M4.
+
+@item -P
+@itemx --prefix-builtins
+Internally modify @emph{all} builtin macro names so they all start with
+the prefix @samp{m4_}.  For example, using this option, one should write
+@samp{m4_define} instead of @samp{define}, and @samp{m4___file__}
+instead of @samp{__file__}.  This option has no effect if @option{-R}
+is also specified.
+
+@item -Q
+@itemx --quiet
+@itemx --silent
+Suppress warnings, such as missing or superfluous arguments in macro
+calls, or treating the empty string as zero.
+
+@item -W @var{REGEXP}
+@itemx --word-regexp=@var{REGEXP}
+Use @var{REGEXP} as an alternative syntax for macro names.  This
+experimental option will not be present in all @acronym{GNU} @code{m4}
+implementations (@pxref{Changeword}).
+@end table
+
+@node Preprocessor features
+@section Command line options for preprocessor features
+
+@cindex macro definitions, on the command line
+@cindex command line, macro definitions on the
+Several options allow @code{m4} to behave more like a preprocessor.
+Macro definitions and deletions can be made on the command line, the
+search path can be altered, and the output file can track where the
+input came from.  These features occur with the following options:
+
+@table @code
+@item -D @var{NAME}@r{[}=@var{VALUE}@r{]}
+@itemx --define=@var{NAME}@r{[}=@var{VALUE}@r{]}
+This enters @var{NAME} into the symbol table, before any input files are
+read.  If @samp{=@var{VALUE}} is missing, the value is taken to be the
+empty string.  The @var{VALUE} can be any string, and the macro can be
+defined to take arguments, just as if it was defined from within the
+input.  This option may be given more than once; order with respect to
+file names is significant, and redefining the same @var{NAME} loses the
+previous value.
+
+@item -I @var{DIRECTORY}
+@itemx --include=@var{DIRECTORY}
+Make @code{m4} search @var{DIRECTORY} for included files that are not
+found in the current working directory.  @xref{Search Path}, for more
+details.  This option may be given more than once.
+
+@item -s
+@itemx --synclines
+Generate synchronization lines, for use by the C preprocessor or other
+similar tools.  Order is significant with respect to file names.  This
+option is useful, for example, when @code{m4} is used as a
+front end to a compiler.  Source file name and line number information
+is conveyed by directives of the form @samp{#line @var{linenum}
+"@var{file}"}, which are inserted as needed into the middle of the
+output.  Such directives mean that the following line originated or was
+expanded from the contents of input file @var{file} at line
+@var{linenum}.  The @samp{"@var{file}"} part is often omitted when
+the file name did not change from the previous directive.
+
+Synchronization directives are always given on complete lines by
+themselves.  When a synchronization discrepancy occurs in the middle of
+an output line, the associated synchronization directive is delayed
+until the beginning of the next generated line.
+
+@item -U @var{NAME}
+@itemx --undefine=@var{NAME}
+This deletes any predefined meaning @var{NAME} might have.  Obviously,
+only predefined macros can be deleted in this way.  This option may be
+given more than once; undefining a @var{NAME} that does not have a
+definition is silently ignored.  Order is significant with respect to
+file names.
+@end table
+
+@node Limits control
+@section Command line options for limits control
+
+There are some limits within @code{m4} that can be tuned.  For
+compatibility, @code{m4} also accepts some options that control limits
+in other implementations, but which are automatically unbounded (limited
+only by your hardware and operating system constraints) in @acronym{GNU}
+@code{m4}.
+
+@table @code
+@item -G
+@itemx --traditional
+Suppress all the extensions made in this implementation, compared to the
+System V version.  @xref{Compatibility}, for a list of these.
+
+@item -H @var{NUM}
+@itemx --hashsize=@var{NUM}
+Make the internal hash table for symbol lookup be @var{NUM} entries big.
+For better performance, the number should be prime, but this is not
+checked.  The default is 509 entries.  It should not be necessary to
+increase this value, unless you define an excessive number of macros.
+
+@item -L @var{NUM}
+@itemx --nesting-limit=@var{NUM}
+Artificially limit the nesting of macro calls to @var{NUM} levels,
+stopping program execution if this limit is ever exceeded.  When not
+specified, nesting is limited to 1024 levels.  A value of zero means
+unlimited; but then heavily nested code could potentially cause a stack
+overflow.
+
+The precise effect of this option might be more correctly associated
+with textual nesting than dynamic recursion.  It has been useful
+when some complex @code{m4} input was generated by mechanical means.
+Most users would never need this option.  If shown to be obtrusive,
+this option (which is still experimental) might well disappear.
+
+This option does @emph{not} have the ability to break endless
+rescanning loops, since these do not necessarily consume much memory
+or stack space.  Through clever usage of rescanning loops, one can
+request complex, time-consuming computations from @code{m4} with useful
+results.  Putting limitations in this area would break @code{m4} power.
+There are many pathological cases: @w{@samp{define(`a', `a')a}} is
+only the simplest example (but @pxref{Compatibility}).  Expecting @acronym{GNU}
+@code{m4} to detect these would be a little like expecting a compiler
+system to detect and diagnose endless loops: it is a quite @emph{hard}
+problem in general, if not undecidable!
+
+@item -B @var{NUM}
+@itemx -S @var{NUM}
+@itemx -T @var{NUM}
+These options are present for compatibility with System V @code{m4}, but
+do nothing in this implementation.  They may disappear in future
+releases, and issue a warning to that effect.
+
+@item -N @var{NUM}
+@itemx --diversions=@var{NUM}
+These options are present only for compatibility with previous
+versions of @acronym{GNU} @code{m4}, and were controlling the number of
+possible diversions which could be used at the same time.  They do nothing,
+because there is no fixed limit anymore.  They may disappear in future
+releases, and issue a warning to that effect.
+@end table
+
+@node Frozen state
+@section Command line options for frozen state
+
+@acronym{GNU} @code{m4} comes with a feature of freezing internal state
+(@pxref{Frozen files}).  This can be used to speed up @code{m4}
+execution when reusing a common initialization script.
+
+@table @code
+@item -F @var{FILE}
+@itemx --freeze-state=@var{FILE}
+Once execution is finished, write out the frozen state on the specified
+@var{FILE}.  It is conventional, but not required, for @var{FILE} to end
+in @samp{.m4f}.
+
+@item -R @var{FILE}
+@itemx --reload-state=@var{FILE}
+Before execution starts, recover the internal state from the specified
+frozen @var{FILE}.  The options @option{-D}, @option{-U}, and
+@option{-t} take effect after state is reloaded, but before the input
+files are read.
+@end table
+
+@node Debugging options
+@section Command line options for debugging
+
+Finally, there are several options for aiding in debugging @code{m4}
+scripts.
+
+@table @code
+@item -d@r{[}@var{FLAGS}@r{]}
+@itemx --debug@r{[}=@var{FLAGS}@r{]}
+Set the debug-level according to the flags @var{FLAGS}.  The debug-level
+controls the format and amount of information presented by the debugging
+functions.  @xref{Debug Levels}, for more details on the format and
+meaning of @var{FLAGS}.  If omitted, @var{FLAGS} defaults to @samp{aeq}.
+
+@item --debugfile=@var{FILE}
+@itemx -o @var{FILE}
+@itemx --error-output=@var{FILE}
+Redirect @code{dumpdef} output, debug messages, and trace output to the
+named @var{FILE}.  Warnings, error messages, and @code{errprint} output
+are still printed to standard error.  If unspecified, debug output goes
+to standard error; if empty, debug output is discarded.  @xref{Debug
+Output}, for more details.  The spellings @option{-o} and
+@option{--error-output} are misleading and inconsistent with other
+@acronym{GNU} tools; for now they are silently accepted as synonyms of
+@option{--debugfile}, but in a future version of M4, using them will
+cause a warning to be issued.
+
+@item -l @var{NUM}
+@itemx --arglength=@var{NUM}
+Restrict the size of the output generated by macro tracing to @var{NUM}
+characters per trace line.  If unspecified or zero, output is
+unlimited.  @xref{Debug Levels}, for more details.
+
+@item -t @var{NAME}
+@itemx --trace=@var{NAME}
+This enables tracing for the macro @var{NAME}, at any point where it is
+defined.  @var{NAME} need not be defined when this option is given.
+This option may be given more than once, and order is significant with
+respect to file names.  @xref{Trace}, for more details.
+@end table
+
+@node Command line files
+@section Specifying input files on the command line
+
+@cindex command line, file names on the
+@cindex file names, on the command line
+The remaining arguments on the command line are taken to be input file
+names.  If no names are present, standard input is read.  A file
+name of @file{-} is taken to mean standard input.  It is
+conventional, but not required, for input files to end in @samp{.m4}.
+
+The input files are read in the sequence given.  Standard input can be
+read more than once, so the file name @file{-} may appear multiple times
+on the command line; this makes a difference when input is from a
+terminal or other special file type.  It is an error if an input file
+ends in the middle of argument collection, a comment, or a quoted
+string.
+
+The options @option{--define} (@option{-D}), @option{--undefine}
+(@option{-U}), @option{--synclines} (@option{-s}), and @option{--trace}
+(@option{-t}) only take effect after processing input from any file
+names that occur earlier on the command line.
+
+If none of the input files invoked @code{m4exit} (@pxref{M4exit}), the
+exit status of @code{m4} will be 0 for success, 1 for general failure
+(such as problems with reading an input file), and 63 for version
+mismatch (@pxref{Using frozen files}).
+
+If you need to read a file whose name starts with a @file{-}, you can
+specify it as @samp{./-file}, or use @option{--} to mark the end of
+options.
+
+@node Syntax
+@chapter Lexical and syntactic conventions
+
+@cindex input tokens
+@cindex tokens
+As @code{m4} reads its input, it separates it into @dfn{tokens}.  A
+token is either a name, a quoted string, or any single character, that
+is not a part of either a name or a string.  Input to @code{m4} can also
+contain comments.  @acronym{GNU} @code{m4} does not yet understand
+locales; all operations are byte-oriented rather than
+character-oriented.  However, @code{m4} is eight-bit clean, so you can
+use non-@sc{ascii} characters in quoted strings (@pxref{Changequote}),
+comments (@pxref{Changecom}), and macro names (@pxref{Indir}), with the
+exception of the @sc{nul} character (the zero byte @samp{'\0'}).
+
+@menu
+* Names::                       Macro names
+* Quoted strings::              Quoting input to @code{m4}
+* Comments::                    Comments in @code{m4} input
+* Other tokens::                Other kinds of input tokens
+* Input processing::            How @code{m4} copies input to output
+@end menu
+
+@node Names
+@section Macro names
+
+@cindex names
+A name is any sequence of letters, digits, and the character @samp{_}
+(underscore), where the first character is not a digit.  @code{m4} will
+use the longest such sequence found in the input.  If a name has a
+macro definition, it will be subject to macro expansion
+(@pxref{Macros}).  Names are case-sensitive.
+
+Examples of legal names are: @samp{foo}, @samp{_tmp}, and @samp{name01}.
+
+@node Quoted strings
+@section Quoting input to @code{m4}
+
+@cindex quoted string
+A quoted string is a sequence of characters surrounded by quote
+strings, defaulting to
+@samp{`} and @samp{'}, where the nested begin and end quotes within the
+string are balanced.  The value of a string token is the text, with one
+level of quotes stripped off.  Thus
+
+@comment ignore
+@example
+`'
+@result{}
+@end example
+
+@noindent
+is the empty string, and double-quoting turns into single-quoting.
+
+@comment ignore
+@example
+``quoted''
+@result{}`quoted'
+@end example
+
+The quote characters can be changed at any time, using the builtin macro
+@code{changequote}.  @xref{Changequote}, for more information.
+
+@node Comments
+@section Comments in @code{m4} input
+
+@cindex comments
+Comments in @code{m4} are normally delimited by the characters @samp{#}
+and newline.  All characters between the comment delimiters are ignored,
+but the entire comment (including the delimiters) is passed through to
+the output---comments are @emph{not} discarded by @code{m4}.
+
+Comments cannot be nested, so the first newline after a @samp{#} ends
+the comment.  The commenting effect of the begin-comment string
+can be inhibited by quoting it.
+
+@example
+`quoted text' # `commented text'
+@result{}quoted text # `commented text'
+`quoting inhibits' `#' `comments'
+@result{}quoting inhibits # comments
+@end example
+
+The comment delimiters can be changed to any string at any time, using
+the builtin macro @code{changecom}.  @xref{Changecom}, for more
+information.
+
+@node Other tokens
+@section Other kinds of input tokens
+
+Any character, that is neither a part of a name, nor of a quoted string,
+nor a comment, is a token by itself.  When not in the context of macro
+expansion, all of these tokens are just copied to output.  However,
+during macro expansion, whitespace characters (space, tab, newline,
+formfeed, carriage return, vertical tab), parentheses (@samp{(} and
+@samp{)}), comma (@samp{,}), and dollar (@samp{$}) have additional
+roles, explained later.
+
+@node Input processing
+@section How @code{m4} copies input to output
+
+As @code{m4} reads the input token by token, it will copy each token
+directly to the output immediately.
+
+The exception is when it finds a word with a macro definition.  In that
+case @code{m4} will calculate the macro's expansion, possibly reading
+more input to get the arguments.  It then inserts the expansion in front
+of the remaining input.  In other words, the resulting text from a macro
+call will be read and parsed into tokens again.
+
+@code{m4} expands a macro as soon as possible.  If it finds a macro call
+when collecting the arguments to another, it will expand the second
+call first.  For a running example, examine how @code{m4} handles this
+input:
+
+@comment ignore
+@example
+format(`Result is %d', eval(`2**15'))
+@end example
+
+@noindent
+First, @code{m4} sees that the token @samp{format} is a macro name, so
+it collects the tokens @samp{(}, @samp{`Result is %d'}, @samp{,},
+and @samp{@w{ }}, before encountering another potential macro.  Sure
+enough, @samp{eval} is a macro name, so the nested argument collection
+picks up @samp{(}, @samp{`2**15'}, and @samp{)}, invoking the eval macro
+with the lone argument of @samp{2**15}.  The expansion of
+@samp{eval(2**15)} is @samp{32768}, which is then rescanned as the five
+tokens @samp{3}, @samp{2}, @samp{7}, @samp{6}, and @samp{8}; and
+combined with the next @samp{)}, the format macro now has all its
+arguments, as if the user had typed:
+
+@comment ignore
+@example
+format(`Result is %d', 32768)
+@end example
+
+@noindent
+The format macro expands to @samp{Result is 32768}, and we have another
+round of scanning for the tokens @samp{Result}, @samp{@w{ }},
+@samp{is}, @samp{@w{ }}, @samp{3}, @samp{2}, @samp{7}, @samp{6}, and
+@samp{8}.  None of these are macros, so the final output is
+
+@comment ignore
+@example
+@result{}Result is 32768
+@end example
+
+The order in which @code{m4} expands the macros can be explored using
+the trace facilities of @acronym{GNU} @code{m4} (@pxref{Trace}).
+
+This process continues until there are no more macro calls to expand and
+all the input has been consumed.
+
+@node Macros
+@chapter How to invoke macros
+
+This chapter covers macro invocation, macro arguments and how macro
+expansion is treated.
+
+@menu
+* Invocation::                  Macro invocation
+* Inhibiting Invocation::       Preventing macro invocation
+* Macro Arguments::             Macro arguments
+* Quoting Arguments::           On Quoting Arguments to macros
+* Macro expansion::             Expanding macros
+@end menu
+
+@node Invocation
+@section Macro invocation
+
+@cindex macro invocation
+Macro invocations has one of the forms
+
+@comment ignore
+@example
+name
+@end example
+
+@noindent
+which is a macro invocation without any arguments, or
+
+@comment ignore
+@example
+name(arg1, arg2, @dots{}, arg@var{n})
+@end example
+
+@noindent
+which is a macro invocation with @var{n} arguments.  Macros can have any
+number of arguments.  All arguments are strings, but different macros
+might interpret the arguments in different ways.
+
+The opening parenthesis @emph{must} follow the @var{name} directly, with
+no spaces in between.  If it does not, the macro is called with no
+arguments at all.
+
+For a macro call to have no arguments, the parentheses @emph{must} be
+left out.  The macro call
+
+@comment ignore
+@example
+name()
+@end example
+
+@noindent
+is a macro call with one argument, which is the empty string, not a call
+with no arguments.
+
+@node Inhibiting Invocation
+@section Preventing macro invocation
+
+An innovation of the @code{m4} language, compared to some of its
+predecessors (like Stratchey's @code{GPM}, for example), is the ability
+to recognize macro calls without resorting to any special, prefixed
+invocation character.  While generally useful, this feature might
+sometimes be the source of spurious, unwanted macro calls.  So, @acronym{GNU}
+@code{m4} offers several mechanisms or techniques for inhibiting the
+recognition of names as macro calls.
+
+First of all, many builtin macros cannot meaningfully be called
+without arguments.  For any of these macros, whenever an opening
+parenthesis does not immediately follow their name, the builtin macro
+call is not triggered.  This solves the most usual cases, like for
+@samp{include} or @samp{eval}.  Later in this document, the sentence
+``This macro is recognized only with parameters'' refers to this
+specific provision.
+
+There is also a command line option (@option{--prefix-builtins}, or
+@option{-P}, @pxref{Operation modes, , Invoking m4}) that renames all
+builtin macros with a prefix of @samp{m4_} at startup.  The option has
+no effect whatsoever on user defined macros.  For example, with this option,
+one has to write @code{m4_dnl} and even @code{m4_m4exit}.  It also has
+no effect on whether a macro requires parameters.
+
+Another alternative is to redefine problematic macros to a name less
+likely to cause conflicts, @xref{Definitions}.
+
+If your version of @acronym{GNU} @code{m4} has the @code{changeword} feature
+compiled in, it offers far more flexibility in specifying the
+syntax of macro names, both builtin or user-defined.  @xref{Changeword},
+for more information on this experimental feature.
+
+Of course, the simplest way to prevent a name from being interpreted
+as a call to an existing macro is to quote it.  The remainder of
+this section studies a little more deeply how quoting affects macro
+invocation, and how quoting can be used to inhibit macro invocation.
+
+Even if quoting is usually done over the whole macro name, it can also
+be done over only a few characters of this name (provided, of course,
+that the unquoted portions are not also a macro).  It is also possible
+to quote the empty string, but this works only @emph{inside} the name.
+For example:
+
+@example
+`divert'
+@result{}divert
+`d'ivert
+@result{}divert
+di`ver't
+@result{}divert
+div`'ert
+@result{}divert
+@end example
+
+@noindent
+all yield the string @samp{divert}.  While in both:
+
+@example
+`'divert
+@result{}
+divert`'
+@result{}
+@end example
+
+@noindent
+the @code{divert} builtin macro will be called, which expands to the
+empty string.
+
+The output of macro evaluations is always rescanned.  The following
+example would yield the string @samp{de}, exactly as if @code{m4}
+has been given @w{@samp{substr(`abcde', `3', `2')}} as input:
+
+@example
+define(`x', `substr(ab')
+@result{}
+define(`y', `cde, `3', `2')')
+@result{}
+x`'y
+@result{}de
+@end example
+
+Unquoted strings on either side of a quoted string are subject to
+being recognized as macro names.  In the following example, quoting the
+empty string allows for the second @code{macro} to be recognized as such:
+
+@example
+define(`macro', `m')
+@result{}
+macro(`m')macro
+@result{}mmacro
+macro(`m')`'macro
+@result{}mm
+@end example
+
+Quoting may prevent recognizing as a macro name the concatenation of a
+macro expansion with the surrounding characters.  In this example:
+
+@example
+define(`macro', `di$1')
+@result{}
+macro(`v')`ert'
+@result{}divert
+macro(`v')ert
+@result{}
+@end example
+
+@noindent
+the input will produce the string @samp{divert}.  When the quotes were
+removed, the @code{divert} builtin was called instead.
+
+@node Macro Arguments
+@section Macro arguments
+
+@cindex macros, arguments to
+@cindex arguments to macros
+When a name is seen, and it has a macro definition, it will be expanded
+as a macro.
+
+If the name is followed by an opening parenthesis, the arguments will be
+collected before the macro is called.  If too few arguments are
+supplied, the missing arguments are taken to be the empty string.
+However, some builtins are documented to behave differently for a
+missing optional argument than for an explicit empty string.  If there
+are too many arguments, the excess arguments are ignored.  Unquoted
+leading whitespace is stripped off all arguments, but whitespace
+generated by a macro expansion or occuring after a macro that expanded
+to an empty string remains intact.  Whitespace includes space, tab,
+newline, carriage return, vertical tab, and formfeed.
+
+@example
+define(`macro', `$1')
+@result{}
+macro( unquoted leading space lost)
+@result{}unquoted leading space lost
+macro(` quoted leading space kept')
+@result{} quoted leading space kept
+macro(
+ divert `unquoted space kept after expansion')
+@result{} unquoted space kept after expansion
+macro(macro(`
+')`whitespace from expansion kept')
+@result{}
+@result{}whitespace from expansion kept
+macro(`unquoted trailing whitespace kept'
+)
+@result{}unquoted trailing whitespace kept
+@result{}
+@end example
+
+Normally @code{m4} will issue warnings if a builtin macro is called
+with an inappropriate number of arguments, but it can be suppressed with
+the @option{--quiet} command line option (or @option{--silent}, or
+@option{-Q}, @pxref{Operation modes, , Invoking m4}).  For user
+defined macros, there is no check of the number of arguments given.
+
+Macros are expanded normally during argument collection, and whatever
+commas, quotes and parentheses that might show up in the resulting
+expanded text will serve to define the arguments as well.  Thus, if
+@var{foo} expands to @samp{, b, c}, the macro call
+
+@comment ignore
+@example
+bar(a foo, d)
+@end example
+
+@noindent
+is a macro call with four arguments, which are @samp{a }, @samp{b},
+@samp{c} and @samp{d}.  To understand why the first argument contains
+whitespace, remember that unquoted leading whitespace is never part
+of an argument, but trailing whitespace always is.
+
+It is possible for a macro's definition to change during argument
+collection, in which case the expansion uses the definition that was in
+effect at the time the opening @samp{(} was seen.
+
+@example
+define(`f', `1')
+@result{}
+f(define(`f', `2'))
+@result{}1
+f
+@result{}2
+@end example
+
+It is an error if the end of file occurs while collecting arguments.
+
+@example
+hello world
+@result{}hello world
+define(
+^D
+@error{}m4:stdin:2: ERROR: end of file in argument list
+@end example
+
+@node Quoting Arguments
+@section On Quoting Arguments to macros
+
+@cindex quoted macro arguments
+@cindex macros, quoted arguments to
+@cindex arguments, quoted macro
+Each argument has unquoted leading whitespace removed.  Within each
+argument, all unquoted parentheses must match.  For example, if
+@var{foo} is a macro,
+
+@comment ignore
+@example
+foo(() (`(') `(')
+@end example
+
+@noindent
+is a macro call, with one argument, whose value is @samp{() (() (}.
+Commas separate arguments, except when they occur inside quotes,
+comments, or unquoted parentheses.  @xref{Pseudo Arguments}, for
+examples.
+
+It is common practice to quote all arguments to macros, unless you are
+sure you want the arguments expanded.  Thus, in the above
+example with the parentheses, the `right' way to do it is like this:
+
+@comment ignore
+@example
+foo(`() (() (')
+@end example
+
+It is, however, in certain cases necessary or convenient to leave out
+quotes for some arguments, and there is nothing wrong in doing it.  It
+just makes life a bit harder, if you are not careful.  For consistency,
+this manual follows the rule of thumb that each layer of parentheses
+introduces another layer of single quoting, except when showing the
+consequences of quoting rules.  This is done even when the quoted string
+cannot be a macro, such as with integers when you have not changed the
+syntax via @code{changeword} (@pxref{Changeword}).
+
+@node Macro expansion
+@section Macro expansion
+
+@cindex macros, expansion of
+@cindex expansion of macros
+When the arguments, if any, to a macro call have been collected, the
+macro is expanded, and the expansion text is pushed back onto the input
+(unquoted), and reread.  The expansion text from one macro call might
+therefore result in more macros being called, if the calls are included,
+completely or partially, in the first macro calls' expansion.
+
+Taking a very simple example, if @var{foo} expands to @samp{bar}, and
+@var{bar} expands to @samp{Hello world}, the input
+
+@comment ignore
+@example
+foo
+@end example
+
+@noindent
+will expand first to @samp{bar}, and when this is reread and
+expanded, into @samp{Hello world}.
+
+@node Definitions
+@chapter How to define new macros
+
+@cindex macros, how to define new
+@cindex defining new macros
+Macros can be defined, redefined and deleted in several different ways.
+Also, it is possible to redefine a macro without losing a previous
+value, and bring back the original value at a later time.
+
+@menu
+* Define::                      Defining a new macro
+* Arguments::                   Arguments to macros
+* Pseudo Arguments::            Special arguments to macros
+* Undefine::                    Deleting a macro
+* Defn::                        Renaming macros
+* Pushdef::                     Temporarily redefining macros
+
+* Indir::                       Indirect call of macros
+* Builtin::                     Indirect call of builtins
+@end menu
+
+@node Define
+@section Defining a macro
+
+The normal way to define or redefine macros is to use the builtin
+@code{define}:
+
+@deffn Builtin define (@var{name}, @ovar{expansion})
+Defines @var{name} to expand to @var{expansion}.  If
+@var{expansion} is not given, it is taken to be empty.
+
+The expansion of @code{define} is void.
+The macro @code{define} is recognized only with parameters.
+@end deffn
+
+The following example defines the macro @var{foo} to expand to the text
+@samp{Hello World.}.
+
+@example
+define(`foo', `Hello world.')
+@result{}
+foo
+@result{}Hello world.
+@end example
+
+The empty line in the output is there because the newline is not
+a part of the macro definition, and it is consequently copied to
+the output.  This can be avoided by use of the macro @code{dnl}.
+@xref{Dnl}, for details.
+
+The first argument to @code{define} should be quoted; otherwise, if the
+macro is already defined, you will be defining a different macro.  This
+example shows the problems with underquoting, since we did not want to
+redefine @code{one}:
+
+@example
+define(foo, one)
+@result{}
+define(foo, two)
+@result{}
+one
+@result{}two
+@end example
+
+@cindex @acronym{GNU} extensions
+@acronym{GNU} @code{m4} normally replaces only the @emph{topmost}
+definition of a macro if it has several definitions from @code{pushdef}
+(@pxref{Pushdef}).  Some other implementations of @code{m4} replace all
+definitions of a macro with @code{define}.  @xref{Incompatibilities},
+for more details.
+
+As a @acronym{GNU} extension, the first argument to @code{define} does
+not have to be a simple word.
+It can be any text string, even the empty string.  A macro with a
+non-standard name cannot be invoked in the normal way, as the name is
+not recognized.  It can only be referenced by the builtins @code{Indir}
+(@pxref{Indir}) and @code{Defn} (@pxref{Defn}).
+
+@cindex arrays
+Arrays and associative arrays can be simulated by using this trick.
+
+@example
+define(`array', `defn(format(``array[%d]'', `$1'))')
+@result{}
+define(`array_set', `define(format(``array[%d]'', `$1'), `$2')')
+@result{}
+array_set(`4', `array element no. 4')
+@result{}
+array_set(`17', `array element no. 17')
+@result{}
+array(`4')
+@result{}array element no. 4
+array(eval(`10 + 7'))
+@result{}array element no. 17
+@end example
+
+Change the @code{%d} to @code{%s} and it is an associative array.
+
+@node Arguments
+@section Arguments to macros
+
+@cindex macros, arguments to
+@cindex Arguments to macros
+Macros can have arguments.  The @var{n}th argument is denoted by
+@code{$n} in the expansion text, and is replaced by the @var{n}th actual
+argument, when the macro is expanded.  Replacement of arguments happens
+before rescanning, regardless of how many nesting levels of quoting
+appear in the expansion.  Here is an example of a macro with
+two arguments.  It simply exchanges the order of the two arguments.
+
+@example
+define(`exch', `$2, $1')
+@result{}
+exch(`arg1', `arg2')
+@result{}arg2, arg1
+@end example
+
+This can be used, for example, if you like the arguments to
+@code{define} to be reversed.
+
+@example
+define(`exch', `$2, $1')
+@result{}
+define(exch(``expansion text'', ``macro''))
+@result{}
+macro
+@result{}expansion text
+@end example
+
+@xref{Quoting Arguments}, for an explanation of the double quotes.
+(You should try and improve this example so that clients of @code{exch}
+do not have to double quote; or @pxref{Improved exch, , Answers}).
+
+@cindex @acronym{GNU} extensions
+@acronym{GNU} @code{m4} allows the number following the @samp{$} to
+consist of one
+or more digits, allowing macros to have any number of arguments.  This
+is not so in UNIX implementations of @code{m4}, which only recognize
+one digit.
+
+As a special case, the zeroth argument, @code{$0}, is always the name
+of the macro being expanded.
+
+@example
+define(`test', ``Macro name: $0'')
+@result{}
+test
+@result{}Macro name: test
+@end example
+
+If you want quoted text to appear as part of the expansion text,
+remember that quotes can be nested in quoted strings.  Thus, in
+
+@example
+define(`foo', `This is macro `foo'.')
+@result{}
+foo
+@result{}This is macro foo.
+@end example
+
+@noindent
+The @samp{foo} in the expansion text is @emph{not} expanded, since it is
+a quoted string, and not a name.
+
+@node Pseudo Arguments
+@section Special arguments to macros
+
+@cindex special arguments to macros
+@cindex macros, special arguments to
+@cindex arguments to macros, special
+There is a special notation for the number of actual arguments supplied,
+and for all the actual arguments.
+
+The number of actual arguments in a macro call is denoted by @code{$#}
+in the expansion text.  Thus, a macro to display the number of arguments
+given can be
+
+@example
+define(`nargs', `$#')
+@result{}
+nargs
+@result{}0
+nargs()
+@result{}1
+nargs(`arg1', `arg2', `arg3')
+@result{}3
+nargs(`commas can be quoted, like this')
+@result{}1
+nargs(arg1#inside comments, commas do not separate arguments
+still arg1)
+@result{}1
+nargs((unquoted parentheses, like this, group arguments))
+@result{}1
+@end example
+
+The notation @code{$*} can be used in the expansion text to denote all
+the actual arguments, unquoted, with commas in between.  For example
+
+@example
+define(`echo', `$*')
+@result{}
+echo(arg1,    arg2, arg3 , arg4)
+@result{}arg1,arg2,arg3 ,arg4
+@end example
+
+Often each argument should be quoted, and the notation @code{$@@} handles
+that.  It is just like @code{$*}, except that it quotes each argument.
+A simple example of that is:
+
+@example
+define(`echo', `$@@')
+@result{}
+echo(arg1,    arg2, arg3 , arg4)
+@result{}arg1,arg2,arg3 ,arg4
+@end example
+
+Where did the quotes go?  Of course, they were eaten, when the expanded
+text were reread by @code{m4}.  To show the difference, try
+
+@example
+define(`echo1', `$*')
+@result{}
+define(`echo2', `$@@')
+@result{}
+define(`foo', `This is macro `foo'.')
+@result{}
+echo1(foo)
+@result{}This is macro This is macro foo..
+echo1(`foo')
+@result{}This is macro foo.
+echo2(foo)
+@result{}This is macro foo.
+echo2(`foo')
+@result{}foo
+@end example
+
+@noindent
+@xref{Trace}, if you do not understand this.  As another example of the
+difference, remember that comments encountered in arguments are passed
+untouched to the macro, and that quoting disables comments.
+
+@example
+define(`echo1', `$*')
+@result{}
+define(`echo2', `$@@')
+@result{}
+define(`foo', `bar')
+@result{}
+echo1(#foo'foo
+foo)
+@result{}#foo'foo
+@result{}bar
+echo2(#foo'foo
+foo)
+@result{}#foobar
+@result{}bar'
+@end example
+
+A @samp{$} sign in the expansion text, that is not followed by anything
+@code{m4} understands, is simply copied to the macro expansion, as any
+other text is.
+
+@example
+define(`foo', `$$$ hello $$$')
+@result{}
+foo
+@result{}$$$ hello $$$
+@end example
+
+If you want a macro to expand to something like @samp{$12}, the
+judicious use of nested quoting can put a safe character between the
+@code{$} and the next character, relying on the rescanning to remove the
+nested quote.  This will prevent @code{m4} from interpreting the
+@code{$} sign as a reference to an argument.
+
+@example
+define(`foo', `no nested quote: $1')
+@result{}
+foo(`arg')
+@result{}no nested quote: arg
+define(`foo', `nested quote around $: `$'1')
+@result{}
+foo(`arg')
+@result{}nested quote around $: $1
+define(`foo', `nested empty quote after $: $`'1')
+@result{}
+foo(`arg')
+@result{}nested empty quote after $: $1
+define(`foo', `nested quote around next character: $`1'')
+@result{}
+foo(`arg')
+@result{}nested quote around next character: $1
+define(`foo', `nested quote around both: `$1'')
+@result{}
+foo(`arg')
+@result{}nested quote around both: arg
+@end example
+
+@node Undefine
+@section Deleting a macro
+
+@cindex macros, how to delete
+@cindex deleting macros
+@cindex undefining macros
+A macro definition can be removed with @code{undefine}:
+
+@deffn Builtin undefine (@var{name}@dots{})
+For each argument, remove the macro @var{name}.  The macro names must
+necessarily be quoted, since they will be expanded otherwise.
+
+The expansion of @code{undefine} is void.
+The macro @code{undefine} is recognized only with parameters.
+@end deffn
+
+@example
+foo bar blah
+@result{}foo bar blah
+define(`foo', `some')define(`bar', `other')define(`blah', `text')
+@result{}
+foo bar blah
+@result{}some other text
+undefine(`foo')
+@result{}
+foo bar blah
+@result{}foo other text
+undefine(`bar', `blah')
+@result{}
+foo bar blah
+@result{}foo bar blah
+@end example
+
+Undefining a macro inside that macro's expansion is safe; the macro
+still expands to the definition that was in effect at the @samp{(}.
+
+@example
+define(`f', ``$0':$1')
+@result{}
+f(f(f(undefine(`f')`hello world')))
+@result{}f:f:f:hello world
+f(`bye')
+@result{}f(bye)
+@end example
+
+It is not an error for @var{name} to have no macro definition.  In that
+case, @code{undefine} does nothing.
+
+@node Defn
+@section Renaming macros
+
+@cindex macros, how to rename
+@cindex renaming macros
+It is possible to rename an already defined macro.  To do this, you need
+the builtin @code{defn}:
+
+@deffn Builtin defn (@var{name})
+Expands to the @emph{quoted definition} of @var{name}.  If the
+argument is not a defined macro, the expansion is void.
+
+If @var{name} is a user-defined macro, the quoted definition is simply
+the quoted expansion text.  If, instead, @var{name} is a builtin, the
+expansion is a special token, which points to the builtin's internal
+definition.  This token is only meaningful as the second argument to
+@code{define} (and @code{pushdef}), and is silently converted to an
+empty string in most other contexts.
+
+The macro @code{defn} is recognized only with parameters.
+@end deffn
+
+Its normal use is best understood through an example, which shows how to
+rename @code{undefine} to @code{zap}:
+
+@example
+define(`zap', defn(`undefine'))
+@result{}
+zap(`undefine')
+@result{}
+undefine(`zap')
+@result{}undefine(zap)
+@end example
+
+In this way, @code{defn} can be used to copy macro definitions, and also
+definitions of builtin macros.  Even if the original macro is removed,
+the other name can still be used to access the definition.
+
+The fact that macro definitions can be transferred also explains why you
+should use @code{$0}, rather than retyping a macro's name in its
+definition:
+
+@example
+define(`foo', `This is `$0'')
+@result{}
+define(`bar', defn(`foo'))
+@result{}
+bar
+@result{}This is bar
+@end example
+
+Macros used as string variables should be referred through @code{defn},
+to avoid unwanted expansion of the text:
+
+@example
+define(`string', `The macro dnl is very useful
+')
+@result{}
+string
+@result{}The macro@w{ }
+defn(`string')
+@result{}The macro dnl is very useful
+@result{}
+@end example
+
+However, it is important to remember that @code{m4} rescanning is purely
+textual.  If an unbalanced end-quote string occurs in a macro
+definition, the rescan will see that embedded quote as the termination
+of the quoted string, and the remainder of the macro's definition will
+be rescanned unquoted.  Thus it is a good idea to avoid unbalanced
+end-quotes in macro definitions or arguments to macros.
+
+@example
+define(`foo', a'a)
+@result{}
+define(`a', `A')
+@result{}
+define(`echo', `$@@')
+@result{}
+foo
+@result{}A'A
+defn(`foo')
+@result{}aA'
+echo(foo)
+@result{}AA'
+@end example
+
+Using @code{defn} to generate special tokens for builtin macros outside
+of expected contexts can sometimes trigger warnings.  But most of the
+time, such tokens are silently converted to the empty string.
+
+@example
+defn(`defn')
+@result{}
+define(defn(`divnum'), `cannot redefine a builtin token')
+@error{}m4:stdin:2: Warning: define: invalid macro name ignored
+@result{}
+divnum
+@result{}0
+@end example
+
+@node Pushdef
+@section Temporarily redefining macros
+
+@cindex macros, temporary redefinition of
+@cindex temporary redefinition of macros
+@cindex redefinition of macros, temporary
+It is possible to redefine a macro temporarily, reverting to the
+previous definition at a later time.  This is done with the builtins
+@code{pushdef} and @code{popdef}:
+
+@deffn Builtin pushdef (@var{name}, @ovar{expansion})
+@deffnx Builtin popdef (@var{name}@dots{})
+Analogous to @code{define} and @code{undefine}.
+
+These macros work in a stack-like fashion.  A macro is temporarily
+redefined with @code{pushdef}, which replaces an existing definition of
+@var{name}, while saving the previous definition, before the new one is
+installed.  If there is no previous definition, @code{pushdef} behaves
+exactly like @code{define}.
+
+If a macro has several definitions (of which only one is accessible),
+the topmost definition can be removed with @code{popdef}.  If there is
+no previous definition, @code{popdef} behaves like @code{undefine}.
+
+The expansion of both @code{pushdef} and @code{popdef} is void.
+The macros @code{pushdef} and @code{popdef} are recognized only with
+parameters.
+@end deffn
+
+@example
+define(`foo', `Expansion one.')
+@result{}
+foo
+@result{}Expansion one.
+pushdef(`foo', `Expansion two.')
+@result{}
+foo
+@result{}Expansion two.
+pushdef(`foo', `Expansion three.')
+@result{}
+pushdef(`foo', `Expansion four.')
+@result{}
+popdef(`foo')
+@result{}
+foo
+@result{}Expansion three.
+popdef(`foo', `foo')
+@result{}
+foo
+@result{}Expansion one.
+popdef(`foo')
+@result{}
+foo
+@result{}foo
+@end example
+
+If a macro with several definitions is redefined with @code{define}, the
+topmost definition is @emph{replaced} with the new definition.  If it is
+removed with @code{undefine}, @emph{all} the definitions are removed,
+and not only the topmost one.
+
+@example
+define(`foo', `Expansion one.')
+@result{}
+foo
+@result{}Expansion one.
+pushdef(`foo', `Expansion two.')
+@result{}
+foo
+@result{}Expansion two.
+define(`foo', `Second expansion two.')
+@result{}
+foo
+@result{}Second expansion two.
+undefine(`foo')
+@result{}
+foo
+@result{}foo
+@end example
+
+@cindex local variables
+@cindex variables, local
+Local variables within macros are made with @code{pushdef} and
+@code{popdef}.  At the start of the macro a new definition is pushed,
+within the macro it is manipulated and at the end it is popped,
+revealing the former definition.
+
+It is possible to temporarily redefine a builtin with @code{pushdef}
+and @code{defn}.
+
+@node Indir
+@section Indirect call of macros
+
+@cindex indirect call of macros
+@cindex call of macros, indirect
+@cindex macros, indirect call of
+@cindex @acronym{GNU} extensions
+Any macro can be called indirectly with @code{indir}:
+
+@deffn Builtin indir (@var{name}, @ovar{args@dots{}})
+Results in a call to the macro @var{name}, which is passed the
+rest of the arguments @var{args}.  If @var{name} is not defined, an
+error message is printed, and the expansion is void.
+
+The macro @code{indir} is recognized only with parameters.
+@end deffn
+
+This can be used to call macros with computed or ``invalid''
+names (@code{define} allows such names to be defined):
+
+@example
+define(`$$internal$macro', `Internal macro (name `$0')')
+@result{}
+$$internal$macro
+@result{}$$internal$macro
+indir(`$$internal$macro')
+@result{}Internal macro (name $$internal$macro)
+@end example
+
+The point is, here, that larger macro packages can have private macros
+defined, that will not be called by accident.  They can @emph{only} be
+called through the builtin @code{indir}.
+
+One other point to observe is that argument collection occurs before
+@code{indir} invokes @var{name}, so if argument collection changes the
+value of @var{name}, that will be reflected in the final expansion.
+This is different than the behavior when invoking macros directly,
+where the definition that was in effect before argument collection is
+used.
+
+@example
+define(`f', `1')
+@result{}
+f(define(`f', `2'))
+@result{}1
+indir(`f', define(`f', `3'))
+@result{}3
+indir(`f', undefine(`f'))
+@error{}m4:stdin:4: undefined macro `f'
+@result{}
+@end example
+
+When handed the result of @code{defn} (@pxref{Defn}) as one of its
+arguments, @code{indir} defers to the invoked @var{name} for whether a
+token representing a builtin is recognized or flattened to the empty
+string.
+
+@example
+indir(defn(`defn'), `divnum')
+@error{}m4:stdin:1: Warning: indir: invalid macro name ignored
+@result{}
+indir(`define', defn(`defn'), `divnum')
+@error{}m4:stdin:2: Warning: define: invalid macro name ignored
+@result{}
+indir(`define', `foo', defn(`divnum'))
+@result{}
+foo
+@result{}0
+indir(`divert', defn(`foo'))
+@error{}m4:stdin:5: empty string treated as 0 in builtin `divert'
+@result{}
+@end example
+
+@node Builtin
+@section Indirect call of builtins
+
+@cindex indirect call of builtins
+@cindex call of builtins, indirect
+@cindex builtins, indirect call of
+@cindex @acronym{GNU} extensions
+Builtin macros can be called indirectly with @code{builtin}:
+
+@deffn Builtin builtin (@var{name}, @ovar{args@dots{}})
+Results in a call to the builtin @var{name}, which is passed the
+rest of the arguments @var{args}.  If @var{name} does not name a
+builtin, an error message is printed, and the expansion is void.
+
+The macro @code{builtin} is recognized only with parameters.
+@end deffn
+
+This can be used even if @var{name} has been given another definition
+that has covered the original, or been undefined so that no macro
+maps to the builtin.
+
+@example
+pushdef(`define', `hidden')
+@result{}
+undefine(`undefine')
+@result{}
+define(`foo', `bar')
+@result{}hidden
+foo
+@result{}foo
+builtin(`define', `foo', defn(`divnum'))
+@result{}
+foo
+@result{}0
+builtin(`define', `foo', `BAR')
+@result{}
+foo
+@result{}BAR
+undefine(`foo')
+@result{}undefine(foo)
+foo
+@result{}BAR
+builtin(`undefine', `foo')
+@result{}
+foo
+@result{}foo
+@end example
+
+The @var{name} argument only matches the original name of the builtin,
+even when the @option{--prefix-builtins} option (or @option{-P},
+@pxref{Operation modes, , Invoking m4}) is in effect.  This is different
+from @code{indir}, which only tracks current macro names.
+
+Note that @code{indir} and @code{builtin} can be used to invoke builtins
+without arguments, even when they normally require parameters to be
+recognized; but it will provoke a warning, and result in a void expansion.
+
+@example
+builtin
+@result{}builtin
+builtin()
+@error{}m4:stdin:2: undefined builtin `'
+@result{}
+builtin(`builtin')
+@error{}m4:stdin:3: Warning: too few arguments to builtin `builtin'
+@result{}
+builtin(`builtin',)
+@error{}m4:stdin:4: undefined builtin `'
+@result{}
+@end example
+
+@node Conditionals
+@chapter Conditionals, loops, and recursion
+
+Macros, expanding to plain text, perhaps with arguments, are not quite
+enough.  We would like to have macros expand to different things, based
+on decisions taken at run-time.  For that, we need some kind of conditionals.
+Also, we would like to have some kind of loop construct, so we could do
+something a number of times, or while some condition is true.
+
+@menu
+* Ifdef::                       Testing if a macro is defined
+* Ifelse::                      If-else construct, or multibranch
+* Shift::                       Recursion in @code{m4}
+* Forloop::                     Iteration by counting
+* Foreach::                     Iteration by list contents
+@end menu
+
+@node Ifdef
+@section Testing if a macro is defined
+
+@cindex conditionals
+There are two different builtin conditionals in @code{m4}.  The first is
+@code{ifdef}:
+
+@deffn Builtin ifdef (@var{name}, @var{string-1}, @ovar{string-2})
+If @var{name} is defined as a macro, @code{ifdef} expands to
+@var{string-1}, otherwise to @var{string-2}.  If @var{string-2} is
+omitted, it is taken to be the empty string (according to the normal
+rules).
+
+The macro @code{ifdef} is recognized only with parameters.
+@end deffn
+
+@example
+ifdef(`foo', ``foo' is defined', ``foo' is not defined')
+@result{}foo is not defined
+define(`foo', `')
+@result{}
+ifdef(`foo', ``foo' is defined', ``foo' is not defined')
+@result{}foo is defined
+ifdef(`no_such_macro', `yes', `no', `extra argument')
+@error{}m4:stdin:4: Warning: excess arguments to builtin `ifdef' ignored
+@result{}no
+@end example
+
+@node Ifelse
+@section If-else construct, or multibranch
+
+@cindex comparing strings
+The other conditional, @code{ifelse}, is much more powerful.  It can be
+used as a way to introduce a long comment, as an if-else construct, or
+as a multibranch, depending on the number of arguments supplied:
+
+@deffn Builtin ifelse (@var{comment})
+@deffnx Builtin ifelse (@var{string-1}, @var{string-2}, @var{equal}, @
+  @ovar{not-equal})
+@deffnx Builtin ifelse (@var{string-1}, @var{string-2}, @var{equal-1}, @
+  @var{string-3}, @var{string-4}, @var{equal-2}, @dots{})
+Used with only one argument, the @code{ifelse} simply discards it and
+produces no output.
+
+If called with three or four arguments, @code{ifelse} expands into
+@var{equal}, if @var{string-1} and @var{string-2} are equal (character
+for character), otherwise it expands to @var{not-equal}.  A final fifth
+argument is ignored, after triggering a warning.
+
+If called with six or more arguments, and @var{string-1} and
+@var{string-2} are equal, @code{ifelse} expands into @var{equal-1},
+otherwise the first three arguments are discarded and the processing
+starts again.
+
+The macro @code{ifelse} is recognized only with parameters.
+@end deffn
+
+Using only one argument is a common @code{m4} idiom for introducing a
+block comment, as an alternative to repeatedly using @code{dnl}.  This
+special usage is recognized by @acronym{GNU} @code{m4}, so that in this
+case, the warning about missing arguments is never triggered.
+
+@example
+ifelse(`some comments')
+@result{}
+ifelse(`foo', `bar')
+@error{}m4:stdin:2: Warning: too few arguments to builtin `ifelse'
+@result{}
+@end example
+
+Using three or four arguments provides decision points.
+
+@example
+ifelse(`foo', `bar', `true')
+@result{}
+ifelse(`foo', `foo', `true')
+@result{}true
+define(`foo', `bar')
+@result{}
+ifelse(foo, `bar', `true', `false')
+@result{}true
+ifelse(foo, `foo', `true', `false')
+@result{}false
+@end example
+
+Notice how the first argument was used unquoted; it is common to compare
+the expansion of a macro with a string.  With this macro, you can now
+reproduce the behavior of many of the builtins, where the macro is
+recognized only with arguments.
+
+@example
+define(`foo', `ifelse(`$#', `0', ``$0'', `arguments:$#')')
+@result{}
+foo
+@result{}foo
+foo()
+@result{}arguments:1
+foo(`a', `b', `c')
+@result{}arguments:3
+@end example
+
+@cindex multibranches
+However, @code{ifelse} can take more than four arguments.  If given more
+than four arguments, @code{ifelse} works like a @code{case} or @code{switch}
+statement in traditional programming languages.  If @var{string-1} and
+@var{string-2} are equal, @code{ifelse} expands into @var{equal-1}, otherwise
+the procedure is repeated with the first three arguments discarded.  This
+calls for an example:
+
+@example
+ifelse(`foo', `bar', `third', `gnu', `gnats')
+@error{}m4:stdin:1: Warning: excess arguments to builtin `ifelse' ignored
+@result{}gnu
+ifelse(`foo', `bar', `third', `gnu', `gnats', `sixth')
+@result{}
+ifelse(`foo', `bar', `third', `gnu', `gnats', `sixth', `seventh')
+@result{}seventh
+ifelse(`foo', `bar', `3', `gnu', `gnats', `6', `7', `8')
+@error{}m4:stdin:4: Warning: excess arguments to builtin `ifelse' ignored
+@result{}7
+@end example
+
+Naturally, the normal case will be slightly more advanced than these
+examples.  A common use of @code{ifelse} is in macros implementing loops
+of various kinds.
+
+@node Shift
+@section Recursion in @code{m4}
+
+@cindex recursive macros
+@cindex macros, recursive
+There is no direct support for loops in @code{m4}, but macros can be
+recursive.  There is no limit on the number of recursion levels, other
+than those enforced by your hardware and operating system.
+
+@cindex loops
+Loops can be programmed using recursion and the conditionals described
+previously.
+
+There is a builtin macro, @code{shift}, which can, among other things,
+be used for iterating through the actual arguments to a macro:
+
+@deffn Builtin shift (@var{arg1}, @dots{})
+Takes any number of arguments, and expands to all its arguments except
+@var{arg1}, separated by commas, with each argument quoted.
+
+The macro @code{shift} is recognized only with parameters.
+@end deffn
+
+@example
+shift
+@result{}shift
+shift(`bar')
+@result{}
+shift(`foo', `bar', `baz')
+@result{}bar,baz
+@end example
+
+An example of the use of @code{shift} is this macro:
+
+@deffn Composite reverse (@dots{})
+Takes any number of arguments, and reverses their order.
+@end deffn
+
+It is implemented as:
+
+@example
+define(`reverse', `ifelse(`$#', `0', , `$#', `1', ``$1'',
+                          `reverse(shift($@@)), `$1'')')
+@result{}
+reverse
+@result{}
+reverse(`foo')
+@result{}foo
+reverse(`foo', `bar', `gnats', `and gnus')
+@result{}and gnus, gnats, bar, foo
+@end example
+
+While not a very interesting macro, it does show how simple loops can be
+made with @code{shift}, @code{ifelse} and recursion.  It also shows
+that @code{shift} is usually used with @samp{$@@}.  Sometimes, a
+recursive algorithm requires adding quotes to each element:
+
+@deffn Composite quote (@dots{})
+@deffnx Composite dquote (@dots{})
+@deffnx Composite dquote_elt (@dots{})
+Takes any number of arguments, and adds quoting.  With @code{quote},
+only one level of quoting is added, effectively removing whitespace
+after commas and turning multiple arguments into a single string.  With
+@code{dquote}, two levels of quoting are added, one around each element,
+and one around the list.  And with @code{dquote_elt}, two levels of
+quoting are added around each element.
+@end deffn
+
+An actual implementation of these three macros is distributed as
+@file{m4-@value{VERSION}/@/examples/@/quote.m4} in this package.  First,
+let's examine their usage:
+
+@example
+include(`quote.m4')
+@result{}
+-quote-dquote-dquote_elt-
+@result{}----
+-quote()-dquote()-dquote_elt()-
+@result{}--`'-`'-
+-quote(`1')-dquote(`1')-dquote_elt(`1')-
+@result{}-1-`1'-`1'-
+-quote(`1', `2')-dquote(`1', `2')-dquote_elt(`1', `2')-
+@result{}-1,2-`1',`2'-`1',`2'-
+define(`n', `$#')dnl
+-n(quote(`1', `2'))-n(dquote(`1', `2'))-n(dquote_elt(`1', `2'))-
+@result{}-1-1-2-
+dquote(dquote_elt(`1', `2'))
+@result{}``1'',``2''
+dquote_elt(dquote(`1', `2'))
+@result{}``1',`2''
+@end example
+
+The last two lines show that when given two arguments, @code{dquote}
+results in one string, while @code{dquote_elt} results in two.  Now,
+examine the implementation.  Note that @code{quote} and
+@code{dquote_elt} make decisions based on their number of arguments, so
+that when called without arguments, they result in nothing instead of a
+quoted empty string; this is so that it is possible to distinquish
+between no arguments and an empty first argument.  @code{dquote}, on the
+other hand, results in a string no matter what, since it is still
+possible to tell whether it was invoked without arguments based on the
+resulting string.
+
+@example
+undivert(`quote.m4')dnl
+@result{}divert(`-1')
+@result{}# quote(args) - convert args to single-quoted string
+@result{}define(`quote', `ifelse(`$#', `0', `', ``$*'')')
+@result{}# dquote(args) - convert args to quoted list of quoted strings
+@result{}define(`dquote', ``$@@'')
+@result{}# dquote_elt(args) - convert args to list of double-quoted strings
+@result{}define(`dquote_elt', `ifelse(`$#', `0', `', `$#', `1', ```$1''',
+@result{}                             ```$1'',$0(shift($@@))')')
+@result{}divert`'dnl
+@end example
+
+@node Forloop
+@section Iteration by counting
+
+@cindex for loops
+@cindex loops, counting
+@cindex counting loops
+Here is an example of a loop macro that implements a simple for loop.
+
+@deffn Composite forloop (@var{iterator}, @var{start}, @var{end}, @var{text})
+Takes the name in @var{iterator}, which must be a valid macro name, and
+successively assign it each integer value from @var{start} to @var{end},
+inclusive.  For each assignment to @var{iterator}, append @var{text} to
+the expansion of the @code{forloop}.  @var{text} may refer to
+@var{iterator}.  Any definition of @var{iterator} prior to this
+invocation is restored.
+@end deffn
+
+It can, for example, be used for simple counting:
+
+@example
+include(`forloop.m4')
+@result{}
+forloop(`i', `1', `8', `i ')
+@result{}1 2 3 4 5 6 7 8@w{ }
+@end example
+
+For-loops can be nested, like:
+
+@example
+include(`forloop.m4')
+@result{}
+forloop(`i', `1', `4', `forloop(`j', `1', `8', ` (i, j)')
+')
+@result{} (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6) (1, 7) (1, 8)
+@result{} (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6) (2, 7) (2, 8)
+@result{} (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6) (3, 7) (3, 8)
+@result{} (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6) (4, 7) (4, 8)
+@result{}
+@end example
+
+The implementation of the @code{forloop} macro is fairly
+straightforward.  The @code{forloop} macro itself is simply a wrapper,
+which saves the previous definition of the first argument, calls the
+internal macro @code{@w{_forloop}}, and re-establishes the saved
+definition of the first argument.
+
+The macro @code{@w{_forloop}} expands the fourth argument once, and
+tests to see if the iterator has reached the final value.  If it has
+not finished, it increments the iterator (using the predefined macro
+@code{incr}, @pxref{Incr}), and recurses.
+
+Here is an actual implementation of @code{forloop}, distributed as
+@file{m4-@value{VERSION}/@/examples/@/forloop.m4} in this package:
+
+@example
+undivert(`forloop.m4')dnl
+@result{}divert(`-1')
+@result{}# forloop(var, from, to, stmt) - simple version
+@result{}define(`forloop', `pushdef(`$1', `$2')_forloop($@@)popdef(`$1')')
+@result{}define(`_forloop',
+@result{}       `$4`'ifelse($1, `$3', `', `define(`$1', incr($1))$0($@@)')')
+@result{}divert`'dnl
+@end example
+
+Notice the careful use of quotes.  Certain macro arguments are left
+unquoted, each for its own reason.  Try to find out @emph{why} these
+arguments are left unquoted, and see what happens if they are quoted.
+(As presented, these two macros are useful but not very robust for
+general use.  They lack even basic error handling for cases like
+@var{start} less than @var{end}, @var{end} not numeric, or
+@var{iterator} not being a macro name.  See if you can improve these
+macros; or @pxref{Improved forloop, , Answers}).
+
+@node Foreach
+@section Iteration by list contents
+
+@cindex for each loops
+@cindex loops, list iteration
+@cindex iterating over lists
+Here is an example of a loop macro that implements list iteration.
+
+@deffn Composite foreach (@var{iterator}, @var{paren-list}, @var{text})
+@deffnx Composite foreachq (@var{iterator}, @var{quote-list}, @var{text})
+Takes the name in @var{iterator}, which must be a valid macro name, and
+successively assign it each value from @var{paren-list} or
+@var{quote-list}.  In @code{foreach}, @var{paren-list} is a
+comma-separated list of elements contained in parentheses.  In
+@code{foreachq}, @var{quote-list} is a comma-separated list of elements
+contained in a quoted string.  For each assignment to @var{iterator},
+append @var{text} to the overall expansion.  @var{text} may refer to
+@var{iterator}.  Any definition of @var{iterator} prior to this
+invocation is restored.
+@end deffn
+
+As an example, this displays each word in a list inside of a sentence,
+using an implementation of @code{foreach} distributed as
+@file{m4-@value{VERSION}/@/examples/@/foreach.m4}, and @code{foreachq}
+in @file{m4-@value{VERSION}/@/examples/@/foreachq.m4}.
+
+@example
+include(`foreach.m4')
+@result{}
+foreach(`x', (foo, bar, foobar), `Word was: x
+')dnl
+@result{}Word was: foo
+@result{}Word was: bar
+@result{}Word was: foobar
+include(`foreachq.m4')
+@result{}
+foreachq(`x', `foo, bar, foobar', `Word was: x
+')dnl
+@result{}Word was: foo
+@result{}Word was: bar
+@result{}Word was: foobar
+@end example
+
+It is possible to be more complex; each element of the @var{paren-list}
+or @var{quote-list} can itself be a list, to pass as further arguments
+to a helper macro.  This example generates a shell case statement:
+
+@example
+include(`foreach.m4')
+@result{}
+define(`_case', `  $1)
+    $2=" $1";;
+')dnl
+define(`_cat', `$1$2')dnl
+case $`'1 in
+@result{}case $1 in
+foreach(`x', `(`(`a', `vara')', `(`b', `varb')', `(`c', `varc')')',
+        `_cat(`_case', x)')dnl
+@result{}  a)
+@result{}    vara=" a";;
+@result{}  b)
+@result{}    varb=" b";;
+@result{}  c)
+@result{}    varc=" c";;
+esac
+@result{}esac
+@end example
+
+The implementation of the @code{foreach} macro is a bit more involved;
+it is a wrapper around two helper macros.  First, @code{@w{_arg1}} is
+needed to grab the first element of a list.  Second,
+@code{@w{_foreach}} implements the recursion, successively walking
+through the original list.  Here is a simple implementation of
+@code{foreach}:
+
+@example
+undivert(`foreach.m4')dnl
+@result{}divert(`-1')
+@result{}# foreach(x, (item_1, item_2, ..., item_n), stmt)
+@result{}#   parenthesized list, simple version
+@result{}define(`foreach', `pushdef(`$1')_foreach($@@)popdef(`$1')')
+@result{}define(`_arg1', `$1')
+@result{}define(`_foreach', `ifelse(`$2', `()', `',
+@result{}  `define(`$1', _arg1$2)$3`'$0(`$1', (shift$2), `$3')')')
+@result{}divert`'dnl
+@end example
+
+Unfortunately, that implementation is not robust to macro names as list
+elements.  Each iteration of @code{@w{_foreach}} is stripping another
+layer of quotes, leading to erratic results if list elements are not
+already fully expanded.  The first cut at implementing @code{foreachq}
+takes this into account.  Also, when using quoted elements in a
+@var{paren-list}, the overall list must be quoted.  A @var{quote-list}
+has the nice property of requiring fewer characters to create a list
+containing the same quoted elements.  To see the difference between the
+two macros, we attempt to pass double-quoted macro names in a list,
+expecting the macro name on output after one layer of quotes is removed
+during list iteration and the final layer removed during the final
+rescan:
+
+@example
+define(`a', `1')define(`b', `2')define(`c', `3')
+@result{}
+include(`foreach.m4')
+@result{}
+include(`foreachq.m4')
+@result{}
+foreach(`x', `(``a'', ``(b'', ``c)'')', `x
+')
+@result{}1
+@result{}(2)1
+@result{}
+@result{}, x
+@result{})
+foreachq(`x', ```a'', ``(b'', ``c)''', `x
+')dnl
+@result{}a
+@result{}(b
+@result{}c)
+@end example
+
+Obviously, @code{foreachq} did a better job; here is its implementation:
+
+@example
+undivert(`foreachq.m4')dnl
+@result{}include(`quote.m4')dnl
+@result{}divert(`-1')
+@result{}# foreachq(x, `item_1, item_2, ..., item_n', stmt)
+@result{}#   quoted list, simple version
+@result{}define(`foreachq', `pushdef(`$1')_foreachq($@@)popdef(`$1')')
+@result{}define(`_arg1', `$1')
+@result{}define(`_foreachq', `ifelse(quote($2), `', `',
+@result{}  `define(`$1', `_arg1($2)')$3`'$0(`$1', `shift($2)', `$3')')')
+@result{}divert`'dnl
+@end example
+
+Notice that @code{@w{_foreachq}} had to use the helper macro
+@code{quote} defined earlier (@pxref{Shift}), to ensure that the
+embedded @code{ifelse} call does not go haywire if a list element
+contains a comma.  Unfortunately, this implementation of @code{foreachq}
+has its own severe flaw.  Whereas the @code{foreach} implementation was
+linear, this macro is quadratic in the number of list elements, and is
+much more likely to trip up the limit set by the command line option
+@option{--nesting-limit} (or @option{-L}, @pxref{Limits control, ,
+Invoking m4}).  (It is possible to have robust iteration with linear
+behavior for either list style.  See if you can learn from the best
+elements of both of these implementations to create robust macros; or
+@pxref{Improved foreach, , Answers}).
+
+@node Debugging
+@chapter How to debug macros and input
+
+When writing macros for @code{m4}, they often do not work as intended on
+the first try (as is the case with most programming languages).
+Fortunately, there is support for macro debugging in @code{m4}.
+
+@menu
+* Dumpdef::                     Displaying macro definitions
+* Trace::                       Tracing macro calls
+* Debug Levels::                Controlling debugging output
+* Debug Output::                Saving debugging output
+@end menu
+
+@node Dumpdef
+@section Displaying macro definitions
+
+@cindex displaying macro definitions
+@cindex macros, displaying definitions
+@cindex definitions, displaying macro
+If you want to see what a name expands into, you can use the builtin
+@code{dumpdef}:
+
+@deffn Builtin dumpdef (@ovar{names@dots{}})
+Accepts any number of arguments.  If called without any arguments,
+it displays the definitions of all known names, otherwise it displays
+the definitions of the @var{names} given.  The output is printed to the
+current debug file (usually standard error), and is sorted by name.  If
+an unknown name is encountered, a warning is printed.
+
+The expansion of @code{dumpdef} is void.
+@end deffn
+
+@example
+define(`foo', `Hello world.')
+@result{}
+dumpdef(`foo')
+@error{}foo:@tabchar{}`Hello world.'
+@result{}
+dumpdef(`define')
+@error{}define:@tabchar{}<define>
+@result{}
+@end example
+
+The last example shows how builtin macros definitions are displayed.
+The definition that is dumped corresponds to what would occur if the
+macro were to be called at that point, even if other definitions are
+still live due to redefining a macro during argument collection.
+
+@example
+pushdef(`f', ``$0'1')pushdef(`f', ``$0'2')
+@result{}
+f(popdef(`f')dumpdef(`f'))
+@error{}f:@tabchar{}``$0'1'
+@result{}f2
+f(popdef(`f')dumpdef(`f'))
+@error{}m4:stdin:3: undefined macro `f'
+@result{}f1
+@end example
+
+@xref{Debug Levels}, for information on controlling the details of the
+display.
+
+@node Trace
+@section Tracing macro calls
+
+@cindex tracing macro expansion
+@cindex macro expansion, tracing
+@cindex expansion, tracing macro
+It is possible to trace macro calls and expansions through the builtins
+@code{traceon} and @code{traceoff}:
+
+@deffn Builtin traceon (@ovar{names@dots{}})
+@deffnx Builtin traceoff (@ovar{names@dots{}})
+When called without any arguments, @code{traceon} and @code{traceoff}
+will turn tracing on and off, respectively, for all defined macros.
+
+When called with arguments, only the macros listed in @var{names} are
+affected, whether or not they are currently defined.
+
+The expansion of @code{traceon} and @code{traceoff} is void.
+@end deffn
+
+Whenever a traced macro is called and the arguments have been collected,
+the call is displayed.  If the expansion of the macro call is not void,
+the expansion can be displayed after the call.  The output is printed
+to the current debug file (defaulting to standard error, @pxref{Debug
+Output}).
+
+@example
+define(`foo', `Hello World.')
+@result{}
+define(`echo', `$@@')
+@result{}
+traceon(`foo', `echo')
+@result{}
+foo
+@error{}m4trace: -1- foo -> `Hello World.'
+@result{}Hello World.
+echo(`gnus', `and gnats')
+@error{}m4trace: -1- echo(`gnus', `and gnats') -> ``gnus',`and gnats''
+@result{}gnus,and gnats
+@end example
+
+The number between dashes is the depth of the expansion.  It is one most
+of the time, signifying an expansion at the outermost level, but it
+increases when macro arguments contain unquoted macro calls.  The
+maximum number that will appear between dashes is controlled by the
+option @option{--nesting-limit} (@pxref{Limits control, , Invoking m4}).
+
+Tracing by name is an attribute that is preserved whether the macro is
+defined or not.  This allows the @option{-t} option to select macros to
+trace before those macros are defined.
+
+@example
+traceoff(`foo')
+@result{}
+traceon(`foo')
+@result{}
+foo
+@result{}foo
+define(`foo', `bar')
+@result{}
+foo
+@error{}m4trace: -1- foo -> `bar'
+@result{}bar
+undefine(`foo')
+@result{}
+ifdef(`foo', `yes', `no')
+@result{}no
+indir(`foo')
+@error{}m4:stdin:8: undefined macro `foo'
+@result{}
+define(`foo', `blah')
+@result{}
+foo
+@error{}m4trace: -1- foo -> `blah'
+@result{}blah
+traceoff
+@result{}
+foo
+@result{}blah
+@end example
+
+Tracing even works on builtins.  However, @command{defn} (@pxref{Defn})
+does not transfer tracing status.
+
+@example
+traceon(`eval', `m4_divnum')
+@result{}
+define(`m4_eval', defn(`eval'))
+@result{}
+define(`m4_divnum', defn(`divnum'))
+@result{}
+eval(divnum)
+@error{}m4trace: -1- eval(`0') -> `0'
+@result{}0
+m4_eval(m4_divnum)
+@error{}m4trace: -2- m4_divnum -> `0'
+@result{}0
+@end example
+
+@xref{Debug Levels}, for information on controlling the details of the
+display.
+
+@node Debug Levels
+@section Controlling debugging output
+
+@cindex controlling debugging output
+@cindex debugging output, controlling
+The @option{-d} option to @code{m4} (@pxref{Debugging options, ,
+Invoking m4}) controls the amount of details presented, when using the
+macros described in the preceding sections.
+
+The @var{flags} following the option can be one or more of the
+following:
+
+@table @code
+@item a
+Show the actual arguments in each macro call.  This applies to all macro
+calls if the @samp{t} flag is used, otherwise only the macros covered by
+calls of @code{traceon}.
+
+@item c
+Show several trace lines for each macro call.  A line is shown when the
+macro is seen, but before the arguments are collected; a second line
+when the arguments have been collected and a third line after the call
+has completed.
+
+@item e
+Show the expansion of each macro call, if it is not void.  This applies
+to all macro calls if the @samp{t} flag is used, otherwise only the
+macros covered by calls of @code{traceon}.
+
+@item f
+Show the name of the current input file in each trace output line.
+
+@item i
+Print a message each time the current input file is changed, giving file
+name and input line number.
+
+@item l
+Show the current input line number in each trace output line.
+
+@item p
+Print a message when a named file is found through the path search
+mechanism (@pxref{Search Path}), giving the actual file name used.
+
+@item q
+Quote actual arguments and macro expansions in the display with the
+current quotes.
+
+@item t
+Trace all macro calls made in this invocation of @code{m4}.
+
+@item x
+Add a unique `macro call id' to each line of the trace output.  This is
+useful in connection with the @samp{c} flag above.
+
+@item V
+A shorthand for all of the above flags.
+@end table
+
+If no flags are specified with the @option{-d} option, the default is
+@samp{aeq}.  The examples throughout this manual assume the default
+flags.
+
+@cindex @acronym{GNU} extensions
+There is a builtin macro @code{debugmode}, which allows on-the-fly control of
+the debugging output format:
+
+@deffn Builtin debugmode (@ovar{flags})
+The argument @var{flags} should be a subset of the letters listed above.
+As special cases, if the argument starts with a @samp{+}, the flags are
+added to the current debug flags, and if it starts with a @samp{-}, they
+are removed.  If no argument is present, all debugging flags are cleared
+(as if no @option{-d} was given), and with an empty argument the flags
+are reset to the default of @samp{aeq}.
+
+The expansion of @code{debugmode} is void.
+@end deffn
+
+@example
+define(`foo', `FOO')
+@result{}
+traceon(`foo')
+@result{}
+debugmode()
+@result{}
+foo
+@error{}m4trace: -1- foo -> `FOO'
+@result{}FOO
+debugmode
+@result{}
+foo
+@error{}m4trace: -1- foo
+@result{}FOO
+debugmode(`+l')
+@result{}
+foo
+@error{}m4trace:8: -1- foo
+@result{}FOO
+@end example
+
+@node Debug Output
+@section Saving debugging output
+
+@cindex saving debugging output
+@cindex debugging output, saving
+@cindex output, saving debugging
+@cindex @acronym{GNU} extensions
+Debug and tracing output can be redirected to files using either the
+@option{--debugfile} option to @code{m4} (@pxref{Debugging options, ,
+Invoking m4}), or with the builtin macro @code{debugfile}:
+
+@deffn Builtin debugfile (@ovar{file})
+Sends all further debug and trace output to @var{file}, opened in append
+mode.  If @var{file} is the empty string, debug and trace output are
+discarded.  If @code{debugfile} is called without any arguments, debug
+and trace output are sent to standard error.  This does not affect
+warnings, error messages, or @code{errprint} output, which are
+always sent to standard error.  If @var{file} cannot be opened, the
+current debug file is unchanged, and an error is issued.
+
+The expansion of @code{debugfile} is void.
+@end deffn
+
+@example
+traceon(`divnum')
+@result{}
+divnum(`extra')
+@error{}m4:stdin:2: Warning: excess arguments to builtin `divnum' ignored
+@error{}m4trace: -1- divnum(`extra') -> `0'
+@result{}0
+debugfile()
+@result{}
+divnum(`extra')
+@error{}m4:stdin:4: Warning: excess arguments to builtin `divnum' ignored
+@result{}0
+debugfile
+@result{}
+divnum
+@error{}m4trace: -1- divnum -> `0'
+@result{}0
+@end example
+
+@node Input Control
+@chapter Input control
+
+This chapter describes various builtin macros for controlling the input
+to @code{m4}.
+
+@menu
+* Dnl::                         Deleting whitespace in input
+* Changequote::                 Changing the quote characters
+* Changecom::                   Changing the comment delimiters
+* Changeword::                  Changing the lexical structure of words
+* M4wrap::                      Saving text until end of input
+@end menu
+
+@node Dnl
+@section Deleting whitespace in input
+
+@cindex deleting whitespace in input
+The builtin @code{dnl} stands for ``Discard to Next Line'':
+
+@deffn Builtin dnl
+All characters, up to and including the next newline, are discarded
+without performing any macro expansion.  A warning is issued if the end
+of the file is encountered without a newline.
+
+The expansion of @code{dnl} is void.
+@end deffn
+
+It is often used in connection with @code{define}, to remove the
+newline that follows the call to @code{define}.  Thus
+
+@example
+define(`foo', `Macro `foo'.')dnl A very simple macro, indeed.
+foo
+@result{}Macro foo.
+@end example
+
+The input up to and including the next newline is discarded, as opposed
+to the way comments are treated (@pxref{Comments}).
+
+Usually, @code{dnl} is immediately followed by an end of line or some
+other whitespace.  @acronym{GNU} @code{m4} will produce a warning diagnostic if
+@code{dnl} is followed by an open parenthesis.  In this case, @code{dnl}
+will collect and process all arguments, looking for a matching close
+parenthesis.  All predictable side effects resulting from this
+collection will take place.  @code{dnl} will return no output.  The
+input following the matching close parenthesis up to and including the
+next newline, on whatever line containing it, will still be discarded.
+
+@example
+dnl(`args are ignored, but side effects occur',
+define(`foo', `like this')) while this text is ignored: undefine(`foo')
+@error{}m4:stdin:1: Warning: excess arguments to builtin `dnl' ignored
+See how `foo' was defined, foo?
+@result{}See how foo was defined, like this?
+@end example
+
+If the end of file is encountered without a newline character, a
+warning is issued and dnl stops consuming input.
+
+@example
+m4wrap(`m4wrap(`2 hi
+')0 hi dnl 1 hi')
+@result{}
+define(`hi', `HI')
+@result{}
+^D
+@error{}m4:stdin:1: Warning: end of file treated as newline
+@result{}0 HI 2 HI
+@end example
+
+@node Changequote
+@section Changing the quote characters
+
+@cindex changing the quote delimiters
+@cindex quote delimiters, changing the
+The default quote delimiters can be changed with the builtin
+@code{changequote}:
+
+@deffn Builtin changequote (@dvar{start, `}, @dvar{end, '})
+This sets @var{start} as the new begin-quote delimiter and @var{end} as
+the new end-quote delimiter.  If both arguments are missing, the default
+quotes (@code{`} and @code{'}) are used.  If @var{start} is void, then
+quoting is disabled.  Otherwise, if @var{end} is missing or void, the
+default end-quote delimiter (@code{'}) is used.  The quote delimiters
+can be of any length.
+
+The expansion of @code{changequote} is void.
+@end deffn
+
+@example
+changequote(`[', `]')
+@result{}
+define([foo], [Macro [foo].])
+@result{}
+foo
+@result{}Macro foo.
+@end example
+
+The quotation strings can safely contain eight-bit characters.
+@ignore
+@comment Yuck.  I know of no clean way to render an 8-bit character in
+@comment both info and dvi.  This example uses the `open-guillemot' and
+@comment `close-guillemot' characters of the Latin-1 character set.
+
+@example
+define(`a', `b')
+@result{}
+«a»
+@result{}«b»
+changequote(`«', `»')
+@result{}
+«a»
+@result{}a
+@end example
+@end ignore
+If no single character is appropriate, @var{start} and @var{end} can be
+of any length.  Other implementations cap the delimiter length to five
+characters, but @acronym{GNU} has no inherent limit.
+
+@example
+changequote(`[[[', `]]]')
+@result{}
+define([[[foo]]], [[[Macro [[[[[foo]]]]].]]])
+@result{}
+foo
+@result{}Macro [[foo]].
+@end example
+
+Calling @code{changequote} with @var{start} as the empty string will
+effectively disable the quoting mechanism, leaving no way to quote text.
+However, using an empty string is not portable, as some other
+implementations of @code{m4} revert to the default quoting, while others
+preserve the prior non-empty delimiter.  If @var{start} is not empty,
+then an empty @var{end} will use the default end-quote delimiter of
+@samp{'}, as otherwise, it would be impossible to end a quoted string.
+Again, this is not portable, as some other @code{m4} implementations
+reuse @var{start} as the end-quote delimiter, while others preserve the
+previous non-empty value.  Omitting both arguments restores the default
+begin-quote and end-quote delimiters; fortunately this behavior is
+portable to all implementations of @code{m4}.
+
+@example
+define(`foo', `Macro `FOO'.')
+@result{}
+changequote(`', `')
+@result{}
+foo
+@result{}Macro `FOO'.
+`foo'
+@result{}`Macro `FOO'.'
+changequote(`,)
+@result{}
+foo
+@result{}Macro FOO.
+@end example
+
+There is no way in @code{m4} to quote a string containing an unmatched
+begin-quote, except using @code{changequote} to change the current
+quotes.
+
+If the quotes should be changed from, say, @samp{[} to @samp{[[},
+temporary quote characters have to be defined.  To achieve this, two
+calls of @code{changequote} must be made, one for the temporary quotes
+and one for the new quotes.
+
+Macros are recognized in preference to the begin-quote string, so if a
+prefix of @var{start} can be recognized as part of a potential macro
+name, the quoting mechanism is effectively disabled.  Unless you use
+@code{changeword} (@pxref{Changeword}), this means that @var{start}
+should not begin with a letter, digit, or @samp{_} (underscore).
+However, even though quoted strings are not recognized, the quote
+characters can still be discerned in macro expansion and in trace
+output.
+
+@example
+define(`echo', `$@@')
+@result{}
+define(`hi', `HI')
+@result{}
+changequote(`q', `Q')
+@result{}
+q hi Q hi
+@result{}q HI Q HI
+echo(hi)
+@result{}qHIQ
+changequote
+@result{}
+changequote(`-', `EOF')
+@result{}
+- hi EOF hi
+@result{} hi  HI
+changequote
+@result{}
+changequote(`1', `2')
+@result{}
+hi1hi2
+@result{}hi1hi2
+hi 1hi2
+@result{}HI hi
+@end example
+
+Quotes are recognized in preference to argument collection.  In
+particular, if @var{start} is a single @samp{(}, then argument
+collection is effectively disabled.  For portability with other
+implementations, it is a good idea to avoid @samp{(}, @samp{,}, and
+@samp{)} as the first character in @var{start}.
+
+@example
+define(`echo', `$#:$@@:')
+@result{}
+define(`hi', `HI')
+@result{}
+changequote(`(',`)')
+@result{}
+echo(hi)
+@result{}0::hi
+changequote
+@result{}
+changequote(`((', `))')
+@result{}
+echo(hi)
+@result{}1:HI:
+echo((hi))
+@result{}0::hi
+changequote
+@result{}
+changequote(`,', `)')
+@result{}
+echo(hi,hi)bye)
+@result{}1:HIhibye:
+@end example
+
+If @var{end} is a prefix of @var{start}, the end-quote will be
+recognized in preference to a nested begin-quote.  In particular,
+changing the quotes to have the same string for @var{start} and
+@var{end} disables nesting of quotes.  When quote nesting is disabled,
+it is impossible to double-quote strings across macro expansions, so
+using the same string is not done very often.
+
+@example
+define(`hi', `HI')
+@result{}
+changequote(`""', `"')
+@result{}
+""hi"""hi"
+@result{}hihi
+""hi" ""hi"
+@result{}hi hi
+""hi"" "hi"
+@result{}hi" "HI"
+changequote
+@result{}
+`hi`hi'hi'
+@result{}hi`hi'hi
+changequote(`"', `"')
+@result{}
+"hi"hi"hi"
+@result{}hiHIhi
+@end example
+
+It is an error if the end of file occurs within a quoted string.
+
+@example
+`hello world'
+@result{}hello world
+`dangling quote
+^D
+@error{}m4:stdin:2: ERROR: end of file in string
+@end example
+
+@node Changecom
+@section Changing the comment delimiters
+
+@cindex changing comment delimiters
+@cindex comment delimiters, changing
+The default comment delimiters can be changed with the builtin
+macro @code{changecom}:
+
+@deffn Builtin changecom (@ovar{start}, @dvar{end, @key{NL}})
+This sets @var{start} as the new begin-comment delimiter and @var{end}
+as the new end-comment delimiter.  If both arguments are missing, or
+@var{start} is void, then comments are disabled.  Otherwise, if
+@var{end} is missing or void, the default end-comment delimiter of
+newline is used.  The comment delimiters can be of any length.
+
+The expansion of @code{changecom} is void.
+@end deffn
+
+@example
+define(`comment', `COMMENT')
+@result{}
+# A normal comment
+@result{}# A normal comment
+changecom(`/*', `*/')
+@result{}
+# Not a comment anymore
+@result{}# Not a COMMENT anymore
+But: /* this is a comment now */ while this is not a comment
+@result{}But: /* this is a comment now */ while this is not a COMMENT
+@end example
+
+@cindex comments, copied to output
+Note how comments are copied to the output, much as if they were quoted
+strings.  If you want the text inside a comment expanded, quote the
+begin-comment delimiter.
+
+Calling @code{changecom} without any arguments, or with @var{start} as
+the empty string, will effectively disable the commenting mechanism.  To
+restore the original comment start of @samp{#}, you must explicitly ask
+for it.  If @var{start} is not empty, then an empty @var{end} will use
+the default end-comment delimiter of newline, as otherwise, it would be
+impossible to end a comment.  However, this is not portable, as some
+other @code{m4} implementations preserve the previous non-empty
+delimiters instead.
+
+@example
+define(`comment', `COMMENT')
+@result{}
+changecom
+@result{}
+# Not a comment anymore
+@result{}# Not a COMMENT anymore
+changecom(`#', `')
+@result{}
+# comment again
+@result{}# comment again
+@end example
+
+The comment strings can safely contain eight-bit characters.
+@ignore
+@comment Yuck.  I know of no clean way to render an 8-bit character in
+@comment both info and dvi.  This example uses the `open-guillemot' and
+@comment `close-guillemot' characters of the Latin-1 character set.
+
+@example
+define(`a', `b')
+@result{}
+«a»
+@result{}«b»
+changecom(`«', `»')
+@result{}
+«a»
+@result{}«a»
+@end example
+@end ignore
+If no single character is appropriate, @var{start} and @var{end} can be
+of any length.  Other implementations cap the delimiter length to five
+characters, but @acronym{GNU} has no inherent limit.
+
+Comments are recognized in preference to macros.  However, this is not
+compatible with other implementations, where macros and even quoting
+takes precedence over comments, so it may change in a future release.
+For portability, this means that @var{start} should not begin with a
+letter, digit, or @samp{_} (underscore), and that neither the
+start-quote nor the start-comment string should be a prefix of the
+other.
+
+@example
+define(`hi', `HI')
+@result{}
+define(`hi1hi2', `hello')
+@result{}
+changecom(`q', `Q')
+@result{}
+q hi Q hi
+@result{}q hi Q HI
+changecom(`1', `2')
+@result{}
+hi1hi2
+@result{}hello
+hi 1hi2
+@result{}HI 1hi2
+@end example
+
+Comments are recognized in preference to argument collection.  In
+particular, if @var{start} is a single @samp{(}, then argument
+collection is effectively disabled.  For portability with other
+implementations, it is a good idea to avoid @samp{(}, @samp{,}, and
+@samp{)} as the first character in @var{start}.
+
+@example
+define(`echo', `$#:$@@:')
+@result{}
+define(`hi', `HI')
+@result{}
+changecom(`(',`)')
+@result{}
+echo(hi)
+@result{}0::(hi)
+changecom
+@result{}
+changecom(`((', `))')
+@result{}
+echo(hi)
+@result{}1:HI:
+echo((hi))
+@result{}0::((hi))
+changecom(`,', `)')
+@result{}
+echo(hi,hi)bye)
+@result{}1:HI,hi)bye:
+@end example
+
+It is an error if the end of file occurs within a comment.
+
+@example
+changecom(`/*', `*/')
+@result{}
+/*dangling comment
+^D
+@error{}m4:stdin:2: ERROR: end of file in comment
+@end example
+
+@node Changeword
+@section Changing the lexical structure of words
+
+@cindex lexical structure of words
+@cindex words, lexical structure of
+@quotation
+The macro @code{changeword} and all associated functionality is
+experimental.  It is only available if the @option{--enable-changeword}
+option was given to @code{configure}, at @acronym{GNU} @code{m4} installation
+time.  The functionality will go away in the future, to be replaced by
+other new features that are more efficient at providing the same
+capabilities.  @emph{Do not rely on it}.  Please direct your comments
+about it the same way you would do for bugs.
+@end quotation
+
+A file being processed by @code{m4} is split into quoted strings, words
+(potential macro names) and simple tokens (any other single character).
+Initially a word is defined by the following regular expression:
+
+@comment ignore
+@example
+[_a-zA-Z][_a-zA-Z0-9]*
+@end example
+
+Using @code{changeword}, you can change this regular expression:
+
+@deffn {Optional builtin} changeword (@var{regex})
+Changes the regular expression for recognizing macro names to be
+@var{regex}.  If @var{regex} is empty, use
+@samp{[_a-zA-Z][_a-zA-Z0-9]*}.  @var{regex} must obey the constraint
+that every prefix of the desired final pattern is also accepted by the
+regular expression.  If @var{regex} contains grouping parentheses, the
+macro invoked is the portion that matched the first group, rather than
+the entire matching string.
+
+The expansion of @code{changeword} is void.
+The macro @code{changeword} is recognized only with parameters.
+@end deffn
+
+Relaxing the lexical rules of @code{m4} might be useful (for example) if
+you wanted to apply translations to a file of numbers:
+
+@example
+ifdef(`changeword', `', `errprint(` skipping: no changeword support
+')m4exit(`77')')dnl
+changeword(`[_a-zA-Z0-9]+')
+@result{}
+define(`1', `0')1
+@result{}0
+@end example
+
+Tightening the lexical rules is less useful, because it will generally
+make some of the builtins unavailable.  You could use it to prevent
+accidental call of builtins, for example:
+
+@example
+ifdef(`changeword', `', `errprint(` skipping: no changeword support
+')m4exit(`77')')dnl
+define(`_indir', defn(`indir'))
+@result{}
+changeword(`_[_a-zA-Z0-9]*')
+@result{}
+esyscmd(`foo')
+@result{}esyscmd(foo)
+_indir(`esyscmd', `echo hi')
+@result{}hi
+@result{}
+@end example
+
+Because @code{m4} constructs its words a character at a time, there
+is a restriction on the regular expressions that may be passed to
+@code{changeword}.  This is that if your regular expression accepts
+@samp{foo}, it must also accept @samp{f} and @samp{fo}.
+
+@example
+ifdef(`changeword', `', `errprint(` skipping: no changeword support
+')m4exit(`77')')dnl
+define(`foo
+', `bar
+')
+@result{}
+dnl This example wants to recognize changeword, dnl, and `foo\n'.
+dnl First, we check that our regexp will match.
+regexp(`changeword', `[cd][a-z]*\|foo[
+]')
+@result{}0
+regexp(`foo
+', `[cd][a-z]*\|foo[
+]')
+@result{}0
+regexp(`f', `[cd][a-z]*\|foo[
+]')
+@result{}-1
+foo
+@result{}foo
+changeword(`[cd][a-z]*\|foo[
+]')
+@result{}
+dnl Even though `foo\n' matches, we forgot to allow `f'.
+foo
+@result{}foo
+changeword(`[cd][a-z]*\|fo*[
+]?')
+@result{}
+dnl Now we can call `foo\n'.
+foo
+@result{}bar
+@end example
+
+@ignore
+@comment One more test of including newline in a macro name; but this
+@comment does not need to be displayed in the manual.  This ensures
+@comment that line numbering is correct when dnl cuts across include
+@comment file boundaries, and when __file__ or __line__ is the last
+@comment token in an include file.
+
+@example
+ifdef(`changeword', `', `errprint(` skipping: no changeword support
+')m4exit(`77')')dnl
+define(`bar
+', defn(`dnl'))dnl
+define(`baz', `dnl
+include(`foo') ignored
+dnl')dnl
+changeword(`\([_a-zA-Z][_a-zA-Z0-9]*\|bar
+\)')
+@result{}
+__file__:__line__
+@result{}stdin:10
+include(`foo') ignored
+__file__:__line__
+@result{}stdin:12
+baz ignored
+__file__:__line__
+@result{}stdin:14
+define(`bar
+', defn(`__file__'))
+@result{}
+include(`foo')
+@result{}../examples/foo
+define(`bar
+', defn(`__line__'))
+@result{}
+include(`foo')
+@result{}1
+__file__:__line__
+@result{}stdin:21
+@end example
+@end ignore
+
+@code{changeword} has another function.  If the regular expression
+supplied contains any grouped subexpressions, then text outside
+the first of these is discarded before symbol lookup.  So:
+
+@example
+ifdef(`changeword', `', `errprint(` skipping: no changeword support
+')m4exit(`77')')dnl
+ifdef(`__unix__', ,
+      `errprint(` skipping: syscmd does not have unix semantics
+')m4exit(`77')')dnl
+changecom(`/*', `*/')dnl
+define(`foo', `bar')dnl
+changeword(`#\([_a-zA-Z0-9]*\)')
+@result{}
+#esyscmd(`echo foo \#foo')
+@result{}foo bar
+@result{}
+@end example
+
+@code{m4} now requires a @samp{#} mark at the beginning of every
+macro invocation, so one can use @code{m4} to preprocess plain
+text without losing various words like @samp{divert}.
+
+In @code{m4}, macro substitution is based on text, while in @TeX{}, it
+is based on tokens.  @code{changeword} can throw this difference into
+relief.  For example, here is the same idea represented in @TeX{} and
+@code{m4}.  First, the @TeX{} version:
+
+@comment ignore
+@example
+\def\a@{\message@{Hello@}@}
+\catcode`\@@=0
+\catcode`\\=12
+@@a
+@@bye
+@result{}Hello
+@end example
+
+@noindent
+Then, the @code{m4} version:
+
+@example
+ifdef(`changeword', `', `errprint(` skipping: no changeword support
+')m4exit(`77')')dnl
+define(`a', `errprint(`Hello')')dnl
+changeword(`@@\([_a-zA-Z0-9]*\)')
+@result{}
+@@a
+@result{}errprint(Hello)
+@end example
+
+In the @TeX{} example, the first line defines a macro @code{a} to
+print the message @samp{Hello}.  The second line defines @key{@@} to
+be usable instead of @key{\} as an escape character.  The third line
+defines @key{\} to be a normal printing character, not an escape.
+The fourth line invokes the macro @code{a}.  So, when @TeX{} is run
+on this file, it displays the message @samp{Hello}.
+
+When the @code{m4} example is passed through @code{m4}, it outputs
+@samp{errprint(Hello)}.  The reason for this is that @TeX{} does
+lexical analysis of macro definition when the macro is @emph{defined}.
+@code{m4} just stores the text, postponing the lexical analysis until
+the macro is @emph{used}.
+
+You should note that using @code{changeword} will slow @code{m4} down
+by a factor of about seven, once it is changed to something other
+than the default regular expression.  You can invoke @code{changeword}
+with the empty string to restore the default word definition, and regain
+the parsing speed.
+
+@node M4wrap
+@section Saving text until end of input
+
+@cindex saving input
+@cindex input, saving
+It is possible to `save' some text until the end of the normal input has
+been seen.  Text can be saved, to be read again by @code{m4} when the
+normal input has been exhausted.  This feature is normally used to
+initiate cleanup actions before normal exit, e.g., deleting temporary
+files.
+
+To save input text, use the builtin @code{m4wrap}:
+
+@deffn Builtin m4wrap (@var{string}, @dots{})
+Stores @var{string} in a safe place, to be reread when end of input is
+reached.  As a @acronym{GNU} extension, additional arguments are
+concatenated with a space to the @var{string}.
+
+The expansion of @code{m4wrap} is void.
+The macro @code{m4wrap} is recognized only with parameters.
+@end deffn
+
+@example
+define(`cleanup', `This is the `cleanup' action.
+')
+@result{}
+m4wrap(`cleanup')
+@result{}
+This is the first and last normal input line.
+@result{}This is the first and last normal input line.
+^D
+@result{}This is the cleanup action.
+@end example
+
+The saved input is only reread when the end of normal input is seen, and
+not if @code{m4exit} is used to exit @code{m4}.
+
+@comment FIXME: this contradicts POSIX, which requires that "If the
+@comment m4wrap macro is used multiple times, the arguments specified
+@comment shall be processed in the order in which the m4wrap macros were
+@comment processed."
+It is safe to call @code{m4wrap} from saved text, but then the order in
+which the saved text is reread is undefined.  If @code{m4wrap} is not used
+recursively, the saved pieces of text are reread in the opposite order
+in which they were saved (LIFO---last in, first out).  However, this
+behavior is likely to change in a future release, to match
+@acronym{POSIX}, so you should not depend on this order.
+
+Here is an example of implementing a factorial function using
+@code{m4wrap}:
+
+@example
+define(`f', `ifelse(`$1', `0', `Answer: 0!=1
+', eval(`$1>1'), `0', `Answer: $2$1=eval(`$2$1')
+', `m4wrap(`f(decr(`$1'), `$2$1*')')')')
+@result{}
+f(`10')
+@result{}
+^D
+@result{}Answer: 10*9*8*7*6*5*4*3*2*1=3628800
+@end example
+
+Invocations of @code{m4wrap} at the same recursion level are
+concatenated and rescanned as usual:
+
+@example
+define(`aa', `AA
+')
+@result{}
+m4wrap(`a')m4wrap(`a')
+@result{}
+^D
+@result{}AA
+@end example
+
+@noindent
+however, the transition between recursion levels behaves like an end of
+file condition between two input files.
+
+@example
+m4wrap(`m4wrap(`)')len(abc')
+@result{}
+^D
+@error{}m4:stdin:1: ERROR: end of file in argument list
+@end example
+
+@node File Inclusion
+@chapter File inclusion
+
+@cindex file inclusion
+@cindex inclusion, of files
+
+@code{m4} allows you to include named files at any point in the input.
+
+@menu
+* Include::                     Including named files
+* Search Path::                 Searching for include files
+@end menu
+
+@node Include
+@section Including named files
+
+There are two builtin macros in @code{m4} for including files:
+
+@deffn Builtin include (@var{file})
+@deffnx Builtin sinclude (@var{file})
+Both macros cause the file named @var{file} to be read by
+@code{m4}.  When the end of the file is reached, input is resumed from
+the previous input file.
+
+The expansion of @code{include} and @code{sinclude} is therefore the
+contents of @var{file}.
+
+If @var{file} does not exist (or cannot be read), the expansion is void,
+and @code{include} will fail with an error while @code{sinclude} is
+silent.  The empty string counts as a file that does not exist.
+
+The macros @code{include} and @code{sinclude} are recognized only with
+parameters.
+@end deffn
+
+@example
+include(`none')
+@error{}m4:stdin:1: cannot open `none': No such file or directory
+@result{}
+include()
+@error{}m4:stdin:2: cannot open `': No such file or directory
+@result{}
+sinclude(`none')
+@result{}
+sinclude()
+@result{}
+@end example
+
+The rest of this section assumes that @code{m4} is invoked with the
+@option{-I} option (@pxref{Preprocessor features, , Invoking m4})
+pointing to the @file{m4-@value{VERSION}/@/examples}
+directory shipped as part of the @acronym{GNU} @code{m4} package.  The
+file @file{m4-@value{VERSION}/@/examples/@/incl.m4} in the distribution
+contains the lines:
+
+@comment ignore
+@example
+Include file start
+foo
+Include file end
+@end example
+
+Normally file inclusion is used to insert the contents of a file
+into the input stream.  The contents of the file will be read by
+@code{m4} and macro calls in the file will be expanded:
+
+@example
+define(`foo', `FOO')
+@result{}
+include(`incl.m4')
+@result{}Include file start
+@result{}FOO
+@result{}Include file end
+@result{}
+@end example
+
+The fact that @code{include} and @code{sinclude} expand to the contents
+of the file can be used to define macros that operate on entire files.
+Here is an example, which defines @samp{bar} to expand to the contents
+of @file{incl.m4}:
+
+@example
+define(`bar', include(`incl.m4'))
+@result{}
+This is `bar':  >>bar<<
+@result{}This is bar:  >>Include file start
+@result{}foo
+@result{}Include file end
+@result{}<<
+@end example
+
+This use of @code{include} is not trivial, though, as files can contain
+quotes, commas, and parentheses, which can interfere with the way the
+@code{m4} parser works.  @acronym{GNU} @code{m4} seamlessly concatenates
+the file contents with the next character, even if the included file
+ended in the middle of a comment, string, or macro call.  These
+conditions are only treated as end of file errors if specified as input
+files on the command line.
+
+In @acronym{GNU} @code{m4}, an alternative method of reading files is
+using @code{undivert} (@pxref{Undivert}) on a named file.
+
+@node Search Path
+@section Searching for include files
+
+@cindex search path for included files
+@cindex included files, search path for
+@cindex @acronym{GNU} extensions
+@acronym{GNU} @code{m4} allows included files to be found in other directories
+than the current working directory.
+
+If the @option{--prepend-include} or @option{-B} command-line option was
+provided (@pxref{Preprocessor features, , Invoking m4}), those
+directories are searched first, in reverse order that those options were
+listed on the command line.  Then @code{m4} looks in the current working
+directory.  Next comes the directories specified with the
+@option{--include} or @option{-I} option, in the order found on the
+command line.  Finally, if the @env{M4PATH} environment variable is set,
+it is expected to contain a colon-separated list of directories, which
+will be searched in order.
+
+If the automatic search for include-files causes trouble, the @samp{p}
+debug flag (@pxref{Debug Levels}) can help isolate the problem.
+
+@node Diversions
+@chapter Diverting and undiverting output
+
+Diversions are a way of temporarily saving output.  The output of
+@code{m4} can at any time be diverted to a temporary file, and be
+reinserted into the output stream, @dfn{undiverted}, again at a later
+time.
+
+Numbered diversions are counted from 0 upwards, diversion number 0
+being the normal output stream.  The number of simultaneous diversions
+is limited mainly by the memory used to describe them, because @acronym{GNU}
+@code{m4} tries to keep diversions in memory.  However, there is a
+limit to the overall memory usable by all diversions taken altogether
+(512K, currently).  When this maximum is about to be exceeded,
+a temporary file is opened to receive the contents of the biggest
+diversion still in memory, freeing this memory for other diversions.
+When creating the temporary file, @code{m4} honors the value of the
+environment variable @env{TMPDIR}, and falls back to @file{/tmp}.
+So, it is theoretically possible that the number and aggregate size of
+diversions is limited only by available disk space.
+
+@ignore
+@comment We need to test spilled diversions, but don't need to expose
+@comment this highly repetitive test in the manual.
+
+@example
+divert(`-1')define(`f', `.')
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+divert`'dnl
+len(f)
+@result{}1048576
+divert(`1')
+f
+divert(`-1')undivert
+@end example
+
+@comment Another test of spilled diversions.
+
+@example
+divert(`-1')define(`f', `.')
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+define(`f', defn(`f')defn(`f'))
+divert`'dnl
+len(f)
+@result{}1048576
+divert(`1')
+f
+m4exit
+@end example
+@end ignore
+
+Diversions make it possible to generate output in a different order than
+the input was read.  It is possible to implement topological sorting
+dependencies.  For example, @acronym{GNU} Autoconf makes use of
+diversions under the hood to ensure that the expansion of a prerequisite
+macro appears in the output prior to the expansion of a dependent macro,
+regardless of which order the two macros were invoked in the user's
+input file.
+
+@menu
+* Divert::                      Diverting output
+* Undivert::                    Undiverting output
+* Divnum::                      Diversion numbers
+* Cleardivert::                 Discarding diverted text
+@end menu
+
+@node Divert
+@section Diverting output
+
+@cindex diverting output to files
+@cindex output, diverting to files
+@cindex files, diverting output to
+Output is diverted using @code{divert}:
+
+@deffn Builtin divert (@dvar{number, 0})
+The current diversion is changed to @var{number}.  If @var{number} is left
+out or empty, it is assumed to be zero.  If @var{number} cannot be
+parsed, the diversion is unchanged.
+
+The expansion of @code{divert} is void.
+@end deffn
+
+When all the @code{m4} input will have been processed, all existing
+diversions are automatically undiverted, in numerical order.
+
+@example
+divert(`1')
+This text is diverted.
+divert
+@result{}
+This text is not diverted.
+@result{}This text is not diverted.
+^D
+@result{}
+@result{}This text is diverted.
+@end example
+
+Several calls of @code{divert} with the same argument do not overwrite
+the previous diverted text, but append to it.  Diversions are printed
+after any wrapped text is expanded.
+
+@example
+define(`text', `TEXT')
+@result{}
+divert(`1')`diverted text.'
+divert
+@result{}
+m4wrap(`Wrapped text preceeds ')
+@result{}
+^D
+@result{}Wrapped TEXT preceeds diverted text.
+@end example
+
+If output is diverted to a negative diversion, it is simply discarded.
+This can be used to suppress unwanted output.  A common example of
+unwanted output is the trailing newlines after macro definitions.  Here
+is a common programming idiom in @code{m4} for avoiding them.
+
+@example
+divert(`-1')
+define(`foo', `Macro `foo'.')
+define(`bar', `Macro `bar'.')
+divert
+@result{}
+@end example
+
+@cindex @acronym{GNU} extensions
+Traditional implementations only supported ten diversions.  But as a
+@acronym{GNU} extension, diversion numbers can be as large as positive
+integers will allow, rather than treating a multi-digit diversion number
+as a request to discard text.
+
+@example
+divert(eval(`1<<28'))world
+divert(`2')hello
+^D
+@result{}hello
+@result{}world
+@end example
+
+Note that @code{divert} is an English word, but also an active macro
+without arguments.  When processing plain text, the word might appear in
+normal text and be unintentionally swallowed as a macro invocation.  One
+way to avoid this is to use the @option{-P} option to rename all
+builtins (@pxref{Operation modes, , Invoking m4}).  Another is to write
+a wrapper that requires a parameter to be recognized.
+
+@example
+We decided to divert the stream for irrigation.
+@result{}We decided to  the stream for irrigation.
+define(`divert', `ifelse(`$#', `0', ``$0'', `builtin(`$0', $@@)')')
+@result{}
+divert(`-1')
+Ignored text.
+divert(`0')
+@result{}
+We decided to divert the stream for irrigation.
+@result{}We decided to divert the stream for irrigation.
+@end example
+
+@node Undivert
+@section Undiverting output
+
+Diverted text can be undiverted explicitly using the builtin
+@code{undivert}:
+
+@deffn Builtin undivert (@ovar{diversions@dots{}})
+Undiverts the numeric @var{diversions} given by the arguments, in the
+order given.  If no arguments are supplied, all diversions are
+undiverted, in numerical order.
+
+As a @acronym{GNU} extension, @var{diversions} may contain non-numeric
+strings, which are treated as the names of files to copy into the output
+without expansion.  A warning is issued if a file could not be opened.
+
+The expansion of @code{undivert} is void.
+@end deffn
+
+@example
+divert(`1')
+This text is diverted.
+divert
+@result{}
+This text is not diverted.
+@result{}This text is not diverted.
+undivert(`1')
+@result{}
+@result{}This text is diverted.
+@result{}
+@end example
+
+Notice the last two blank lines.  One of them comes from the newline
+following @code{undivert}, the other from the newline that followed the
+@code{divert}!  A diversion often starts with a blank line like this.
+
+When diverted text is undiverted, it is @emph{not} reread by @code{m4},
+but rather copied directly to the current output, and it is therefore
+not an error to undivert into a diversion.  Undiverting the empty string
+is the same as specifying diversion 0; in either case nothing happens
+since the output has already been flushed.
+
+@example
+divert(`1')diverted text
+divert
+@result{}
+undivert()
+@result{}
+undivert(`0')
+@result{}
+undivert
+@result{}diverted text
+@result{}
+@end example
+
+When a diversion has been undiverted, the diverted text is discarded,
+and it is not possible to bring back diverted text more than once.
+
+@example
+divert(`1')
+This text is diverted first.
+divert(`0')undivert(`1')dnl
+@result{}
+@result{}This text is diverted first.
+undivert(`1')
+@result{}
+divert(`1')
+This text is also diverted but not appended.
+divert(`0')undivert(`1')dnl
+@result{}
+@result{}This text is also diverted but not appended.
+@end example
+
+Attempts to undivert the current diversion are silently ignored.  Thus,
+when the current diversion is not 0, the current diversion does not get
+rearranged among the other diversions.
+
+@example
+divert(`1')one
+divert(`2')two
+divert(`3')three
+divert(`2')undivert`'dnl
+divert`'undivert`'dnl
+@result{}two
+@result{}one
+@result{}three
+@end example
+
+@cindex @acronym{GNU} extensions
+@cindex file inclusion
+@cindex inclusion, of files
+@acronym{GNU} @code{m4} allows named files to be undiverted.  Given a
+non-numeric
+argument, the contents of the file named will be copied, uninterpreted, to
+the current output.  This complements the builtin @code{include}
+(@pxref{Include}).  To illustrate the difference, the file
+@file{m4-@value{VERSION}/@/examples/@/foo} contains the word @samp{bar}:
+
+@example
+define(`bar', `BAR')
+@result{}
+undivert(`foo')
+@result{}bar
+@result{}
+include(`foo')
+@result{}BAR
+@result{}
+@end example
+
+If the file is not found (or cannot be read), an error message is
+issued, and the expansion is void.
+
+@node Divnum
+@section Diversion numbers
+
+@cindex diversion numbers
+The current diversion is tracked by the builtin @code{divnum}:
+
+@deffn Builtin divnum
+Expands to the number of the current diversion.
+@end deffn
+
+@example
+Initial divnum
+@result{}Initial 0
+divert(`1')
+Diversion one: divnum
+divert(`2')
+Diversion two: divnum
+^D
+@result{}
+@result{}Diversion one: 1
+@result{}
+@result{}Diversion two: 2
+@end example
+
+@node Cleardivert
+@section Discarding diverted text
+
+@cindex discarding diverted text
+@cindex diverted text, discarding
+Often it is not known, when output is diverted, whether the diverted
+text is actually needed.  Since all non-empty diversion are brought back
+on the main output stream when the end of input is seen, a method of
+discarding a diversion is needed.  If all diversions should be
+discarded, the easiest is to end the input to @code{m4} with
+@samp{divert(`-1')} followed by an explicit @samp{undivert}:
+
+@example
+divert(`1')
+Diversion one: divnum
+divert(`2')
+Diversion two: divnum
+divert(`-1')
+undivert
+^D
+@end example
+
+@noindent
+No output is produced at all.
+
+Clearing selected diversions can be done with the following macro:
+
+@deffn Composite cleardivert (@ovar{diversions@dots{}})
+Discard the contents of each of the listed numeric @var{diversions}.
+@end deffn
+
+@example
+define(`cleardivert',
+`pushdef(`_n', divnum)divert(`-1')undivert($@@)divert(_n)popdef(`_n')')
+@result{}
+@end example
+
+It is called just like @code{undivert}, but the effect is to clear the
+diversions, given by the arguments.  (This macro has a nasty bug!  You
+should try to see if you can find it and correct it; or @pxref{Improved
+cleardivert, , Answers}).
+
+@node Text handling
+@chapter Macros for text handling
+
+There are a number of builtins in @code{m4} for manipulating text in
+various ways, extracting substrings, searching, substituting, and so on.
+
+@menu
+* Len::                         Calculating length of strings
+* Index macro::                 Searching for substrings
+* Regexp::                      Searching for regular expressions
+* Substr::                      Extracting substrings
+* Translit::                    Translating characters
+* Patsubst::                    Substituting text by regular expression
+* Format::                      Formatting strings (printf-like)
+@end menu
+
+@node Len
+@section Calculating length of strings
+
+@cindex length of strings
+@cindex strings, length of
+The length of a string can be calculated by @code{len}:
+
+@deffn Builtin len (@var{string})
+Expands to the length of @var{string}, as a decimal number.
+
+The macro @code{len} is recognized only with parameters.
+@end deffn
+
+@example
+len()
+@result{}0
+len(`abcdef')
+@result{}6
+@end example
+
+@node Index macro
+@section Searching for substrings
+
+Searching for substrings is done with @code{index}:
+
+@deffn Builtin index (@var{string}, @var{substring})
+Expands to the index of the first occurrence of @var{substring} in
+@var{string}.  The first character in @var{string} has index 0.  If
+@var{substring} does not occur in @var{string}, @code{index} expands to
+@samp{-1}.
+
+The macro @code{index} is recognized only with parameters.
+@end deffn
+
+@example
+index(`gnus, gnats, and armadillos', `nat')
+@result{}7
+index(`gnus, gnats, and armadillos', `dag')
+@result{}-1
+@end example
+
+Omitting @var{substring} evokes a warning, but still produces output.
+
+@example
+index(`abc')
+@error{}m4:stdin:1: Warning: too few arguments to builtin `index'
+@result{}0
+@end example
+
+@node Regexp
+@section Searching for regular expressions
+
+@cindex regular expressions
+@cindex @acronym{GNU} extensions
+Searching for regular expressions is done with the builtin
+@code{regexp}:
+
+@deffn Builtin regexp (@var{string}, @var{regexp}, @ovar{replacement})
+Searches for @var{regexp} in @var{string}.  The syntax for regular
+expressions is the same as in @acronym{GNU} Emacs.
+@ifnothtml
+@xref{Regexps, , Syntax of Regular Expressions, emacs, The GNU Emacs
+Manual}.
+@end ifnothtml
+@ifhtml
+See
+@uref{http://www.gnu.org/@/software/@/emacs/@/manual/@/emacs.html#Regexps,
+Syntax of Regular Expressions} in the @acronym{GNU} Emacs Manual.
+@end ifhtml
+
+If @var{replacement} is omitted, @code{regexp} expands to the index of
+the first match of @var{regexp} in @var{string}.  If @var{regexp} does
+not match anywhere in @var{string}, it expands to -1.
+
+If @var{replacement} is supplied, and there was a match, @code{regexp}
+changes the expansion to this argument, with @samp{\@var{n}} substituted
+by the text matched by the @var{n}th parenthesized sub-expression of
+@var{regexp}, up to nine sub-expressions.  The escape @samp{\&} is
+replaced by the text of the entire regular expression matched.  For
+all other characters, @samp{\} treats the next character literally.  A
+warning is issued if there were fewer sub-expressions than the
+@samp{\@var{n}} requested, or if there is a trailing @samp{\}.  If there
+was no match, @code{regexp} expands to the empty string.
+
+The macro @code{regexp} is recognized only with parameters.
+@end deffn
+
+@example
+regexp(`GNUs not Unix', `\<[a-z]\w+')
+@result{}5
+regexp(`GNUs not Unix', `\<Q\w*')
+@result{}-1
+regexp(`GNUs not Unix', `\w\(\w+\)$', `*** \& *** \1 ***')
+@result{}*** Unix *** nix ***
+regexp(`GNUs not Unix', `\<Q\w*', `*** \& *** \1 ***')
+@result{}
+@end example
+
+Here are some more examples on the handling of backslash:
+
+@example
+regexp(`abc', `\(b\)', `\\\10\a')
+@result{}\b0a
+regexp(`abc', `b', `\1\')
+@error{}m4:stdin:2: Warning: sub-expression 1 not present
+@error{}m4:stdin:2: Warning: trailing \ ignored in replacement
+@result{}
+regexp(`abc', `\(\(d\)?\)\(c\)', `\1\2\3\4\5\6')
+@error{}m4:stdin:3: Warning: sub-expression 4 not present
+@error{}m4:stdin:3: Warning: sub-expression 5 not present
+@error{}m4:stdin:3: Warning: sub-expression 6 not present
+@result{}c
+@end example
+
+Omitting @var{regexp} evokes a warning, but still produces output.
+
+@example
+regexp(`abc')
+@error{}m4:stdin:1: Warning: too few arguments to builtin `regexp'
+@result{}0
+@end example
+
+@node Substr
+@section Extracting substrings
+
+@cindex extracting substrings
+@cindex substrings, extracting
+Substrings are extracted with @code{substr}:
+
+@deffn Builtin substr (@var{string}, @var{from}, @ovar{length})
+Expands to the substring of @var{string}, which starts at index
+@var{from}, and extends for @var{length} characters, or to the end of
+@var{string}, if @var{length} is omitted.  The starting index of a string
+is always 0.  The expansion is empty if there is an error parsing
+@var{from} or @var{length}, if @var{from} is beyond the end of
+@var{string}, or if @var{length} is negative.
+
+The macro @code{substr} is recognized only with parameters.
+@end deffn
+
+@example
+substr(`gnus, gnats, and armadillos', `6')
+@result{}gnats, and armadillos
+substr(`gnus, gnats, and armadillos', `6', `5')
+@result{}gnats
+@end example
+
+Omitting @var{from} evokes a warning, but still produces output.
+
+@example
+substr(`abc')
+@error{}m4:stdin:1: Warning: too few arguments to builtin `substr'
+@result{}abc
+substr(`abc',)
+@error{}m4:stdin:2: empty string treated as 0 in builtin `substr'
+@result{}abc
+@end example
+
+@node Translit
+@section Translating characters
+
+@cindex translating characters
+@cindex characters, translating
+Character translation is done with @code{translit}:
+
+@deffn Builtin translit (@var{string}, @var{chars}, @ovar{replacement})
+Expands to @var{string}, with each character that occurs in
+@var{chars} translated into the character from @var{replacement} with
+the same index.
+
+If @var{replacement} is shorter than @var{chars}, the excess characters
+of @var{chars} are deleted from the expansion; if @var{chars} is
+shorter, the excess characters in @var{replacement} are silently
+ignored.  If @var{replacement} is omitted, all characters in
+@var{string} that are present in @var{chars} are deleted from the
+expansion.  If a character appears more than once in @var{chars}, only
+the first instance is used in making the translation.  Only a single
+translation pass is made, even if characters in @var{replacement} also
+appear in @var{chars}.
+
+As a @acronym{GNU} extension, both @var{chars} and @var{replacement} can
+contain character-ranges, e.g., @samp{a-z} (meaning all lowercase
+letters) or @samp{0-9} (meaning all digits).  To include a dash @samp{-}
+in @var{chars} or @var{replacement}, place it first or last in the
+entire string, or as the last character of a range.  Back-to-back ranges
+can share a common endpoint.  It is not an error for the last character
+in the range to be `larger' than the first.  In that case, the range
+runs backwards, i.e., @samp{9-0} means the string @samp{9876543210}.
+The expansion of a range is dependent on the underlying encoding of
+characters, so using ranges is not always portable between machines.
+
+The macro @code{translit} is recognized only with parameters.
+@end deffn
+
+@example
+translit(`GNUs not Unix', `A-Z')
+@result{}s not nix
+translit(`GNUs not Unix', `a-z', `A-Z')
+@result{}GNUS NOT UNIX
+translit(`GNUs not Unix', `A-Z', `z-a')
+@result{}tmfs not fnix
+translit(`+,-12345', `+--1-5', `<;>a-c-a')
+@result{}<;>abcba
+translit(`abcdef', `aabdef', `bcged')
+@result{}bgced
+@end example
+
+In the @sc{ascii} encoding, the first example deletes all uppercase
+letters, the second converts lowercase to uppercase, and the third
+`mirrors' all uppercase letters, while converting them to lowercase.
+The two first cases are by far the most common, even though they are not
+portable to @sc{ebcdic} or other encodings.  The fourth example shows a
+range ending in @samp{-}, as well as back-to-back ranges.  The final
+example shows that @samp{a} is mapped to @samp{b}, not @samp{c}; the
+resulting @samp{b} is not further remapped to @samp{g}; the @samp{d} and
+@samp{e} are swapped, and the @samp{f} is discarded.
+
+@ignore
+@comment No need to fight 8-bit characters, as it is difficult to get
+@comment rendering right in both info and dvi.
+
+@example
+translit(`«abc~', `~-»')
+@result{}abc
+@end example
+@end ignore
+
+Omitting @var{chars} evokes a warning, but still produces output.
+
+@example
+translit(`abc')
+@error{}m4:stdin:1: Warning: too few arguments to builtin `translit'
+@result{}abc
+@end example
+
+@node Patsubst
+@section Substituting text by regular expression
+
+@cindex regular expressions
+@cindex pattern substitution
+@cindex substitution by regular expression
+@cindex @acronym{GNU} extensions
+Global substitution in a string is done by @code{patsubst}:
+
+@deffn Builtin patsubst (@var{string}, @var{regexp}, @ovar{replacement})
+Searches @var{string} for matches of @var{regexp}, and substitutes
+@var{replacement} for each match.  The syntax for regular expressions
+is the same as in @acronym{GNU} Emacs (@pxref{Regexp}).
+
+The parts of @var{string} that are not covered by any match of
+@var{regexp} are copied to the expansion.  Whenever a match is found, the
+search proceeds from the end of the match, so a character from
+@var{string} will never be substituted twice.  If @var{regexp} matches a
+string of zero length, the start position for the search is incremented,
+to avoid infinite loops.
+
+When a replacement is to be made, @var{replacement} is inserted into
+the expansion, with @samp{\@var{n}} substituted by the text matched by
+the @var{n}th parenthesized sub-expression of @var{patsubst}, for up to
+nine sub-expressions.  The escape @samp{\&} is replaced by the text of
+the entire regular expression matched.  For all other characters,
+@samp{\} treats the next character literally.  A warning is issued if
+there were fewer sub-expressions than the @samp{\@var{n}} requested, or
+if there is a trailing @samp{\}.
+
+The @var{replacement} argument can be omitted, in which case the text
+matched by @var{regexp} is deleted.
+
+The macro @code{patsubst} is recognized only with parameters.
+@end deffn
+
+@example
+patsubst(`GNUs not Unix', `^', `OBS: ')
+@result{}OBS: GNUs not Unix
+patsubst(`GNUs not Unix', `\<', `OBS: ')
+@result{}OBS: GNUs OBS: not OBS: Unix
+patsubst(`GNUs not Unix', `\w*', `(\&)')
+@result{}(GNUs)() (not)() (Unix)()
+patsubst(`GNUs not Unix', `\w+', `(\&)')
+@result{}(GNUs) (not) (Unix)
+patsubst(`GNUs not Unix', `[A-Z][a-z]+')
+@result{}GN not@w{ }
+patsubst(`GNUs not Unix', `not', `NOT\')
+@error{}m4:stdin:6: Warning: trailing \ ignored in replacement
+@result{}GNUs NOT Unix
+@end example
+
+Here is a slightly more realistic example, which capitalizes individual
+word or whole sentences, by substituting calls of the macros
+@code{upcase} and @code{downcase} into the strings.
+
+@deffn Composite upcase (@var{text})
+@deffnx Composite downcase (@var{text})
+@deffnx Composite capitalize (@var{text})
+Expand to @var{text}, but with capitalization changed: @code{upcase}
+changes all letters to upper case, @code{downcase} changes all letters
+to lower case, and @code{capitalize} changes the first character of each
+word to upper case and the remaining characters to lower case.
+@end deffn
+
+@example
+define(`upcase', `translit(`$*', `a-z', `A-Z')')dnl
+define(`downcase', `translit(`$*', `A-Z', `a-z')')dnl
+define(`capitalize1',
+       `regexp(`$1', `^\(\w\)\(\w*\)',
+               `upcase(`\1')`'downcase(`\2')')')dnl
+define(`capitalize',
+       `patsubst(`$1', `\w+', `capitalize1(`\&')')')dnl
+capitalize(`GNUs not Unix')
+@result{}Gnus Not Unix
+@end example
+
+While @code{regexp} replaces the whole input with the replacement as
+soon as there is a match, @code{patsubst} replaces each
+@emph{occurrence} of a match and preserves non-matching pieces:
+
+@example
+define(`patreg',
+`patsubst($@@)
+regexp($@@)')dnl
+patreg(`bar foo baz Foo', `foo\|Foo', `FOO')
+@result{}bar FOO baz FOO
+@result{}FOO
+patreg(`aba abb 121', `\(.\)\(.\)\1', `\2\1\2')
+@result{}bab abb 212
+@result{}bab
+@end example
+
+Omitting @var{regexp} evokes a warning, but still produces output.
+
+@example
+patsubst(`abc')
+@error{}m4:stdin:1: Warning: too few arguments to builtin `patsubst'
+@result{}abc
+@end example
+
+@node Format
+@section Formatted output
+
+@cindex formatted output
+@cindex output, formatted
+@cindex @acronym{GNU} extensions
+Formatted output can be made with @code{format}:
+
+@deffn Builtin format (@var{format-string}, @dots{})
+Works much like the C function @code{printf}.  The first argument
+@var{format-string} can contain @samp{%} specifications which are
+satisfied by additional arguments, and the expansion of @code{format} is
+the formatted string.
+
+The macro @code{format} is recognized only with parameters.
+@end deffn
+
+Its use is best described by a few examples:
+
+@example
+define(`foo', `The brown fox jumped over the lazy dog')
+@result{}
+format(`The string "%s" uses %d characters', foo, len(foo))
+@result{}The string "The brown fox jumped over the lazy dog" uses 38 characters
+format(`%.0f', `56789.9876')
+@result{}56790
+len(format(`%-*X', `300', `1'))
+@result{}300
+@end example
+
+Using the @code{forloop} macro defined earlier (@pxref{Forloop}), this
+example shows how @code{format} can be used to produce tabular output.
+
+@example
+include(`forloop.m4')
+@result{}
+forloop(`i', `1', `10', `format(`%6d squared is %10d
+', i, eval(i**2))')
+@result{}     1 squared is          1
+@result{}     2 squared is          4
+@result{}     3 squared is          9
+@result{}     4 squared is         16
+@result{}     5 squared is         25
+@result{}     6 squared is         36
+@result{}     7 squared is         49
+@result{}     8 squared is         64
+@result{}     9 squared is         81
+@result{}    10 squared is        100
+@result{}
+@end example
+
+The builtin @code{format} is modeled after the ANSI C @samp{printf}
+function, and supports these @samp{%} specifiers: @samp{c},
+@samp{s}, @samp{d}, @samp{o}, @samp{x}, @samp{X}, @samp{u}, @samp{e},
+@samp{E}, @samp{f}, @samp{F}, @samp{g}, @samp{G}, and @samp{%}; it
+supports field widths and precisions, and the
+modifiers @samp{+}, @samp{-}, @samp{@w{ }}, @samp{0}, @samp{#}, @samp{h} and
+@samp{l}.  For more details on the functioning of @code{printf}, see the
+C Library Manual.
+
+For now, unrecognized specifiers are silently ignored, but it is
+anticipated that a future release of @acronym{GNU} @code{m4} will support more
+specifiers, and give warnings when problems are encountered.  Likewise,
+escape sequences are not yet recognized.
+
+@node Arithmetic
+@chapter Macros for doing arithmetic
+
+@cindex arithmetic
+@cindex integer arithmetic
+Integer arithmetic is included in @code{m4}, with a C-like syntax.  As
+convenient shorthands, there are builtins for simple increment and
+decrement operations.
+
+@menu
+* Incr::                        Decrement and increment operators
+* Eval::                        Evaluating integer expressions
+@end menu
+
+@node Incr
+@section Decrement and increment operators
+
+@cindex decrement operator
+@cindex increment operator
+Increment and decrement of integers are supported using the builtins
+@code{incr} and @code{decr}:
+
+@deffn Builtin incr (@var{number})
+@deffnx Builtin decr (@var{number})
+Expand to the numerical value of @var{number}, incremented
+or decremented, respectively, by one.  Except for the empty string, the
+expansion is empty if @var{number} could not be parsed.
+
+The macros @code{incr} and @code{decr} are recognized only with
+parameters.
+@end deffn
+
+@example
+incr(`4')
+@result{}5
+decr(`7')
+@result{}6
+incr()
+@error{}m4:stdin:3: empty string treated as 0 in builtin `incr'
+@result{}1
+decr()
+@error{}m4:stdin:4: empty string treated as 0 in builtin `decr'
+@result{}-1
+@end example
+
+@node Eval
+@section Evaluating integer expressions
+
+@cindex integer expression evaluation
+@cindex evaluation, of integer expressions
+@cindex expressions, evaluation of integer
+Integer expressions are evaluated with @code{eval}:
+
+@deffn Builtin eval (@var{expression}, @dvar{radix, 10}, @ovar{width})
+Expands to the value of @var{expression}.  The expansion is empty
+if an error is encountered while parsing the arguments.  If specified,
+@var{radix} and @var{width} control the format of the output.
+
+The macro @code{eval} is recognized only with parameters.
+@end deffn
+
+Expressions can contain the following operators, listed in order of
+decreasing precedence.
+
+@table @code
+@item + -
+Unary plus and minus
+@item **
+Exponentiation
+@item *  /  %
+Multiplication, division and modulo
+@item +  -
+Addition and subtraction
+@item <<  >>
+Shift left or right
+@item ==  !=  >  >=  <  <=
+Relational operators
+@item !
+Logical negation
+@item ~
+Bitwise negation
+@item &
+Bitwise and
+@item ^
+Bitwise exclusive-or
+@item |
+Bitwise or
+@item &&
+Logical and
+@item ||
+Logical or
+@end table
+
+All operators, except exponentiation, are left associative.
+
+Note that some older @code{m4} implementations use @samp{^} as an
+alternate operator for exponentiation, although @acronym{POSIX} requires
+the C behavior of bitwise exclusive-or.  On the other hand, the
+precedence of @samp{~} and @samp{!} are different in @acronym{GNU}
+@code{m4} than
+they are in C, matching the precedence in traditional @code{m4}
+implementations.  This behavior is likely to change in a future
+version to match @acronym{POSIX}, so use parentheses to force the
+desired precedence.
+
+Within @var{expression}, (but not @var{radix} or @var{width}),
+numbers without a special prefix are decimal.  A simple @samp{0}
+prefix introduces an octal number.  @samp{0x} introduces a hexadecimal
+number.  @samp{0b} introduces a binary number.  @samp{0r} introduces a
+number expressed in any radix between 1 and 36: the prefix should be
+immediately followed by the decimal expression of the radix, a colon,
+then the digits making the number.  For radix 1, leading zeros are
+ignored and all remaining digits must be @samp{1}; for all other
+radices, the digits are
+@samp{0}, @samp{1}, @samp{2}, @dots{}.  Beyond @samp{9}, the digits are
+@samp{a}, @samp{b} @dots{} up to @samp{z}.  Lower and upper case letters
+can be used interchangeably in numbers prefixes and as number digits.
+
+Parentheses may be used to group subexpressions whenever needed.  For the
+relational operators, a true relation returns @code{1}, and a false
+relation return @code{0}.
+
+Here are a few examples of use of @code{eval}.
+
+@example
+eval(`-3 * 5')
+@result{}-15
+eval(index(`Hello world', `llo') >= 0)
+@result{}1
+eval(`0r1:0111 + 0b100 + 0r3:12')
+@result{}12
+define(`square', `eval(`('$1`)**2')')
+@result{}
+square(`9')
+@result{}81
+square(square(`5')`+1')
+@result{}676
+define(`foo', `666')
+@result{}
+eval(`foo/6')
+@error{}m4:stdin:8: bad expression in eval: foo/6
+@result{}
+eval(foo/6)
+@result{}111
+@end example
+
+As the last two lines show, @code{eval} does not handle macro
+names, even if they expand to a valid expression (or part of a valid
+expression).  Therefore all macros must be expanded before they are
+passed to @code{eval}.
+
+All evaluation is done with 32-bit signed integers, assuming
+2's-complement with wrap-around.  The shift operators are defined in
+@acronym{GNU}
+@code{m4} by doing an implicit bit-wise and of the right-hand operand
+with 0x1f, and sign-extension with right shift.
+
+@example
+eval(0x80000000 / -1)
+@result{}-2147483648
+eval(0x80000000 % -1)
+@result{}0
+eval(0x7fffffff)
+@result{}2147483647
+incr(eval(0x7fffffff))
+@result{}-2147483648
+eval(-4 >> 33)
+@result{}-2
+@end example
+
+If @var{radix} is specified, it specifies the radix to be used in the
+expansion.  The default radix is 10; this is also the case if
+@var{radix} is the empty string.  It is an error if the radix is outside
+the range of 1 through 36, inclusive.  The result of @code{eval} is
+always taken to be signed.  No radix prefix is output, and for radices
+greater than 10, the digits are lower case.  The @var{width} argument
+specifies the minimum output width, excluding any negative sign.  The
+result is zero-padded to extend the expansion to the requested width.
+It is an error if the width is negative.  On error, the expansion of
+@code{eval} is empty.
+
+@example
+eval(`666', `10')
+@result{}666
+eval(`666', `11')
+@result{}556
+eval(`666', `6')
+@result{}3030
+eval(`666', `6', `10')
+@result{}0000003030
+eval(`-666', `6', `10')
+@result{}-0000003030
+eval(`10', `', `0')
+@result{}10
+`0r1:'eval(`10', `1', `11')
+@result{}0r1:01111111111
+eval(`10', `16')
+@result{}a
+@end example
+
+@node Shell commands
+@chapter Macros for running shell commands
+
+@cindex executing UNIX commands
+@cindex running UNIX commands
+@cindex UNIX commands, running
+@cindex commands, running UNIX
+@cindex executing shell commands
+@cindex running shell commands
+@cindex shell commands, running
+@cindex commands, running shell
+There are a few builtin macros in @code{m4} that allow you to run shell
+commands from within @code{m4}.
+
+Note that the definition of a valid shell command is system dependent.
+On UNIX systems, this is the typical @code{/bin/sh}.  But on other
+systems, such as native Windows, the shell has a different syntax of
+commands that it understands.  Some examples in this chapter assume
+@code{/bin/sh}, and also demonstrate how to quit early with a known
+exit value if this is not the case.
+
+@menu
+* Platform macros::             Determining the platform
+* Syscmd::                      Executing simple commands
+* Esyscmd::                     Reading the output of commands
+* Sysval::                      Exit status
+* Mkstemp::                     Making temporary files
+@end menu
+
+@node Platform macros
+@section Determining the platform
+
+@cindex platform macros
+Sometimes it is desirable for an input file to know which
+platform @code{m4} is running on.  @acronym{GNU} @code{m4} provides several
+macros that are predefined to expand to the empty string; checking for
+their existence will confirm platform details.
+
+@deffn {Optional builtin} __gnu__
+@deffnx {Optional builtin} __os2__
+@deffnx {Optional builtin} os2
+@deffnx {Optional builtin} __unix__
+@deffnx {Optional builtin} unix
+@deffnx {Optional builtin} __windows__
+@deffnx {Optional builtin} windows
+Each of these macros is conditionally defined as needed to describe the
+environment of @code{m4}.  If defined, each macro expands to the empty
+string.
+@end deffn
+
+When @acronym{GNU} extensions are in effect (that is, when you did not
+use the @option{-G} option, @pxref{Limits control, , Invoking m4}),
+@acronym{GNU} @code{m4} will define the macro @code{@w{__gnu__}} to
+expand to the empty string.
+
+@example
+__gnu__
+@result{}
+ifdef(`__gnu__', `Extensions are active')
+@result{}Extensions are active
+@end example
+
+@cindex platform macro
+On UNIX systems, @acronym{GNU} @code{m4} will define @code{@w{__unix__}}
+by default, or @code{unix} when the @option{-G} option is specified.
+
+On native Windows systems, @acronym{GNU} @code{m4} will define
+@code{@w{__windows__}} by default, or @code{windows} when the
+@option{-G} option is specified.
+
+On OS/2 systems, @acronym{GNU} @code{m4} will define @code{@w{__os2__}}
+by default, or @code{os2} when the @option{-G} option is specified.
+
+If @acronym{GNU} @code{m4} does not provide a platform macro for your system,
+please report that as a bug.
+
+@example
+define(`provided', `0')
+@result{}
+ifdef(`__unix__', `define(`provided', incr(provided))')
+@result{}
+ifdef(`__windows__', `define(`provided', incr(provided))')
+@result{}
+ifdef(`__os2__', `define(`provided', incr(provided))')
+@result{}
+provided
+@result{}1
+@end example
+
+@node Syscmd
+@section Executing simple commands
+
+Any shell command can be executed, using @code{syscmd}:
+
+@deffn Builtin syscmd (@var{shell-command})
+Executes @var{shell-command} as a shell command.
+
+The expansion of @code{syscmd} is void, @emph{not} the output from
+@var{shell-command}!  Output or error messages from @var{shell-command}
+are not read by @code{m4}.  @xref{Esyscmd}, if you need to process the
+command output.
+
+Prior to executing the command, @code{m4} flushes its buffers.
+The default standard input, output and error of @var{shell-command} are
+the same as those of @code{m4}.
+
+The macro @code{syscmd} is recognized only with parameters.
+@end deffn
+
+@example
+define(`foo', `FOO')
+@result{}
+syscmd(`echo foo')
+@result{}foo
+@result{}
+@end example
+
+Note how the expansion of @code{syscmd} keeps the trailing newline of
+the command, as well as using the newline that appeared after the macro.
+
+As an example of @var{shell-command} using the same standard input as
+@code{m4}, the command line @kbd{echo "m4wrap(\`syscmd(\`cat')')" | m4}
+will tell @code{m4} to read all of its input before executing the
+wrapped text, then hand a valid (albeit emptied) pipe as standard input
+for the @code{cat} subcommand.  Therefore, you should be careful when
+using standard input (either by specifying no files, or by passing
+@samp{-} as a file name on the command line, @pxref{Command line files,
+, Invoking m4}), and
+also invoking subcommands via @code{syscmd} or @code{esyscmd} that
+consume data from standard input.  When standard input is a seekable
+file, the subprocess will pick up with the next character not yet
+processed by @code{m4}; when it is a pipe or other non-seekable file,
+there is no guarantee how much data will already be buffered by
+@code{m4} and thus unavailable to the child.
+
+@ignore
+@comment If the user types the example below with stdin being an
+@comment interactive terminal, then cat will hang waiting for additional
+@comment input after m4 has exited.  But the testsuite is using a pipe
+@comment for stdin.  Hence, we have two versions - the one we feed the
+@comment testsuite below, and the one we display to the user above that
+@comment more accurately shows what the testsuite is really doing but
+@comment which the testsuite cannot parse.
+
+@example
+m4wrap(`syscmd(`cat')')
+@result{}
+^D
+@end example
+@end ignore
+
+@node Esyscmd
+@section Reading the output of commands
+
+@cindex @acronym{GNU} extensions
+If you want @code{m4} to read the output of a shell command, use
+@code{esyscmd}:
+
+@deffn Builtin esyscmd (@var{shell-command})
+Expands to the standard output of the shell command
+@var{shell-command}.
+
+Prior to executing the command, @code{m4} flushes its buffers.
+The default standard input and standard error of @var{shell-command} are
+the same as those of @code{m4}.  The error output of @var{shell-command}
+is not a part of the expansion: it will appear along with the error
+output of @code{m4}.
+
+The macro @code{esyscmd} is recognized only with parameters.
+@end deffn
+
+@example
+define(`foo', `FOO')
+@result{}
+esyscmd(`echo foo')
+@result{}FOO
+@result{}
+@end example
+
+Note how the expansion of @code{esyscmd} keeps the trailing newline of
+the command, as well as using the newline that appeared after the macro.
+
+Just as with @code{syscmd}, care must be exercised when sharing standard
+input between @code{m4} and the child process of @code{esyscmd}.
+
+@node Sysval
+@section Exit status
+
+@cindex UNIX commands, exit status from
+@cindex exit status from shell commands
+@cindex shell commands, exit status from
+@cindex commands, exit status from shell
+@cindex status of shell commands
+To see whether a shell command succeeded, use @code{sysval}:
+
+@deffn Builtin sysval
+Expands to the exit status of the last shell command run with
+@code{syscmd} or @code{esyscmd}.  Expands to 0 if no command has been
+run yet.
+@end deffn
+
+@example
+syscmd(`false')
+@result{}
+ifelse(sysval, `0', `zero', `non-zero')
+@result{}non-zero
+syscmd(`exit 2')
+@result{}
+sysval
+@result{}2
+syscmd(`true')
+@result{}
+sysval
+@result{}0
+esyscmd(`false')
+@result{}
+ifelse(sysval, `0', `zero', `non-zero')
+@result{}non-zero
+esyscmd(`exit 2')
+@result{}
+sysval
+@result{}2
+esyscmd(`true')
+@result{}
+sysval
+@result{}0
+@end example
+
+@command{sysval} results in 127 if there was a problem executing the
+command, for example, if the system-imposed argument length is exceeded,
+or if there were not enough resources to fork.  It is not possible to
+distinguish between failed execution and successful execution that had
+an exit status of 127.
+
+On UNIX platforms, where it is possible to detect when command execution
+is terminated by a signal, rather than a normal exit, the result is the
+signal number shifted left by eight bits.
+
+@comment This test has difficulties being portable, even on platforms
+@comment where syscmd invokes /bin/sh.  Kill is not portable with signal
+@comment names.  According to autoconf, the only portable signal numbers
+@comment are 1 (HUP), 2 (INT), 9 (KILL), 13 (PIPE) and 15 (TERM).  But
+@comment all shells handle SIGINT, and ksh handles HUP (as in, the shell
+@comment exits normally rather than letting the signal terminate it).
+@comment Also, TERM is flaky, as it can also kill the running m4 on
+@comment systems where /bin/sh does not create its own process group.
+@comment That leaves KILL and PIPE as the two signals tested.
+@example
+dnl This test assumes kill is a shell builtin, and that signals are
+dnl recognizable.
+ifdef(`__unix__', ,
+      `errprint(` skipping: syscmd does not have unix semantics
+')m4exit(`77')')dnl
+syscmd(`kill -13 $$')
+@result{}
+sysval
+@result{}3328
+esyscmd(`kill -9 $$')
+@result{}
+sysval
+@result{}2304
+@end example
+
+@node Mkstemp
+@section Making temporary files
+
+@cindex temporary file names
+@cindex files, names of temporary
+Commands specified to @code{syscmd} or @code{esyscmd} might need a
+temporary file, for output or for some other purpose.  There is a
+builtin macro, @code{mkstemp}, for making a temporary file:
+
+@deffn Builtin mkstemp (@var{template})
+@deffnx Builtin maketemp (@var{template})
+Expands to a name of a new, empty file, made from the string
+@var{template}, which should end with the string @samp{XXXXXX}.  The six
+@samp{X} characters are then replaced with random characters matching
+the regular expression @samp{[a-zA-Z0-9._-]}, in order to make the file
+name unique.  If fewer than six @samp{X} characters are found at the end
+of @code{template}, the result will be longer than the template.  The
+created file will have access permissions as if by @kbd{chmod =rw,go=},
+meaning that the current umask of the @code{m4} process is taken into
+account, and at most only the current user can read and write the file.
+
+The traditional behavior, standardized by @acronym{POSIX}, is that
+@code{maketemp} merely replaces the trailing @samp{X} with the process
+id, without creating a file, and without ensuring that the resulting
+string is a unique file name.  In part, this means that using the same
+@var{template} twice in the same input file will result in the same
+expansion.  This behavior is a security hole, as it is very easy for
+another process to guess the name that will be generated, and thus
+interfere with a subsequent use of @code{syscmd} trying to manipulate
+that file name.  Hence, @acronym{POSIX} has recommended that all new
+implementations of @code{m4} provide the secure @code{mkstemp} builtin,
+and that users of @code{m4} check for its existence.
+
+The macros @code{mkstemp} and @code{maketemp} are recognized only with
+parameters.
+@end deffn
+
+If you try this next example, you will most likely get different output
+for the two file names, since the replacement characters are randomly
+chosen:
+
+@comment ignore
+@example
+maketemp(`/tmp/fooXXXXXX')
+@result{}/tmp/fooa07346
+ifdef(`mkstemp', `define(`maketemp', defn(`mkstemp'))',
+      `define(`mkstemp', defn(`maketemp'))dnl
+errprint(`warning: potentially insecure maketemp implementation
+')')
+@result{}
+mkstemp(`doc')
+@result{}docQv83Uw
+@end example
+
+@cindex @acronym{GNU} extensions
+Unless you use the @option{--traditional} command line option (or
+@option{-G}, @pxref{Limits control, , Invoking m4}), the @acronym{GNU}
+version of @code{maketemp} is secure.  This means that using the same
+template to multiple calls will generate multiple files.  However, we
+recommend that you use the new @code{mkstemp} macro, introduced in
+@acronym{GNU} M4 1.4.8, which is secure even in traditional mode.
+
+@example
+syscmd(`echo foo??????')dnl
+@result{}foo??????
+define(`file1', maketemp(`fooXXXXXX'))dnl
+ifelse(esyscmd(`echo foo??????'), `foo??????', `no file', `created')
+@result{}created
+define(`file2', maketemp(`fooXX'))dnl
+define(`file3', mkstemp(`fooXXXXXX'))dnl
+ifelse(len(file1), len(file2), `same length', `different')
+@result{}same length
+ifelse(file1, file2, `same', `different file')
+@result{}different file
+ifelse(file2, file3, `same', `different file')
+@result{}different file
+ifelse(file1, file3, `same', `different file')
+@result{}different file
+syscmd(`rm 'file1 file2 file3)
+@result{}
+sysval
+@result{}0
+@end example
+
+@node Miscellaneous
+@chapter Miscellaneous builtin macros
+
+This chapter describes various builtins, that do not really belong in
+any of the previous chapters.
+
+@menu
+* Errprint::                    Printing error messages
+* Location::                    Printing current location
+* M4exit::                      Exiting from @code{m4}
+@end menu
+
+@node Errprint
+@section Printing error messages
+
+@cindex printing error messages
+@cindex error messages, printing
+@cindex messages, printing error
+You can print error messages using @code{errprint}:
+
+@deffn Builtin errprint (@var{message}, @dots{})
+Prints @var{message} and the rest of the arguments to standard error,
+separated by spaces.  Standard error is used, regardless of the
+@option{--debugfile} option (@pxref{Debugging options, , Invoking m4}).
+
+The expansion of @code{errprint} is void.
+The macro @code{errprint} is recognized only with parameters.
+@end deffn
+
+@example
+errprint(`Invalid arguments to forloop
+')
+@error{}Invalid arguments to forloop
+@result{}
+errprint(`1')errprint(`2',`3
+')
+@error{}12 3
+@result{}
+@end example
+
+A trailing newline is @emph{not} printed automatically, so it should be
+supplied as part of the argument, as in the example.  Unfortunately, the
+exact output of @code{errprint} is not very portable to other @code{m4}
+implementations: @acronym{POSIX} requires that all arguments be printed,
+but some implementations of @code{m4} only print the first.
+Furthermore, some BSD implementations always append a newline for each
+@code{errprint} call, regardless of whether the last argument already
+had one, and @acronym{POSIX} is silent on whether this is acceptable.
+
+@node Location
+@section Printing current location
+
+To make it possible to specify the location of an error, three
+utility builtins exist:
+
+@deffn Builtin __file__
+@deffnx Builtin __line__
+@deffnx Builtin __program__
+Expand to the quoted name of the current input file, the
+current input line number in that file, and the quoted name of the
+current invocation of @code{m4}.
+@end deffn
+
+@example
+errprint(__program__:__file__:__line__: `input error
+')
+@error{}m4:stdin:1: input error
+@result{}
+@end example
+
+Line numbers start at 1 for each file.  If the file was found due to the
+@option{-I} option or @env{M4PATH} environment variable, that is
+reflected in the file name.  The syncline option (@option{-s},
+@pxref{Preprocessor features, , Invoking m4}), and the
+@samp{f} and @samp{l} flags of @code{debugmode} (@pxref{Debug Levels}),
+also use this notion of current file and line.  Redefining the three
+location macros has no effect on syncline, debug, or warning message
+output.  Assume this example is run in the
+@file{m4-@value{VERSION}/@/checks} directory of the @acronym{GNU} M4
+package, using @samp{--include=../examples} in the command line to find
+the file @file{incl.m4} mentioned earlier:
+
+@example
+define(`foo', ``$0' called at __file__:__line__')
+@result{}
+foo
+@result{}foo called at stdin:2
+include(`incl.m4')
+@result{}Include file start
+@result{}foo called at ../examples/incl.m4:2
+@result{}Include file end
+@result{}
+@end example
+
+The location of macros invoked during the rescanning of macro expansion
+text corresponds to the location in the file where the expansion was
+triggered, regardless of how many newline characters the expansion text
+contains.  As of @acronym{GNU} M4 1.4.8, the location of text wrapped
+with @code{m4wrap} (@pxref{M4wrap}) is the point at which the
+@code{m4wrap} was invoked.  Previous versions, however, behaved as
+though wrapped text came from line 0 of the file ``''.
+
+@example
+define(`echo', `$@@')
+@result{}
+define(`foo', `echo(__line__
+__line__)')
+@result{}
+echo(__line__
+__line__)
+@result{}4
+@result{}5
+m4wrap(`foo
+')
+@result{}
+foo(errprint(__line__
+__line__
+))
+@error{}8
+@error{}9
+@result{}8
+@result{}8
+__line__
+@result{}11
+^D
+@result{}6
+@result{}6
+@end example
+
+The @code{@w{__program__}} macro behaves like @samp{$0} in shell
+terminology.  If you invoke @code{m4} through an absolute path or a link
+with a different spelling, rather than by relying on a @env{PATH} search
+for plain @samp{m4}, it will affect how @code{@w{__program__}} expands.
+The intent is that you can use it to produce error messages with the
+same formatting that @code{m4} produces internally.  It can also be used
+within @code{syscmd} (@pxref{Syscmd}) to pick the same version of
+@code{m4} that is currently running, rather than whatever version of
+@code{m4} happens to be first in @env{PATH}.  It was first introduced in
+@acronym{GNU} M4 1.4.6.
+
+@node M4exit
+@section Exiting from @code{m4}
+
+@cindex exiting from @code{m4}
+@cindex status, setting @code{m4} exit
+If you need to exit from @code{m4} before the entire input has been
+read, you can use @code{m4exit}:
+
+@deffn Builtin m4exit (@dvar{code, 0})
+Causes @code{m4} to exit, with exit status @var{code}.  If @var{code} is
+left out, the exit status is zero.  If @var{code} cannot be parsed, or
+is outside the range of 0 to 255, the exit status is one.  No further
+input is read, and all wrapped and diverted text is discarded.
+@end deffn
+
+@example
+m4wrap(`This text is lost due to `m4exit'.')
+@result{}
+divert(`1') So is this.
+divert
+@result{}
+m4exit And this is never read.
+@end example
+
+A common use of this is to abort processing:
+
+@deffn Composite fatal_error (@var{message})
+Abort processing with an error message and non-zero status.  Prefix
+@var{message} with details about where the error occurred, and print the
+resulting string to standard error.
+@end deffn
+
+@example
+define(`fatal_error',
+       `errprint(__program__:__file__:__line__`: fatal error: $*
+')m4exit(`1')')
+@result{}
+fatal_error(`this is a BAD one, buster')
+@error{}m4:stdin:4: fatal error: this is a BAD one, buster
+@end example
+
+After this macro call, @code{m4} will exit with exit status 1.  This macro
+is only intended for error exits, since the normal exit procedures are
+not followed, e.g., diverted text is not undiverted, and saved text
+(@pxref{M4wrap}) is not reread.  (This macro could be made more robust
+to earlier versions of @code{m4}.  You should try to see if you can find
+weaknesses and correct them; or @pxref{Improved fatal_error, , Answers}).
+
+Note that it is still possible for the exit status to be different than
+what was requested by @code{m4exit}.  If @code{m4} detects some other
+error, such as a write error on standard output, the exit status will be
+non-zero even if @code{m4exit} requested zero.
+
+If standard input is seekable, then the file will be positioned at the
+next unread character.  If it is a pipe or other non-seekable file,
+then there are no guarantees how much data @code{m4} might have read
+into buffers, and thus discarded.
+
+@node Frozen files
+@chapter Fast loading of frozen state
+
+Some bigger @code{m4} applications may be built over a common base
+containing hundreds of definitions and other costly initializations.
+Usually, the common base is kept in one or more declarative files,
+which files are listed on each @code{m4} invocation prior to the
+user's input file, or else each input file uses @code{include}.
+
+Reading the common base of a big application, over and over again, may
+be time consuming.  @acronym{GNU} @code{m4} offers some machinery to speed up
+the start of an application using lengthy common bases.
+
+@menu
+* Using frozen files::          Using frozen files
+* Frozen file format::          Frozen file format
+@end menu
+
+@node Using frozen files
+@section Using frozen files
+@cindex fast loading of frozen files
+@cindex frozen files for fast loading
+@cindex initialization, frozen states
+@cindex dumping into frozen file
+@cindex reloading a frozen file
+@cindex @acronym{GNU} extensions
+Suppose a user has a library of @code{m4} initializations in
+@file{base.m4}, which is then used with multiple input files:
+
+@comment ignore
+@example
+m4 base.m4 input1.m4
+m4 base.m4 input2.m4
+m4 base.m4 input3.m4
+@end example
+
+Rather than spending time parsing the fixed contents of @file{base.m4}
+every time, the user might rather execute:
+
+@comment ignore
+@example
+m4 -F base.m4f base.m4
+@end example
+
+@noindent
+once, and further execute, as often as needed:
+
+@comment ignore
+@example
+m4 -R base.m4f input1.m4
+m4 -R base.m4f input2.m4
+m4 -R base.m4f input3.m4
+@end example
+
+@noindent
+with the varying input.  The first call, containing the @option{-F}
+option, only reads and executes file @file{base.m4}, defining
+various application macros and computing other initializations.
+Once the input file @file{base.m4} has been completely processed, @acronym{GNU}
+@code{m4} produces on @file{base.m4f} a @dfn{frozen} file, that is, a
+file which contains a kind of snapshot of the @code{m4} internal state.
+
+Later calls, containing the @option{-R} option, are able to reload
+the internal state of @code{m4}, from @file{base.m4f},
+@emph{prior} to reading any other input files.  This means
+instead of starting with a virgin copy of @code{m4}, input will be
+read after having effectively recovered the effect of a prior run.
+In our example, the effect is the same as if file @file{base.m4} has
+been read anew.  However, this effect is achieved a lot faster.
+
+Only one frozen file may be created or read in any one @code{m4}
+invocation.  It is not possible to recover two frozen files at once.
+However, frozen files may be updated incrementally, through using
+@option{-R} and @option{-F} options simultaneously.  For example, if
+some care is taken, the command:
+
+@comment ignore
+@example
+m4 file1.m4 file2.m4 file3.m4 file4.m4
+@end example
+
+@noindent
+could be broken down in the following sequence, accumulating the same
+output:
+
+@comment ignore
+@example
+m4 -F file1.m4f file1.m4
+m4 -R file1.m4f -F file2.m4f file2.m4
+m4 -R file2.m4f -F file3.m4f file3.m4
+m4 -R file3.m4f file4.m4
+@end example
+
+Some care is necessary because not every effort has been made for
+this to work in all cases.  In particular, the trace attribute of
+macros is not handled, nor the current setting of @code{changeword}.
+Currently, @code{m4wrap} and @code{sysval} also have problems.
+Also, interactions for some options of @code{m4}, being used in one call
+and not in the next, have not been fully analyzed yet.  On the other
+end, you may be confident that stacks of @code{pushdef} definitions
+are handled correctly, as well as undefined or renamed builtins, and
+changed strings for quotes or comments.  And future releases of
+@acronym{GNU} M4 will improve on the utility of frozen files.
+
+When an @code{m4} run is to be frozen, the automatic undiversion
+which takes place at end of execution is inhibited.  Instead, all
+positively numbered diversions are saved into the frozen file.
+The active diversion number is also transmitted.
+
+A frozen file to be reloaded need not reside in the current directory.
+It is looked up the same way as an @code{include} file (@pxref{Search
+Path}).
+
+If the frozen file was generated with a newer version of @code{m4}, and
+contains directives that an older @code{m4} cannot parse, attempting to
+load the frozen file with option @option{-R} will cause @code{m4} to
+exit with status 63 to indicate version mismatch.
+
+@node Frozen file format
+@section Frozen file format
+@cindex frozen file format
+@cindex file format, frozen file
+Frozen files are sharable across architectures.  It is safe to write
+a frozen file on one machine and read it on another, given that the
+second machine uses the same or newer version of @acronym{GNU} @code{m4}.
+It is conventional, but not required, to give a frozen file the suffix
+of @code{.m4f}.
+
+These are simple (editable) text files, made up of directives,
+each starting with a capital letter and ending with a newline
+(@key{NL}).  Wherever a directive is expected, the character
+@samp{#} introduces a comment line; empty lines are also ignored if they
+are not part of an embedded string.
+In the following descriptions, each @var{len} refers to the length of
+the corresponding strings @var{str} in the next line of input.  Numbers
+are always expressed in decimal.  There are no escape characters.  The
+directives are:
+
+@table @code
+@item C @var{len1} , @var{len2} @key{NL} @var{str1} @var{str2} @key{NL}
+Uses @var{str1} and @var{str2} as the begin-comment and
+end-comment strings.  If omitted, then @samp{#} and @key{NL} are the
+comment delimiters.
+
+@item D @var{number}, @var{len} @key{NL} @var{str} @key{NL}
+Selects diversion @var{number}, making it current, then copy
+@var{str} in the current diversion.  @var{number} may be a negative
+number for a non-existing diversion.  To merely specify an active
+selection, use this command with an empty @var{str}.  With 0 as the
+diversion @var{number}, @var{str} will be issued on standard output
+at reload time.  @acronym{GNU} @code{m4} will not produce the @samp{D}
+directive with non-zero length for diversion 0, but this can be done
+with manual edits.  This directive may
+appear more than once for the same diversion, in which case the
+diversion is the concatenation of the various uses.  If omitted, then
+diversion 0 is current.
+
+@item F @var{len1} , @var{len2} @key{NL} @var{str1} @var{str2} @key{NL}
+Defines, through @code{pushdef}, a definition for @var{str1}
+expanding to the function whose builtin name is @var{str2}.  If the
+builtin does not exist (for example, if the frozen file was produced by
+a copy of @code{m4} compiled with changeword support, but the version
+of @code{m4} reloading was compiled without it), the reload is silent,
+but any subsequent use of the definition of @var{str1} will result in
+a warning.  This directive may appear more than once for the same name,
+and its order, along with @samp{T}, is important.  If omitted, you will
+have no access to any builtins.
+
+@item Q @var{len1} , @var{len2} @key{NL} @var{str1} @var{str2} @key{NL}
+Uses @var{str1} and @var{str2} as the begin-quote and end-quote
+strings.  If omitted, then @samp{`} and @samp{'} are the quote
+delimiters.
+
+@item T @var{len1} , @var{len2} @key{NL} @var{str1} @var{str2} @key{NL}
+Defines, though @code{pushdef}, a definition for @var{str1}
+expanding to the text given by @var{str2}.  This directive may appear
+more than once for the same name, and its order, along with @samp{F}, is
+important.
+
+@item V @var{number} @key{NL}
+Confirms the format of the file.  @code{m4} @value{VERSION} only creates
+and understands frozen files where @var{number} is 1.  This directive
+must be the first non-comment in the file, and may not appear more than
+once.
+@end table
+
+@node Compatibility
+@chapter Compatibility with other versions of @code{m4}
+
+@cindex compatibility
+This chapter describes the differences between this implementation of
+@code{m4}, and the implementation found under UNIX, notably System V,
+Release 3.
+
+There are also differences in BSD flavors of @code{m4}.  No attempt
+is made to summarize these here.
+
+@menu
+* Extensions::                  Extensions in @acronym{GNU} M4
+* Incompatibilities::           Facilities in System V m4 not in GNU M4
+* Other Incompatibilities::     Other incompatibilities
+@end menu
+
+@node Extensions
+@section Extensions in @acronym{GNU} @code{m4}
+
+@cindex @acronym{GNU} extensions
+This version of @code{m4} contains a few facilities that do not exist
+in System V @code{m4}.  These extra facilities are all suppressed by
+using the @option{-G} command line option (@pxref{Limits control, ,
+Invoking m4}), unless overridden by other command line options.
+
+@itemize @bullet
+@item
+In the @code{$}@var{n} notation for macro arguments, @var{n} can contain
+several digits, while the System V @code{m4} only accepts one digit.
+This allows macros in @acronym{GNU} @code{m4} to take any number of
+arguments, and not only nine (@pxref{Arguments}).
+
+This means that @code{define(`foo', `$11')} is ambiguous between
+implementations.  To portably choose between grabbing the first
+parameter and appending 1 to the expansion, or grabbing the eleventh
+parameter, you can do the following:
+
+@example
+define(`a1', `A1')
+@result{}
+dnl First argument, concatenated with 1
+define(`_1', `$1')define(`first1', `_1($@@)1')
+@result{}
+dnl Eleventh argument, portable
+define(`_9', `$9')define(`eleventh', `_9(shift(shift($@@)))')
+@result{}
+dnl Eleventh argument, GNU style
+define(`Eleventh', `$11')
+@result{}
+first1(`a', `b', `c', `d', `e', `f', `g', `h', `i', `j', `k')
+@result{}A1
+eleventh(`a', `b', `c', `d', `e', `f', `g', `h', `i', `j', `k')
+@result{}k
+Eleventh(`a', `b', `c', `d', `e', `f', `g', `h', `i', `j', `k')
+@result{}k
+@end example
+
+@item
+The @code{divert} (@pxref{Divert}) macro can manage more than 9
+diversions.  @acronym{GNU} @code{m4} treats all positive numbers as valid
+diversions, rather than discarding diversions greater than 9.
+
+@item
+Files included with @code{include} and @code{sinclude} are sought in a
+user specified search path, if they are not found in the working
+directory.  The search path is specified by the @option{-I} option and the
+@env{M4PATH} environment variable (@pxref{Search Path}).
+
+@item
+Arguments to @code{undivert} can be non-numeric, in which case the named
+file will be included uninterpreted in the output (@pxref{Undivert}).
+
+@item
+Formatted output is supported through the @code{format} builtin, which
+is modeled after the C library function @code{printf} (@pxref{Format}).
+
+@item
+Searches and text substitution through regular expressions are
+supported by the @code{regexp} (@pxref{Regexp}) and @code{patsubst}
+(@pxref{Patsubst}) builtins.
+
+@item
+The output of shell commands can be read into @code{m4} with
+@code{esyscmd} (@pxref{Esyscmd}).
+
+@item
+There is indirect access to any builtin macro with @code{builtin}
+(@pxref{Builtin}).
+
+@item
+Macros can be called indirectly through @code{indir} (@pxref{Indir}).
+
+@item
+The name of the program, the current input file, and the current input
+line number are accessible through the builtins @code{@w{__program__}},
+@code{@w{__file__}}, and @code{@w{__line__}} (@pxref{Location}).
+
+@item
+The format of the output from @code{dumpdef} and macro tracing can be
+controlled with @code{debugmode} (@pxref{Debug Levels}).
+
+@item
+The destination of trace and debug output can be controlled with
+@code{debugfile} (@pxref{Debug Output}).
+
+@item
+The @code{maketemp} (@pxref{Mkstemp}) macro behaves like @code{mkstemp},
+creating a new file with a unique name on every invocation, rather than
+following the insecure behavior of replacing the trailing @samp{X}
+characters with the @code{m4} process id.
+@end itemize
+
+In addition to the above extensions, @acronym{GNU} @code{m4} implements the
+following command line options: @option{-F}, @option{-G}, @option{-I},
+@option{-L}, @option{-R}, @option{-V}, @option{-W}, @option{-d}, @option{-i},
+@option{-l}, @option{--debugfile} and @option{-t}.  @xref{Invoking m4}, for a
+description of these options.
+
+Also, the debugging and tracing facilities in @acronym{GNU} @code{m4} are much
+more extensive than in most other versions of @code{m4}.
+
+@node Incompatibilities
+@section Facilities in System V @code{m4} not in @acronym{GNU} @code{m4}
+
+The version of @code{m4} from System V contains a few facilities that
+have not been implemented in @acronym{GNU} @code{m4} yet.  Additionally,
+@acronym{POSIX} requires some behaviors that @acronym{GNU} @code{m4} has not
+implemented yet.  Relying on these behaviors is non-portable, as a
+future release of @acronym{GNU} @code{m4} may change.
+
+@itemize @bullet
+@item
+System V @code{m4} supports multiple arguments to @code{defn}, and
+@acronym{POSIX} requires it.  This is not yet implemented in @acronym{GNU}
+@code{m4}.  Unfortunately, this means it is not possible to mix builtins
+and other text into a single macro; a helper macro is required.
+
+@item
+@acronym{POSIX} requires an application to exit with non-zero status if
+it wrote an error message to stderr.  This has not yet been consistently
+implemented for the various builtins that are required to issue an error
+(such as @code{include} (@pxref{Include}) when a file is unreadable,
+@code{eval} (@pxref{Eval}) when an argument cannot be parsed, or using
+@code{m4exit} (@pxref{M4exit}) with a non-numeric argument).
+
+@item
+Some traditional implementations only allow reading standard input
+once, but @acronym{GNU} @code{m4} correctly handles multiple instances
+of @samp{-} on the command line.
+
+@item
+@acronym{POSIX} requires @code{m4wrap} (@pxref{M4wrap}) to act in FIFO
+(first-in, first-out) order, but @acronym{GNU} @code{m4} currently uses
+LIFO order.  Furthermore, @acronym{POSIX} states that only the first
+argument to @code{m4wrap} is saved for later evaluation, bug
+@acronym{GNU} @code{m4} saves and processes all arguments, with output
+separated by spaces.
+
+However, it is possible to emulate @acronym{POSIX} behavior by
+including the file @file{m4-@value{VERSION}/@/examples/@/wrapfifo.m4}
+from the distribution:
+
+@example
+undivert(`wrapfifo.m4')dnl
+@result{}dnl Redefine m4wrap to have FIFO semantics.
+@result{}define(`_m4wrap_level', `0')dnl
+@result{}define(`m4wrap',
+@result{}`ifdef(`m4wrap'_m4wrap_level,
+@result{}       `define(`m4wrap'_m4wrap_level,
+@result{}               defn(`m4wrap'_m4wrap_level)`$1')',
+@result{}       `builtin(`m4wrap', `define(`_m4wrap_level',
+@result{}                                  incr(_m4wrap_level))dnl
+@result{}m4wrap'_m4wrap_level)dnl
+@result{}define(`m4wrap'_m4wrap_level, `$1')')')dnl
+include(`wrapfifo.m4')
+@result{}
+m4wrap(`a`'m4wrap(`c
+', `d')')m4wrap(`b')
+@result{}
+^D
+@result{}abc
+@end example
+
+@item
+@acronym{POSIX} requires that all builtins that require arguments, but
+are called without arguments, behave as though empty strings had been
+passed.  For example, @code{a`'define`'b} would expand to @code{ab}.
+But @acronym{GNU} @code{m4} ignores certain builtins if they have missing
+arguments, giving @code{adefineb} for the above example.
+
+@item
+Traditional implementations handle @code{define(`f',`1')} (@pxref{Define})
+by undefining the entire stack of previous definitions, and if doing
+@code{undefine(`f')} first.  @acronym{GNU} @code{m4} replaces just the top
+definition on the stack, as if doing @code{popdef(`f')} followed by
+@code{pushdef(`f',`1')}.
+
+@item
+@acronym{POSIX} requires @code{syscmd} (@pxref{Syscmd}) to evaluate
+command output for macro expansion, but this appears to be a mistake
+in @acronym{POSIX} since traditional implementations did not do this.
+@acronym{GNU} @code{m4} follows traditional behavior in @code{syscmd}, and
+provides the extension @code{esyscmd} that provides the @acronym{POSIX}
+semantics.
+
+@item
+At one point, @acronym{POSIX} required @code{changequote(@var{arg})}
+(@pxref{Changequote}) to use newline as the close quote, but this was a
+bug, and the next version of @acronym{POSIX} is anticipated to state
+that using empty strings or just one argument is unspecified.
+Meanwhile, the @acronym{GNU} @code{m4} behavior of treating an empty
+end-quote delimiter as @samp{'} is not portable, as Solaris treats it as
+repeating the start-quote delimiter, and BSD treats it as leaving the
+previous end-quote delimiter unchanged.  For predictable results, never
+call changequote with just one argument, or with empty strings for
+arguments.
+
+@item
+At one point, @acronym{POSIX} required @code{changecom(@var{arg},)}
+(@pxref{Changecom}) to make it impossible to end a comment, but this is
+a bug, and the next version of @acronym{POSIX} is anticipated to state
+that using empty strings is unspecified.  Meanwhile, the @acronym{GNU}
+@code{m4} behavior of treating an empty end-comment delimiter as newline
+is not portable, as BSD treats it as leaving the previous end-comment
+delimiter unchanged.  It is also impossible in BSD implementations to
+disable comments, even though that is required by @acronym{POSIX}.  For
+predictable results, never call changecom with empty strings for
+arguments.
+
+@item
+Most implementations of @code{m4} give macros a higher precedence than
+comments when parsing, meaning that if the start delimiter given to
+@code{changecom} (@pxref{Changecom}) starts with a macro name, comments
+are effectively disabled.  @acronym{POSIX} does not specify what the
+precedence is, so the @acronym{GNU} @code{m4} parser recognizes
+comments, then macros, then quoted strings.
+
+@item
+Traditional implementations allow argument collection, but not string
+and comment processing, to span file boundaries.  Thus, if @file{a.m4}
+contains @samp{len(}, and @file{b.m4} contains @samp{abc)},
+@kbd{m4 a.m4 b.m4} outputs @samp{3} with traditional @code{m4}, but
+gives an error message that the end of file was encountered inside a
+macro with @acronym{GNU} @code{m4}.  On the other hand, traditional
+implementations do end of file processing for files included with
+@code{include} or @code{sinclude} (@pxref{Include}), while @acronym{GNU}
+@code{m4} seamlessly integrates the content of those files.  Thus
+@code{include(`a.m4')include(`b.m4')} will output @samp{3} instead of
+giving an error.
+
+@item
+Traditional @code{m4} treats @code{traceon} (@pxref{Trace}) without
+arguments as a global variable, independent of named macro tracing.
+Also, once a macro is undefined, named tracing of that macro is lost.
+On the other hand, when @acronym{GNU} @code{m4} encounters
+@code{traceon} without
+arguments, it turns tracing on for all existing definitions at the time,
+but does not trace future definitions; @code{traceoff} without arguments
+turns tracing off for all definitions regardless of whether they were
+also traced by name; and tracing by name, such as with @option{-tfoo} at
+the command line or @code{traceon(`foo')} in the input, is an attribute
+that is preserved even if the macro is currently undefined.
+
+@item
+@acronym{POSIX} requires @code{eval} (@pxref{Eval}) to treat all
+operators with the same precedence as C.  However, @acronym{GNU} @code{m4}
+currently follows the traditional precedence of other @code{m4}
+implementations, where bitwise and logical negation (@samp{~} and
+@samp{!}) have lower precedence than equality operators, rather than
+equal precedence with other unary operators.  Use explicit parentheses
+to ensure proper precedence.  As extensions to @acronym{POSIX}, @acronym{GNU}
+@code{m4} treats the shift operators @samp{<<} and @samp{>>} as
+well-defined on signed integers (even though they are not in C), and
+adds the exponentiation operator @samp{**}.
+
+@item
+@acronym{POSIX} requires @code{translit} (@pxref{Translit}) to treat
+each character of the second and third arguments literally, but @acronym{GNU}
+@code{m4} treats @samp{-} as a range operator.
+
+@item
+@acronym{POSIX} requires @code{m4} to honor the locale environment
+variables of @env{LANG}, @env{LC_ALL}, @env{LC_CTYPE},
+@env{LC_MESSAGES}, and @env{NLSPATH}, but this has not yet been
+implemented in @acronym{GNU} @code{m4}.
+
+@item
+@acronym{POSIX} states that only unquoted leading newlines and blanks
+(that is, space and tab) are ignored when collecting macro arguments.
+However, this appears to be a bug in @acronym{POSIX}, since most
+traditional implementations also ignore all whitespace (formfeed,
+carriage return, and vertical tab).  @acronym{GNU} @code{m4} follows
+tradition and ignores all leading unquoted whitespace.
+@end itemize
+
+@node Other Incompatibilities
+@section Other incompatibilities
+
+There are a few other incompatibilities between this implementation of
+@code{m4}, and the System V version.
+
+@itemize @bullet
+@item
+@acronym{GNU} @code{m4} implements sync lines differently from System V
+@code{m4}, when text is being diverted.  @acronym{GNU} @code{m4} outputs
+the sync lines when the text is being diverted, and System V @code{m4}
+when the diverted text is being brought back.
+
+The problem is which lines and file names should be attached to text that
+is being, or has been, diverted.  System V @code{m4} regards all the
+diverted text as being generated by the source line containing the
+@code{undivert} call, whereas @acronym{GNU} @code{m4} regards the
+diverted text as being generated at the time it is diverted.
+
+The sync line option is used mostly when using @code{m4} as
+a front end to a compiler.  If a diverted line causes a compiler error,
+the error messages should most probably refer to the place where the
+diversion were made, and not where it was inserted again.
+
+@item
+@acronym{GNU} @code{m4} makes no attempt at prohibiting self-referential
+definitions like:
+
+@comment ignore
+@example
+define(`x', `x')
+@result{}
+define(`x', `x ')
+@result{}
+@end example
+
+There is nothing inherently wrong with defining @samp{x} to
+return @samp{x}.  The wrong thing is to expand @samp{x} unquoted.
+In @code{m4}, one might use macros to hold strings, as we do for
+variables in other programming languages, further checking them with:
+
+@comment ignore
+@example
+ifelse(defn(`@var{holder}'), `@var{value}', @dots{})
+@end example
+
+@noindent
+In cases like this one, an interdiction for a macro to hold its own
+name would be a useless limitation.  Of course, this leaves more rope
+for the @acronym{GNU} @code{m4} user to hang himself!  Rescanning hangs may be
+avoided through careful programming, a little like for endless loops
+in traditional programming languages.
+@end itemize
+
+@node Answers
+@chapter Correct version of some examples
+
+Some of the examples in this manuals are buggy or not very robust, for
+demonstration purposes.  Improved versions of these composite macros are
+presented here.
+
+@menu
+* Improved exch::               Solution for @code{exch}
+* Improved forloop::            Solution for @code{forloop}
+* Improved foreach::            Solution for @code{foreach}
+* Improved cleardivert::        Solution for @code{cleardivert}
+* Improved fatal_error::        Solution for @code{fatal_error}
+@end menu
+
+@node Improved exch
+@section Solution for @code{exch}
+
+The @code{exch} macro (@pxref{Arguments}) as presented requires clients
+to double quote their arguments.  A nicer definition, which lets
+clients follow the rule of thumb of one level of quoting per level of
+parentheses, involves adding quotes in the definition of @code{exch}, as
+follows:
+
+@example
+define(`exch', ``$2', `$1'')
+@result{}
+define(exch(`expansion text', `macro'))
+@result{}
+macro
+@result{}expansion text
+@end example
+
+@node Improved forloop
+@section Solution for @code{forloop}
+
+The @code{forloop} macro (@pxref{Forloop}) as presented earlier can go
+into an infinite loop if given an iterator that is not parsed as a macro
+name.  It does not do any sanity checking on its numeric bounds, and
+only permits decimal numbers for bounds.  Here is an improved version,
+shipped as @file{m4-@value{VERSION}/@/examples/@/forloop2.m4}; this
+version also optimizes based on the fact that the starting bound does
+not need to be passed to the helper @code{@w{_forloop}}.
+
+@example
+undivert(`forloop2.m4')dnl
+@result{}divert(`-1')
+@result{}# forloop(var, from, to, stmt) - improved version:
+@result{}#   works even if VAR is not a strict macro name
+@result{}#   performs sanity check that FROM is larger than TO
+@result{}#   allows complex numerical expressions in TO and FROM
+@result{}define(`forloop', `ifelse(eval(`($3) >= ($2)'), `1',
+@result{}  `pushdef(`$1', eval(`$2'))_forloop(`$1',
+@result{}    eval(`$3'), `$4')popdef(`$1')')')
+@result{}define(`_forloop',
+@result{}  `$3`'ifelse(indir(`$1'), `$2', `',
+@result{}    `define(`$1', incr(indir(`$1')))$0($@@)')')
+@result{}divert`'dnl
+include(`forloop2.m4')
+@result{}
+forloop(`i', `2', `1', `no iteration occurs')
+@result{}
+forloop(`', `1', `2', ` odd iterator name')
+@result{} odd iterator name odd iterator name
+forloop(`i', `5 + 5', `0xc', ` 0x`'eval(i, `16')')
+@result{} 0xa 0xb 0xc
+forloop(`i', `a', `b', `non-numeric bounds')
+@error{}m4:stdin:6: bad expression in eval (bad input): (b) >= (a)
+@result{}
+@end example
+
+Of course, it is possible to make even more improvements, such as
+adding an optional step argument, or allowing iteration through
+descending sequences.  @acronym{GNU} Autoconf provides some of these
+additional bells and whistles in its @code{m4_for} macro.
+
+@node Improved foreach
+@section Solution for @code{foreach}
+
+The @code{foreach} and @code{foreachq} macros (@pxref{Foreach}) as
+presented earlier each have flaws.  First, we will examine and fix the
+quadratic behavior of @code{foreachq}:
+
+@example
+include(`foreachq.m4')
+@result{}
+traceon(`shift')debugmode(`aq')
+@result{}
+foreachq(`x', ``1', `2', `3', `4'', `x
+')dnl
+@result{}1
+@error{}m4trace: -3- shift(`1', `2', `3', `4')
+@error{}m4trace: -2- shift(`1', `2', `3', `4')
+@result{}2
+@error{}m4trace: -4- shift(`1', `2', `3', `4')
+@error{}m4trace: -3- shift(`2', `3', `4')
+@error{}m4trace: -3- shift(`1', `2', `3', `4')
+@error{}m4trace: -2- shift(`2', `3', `4')
+@result{}3
+@error{}m4trace: -5- shift(`1', `2', `3', `4')
+@error{}m4trace: -4- shift(`2', `3', `4')
+@error{}m4trace: -3- shift(`3', `4')
+@error{}m4trace: -4- shift(`1', `2', `3', `4')
+@error{}m4trace: -3- shift(`2', `3', `4')
+@error{}m4trace: -2- shift(`3', `4')
+@result{}4
+@error{}m4trace: -6- shift(`1', `2', `3', `4')
+@error{}m4trace: -5- shift(`2', `3', `4')
+@error{}m4trace: -4- shift(`3', `4')
+@error{}m4trace: -3- shift(`4')
+@end example
+
+Each successive iteration was adding more quoted @code{shift}
+invocations, and the entire list contents were passing through every
+iteration.  In general, when recursing, it is a good idea to make the
+recursion use fewer arguments, rather than adding additional quoted
+uses of @code{shift}.  By doing so, @code{m4} uses less memory, invokes
+fewer macros, is less likely to run into machine limits, and most
+importantly, performs faster.  The fixed version of @code{foreachq} can
+be found in @file{m4-@value{VERSION}/@/examples/@/foreachq2.m4}:
+
+@example
+include(`foreachq2.m4')
+@result{}
+undivert(`foreachq2.m4')dnl
+@result{}include(`quote.m4')dnl
+@result{}divert(`-1')
+@result{}# foreachq(x, `item_1, item_2, ..., item_n', stmt)
+@result{}#   quoted list, improved version
+@result{}define(`foreachq', `pushdef(`$1')_foreachq($@@)popdef(`$1')')
+@result{}define(`_arg1q', ``$1'')
+@result{}define(`_rest', `ifelse(`$#', `1', `', `dquote(shift($@@))')')
+@result{}define(`_foreachq', `ifelse(`$2', `', `',
+@result{}  `define(`$1', _arg1q($2))$3`'$0(`$1', _rest($2), `$3')')')
+@result{}divert`'dnl
+traceon(`shift')debugmode(`aq')
+@result{}
+foreachq(`x', ``1', `2', `3', `4'', `x
+')dnl
+@result{}1
+@error{}m4trace: -3- shift(`1', `2', `3', `4')
+@result{}2
+@error{}m4trace: -3- shift(`2', `3', `4')
+@result{}3
+@error{}m4trace: -3- shift(`3', `4')
+@result{}4
+@end example
+
+Note that the fixed version calls unquoted helper macros in
+@code{@w{_foreachq}} to trim elements immediately; those helper macros
+in turn must re-supply the layer of quotes lost in the macro invocation.
+Contrast the use of @code{@w{_arg1q}}, which quotes the first list
+element, with @code{@w{_arg1}} of the earlier implementation that
+returned the first list element directly.
+
+For a different approach, the improved version of @code{foreach},
+available in @file{m4-@value{VERSION}/@/examples/@/foreach2.m4}, simply
+overquotes the arguments to @code{@w{_foreach}} to begin with, using
+@code{dquote_elt}.  Then @code{@w{_foreach}} can just use
+@code{@w{_arg1}} to remove the extra layer of quoting that was added up
+front:
+
+@example
+include(`foreach2.m4')
+@result{}
+undivert(`foreach2.m4')dnl
+@result{}include(`quote.m4')dnl
+@result{}divert(`-1')
+@result{}# foreach(x, (item_1, item_2, ..., item_n), stmt)
+@result{}#   parenthesized list, improved version
+@result{}define(`foreach', `pushdef(`$1')_foreach(`$1',
+@result{}  (dquote(dquote_elt$2)), `$3')popdef(`$1')')
+@result{}define(`_arg1', `$1')
+@result{}define(`_foreach', `ifelse(`$2', `(`')', `',
+@result{}  `define(`$1', _arg1$2)$3`'$0(`$1', (dquote(shift$2)), `$3')')')
+@result{}divert`'dnl
+traceon(`shift')debugmode(`aq')
+@result{}
+foreach(`x', `(`1', `2', `3', `4')', `x
+')dnl
+@error{}m4trace: -4- shift(`1', `2', `3', `4')
+@error{}m4trace: -4- shift(`2', `3', `4')
+@error{}m4trace: -4- shift(`3', `4')
+@result{}1
+@error{}m4trace: -3- shift(``1'', ``2'', ``3'', ``4'')
+@result{}2
+@error{}m4trace: -3- shift(``2'', ``3'', ``4'')
+@result{}3
+@error{}m4trace: -3- shift(``3'', ``4'')
+@result{}4
+@error{}m4trace: -3- shift(``4'')
+@end example
+
+In summary, recursion over list elements is trickier than it appeared at
+first glance, but provides a powerful idiom within @code{m4} processing.
+As a final demonstration, both list styles are now able to handle
+several scenarios that would wreak havoc on the original
+implementations.  This points out one other difference between the two
+list styles.  @code{foreach} evaluates unquoted list elements only once,
+in preparation for calling @code{@w{_foreach}}.  But @code{foreachq}
+evaluates unquoted list elements twice while visiting the first list
+element, once in @code{@w{_arg1q}} and once in @code{@w{_rest}}.  When
+deciding which list style to use, one must take into account whether
+repeating the side effects of unquoted list elements will have any
+detrimental effects.
+
+@example
+include(`foreach2.m4')
+@result{}
+include(`foreachq2.m4')
+@result{}
+dnl 0-element list:
+foreach(`x', `', `<x>') / foreachq(`x', `', `<x>')
+@result{} /@w{ }
+dnl 1-element list of empty element
+foreach(`x', `()', `<x>') / foreachq(`x', ``'', `<x>')
+@result{}<> / <>
+dnl 2-element list of empty elements
+foreach(`x', `(`',`')', `<x>') / foreachq(`x', ``',`'', `<x>')
+@result{}<><> / <><>
+dnl 1-element list of a comma
+foreach(`x', `(`,')', `<x>') / foreachq(`x', ``,'', `<x>')
+@result{}<,> / <,>
+dnl 2-element list of unbalanced parentheses
+foreach(`x', `(`(', `)')', `<x>') / foreachq(`x', ``(', `)'', `<x>')
+@result{}<(><)> / <(><)>
+define(`active', `ACT, IVE')
+@result{}
+traceon(`active')
+@result{}
+dnl list of unquoted macros; expansion occurs before recursion
+foreach(`x', `(active, active)', `<x>
+')dnl
+@error{}m4trace: -4- active -> `ACT, IVE'
+@error{}m4trace: -4- active -> `ACT, IVE'
+@result{}<ACT>
+@result{}<IVE>
+@result{}<ACT>
+@result{}<IVE>
+foreachq(`x', `active, active', `<x>
+')dnl
+@error{}m4trace: -3- active -> `ACT, IVE'
+@error{}m4trace: -3- active -> `ACT, IVE'
+@result{}<ACT>
+@error{}m4trace: -3- active -> `ACT, IVE'
+@error{}m4trace: -3- active -> `ACT, IVE'
+@result{}<IVE>
+@result{}<ACT>
+@result{}<IVE>
+dnl list of quoted macros; expansion occurs during recursion
+foreach(`x', `(`active', `active')', `<x>
+')dnl
+@error{}m4trace: -1- active -> `ACT, IVE'
+@result{}<ACT, IVE>
+@error{}m4trace: -1- active -> `ACT, IVE'
+@result{}<ACT, IVE>
+foreachq(`x', ``active', `active'', `<x>
+')dnl
+@error{}m4trace: -1- active -> `ACT, IVE'
+@result{}<ACT, IVE>
+@error{}m4trace: -1- active -> `ACT, IVE'
+@result{}<ACT, IVE>
+dnl list of double-quoted macro names; no expansion
+foreach(`x', `(``active'', ``active'')', `<x>
+')dnl
+@result{}<active>
+@result{}<active>
+foreachq(`x', ```active'', ``active''', `<x>
+')dnl
+@result{}<active>
+@result{}<active>
+@end example
+
+@node Improved cleardivert
+@section Solution for @code{cleardivert}
+
+The @code{cleardivert} macro (@pxref{Cleardivert}) cannot, as it stands, be
+called without arguments to clear all pending diversions.  That is
+because using undivert with an empty string for an argument is different
+than using it with no arguments at all.  Compare the earlier definition
+with one that takes the number of arguments into account:
+
+@example
+define(`cleardivert',
+  `pushdef(`_n', divnum)divert(`-1')undivert($@@)divert(_n)popdef(`_n')')
+@result{}
+divert(`1')one
+divert
+@result{}
+cleardivert
+@result{}
+undivert
+@result{}one
+@result{}
+define(`cleardivert',
+  `pushdef(`_num', divnum)divert(`-1')ifelse(`$#', `0',
+    `undivert`'', `undivert($@@)')divert(_num)popdef(`_num')')
+@result{}
+divert(`2')two
+divert
+@result{}
+cleardivert
+@result{}
+undivert
+@result{}
+@end example
+
+@node Improved fatal_error
+@section Solution for @code{fatal_error}
+
+The @code{fatal_error} macro (@pxref{M4exit}) is not robust to versions
+of @acronym{GNU} M4 earlier than 1.4.8, where invoking
+@code{@w{__file__}} (@pxref{Location}) inside @code{m4wrap} would result
+in an empty string, and @code{@w{__line__}} resulted in @samp{0} even
+though all files start at line 1.  Furthermore, versions earlier than
+1.4.6 did not support the @code{@w{__program__}} macro.  If you want
+@code{fatal_error} to work across the entire 1.4.x release series, a
+better implementation would be:
+
+@example
+define(`fatal_error',
+  `errprint(ifdef(`__program__', `__program__', ``m4'')'dnl
+`:ifelse(__line__, `0', `',
+    `__file__:__line__:')` fatal error: $*
+')m4exit(`1')')
+@result{}
+m4wrap(`divnum(`demo of internal message')
+fatal_error(`inside wrapped text')')
+@result{}
+^D
+@error{}m4:stdin:6: Warning: excess arguments to builtin `divnum' ignored
+@result{}0
+@error{}m4:stdin:6: fatal error: inside wrapped text
+@end example
+
+@c ========================================================== Appendices
+
+@node Copying This Manual
+@appendix How to make copies of this manual
+@cindex License
+
+@menu
+* GNU Free Documentation License::  License for copying this manual
+@end menu
+
+@include fdl.texi
+
+@node Indices
+@appendix Indices of concepts and macros
+
+@menu
+* Concept index::               Index for many concepts
+* Macro index::                 Index for all @code{m4} macros
+@end menu
+
+@node Concept index
+@appendixsec Index for many concepts
+
+@printindex cp
+
+@node Macro index
+@appendixsec Index for all @code{m4} macros
+
+References are exclusively to the places where a builtin is introduced
+the first time.
+
+@iftex
+@sp 1
+@end iftex
+
+@printindex fn
+
+@bye
+
+@c Local Variables:
+@c coding: ISO-8859-1
+@c fill-column: 72
+@c ispell-local-dictionary: "american"
+@c indent-tabs-mode: nil
+@c whitespace-check-buffer-indent: nil
+@c End:
diff --git a/src/bin/m4/doc/mdate-sh b/src/bin/m4/doc/mdate-sh
new file mode 100755
index 0000000000..cd916c0a34
--- /dev/null
+++ b/src/bin/m4/doc/mdate-sh
@@ -0,0 +1,201 @@
+#!/bin/sh
+# Get modification time of a file or directory and pretty-print it.
+
+scriptversion=2005-06-29.22
+
+# Copyright (C) 1995, 1996, 1997, 2003, 2004, 2005 Free Software
+# Foundation, Inc.
+# written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, June 1995
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+# This file is maintained in Automake, please report
+# bugs to <bug-automake@gnu.org> or send patches to
+# <automake-patches@gnu.org>.
+
+case $1 in
+  '')
+     echo "$0: No file.  Try \`$0 --help' for more information." 1>&2
+     exit 1;
+     ;;
+  -h | --h*)
+    cat <<\EOF
+Usage: mdate-sh [--help] [--version] FILE
+
+Pretty-print the modification time of FILE.
+
+Report bugs to <bug-automake@gnu.org>.
+EOF
+    exit $?
+    ;;
+  -v | --v*)
+    echo "mdate-sh $scriptversion"
+    exit $?
+    ;;
+esac
+
+# Prevent date giving response in another language.
+LANG=C
+export LANG
+LC_ALL=C
+export LC_ALL
+LC_TIME=C
+export LC_TIME
+
+# GNU ls changes its time format in response to the TIME_STYLE
+# variable.  Since we cannot assume `unset' works, revert this
+# variable to its documented default.
+if test "${TIME_STYLE+set}" = set; then
+  TIME_STYLE=posix-long-iso
+  export TIME_STYLE
+fi
+
+save_arg1=$1
+
+# Find out how to get the extended ls output of a file or directory.
+if ls -L /dev/null 1>/dev/null 2>&1; then
+  ls_command='ls -L -l -d'
+else
+  ls_command='ls -l -d'
+fi
+
+# A `ls -l' line looks as follows on OS/2.
+#  drwxrwx---        0 Aug 11  2001 foo
+# This differs from Unix, which adds ownership information.
+#  drwxrwx---   2 root  root      4096 Aug 11  2001 foo
+#
+# To find the date, we split the line on spaces and iterate on words
+# until we find a month.  This cannot work with files whose owner is a
+# user named `Jan', or `Feb', etc.  However, it's unlikely that `/'
+# will be owned by a user whose name is a month.  So we first look at
+# the extended ls output of the root directory to decide how many
+# words should be skipped to get the date.
+
+# On HPUX /bin/sh, "set" interprets "-rw-r--r--" as options, so the "x" below.
+set x`ls -l -d /`
+
+# Find which argument is the month.
+month=
+command=
+until test $month
+do
+  shift
+  # Add another shift to the command.
+  command="$command shift;"
+  case $1 in
+    Jan) month=January; nummonth=1;;
+    Feb) month=February; nummonth=2;;
+    Mar) month=March; nummonth=3;;
+    Apr) month=April; nummonth=4;;
+    May) month=May; nummonth=5;;
+    Jun) month=June; nummonth=6;;
+    Jul) month=July; nummonth=7;;
+    Aug) month=August; nummonth=8;;
+    Sep) month=September; nummonth=9;;
+    Oct) month=October; nummonth=10;;
+    Nov) month=November; nummonth=11;;
+    Dec) month=December; nummonth=12;;
+  esac
+done
+
+# Get the extended ls output of the file or directory.
+set dummy x`eval "$ls_command \"\$save_arg1\""`
+
+# Remove all preceding arguments
+eval $command
+
+# Because of the dummy argument above, month is in $2.
+#
+# On a POSIX system, we should have
+#
+# $# = 5
+# $1 = file size
+# $2 = month
+# $3 = day
+# $4 = year or time
+# $5 = filename
+#
+# On Darwin 7.7.0 and 7.6.0, we have
+#
+# $# = 4
+# $1 = day
+# $2 = month
+# $3 = year or time
+# $4 = filename
+
+# Get the month.
+case $2 in
+  Jan) month=January; nummonth=1;;
+  Feb) month=February; nummonth=2;;
+  Mar) month=March; nummonth=3;;
+  Apr) month=April; nummonth=4;;
+  May) month=May; nummonth=5;;
+  Jun) month=June; nummonth=6;;
+  Jul) month=July; nummonth=7;;
+  Aug) month=August; nummonth=8;;
+  Sep) month=September; nummonth=9;;
+  Oct) month=October; nummonth=10;;
+  Nov) month=November; nummonth=11;;
+  Dec) month=December; nummonth=12;;
+esac
+
+case $3 in
+  ???*) day=$1;;
+  *) day=$3; shift;;
+esac
+
+# Here we have to deal with the problem that the ls output gives either
+# the time of day or the year.
+case $3 in
+  *:*) set `date`; eval year=\$$#
+       case $2 in
+	 Jan) nummonthtod=1;;
+	 Feb) nummonthtod=2;;
+	 Mar) nummonthtod=3;;
+	 Apr) nummonthtod=4;;
+	 May) nummonthtod=5;;
+	 Jun) nummonthtod=6;;
+	 Jul) nummonthtod=7;;
+	 Aug) nummonthtod=8;;
+	 Sep) nummonthtod=9;;
+	 Oct) nummonthtod=10;;
+	 Nov) nummonthtod=11;;
+	 Dec) nummonthtod=12;;
+       esac
+       # For the first six month of the year the time notation can also
+       # be used for files modified in the last year.
+       if (expr $nummonth \> $nummonthtod) > /dev/null;
+       then
+	 year=`expr $year - 1`
+       fi;;
+  *) year=$3;;
+esac
+
+# The result.
+echo $day $month $year
+
+# Local Variables:
+# mode: shell-script
+# sh-indentation: 2
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-end: "$"
+# End:
diff --git a/src/bin/m4/doc/stamp-vti b/src/bin/m4/doc/stamp-vti
new file mode 100644
index 0000000000..c9d4e2fb98
--- /dev/null
+++ b/src/bin/m4/doc/stamp-vti
@@ -0,0 +1,4 @@
+@set UPDATED 20 November 2006
+@set UPDATED-MONTH November 2006
+@set EDITION 1.4.8
+@set VERSION 1.4.8
diff --git a/src/bin/m4/doc/texinfo.tex b/src/bin/m4/doc/texinfo.tex
new file mode 100644
index 0000000000..ab95370db4
--- /dev/null
+++ b/src/bin/m4/doc/texinfo.tex
@@ -0,0 +1,7483 @@
+% texinfo.tex -- TeX macros to handle Texinfo files.
+%
+% Load plain if necessary, i.e., if running under initex.
+\expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
+%
+\def\texinfoversion{2006-10-15.13}
+%
+% Copyright (C) 1985, 1986, 1988, 1990, 1991, 1992, 1993, 1994, 1995,
+% 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free
+% Software Foundation, Inc.
+%
+% This texinfo.tex file is free software; you can redistribute it and/or
+% modify it under the terms of the GNU General Public License as
+% published by the Free Software Foundation; either version 2, or (at
+% your option) any later version.
+%
+% This texinfo.tex file is distributed in the hope that it will be
+% useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+% of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+% General Public License for more details.
+%
+% You should have received a copy of the GNU General Public License
+% along with this texinfo.tex file; see the file COPYING.  If not, write
+% to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+% Boston, MA 02110-1301, USA.
+%
+% As a special exception, when this file is read by TeX when processing
+% a Texinfo source document, you may use the result without
+% restriction.  (This has been our intent since Texinfo was invented.)
+%
+% Please try the latest version of texinfo.tex before submitting bug
+% reports; you can get the latest version from:
+%   http://www.gnu.org/software/texinfo/ (the Texinfo home page), or
+%   ftp://tug.org/tex/texinfo.tex
+%     (and all CTAN mirrors, see http://www.ctan.org).
+% The texinfo.tex in any given distribution could well be out
+% of date, so if that's what you're using, please check.
+%
+% Send bug reports to bug-texinfo@gnu.org.  Please include including a
+% complete document in each bug report with which we can reproduce the
+% problem.  Patches are, of course, greatly appreciated.
+%
+% To process a Texinfo manual with TeX, it's most reliable to use the
+% texi2dvi shell script that comes with the distribution.  For a simple
+% manual foo.texi, however, you can get away with this:
+%   tex foo.texi
+%   texindex foo.??
+%   tex foo.texi
+%   tex foo.texi
+%   dvips foo.dvi -o  # or whatever; this makes foo.ps.
+% The extra TeX runs get the cross-reference information correct.
+% Sometimes one run after texindex suffices, and sometimes you need more
+% than two; texi2dvi does it as many times as necessary.
+%
+% It is possible to adapt texinfo.tex for other languages, to some
+% extent.  You can get the existing language-specific files from the
+% full Texinfo distribution.
+%
+% The GNU Texinfo home page is http://www.gnu.org/software/texinfo.
+
+
+\message{Loading texinfo [version \texinfoversion]:}
+
+% If in a .fmt file, print the version number
+% and turn on active characters that we couldn't do earlier because
+% they might have appeared in the input file name.
+\everyjob{\message{[Texinfo version \texinfoversion]}%
+  \catcode`+=\active \catcode`\_=\active}
+
+\message{Basics,}
+\chardef\other=12
+
+% We never want plain's \outer definition of \+ in Texinfo.
+% For @tex, we can use \tabalign.
+\let\+ = \relax
+
+% Save some plain tex macros whose names we will redefine.
+\let\ptexb=\b
+\let\ptexbullet=\bullet
+\let\ptexc=\c
+\let\ptexcomma=\,
+\let\ptexdot=\.
+\let\ptexdots=\dots
+\let\ptexend=\end
+\let\ptexequiv=\equiv
+\let\ptexexclam=\!
+\let\ptexfootnote=\footnote
+\let\ptexgtr=>
+\let\ptexhat=^
+\let\ptexi=\i
+\let\ptexindent=\indent
+\let\ptexinsert=\insert
+\let\ptexlbrace=\{
+\let\ptexless=<
+\let\ptexnewwrite\newwrite
+\let\ptexnoindent=\noindent
+\let\ptexplus=+
+\let\ptexrbrace=\}
+\let\ptexslash=\/
+\let\ptexstar=\*
+\let\ptext=\t
+
+% If this character appears in an error message or help string, it
+% starts a new line in the output.
+\newlinechar = `^^J
+
+% Use TeX 3.0's \inputlineno to get the line number, for better error
+% messages, but if we're using an old version of TeX, don't do anything.
+%
+\ifx\inputlineno\thisisundefined
+  \let\linenumber = \empty % Pre-3.0.
+\else
+  \def\linenumber{l.\the\inputlineno:\space}
+\fi
+
+% Set up fixed words for English if not already set.
+\ifx\putwordAppendix\undefined  \gdef\putwordAppendix{Appendix}\fi
+\ifx\putwordChapter\undefined   \gdef\putwordChapter{Chapter}\fi
+\ifx\putwordfile\undefined      \gdef\putwordfile{file}\fi
+\ifx\putwordin\undefined        \gdef\putwordin{in}\fi
+\ifx\putwordIndexIsEmpty\undefined     \gdef\putwordIndexIsEmpty{(Index is empty)}\fi
+\ifx\putwordIndexNonexistent\undefined \gdef\putwordIndexNonexistent{(Index is nonexistent)}\fi
+\ifx\putwordInfo\undefined      \gdef\putwordInfo{Info}\fi
+\ifx\putwordInstanceVariableof\undefined \gdef\putwordInstanceVariableof{Instance Variable of}\fi
+\ifx\putwordMethodon\undefined  \gdef\putwordMethodon{Method on}\fi
+\ifx\putwordNoTitle\undefined   \gdef\putwordNoTitle{No Title}\fi
+\ifx\putwordof\undefined        \gdef\putwordof{of}\fi
+\ifx\putwordon\undefined        \gdef\putwordon{on}\fi
+\ifx\putwordpage\undefined      \gdef\putwordpage{page}\fi
+\ifx\putwordsection\undefined   \gdef\putwordsection{section}\fi
+\ifx\putwordSection\undefined   \gdef\putwordSection{Section}\fi
+\ifx\putwordsee\undefined       \gdef\putwordsee{see}\fi
+\ifx\putwordSee\undefined       \gdef\putwordSee{See}\fi
+\ifx\putwordShortTOC\undefined  \gdef\putwordShortTOC{Short Contents}\fi
+\ifx\putwordTOC\undefined       \gdef\putwordTOC{Table of Contents}\fi
+%
+\ifx\putwordMJan\undefined \gdef\putwordMJan{January}\fi
+\ifx\putwordMFeb\undefined \gdef\putwordMFeb{February}\fi
+\ifx\putwordMMar\undefined \gdef\putwordMMar{March}\fi
+\ifx\putwordMApr\undefined \gdef\putwordMApr{April}\fi
+\ifx\putwordMMay\undefined \gdef\putwordMMay{May}\fi
+\ifx\putwordMJun\undefined \gdef\putwordMJun{June}\fi
+\ifx\putwordMJul\undefined \gdef\putwordMJul{July}\fi
+\ifx\putwordMAug\undefined \gdef\putwordMAug{August}\fi
+\ifx\putwordMSep\undefined \gdef\putwordMSep{September}\fi
+\ifx\putwordMOct\undefined \gdef\putwordMOct{October}\fi
+\ifx\putwordMNov\undefined \gdef\putwordMNov{November}\fi
+\ifx\putwordMDec\undefined \gdef\putwordMDec{December}\fi
+%
+\ifx\putwordDefmac\undefined    \gdef\putwordDefmac{Macro}\fi
+\ifx\putwordDefspec\undefined   \gdef\putwordDefspec{Special Form}\fi
+\ifx\putwordDefvar\undefined    \gdef\putwordDefvar{Variable}\fi
+\ifx\putwordDefopt\undefined    \gdef\putwordDefopt{User Option}\fi
+\ifx\putwordDeffunc\undefined   \gdef\putwordDeffunc{Function}\fi
+
+% Since the category of space is not known, we have to be careful.
+\chardef\spacecat = 10
+\def\spaceisspace{\catcode`\ =\spacecat}
+
+% sometimes characters are active, so we need control sequences.
+\chardef\colonChar = `\:
+\chardef\commaChar = `\,
+\chardef\dashChar  = `\-
+\chardef\dotChar   = `\.
+\chardef\exclamChar= `\!
+\chardef\lquoteChar= `\`
+\chardef\questChar = `\?
+\chardef\rquoteChar= `\'
+\chardef\semiChar  = `\;
+\chardef\underChar = `\_
+
+% Ignore a token.
+%
+\def\gobble#1{}
+
+% The following is used inside several \edef's.
+\def\makecsname#1{\expandafter\noexpand\csname#1\endcsname}
+
+% Hyphenation fixes.
+\hyphenation{
+  Flor-i-da Ghost-script Ghost-view Mac-OS Post-Script
+  ap-pen-dix bit-map bit-maps
+  data-base data-bases eshell fall-ing half-way long-est man-u-script
+  man-u-scripts mini-buf-fer mini-buf-fers over-view par-a-digm
+  par-a-digms rath-er rec-tan-gu-lar ro-bot-ics se-vere-ly set-up spa-ces
+  spell-ing spell-ings
+  stand-alone strong-est time-stamp time-stamps which-ever white-space
+  wide-spread wrap-around
+}
+
+% Margin to add to right of even pages, to left of odd pages.
+\newdimen\bindingoffset
+\newdimen\normaloffset
+\newdimen\pagewidth \newdimen\pageheight
+
+% For a final copy, take out the rectangles
+% that mark overfull boxes (in case you have decided
+% that the text looks ok even though it passes the margin).
+%
+\def\finalout{\overfullrule=0pt}
+
+% @| inserts a changebar to the left of the current line.  It should
+% surround any changed text.  This approach does *not* work if the
+% change spans more than two lines of output.  To handle that, we would
+% have adopt a much more difficult approach (putting marks into the main
+% vertical list for the beginning and end of each change).
+%
+\def\|{%
+  % \vadjust can only be used in horizontal mode.
+  \leavevmode
+  %
+  % Append this vertical mode material after the current line in the output.
+  \vadjust{%
+    % We want to insert a rule with the height and depth of the current
+    % leading; that is exactly what \strutbox is supposed to record.
+    \vskip-\baselineskip
+    %
+    % \vadjust-items are inserted at the left edge of the type.  So
+    % the \llap here moves out into the left-hand margin.
+    \llap{%
+      %
+      % For a thicker or thinner bar, change the `1pt'.
+      \vrule height\baselineskip width1pt
+      %
+      % This is the space between the bar and the text.
+      \hskip 12pt
+    }%
+  }%
+}
+
+% Sometimes it is convenient to have everything in the transcript file
+% and nothing on the terminal.  We don't just call \tracingall here,
+% since that produces some useless output on the terminal.  We also make
+% some effort to order the tracing commands to reduce output in the log
+% file; cf. trace.sty in LaTeX.
+%
+\def\gloggingall{\begingroup \globaldefs = 1 \loggingall \endgroup}%
+\def\loggingall{%
+  \tracingstats2
+  \tracingpages1
+  \tracinglostchars2  % 2 gives us more in etex
+  \tracingparagraphs1
+  \tracingoutput1
+  \tracingmacros2
+  \tracingrestores1
+  \showboxbreadth\maxdimen \showboxdepth\maxdimen
+  \ifx\eTeXversion\undefined\else % etex gives us more logging
+    \tracingscantokens1
+    \tracingifs1
+    \tracinggroups1
+    \tracingnesting2
+    \tracingassigns1
+  \fi
+  \tracingcommands3  % 3 gives us more in etex
+  \errorcontextlines16
+}%
+
+% add check for \lastpenalty to plain's definitions.  If the last thing
+% we did was a \nobreak, we don't want to insert more space.
+%
+\def\smallbreak{\ifnum\lastpenalty<10000\par\ifdim\lastskip<\smallskipamount
+  \removelastskip\penalty-50\smallskip\fi\fi}
+\def\medbreak{\ifnum\lastpenalty<10000\par\ifdim\lastskip<\medskipamount
+  \removelastskip\penalty-100\medskip\fi\fi}
+\def\bigbreak{\ifnum\lastpenalty<10000\par\ifdim\lastskip<\bigskipamount
+  \removelastskip\penalty-200\bigskip\fi\fi}
+
+% For @cropmarks command.
+% Do @cropmarks to get crop marks.
+%
+\newif\ifcropmarks
+\let\cropmarks = \cropmarkstrue
+%
+% Dimensions to add cropmarks at corners.
+% Added by P. A. MacKay, 12 Nov. 1986
+%
+\newdimen\outerhsize \newdimen\outervsize % set by the paper size routines
+\newdimen\cornerlong  \cornerlong=1pc
+\newdimen\cornerthick \cornerthick=.3pt
+\newdimen\topandbottommargin \topandbottommargin=.75in
+
+% Main output routine.
+\chardef\PAGE = 255
+\output = {\onepageout{\pagecontents\PAGE}}
+
+\newbox\headlinebox
+\newbox\footlinebox
+
+% \onepageout takes a vbox as an argument.  Note that \pagecontents
+% does insertions, but you have to call it yourself.
+\def\onepageout#1{%
+  \ifcropmarks \hoffset=0pt \else \hoffset=\normaloffset \fi
+  %
+  \ifodd\pageno  \advance\hoffset by \bindingoffset
+  \else \advance\hoffset by -\bindingoffset\fi
+  %
+  % Do this outside of the \shipout so @code etc. will be expanded in
+  % the headline as they should be, not taken literally (outputting ''code).
+  \setbox\headlinebox = \vbox{\let\hsize=\pagewidth \makeheadline}%
+  \setbox\footlinebox = \vbox{\let\hsize=\pagewidth \makefootline}%
+  %
+  {%
+    % Have to do this stuff outside the \shipout because we want it to
+    % take effect in \write's, yet the group defined by the \vbox ends
+    % before the \shipout runs.
+    %
+    \indexdummies         % don't expand commands in the output.
+    \normalturnoffactive  % \ in index entries must not stay \, e.g., if
+               % the page break happens to be in the middle of an example.
+               % We don't want .vr (or whatever) entries like this:
+               % \entry{{\tt \indexbackslash }acronym}{32}{\code {\acronym}}
+               % "\acronym" won't work when it's read back in;
+               % it needs to be 
+               % {\code {{\tt \backslashcurfont }acronym}
+    \shipout\vbox{%
+      % Do this early so pdf references go to the beginning of the page.
+      \ifpdfmakepagedest \pdfdest name{\the\pageno} xyz\fi
+      %
+      \ifcropmarks \vbox to \outervsize\bgroup
+        \hsize = \outerhsize
+        \vskip-\topandbottommargin
+        \vtop to0pt{%
+          \line{\ewtop\hfil\ewtop}%
+          \nointerlineskip
+          \line{%
+            \vbox{\moveleft\cornerthick\nstop}%
+            \hfill
+            \vbox{\moveright\cornerthick\nstop}%
+          }%
+          \vss}%
+        \vskip\topandbottommargin
+        \line\bgroup
+          \hfil % center the page within the outer (page) hsize.
+          \ifodd\pageno\hskip\bindingoffset\fi
+          \vbox\bgroup
+      \fi
+      %
+      \unvbox\headlinebox
+      \pagebody{#1}%
+      \ifdim\ht\footlinebox > 0pt
+        % Only leave this space if the footline is nonempty.
+        % (We lessened \vsize for it in \oddfootingyyy.)
+        % The \baselineskip=24pt in plain's \makefootline has no effect.
+        \vskip 24pt
+        \unvbox\footlinebox
+      \fi
+      %
+      \ifcropmarks
+          \egroup % end of \vbox\bgroup
+        \hfil\egroup % end of (centering) \line\bgroup
+        \vskip\topandbottommargin plus1fill minus1fill
+        \boxmaxdepth = \cornerthick
+        \vbox to0pt{\vss
+          \line{%
+            \vbox{\moveleft\cornerthick\nsbot}%
+            \hfill
+            \vbox{\moveright\cornerthick\nsbot}%
+          }%
+          \nointerlineskip
+          \line{\ewbot\hfil\ewbot}%
+        }%
+      \egroup % \vbox from first cropmarks clause
+      \fi
+    }% end of \shipout\vbox
+  }% end of group with \indexdummies
+  \advancepageno
+  \ifnum\outputpenalty>-20000 \else\dosupereject\fi
+}
+
+\newinsert\margin \dimen\margin=\maxdimen
+
+\def\pagebody#1{\vbox to\pageheight{\boxmaxdepth=\maxdepth #1}}
+{\catcode`\@ =11
+\gdef\pagecontents#1{\ifvoid\topins\else\unvbox\topins\fi
+% marginal hacks, juha@viisa.uucp (Juha Takala)
+\ifvoid\margin\else % marginal info is present
+  \rlap{\kern\hsize\vbox to\z@{\kern1pt\box\margin \vss}}\fi
+\dimen@=\dp#1 \unvbox#1
+\ifvoid\footins\else\vskip\skip\footins\footnoterule \unvbox\footins\fi
+\ifr@ggedbottom \kern-\dimen@ \vfil \fi}
+}
+
+% Here are the rules for the cropmarks.  Note that they are
+% offset so that the space between them is truly \outerhsize or \outervsize
+% (P. A. MacKay, 12 November, 1986)
+%
+\def\ewtop{\vrule height\cornerthick depth0pt width\cornerlong}
+\def\nstop{\vbox
+  {\hrule height\cornerthick depth\cornerlong width\cornerthick}}
+\def\ewbot{\vrule height0pt depth\cornerthick width\cornerlong}
+\def\nsbot{\vbox
+  {\hrule height\cornerlong depth\cornerthick width\cornerthick}}
+
+% Parse an argument, then pass it to #1.  The argument is the rest of
+% the input line (except we remove a trailing comment).  #1 should be a
+% macro which expects an ordinary undelimited TeX argument.
+%
+\def\parsearg{\parseargusing{}}
+\def\parseargusing#1#2{%
+  \def\argtorun{#2}%
+  \begingroup
+    \obeylines
+    \spaceisspace
+    #1%
+    \parseargline\empty% Insert the \empty token, see \finishparsearg below.
+}
+
+{\obeylines %
+  \gdef\parseargline#1^^M{%
+    \endgroup % End of the group started in \parsearg.
+    \argremovecomment #1\comment\ArgTerm%
+  }%
+}
+
+% First remove any @comment, then any @c comment.
+\def\argremovecomment#1\comment#2\ArgTerm{\argremovec #1\c\ArgTerm}
+\def\argremovec#1\c#2\ArgTerm{\argcheckspaces#1\^^M\ArgTerm}
+
+% Each occurence of `\^^M' or `<space>\^^M' is replaced by a single space.
+%
+% \argremovec might leave us with trailing space, e.g.,
+%    @end itemize  @c foo
+% This space token undergoes the same procedure and is eventually removed
+% by \finishparsearg.
+%
+\def\argcheckspaces#1\^^M{\argcheckspacesX#1\^^M \^^M}
+\def\argcheckspacesX#1 \^^M{\argcheckspacesY#1\^^M}
+\def\argcheckspacesY#1\^^M#2\^^M#3\ArgTerm{%
+  \def\temp{#3}%
+  \ifx\temp\empty
+    % Do not use \next, perhaps the caller of \parsearg uses it; reuse \temp:
+    \let\temp\finishparsearg
+  \else
+    \let\temp\argcheckspaces
+  \fi
+  % Put the space token in:
+  \temp#1 #3\ArgTerm
+}
+
+% If a _delimited_ argument is enclosed in braces, they get stripped; so
+% to get _exactly_ the rest of the line, we had to prevent such situation.
+% We prepended an \empty token at the very beginning and we expand it now,
+% just before passing the control to \argtorun.
+% (Similarily, we have to think about #3 of \argcheckspacesY above: it is
+% either the null string, or it ends with \^^M---thus there is no danger
+% that a pair of braces would be stripped.
+%
+% But first, we have to remove the trailing space token.
+%
+\def\finishparsearg#1 \ArgTerm{\expandafter\argtorun\expandafter{#1}}
+
+% \parseargdef\foo{...}
+%	is roughly equivalent to
+% \def\foo{\parsearg\Xfoo}
+% \def\Xfoo#1{...}
+%
+% Actually, I use \csname\string\foo\endcsname, ie. \\foo, as it is my
+% favourite TeX trick.  --kasal, 16nov03
+
+\def\parseargdef#1{%
+  \expandafter \doparseargdef \csname\string#1\endcsname #1%
+}
+\def\doparseargdef#1#2{%
+  \def#2{\parsearg#1}%
+  \def#1##1%
+}
+
+% Several utility definitions with active space:
+{
+  \obeyspaces
+  \gdef\obeyedspace{ }
+
+  % Make each space character in the input produce a normal interword
+  % space in the output.  Don't allow a line break at this space, as this
+  % is used only in environments like @example, where each line of input
+  % should produce a line of output anyway.
+  %
+  \gdef\sepspaces{\obeyspaces\let =\tie}
+
+  % If an index command is used in an @example environment, any spaces
+  % therein should become regular spaces in the raw index file, not the
+  % expansion of \tie (\leavevmode \penalty \@M \ ).
+  \gdef\unsepspaces{\let =\space}
+}
+
+
+\def\flushcr{\ifx\par\lisppar \def\next##1{}\else \let\next=\relax \fi \next}
+
+% Define the framework for environments in texinfo.tex.  It's used like this:
+%
+%   \envdef\foo{...}
+%   \def\Efoo{...}
+%
+% It's the responsibility of \envdef to insert \begingroup before the
+% actual body; @end closes the group after calling \Efoo.  \envdef also
+% defines \thisenv, so the current environment is known; @end checks
+% whether the environment name matches.  The \checkenv macro can also be
+% used to check whether the current environment is the one expected.
+%
+% Non-false conditionals (@iftex, @ifset) don't fit into this, so they
+% are not treated as enviroments; they don't open a group.  (The
+% implementation of @end takes care not to call \endgroup in this
+% special case.)
+
+
+% At runtime, environments start with this:
+\def\startenvironment#1{\begingroup\def\thisenv{#1}}
+% initialize
+\let\thisenv\empty
+
+% ... but they get defined via ``\envdef\foo{...}'':
+\long\def\envdef#1#2{\def#1{\startenvironment#1#2}}
+\def\envparseargdef#1#2{\parseargdef#1{\startenvironment#1#2}}
+
+% Check whether we're in the right environment:
+\def\checkenv#1{%
+  \def\temp{#1}%
+  \ifx\thisenv\temp
+  \else
+    \badenverr
+  \fi
+}
+
+% Evironment mismatch, #1 expected:
+\def\badenverr{%
+  \errhelp = \EMsimple
+  \errmessage{This command can appear only \inenvironment\temp,
+    not \inenvironment\thisenv}%
+}
+\def\inenvironment#1{%
+  \ifx#1\empty
+    out of any environment%
+  \else
+    in environment \expandafter\string#1%
+  \fi
+}
+
+% @end foo executes the definition of \Efoo.
+% But first, it executes a specialized version of \checkenv
+%
+\parseargdef\end{%
+  \if 1\csname iscond.#1\endcsname
+  \else
+    % The general wording of \badenverr may not be ideal, but... --kasal, 06nov03
+    \expandafter\checkenv\csname#1\endcsname
+    \csname E#1\endcsname
+    \endgroup
+  \fi
+}
+
+\newhelp\EMsimple{Press RETURN to continue.}
+
+
+%% Simple single-character @ commands
+
+% @@ prints an @
+% Kludge this until the fonts are right (grr).
+\def\@{{\tt\char64}}
+
+% This is turned off because it was never documented
+% and you can use @w{...} around a quote to suppress ligatures.
+%% Define @` and @' to be the same as ` and '
+%% but suppressing ligatures.
+%\def\`{{`}}
+%\def\'{{'}}
+
+% Used to generate quoted braces.
+\def\mylbrace {{\tt\char123}}
+\def\myrbrace {{\tt\char125}}
+\let\{=\mylbrace
+\let\}=\myrbrace
+\begingroup
+  % Definitions to produce \{ and \} commands for indices,
+  % and @{ and @} for the aux/toc files.
+  \catcode`\{ = \other \catcode`\} = \other
+  \catcode`\[ = 1 \catcode`\] = 2
+  \catcode`\! = 0 \catcode`\\ = \other
+  !gdef!lbracecmd[\{]%
+  !gdef!rbracecmd[\}]%
+  !gdef!lbraceatcmd[@{]%
+  !gdef!rbraceatcmd[@}]%
+!endgroup
+
+% @comma{} to avoid , parsing problems.
+\let\comma = ,
+
+% Accents: @, @dotaccent @ringaccent @ubaraccent @udotaccent
+% Others are defined by plain TeX: @` @' @" @^ @~ @= @u @v @H.
+\let\, = \c
+\let\dotaccent = \.
+\def\ringaccent#1{{\accent23 #1}}
+\let\tieaccent = \t
+\let\ubaraccent = \b
+\let\udotaccent = \d
+
+% Other special characters: @questiondown @exclamdown @ordf @ordm
+% Plain TeX defines: @AA @AE @O @OE @L (plus lowercase versions) @ss.
+\def\questiondown{?`}
+\def\exclamdown{!`}
+\def\ordf{\leavevmode\raise1ex\hbox{\selectfonts\lllsize \underbar{a}}}
+\def\ordm{\leavevmode\raise1ex\hbox{\selectfonts\lllsize \underbar{o}}}
+
+% Dotless i and dotless j, used for accents.
+\def\imacro{i}
+\def\jmacro{j}
+\def\dotless#1{%
+  \def\temp{#1}%
+  \ifx\temp\imacro \ptexi
+  \else\ifx\temp\jmacro \j
+  \else \errmessage{@dotless can be used only with i or j}%
+  \fi\fi
+}
+
+% The \TeX{} logo, as in plain, but resetting the spacing so that a
+% period following counts as ending a sentence.  (Idea found in latex.)
+%
+\edef\TeX{\TeX \spacefactor=1000 }
+
+% @LaTeX{} logo.  Not quite the same results as the definition in
+% latex.ltx, since we use a different font for the raised A; it's most
+% convenient for us to use an explicitly smaller font, rather than using
+% the \scriptstyle font (since we don't reset \scriptstyle and
+% \scriptscriptstyle).
+%
+\def\LaTeX{%
+  L\kern-.36em
+  {\setbox0=\hbox{T}%
+   \vbox to \ht0{\hbox{\selectfonts\lllsize A}\vss}}%
+  \kern-.15em
+  \TeX
+}
+
+% Be sure we're in horizontal mode when doing a tie, since we make space
+% equivalent to this in @example-like environments. Otherwise, a space
+% at the beginning of a line will start with \penalty -- and
+% since \penalty is valid in vertical mode, we'd end up putting the
+% penalty on the vertical list instead of in the new paragraph.
+{\catcode`@ = 11
+ % Avoid using \@M directly, because that causes trouble
+ % if the definition is written into an index file.
+ \global\let\tiepenalty = \@M
+ \gdef\tie{\leavevmode\penalty\tiepenalty\ }
+}
+
+% @: forces normal size whitespace following.
+\def\:{\spacefactor=1000 }
+
+% @* forces a line break.
+\def\*{\hfil\break\hbox{}\ignorespaces}
+
+% @/ allows a line break.
+\let\/=\allowbreak
+
+% @. is an end-of-sentence period.
+\def\.{.\spacefactor=\endofsentencespacefactor\space}
+
+% @! is an end-of-sentence bang.
+\def\!{!\spacefactor=\endofsentencespacefactor\space}
+
+% @? is an end-of-sentence query.
+\def\?{?\spacefactor=\endofsentencespacefactor\space}
+
+% @frenchspacing on|off  says whether to put extra space after punctuation.
+% 
+\def\onword{on}
+\def\offword{off}
+%
+\parseargdef\frenchspacing{%
+  \def\temp{#1}%
+  \ifx\temp\onword \plainfrenchspacing
+  \else\ifx\temp\offword \plainnonfrenchspacing
+  \else
+    \errhelp = \EMsimple
+    \errmessage{Unknown @frenchspacing option `\temp', must be on/off}%
+  \fi\fi
+}
+
+% @w prevents a word break.  Without the \leavevmode, @w at the
+% beginning of a paragraph, when TeX is still in vertical mode, would
+% produce a whole line of output instead of starting the paragraph.
+\def\w#1{\leavevmode\hbox{#1}}
+
+% @group ... @end group forces ... to be all on one page, by enclosing
+% it in a TeX vbox.  We use \vtop instead of \vbox to construct the box
+% to keep its height that of a normal line.  According to the rules for
+% \topskip (p.114 of the TeXbook), the glue inserted is
+% max (\topskip - \ht (first item), 0).  If that height is large,
+% therefore, no glue is inserted, and the space between the headline and
+% the text is small, which looks bad.
+%
+% Another complication is that the group might be very large.  This can
+% cause the glue on the previous page to be unduly stretched, because it
+% does not have much material.  In this case, it's better to add an
+% explicit \vfill so that the extra space is at the bottom.  The
+% threshold for doing this is if the group is more than \vfilllimit
+% percent of a page (\vfilllimit can be changed inside of @tex).
+%
+\newbox\groupbox
+\def\vfilllimit{0.7}
+%
+\envdef\group{%
+  \ifnum\catcode`\^^M=\active \else
+    \errhelp = \groupinvalidhelp
+    \errmessage{@group invalid in context where filling is enabled}%
+  \fi
+  \startsavinginserts
+  %
+  \setbox\groupbox = \vtop\bgroup
+    % Do @comment since we are called inside an environment such as
+    % @example, where each end-of-line in the input causes an
+    % end-of-line in the output.  We don't want the end-of-line after
+    % the `@group' to put extra space in the output.  Since @group
+    % should appear on a line by itself (according to the Texinfo
+    % manual), we don't worry about eating any user text.
+    \comment
+}
+%
+% The \vtop produces a box with normal height and large depth; thus, TeX puts
+% \baselineskip glue before it, and (when the next line of text is done)
+% \lineskip glue after it.  Thus, space below is not quite equal to space
+% above.  But it's pretty close.
+\def\Egroup{%
+    % To get correct interline space between the last line of the group
+    % and the first line afterwards, we have to propagate \prevdepth.
+    \endgraf % Not \par, as it may have been set to \lisppar.
+    \global\dimen1 = \prevdepth
+  \egroup           % End the \vtop.
+  % \dimen0 is the vertical size of the group's box.
+  \dimen0 = \ht\groupbox  \advance\dimen0 by \dp\groupbox
+  % \dimen2 is how much space is left on the page (more or less).
+  \dimen2 = \pageheight   \advance\dimen2 by -\pagetotal
+  % if the group doesn't fit on the current page, and it's a big big
+  % group, force a page break.
+  \ifdim \dimen0 > \dimen2
+    \ifdim \pagetotal < \vfilllimit\pageheight
+      \page
+    \fi
+  \fi
+  \box\groupbox
+  \prevdepth = \dimen1
+  \checkinserts
+}
+%
+% TeX puts in an \escapechar (i.e., `@') at the beginning of the help
+% message, so this ends up printing `@group can only ...'.
+%
+\newhelp\groupinvalidhelp{%
+group can only be used in environments such as @example,^^J%
+where each line of input produces a line of output.}
+
+% @need space-in-mils
+% forces a page break if there is not space-in-mils remaining.
+
+\newdimen\mil  \mil=0.001in
+
+% Old definition--didn't work.
+%\parseargdef\need{\par %
+%% This method tries to make TeX break the page naturally
+%% if the depth of the box does not fit.
+%{\baselineskip=0pt%
+%\vtop to #1\mil{\vfil}\kern -#1\mil\nobreak
+%\prevdepth=-1000pt
+%}}
+
+\parseargdef\need{%
+  % Ensure vertical mode, so we don't make a big box in the middle of a
+  % paragraph.
+  \par
+  %
+  % If the @need value is less than one line space, it's useless.
+  \dimen0 = #1\mil
+  \dimen2 = \ht\strutbox
+  \advance\dimen2 by \dp\strutbox
+  \ifdim\dimen0 > \dimen2
+    %
+    % Do a \strut just to make the height of this box be normal, so the
+    % normal leading is inserted relative to the preceding line.
+    % And a page break here is fine.
+    \vtop to #1\mil{\strut\vfil}%
+    %
+    % TeX does not even consider page breaks if a penalty added to the
+    % main vertical list is 10000 or more.  But in order to see if the
+    % empty box we just added fits on the page, we must make it consider
+    % page breaks.  On the other hand, we don't want to actually break the
+    % page after the empty box.  So we use a penalty of 9999.
+    %
+    % There is an extremely small chance that TeX will actually break the
+    % page at this \penalty, if there are no other feasible breakpoints in
+    % sight.  (If the user is using lots of big @group commands, which
+    % almost-but-not-quite fill up a page, TeX will have a hard time doing
+    % good page breaking, for example.)  However, I could not construct an
+    % example where a page broke at this \penalty; if it happens in a real
+    % document, then we can reconsider our strategy.
+    \penalty9999
+    %
+    % Back up by the size of the box, whether we did a page break or not.
+    \kern -#1\mil
+    %
+    % Do not allow a page break right after this kern.
+    \nobreak
+  \fi
+}
+
+% @br   forces paragraph break (and is undocumented).
+
+\let\br = \par
+
+% @page forces the start of a new page.
+%
+\def\page{\par\vfill\supereject}
+
+% @exdent text....
+% outputs text on separate line in roman font, starting at standard page margin
+
+% This records the amount of indent in the innermost environment.
+% That's how much \exdent should take out.
+\newskip\exdentamount
+
+% This defn is used inside fill environments such as @defun.
+\parseargdef\exdent{\hfil\break\hbox{\kern -\exdentamount{\rm#1}}\hfil\break}
+
+% This defn is used inside nofill environments such as @example.
+\parseargdef\nofillexdent{{\advance \leftskip by -\exdentamount
+  \leftline{\hskip\leftskip{\rm#1}}}}
+
+% @inmargin{WHICH}{TEXT} puts TEXT in the WHICH margin next to the current
+% paragraph.  For more general purposes, use the \margin insertion
+% class.  WHICH is `l' or `r'.
+%
+\newskip\inmarginspacing \inmarginspacing=1cm
+\def\strutdepth{\dp\strutbox}
+%
+\def\doinmargin#1#2{\strut\vadjust{%
+  \nobreak
+  \kern-\strutdepth
+  \vtop to \strutdepth{%
+    \baselineskip=\strutdepth
+    \vss
+    % if you have multiple lines of stuff to put here, you'll need to
+    % make the vbox yourself of the appropriate size.
+    \ifx#1l%
+      \llap{\ignorespaces #2\hskip\inmarginspacing}%
+    \else
+      \rlap{\hskip\hsize \hskip\inmarginspacing \ignorespaces #2}%
+    \fi
+    \null
+  }%
+}}
+\def\inleftmargin{\doinmargin l}
+\def\inrightmargin{\doinmargin r}
+%
+% @inmargin{TEXT [, RIGHT-TEXT]}
+% (if RIGHT-TEXT is given, use TEXT for left page, RIGHT-TEXT for right;
+% else use TEXT for both).
+%
+\def\inmargin#1{\parseinmargin #1,,\finish}
+\def\parseinmargin#1,#2,#3\finish{% not perfect, but better than nothing.
+  \setbox0 = \hbox{\ignorespaces #2}%
+  \ifdim\wd0 > 0pt
+    \def\lefttext{#1}%  have both texts
+    \def\righttext{#2}%
+  \else
+    \def\lefttext{#1}%  have only one text
+    \def\righttext{#1}%
+  \fi
+  %
+  \ifodd\pageno
+    \def\temp{\inrightmargin\righttext}% odd page -> outside is right margin
+  \else
+    \def\temp{\inleftmargin\lefttext}%
+  \fi
+  \temp
+}
+
+% @include file    insert text of that file as input.
+%
+\def\include{\parseargusing\filenamecatcodes\includezzz}
+\def\includezzz#1{%
+  \pushthisfilestack
+  \def\thisfile{#1}%
+  {%
+    \makevalueexpandable
+    \def\temp{\input #1 }%
+    \expandafter
+  }\temp
+  \popthisfilestack
+}
+\def\filenamecatcodes{%
+  \catcode`\\=\other
+  \catcode`~=\other
+  \catcode`^=\other
+  \catcode`_=\other
+  \catcode`|=\other
+  \catcode`<=\other
+  \catcode`>=\other
+  \catcode`+=\other
+  \catcode`-=\other
+}
+
+\def\pushthisfilestack{%
+  \expandafter\pushthisfilestackX\popthisfilestack\StackTerm
+}
+\def\pushthisfilestackX{%
+  \expandafter\pushthisfilestackY\thisfile\StackTerm
+}
+\def\pushthisfilestackY #1\StackTerm #2\StackTerm {%
+  \gdef\popthisfilestack{\gdef\thisfile{#1}\gdef\popthisfilestack{#2}}%
+}
+
+\def\popthisfilestack{\errthisfilestackempty}
+\def\errthisfilestackempty{\errmessage{Internal error:
+  the stack of filenames is empty.}}
+
+\def\thisfile{}
+
+% @center line
+% outputs that line, centered.
+%
+\parseargdef\center{%
+  \ifhmode
+    \let\next\centerH
+  \else
+    \let\next\centerV
+  \fi
+  \next{\hfil \ignorespaces#1\unskip \hfil}%
+}
+\def\centerH#1{%
+  {%
+    \hfil\break
+    \advance\hsize by -\leftskip
+    \advance\hsize by -\rightskip
+    \line{#1}%
+    \break
+  }%
+}
+\def\centerV#1{\line{\kern\leftskip #1\kern\rightskip}}
+
+% @sp n   outputs n lines of vertical space
+
+\parseargdef\sp{\vskip #1\baselineskip}
+
+% @comment ...line which is ignored...
+% @c is the same as @comment
+% @ignore ... @end ignore  is another way to write a comment
+
+\def\comment{\begingroup \catcode`\^^M=\other%
+\catcode`\@=\other \catcode`\{=\other \catcode`\}=\other%
+\commentxxx}
+{\catcode`\^^M=\other \gdef\commentxxx#1^^M{\endgroup}}
+
+\let\c=\comment
+
+% @paragraphindent NCHARS
+% We'll use ems for NCHARS, close enough.
+% NCHARS can also be the word `asis' or `none'.
+% We cannot feasibly implement @paragraphindent asis, though.
+%
+\def\asisword{asis} % no translation, these are keywords
+\def\noneword{none}
+%
+\parseargdef\paragraphindent{%
+  \def\temp{#1}%
+  \ifx\temp\asisword
+  \else
+    \ifx\temp\noneword
+      \defaultparindent = 0pt
+    \else
+      \defaultparindent = #1em
+    \fi
+  \fi
+  \parindent = \defaultparindent
+}
+
+% @exampleindent NCHARS
+% We'll use ems for NCHARS like @paragraphindent.
+% It seems @exampleindent asis isn't necessary, but
+% I preserve it to make it similar to @paragraphindent.
+\parseargdef\exampleindent{%
+  \def\temp{#1}%
+  \ifx\temp\asisword
+  \else
+    \ifx\temp\noneword
+      \lispnarrowing = 0pt
+    \else
+      \lispnarrowing = #1em
+    \fi
+  \fi
+}
+
+% @firstparagraphindent WORD
+% If WORD is `none', then suppress indentation of the first paragraph
+% after a section heading.  If WORD is `insert', then do indent at such
+% paragraphs.
+%
+% The paragraph indentation is suppressed or not by calling
+% \suppressfirstparagraphindent, which the sectioning commands do.
+% We switch the definition of this back and forth according to WORD.
+% By default, we suppress indentation.
+%
+\def\suppressfirstparagraphindent{\dosuppressfirstparagraphindent}
+\def\insertword{insert}
+%
+\parseargdef\firstparagraphindent{%
+  \def\temp{#1}%
+  \ifx\temp\noneword
+    \let\suppressfirstparagraphindent = \dosuppressfirstparagraphindent
+  \else\ifx\temp\insertword
+    \let\suppressfirstparagraphindent = \relax
+  \else
+    \errhelp = \EMsimple
+    \errmessage{Unknown @firstparagraphindent option `\temp'}%
+  \fi\fi
+}
+
+% Here is how we actually suppress indentation.  Redefine \everypar to
+% \kern backwards by \parindent, and then reset itself to empty.
+%
+% We also make \indent itself not actually do anything until the next
+% paragraph.
+%
+\gdef\dosuppressfirstparagraphindent{%
+  \gdef\indent{%
+    \restorefirstparagraphindent
+    \indent
+  }%
+  \gdef\noindent{%
+    \restorefirstparagraphindent
+    \noindent
+  }%
+  \global\everypar = {%
+    \kern -\parindent
+    \restorefirstparagraphindent
+  }%
+}
+
+\gdef\restorefirstparagraphindent{%
+  \global \let \indent = \ptexindent
+  \global \let \noindent = \ptexnoindent
+  \global \everypar = {}%
+}
+
+
+% @asis just yields its argument.  Used with @table, for example.
+%
+\def\asis#1{#1}
+
+% @math outputs its argument in math mode.
+%
+% One complication: _ usually means subscripts, but it could also mean
+% an actual _ character, as in @math{@var{some_variable} + 1}.  So make
+% _ active, and distinguish by seeing if the current family is \slfam,
+% which is what @var uses.
+{
+  \catcode`\_ = \active
+  \gdef\mathunderscore{%
+    \catcode`\_=\active
+    \def_{\ifnum\fam=\slfam \_\else\sb\fi}%
+  }
+}
+% Another complication: we want \\ (and @\) to output a \ character.
+% FYI, plain.tex uses \\ as a temporary control sequence (why?), but
+% this is not advertised and we don't care.  Texinfo does not
+% otherwise define @\.
+%
+% The \mathchar is class=0=ordinary, family=7=ttfam, position=5C=\.
+\def\mathbackslash{\ifnum\fam=\ttfam \mathchar"075C \else\backslash \fi}
+%
+\def\math{%
+  \tex
+  \mathunderscore
+  \let\\ = \mathbackslash
+  \mathactive
+  $\finishmath
+}
+\def\finishmath#1{#1$\endgroup}  % Close the group opened by \tex.
+
+% Some active characters (such as <) are spaced differently in math.
+% We have to reset their definitions in case the @math was an argument
+% to a command which sets the catcodes (such as @item or @section).
+%
+{
+  \catcode`^ = \active
+  \catcode`< = \active
+  \catcode`> = \active
+  \catcode`+ = \active
+  \gdef\mathactive{%
+    \let^ = \ptexhat
+    \let< = \ptexless
+    \let> = \ptexgtr
+    \let+ = \ptexplus
+  }
+}
+
+% @bullet and @minus need the same treatment as @math, just above.
+\def\bullet{$\ptexbullet$}
+\def\minus{$-$}
+
+% @dots{} outputs an ellipsis using the current font.
+% We do .5em per period so that it has the same spacing in the cm
+% typewriter fonts as three actual period characters; on the other hand,
+% in other typewriter fonts three periods are wider than 1.5em.  So do
+% whichever is larger.
+%
+\def\dots{%
+  \leavevmode
+  \setbox0=\hbox{...}% get width of three periods
+  \ifdim\wd0 > 1.5em
+    \dimen0 = \wd0
+  \else
+    \dimen0 = 1.5em
+  \fi
+  \hbox to \dimen0{%
+    \hskip 0pt plus.25fil
+    .\hskip 0pt plus1fil
+    .\hskip 0pt plus1fil
+    .\hskip 0pt plus.5fil
+  }%
+}
+
+% @enddots{} is an end-of-sentence ellipsis.
+%
+\def\enddots{%
+  \dots
+  \spacefactor=\endofsentencespacefactor
+}
+
+% @comma{} is so commas can be inserted into text without messing up
+% Texinfo's parsing.
+%
+\let\comma = ,
+
+% @refill is a no-op.
+\let\refill=\relax
+
+% If working on a large document in chapters, it is convenient to
+% be able to disable indexing, cross-referencing, and contents, for test runs.
+% This is done with @novalidate (before @setfilename).
+%
+\newif\iflinks \linkstrue % by default we want the aux files.
+\let\novalidate = \linksfalse
+
+% @setfilename is done at the beginning of every texinfo file.
+% So open here the files we need to have open while reading the input.
+% This makes it possible to make a .fmt file for texinfo.
+\def\setfilename{%
+   \fixbackslash  % Turn off hack to swallow `\input texinfo'.
+   \iflinks
+     \tryauxfile
+     % Open the new aux file.  TeX will close it automatically at exit.
+     \immediate\openout\auxfile=\jobname.aux
+   \fi % \openindices needs to do some work in any case.
+   \openindices
+   \let\setfilename=\comment % Ignore extra @setfilename cmds.
+   %
+   % If texinfo.cnf is present on the system, read it.
+   % Useful for site-wide @afourpaper, etc.
+   \openin 1 texinfo.cnf
+   \ifeof 1 \else \input texinfo.cnf \fi
+   \closein 1
+   %
+   \comment % Ignore the actual filename.
+}
+
+% Called from \setfilename.
+%
+\def\openindices{%
+  \newindex{cp}%
+  \newcodeindex{fn}%
+  \newcodeindex{vr}%
+  \newcodeindex{tp}%
+  \newcodeindex{ky}%
+  \newcodeindex{pg}%
+}
+
+% @bye.
+\outer\def\bye{\pagealignmacro\tracingstats=1\ptexend}
+
+
+\message{pdf,}
+% adobe `portable' document format
+\newcount\tempnum
+\newcount\lnkcount
+\newtoks\filename
+\newcount\filenamelength
+\newcount\pgn
+\newtoks\toksA
+\newtoks\toksB
+\newtoks\toksC
+\newtoks\toksD
+\newbox\boxA
+\newcount\countA
+\newif\ifpdf
+\newif\ifpdfmakepagedest
+
+% when pdftex is run in dvi mode, \pdfoutput is defined (so \pdfoutput=1
+% can be set).  So we test for \relax and 0 as well as \undefined,
+% borrowed from ifpdf.sty.
+\ifx\pdfoutput\undefined
+\else
+  \ifx\pdfoutput\relax
+  \else
+    \ifcase\pdfoutput
+    \else
+      \pdftrue
+    \fi
+  \fi
+\fi
+
+% PDF uses PostScript string constants for the names of xref targets,
+% for display in the outlines, and in other places.  Thus, we have to
+% double any backslashes.  Otherwise, a name like "\node" will be
+% interpreted as a newline (\n), followed by o, d, e.  Not good.
+% http://www.ntg.nl/pipermail/ntg-pdftex/2004-July/000654.html
+% (and related messages, the final outcome is that it is up to the TeX
+% user to double the backslashes and otherwise make the string valid, so
+% that's what we do).
+
+% double active backslashes.
+% 
+{\catcode`\@=0 \catcode`\\=\active
+ @gdef@activebackslashdouble{%
+   @catcode`@\=@active
+   @let\=@doublebackslash}
+}
+
+% To handle parens, we must adopt a different approach, since parens are
+% not active characters.  hyperref.dtx (which has the same problem as
+% us) handles it with this amazing macro to replace tokens.  I've
+% tinkered with it a little for texinfo, but it's definitely from there.
+% 
+% #1 is the tokens to replace.
+% #2 is the replacement.
+% #3 is the control sequence with the string.
+% 
+\def\HyPsdSubst#1#2#3{%
+  \def\HyPsdReplace##1#1##2\END{%
+    ##1%
+    \ifx\\##2\\%
+    \else
+      #2%
+      \HyReturnAfterFi{%
+        \HyPsdReplace##2\END
+      }%
+    \fi
+  }%
+  \xdef#3{\expandafter\HyPsdReplace#3#1\END}%
+}
+\long\def\HyReturnAfterFi#1\fi{\fi#1}
+
+% #1 is a control sequence in which to do the replacements.
+\def\backslashparens#1{%
+  \xdef#1{#1}% redefine it as its expansion; the definition is simply
+             % \lastnode when called from \setref -> \pdfmkdest.
+  \HyPsdSubst{(}{\realbackslash(}{#1}%
+  \HyPsdSubst{)}{\realbackslash)}{#1}%
+}
+
+\ifpdf
+  \input pdfcolor
+  \pdfcatalog{/PageMode /UseOutlines}%
+  % #1 is image name, #2 width (might be empty/whitespace), #3 height (ditto).
+  \def\dopdfimage#1#2#3{%
+    \def\imagewidth{#2}\setbox0 = \hbox{\ignorespaces #2}%
+    \def\imageheight{#3}\setbox2 = \hbox{\ignorespaces #3}%
+    % without \immediate, pdftex seg faults when the same image is
+    % included twice.  (Version 3.14159-pre-1.0-unofficial-20010704.)
+    \ifnum\pdftexversion < 14
+      \immediate\pdfimage
+    \else
+      \immediate\pdfximage
+    \fi
+      \ifdim \wd0 >0pt width \imagewidth \fi
+      \ifdim \wd2 >0pt height \imageheight \fi
+      \ifnum\pdftexversion<13
+         #1.pdf%
+       \else
+         {#1.pdf}%
+       \fi
+    \ifnum\pdftexversion < 14 \else
+      \pdfrefximage \pdflastximage
+    \fi}
+  \def\pdfmkdest#1{{%
+    % We have to set dummies so commands such as @code, and characters
+    % such as \, aren't expanded when present in a section title.
+    \atdummies
+    \activebackslashdouble
+    \def\pdfdestname{#1}%
+    \backslashparens\pdfdestname
+    \pdfdest name{\pdfdestname} xyz%
+  }}%
+  %
+  % used to mark target names; must be expandable.
+  \def\pdfmkpgn#1{#1}%
+  %
+  \let\linkcolor = \Blue  % was Cyan, but that seems light?
+  \def\endlink{\Black\pdfendlink}
+  % Adding outlines to PDF; macros for calculating structure of outlines
+  % come from Petr Olsak
+  \def\expnumber#1{\expandafter\ifx\csname#1\endcsname\relax 0%
+    \else \csname#1\endcsname \fi}
+  \def\advancenumber#1{\tempnum=\expnumber{#1}\relax
+    \advance\tempnum by 1
+    \expandafter\xdef\csname#1\endcsname{\the\tempnum}}
+  %
+  % #1 is the section text, which is what will be displayed in the
+  % outline by the pdf viewer.  #2 is the pdf expression for the number
+  % of subentries (or empty, for subsubsections).  #3 is the node text,
+  % which might be empty if this toc entry had no corresponding node.
+  % #4 is the page number
+  %
+  \def\dopdfoutline#1#2#3#4{%
+    % Generate a link to the node text if that exists; else, use the
+    % page number.  We could generate a destination for the section
+    % text in the case where a section has no node, but it doesn't
+    % seem worth the trouble, since most documents are normally structured.
+    \def\pdfoutlinedest{#3}%
+    \ifx\pdfoutlinedest\empty
+      \def\pdfoutlinedest{#4}%
+    \else
+      % Doubled backslashes in the name.
+      {\activebackslashdouble \xdef\pdfoutlinedest{#3}%
+       \backslashparens\pdfoutlinedest}%
+    \fi
+    %
+    % Also double the backslashes in the display string.
+    {\activebackslashdouble \xdef\pdfoutlinetext{#1}%
+     \backslashparens\pdfoutlinetext}%
+    %
+    \pdfoutline goto name{\pdfmkpgn{\pdfoutlinedest}}#2{\pdfoutlinetext}%
+  }
+  %
+  \def\pdfmakeoutlines{%
+    \begingroup
+      % Thanh's hack / proper braces in bookmarks
+      \edef\mylbrace{\iftrue \string{\else}\fi}\let\{=\mylbrace
+      \edef\myrbrace{\iffalse{\else\string}\fi}\let\}=\myrbrace
+      %
+      % Read toc silently, to get counts of subentries for \pdfoutline.
+      \def\numchapentry##1##2##3##4{%
+	\def\thischapnum{##2}%
+	\def\thissecnum{0}%
+	\def\thissubsecnum{0}%
+      }%
+      \def\numsecentry##1##2##3##4{%
+	\advancenumber{chap\thischapnum}%
+	\def\thissecnum{##2}%
+	\def\thissubsecnum{0}%
+      }%
+      \def\numsubsecentry##1##2##3##4{%
+	\advancenumber{sec\thissecnum}%
+	\def\thissubsecnum{##2}%
+      }%
+      \def\numsubsubsecentry##1##2##3##4{%
+	\advancenumber{subsec\thissubsecnum}%
+      }%
+      \def\thischapnum{0}%
+      \def\thissecnum{0}%
+      \def\thissubsecnum{0}%
+      %
+      % use \def rather than \let here because we redefine \chapentry et
+      % al. a second time, below.
+      \def\appentry{\numchapentry}%
+      \def\appsecentry{\numsecentry}%
+      \def\appsubsecentry{\numsubsecentry}%
+      \def\appsubsubsecentry{\numsubsubsecentry}%
+      \def\unnchapentry{\numchapentry}%
+      \def\unnsecentry{\numsecentry}%
+      \def\unnsubsecentry{\numsubsecentry}%
+      \def\unnsubsubsecentry{\numsubsubsecentry}%
+      \readdatafile{toc}%
+      %
+      % Read toc second time, this time actually producing the outlines.
+      % The `-' means take the \expnumber as the absolute number of
+      % subentries, which we calculated on our first read of the .toc above.
+      %
+      % We use the node names as the destinations.
+      \def\numchapentry##1##2##3##4{%
+        \dopdfoutline{##1}{count-\expnumber{chap##2}}{##3}{##4}}%
+      \def\numsecentry##1##2##3##4{%
+        \dopdfoutline{##1}{count-\expnumber{sec##2}}{##3}{##4}}%
+      \def\numsubsecentry##1##2##3##4{%
+        \dopdfoutline{##1}{count-\expnumber{subsec##2}}{##3}{##4}}%
+      \def\numsubsubsecentry##1##2##3##4{% count is always zero
+        \dopdfoutline{##1}{}{##3}{##4}}%
+      %
+      % PDF outlines are displayed using system fonts, instead of
+      % document fonts.  Therefore we cannot use special characters,
+      % since the encoding is unknown.  For example, the eogonek from
+      % Latin 2 (0xea) gets translated to a | character.  Info from
+      % Staszek Wawrykiewicz, 19 Jan 2004 04:09:24 +0100.
+      %
+      % xx to do this right, we have to translate 8-bit characters to
+      % their "best" equivalent, based on the @documentencoding.  Right
+      % now, I guess we'll just let the pdf reader have its way.
+      \indexnofonts
+      \setupdatafile
+      \catcode`\\=\active \otherbackslash
+      \input \jobname.toc
+    \endgroup
+  }
+  %
+  \def\skipspaces#1{\def\PP{#1}\def\D{|}%
+    \ifx\PP\D\let\nextsp\relax
+    \else\let\nextsp\skipspaces
+      \ifx\p\space\else\addtokens{\filename}{\PP}%
+        \advance\filenamelength by 1
+      \fi
+    \fi
+    \nextsp}
+  \def\getfilename#1{\filenamelength=0\expandafter\skipspaces#1|\relax}
+  \ifnum\pdftexversion < 14
+    \let \startlink \pdfannotlink
+  \else
+    \let \startlink \pdfstartlink
+  \fi
+  % make a live url in pdf output.
+  \def\pdfurl#1{%
+    \begingroup
+      % it seems we really need yet another set of dummies; have not
+      % tried to figure out what each command should do in the context
+      % of @url.  for now, just make @/ a no-op, that's the only one
+      % people have actually reported a problem with.
+      % 
+      \normalturnoffactive
+      \def\@{@}%
+      \let\/=\empty
+      \makevalueexpandable
+      \leavevmode\Red
+      \startlink attr{/Border [0 0 0]}%
+        user{/Subtype /Link /A << /S /URI /URI (#1) >>}%
+    \endgroup}
+  \def\pdfgettoks#1.{\setbox\boxA=\hbox{\toksA={#1.}\toksB={}\maketoks}}
+  \def\addtokens#1#2{\edef\addtoks{\noexpand#1={\the#1#2}}\addtoks}
+  \def\adn#1{\addtokens{\toksC}{#1}\global\countA=1\let\next=\maketoks}
+  \def\poptoks#1#2|ENDTOKS|{\let\first=#1\toksD={#1}\toksA={#2}}
+  \def\maketoks{%
+    \expandafter\poptoks\the\toksA|ENDTOKS|\relax
+    \ifx\first0\adn0
+    \else\ifx\first1\adn1 \else\ifx\first2\adn2 \else\ifx\first3\adn3
+    \else\ifx\first4\adn4 \else\ifx\first5\adn5 \else\ifx\first6\adn6
+    \else\ifx\first7\adn7 \else\ifx\first8\adn8 \else\ifx\first9\adn9
+    \else
+      \ifnum0=\countA\else\makelink\fi
+      \ifx\first.\let\next=\done\else
+        \let\next=\maketoks
+        \addtokens{\toksB}{\the\toksD}
+        \ifx\first,\addtokens{\toksB}{\space}\fi
+      \fi
+    \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi
+    \next}
+  \def\makelink{\addtokens{\toksB}%
+    {\noexpand\pdflink{\the\toksC}}\toksC={}\global\countA=0}
+  \def\pdflink#1{%
+    \startlink attr{/Border [0 0 0]} goto name{\pdfmkpgn{#1}}
+    \linkcolor #1\endlink}
+  \def\done{\edef\st{\global\noexpand\toksA={\the\toksB}}\st}
+\else
+  \let\pdfmkdest = \gobble
+  \let\pdfurl = \gobble
+  \let\endlink = \relax
+  \let\linkcolor = \relax
+  \let\pdfmakeoutlines = \relax
+\fi  % \ifx\pdfoutput
+
+
+\message{fonts,}
+
+% Change the current font style to #1, remembering it in \curfontstyle.
+% For now, we do not accumulate font styles: @b{@i{foo}} prints foo in
+% italics, not bold italics.
+%
+\def\setfontstyle#1{%
+  \def\curfontstyle{#1}% not as a control sequence, because we are \edef'd.
+  \csname ten#1\endcsname  % change the current font
+}
+
+% Select #1 fonts with the current style.
+%
+\def\selectfonts#1{\csname #1fonts\endcsname \csname\curfontstyle\endcsname}
+
+\def\rm{\fam=0 \setfontstyle{rm}}
+\def\it{\fam=\itfam \setfontstyle{it}}
+\def\sl{\fam=\slfam \setfontstyle{sl}}
+\def\bf{\fam=\bffam \setfontstyle{bf}}\def\bfstylename{bf}
+\def\tt{\fam=\ttfam \setfontstyle{tt}}
+
+% Texinfo sort of supports the sans serif font style, which plain TeX does not.
+% So we set up a \sf.
+\newfam\sffam
+\def\sf{\fam=\sffam \setfontstyle{sf}}
+\let\li = \sf % Sometimes we call it \li, not \sf.
+
+% We don't need math for this font style.
+\def\ttsl{\setfontstyle{ttsl}}
+
+
+% Default leading.
+\newdimen\textleading  \textleading = 13.2pt
+
+% Set the baselineskip to #1, and the lineskip and strut size
+% correspondingly.  There is no deep meaning behind these magic numbers
+% used as factors; they just match (closely enough) what Knuth defined.
+%
+\def\lineskipfactor{.08333}
+\def\strutheightpercent{.70833}
+\def\strutdepthpercent {.29167}
+%
+\def\setleading#1{%
+  \normalbaselineskip = #1\relax
+  \normallineskip = \lineskipfactor\normalbaselineskip
+  \normalbaselines
+  \setbox\strutbox =\hbox{%
+    \vrule width0pt height\strutheightpercent\baselineskip
+                    depth \strutdepthpercent \baselineskip
+  }%
+}
+
+
+% Set the font macro #1 to the font named #2, adding on the
+% specified font prefix (normally `cm').
+% #3 is the font's design size, #4 is a scale factor
+\def\setfont#1#2#3#4{\font#1=\fontprefix#2#3 scaled #4}
+
+
+% Use cm as the default font prefix.
+% To specify the font prefix, you must define \fontprefix
+% before you read in texinfo.tex.
+\ifx\fontprefix\undefined
+\def\fontprefix{cm}
+\fi
+% Support font families that don't use the same naming scheme as CM.
+\def\rmshape{r}
+\def\rmbshape{bx}               %where the normal face is bold
+\def\bfshape{b}
+\def\bxshape{bx}
+\def\ttshape{tt}
+\def\ttbshape{tt}
+\def\ttslshape{sltt}
+\def\itshape{ti}
+\def\itbshape{bxti}
+\def\slshape{sl}
+\def\slbshape{bxsl}
+\def\sfshape{ss}
+\def\sfbshape{ss}
+\def\scshape{csc}
+\def\scbshape{csc}
+
+% Definitions for a main text size of 11pt.  This is the default in
+% Texinfo.
+% 
+\def\definetextfontsizexi{
+% Text fonts (11.2pt, magstep1).
+\def\textnominalsize{11pt}
+\edef\mainmagstep{\magstephalf}
+\setfont\textrm\rmshape{10}{\mainmagstep}
+\setfont\texttt\ttshape{10}{\mainmagstep}
+\setfont\textbf\bfshape{10}{\mainmagstep}
+\setfont\textit\itshape{10}{\mainmagstep}
+\setfont\textsl\slshape{10}{\mainmagstep}
+\setfont\textsf\sfshape{10}{\mainmagstep}
+\setfont\textsc\scshape{10}{\mainmagstep}
+\setfont\textttsl\ttslshape{10}{\mainmagstep}
+\font\texti=cmmi10 scaled \mainmagstep
+\font\textsy=cmsy10 scaled \mainmagstep
+
+% A few fonts for @defun names and args.
+\setfont\defbf\bfshape{10}{\magstep1}
+\setfont\deftt\ttshape{10}{\magstep1}
+\setfont\defttsl\ttslshape{10}{\magstep1}
+\def\df{\let\tentt=\deftt \let\tenbf = \defbf \let\tenttsl=\defttsl \bf}
+
+% Fonts for indices, footnotes, small examples (9pt).
+\def\smallnominalsize{9pt}
+\setfont\smallrm\rmshape{9}{1000}
+\setfont\smalltt\ttshape{9}{1000}
+\setfont\smallbf\bfshape{10}{900}
+\setfont\smallit\itshape{9}{1000}
+\setfont\smallsl\slshape{9}{1000}
+\setfont\smallsf\sfshape{9}{1000}
+\setfont\smallsc\scshape{10}{900}
+\setfont\smallttsl\ttslshape{10}{900}
+\font\smalli=cmmi9
+\font\smallsy=cmsy9
+
+% Fonts for small examples (8pt).
+\def\smallernominalsize{8pt}
+\setfont\smallerrm\rmshape{8}{1000}
+\setfont\smallertt\ttshape{8}{1000}
+\setfont\smallerbf\bfshape{10}{800}
+\setfont\smallerit\itshape{8}{1000}
+\setfont\smallersl\slshape{8}{1000}
+\setfont\smallersf\sfshape{8}{1000}
+\setfont\smallersc\scshape{10}{800}
+\setfont\smallerttsl\ttslshape{10}{800}
+\font\smalleri=cmmi8
+\font\smallersy=cmsy8
+
+% Fonts for title page (20.4pt):
+\def\titlenominalsize{20pt}
+\setfont\titlerm\rmbshape{12}{\magstep3}
+\setfont\titleit\itbshape{10}{\magstep4}
+\setfont\titlesl\slbshape{10}{\magstep4}
+\setfont\titlett\ttbshape{12}{\magstep3}
+\setfont\titlettsl\ttslshape{10}{\magstep4}
+\setfont\titlesf\sfbshape{17}{\magstep1}
+\let\titlebf=\titlerm
+\setfont\titlesc\scbshape{10}{\magstep4}
+\font\titlei=cmmi12 scaled \magstep3
+\font\titlesy=cmsy10 scaled \magstep4
+\def\authorrm{\secrm}
+\def\authortt{\sectt}
+
+% Chapter (and unnumbered) fonts (17.28pt).
+\def\chapnominalsize{17pt}
+\setfont\chaprm\rmbshape{12}{\magstep2}
+\setfont\chapit\itbshape{10}{\magstep3}
+\setfont\chapsl\slbshape{10}{\magstep3}
+\setfont\chaptt\ttbshape{12}{\magstep2}
+\setfont\chapttsl\ttslshape{10}{\magstep3}
+\setfont\chapsf\sfbshape{17}{1000}
+\let\chapbf=\chaprm
+\setfont\chapsc\scbshape{10}{\magstep3}
+\font\chapi=cmmi12 scaled \magstep2
+\font\chapsy=cmsy10 scaled \magstep3
+
+% Section fonts (14.4pt).
+\def\secnominalsize{14pt}
+\setfont\secrm\rmbshape{12}{\magstep1}
+\setfont\secit\itbshape{10}{\magstep2}
+\setfont\secsl\slbshape{10}{\magstep2}
+\setfont\sectt\ttbshape{12}{\magstep1}
+\setfont\secttsl\ttslshape{10}{\magstep2}
+\setfont\secsf\sfbshape{12}{\magstep1}
+\let\secbf\secrm
+\setfont\secsc\scbshape{10}{\magstep2}
+\font\seci=cmmi12 scaled \magstep1
+\font\secsy=cmsy10 scaled \magstep2
+
+% Subsection fonts (13.15pt).
+\def\ssecnominalsize{13pt}
+\setfont\ssecrm\rmbshape{12}{\magstephalf}
+\setfont\ssecit\itbshape{10}{1315}
+\setfont\ssecsl\slbshape{10}{1315}
+\setfont\ssectt\ttbshape{12}{\magstephalf}
+\setfont\ssecttsl\ttslshape{10}{1315}
+\setfont\ssecsf\sfbshape{12}{\magstephalf}
+\let\ssecbf\ssecrm
+\setfont\ssecsc\scbshape{10}{1315}
+\font\sseci=cmmi12 scaled \magstephalf
+\font\ssecsy=cmsy10 scaled 1315
+
+% Reduced fonts for @acro in text (10pt).
+\def\reducednominalsize{10pt}
+\setfont\reducedrm\rmshape{10}{1000}
+\setfont\reducedtt\ttshape{10}{1000}
+\setfont\reducedbf\bfshape{10}{1000}
+\setfont\reducedit\itshape{10}{1000}
+\setfont\reducedsl\slshape{10}{1000}
+\setfont\reducedsf\sfshape{10}{1000}
+\setfont\reducedsc\scshape{10}{1000}
+\setfont\reducedttsl\ttslshape{10}{1000}
+\font\reducedi=cmmi10
+\font\reducedsy=cmsy10
+
+% reset the current fonts
+\textfonts
+\rm
+} % end of 11pt text font size definitions
+
+
+% Definitions to make the main text be 10pt Computer Modern, with
+% section, chapter, etc., sizes following suit.  This is for the GNU
+% Press printing of the Emacs 22 manual.  Maybe other manuals in the
+% future.  Used with @smallbook, which sets the leading to 12pt.
+% 
+\def\definetextfontsizex{%
+% Text fonts (10pt).
+\def\textnominalsize{10pt}
+\edef\mainmagstep{1000}
+\setfont\textrm\rmshape{10}{\mainmagstep}
+\setfont\texttt\ttshape{10}{\mainmagstep}
+\setfont\textbf\bfshape{10}{\mainmagstep}
+\setfont\textit\itshape{10}{\mainmagstep}
+\setfont\textsl\slshape{10}{\mainmagstep}
+\setfont\textsf\sfshape{10}{\mainmagstep}
+\setfont\textsc\scshape{10}{\mainmagstep}
+\setfont\textttsl\ttslshape{10}{\mainmagstep}
+\font\texti=cmmi10 scaled \mainmagstep
+\font\textsy=cmsy10 scaled \mainmagstep
+
+% A few fonts for @defun names and args.
+\setfont\defbf\bfshape{10}{\magstephalf}
+\setfont\deftt\ttshape{10}{\magstephalf}
+\setfont\defttsl\ttslshape{10}{\magstephalf}
+\def\df{\let\tentt=\deftt \let\tenbf = \defbf \let\tenttsl=\defttsl \bf}
+
+% Fonts for indices, footnotes, small examples (9pt).
+\def\smallnominalsize{9pt}
+\setfont\smallrm\rmshape{9}{1000}
+\setfont\smalltt\ttshape{9}{1000}
+\setfont\smallbf\bfshape{10}{900}
+\setfont\smallit\itshape{9}{1000}
+\setfont\smallsl\slshape{9}{1000}
+\setfont\smallsf\sfshape{9}{1000}
+\setfont\smallsc\scshape{10}{900}
+\setfont\smallttsl\ttslshape{10}{900}
+\font\smalli=cmmi9
+\font\smallsy=cmsy9
+
+% Fonts for small examples (8pt).
+\def\smallernominalsize{8pt}
+\setfont\smallerrm\rmshape{8}{1000}
+\setfont\smallertt\ttshape{8}{1000}
+\setfont\smallerbf\bfshape{10}{800}
+\setfont\smallerit\itshape{8}{1000}
+\setfont\smallersl\slshape{8}{1000}
+\setfont\smallersf\sfshape{8}{1000}
+\setfont\smallersc\scshape{10}{800}
+\setfont\smallerttsl\ttslshape{10}{800}
+\font\smalleri=cmmi8
+\font\smallersy=cmsy8
+
+% Fonts for title page (20.4pt):
+\def\titlenominalsize{20pt}
+\setfont\titlerm\rmbshape{12}{\magstep3}
+\setfont\titleit\itbshape{10}{\magstep4}
+\setfont\titlesl\slbshape{10}{\magstep4}
+\setfont\titlett\ttbshape{12}{\magstep3}
+\setfont\titlettsl\ttslshape{10}{\magstep4}
+\setfont\titlesf\sfbshape{17}{\magstep1}
+\let\titlebf=\titlerm
+\setfont\titlesc\scbshape{10}{\magstep4}
+\font\titlei=cmmi12 scaled \magstep3
+\font\titlesy=cmsy10 scaled \magstep4
+\def\authorrm{\secrm}
+\def\authortt{\sectt}
+
+% Chapter fonts (14.4pt).
+\def\chapnominalsize{14pt}
+\setfont\chaprm\rmbshape{12}{\magstep1}
+\setfont\chapit\itbshape{10}{\magstep2}
+\setfont\chapsl\slbshape{10}{\magstep2}
+\setfont\chaptt\ttbshape{12}{\magstep1}
+\setfont\chapttsl\ttslshape{10}{\magstep2}
+\setfont\chapsf\sfbshape{12}{\magstep1}
+\let\chapbf\chaprm
+\setfont\chapsc\scbshape{10}{\magstep2}
+\font\chapi=cmmi12 scaled \magstep1
+\font\chapsy=cmsy10 scaled \magstep2
+
+% Section fonts (12pt).
+\def\secnominalsize{12pt}
+\setfont\secrm\rmbshape{12}{1000}
+\setfont\secit\itbshape{10}{\magstep1}
+\setfont\secsl\slbshape{10}{\magstep1}
+\setfont\sectt\ttbshape{12}{1000}
+\setfont\secttsl\ttslshape{10}{\magstep1}
+\setfont\secsf\sfbshape{12}{1000}
+\let\secbf\secrm
+\setfont\secsc\scbshape{10}{\magstep1}
+\font\seci=cmmi12 
+\font\secsy=cmsy10 scaled \magstep1
+
+% Subsection fonts (10pt).
+\def\ssecnominalsize{10pt}
+\setfont\ssecrm\rmbshape{10}{1000}
+\setfont\ssecit\itbshape{10}{1000}
+\setfont\ssecsl\slbshape{10}{1000}
+\setfont\ssectt\ttbshape{10}{1000}
+\setfont\ssecttsl\ttslshape{10}{1000}
+\setfont\ssecsf\sfbshape{10}{1000}
+\let\ssecbf\ssecrm
+\setfont\ssecsc\scbshape{10}{1000}
+\font\sseci=cmmi10
+\font\ssecsy=cmsy10
+
+% Reduced fonts for @acro in text (9pt).
+\def\reducednominalsize{9pt}
+\setfont\reducedrm\rmshape{9}{1000}
+\setfont\reducedtt\ttshape{9}{1000}
+\setfont\reducedbf\bfshape{10}{900}
+\setfont\reducedit\itshape{9}{1000}
+\setfont\reducedsl\slshape{9}{1000}
+\setfont\reducedsf\sfshape{9}{1000}
+\setfont\reducedsc\scshape{10}{900}
+\setfont\reducedttsl\ttslshape{10}{900}
+\font\reducedi=cmmi9
+\font\reducedsy=cmsy9
+
+% reduce space between paragraphs
+\divide\parskip by 2
+
+% reset the current fonts
+\textfonts
+\rm
+} % end of 10pt text font size definitions
+
+
+% We provide the user-level command
+%   @fonttextsize 10
+% (or 11) to redefine the text font size.  pt is assumed.
+% 
+\def\xword{10}
+\def\xiword{11}
+%
+\parseargdef\fonttextsize{%
+  \def\textsizearg{#1}%
+  \wlog{doing @fonttextsize \textsizearg}%
+  %
+  % Set \globaldefs so that documents can use this inside @tex, since
+  % makeinfo 4.8 does not support it, but we need it nonetheless.
+  % 
+ \begingroup \globaldefs=1
+  \ifx\textsizearg\xword \definetextfontsizex
+  \else \ifx\textsizearg\xiword \definetextfontsizexi
+  \else
+    \errhelp=\EMsimple
+    \errmessage{@fonttextsize only supports `10' or `11', not `\textsizearg'}
+  \fi\fi
+ \endgroup
+}
+
+
+% In order for the font changes to affect most math symbols and letters,
+% we have to define the \textfont of the standard families.  Since
+% texinfo doesn't allow for producing subscripts and superscripts except
+% in the main text, we don't bother to reset \scriptfont and
+% \scriptscriptfont (which would also require loading a lot more fonts).
+%
+\def\resetmathfonts{%
+  \textfont0=\tenrm \textfont1=\teni \textfont2=\tensy
+  \textfont\itfam=\tenit \textfont\slfam=\tensl \textfont\bffam=\tenbf
+  \textfont\ttfam=\tentt \textfont\sffam=\tensf
+}
+
+% The font-changing commands redefine the meanings of \tenSTYLE, instead
+% of just \STYLE.  We do this because \STYLE needs to also set the
+% current \fam for math mode.  Our \STYLE (e.g., \rm) commands hardwire
+% \tenSTYLE to set the current font.
+%
+% Each font-changing command also sets the names \lsize (one size lower)
+% and \lllsize (three sizes lower).  These relative commands are used in
+% the LaTeX logo and acronyms.
+%
+% This all needs generalizing, badly.
+%
+\def\textfonts{%
+  \let\tenrm=\textrm \let\tenit=\textit \let\tensl=\textsl
+  \let\tenbf=\textbf \let\tentt=\texttt \let\smallcaps=\textsc
+  \let\tensf=\textsf \let\teni=\texti \let\tensy=\textsy
+  \let\tenttsl=\textttsl
+  \def\curfontsize{text}%
+  \def\lsize{reduced}\def\lllsize{smaller}%
+  \resetmathfonts \setleading{\textleading}}
+\def\titlefonts{%
+  \let\tenrm=\titlerm \let\tenit=\titleit \let\tensl=\titlesl
+  \let\tenbf=\titlebf \let\tentt=\titlett \let\smallcaps=\titlesc
+  \let\tensf=\titlesf \let\teni=\titlei \let\tensy=\titlesy
+  \let\tenttsl=\titlettsl
+  \def\curfontsize{title}%
+  \def\lsize{chap}\def\lllsize{subsec}%
+  \resetmathfonts \setleading{25pt}}
+\def\titlefont#1{{\titlefonts\rm #1}}
+\def\chapfonts{%
+  \let\tenrm=\chaprm \let\tenit=\chapit \let\tensl=\chapsl
+  \let\tenbf=\chapbf \let\tentt=\chaptt \let\smallcaps=\chapsc
+  \let\tensf=\chapsf \let\teni=\chapi \let\tensy=\chapsy
+  \let\tenttsl=\chapttsl
+  \def\curfontsize{chap}%
+  \def\lsize{sec}\def\lllsize{text}%
+  \resetmathfonts \setleading{19pt}}
+\def\secfonts{%
+  \let\tenrm=\secrm \let\tenit=\secit \let\tensl=\secsl
+  \let\tenbf=\secbf \let\tentt=\sectt \let\smallcaps=\secsc
+  \let\tensf=\secsf \let\teni=\seci \let\tensy=\secsy
+  \let\tenttsl=\secttsl
+  \def\curfontsize{sec}%
+  \def\lsize{subsec}\def\lllsize{reduced}%
+  \resetmathfonts \setleading{16pt}}
+\def\subsecfonts{%
+  \let\tenrm=\ssecrm \let\tenit=\ssecit \let\tensl=\ssecsl
+  \let\tenbf=\ssecbf \let\tentt=\ssectt \let\smallcaps=\ssecsc
+  \let\tensf=\ssecsf \let\teni=\sseci \let\tensy=\ssecsy
+  \let\tenttsl=\ssecttsl
+  \def\curfontsize{ssec}%
+  \def\lsize{text}\def\lllsize{small}%
+  \resetmathfonts \setleading{15pt}}
+\let\subsubsecfonts = \subsecfonts
+\def\reducedfonts{%
+  \let\tenrm=\reducedrm \let\tenit=\reducedit \let\tensl=\reducedsl
+  \let\tenbf=\reducedbf \let\tentt=\reducedtt \let\reducedcaps=\reducedsc
+  \let\tensf=\reducedsf \let\teni=\reducedi \let\tensy=\reducedsy
+  \let\tenttsl=\reducedttsl
+  \def\curfontsize{reduced}%
+  \def\lsize{small}\def\lllsize{smaller}%
+  \resetmathfonts \setleading{10.5pt}}
+\def\smallfonts{%
+  \let\tenrm=\smallrm \let\tenit=\smallit \let\tensl=\smallsl
+  \let\tenbf=\smallbf \let\tentt=\smalltt \let\smallcaps=\smallsc
+  \let\tensf=\smallsf \let\teni=\smalli \let\tensy=\smallsy
+  \let\tenttsl=\smallttsl
+  \def\curfontsize{small}%
+  \def\lsize{smaller}\def\lllsize{smaller}%
+  \resetmathfonts \setleading{10.5pt}}
+\def\smallerfonts{%
+  \let\tenrm=\smallerrm \let\tenit=\smallerit \let\tensl=\smallersl
+  \let\tenbf=\smallerbf \let\tentt=\smallertt \let\smallcaps=\smallersc
+  \let\tensf=\smallersf \let\teni=\smalleri \let\tensy=\smallersy
+  \let\tenttsl=\smallerttsl
+  \def\curfontsize{smaller}%
+  \def\lsize{smaller}\def\lllsize{smaller}%
+  \resetmathfonts \setleading{9.5pt}}
+
+% Set the fonts to use with the @small... environments.
+\let\smallexamplefonts = \smallfonts
+
+% About \smallexamplefonts.  If we use \smallfonts (9pt), @smallexample
+% can fit this many characters:
+%   8.5x11=86   smallbook=72  a4=90  a5=69
+% If we use \scriptfonts (8pt), then we can fit this many characters:
+%   8.5x11=90+  smallbook=80  a4=90+  a5=77
+% For me, subjectively, the few extra characters that fit aren't worth
+% the additional smallness of 8pt.  So I'm making the default 9pt.
+%
+% By the way, for comparison, here's what fits with @example (10pt):
+%   8.5x11=71  smallbook=60  a4=75  a5=58
+%
+% I wish the USA used A4 paper.
+% --karl, 24jan03.
+
+
+% Set up the default fonts, so we can use them for creating boxes.
+%
+\definetextfontsizexi
+
+% Define these so they can be easily changed for other fonts.
+\def\angleleft{$\langle$}
+\def\angleright{$\rangle$}
+
+% Count depth in font-changes, for error checks
+\newcount\fontdepth \fontdepth=0
+
+% Fonts for short table of contents.
+\setfont\shortcontrm\rmshape{12}{1000}
+\setfont\shortcontbf\bfshape{10}{\magstep1}  % no cmb12
+\setfont\shortcontsl\slshape{12}{1000}
+\setfont\shortconttt\ttshape{12}{1000}
+
+%% Add scribe-like font environments, plus @l for inline lisp (usually sans
+%% serif) and @ii for TeX italic
+
+% \smartitalic{ARG} outputs arg in italics, followed by an italic correction
+% unless the following character is such as not to need one.
+\def\smartitalicx{\ifx\next,\else\ifx\next-\else\ifx\next.\else
+                    \ptexslash\fi\fi\fi}
+\def\smartslanted#1{{\ifusingtt\ttsl\sl #1}\futurelet\next\smartitalicx}
+\def\smartitalic#1{{\ifusingtt\ttsl\it #1}\futurelet\next\smartitalicx}
+
+% like \smartslanted except unconditionally uses \ttsl.
+% @var is set to this for defun arguments.
+\def\ttslanted#1{{\ttsl #1}\futurelet\next\smartitalicx}
+
+% like \smartslanted except unconditionally use \sl.  We never want
+% ttsl for book titles, do we?
+\def\cite#1{{\sl #1}\futurelet\next\smartitalicx}
+
+\let\i=\smartitalic
+\let\slanted=\smartslanted
+\let\var=\smartslanted
+\let\dfn=\smartslanted
+\let\emph=\smartitalic
+
+% @b, explicit bold.
+\def\b#1{{\bf #1}}
+\let\strong=\b
+
+% @sansserif, explicit sans.
+\def\sansserif#1{{\sf #1}}
+
+% We can't just use \exhyphenpenalty, because that only has effect at
+% the end of a paragraph.  Restore normal hyphenation at the end of the
+% group within which \nohyphenation is presumably called.
+%
+\def\nohyphenation{\hyphenchar\font = -1  \aftergroup\restorehyphenation}
+\def\restorehyphenation{\hyphenchar\font = `- }
+
+% Set sfcode to normal for the chars that usually have another value.
+% Can't use plain's \frenchspacing because it uses the `\x notation, and
+% sometimes \x has an active definition that messes things up.
+%
+\catcode`@=11
+  \def\plainfrenchspacing{%
+    \sfcode\dotChar  =\@m \sfcode\questChar=\@m \sfcode\exclamChar=\@m
+    \sfcode\colonChar=\@m \sfcode\semiChar =\@m \sfcode\commaChar =\@m
+    \def\endofsentencespacefactor{1000}% for @. and friends
+  }
+  \def\plainnonfrenchspacing{%
+    \sfcode`\.3000\sfcode`\?3000\sfcode`\!3000
+    \sfcode`\:2000\sfcode`\;1500\sfcode`\,1250
+    \def\endofsentencespacefactor{3000}% for @. and friends
+  }
+\catcode`@=\other
+\def\endofsentencespacefactor{3000}% default
+
+\def\t#1{%
+  {\tt \rawbackslash \plainfrenchspacing #1}%
+  \null
+}
+\def\samp#1{`\tclose{#1}'\null}
+\setfont\keyrm\rmshape{8}{1000}
+\font\keysy=cmsy9
+\def\key#1{{\keyrm\textfont2=\keysy \leavevmode\hbox{%
+  \raise0.4pt\hbox{\angleleft}\kern-.08em\vtop{%
+    \vbox{\hrule\kern-0.4pt
+     \hbox{\raise0.4pt\hbox{\vphantom{\angleleft}}#1}}%
+    \kern-0.4pt\hrule}%
+  \kern-.06em\raise0.4pt\hbox{\angleright}}}}
+\def\key #1{{\nohyphenation \uppercase{#1}}\null}
+% The old definition, with no lozenge:
+%\def\key #1{{\ttsl \nohyphenation \uppercase{#1}}\null}
+\def\ctrl #1{{\tt \rawbackslash \hat}#1}
+
+% @file, @option are the same as @samp.
+\let\file=\samp
+\let\option=\samp
+
+% @code is a modification of @t,
+% which makes spaces the same size as normal in the surrounding text.
+\def\tclose#1{%
+  {%
+    % Change normal interword space to be same as for the current font.
+    \spaceskip = \fontdimen2\font
+    %
+    % Switch to typewriter.
+    \tt
+    %
+    % But `\ ' produces the large typewriter interword space.
+    \def\ {{\spaceskip = 0pt{} }}%
+    %
+    % Turn off hyphenation.
+    \nohyphenation
+    %
+    \rawbackslash
+    \plainfrenchspacing
+    #1%
+  }%
+  \null
+}
+
+% We *must* turn on hyphenation at `-' and `_' in @code.
+% Otherwise, it is too hard to avoid overfull hboxes
+% in the Emacs manual, the Library manual, etc.
+
+% Unfortunately, TeX uses one parameter (\hyphenchar) to control
+% both hyphenation at - and hyphenation within words.
+% We must therefore turn them both off (\tclose does that)
+% and arrange explicitly to hyphenate at a dash.
+%  -- rms.
+{
+  \catcode`\-=\active \catcode`\_=\active
+  \catcode`\'=\active \catcode`\`=\active
+  %
+  \global\def\code{\begingroup
+    \catcode\rquoteChar=\active \catcode\lquoteChar=\active
+    \let'\codequoteright \let`\codequoteleft
+    %
+    \catcode\dashChar=\active  \catcode\underChar=\active
+    \ifallowcodebreaks
+     \let-\codedash
+     \let_\codeunder
+    \else
+     \let-\realdash
+     \let_\realunder
+    \fi
+    \codex
+  }
+}
+
+\def\realdash{-}
+\def\codedash{-\discretionary{}{}{}}
+\def\codeunder{%
+  % this is all so @math{@code{var_name}+1} can work.  In math mode, _
+  % is "active" (mathcode"8000) and \normalunderscore (or \char95, etc.)
+  % will therefore expand the active definition of _, which is us
+  % (inside @code that is), therefore an endless loop.
+  \ifusingtt{\ifmmode
+               \mathchar"075F % class 0=ordinary, family 7=ttfam, pos 0x5F=_.
+             \else\normalunderscore \fi
+             \discretionary{}{}{}}%
+            {\_}%
+}
+\def\codex #1{\tclose{#1}\endgroup}
+
+% An additional complication: the above will allow breaks after, e.g.,
+% each of the four underscores in __typeof__.  This is undesirable in
+% some manuals, especially if they don't have long identifiers in
+% general.  @allowcodebreaks provides a way to control this.
+% 
+\newif\ifallowcodebreaks  \allowcodebreakstrue
+
+\def\keywordtrue{true}
+\def\keywordfalse{false}
+
+\parseargdef\allowcodebreaks{%
+  \def\txiarg{#1}%
+  \ifx\txiarg\keywordtrue
+    \allowcodebreakstrue
+  \else\ifx\txiarg\keywordfalse
+    \allowcodebreaksfalse
+  \else
+    \errhelp = \EMsimple
+    \errmessage{Unknown @allowcodebreaks option `\txiarg'}%
+  \fi\fi
+}
+
+% @kbd is like @code, except that if the argument is just one @key command,
+% then @kbd has no effect.
+
+% @kbdinputstyle -- arg is `distinct' (@kbd uses slanted tty font always),
+%   `example' (@kbd uses ttsl only inside of @example and friends),
+%   or `code' (@kbd uses normal tty font always).
+\parseargdef\kbdinputstyle{%
+  \def\txiarg{#1}%
+  \ifx\txiarg\worddistinct
+    \gdef\kbdexamplefont{\ttsl}\gdef\kbdfont{\ttsl}%
+  \else\ifx\txiarg\wordexample
+    \gdef\kbdexamplefont{\ttsl}\gdef\kbdfont{\tt}%
+  \else\ifx\txiarg\wordcode
+    \gdef\kbdexamplefont{\tt}\gdef\kbdfont{\tt}%
+  \else
+    \errhelp = \EMsimple
+    \errmessage{Unknown @kbdinputstyle option `\txiarg'}%
+  \fi\fi\fi
+}
+\def\worddistinct{distinct}
+\def\wordexample{example}
+\def\wordcode{code}
+
+% Default is `distinct.'
+\kbdinputstyle distinct
+
+\def\xkey{\key}
+\def\kbdfoo#1#2#3\par{\def\one{#1}\def\three{#3}\def\threex{??}%
+\ifx\one\xkey\ifx\threex\three \key{#2}%
+\else{\tclose{\kbdfont\look}}\fi
+\else{\tclose{\kbdfont\look}}\fi}
+
+% For @indicateurl, @env, @command quotes seem unnecessary, so use \code.
+\let\indicateurl=\code
+\let\env=\code
+\let\command=\code
+
+% @uref (abbreviation for `urlref') takes an optional (comma-separated)
+% second argument specifying the text to display and an optional third
+% arg as text to display instead of (rather than in addition to) the url
+% itself.  First (mandatory) arg is the url.  Perhaps eventually put in
+% a hypertex \special here.
+%
+\def\uref#1{\douref #1,,,\finish}
+\def\douref#1,#2,#3,#4\finish{\begingroup
+  \unsepspaces
+  \pdfurl{#1}%
+  \setbox0 = \hbox{\ignorespaces #3}%
+  \ifdim\wd0 > 0pt
+    \unhbox0 % third arg given, show only that
+  \else
+    \setbox0 = \hbox{\ignorespaces #2}%
+    \ifdim\wd0 > 0pt
+      \ifpdf
+        \unhbox0             % PDF: 2nd arg given, show only it
+      \else
+        \unhbox0\ (\code{#1})% DVI: 2nd arg given, show both it and url
+      \fi
+    \else
+      \code{#1}% only url given, so show it
+    \fi
+  \fi
+  \endlink
+\endgroup}
+
+% @url synonym for @uref, since that's how everyone uses it.
+%
+\let\url=\uref
+
+% rms does not like angle brackets --karl, 17may97.
+% So now @email is just like @uref, unless we are pdf.
+%
+%\def\email#1{\angleleft{\tt #1}\angleright}
+\ifpdf
+  \def\email#1{\doemail#1,,\finish}
+  \def\doemail#1,#2,#3\finish{\begingroup
+    \unsepspaces
+    \pdfurl{mailto:#1}%
+    \setbox0 = \hbox{\ignorespaces #2}%
+    \ifdim\wd0>0pt\unhbox0\else\code{#1}\fi
+    \endlink
+  \endgroup}
+\else
+  \let\email=\uref
+\fi
+
+% Check if we are currently using a typewriter font.  Since all the
+% Computer Modern typewriter fonts have zero interword stretch (and
+% shrink), and it is reasonable to expect all typewriter fonts to have
+% this property, we can check that font parameter.
+%
+\def\ifmonospace{\ifdim\fontdimen3\font=0pt }
+
+% Typeset a dimension, e.g., `in' or `pt'.  The only reason for the
+% argument is to make the input look right: @dmn{pt} instead of @dmn{}pt.
+%
+\def\dmn#1{\thinspace #1}
+
+\def\kbd#1{\def\look{#1}\expandafter\kbdfoo\look??\par}
+
+% @l was never documented to mean ``switch to the Lisp font'',
+% and it is not used as such in any manual I can find.  We need it for
+% Polish suppressed-l.  --karl, 22sep96.
+%\def\l#1{{\li #1}\null}
+
+% Explicit font changes: @r, @sc, undocumented @ii.
+\def\r#1{{\rm #1}}              % roman font
+\def\sc#1{{\smallcaps#1}}       % smallcaps font
+\def\ii#1{{\it #1}}             % italic font
+
+% @acronym for "FBI", "NATO", and the like.
+% We print this one point size smaller, since it's intended for
+% all-uppercase.
+% 
+\def\acronym#1{\doacronym #1,,\finish}
+\def\doacronym#1,#2,#3\finish{%
+  {\selectfonts\lsize #1}%
+  \def\temp{#2}%
+  \ifx\temp\empty \else
+    \space ({\unsepspaces \ignorespaces \temp \unskip})%
+  \fi
+}
+
+% @abbr for "Comput. J." and the like.
+% No font change, but don't do end-of-sentence spacing.
+% 
+\def\abbr#1{\doabbr #1,,\finish}
+\def\doabbr#1,#2,#3\finish{%
+  {\plainfrenchspacing #1}%
+  \def\temp{#2}%
+  \ifx\temp\empty \else
+    \space ({\unsepspaces \ignorespaces \temp \unskip})%
+  \fi
+}
+
+% @pounds{} is a sterling sign, which Knuth put in the CM italic font.
+%
+\def\pounds{{\it\$}}
+
+% @euro{} comes from a separate font, depending on the current style.
+% We use the free feym* fonts from the eurosym package by Henrik
+% Theiling, which support regular, slanted, bold and bold slanted (and
+% "outlined" (blackboard board, sort of) versions, which we don't need).
+% It is available from http://www.ctan.org/tex-archive/fonts/eurosym.
+% 
+% Although only regular is the truly official Euro symbol, we ignore
+% that.  The Euro is designed to be slightly taller than the regular
+% font height.
+% 
+% feymr - regular
+% feymo - slanted
+% feybr - bold
+% feybo - bold slanted
+% 
+% There is no good (free) typewriter version, to my knowledge.
+% A feymr10 euro is ~7.3pt wide, while a normal cmtt10 char is ~5.25pt wide.
+% Hmm.
+% 
+% Also doesn't work in math.  Do we need to do math with euro symbols?
+% Hope not.
+% 
+% 
+\def\euro{{\eurofont e}}
+\def\eurofont{%
+  % We set the font at each command, rather than predefining it in
+  % \textfonts and the other font-switching commands, so that
+  % installations which never need the symbol don't have to have the
+  % font installed.
+  % 
+  % There is only one designed size (nominal 10pt), so we always scale
+  % that to the current nominal size.
+  % 
+  % By the way, simply using "at 1em" works for cmr10 and the like, but
+  % does not work for cmbx10 and other extended/shrunken fonts.
+  % 
+  \def\eurosize{\csname\curfontsize nominalsize\endcsname}%
+  %
+  \ifx\curfontstyle\bfstylename 
+    % bold:
+    \font\thiseurofont = \ifusingit{feybo10}{feybr10} at \eurosize
+  \else 
+    % regular:
+    \font\thiseurofont = \ifusingit{feymo10}{feymr10} at \eurosize
+  \fi
+  \thiseurofont
+}
+
+% @registeredsymbol - R in a circle.  The font for the R should really
+% be smaller yet, but lllsize is the best we can do for now.
+% Adapted from the plain.tex definition of \copyright.
+%
+\def\registeredsymbol{%
+  $^{{\ooalign{\hfil\raise.07ex\hbox{\selectfonts\lllsize R}%
+               \hfil\crcr\Orb}}%
+    }$%
+}
+
+% @textdegree - the normal degrees sign.
+%
+\def\textdegree{$^\circ$}
+
+% Laurent Siebenmann reports \Orb undefined with:
+%  Textures 1.7.7 (preloaded format=plain 93.10.14)  (68K)  16 APR 2004 02:38
+% so we'll define it if necessary.
+% 
+\ifx\Orb\undefined
+\def\Orb{\mathhexbox20D}
+\fi
+
+
+\message{page headings,}
+
+\newskip\titlepagetopglue \titlepagetopglue = 1.5in
+\newskip\titlepagebottomglue \titlepagebottomglue = 2pc
+
+% First the title page.  Must do @settitle before @titlepage.
+\newif\ifseenauthor
+\newif\iffinishedtitlepage
+
+% Do an implicit @contents or @shortcontents after @end titlepage if the
+% user says @setcontentsaftertitlepage or @setshortcontentsaftertitlepage.
+%
+\newif\ifsetcontentsaftertitlepage
+ \let\setcontentsaftertitlepage = \setcontentsaftertitlepagetrue
+\newif\ifsetshortcontentsaftertitlepage
+ \let\setshortcontentsaftertitlepage = \setshortcontentsaftertitlepagetrue
+
+\parseargdef\shorttitlepage{\begingroup\hbox{}\vskip 1.5in \chaprm \centerline{#1}%
+        \endgroup\page\hbox{}\page}
+
+\envdef\titlepage{%
+  % Open one extra group, as we want to close it in the middle of \Etitlepage.
+  \begingroup
+    \parindent=0pt \textfonts
+    % Leave some space at the very top of the page.
+    \vglue\titlepagetopglue
+    % No rule at page bottom unless we print one at the top with @title.
+    \finishedtitlepagetrue
+    %
+    % Most title ``pages'' are actually two pages long, with space
+    % at the top of the second.  We don't want the ragged left on the second.
+    \let\oldpage = \page
+    \def\page{%
+      \iffinishedtitlepage\else
+	 \finishtitlepage
+      \fi
+      \let\page = \oldpage
+      \page
+      \null
+    }%
+}
+
+\def\Etitlepage{%
+    \iffinishedtitlepage\else
+	\finishtitlepage
+    \fi
+    % It is important to do the page break before ending the group,
+    % because the headline and footline are only empty inside the group.
+    % If we use the new definition of \page, we always get a blank page
+    % after the title page, which we certainly don't want.
+    \oldpage
+  \endgroup
+  %
+  % Need this before the \...aftertitlepage checks so that if they are
+  % in effect the toc pages will come out with page numbers.
+  \HEADINGSon
+  %
+  % If they want short, they certainly want long too.
+  \ifsetshortcontentsaftertitlepage
+    \shortcontents
+    \contents
+    \global\let\shortcontents = \relax
+    \global\let\contents = \relax
+  \fi
+  %
+  \ifsetcontentsaftertitlepage
+    \contents
+    \global\let\contents = \relax
+    \global\let\shortcontents = \relax
+  \fi
+}
+
+\def\finishtitlepage{%
+  \vskip4pt \hrule height 2pt width \hsize
+  \vskip\titlepagebottomglue
+  \finishedtitlepagetrue
+}
+
+%%% Macros to be used within @titlepage:
+
+\let\subtitlerm=\tenrm
+\def\subtitlefont{\subtitlerm \normalbaselineskip = 13pt \normalbaselines}
+
+\def\authorfont{\authorrm \normalbaselineskip = 16pt \normalbaselines
+		\let\tt=\authortt}
+
+\parseargdef\title{%
+  \checkenv\titlepage
+  \leftline{\titlefonts\rm #1}
+  % print a rule at the page bottom also.
+  \finishedtitlepagefalse
+  \vskip4pt \hrule height 4pt width \hsize \vskip4pt
+}
+
+\parseargdef\subtitle{%
+  \checkenv\titlepage
+  {\subtitlefont \rightline{#1}}%
+}
+
+% @author should come last, but may come many times.
+% It can also be used inside @quotation.
+%
+\parseargdef\author{%
+  \def\temp{\quotation}%
+  \ifx\thisenv\temp
+    \def\quotationauthor{#1}% printed in \Equotation.
+  \else
+    \checkenv\titlepage
+    \ifseenauthor\else \vskip 0pt plus 1filll \seenauthortrue \fi
+    {\authorfont \leftline{#1}}%
+  \fi
+}
+
+
+%%% Set up page headings and footings.
+
+\let\thispage=\folio
+
+\newtoks\evenheadline    % headline on even pages
+\newtoks\oddheadline     % headline on odd pages
+\newtoks\evenfootline    % footline on even pages
+\newtoks\oddfootline     % footline on odd pages
+
+% Now make TeX use those variables
+\headline={{\textfonts\rm \ifodd\pageno \the\oddheadline
+                            \else \the\evenheadline \fi}}
+\footline={{\textfonts\rm \ifodd\pageno \the\oddfootline
+                            \else \the\evenfootline \fi}\HEADINGShook}
+\let\HEADINGShook=\relax
+
+% Commands to set those variables.
+% For example, this is what  @headings on  does
+% @evenheading @thistitle|@thispage|@thischapter
+% @oddheading @thischapter|@thispage|@thistitle
+% @evenfooting @thisfile||
+% @oddfooting ||@thisfile
+
+
+\def\evenheading{\parsearg\evenheadingxxx}
+\def\evenheadingxxx #1{\evenheadingyyy #1\|\|\|\|\finish}
+\def\evenheadingyyy #1\|#2\|#3\|#4\finish{%
+\global\evenheadline={\rlap{\centerline{#2}}\line{#1\hfil#3}}}
+
+\def\oddheading{\parsearg\oddheadingxxx}
+\def\oddheadingxxx #1{\oddheadingyyy #1\|\|\|\|\finish}
+\def\oddheadingyyy #1\|#2\|#3\|#4\finish{%
+\global\oddheadline={\rlap{\centerline{#2}}\line{#1\hfil#3}}}
+
+\parseargdef\everyheading{\oddheadingxxx{#1}\evenheadingxxx{#1}}%
+
+\def\evenfooting{\parsearg\evenfootingxxx}
+\def\evenfootingxxx #1{\evenfootingyyy #1\|\|\|\|\finish}
+\def\evenfootingyyy #1\|#2\|#3\|#4\finish{%
+\global\evenfootline={\rlap{\centerline{#2}}\line{#1\hfil#3}}}
+
+\def\oddfooting{\parsearg\oddfootingxxx}
+\def\oddfootingxxx #1{\oddfootingyyy #1\|\|\|\|\finish}
+\def\oddfootingyyy #1\|#2\|#3\|#4\finish{%
+  \global\oddfootline = {\rlap{\centerline{#2}}\line{#1\hfil#3}}%
+  %
+  % Leave some space for the footline.  Hopefully ok to assume
+  % @evenfooting will not be used by itself.
+  \global\advance\pageheight by -12pt
+  \global\advance\vsize by -12pt
+}
+
+\parseargdef\everyfooting{\oddfootingxxx{#1}\evenfootingxxx{#1}}
+
+
+% @headings double      turns headings on for double-sided printing.
+% @headings single      turns headings on for single-sided printing.
+% @headings off         turns them off.
+% @headings on          same as @headings double, retained for compatibility.
+% @headings after       turns on double-sided headings after this page.
+% @headings doubleafter turns on double-sided headings after this page.
+% @headings singleafter turns on single-sided headings after this page.
+% By default, they are off at the start of a document,
+% and turned `on' after @end titlepage.
+
+\def\headings #1 {\csname HEADINGS#1\endcsname}
+
+\def\HEADINGSoff{%
+\global\evenheadline={\hfil} \global\evenfootline={\hfil}
+\global\oddheadline={\hfil} \global\oddfootline={\hfil}}
+\HEADINGSoff
+% When we turn headings on, set the page number to 1.
+% For double-sided printing, put current file name in lower left corner,
+% chapter name on inside top of right hand pages, document
+% title on inside top of left hand pages, and page numbers on outside top
+% edge of all pages.
+\def\HEADINGSdouble{%
+\global\pageno=1
+\global\evenfootline={\hfil}
+\global\oddfootline={\hfil}
+\global\evenheadline={\line{\folio\hfil\thistitle}}
+\global\oddheadline={\line{\thischapter\hfil\folio}}
+\global\let\contentsalignmacro = \chapoddpage
+}
+\let\contentsalignmacro = \chappager
+
+% For single-sided printing, chapter title goes across top left of page,
+% page number on top right.
+\def\HEADINGSsingle{%
+\global\pageno=1
+\global\evenfootline={\hfil}
+\global\oddfootline={\hfil}
+\global\evenheadline={\line{\thischapter\hfil\folio}}
+\global\oddheadline={\line{\thischapter\hfil\folio}}
+\global\let\contentsalignmacro = \chappager
+}
+\def\HEADINGSon{\HEADINGSdouble}
+
+\def\HEADINGSafter{\let\HEADINGShook=\HEADINGSdoublex}
+\let\HEADINGSdoubleafter=\HEADINGSafter
+\def\HEADINGSdoublex{%
+\global\evenfootline={\hfil}
+\global\oddfootline={\hfil}
+\global\evenheadline={\line{\folio\hfil\thistitle}}
+\global\oddheadline={\line{\thischapter\hfil\folio}}
+\global\let\contentsalignmacro = \chapoddpage
+}
+
+\def\HEADINGSsingleafter{\let\HEADINGShook=\HEADINGSsinglex}
+\def\HEADINGSsinglex{%
+\global\evenfootline={\hfil}
+\global\oddfootline={\hfil}
+\global\evenheadline={\line{\thischapter\hfil\folio}}
+\global\oddheadline={\line{\thischapter\hfil\folio}}
+\global\let\contentsalignmacro = \chappager
+}
+
+% Subroutines used in generating headings
+% This produces Day Month Year style of output.
+% Only define if not already defined, in case a txi-??.tex file has set
+% up a different format (e.g., txi-cs.tex does this).
+\ifx\today\undefined
+\def\today{%
+  \number\day\space
+  \ifcase\month
+  \or\putwordMJan\or\putwordMFeb\or\putwordMMar\or\putwordMApr
+  \or\putwordMMay\or\putwordMJun\or\putwordMJul\or\putwordMAug
+  \or\putwordMSep\or\putwordMOct\or\putwordMNov\or\putwordMDec
+  \fi
+  \space\number\year}
+\fi
+
+% @settitle line...  specifies the title of the document, for headings.
+% It generates no output of its own.
+\def\thistitle{\putwordNoTitle}
+\def\settitle{\parsearg{\gdef\thistitle}}
+
+
+\message{tables,}
+% Tables -- @table, @ftable, @vtable, @item(x).
+
+% default indentation of table text
+\newdimen\tableindent \tableindent=.8in
+% default indentation of @itemize and @enumerate text
+\newdimen\itemindent  \itemindent=.3in
+% margin between end of table item and start of table text.
+\newdimen\itemmargin  \itemmargin=.1in
+
+% used internally for \itemindent minus \itemmargin
+\newdimen\itemmax
+
+% Note @table, @ftable, and @vtable define @item, @itemx, etc., with
+% these defs.
+% They also define \itemindex
+% to index the item name in whatever manner is desired (perhaps none).
+
+\newif\ifitemxneedsnegativevskip
+
+\def\itemxpar{\par\ifitemxneedsnegativevskip\nobreak\vskip-\parskip\nobreak\fi}
+
+\def\internalBitem{\smallbreak \parsearg\itemzzz}
+\def\internalBitemx{\itemxpar \parsearg\itemzzz}
+
+\def\itemzzz #1{\begingroup %
+  \advance\hsize by -\rightskip
+  \advance\hsize by -\tableindent
+  \setbox0=\hbox{\itemindicate{#1}}%
+  \itemindex{#1}%
+  \nobreak % This prevents a break before @itemx.
+  %
+  % If the item text does not fit in the space we have, put it on a line
+  % by itself, and do not allow a page break either before or after that
+  % line.  We do not start a paragraph here because then if the next
+  % command is, e.g., @kindex, the whatsit would get put into the
+  % horizontal list on a line by itself, resulting in extra blank space.
+  \ifdim \wd0>\itemmax
+    %
+    % Make this a paragraph so we get the \parskip glue and wrapping,
+    % but leave it ragged-right.
+    \begingroup
+      \advance\leftskip by-\tableindent
+      \advance\hsize by\tableindent
+      \advance\rightskip by0pt plus1fil
+      \leavevmode\unhbox0\par
+    \endgroup
+    %
+    % We're going to be starting a paragraph, but we don't want the
+    % \parskip glue -- logically it's part of the @item we just started.
+    \nobreak \vskip-\parskip
+    %
+    % Stop a page break at the \parskip glue coming up.  However, if
+    % what follows is an environment such as @example, there will be no
+    % \parskip glue; then the negative vskip we just inserted would
+    % cause the example and the item to crash together.  So we use this
+    % bizarre value of 10001 as a signal to \aboveenvbreak to insert
+    % \parskip glue after all.  Section titles are handled this way also.
+    % 
+    \penalty 10001
+    \endgroup
+    \itemxneedsnegativevskipfalse
+  \else
+    % The item text fits into the space.  Start a paragraph, so that the
+    % following text (if any) will end up on the same line.
+    \noindent
+    % Do this with kerns and \unhbox so that if there is a footnote in
+    % the item text, it can migrate to the main vertical list and
+    % eventually be printed.
+    \nobreak\kern-\tableindent
+    \dimen0 = \itemmax  \advance\dimen0 by \itemmargin \advance\dimen0 by -\wd0
+    \unhbox0
+    \nobreak\kern\dimen0
+    \endgroup
+    \itemxneedsnegativevskiptrue
+  \fi
+}
+
+\def\item{\errmessage{@item while not in a list environment}}
+\def\itemx{\errmessage{@itemx while not in a list environment}}
+
+% @table, @ftable, @vtable.
+\envdef\table{%
+  \let\itemindex\gobble
+  \tablecheck{table}%
+}
+\envdef\ftable{%
+  \def\itemindex ##1{\doind {fn}{\code{##1}}}%
+  \tablecheck{ftable}%
+}
+\envdef\vtable{%
+  \def\itemindex ##1{\doind {vr}{\code{##1}}}%
+  \tablecheck{vtable}%
+}
+\def\tablecheck#1{%
+  \ifnum \the\catcode`\^^M=\active
+    \endgroup
+    \errmessage{This command won't work in this context; perhaps the problem is
+      that we are \inenvironment\thisenv}%
+    \def\next{\doignore{#1}}%
+  \else
+    \let\next\tablex
+  \fi
+  \next
+}
+\def\tablex#1{%
+  \def\itemindicate{#1}%
+  \parsearg\tabley
+}
+\def\tabley#1{%
+  {%
+    \makevalueexpandable
+    \edef\temp{\noexpand\tablez #1\space\space\space}%
+    \expandafter
+  }\temp \endtablez
+}
+\def\tablez #1 #2 #3 #4\endtablez{%
+  \aboveenvbreak
+  \ifnum 0#1>0 \advance \leftskip by #1\mil \fi
+  \ifnum 0#2>0 \tableindent=#2\mil \fi
+  \ifnum 0#3>0 \advance \rightskip by #3\mil \fi
+  \itemmax=\tableindent
+  \advance \itemmax by -\itemmargin
+  \advance \leftskip by \tableindent
+  \exdentamount=\tableindent
+  \parindent = 0pt
+  \parskip = \smallskipamount
+  \ifdim \parskip=0pt \parskip=2pt \fi
+  \let\item = \internalBitem
+  \let\itemx = \internalBitemx
+}
+\def\Etable{\endgraf\afterenvbreak}
+\let\Eftable\Etable
+\let\Evtable\Etable
+\let\Eitemize\Etable
+\let\Eenumerate\Etable
+
+% This is the counter used by @enumerate, which is really @itemize
+
+\newcount \itemno
+
+\envdef\itemize{\parsearg\doitemize}
+
+\def\doitemize#1{%
+  \aboveenvbreak
+  \itemmax=\itemindent
+  \advance\itemmax by -\itemmargin
+  \advance\leftskip by \itemindent
+  \exdentamount=\itemindent
+  \parindent=0pt
+  \parskip=\smallskipamount
+  \ifdim\parskip=0pt \parskip=2pt \fi
+  \def\itemcontents{#1}%
+  % @itemize with no arg is equivalent to @itemize @bullet.
+  \ifx\itemcontents\empty\def\itemcontents{\bullet}\fi
+  \let\item=\itemizeitem
+}
+
+% Definition of @item while inside @itemize and @enumerate.
+%
+\def\itemizeitem{%
+  \advance\itemno by 1  % for enumerations
+  {\let\par=\endgraf \smallbreak}% reasonable place to break
+  {%
+   % If the document has an @itemize directly after a section title, a
+   % \nobreak will be last on the list, and \sectionheading will have
+   % done a \vskip-\parskip.  In that case, we don't want to zero
+   % parskip, or the item text will crash with the heading.  On the
+   % other hand, when there is normal text preceding the item (as there
+   % usually is), we do want to zero parskip, or there would be too much
+   % space.  In that case, we won't have a \nobreak before.  At least
+   % that's the theory.
+   \ifnum\lastpenalty<10000 \parskip=0in \fi
+   \noindent
+   \hbox to 0pt{\hss \itemcontents \kern\itemmargin}%
+   \vadjust{\penalty 1200}}% not good to break after first line of item.
+  \flushcr
+}
+
+% \splitoff TOKENS\endmark defines \first to be the first token in
+% TOKENS, and \rest to be the remainder.
+%
+\def\splitoff#1#2\endmark{\def\first{#1}\def\rest{#2}}%
+
+% Allow an optional argument of an uppercase letter, lowercase letter,
+% or number, to specify the first label in the enumerated list.  No
+% argument is the same as `1'.
+%
+\envparseargdef\enumerate{\enumeratey #1  \endenumeratey}
+\def\enumeratey #1 #2\endenumeratey{%
+  % If we were given no argument, pretend we were given `1'.
+  \def\thearg{#1}%
+  \ifx\thearg\empty \def\thearg{1}\fi
+  %
+  % Detect if the argument is a single token.  If so, it might be a
+  % letter.  Otherwise, the only valid thing it can be is a number.
+  % (We will always have one token, because of the test we just made.
+  % This is a good thing, since \splitoff doesn't work given nothing at
+  % all -- the first parameter is undelimited.)
+  \expandafter\splitoff\thearg\endmark
+  \ifx\rest\empty
+    % Only one token in the argument.  It could still be anything.
+    % A ``lowercase letter'' is one whose \lccode is nonzero.
+    % An ``uppercase letter'' is one whose \lccode is both nonzero, and
+    %   not equal to itself.
+    % Otherwise, we assume it's a number.
+    %
+    % We need the \relax at the end of the \ifnum lines to stop TeX from
+    % continuing to look for a <number>.
+    %
+    \ifnum\lccode\expandafter`\thearg=0\relax
+      \numericenumerate % a number (we hope)
+    \else
+      % It's a letter.
+      \ifnum\lccode\expandafter`\thearg=\expandafter`\thearg\relax
+        \lowercaseenumerate % lowercase letter
+      \else
+        \uppercaseenumerate % uppercase letter
+      \fi
+    \fi
+  \else
+    % Multiple tokens in the argument.  We hope it's a number.
+    \numericenumerate
+  \fi
+}
+
+% An @enumerate whose labels are integers.  The starting integer is
+% given in \thearg.
+%
+\def\numericenumerate{%
+  \itemno = \thearg
+  \startenumeration{\the\itemno}%
+}
+
+% The starting (lowercase) letter is in \thearg.
+\def\lowercaseenumerate{%
+  \itemno = \expandafter`\thearg
+  \startenumeration{%
+    % Be sure we're not beyond the end of the alphabet.
+    \ifnum\itemno=0
+      \errmessage{No more lowercase letters in @enumerate; get a bigger
+                  alphabet}%
+    \fi
+    \char\lccode\itemno
+  }%
+}
+
+% The starting (uppercase) letter is in \thearg.
+\def\uppercaseenumerate{%
+  \itemno = \expandafter`\thearg
+  \startenumeration{%
+    % Be sure we're not beyond the end of the alphabet.
+    \ifnum\itemno=0
+      \errmessage{No more uppercase letters in @enumerate; get a bigger
+                  alphabet}
+    \fi
+    \char\uccode\itemno
+  }%
+}
+
+% Call \doitemize, adding a period to the first argument and supplying the
+% common last two arguments.  Also subtract one from the initial value in
+% \itemno, since @item increments \itemno.
+%
+\def\startenumeration#1{%
+  \advance\itemno by -1
+  \doitemize{#1.}\flushcr
+}
+
+% @alphaenumerate and @capsenumerate are abbreviations for giving an arg
+% to @enumerate.
+%
+\def\alphaenumerate{\enumerate{a}}
+\def\capsenumerate{\enumerate{A}}
+\def\Ealphaenumerate{\Eenumerate}
+\def\Ecapsenumerate{\Eenumerate}
+
+
+% @multitable macros
+% Amy Hendrickson, 8/18/94, 3/6/96
+%
+% @multitable ... @end multitable will make as many columns as desired.
+% Contents of each column will wrap at width given in preamble.  Width
+% can be specified either with sample text given in a template line,
+% or in percent of \hsize, the current width of text on page.
+
+% Table can continue over pages but will only break between lines.
+
+% To make preamble:
+%
+% Either define widths of columns in terms of percent of \hsize:
+%   @multitable @columnfractions .25 .3 .45
+%   @item ...
+%
+%   Numbers following @columnfractions are the percent of the total
+%   current hsize to be used for each column. You may use as many
+%   columns as desired.
+
+
+% Or use a template:
+%   @multitable {Column 1 template} {Column 2 template} {Column 3 template}
+%   @item ...
+%   using the widest term desired in each column.
+
+% Each new table line starts with @item, each subsequent new column
+% starts with @tab. Empty columns may be produced by supplying @tab's
+% with nothing between them for as many times as empty columns are needed,
+% ie, @tab@tab@tab will produce two empty columns.
+
+% @item, @tab do not need to be on their own lines, but it will not hurt
+% if they are.
+
+% Sample multitable:
+
+%   @multitable {Column 1 template} {Column 2 template} {Column 3 template}
+%   @item first col stuff @tab second col stuff @tab third col
+%   @item
+%   first col stuff
+%   @tab
+%   second col stuff
+%   @tab
+%   third col
+%   @item first col stuff @tab second col stuff
+%   @tab Many paragraphs of text may be used in any column.
+%
+%         They will wrap at the width determined by the template.
+%   @item@tab@tab This will be in third column.
+%   @end multitable
+
+% Default dimensions may be reset by user.
+% @multitableparskip is vertical space between paragraphs in table.
+% @multitableparindent is paragraph indent in table.
+% @multitablecolmargin is horizontal space to be left between columns.
+% @multitablelinespace is space to leave between table items, baseline
+%                                                            to baseline.
+%   0pt means it depends on current normal line spacing.
+%
+\newskip\multitableparskip
+\newskip\multitableparindent
+\newdimen\multitablecolspace
+\newskip\multitablelinespace
+\multitableparskip=0pt
+\multitableparindent=6pt
+\multitablecolspace=12pt
+\multitablelinespace=0pt
+
+% Macros used to set up halign preamble:
+%
+\let\endsetuptable\relax
+\def\xendsetuptable{\endsetuptable}
+\let\columnfractions\relax
+\def\xcolumnfractions{\columnfractions}
+\newif\ifsetpercent
+
+% #1 is the @columnfraction, usually a decimal number like .5, but might
+% be just 1.  We just use it, whatever it is.
+%
+\def\pickupwholefraction#1 {%
+  \global\advance\colcount by 1
+  \expandafter\xdef\csname col\the\colcount\endcsname{#1\hsize}%
+  \setuptable
+}
+
+\newcount\colcount
+\def\setuptable#1{%
+  \def\firstarg{#1}%
+  \ifx\firstarg\xendsetuptable
+    \let\go = \relax
+  \else
+    \ifx\firstarg\xcolumnfractions
+      \global\setpercenttrue
+    \else
+      \ifsetpercent
+         \let\go\pickupwholefraction
+      \else
+         \global\advance\colcount by 1
+         \setbox0=\hbox{#1\unskip\space}% Add a normal word space as a
+                   % separator; typically that is always in the input, anyway.
+         \expandafter\xdef\csname col\the\colcount\endcsname{\the\wd0}%
+      \fi
+    \fi
+    \ifx\go\pickupwholefraction
+      % Put the argument back for the \pickupwholefraction call, so
+      % we'll always have a period there to be parsed.
+      \def\go{\pickupwholefraction#1}%
+    \else
+      \let\go = \setuptable
+    \fi%
+  \fi
+  \go
+}
+
+% multitable-only commands.
+%
+% @headitem starts a heading row, which we typeset in bold.
+% Assignments have to be global since we are inside the implicit group
+% of an alignment entry.  Note that \everycr resets \everytab.
+\def\headitem{\checkenv\multitable \crcr \global\everytab={\bf}\the\everytab}%
+%
+% A \tab used to include \hskip1sp.  But then the space in a template
+% line is not enough.  That is bad.  So let's go back to just `&' until
+% we encounter the problem it was intended to solve again.
+%					--karl, nathan@acm.org, 20apr99.
+\def\tab{\checkenv\multitable &\the\everytab}%
+
+% @multitable ... @end multitable definitions:
+%
+\newtoks\everytab  % insert after every tab.
+%
+\envdef\multitable{%
+  \vskip\parskip
+  \startsavinginserts
+  %
+  % @item within a multitable starts a normal row.
+  % We use \def instead of \let so that if one of the multitable entries
+  % contains an @itemize, we don't choke on the \item (seen as \crcr aka
+  % \endtemplate) expanding \doitemize.
+  \def\item{\crcr}%
+  %
+  \tolerance=9500
+  \hbadness=9500
+  \setmultitablespacing
+  \parskip=\multitableparskip
+  \parindent=\multitableparindent
+  \overfullrule=0pt
+  \global\colcount=0
+  %
+  \everycr = {%
+    \noalign{%
+      \global\everytab={}%
+      \global\colcount=0 % Reset the column counter.
+      % Check for saved footnotes, etc.
+      \checkinserts
+      % Keeps underfull box messages off when table breaks over pages.
+      %\filbreak
+	% Maybe so, but it also creates really weird page breaks when the
+	% table breaks over pages. Wouldn't \vfil be better?  Wait until the
+	% problem manifests itself, so it can be fixed for real --karl.
+    }%
+  }%
+  %
+  \parsearg\domultitable
+}
+\def\domultitable#1{%
+  % To parse everything between @multitable and @item:
+  \setuptable#1 \endsetuptable
+  %
+  % This preamble sets up a generic column definition, which will
+  % be used as many times as user calls for columns.
+  % \vtop will set a single line and will also let text wrap and
+  % continue for many paragraphs if desired.
+  \halign\bgroup &%
+    \global\advance\colcount by 1
+    \multistrut
+    \vtop{%
+      % Use the current \colcount to find the correct column width:
+      \hsize=\expandafter\csname col\the\colcount\endcsname
+      %
+      % In order to keep entries from bumping into each other
+      % we will add a \leftskip of \multitablecolspace to all columns after
+      % the first one.
+      %
+      % If a template has been used, we will add \multitablecolspace
+      % to the width of each template entry.
+      %
+      % If the user has set preamble in terms of percent of \hsize we will
+      % use that dimension as the width of the column, and the \leftskip
+      % will keep entries from bumping into each other.  Table will start at
+      % left margin and final column will justify at right margin.
+      %
+      % Make sure we don't inherit \rightskip from the outer environment.
+      \rightskip=0pt
+      \ifnum\colcount=1
+	% The first column will be indented with the surrounding text.
+	\advance\hsize by\leftskip
+      \else
+	\ifsetpercent \else
+	  % If user has not set preamble in terms of percent of \hsize
+	  % we will advance \hsize by \multitablecolspace.
+	  \advance\hsize by \multitablecolspace
+	\fi
+       % In either case we will make \leftskip=\multitablecolspace:
+      \leftskip=\multitablecolspace
+      \fi
+      % Ignoring space at the beginning and end avoids an occasional spurious
+      % blank line, when TeX decides to break the line at the space before the
+      % box from the multistrut, so the strut ends up on a line by itself.
+      % For example:
+      % @multitable @columnfractions .11 .89
+      % @item @code{#}
+      % @tab Legal holiday which is valid in major parts of the whole country.
+      % Is automatically provided with highlighting sequences respectively
+      % marking characters.
+      \noindent\ignorespaces##\unskip\multistrut
+    }\cr
+}
+\def\Emultitable{%
+  \crcr
+  \egroup % end the \halign
+  \global\setpercentfalse
+}
+
+\def\setmultitablespacing{%
+  \def\multistrut{\strut}% just use the standard line spacing
+  %
+  % Compute \multitablelinespace (if not defined by user) for use in
+  % \multitableparskip calculation.  We used define \multistrut based on
+  % this, but (ironically) that caused the spacing to be off.
+  % See bug-texinfo report from Werner Lemberg, 31 Oct 2004 12:52:20 +0100.
+\ifdim\multitablelinespace=0pt
+\setbox0=\vbox{X}\global\multitablelinespace=\the\baselineskip
+\global\advance\multitablelinespace by-\ht0
+\fi
+%% Test to see if parskip is larger than space between lines of
+%% table. If not, do nothing.
+%%        If so, set to same dimension as multitablelinespace.
+\ifdim\multitableparskip>\multitablelinespace
+\global\multitableparskip=\multitablelinespace
+\global\advance\multitableparskip-7pt %% to keep parskip somewhat smaller
+                                      %% than skip between lines in the table.
+\fi%
+\ifdim\multitableparskip=0pt
+\global\multitableparskip=\multitablelinespace
+\global\advance\multitableparskip-7pt %% to keep parskip somewhat smaller
+                                      %% than skip between lines in the table.
+\fi}
+
+
+\message{conditionals,}
+
+% @iftex, @ifnotdocbook, @ifnothtml, @ifnotinfo, @ifnotplaintext,
+% @ifnotxml always succeed.  They currently do nothing; we don't
+% attempt to check whether the conditionals are properly nested.  But we
+% have to remember that they are conditionals, so that @end doesn't
+% attempt to close an environment group.
+%
+\def\makecond#1{%
+  \expandafter\let\csname #1\endcsname = \relax
+  \expandafter\let\csname iscond.#1\endcsname = 1
+}
+\makecond{iftex}
+\makecond{ifnotdocbook}
+\makecond{ifnothtml}
+\makecond{ifnotinfo}
+\makecond{ifnotplaintext}
+\makecond{ifnotxml}
+
+% Ignore @ignore, @ifhtml, @ifinfo, and the like.
+%
+\def\direntry{\doignore{direntry}}
+\def\documentdescription{\doignore{documentdescription}}
+\def\docbook{\doignore{docbook}}
+\def\html{\doignore{html}}
+\def\ifdocbook{\doignore{ifdocbook}}
+\def\ifhtml{\doignore{ifhtml}}
+\def\ifinfo{\doignore{ifinfo}}
+\def\ifnottex{\doignore{ifnottex}}
+\def\ifplaintext{\doignore{ifplaintext}}
+\def\ifxml{\doignore{ifxml}}
+\def\ignore{\doignore{ignore}}
+\def\menu{\doignore{menu}}
+\def\xml{\doignore{xml}}
+
+% Ignore text until a line `@end #1', keeping track of nested conditionals.
+%
+% A count to remember the depth of nesting.
+\newcount\doignorecount
+
+\def\doignore#1{\begingroup
+  % Scan in ``verbatim'' mode:
+  \obeylines
+  \catcode`\@ = \other
+  \catcode`\{ = \other
+  \catcode`\} = \other
+  %
+  % Make sure that spaces turn into tokens that match what \doignoretext wants.
+  \spaceisspace
+  %
+  % Count number of #1's that we've seen.
+  \doignorecount = 0
+  %
+  % Swallow text until we reach the matching `@end #1'.
+  \dodoignore{#1}%
+}
+
+{ \catcode`_=11 % We want to use \_STOP_ which cannot appear in texinfo source.
+  \obeylines %
+  %
+  \gdef\dodoignore#1{%
+    % #1 contains the command name as a string, e.g., `ifinfo'.
+    %
+    % Define a command to find the next `@end #1'.
+    \long\def\doignoretext##1^^M@end #1{%
+      \doignoretextyyy##1^^M@#1\_STOP_}%
+    %
+    % And this command to find another #1 command, at the beginning of a
+    % line.  (Otherwise, we would consider a line `@c @ifset', for
+    % example, to count as an @ifset for nesting.)
+    \long\def\doignoretextyyy##1^^M@#1##2\_STOP_{\doignoreyyy{##2}\_STOP_}%
+    %
+    % And now expand that command.
+    \doignoretext ^^M%
+  }%
+}
+
+\def\doignoreyyy#1{%
+  \def\temp{#1}%
+  \ifx\temp\empty			% Nothing found.
+    \let\next\doignoretextzzz
+  \else					% Found a nested condition, ...
+    \advance\doignorecount by 1
+    \let\next\doignoretextyyy		% ..., look for another.
+    % If we're here, #1 ends with ^^M\ifinfo (for example).
+  \fi
+  \next #1% the token \_STOP_ is present just after this macro.
+}
+
+% We have to swallow the remaining "\_STOP_".
+%
+\def\doignoretextzzz#1{%
+  \ifnum\doignorecount = 0	% We have just found the outermost @end.
+    \let\next\enddoignore
+  \else				% Still inside a nested condition.
+    \advance\doignorecount by -1
+    \let\next\doignoretext      % Look for the next @end.
+  \fi
+  \next
+}
+
+% Finish off ignored text.
+{ \obeylines%
+  % Ignore anything after the last `@end #1'; this matters in verbatim
+  % environments, where otherwise the newline after an ignored conditional
+  % would result in a blank line in the output.
+  \gdef\enddoignore#1^^M{\endgroup\ignorespaces}%
+}
+
+
+% @set VAR sets the variable VAR to an empty value.
+% @set VAR REST-OF-LINE sets VAR to the value REST-OF-LINE.
+%
+% Since we want to separate VAR from REST-OF-LINE (which might be
+% empty), we can't just use \parsearg; we have to insert a space of our
+% own to delimit the rest of the line, and then take it out again if we
+% didn't need it.
+% We rely on the fact that \parsearg sets \catcode`\ =10.
+%
+\parseargdef\set{\setyyy#1 \endsetyyy}
+\def\setyyy#1 #2\endsetyyy{%
+  {%
+    \makevalueexpandable
+    \def\temp{#2}%
+    \edef\next{\gdef\makecsname{SET#1}}%
+    \ifx\temp\empty
+      \next{}%
+    \else
+      \setzzz#2\endsetzzz
+    \fi
+  }%
+}
+% Remove the trailing space \setxxx inserted.
+\def\setzzz#1 \endsetzzz{\next{#1}}
+
+% @clear VAR clears (i.e., unsets) the variable VAR.
+%
+\parseargdef\clear{%
+  {%
+    \makevalueexpandable
+    \global\expandafter\let\csname SET#1\endcsname=\relax
+  }%
+}
+
+% @value{foo} gets the text saved in variable foo.
+\def\value{\begingroup\makevalueexpandable\valuexxx}
+\def\valuexxx#1{\expandablevalue{#1}\endgroup}
+{
+  \catcode`\- = \active \catcode`\_ = \active
+  %
+  \gdef\makevalueexpandable{%
+    \let\value = \expandablevalue
+    % We don't want these characters active, ...
+    \catcode`\-=\other \catcode`\_=\other
+    % ..., but we might end up with active ones in the argument if
+    % we're called from @code, as @code{@value{foo-bar_}}, though.
+    % So \let them to their normal equivalents.
+    \let-\realdash \let_\normalunderscore
+  }
+}
+
+% We have this subroutine so that we can handle at least some @value's
+% properly in indexes (we call \makevalueexpandable in \indexdummies).
+% The command has to be fully expandable (if the variable is set), since
+% the result winds up in the index file.  This means that if the
+% variable's value contains other Texinfo commands, it's almost certain
+% it will fail (although perhaps we could fix that with sufficient work
+% to do a one-level expansion on the result, instead of complete).
+%
+\def\expandablevalue#1{%
+  \expandafter\ifx\csname SET#1\endcsname\relax
+    {[No value for ``#1'']}%
+    \message{Variable `#1', used in @value, is not set.}%
+  \else
+    \csname SET#1\endcsname
+  \fi
+}
+
+% @ifset VAR ... @end ifset reads the `...' iff VAR has been defined
+% with @set.
+%
+% To get special treatment of `@end ifset,' call \makeond and the redefine.
+%
+\makecond{ifset}
+\def\ifset{\parsearg{\doifset{\let\next=\ifsetfail}}}
+\def\doifset#1#2{%
+  {%
+    \makevalueexpandable
+    \let\next=\empty
+    \expandafter\ifx\csname SET#2\endcsname\relax
+      #1% If not set, redefine \next.
+    \fi
+    \expandafter
+  }\next
+}
+\def\ifsetfail{\doignore{ifset}}
+
+% @ifclear VAR ... @end ifclear reads the `...' iff VAR has never been
+% defined with @set, or has been undefined with @clear.
+%
+% The `\else' inside the `\doifset' parameter is a trick to reuse the
+% above code: if the variable is not set, do nothing, if it is set,
+% then redefine \next to \ifclearfail.
+%
+\makecond{ifclear}
+\def\ifclear{\parsearg{\doifset{\else \let\next=\ifclearfail}}}
+\def\ifclearfail{\doignore{ifclear}}
+
+% @dircategory CATEGORY  -- specify a category of the dir file
+% which this file should belong to.  Ignore this in TeX.
+\let\dircategory=\comment
+
+% @defininfoenclose.
+\let\definfoenclose=\comment
+
+
+\message{indexing,}
+% Index generation facilities
+
+% Define \newwrite to be identical to plain tex's \newwrite
+% except not \outer, so it can be used within macros and \if's.
+\edef\newwrite{\makecsname{ptexnewwrite}}
+
+% \newindex {foo} defines an index named foo.
+% It automatically defines \fooindex such that
+% \fooindex ...rest of line... puts an entry in the index foo.
+% It also defines \fooindfile to be the number of the output channel for
+% the file that accumulates this index.  The file's extension is foo.
+% The name of an index should be no more than 2 characters long
+% for the sake of vms.
+%
+\def\newindex#1{%
+  \iflinks
+    \expandafter\newwrite \csname#1indfile\endcsname
+    \openout \csname#1indfile\endcsname \jobname.#1 % Open the file
+  \fi
+  \expandafter\xdef\csname#1index\endcsname{%     % Define @#1index
+    \noexpand\doindex{#1}}
+}
+
+% @defindex foo  ==  \newindex{foo}
+%
+\def\defindex{\parsearg\newindex}
+
+% Define @defcodeindex, like @defindex except put all entries in @code.
+%
+\def\defcodeindex{\parsearg\newcodeindex}
+%
+\def\newcodeindex#1{%
+  \iflinks
+    \expandafter\newwrite \csname#1indfile\endcsname
+    \openout \csname#1indfile\endcsname \jobname.#1
+  \fi
+  \expandafter\xdef\csname#1index\endcsname{%
+    \noexpand\docodeindex{#1}}%
+}
+
+
+% @synindex foo bar    makes index foo feed into index bar.
+% Do this instead of @defindex foo if you don't want it as a separate index.
+%
+% @syncodeindex foo bar   similar, but put all entries made for index foo
+% inside @code.
+%
+\def\synindex#1 #2 {\dosynindex\doindex{#1}{#2}}
+\def\syncodeindex#1 #2 {\dosynindex\docodeindex{#1}{#2}}
+
+% #1 is \doindex or \docodeindex, #2 the index getting redefined (foo),
+% #3 the target index (bar).
+\def\dosynindex#1#2#3{%
+  % Only do \closeout if we haven't already done it, else we'll end up
+  % closing the target index.
+  \expandafter \ifx\csname donesynindex#2\endcsname \undefined
+    % The \closeout helps reduce unnecessary open files; the limit on the
+    % Acorn RISC OS is a mere 16 files.
+    \expandafter\closeout\csname#2indfile\endcsname
+    \expandafter\let\csname\donesynindex#2\endcsname = 1
+  \fi
+  % redefine \fooindfile:
+  \expandafter\let\expandafter\temp\expandafter=\csname#3indfile\endcsname
+  \expandafter\let\csname#2indfile\endcsname=\temp
+  % redefine \fooindex:
+  \expandafter\xdef\csname#2index\endcsname{\noexpand#1{#3}}%
+}
+
+% Define \doindex, the driver for all \fooindex macros.
+% Argument #1 is generated by the calling \fooindex macro,
+%  and it is "foo", the name of the index.
+
+% \doindex just uses \parsearg; it calls \doind for the actual work.
+% This is because \doind is more useful to call from other macros.
+
+% There is also \dosubind {index}{topic}{subtopic}
+% which makes an entry in a two-level index such as the operation index.
+
+\def\doindex#1{\edef\indexname{#1}\parsearg\singleindexer}
+\def\singleindexer #1{\doind{\indexname}{#1}}
+
+% like the previous two, but they put @code around the argument.
+\def\docodeindex#1{\edef\indexname{#1}\parsearg\singlecodeindexer}
+\def\singlecodeindexer #1{\doind{\indexname}{\code{#1}}}
+
+% Take care of Texinfo commands that can appear in an index entry.
+% Since there are some commands we want to expand, and others we don't,
+% we have to laboriously prevent expansion for those that we don't.
+%
+\def\indexdummies{%
+  \escapechar = `\\     % use backslash in output files.
+  \def\@{@}% change to @@ when we switch to @ as escape char in index files.
+  \def\ {\realbackslash\space }%
+  %
+  % Need these in case \tex is in effect and \{ is a \delimiter again.
+  % But can't use \lbracecmd and \rbracecmd because texindex assumes
+  % braces and backslashes are used only as delimiters.
+  \let\{ = \mylbrace
+  \let\} = \myrbrace
+  %
+  % I don't entirely understand this, but when an index entry is
+  % generated from a macro call, the \endinput which \scanmacro inserts
+  % causes processing to be prematurely terminated.  This is,
+  % apparently, because \indexsorttmp is fully expanded, and \endinput
+  % is an expandable command.  The redefinition below makes \endinput
+  % disappear altogether for that purpose -- although logging shows that
+  % processing continues to some further point.  On the other hand, it
+  % seems \endinput does not hurt in the printed index arg, since that
+  % is still getting written without apparent harm.
+  % 
+  % Sample source (mac-idx3.tex, reported by Graham Percival to
+  % help-texinfo, 22may06):
+  % @macro funindex {WORD}
+  % @findex xyz
+  % @end macro
+  % ...
+  % @funindex commtest
+  % 
+  % The above is not enough to reproduce the bug, but it gives the flavor.
+  % 
+  % Sample whatsit resulting:
+  % .@write3{\entry{xyz}{@folio }{@code {xyz@endinput }}}
+  % 
+  % So:
+  \let\endinput = \empty
+  %
+  % Do the redefinitions.
+  \commondummies
+}
+
+% For the aux and toc files, @ is the escape character.  So we want to
+% redefine everything using @ as the escape character (instead of
+% \realbackslash, still used for index files).  When everything uses @,
+% this will be simpler.
+%
+\def\atdummies{%
+  \def\@{@@}%
+  \def\ {@ }%
+  \let\{ = \lbraceatcmd
+  \let\} = \rbraceatcmd
+  %
+  % Do the redefinitions.
+  \commondummies
+  \otherbackslash
+}
+
+% Called from \indexdummies and \atdummies.
+%
+\def\commondummies{%
+  %
+  % \definedummyword defines \#1 as \string\#1\space, thus effectively
+  % preventing its expansion.  This is used only for control% words,
+  % not control letters, because the \space would be incorrect for
+  % control characters, but is needed to separate the control word
+  % from whatever follows.
+  %
+  % For control letters, we have \definedummyletter, which omits the
+  % space.
+  %
+  % These can be used both for control words that take an argument and
+  % those that do not.  If it is followed by {arg} in the input, then
+  % that will dutifully get written to the index (or wherever).
+  %
+  \def\definedummyword  ##1{\def##1{\string##1\space}}%
+  \def\definedummyletter##1{\def##1{\string##1}}%
+  \let\definedummyaccent\definedummyletter
+  %
+  \commondummiesnofonts
+  %
+  \definedummyletter\_%
+  %
+  % Non-English letters.
+  \definedummyword\AA
+  \definedummyword\AE
+  \definedummyword\L
+  \definedummyword\OE
+  \definedummyword\O
+  \definedummyword\aa
+  \definedummyword\ae
+  \definedummyword\l
+  \definedummyword\oe
+  \definedummyword\o
+  \definedummyword\ss
+  \definedummyword\exclamdown
+  \definedummyword\questiondown
+  \definedummyword\ordf
+  \definedummyword\ordm
+  %
+  % Although these internal commands shouldn't show up, sometimes they do.
+  \definedummyword\bf
+  \definedummyword\gtr
+  \definedummyword\hat
+  \definedummyword\less
+  \definedummyword\sf
+  \definedummyword\sl
+  \definedummyword\tclose
+  \definedummyword\tt
+  %
+  \definedummyword\LaTeX
+  \definedummyword\TeX
+  %
+  % Assorted special characters.
+  \definedummyword\bullet
+  \definedummyword\comma
+  \definedummyword\copyright
+  \definedummyword\registeredsymbol
+  \definedummyword\dots
+  \definedummyword\enddots
+  \definedummyword\equiv
+  \definedummyword\error
+  \definedummyword\euro
+  \definedummyword\expansion
+  \definedummyword\minus
+  \definedummyword\pounds
+  \definedummyword\point
+  \definedummyword\print
+  \definedummyword\result
+  \definedummyword\textdegree
+  %
+  % We want to disable all macros so that they are not expanded by \write.
+  \macrolist
+  %
+  \normalturnoffactive
+  %
+  % Handle some cases of @value -- where it does not contain any
+  % (non-fully-expandable) commands.
+  \makevalueexpandable
+}
+
+% \commondummiesnofonts: common to \commondummies and \indexnofonts.
+%
+\def\commondummiesnofonts{%
+  % Control letters and accents.
+  \definedummyletter\!%
+  \definedummyaccent\"%
+  \definedummyaccent\'%
+  \definedummyletter\*%
+  \definedummyaccent\,%
+  \definedummyletter\.%
+  \definedummyletter\/%
+  \definedummyletter\:%
+  \definedummyaccent\=%
+  \definedummyletter\?%
+  \definedummyaccent\^%
+  \definedummyaccent\`%
+  \definedummyaccent\~%
+  \definedummyword\u
+  \definedummyword\v
+  \definedummyword\H
+  \definedummyword\dotaccent
+  \definedummyword\ringaccent
+  \definedummyword\tieaccent
+  \definedummyword\ubaraccent
+  \definedummyword\udotaccent
+  \definedummyword\dotless
+  %
+  % Texinfo font commands.
+  \definedummyword\b
+  \definedummyword\i
+  \definedummyword\r
+  \definedummyword\sc
+  \definedummyword\t
+  %
+  % Commands that take arguments.
+  \definedummyword\acronym
+  \definedummyword\cite
+  \definedummyword\code
+  \definedummyword\command
+  \definedummyword\dfn
+  \definedummyword\emph
+  \definedummyword\env
+  \definedummyword\file
+  \definedummyword\kbd
+  \definedummyword\key
+  \definedummyword\math
+  \definedummyword\option
+  \definedummyword\pxref
+  \definedummyword\ref
+  \definedummyword\samp
+  \definedummyword\strong
+  \definedummyword\tie
+  \definedummyword\uref
+  \definedummyword\url
+  \definedummyword\var
+  \definedummyword\verb
+  \definedummyword\w
+  \definedummyword\xref
+}
+
+% \indexnofonts is used when outputting the strings to sort the index
+% by, and when constructing control sequence names.  It eliminates all
+% control sequences and just writes whatever the best ASCII sort string
+% would be for a given command (usually its argument).
+%
+\def\indexnofonts{%
+  % Accent commands should become @asis.
+  \def\definedummyaccent##1{\let##1\asis}%
+  % We can just ignore other control letters.
+  \def\definedummyletter##1{\let##1\empty}%
+  % Hopefully, all control words can become @asis.
+  \let\definedummyword\definedummyaccent
+  %
+  \commondummiesnofonts
+  %
+  % Don't no-op \tt, since it isn't a user-level command
+  % and is used in the definitions of the active chars like <, >, |, etc.
+  % Likewise with the other plain tex font commands.
+  %\let\tt=\asis
+  %
+  \def\ { }%
+  \def\@{@}%
+  % how to handle braces?
+  \def\_{\normalunderscore}%
+  %
+  % Non-English letters.
+  \def\AA{AA}%
+  \def\AE{AE}%
+  \def\L{L}%
+  \def\OE{OE}%
+  \def\O{O}%
+  \def\aa{aa}%
+  \def\ae{ae}%
+  \def\l{l}%
+  \def\oe{oe}%
+  \def\o{o}%
+  \def\ss{ss}%
+  \def\exclamdown{!}%
+  \def\questiondown{?}%
+  \def\ordf{a}%
+  \def\ordm{o}%
+  %
+  \def\LaTeX{LaTeX}%
+  \def\TeX{TeX}%
+  %
+  % Assorted special characters.
+  % (The following {} will end up in the sort string, but that's ok.)
+  \def\bullet{bullet}%
+  \def\comma{,}%
+  \def\copyright{copyright}%
+  \def\registeredsymbol{R}%
+  \def\dots{...}%
+  \def\enddots{...}%
+  \def\equiv{==}%
+  \def\error{error}%
+  \def\euro{euro}%
+  \def\expansion{==>}%
+  \def\minus{-}%
+  \def\pounds{pounds}%
+  \def\point{.}%
+  \def\print{-|}%
+  \def\result{=>}%
+  \def\textdegree{degrees}%
+  %
+  % We need to get rid of all macros, leaving only the arguments (if present).
+  % Of course this is not nearly correct, but it is the best we can do for now.
+  % makeinfo does not expand macros in the argument to @deffn, which ends up
+  % writing an index entry, and texindex isn't prepared for an index sort entry
+  % that starts with \.
+  % 
+  % Since macro invocations are followed by braces, we can just redefine them
+  % to take a single TeX argument.  The case of a macro invocation that
+  % goes to end-of-line is not handled.
+  % 
+  \macrolist
+}
+
+\let\indexbackslash=0  %overridden during \printindex.
+\let\SETmarginindex=\relax % put index entries in margin (undocumented)?
+
+% Most index entries go through here, but \dosubind is the general case.
+% #1 is the index name, #2 is the entry text.
+\def\doind#1#2{\dosubind{#1}{#2}{}}
+
+% Workhorse for all \fooindexes.
+% #1 is name of index, #2 is stuff to put there, #3 is subentry --
+% empty if called from \doind, as we usually are (the main exception
+% is with most defuns, which call us directly).
+%
+\def\dosubind#1#2#3{%
+  \iflinks
+  {%
+    % Store the main index entry text (including the third arg).
+    \toks0 = {#2}%
+    % If third arg is present, precede it with a space.
+    \def\thirdarg{#3}%
+    \ifx\thirdarg\empty \else
+      \toks0 = \expandafter{\the\toks0 \space #3}%
+    \fi
+    %
+    \edef\writeto{\csname#1indfile\endcsname}%
+    %
+    \ifvmode
+      \dosubindsanitize
+    \else
+      \dosubindwrite
+    \fi
+  }%
+  \fi
+}
+
+% Write the entry in \toks0 to the index file:
+%
+\def\dosubindwrite{%
+  % Put the index entry in the margin if desired.
+  \ifx\SETmarginindex\relax\else
+    \insert\margin{\hbox{\vrule height8pt depth3pt width0pt \the\toks0}}%
+  \fi
+  %
+  % Remember, we are within a group.
+  \indexdummies % Must do this here, since \bf, etc expand at this stage
+  \def\backslashcurfont{\indexbackslash}% \indexbackslash isn't defined now
+      % so it will be output as is; and it will print as backslash.
+  %
+  % Process the index entry with all font commands turned off, to
+  % get the string to sort by.
+  {\indexnofonts
+   \edef\temp{\the\toks0}% need full expansion
+   \xdef\indexsorttmp{\temp}%
+  }%
+  %
+  % Set up the complete index entry, with both the sort key and
+  % the original text, including any font commands.  We write
+  % three arguments to \entry to the .?? file (four in the
+  % subentry case), texindex reduces to two when writing the .??s
+  % sorted result.
+  \edef\temp{%
+    \write\writeto{%
+      \string\entry{\indexsorttmp}{\noexpand\folio}{\the\toks0}}%
+  }%
+  \temp
+}
+
+% Take care of unwanted page breaks:
+%
+% If a skip is the last thing on the list now, preserve it
+% by backing up by \lastskip, doing the \write, then inserting
+% the skip again.  Otherwise, the whatsit generated by the
+% \write will make \lastskip zero.  The result is that sequences
+% like this:
+% @end defun
+% @tindex whatever
+% @defun ...
+% will have extra space inserted, because the \medbreak in the
+% start of the @defun won't see the skip inserted by the @end of
+% the previous defun.
+%
+% But don't do any of this if we're not in vertical mode.  We
+% don't want to do a \vskip and prematurely end a paragraph.
+%
+% Avoid page breaks due to these extra skips, too.
+%
+% But wait, there is a catch there:
+% We'll have to check whether \lastskip is zero skip.  \ifdim is not
+% sufficient for this purpose, as it ignores stretch and shrink parts
+% of the skip.  The only way seems to be to check the textual
+% representation of the skip.
+%
+% The following is almost like \def\zeroskipmacro{0.0pt} except that
+% the ``p'' and ``t'' characters have catcode \other, not 11 (letter).
+%
+\edef\zeroskipmacro{\expandafter\the\csname z@skip\endcsname}
+%
+% ..., ready, GO:
+%
+\def\dosubindsanitize{%
+  % \lastskip and \lastpenalty cannot both be nonzero simultaneously.
+  \skip0 = \lastskip
+  \edef\lastskipmacro{\the\lastskip}%
+  \count255 = \lastpenalty
+  %
+  % If \lastskip is nonzero, that means the last item was a
+  % skip.  And since a skip is discardable, that means this
+  % -\skip0 glue we're inserting is preceded by a
+  % non-discardable item, therefore it is not a potential
+  % breakpoint, therefore no \nobreak needed.
+  \ifx\lastskipmacro\zeroskipmacro
+  \else
+    \vskip-\skip0
+  \fi
+  %
+  \dosubindwrite
+  %
+  \ifx\lastskipmacro\zeroskipmacro
+    % If \lastskip was zero, perhaps the last item was a penalty, and
+    % perhaps it was >=10000, e.g., a \nobreak.  In that case, we want
+    % to re-insert the same penalty (values >10000 are used for various
+    % signals); since we just inserted a non-discardable item, any
+    % following glue (such as a \parskip) would be a breakpoint.  For example:
+    % 
+    %   @deffn deffn-whatever
+    %   @vindex index-whatever
+    %   Description.
+    % would allow a break between the index-whatever whatsit
+    % and the "Description." paragraph.
+    \ifnum\count255>9999 \penalty\count255 \fi
+  \else
+    % On the other hand, if we had a nonzero \lastskip,
+    % this make-up glue would be preceded by a non-discardable item
+    % (the whatsit from the \write), so we must insert a \nobreak.
+    \nobreak\vskip\skip0
+  \fi
+}
+
+% The index entry written in the file actually looks like
+%  \entry {sortstring}{page}{topic}
+% or
+%  \entry {sortstring}{page}{topic}{subtopic}
+% The texindex program reads in these files and writes files
+% containing these kinds of lines:
+%  \initial {c}
+%     before the first topic whose initial is c
+%  \entry {topic}{pagelist}
+%     for a topic that is used without subtopics
+%  \primary {topic}
+%     for the beginning of a topic that is used with subtopics
+%  \secondary {subtopic}{pagelist}
+%     for each subtopic.
+
+% Define the user-accessible indexing commands
+% @findex, @vindex, @kindex, @cindex.
+
+\def\findex {\fnindex}
+\def\kindex {\kyindex}
+\def\cindex {\cpindex}
+\def\vindex {\vrindex}
+\def\tindex {\tpindex}
+\def\pindex {\pgindex}
+
+\def\cindexsub {\begingroup\obeylines\cindexsub}
+{\obeylines %
+\gdef\cindexsub "#1" #2^^M{\endgroup %
+\dosubind{cp}{#2}{#1}}}
+
+% Define the macros used in formatting output of the sorted index material.
+
+% @printindex causes a particular index (the ??s file) to get printed.
+% It does not print any chapter heading (usually an @unnumbered).
+%
+\parseargdef\printindex{\begingroup
+  \dobreak \chapheadingskip{10000}%
+  %
+  \smallfonts \rm
+  \tolerance = 9500
+  \everypar = {}% don't want the \kern\-parindent from indentation suppression.
+  %
+  % See if the index file exists and is nonempty.
+  % Change catcode of @ here so that if the index file contains
+  % \initial {@}
+  % as its first line, TeX doesn't complain about mismatched braces
+  % (because it thinks @} is a control sequence).
+  \catcode`\@ = 11
+  \openin 1 \jobname.#1s
+  \ifeof 1
+    % \enddoublecolumns gets confused if there is no text in the index,
+    % and it loses the chapter title and the aux file entries for the
+    % index.  The easiest way to prevent this problem is to make sure
+    % there is some text.
+    \putwordIndexNonexistent
+  \else
+    %
+    % If the index file exists but is empty, then \openin leaves \ifeof
+    % false.  We have to make TeX try to read something from the file, so
+    % it can discover if there is anything in it.
+    \read 1 to \temp
+    \ifeof 1
+      \putwordIndexIsEmpty
+    \else
+      % Index files are almost Texinfo source, but we use \ as the escape
+      % character.  It would be better to use @, but that's too big a change
+      % to make right now.
+      \def\indexbackslash{\backslashcurfont}%
+      \catcode`\\ = 0
+      \escapechar = `\\
+      \begindoublecolumns
+      \input \jobname.#1s
+      \enddoublecolumns
+    \fi
+  \fi
+  \closein 1
+\endgroup}
+
+% These macros are used by the sorted index file itself.
+% Change them to control the appearance of the index.
+
+\def\initial#1{{%
+  % Some minor font changes for the special characters.
+  \let\tentt=\sectt \let\tt=\sectt \let\sf=\sectt
+  %
+  % Remove any glue we may have, we'll be inserting our own.
+  \removelastskip
+  %
+  % We like breaks before the index initials, so insert a bonus.
+  \nobreak
+  \vskip 0pt plus 3\baselineskip
+  \penalty 0
+  \vskip 0pt plus -3\baselineskip
+  %
+  % Typeset the initial.  Making this add up to a whole number of
+  % baselineskips increases the chance of the dots lining up from column
+  % to column.  It still won't often be perfect, because of the stretch
+  % we need before each entry, but it's better.
+  %
+  % No shrink because it confuses \balancecolumns.
+  \vskip 1.67\baselineskip plus .5\baselineskip
+  \leftline{\secbf #1}%
+  % Do our best not to break after the initial.
+  \nobreak
+  \vskip .33\baselineskip plus .1\baselineskip
+}}
+
+% \entry typesets a paragraph consisting of the text (#1), dot leaders, and
+% then page number (#2) flushed to the right margin.  It is used for index
+% and table of contents entries.  The paragraph is indented by \leftskip.
+%
+% A straightforward implementation would start like this:
+%	\def\entry#1#2{...
+% But this frozes the catcodes in the argument, and can cause problems to
+% @code, which sets - active.  This problem was fixed by a kludge---
+% ``-'' was active throughout whole index, but this isn't really right.
+%
+% The right solution is to prevent \entry from swallowing the whole text.
+%                                 --kasal, 21nov03
+\def\entry{%
+  \begingroup
+    %
+    % Start a new paragraph if necessary, so our assignments below can't
+    % affect previous text.
+    \par
+    %
+    % Do not fill out the last line with white space.
+    \parfillskip = 0in
+    %
+    % No extra space above this paragraph.
+    \parskip = 0in
+    %
+    % Do not prefer a separate line ending with a hyphen to fewer lines.
+    \finalhyphendemerits = 0
+    %
+    % \hangindent is only relevant when the entry text and page number
+    % don't both fit on one line.  In that case, bob suggests starting the
+    % dots pretty far over on the line.  Unfortunately, a large
+    % indentation looks wrong when the entry text itself is broken across
+    % lines.  So we use a small indentation and put up with long leaders.
+    %
+    % \hangafter is reset to 1 (which is the value we want) at the start
+    % of each paragraph, so we need not do anything with that.
+    \hangindent = 2em
+    %
+    % When the entry text needs to be broken, just fill out the first line
+    % with blank space.
+    \rightskip = 0pt plus1fil
+    %
+    % A bit of stretch before each entry for the benefit of balancing
+    % columns.
+    \vskip 0pt plus1pt
+    %
+    % Swallow the left brace of the text (first parameter):
+    \afterassignment\doentry
+    \let\temp =
+}
+\def\doentry{%
+    \bgroup % Instead of the swallowed brace.
+      \noindent
+      \aftergroup\finishentry
+      % And now comes the text of the entry.
+}
+\def\finishentry#1{%
+    % #1 is the page number.
+    %
+    % The following is kludged to not output a line of dots in the index if
+    % there are no page numbers.  The next person who breaks this will be
+    % cursed by a Unix daemon.
+    \def\tempa{{\rm }}%
+    \def\tempb{#1}%
+    \edef\tempc{\tempa}%
+    \edef\tempd{\tempb}%
+    \ifx\tempc\tempd
+      \ %
+    \else
+      %
+      % If we must, put the page number on a line of its own, and fill out
+      % this line with blank space.  (The \hfil is overwhelmed with the
+      % fill leaders glue in \indexdotfill if the page number does fit.)
+      \hfil\penalty50
+      \null\nobreak\indexdotfill % Have leaders before the page number.
+      %
+      % The `\ ' here is removed by the implicit \unskip that TeX does as
+      % part of (the primitive) \par.  Without it, a spurious underfull
+      % \hbox ensues.
+      \ifpdf
+	\pdfgettoks#1.%
+	\ \the\toksA
+      \else
+	\ #1%
+      \fi
+    \fi
+    \par
+  \endgroup
+}
+
+% Like plain.tex's \dotfill, except uses up at least 1 em.
+\def\indexdotfill{\cleaders
+  \hbox{$\mathsurround=0pt \mkern1.5mu.\mkern1.5mu$}\hskip 1em plus 1fill}
+
+\def\primary #1{\line{#1\hfil}}
+
+\newskip\secondaryindent \secondaryindent=0.5cm
+\def\secondary#1#2{{%
+  \parfillskip=0in
+  \parskip=0in
+  \hangindent=1in
+  \hangafter=1
+  \noindent\hskip\secondaryindent\hbox{#1}\indexdotfill
+  \ifpdf
+    \pdfgettoks#2.\ \the\toksA % The page number ends the paragraph.
+  \else
+    #2
+  \fi
+  \par
+}}
+
+% Define two-column mode, which we use to typeset indexes.
+% Adapted from the TeXbook, page 416, which is to say,
+% the manmac.tex format used to print the TeXbook itself.
+\catcode`\@=11
+
+\newbox\partialpage
+\newdimen\doublecolumnhsize
+
+\def\begindoublecolumns{\begingroup % ended by \enddoublecolumns
+  % Grab any single-column material above us.
+  \output = {%
+    %
+    % Here is a possibility not foreseen in manmac: if we accumulate a
+    % whole lot of material, we might end up calling this \output
+    % routine twice in a row (see the doublecol-lose test, which is
+    % essentially a couple of indexes with @setchapternewpage off).  In
+    % that case we just ship out what is in \partialpage with the normal
+    % output routine.  Generally, \partialpage will be empty when this
+    % runs and this will be a no-op.  See the indexspread.tex test case.
+    \ifvoid\partialpage \else
+      \onepageout{\pagecontents\partialpage}%
+    \fi
+    %
+    \global\setbox\partialpage = \vbox{%
+      % Unvbox the main output page.
+      \unvbox\PAGE
+      \kern-\topskip \kern\baselineskip
+    }%
+  }%
+  \eject % run that output routine to set \partialpage
+  %
+  % Use the double-column output routine for subsequent pages.
+  \output = {\doublecolumnout}%
+  %
+  % Change the page size parameters.  We could do this once outside this
+  % routine, in each of @smallbook, @afourpaper, and the default 8.5x11
+  % format, but then we repeat the same computation.  Repeating a couple
+  % of assignments once per index is clearly meaningless for the
+  % execution time, so we may as well do it in one place.
+  %
+  % First we halve the line length, less a little for the gutter between
+  % the columns.  We compute the gutter based on the line length, so it
+  % changes automatically with the paper format.  The magic constant
+  % below is chosen so that the gutter has the same value (well, +-<1pt)
+  % as it did when we hard-coded it.
+  %
+  % We put the result in a separate register, \doublecolumhsize, so we
+  % can restore it in \pagesofar, after \hsize itself has (potentially)
+  % been clobbered.
+  %
+  \doublecolumnhsize = \hsize
+    \advance\doublecolumnhsize by -.04154\hsize
+    \divide\doublecolumnhsize by 2
+  \hsize = \doublecolumnhsize
+  %
+  % Double the \vsize as well.  (We don't need a separate register here,
+  % since nobody clobbers \vsize.)
+  \vsize = 2\vsize
+}
+
+% The double-column output routine for all double-column pages except
+% the last.
+%
+\def\doublecolumnout{%
+  \splittopskip=\topskip \splitmaxdepth=\maxdepth
+  % Get the available space for the double columns -- the normal
+  % (undoubled) page height minus any material left over from the
+  % previous page.
+  \dimen@ = \vsize
+  \divide\dimen@ by 2
+  \advance\dimen@ by -\ht\partialpage
+  %
+  % box0 will be the left-hand column, box2 the right.
+  \setbox0=\vsplit255 to\dimen@ \setbox2=\vsplit255 to\dimen@
+  \onepageout\pagesofar
+  \unvbox255
+  \penalty\outputpenalty
+}
+%
+% Re-output the contents of the output page -- any previous material,
+% followed by the two boxes we just split, in box0 and box2.
+\def\pagesofar{%
+  \unvbox\partialpage
+  %
+  \hsize = \doublecolumnhsize
+  \wd0=\hsize \wd2=\hsize
+  \hbox to\pagewidth{\box0\hfil\box2}%
+}
+%
+% All done with double columns.
+\def\enddoublecolumns{%
+  \output = {%
+    % Split the last of the double-column material.  Leave it on the
+    % current page, no automatic page break.
+    \balancecolumns
+    %
+    % If we end up splitting too much material for the current page,
+    % though, there will be another page break right after this \output
+    % invocation ends.  Having called \balancecolumns once, we do not
+    % want to call it again.  Therefore, reset \output to its normal
+    % definition right away.  (We hope \balancecolumns will never be
+    % called on to balance too much material, but if it is, this makes
+    % the output somewhat more palatable.)
+    \global\output = {\onepageout{\pagecontents\PAGE}}%
+  }%
+  \eject
+  \endgroup % started in \begindoublecolumns
+  %
+  % \pagegoal was set to the doubled \vsize above, since we restarted
+  % the current page.  We're now back to normal single-column
+  % typesetting, so reset \pagegoal to the normal \vsize (after the
+  % \endgroup where \vsize got restored).
+  \pagegoal = \vsize
+}
+%
+% Called at the end of the double column material.
+\def\balancecolumns{%
+  \setbox0 = \vbox{\unvbox255}% like \box255 but more efficient, see p.120.
+  \dimen@ = \ht0
+  \advance\dimen@ by \topskip
+  \advance\dimen@ by-\baselineskip
+  \divide\dimen@ by 2 % target to split to
+  %debug\message{final 2-column material height=\the\ht0, target=\the\dimen@.}%
+  \splittopskip = \topskip
+  % Loop until we get a decent breakpoint.
+  {%
+    \vbadness = 10000
+    \loop
+      \global\setbox3 = \copy0
+      \global\setbox1 = \vsplit3 to \dimen@
+    \ifdim\ht3>\dimen@
+      \global\advance\dimen@ by 1pt
+    \repeat
+  }%
+  %debug\message{split to \the\dimen@, column heights: \the\ht1, \the\ht3.}%
+  \setbox0=\vbox to\dimen@{\unvbox1}%
+  \setbox2=\vbox to\dimen@{\unvbox3}%
+  %
+  \pagesofar
+}
+\catcode`\@ = \other
+
+
+\message{sectioning,}
+% Chapters, sections, etc.
+
+% \unnumberedno is an oxymoron, of course.  But we count the unnumbered
+% sections so that we can refer to them unambiguously in the pdf
+% outlines by their "section number".  We avoid collisions with chapter
+% numbers by starting them at 10000.  (If a document ever has 10000
+% chapters, we're in trouble anyway, I'm sure.)
+\newcount\unnumberedno \unnumberedno = 10000
+\newcount\chapno
+\newcount\secno        \secno=0
+\newcount\subsecno     \subsecno=0
+\newcount\subsubsecno  \subsubsecno=0
+
+% This counter is funny since it counts through charcodes of letters A, B, ...
+\newcount\appendixno  \appendixno = `\@
+%
+% \def\appendixletter{\char\the\appendixno}
+% We do the following ugly conditional instead of the above simple
+% construct for the sake of pdftex, which needs the actual
+% letter in the expansion, not just typeset.
+%
+\def\appendixletter{%
+  \ifnum\appendixno=`A A%
+  \else\ifnum\appendixno=`B B%
+  \else\ifnum\appendixno=`C C%
+  \else\ifnum\appendixno=`D D%
+  \else\ifnum\appendixno=`E E%
+  \else\ifnum\appendixno=`F F%
+  \else\ifnum\appendixno=`G G%
+  \else\ifnum\appendixno=`H H%
+  \else\ifnum\appendixno=`I I%
+  \else\ifnum\appendixno=`J J%
+  \else\ifnum\appendixno=`K K%
+  \else\ifnum\appendixno=`L L%
+  \else\ifnum\appendixno=`M M%
+  \else\ifnum\appendixno=`N N%
+  \else\ifnum\appendixno=`O O%
+  \else\ifnum\appendixno=`P P%
+  \else\ifnum\appendixno=`Q Q%
+  \else\ifnum\appendixno=`R R%
+  \else\ifnum\appendixno=`S S%
+  \else\ifnum\appendixno=`T T%
+  \else\ifnum\appendixno=`U U%
+  \else\ifnum\appendixno=`V V%
+  \else\ifnum\appendixno=`W W%
+  \else\ifnum\appendixno=`X X%
+  \else\ifnum\appendixno=`Y Y%
+  \else\ifnum\appendixno=`Z Z%
+  % The \the is necessary, despite appearances, because \appendixletter is
+  % expanded while writing the .toc file.  \char\appendixno is not
+  % expandable, thus it is written literally, thus all appendixes come out
+  % with the same letter (or @) in the toc without it.
+  \else\char\the\appendixno
+  \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi
+  \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi}
+
+% Each @chapter defines this as the name of the chapter.
+% page headings and footings can use it.  @section does likewise.
+% However, they are not reliable, because we don't use marks.
+\def\thischapter{}
+\def\thissection{}
+
+\newcount\absseclevel % used to calculate proper heading level
+\newcount\secbase\secbase=0 % @raisesections/@lowersections modify this count
+
+% @raisesections: treat @section as chapter, @subsection as section, etc.
+\def\raisesections{\global\advance\secbase by -1}
+\let\up=\raisesections % original BFox name
+
+% @lowersections: treat @chapter as section, @section as subsection, etc.
+\def\lowersections{\global\advance\secbase by 1}
+\let\down=\lowersections % original BFox name
+
+% we only have subsub.
+\chardef\maxseclevel = 3
+%
+% A numbered section within an unnumbered changes to unnumbered too.
+% To achive this, remember the "biggest" unnum. sec. we are currently in:
+\chardef\unmlevel = \maxseclevel
+%
+% Trace whether the current chapter is an appendix or not:
+% \chapheadtype is "N" or "A", unnumbered chapters are ignored.
+\def\chapheadtype{N}
+
+% Choose a heading macro
+% #1 is heading type
+% #2 is heading level
+% #3 is text for heading
+\def\genhead#1#2#3{%
+  % Compute the abs. sec. level:
+  \absseclevel=#2
+  \advance\absseclevel by \secbase
+  % Make sure \absseclevel doesn't fall outside the range:
+  \ifnum \absseclevel < 0
+    \absseclevel = 0
+  \else
+    \ifnum \absseclevel > 3
+      \absseclevel = 3
+    \fi
+  \fi
+  % The heading type:
+  \def\headtype{#1}%
+  \if \headtype U%
+    \ifnum \absseclevel < \unmlevel
+      \chardef\unmlevel = \absseclevel
+    \fi
+  \else
+    % Check for appendix sections:
+    \ifnum \absseclevel = 0
+      \edef\chapheadtype{\headtype}%
+    \else
+      \if \headtype A\if \chapheadtype N%
+	\errmessage{@appendix... within a non-appendix chapter}%
+      \fi\fi
+    \fi
+    % Check for numbered within unnumbered:
+    \ifnum \absseclevel > \unmlevel
+      \def\headtype{U}%
+    \else
+      \chardef\unmlevel = 3
+    \fi
+  \fi
+  % Now print the heading:
+  \if \headtype U%
+    \ifcase\absseclevel
+	\unnumberedzzz{#3}%
+    \or \unnumberedseczzz{#3}%
+    \or \unnumberedsubseczzz{#3}%
+    \or \unnumberedsubsubseczzz{#3}%
+    \fi
+  \else
+    \if \headtype A%
+      \ifcase\absseclevel
+	  \appendixzzz{#3}%
+      \or \appendixsectionzzz{#3}%
+      \or \appendixsubseczzz{#3}%
+      \or \appendixsubsubseczzz{#3}%
+      \fi
+    \else
+      \ifcase\absseclevel
+	  \chapterzzz{#3}%
+      \or \seczzz{#3}%
+      \or \numberedsubseczzz{#3}%
+      \or \numberedsubsubseczzz{#3}%
+      \fi
+    \fi
+  \fi
+  \suppressfirstparagraphindent
+}
+
+% an interface:
+\def\numhead{\genhead N}
+\def\apphead{\genhead A}
+\def\unnmhead{\genhead U}
+
+% @chapter, @appendix, @unnumbered.  Increment top-level counter, reset
+% all lower-level sectioning counters to zero.
+%
+% Also set \chaplevelprefix, which we prepend to @float sequence numbers
+% (e.g., figures), q.v.  By default (before any chapter), that is empty.
+\let\chaplevelprefix = \empty
+%
+\outer\parseargdef\chapter{\numhead0{#1}} % normally numhead0 calls chapterzzz
+\def\chapterzzz#1{%
+  % section resetting is \global in case the chapter is in a group, such
+  % as an @include file.
+  \global\secno=0 \global\subsecno=0 \global\subsubsecno=0
+    \global\advance\chapno by 1
+  %
+  % Used for \float.
+  \gdef\chaplevelprefix{\the\chapno.}%
+  \resetallfloatnos
+  %
+  \message{\putwordChapter\space \the\chapno}%
+  %
+  % Write the actual heading.
+  \chapmacro{#1}{Ynumbered}{\the\chapno}%
+  %
+  % So @section and the like are numbered underneath this chapter.
+  \global\let\section = \numberedsec
+  \global\let\subsection = \numberedsubsec
+  \global\let\subsubsection = \numberedsubsubsec
+}
+
+\outer\parseargdef\appendix{\apphead0{#1}} % normally apphead0 calls appendixzzz
+\def\appendixzzz#1{%
+  \global\secno=0 \global\subsecno=0 \global\subsubsecno=0
+    \global\advance\appendixno by 1
+  \gdef\chaplevelprefix{\appendixletter.}%
+  \resetallfloatnos
+  %
+  \def\appendixnum{\putwordAppendix\space \appendixletter}%
+  \message{\appendixnum}%
+  %
+  \chapmacro{#1}{Yappendix}{\appendixletter}%
+  %
+  \global\let\section = \appendixsec
+  \global\let\subsection = \appendixsubsec
+  \global\let\subsubsection = \appendixsubsubsec
+}
+
+\outer\parseargdef\unnumbered{\unnmhead0{#1}} % normally unnmhead0 calls unnumberedzzz
+\def\unnumberedzzz#1{%
+  \global\secno=0 \global\subsecno=0 \global\subsubsecno=0
+    \global\advance\unnumberedno by 1
+  %
+  % Since an unnumbered has no number, no prefix for figures.
+  \global\let\chaplevelprefix = \empty
+  \resetallfloatnos
+  %
+  % This used to be simply \message{#1}, but TeX fully expands the
+  % argument to \message.  Therefore, if #1 contained @-commands, TeX
+  % expanded them.  For example, in `@unnumbered The @cite{Book}', TeX
+  % expanded @cite (which turns out to cause errors because \cite is meant
+  % to be executed, not expanded).
+  %
+  % Anyway, we don't want the fully-expanded definition of @cite to appear
+  % as a result of the \message, we just want `@cite' itself.  We use
+  % \the<toks register> to achieve this: TeX expands \the<toks> only once,
+  % simply yielding the contents of <toks register>.  (We also do this for
+  % the toc entries.)
+  \toks0 = {#1}%
+  \message{(\the\toks0)}%
+  %
+  \chapmacro{#1}{Ynothing}{\the\unnumberedno}%
+  %
+  \global\let\section = \unnumberedsec
+  \global\let\subsection = \unnumberedsubsec
+  \global\let\subsubsection = \unnumberedsubsubsec
+}
+
+% @centerchap is like @unnumbered, but the heading is centered.
+\outer\parseargdef\centerchap{%
+  % Well, we could do the following in a group, but that would break
+  % an assumption that \chapmacro is called at the outermost level.
+  % Thus we are safer this way:		--kasal, 24feb04
+  \let\centerparametersmaybe = \centerparameters
+  \unnmhead0{#1}%
+  \let\centerparametersmaybe = \relax
+}
+
+% @top is like @unnumbered.
+\let\top\unnumbered
+
+% Sections.
+\outer\parseargdef\numberedsec{\numhead1{#1}} % normally calls seczzz
+\def\seczzz#1{%
+  \global\subsecno=0 \global\subsubsecno=0  \global\advance\secno by 1
+  \sectionheading{#1}{sec}{Ynumbered}{\the\chapno.\the\secno}%
+}
+
+\outer\parseargdef\appendixsection{\apphead1{#1}} % normally calls appendixsectionzzz
+\def\appendixsectionzzz#1{%
+  \global\subsecno=0 \global\subsubsecno=0  \global\advance\secno by 1
+  \sectionheading{#1}{sec}{Yappendix}{\appendixletter.\the\secno}%
+}
+\let\appendixsec\appendixsection
+
+\outer\parseargdef\unnumberedsec{\unnmhead1{#1}} % normally calls unnumberedseczzz
+\def\unnumberedseczzz#1{%
+  \global\subsecno=0 \global\subsubsecno=0  \global\advance\secno by 1
+  \sectionheading{#1}{sec}{Ynothing}{\the\unnumberedno.\the\secno}%
+}
+
+% Subsections.
+\outer\parseargdef\numberedsubsec{\numhead2{#1}} % normally calls numberedsubseczzz
+\def\numberedsubseczzz#1{%
+  \global\subsubsecno=0  \global\advance\subsecno by 1
+  \sectionheading{#1}{subsec}{Ynumbered}{\the\chapno.\the\secno.\the\subsecno}%
+}
+
+\outer\parseargdef\appendixsubsec{\apphead2{#1}} % normally calls appendixsubseczzz
+\def\appendixsubseczzz#1{%
+  \global\subsubsecno=0  \global\advance\subsecno by 1
+  \sectionheading{#1}{subsec}{Yappendix}%
+                 {\appendixletter.\the\secno.\the\subsecno}%
+}
+
+\outer\parseargdef\unnumberedsubsec{\unnmhead2{#1}} %normally calls unnumberedsubseczzz
+\def\unnumberedsubseczzz#1{%
+  \global\subsubsecno=0  \global\advance\subsecno by 1
+  \sectionheading{#1}{subsec}{Ynothing}%
+                 {\the\unnumberedno.\the\secno.\the\subsecno}%
+}
+
+% Subsubsections.
+\outer\parseargdef\numberedsubsubsec{\numhead3{#1}} % normally numberedsubsubseczzz
+\def\numberedsubsubseczzz#1{%
+  \global\advance\subsubsecno by 1
+  \sectionheading{#1}{subsubsec}{Ynumbered}%
+                 {\the\chapno.\the\secno.\the\subsecno.\the\subsubsecno}%
+}
+
+\outer\parseargdef\appendixsubsubsec{\apphead3{#1}} % normally appendixsubsubseczzz
+\def\appendixsubsubseczzz#1{%
+  \global\advance\subsubsecno by 1
+  \sectionheading{#1}{subsubsec}{Yappendix}%
+                 {\appendixletter.\the\secno.\the\subsecno.\the\subsubsecno}%
+}
+
+\outer\parseargdef\unnumberedsubsubsec{\unnmhead3{#1}} %normally unnumberedsubsubseczzz
+\def\unnumberedsubsubseczzz#1{%
+  \global\advance\subsubsecno by 1
+  \sectionheading{#1}{subsubsec}{Ynothing}%
+                 {\the\unnumberedno.\the\secno.\the\subsecno.\the\subsubsecno}%
+}
+
+% These macros control what the section commands do, according
+% to what kind of chapter we are in (ordinary, appendix, or unnumbered).
+% Define them by default for a numbered chapter.
+\let\section = \numberedsec
+\let\subsection = \numberedsubsec
+\let\subsubsection = \numberedsubsubsec
+
+% Define @majorheading, @heading and @subheading
+
+% NOTE on use of \vbox for chapter headings, section headings, and such:
+%       1) We use \vbox rather than the earlier \line to permit
+%          overlong headings to fold.
+%       2) \hyphenpenalty is set to 10000 because hyphenation in a
+%          heading is obnoxious; this forbids it.
+%       3) Likewise, headings look best if no \parindent is used, and
+%          if justification is not attempted.  Hence \raggedright.
+
+
+\def\majorheading{%
+  {\advance\chapheadingskip by 10pt \chapbreak }%
+  \parsearg\chapheadingzzz
+}
+
+\def\chapheading{\chapbreak \parsearg\chapheadingzzz}
+\def\chapheadingzzz#1{%
+  {\chapfonts \vbox{\hyphenpenalty=10000\tolerance=5000
+                    \parindent=0pt\raggedright
+                    \rm #1\hfill}}%
+  \bigskip \par\penalty 200\relax
+  \suppressfirstparagraphindent
+}
+
+% @heading, @subheading, @subsubheading.
+\parseargdef\heading{\sectionheading{#1}{sec}{Yomitfromtoc}{}
+  \suppressfirstparagraphindent}
+\parseargdef\subheading{\sectionheading{#1}{subsec}{Yomitfromtoc}{}
+  \suppressfirstparagraphindent}
+\parseargdef\subsubheading{\sectionheading{#1}{subsubsec}{Yomitfromtoc}{}
+  \suppressfirstparagraphindent}
+
+% These macros generate a chapter, section, etc. heading only
+% (including whitespace, linebreaking, etc. around it),
+% given all the information in convenient, parsed form.
+
+%%% Args are the skip and penalty (usually negative)
+\def\dobreak#1#2{\par\ifdim\lastskip<#1\removelastskip\penalty#2\vskip#1\fi}
+
+%%% Define plain chapter starts, and page on/off switching for it
+% Parameter controlling skip before chapter headings (if needed)
+
+\newskip\chapheadingskip
+
+\def\chapbreak{\dobreak \chapheadingskip {-4000}}
+\def\chappager{\par\vfill\supereject}
+\def\chapoddpage{\chappager \ifodd\pageno \else \hbox to 0pt{} \chappager\fi}
+
+\def\setchapternewpage #1 {\csname CHAPPAG#1\endcsname}
+
+\def\CHAPPAGoff{%
+\global\let\contentsalignmacro = \chappager
+\global\let\pchapsepmacro=\chapbreak
+\global\let\pagealignmacro=\chappager}
+
+\def\CHAPPAGon{%
+\global\let\contentsalignmacro = \chappager
+\global\let\pchapsepmacro=\chappager
+\global\let\pagealignmacro=\chappager
+\global\def\HEADINGSon{\HEADINGSsingle}}
+
+\def\CHAPPAGodd{%
+\global\let\contentsalignmacro = \chapoddpage
+\global\let\pchapsepmacro=\chapoddpage
+\global\let\pagealignmacro=\chapoddpage
+\global\def\HEADINGSon{\HEADINGSdouble}}
+
+\CHAPPAGon
+
+% Chapter opening.
+%
+% #1 is the text, #2 is the section type (Ynumbered, Ynothing,
+% Yappendix, Yomitfromtoc), #3 the chapter number.
+%
+% To test against our argument.
+\def\Ynothingkeyword{Ynothing}
+\def\Yomitfromtockeyword{Yomitfromtoc}
+\def\Yappendixkeyword{Yappendix}
+%
+\def\chapmacro#1#2#3{%
+  \pchapsepmacro
+  {%
+    \chapfonts \rm
+    %
+    % Have to define \thissection before calling \donoderef, because the
+    % xref code eventually uses it.  On the other hand, it has to be called
+    % after \pchapsepmacro, or the headline will change too soon.
+    \gdef\thissection{#1}%
+    \gdef\thischaptername{#1}%
+    %
+    % Only insert the separating space if we have a chapter/appendix
+    % number, and don't print the unnumbered ``number''.
+    \def\temptype{#2}%
+    \ifx\temptype\Ynothingkeyword
+      \setbox0 = \hbox{}%
+      \def\toctype{unnchap}%
+      \gdef\thischapternum{}%
+      \gdef\thischapter{#1}%
+    \else\ifx\temptype\Yomitfromtockeyword
+      \setbox0 = \hbox{}% contents like unnumbered, but no toc entry
+      \def\toctype{omit}%
+      \gdef\thischapternum{}%
+      \gdef\thischapter{}%
+    \else\ifx\temptype\Yappendixkeyword
+      \setbox0 = \hbox{\putwordAppendix{} #3\enspace}%
+      \def\toctype{app}%
+      \xdef\thischapternum{\appendixletter}%
+      % We don't substitute the actual chapter name into \thischapter
+      % because we don't want its macros evaluated now.  And we don't
+      % use \thissection because that changes with each section.
+      %
+      \xdef\thischapter{\putwordAppendix{} \appendixletter:
+                        \noexpand\thischaptername}%
+    \else
+      \setbox0 = \hbox{#3\enspace}%
+      \def\toctype{numchap}%
+      \xdef\thischapternum{\the\chapno}%
+      \xdef\thischapter{\putwordChapter{} \the\chapno:
+                        \noexpand\thischaptername}%
+    \fi\fi\fi
+    %
+    % Write the toc entry for this chapter.  Must come before the
+    % \donoderef, because we include the current node name in the toc
+    % entry, and \donoderef resets it to empty.
+    \writetocentry{\toctype}{#1}{#3}%
+    %
+    % For pdftex, we have to write out the node definition (aka, make
+    % the pdfdest) after any page break, but before the actual text has
+    % been typeset.  If the destination for the pdf outline is after the
+    % text, then jumping from the outline may wind up with the text not
+    % being visible, for instance under high magnification.
+    \donoderef{#2}%
+    %
+    % Typeset the actual heading.
+    \vbox{\hyphenpenalty=10000 \tolerance=5000 \parindent=0pt \raggedright
+          \hangindent=\wd0 \centerparametersmaybe
+          \unhbox0 #1\par}%
+  }%
+  \nobreak\bigskip % no page break after a chapter title
+  \nobreak
+}
+
+% @centerchap -- centered and unnumbered.
+\let\centerparametersmaybe = \relax
+\def\centerparameters{%
+  \advance\rightskip by 3\rightskip
+  \leftskip = \rightskip
+  \parfillskip = 0pt
+}
+
+
+% I don't think this chapter style is supported any more, so I'm not
+% updating it with the new noderef stuff.  We'll see.  --karl, 11aug03.
+%
+\def\setchapterstyle #1 {\csname CHAPF#1\endcsname}
+%
+\def\unnchfopen #1{%
+\chapoddpage {\chapfonts \vbox{\hyphenpenalty=10000\tolerance=5000
+                       \parindent=0pt\raggedright
+                       \rm #1\hfill}}\bigskip \par\nobreak
+}
+\def\chfopen #1#2{\chapoddpage {\chapfonts
+\vbox to 3in{\vfil \hbox to\hsize{\hfil #2} \hbox to\hsize{\hfil #1} \vfil}}%
+\par\penalty 5000 %
+}
+\def\centerchfopen #1{%
+\chapoddpage {\chapfonts \vbox{\hyphenpenalty=10000\tolerance=5000
+                       \parindent=0pt
+                       \hfill {\rm #1}\hfill}}\bigskip \par\nobreak
+}
+\def\CHAPFopen{%
+  \global\let\chapmacro=\chfopen
+  \global\let\centerchapmacro=\centerchfopen}
+
+
+% Section titles.  These macros combine the section number parts and
+% call the generic \sectionheading to do the printing.
+%
+\newskip\secheadingskip
+\def\secheadingbreak{\dobreak \secheadingskip{-1000}}
+
+% Subsection titles.
+\newskip\subsecheadingskip
+\def\subsecheadingbreak{\dobreak \subsecheadingskip{-500}}
+
+% Subsubsection titles.
+\def\subsubsecheadingskip{\subsecheadingskip}
+\def\subsubsecheadingbreak{\subsecheadingbreak}
+
+
+% Print any size, any type, section title.
+%
+% #1 is the text, #2 is the section level (sec/subsec/subsubsec), #3 is
+% the section type for xrefs (Ynumbered, Ynothing, Yappendix), #4 is the
+% section number.
+%
+\def\sectionheading#1#2#3#4{%
+  {%
+    % Switch to the right set of fonts.
+    \csname #2fonts\endcsname \rm
+    %
+    % Insert space above the heading.
+    \csname #2headingbreak\endcsname
+    %
+    % Only insert the space after the number if we have a section number.
+    \def\sectionlevel{#2}%
+    \def\temptype{#3}%
+    %
+    \ifx\temptype\Ynothingkeyword
+      \setbox0 = \hbox{}%
+      \def\toctype{unn}%
+      \gdef\thissection{#1}%
+    \else\ifx\temptype\Yomitfromtockeyword
+      % for @headings -- no section number, don't include in toc,
+      % and don't redefine \thissection.
+      \setbox0 = \hbox{}%
+      \def\toctype{omit}%
+      \let\sectionlevel=\empty
+    \else\ifx\temptype\Yappendixkeyword
+      \setbox0 = \hbox{#4\enspace}%
+      \def\toctype{app}%
+      \gdef\thissection{#1}%
+    \else
+      \setbox0 = \hbox{#4\enspace}%
+      \def\toctype{num}%
+      \gdef\thissection{#1}%
+    \fi\fi\fi
+    %
+    % Write the toc entry (before \donoderef).  See comments in \chapmacro.
+    \writetocentry{\toctype\sectionlevel}{#1}{#4}%
+    %
+    % Write the node reference (= pdf destination for pdftex).
+    % Again, see comments in \chapmacro.
+    \donoderef{#3}%
+    %
+    % Interline glue will be inserted when the vbox is completed.
+    % That glue will be a valid breakpoint for the page, since it'll be
+    % preceded by a whatsit (usually from the \donoderef, or from the
+    % \writetocentry if there was no node).  We don't want to allow that
+    % break, since then the whatsits could end up on page n while the
+    % section is on page n+1, thus toc/etc. are wrong.  Debian bug 276000.
+    \nobreak
+    %
+    % Output the actual section heading.
+    \vbox{\hyphenpenalty=10000 \tolerance=5000 \parindent=0pt \raggedright
+          \hangindent=\wd0  % zero if no section number
+          \unhbox0 #1}%
+  }%
+  % Add extra space after the heading -- half of whatever came above it.
+  % Don't allow stretch, though.
+  \kern .5 \csname #2headingskip\endcsname
+  %
+  % Do not let the kern be a potential breakpoint, as it would be if it
+  % was followed by glue.
+  \nobreak
+  %
+  % We'll almost certainly start a paragraph next, so don't let that
+  % glue accumulate.  (Not a breakpoint because it's preceded by a
+  % discardable item.)
+  \vskip-\parskip
+  % 
+  % This is purely so the last item on the list is a known \penalty >
+  % 10000.  This is so \startdefun can avoid allowing breakpoints after
+  % section headings.  Otherwise, it would insert a valid breakpoint between:
+  % 
+  %   @section sec-whatever
+  %   @deffn def-whatever
+  \penalty 10001
+}
+
+
+\message{toc,}
+% Table of contents.
+\newwrite\tocfile
+
+% Write an entry to the toc file, opening it if necessary.
+% Called from @chapter, etc.
+%
+% Example usage: \writetocentry{sec}{Section Name}{\the\chapno.\the\secno}
+% We append the current node name (if any) and page number as additional
+% arguments for the \{chap,sec,...}entry macros which will eventually
+% read this.  The node name is used in the pdf outlines as the
+% destination to jump to.
+%
+% We open the .toc file for writing here instead of at @setfilename (or
+% any other fixed time) so that @contents can be anywhere in the document.
+% But if #1 is `omit', then we don't do anything.  This is used for the
+% table of contents chapter openings themselves.
+%
+\newif\iftocfileopened
+\def\omitkeyword{omit}%
+%
+\def\writetocentry#1#2#3{%
+  \edef\writetoctype{#1}%
+  \ifx\writetoctype\omitkeyword \else
+    \iftocfileopened\else
+      \immediate\openout\tocfile = \jobname.toc
+      \global\tocfileopenedtrue
+    \fi
+    %
+    \iflinks
+      {\atdummies
+       \edef\temp{%
+         \write\tocfile{@#1entry{#2}{#3}{\lastnode}{\noexpand\folio}}}%
+       \temp
+      }%
+    \fi
+  \fi
+  %
+  % Tell \shipout to create a pdf destination on each page, if we're
+  % writing pdf.  These are used in the table of contents.  We can't
+  % just write one on every page because the title pages are numbered
+  % 1 and 2 (the page numbers aren't printed), and so are the first
+  % two pages of the document.  Thus, we'd have two destinations named
+  % `1', and two named `2'.
+  \ifpdf \global\pdfmakepagedesttrue \fi
+}
+
+
+% These characters do not print properly in the Computer Modern roman
+% fonts, so we must take special care.  This is more or less redundant
+% with the Texinfo input format setup at the end of this file.
+% 
+\def\activecatcodes{%
+  \catcode`\"=\active
+  \catcode`\$=\active
+  \catcode`\<=\active
+  \catcode`\>=\active
+  \catcode`\\=\active
+  \catcode`\^=\active
+  \catcode`\_=\active
+  \catcode`\|=\active
+  \catcode`\~=\active
+}
+
+
+% Read the toc file, which is essentially Texinfo input.
+\def\readtocfile{%
+  \setupdatafile
+  \activecatcodes
+  \input \jobname.toc
+}
+
+\newskip\contentsrightmargin \contentsrightmargin=1in
+\newcount\savepageno
+\newcount\lastnegativepageno \lastnegativepageno = -1
+
+% Prepare to read what we've written to \tocfile.
+%
+\def\startcontents#1{%
+  % If @setchapternewpage on, and @headings double, the contents should
+  % start on an odd page, unlike chapters.  Thus, we maintain
+  % \contentsalignmacro in parallel with \pagealignmacro.
+  % From: Torbjorn Granlund <tege@matematik.su.se>
+  \contentsalignmacro
+  \immediate\closeout\tocfile
+  %
+  % Don't need to put `Contents' or `Short Contents' in the headline.
+  % It is abundantly clear what they are.
+  \def\thischapter{}%
+  \chapmacro{#1}{Yomitfromtoc}{}%
+  %
+  \savepageno = \pageno
+  \begingroup                  % Set up to handle contents files properly.
+    \raggedbottom              % Worry more about breakpoints than the bottom.
+    \advance\hsize by -\contentsrightmargin % Don't use the full line length.
+    %
+    % Roman numerals for page numbers.
+    \ifnum \pageno>0 \global\pageno = \lastnegativepageno \fi
+}
+
+
+% Normal (long) toc.
+\def\contents{%
+  \startcontents{\putwordTOC}%
+    \openin 1 \jobname.toc
+    \ifeof 1 \else
+      \readtocfile
+    \fi
+    \vfill \eject
+    \contentsalignmacro % in case @setchapternewpage odd is in effect
+    \ifeof 1 \else
+      \pdfmakeoutlines
+    \fi
+    \closein 1
+  \endgroup
+  \lastnegativepageno = \pageno
+  \global\pageno = \savepageno
+}
+
+% And just the chapters.
+\def\summarycontents{%
+  \startcontents{\putwordShortTOC}%
+    %
+    \let\numchapentry = \shortchapentry
+    \let\appentry = \shortchapentry
+    \let\unnchapentry = \shortunnchapentry
+    % We want a true roman here for the page numbers.
+    \secfonts
+    \let\rm=\shortcontrm \let\bf=\shortcontbf
+    \let\sl=\shortcontsl \let\tt=\shortconttt
+    \rm
+    \hyphenpenalty = 10000
+    \advance\baselineskip by 1pt % Open it up a little.
+    \def\numsecentry##1##2##3##4{}
+    \let\appsecentry = \numsecentry
+    \let\unnsecentry = \numsecentry
+    \let\numsubsecentry = \numsecentry
+    \let\appsubsecentry = \numsecentry
+    \let\unnsubsecentry = \numsecentry
+    \let\numsubsubsecentry = \numsecentry
+    \let\appsubsubsecentry = \numsecentry
+    \let\unnsubsubsecentry = \numsecentry
+    \openin 1 \jobname.toc
+    \ifeof 1 \else
+      \readtocfile
+    \fi
+    \closein 1
+    \vfill \eject
+    \contentsalignmacro % in case @setchapternewpage odd is in effect
+  \endgroup
+  \lastnegativepageno = \pageno
+  \global\pageno = \savepageno
+}
+\let\shortcontents = \summarycontents
+
+% Typeset the label for a chapter or appendix for the short contents.
+% The arg is, e.g., `A' for an appendix, or `3' for a chapter.
+%
+\def\shortchaplabel#1{%
+  % This space should be enough, since a single number is .5em, and the
+  % widest letter (M) is 1em, at least in the Computer Modern fonts.
+  % But use \hss just in case.
+  % (This space doesn't include the extra space that gets added after
+  % the label; that gets put in by \shortchapentry above.)
+  %
+  % We'd like to right-justify chapter numbers, but that looks strange
+  % with appendix letters.  And right-justifying numbers and
+  % left-justifying letters looks strange when there is less than 10
+  % chapters.  Have to read the whole toc once to know how many chapters
+  % there are before deciding ...
+  \hbox to 1em{#1\hss}%
+}
+
+% These macros generate individual entries in the table of contents.
+% The first argument is the chapter or section name.
+% The last argument is the page number.
+% The arguments in between are the chapter number, section number, ...
+
+% Chapters, in the main contents.
+\def\numchapentry#1#2#3#4{\dochapentry{#2\labelspace#1}{#4}}
+%
+% Chapters, in the short toc.
+% See comments in \dochapentry re vbox and related settings.
+\def\shortchapentry#1#2#3#4{%
+  \tocentry{\shortchaplabel{#2}\labelspace #1}{\doshortpageno\bgroup#4\egroup}%
+}
+
+% Appendices, in the main contents.
+% Need the word Appendix, and a fixed-size box.
+%
+\def\appendixbox#1{%
+  % We use M since it's probably the widest letter.
+  \setbox0 = \hbox{\putwordAppendix{} M}%
+  \hbox to \wd0{\putwordAppendix{} #1\hss}}
+%
+\def\appentry#1#2#3#4{\dochapentry{\appendixbox{#2}\labelspace#1}{#4}}
+
+% Unnumbered chapters.
+\def\unnchapentry#1#2#3#4{\dochapentry{#1}{#4}}
+\def\shortunnchapentry#1#2#3#4{\tocentry{#1}{\doshortpageno\bgroup#4\egroup}}
+
+% Sections.
+\def\numsecentry#1#2#3#4{\dosecentry{#2\labelspace#1}{#4}}
+\let\appsecentry=\numsecentry
+\def\unnsecentry#1#2#3#4{\dosecentry{#1}{#4}}
+
+% Subsections.
+\def\numsubsecentry#1#2#3#4{\dosubsecentry{#2\labelspace#1}{#4}}
+\let\appsubsecentry=\numsubsecentry
+\def\unnsubsecentry#1#2#3#4{\dosubsecentry{#1}{#4}}
+
+% And subsubsections.
+\def\numsubsubsecentry#1#2#3#4{\dosubsubsecentry{#2\labelspace#1}{#4}}
+\let\appsubsubsecentry=\numsubsubsecentry
+\def\unnsubsubsecentry#1#2#3#4{\dosubsubsecentry{#1}{#4}}
+
+% This parameter controls the indentation of the various levels.
+% Same as \defaultparindent.
+\newdimen\tocindent \tocindent = 15pt
+
+% Now for the actual typesetting. In all these, #1 is the text and #2 is the
+% page number.
+%
+% If the toc has to be broken over pages, we want it to be at chapters
+% if at all possible; hence the \penalty.
+\def\dochapentry#1#2{%
+   \penalty-300 \vskip1\baselineskip plus.33\baselineskip minus.25\baselineskip
+   \begingroup
+     \chapentryfonts
+     \tocentry{#1}{\dopageno\bgroup#2\egroup}%
+   \endgroup
+   \nobreak\vskip .25\baselineskip plus.1\baselineskip
+}
+
+\def\dosecentry#1#2{\begingroup
+  \secentryfonts \leftskip=\tocindent
+  \tocentry{#1}{\dopageno\bgroup#2\egroup}%
+\endgroup}
+
+\def\dosubsecentry#1#2{\begingroup
+  \subsecentryfonts \leftskip=2\tocindent
+  \tocentry{#1}{\dopageno\bgroup#2\egroup}%
+\endgroup}
+
+\def\dosubsubsecentry#1#2{\begingroup
+  \subsubsecentryfonts \leftskip=3\tocindent
+  \tocentry{#1}{\dopageno\bgroup#2\egroup}%
+\endgroup}
+
+% We use the same \entry macro as for the index entries.
+\let\tocentry = \entry
+
+% Space between chapter (or whatever) number and the title.
+\def\labelspace{\hskip1em \relax}
+
+\def\dopageno#1{{\rm #1}}
+\def\doshortpageno#1{{\rm #1}}
+
+\def\chapentryfonts{\secfonts \rm}
+\def\secentryfonts{\textfonts}
+\def\subsecentryfonts{\textfonts}
+\def\subsubsecentryfonts{\textfonts}
+
+
+\message{environments,}
+% @foo ... @end foo.
+
+% @point{}, @result{}, @expansion{}, @print{}, @equiv{}.
+%
+% Since these characters are used in examples, it should be an even number of
+% \tt widths. Each \tt character is 1en, so two makes it 1em.
+%
+\def\point{$\star$}
+\def\result{\leavevmode\raise.15ex\hbox to 1em{\hfil$\Rightarrow$\hfil}}
+\def\expansion{\leavevmode\raise.1ex\hbox to 1em{\hfil$\mapsto$\hfil}}
+\def\print{\leavevmode\lower.1ex\hbox to 1em{\hfil$\dashv$\hfil}}
+\def\equiv{\leavevmode\lower.1ex\hbox to 1em{\hfil$\ptexequiv$\hfil}}
+
+% The @error{} command.
+% Adapted from the TeXbook's \boxit.
+%
+\newbox\errorbox
+%
+{\tentt \global\dimen0 = 3em}% Width of the box.
+\dimen2 = .55pt % Thickness of rules
+% The text. (`r' is open on the right, `e' somewhat less so on the left.)
+\setbox0 = \hbox{\kern-.75pt \reducedsf error\kern-1.5pt}
+%
+\setbox\errorbox=\hbox to \dimen0{\hfil
+   \hsize = \dimen0 \advance\hsize by -5.8pt % Space to left+right.
+   \advance\hsize by -2\dimen2 % Rules.
+   \vbox{%
+      \hrule height\dimen2
+      \hbox{\vrule width\dimen2 \kern3pt          % Space to left of text.
+         \vtop{\kern2.4pt \box0 \kern2.4pt}% Space above/below.
+         \kern3pt\vrule width\dimen2}% Space to right.
+      \hrule height\dimen2}
+    \hfil}
+%
+\def\error{\leavevmode\lower.7ex\copy\errorbox}
+
+% @tex ... @end tex    escapes into raw Tex temporarily.
+% One exception: @ is still an escape character, so that @end tex works.
+% But \@ or @@ will get a plain tex @ character.
+
+\envdef\tex{%
+  \catcode `\\=0 \catcode `\{=1 \catcode `\}=2
+  \catcode `\$=3 \catcode `\&=4 \catcode `\#=6
+  \catcode `\^=7 \catcode `\_=8 \catcode `\~=\active \let~=\tie
+  \catcode `\%=14
+  \catcode `\+=\other
+  \catcode `\"=\other
+  \catcode `\|=\other
+  \catcode `\<=\other
+  \catcode `\>=\other
+  \escapechar=`\\
+  %
+  \let\b=\ptexb
+  \let\bullet=\ptexbullet
+  \let\c=\ptexc
+  \let\,=\ptexcomma
+  \let\.=\ptexdot
+  \let\dots=\ptexdots
+  \let\equiv=\ptexequiv
+  \let\!=\ptexexclam
+  \let\i=\ptexi
+  \let\indent=\ptexindent
+  \let\noindent=\ptexnoindent
+  \let\{=\ptexlbrace
+  \let\+=\tabalign
+  \let\}=\ptexrbrace
+  \let\/=\ptexslash
+  \let\*=\ptexstar
+  \let\t=\ptext
+  \let\frenchspacing=\plainfrenchspacing
+  %
+  \def\endldots{\mathinner{\ldots\ldots\ldots\ldots}}%
+  \def\enddots{\relax\ifmmode\endldots\else$\mathsurround=0pt \endldots\,$\fi}%
+  \def\@{@}%
+}
+% There is no need to define \Etex.
+
+% Define @lisp ... @end lisp.
+% @lisp environment forms a group so it can rebind things,
+% including the definition of @end lisp (which normally is erroneous).
+
+% Amount to narrow the margins by for @lisp.
+\newskip\lispnarrowing \lispnarrowing=0.4in
+
+% This is the definition that ^^M gets inside @lisp, @example, and other
+% such environments.  \null is better than a space, since it doesn't
+% have any width.
+\def\lisppar{\null\endgraf}
+
+% This space is always present above and below environments.
+\newskip\envskipamount \envskipamount = 0pt
+
+% Make spacing and below environment symmetrical.  We use \parskip here
+% to help in doing that, since in @example-like environments \parskip
+% is reset to zero; thus the \afterenvbreak inserts no space -- but the
+% start of the next paragraph will insert \parskip.
+%
+\def\aboveenvbreak{{%
+  % =10000 instead of <10000 because of a special case in \itemzzz and
+  % \sectionheading, q.v.
+  \ifnum \lastpenalty=10000 \else
+    \advance\envskipamount by \parskip
+    \endgraf
+    \ifdim\lastskip<\envskipamount
+      \removelastskip
+      % it's not a good place to break if the last penalty was \nobreak
+      % or better ...
+      \ifnum\lastpenalty<10000 \penalty-50 \fi
+      \vskip\envskipamount
+    \fi
+  \fi
+}}
+
+\let\afterenvbreak = \aboveenvbreak
+
+% \nonarrowing is a flag.  If "set", @lisp etc don't narrow margins; it will
+% also clear it, so that its embedded environments do the narrowing again.
+\let\nonarrowing=\relax
+
+% @cartouche ... @end cartouche: draw rectangle w/rounded corners around
+% environment contents.
+\font\circle=lcircle10
+\newdimen\circthick
+\newdimen\cartouter\newdimen\cartinner
+\newskip\normbskip\newskip\normpskip\newskip\normlskip
+\circthick=\fontdimen8\circle
+%
+\def\ctl{{\circle\char'013\hskip -6pt}}% 6pt from pl file: 1/2charwidth
+\def\ctr{{\hskip 6pt\circle\char'010}}
+\def\cbl{{\circle\char'012\hskip -6pt}}
+\def\cbr{{\hskip 6pt\circle\char'011}}
+\def\carttop{\hbox to \cartouter{\hskip\lskip
+        \ctl\leaders\hrule height\circthick\hfil\ctr
+        \hskip\rskip}}
+\def\cartbot{\hbox to \cartouter{\hskip\lskip
+        \cbl\leaders\hrule height\circthick\hfil\cbr
+        \hskip\rskip}}
+%
+\newskip\lskip\newskip\rskip
+
+\envdef\cartouche{%
+  \ifhmode\par\fi  % can't be in the midst of a paragraph.
+  \startsavinginserts
+  \lskip=\leftskip \rskip=\rightskip
+  \leftskip=0pt\rightskip=0pt % we want these *outside*.
+  \cartinner=\hsize \advance\cartinner by-\lskip
+  \advance\cartinner by-\rskip
+  \cartouter=\hsize
+  \advance\cartouter by 18.4pt	% allow for 3pt kerns on either
+				% side, and for 6pt waste from
+				% each corner char, and rule thickness
+  \normbskip=\baselineskip \normpskip=\parskip \normlskip=\lineskip
+  % Flag to tell @lisp, etc., not to narrow margin.
+  \let\nonarrowing = t%
+  \vbox\bgroup
+      \baselineskip=0pt\parskip=0pt\lineskip=0pt
+      \carttop
+      \hbox\bgroup
+	  \hskip\lskip
+	  \vrule\kern3pt
+	  \vbox\bgroup
+	      \kern3pt
+	      \hsize=\cartinner
+	      \baselineskip=\normbskip
+	      \lineskip=\normlskip
+	      \parskip=\normpskip
+	      \vskip -\parskip
+	      \comment % For explanation, see the end of \def\group.
+}
+\def\Ecartouche{%
+              \ifhmode\par\fi
+	      \kern3pt
+	  \egroup
+	  \kern3pt\vrule
+	  \hskip\rskip
+      \egroup
+      \cartbot
+  \egroup
+  \checkinserts
+}
+
+
+% This macro is called at the beginning of all the @example variants,
+% inside a group.
+\def\nonfillstart{%
+  \aboveenvbreak
+  \hfuzz = 12pt % Don't be fussy
+  \sepspaces % Make spaces be word-separators rather than space tokens.
+  \let\par = \lisppar % don't ignore blank lines
+  \obeylines % each line of input is a line of output
+  \parskip = 0pt
+  \parindent = 0pt
+  \emergencystretch = 0pt % don't try to avoid overfull boxes
+  \ifx\nonarrowing\relax
+    \advance \leftskip by \lispnarrowing
+    \exdentamount=\lispnarrowing
+  \else
+    \let\nonarrowing = \relax
+  \fi
+  \let\exdent=\nofillexdent
+}
+
+% If you want all examples etc. small: @set dispenvsize small.
+% If you want even small examples the full size: @set dispenvsize nosmall.
+% This affects the following displayed environments:
+%    @example, @display, @format, @lisp
+%
+\def\smallword{small}
+\def\nosmallword{nosmall}
+\let\SETdispenvsize\relax
+\def\setnormaldispenv{%
+  \ifx\SETdispenvsize\smallword
+    \smallexamplefonts \rm
+  \fi
+}
+\def\setsmalldispenv{%
+  \ifx\SETdispenvsize\nosmallword
+  \else
+    \smallexamplefonts \rm
+  \fi
+}
+
+% We often define two environments, @foo and @smallfoo.
+% Let's do it by one command:
+\def\makedispenv #1#2{
+  \expandafter\envdef\csname#1\endcsname {\setnormaldispenv #2}
+  \expandafter\envdef\csname small#1\endcsname {\setsmalldispenv #2}
+  \expandafter\let\csname E#1\endcsname \afterenvbreak
+  \expandafter\let\csname Esmall#1\endcsname \afterenvbreak
+}
+
+% Define two synonyms:
+\def\maketwodispenvs #1#2#3{
+  \makedispenv{#1}{#3}
+  \makedispenv{#2}{#3}
+}
+
+% @lisp: indented, narrowed, typewriter font; @example: same as @lisp.
+%
+% @smallexample and @smalllisp: use smaller fonts.
+% Originally contributed by Pavel@xerox.
+%
+\maketwodispenvs {lisp}{example}{%
+  \nonfillstart
+  \tt\quoteexpand
+  \let\kbdfont = \kbdexamplefont % Allow @kbd to do something special.
+  \gobble       % eat return
+}
+% @display/@smalldisplay: same as @lisp except keep current font.
+%
+\makedispenv {display}{%
+  \nonfillstart
+  \gobble
+}
+
+% @format/@smallformat: same as @display except don't narrow margins.
+%
+\makedispenv{format}{%
+  \let\nonarrowing = t%
+  \nonfillstart
+  \gobble
+}
+
+% @flushleft: same as @format, but doesn't obey \SETdispenvsize.
+\envdef\flushleft{%
+  \let\nonarrowing = t%
+  \nonfillstart
+  \gobble
+}
+\let\Eflushleft = \afterenvbreak
+
+% @flushright.
+%
+\envdef\flushright{%
+  \let\nonarrowing = t%
+  \nonfillstart
+  \advance\leftskip by 0pt plus 1fill
+  \gobble
+}
+\let\Eflushright = \afterenvbreak
+
+
+% @quotation does normal linebreaking (hence we can't use \nonfillstart)
+% and narrows the margins.  We keep \parskip nonzero in general, since
+% we're doing normal filling.  So, when using \aboveenvbreak and
+% \afterenvbreak, temporarily make \parskip 0.
+%
+\envdef\quotation{%
+  {\parskip=0pt \aboveenvbreak}% because \aboveenvbreak inserts \parskip
+  \parindent=0pt
+  %
+  % @cartouche defines \nonarrowing to inhibit narrowing at next level down.
+  \ifx\nonarrowing\relax
+    \advance\leftskip by \lispnarrowing
+    \advance\rightskip by \lispnarrowing
+    \exdentamount = \lispnarrowing
+  \else
+    \let\nonarrowing = \relax
+  \fi
+  \parsearg\quotationlabel
+}
+
+% We have retained a nonzero parskip for the environment, since we're
+% doing normal filling.
+%
+\def\Equotation{%
+  \par
+  \ifx\quotationauthor\undefined\else
+    % indent a bit.
+    \leftline{\kern 2\leftskip \sl ---\quotationauthor}%
+  \fi
+  {\parskip=0pt \afterenvbreak}%
+}
+
+% If we're given an argument, typeset it in bold with a colon after.
+\def\quotationlabel#1{%
+  \def\temp{#1}%
+  \ifx\temp\empty \else
+    {\bf #1: }%
+  \fi
+}
+
+
+% LaTeX-like @verbatim...@end verbatim and @verb{<char>...<char>}
+% If we want to allow any <char> as delimiter,
+% we need the curly braces so that makeinfo sees the @verb command, eg:
+% `@verbx...x' would look like the '@verbx' command.  --janneke@gnu.org
+%
+% [Knuth]: Donald Ervin Knuth, 1996.  The TeXbook.
+%
+% [Knuth] p.344; only we need to do the other characters Texinfo sets
+% active too.  Otherwise, they get lost as the first character on a
+% verbatim line.
+\def\dospecials{%
+  \do\ \do\\\do\{\do\}\do\$\do\&%
+  \do\#\do\^\do\^^K\do\_\do\^^A\do\%\do\~%
+  \do\<\do\>\do\|\do\@\do+\do\"%
+}
+%
+% [Knuth] p. 380
+\def\uncatcodespecials{%
+  \def\do##1{\catcode`##1=\other}\dospecials}
+%
+% [Knuth] pp. 380,381,391
+% Disable Spanish ligatures ?` and !` of \tt font
+\begingroup
+  \catcode`\`=\active\gdef`{\relax\lq}
+\endgroup
+%
+% Setup for the @verb command.
+%
+% Eight spaces for a tab
+\begingroup
+  \catcode`\^^I=\active
+  \gdef\tabeightspaces{\catcode`\^^I=\active\def^^I{\ \ \ \ \ \ \ \ }}
+\endgroup
+%
+\def\setupverb{%
+  \tt  % easiest (and conventionally used) font for verbatim
+  \def\par{\leavevmode\endgraf}%
+  \catcode`\`=\active
+  \tabeightspaces
+  % Respect line breaks,
+  % print special symbols as themselves, and
+  % make each space count
+  % must do in this order:
+  \obeylines \uncatcodespecials \sepspaces
+}
+
+% Setup for the @verbatim environment
+%
+% Real tab expansion
+\newdimen\tabw \setbox0=\hbox{\tt\space} \tabw=8\wd0 % tab amount
+%
+\def\starttabbox{\setbox0=\hbox\bgroup}
+
+% Allow an option to not replace quotes with a regular directed right
+% quote/apostrophe (char 0x27), but instead use the undirected quote
+% from cmtt (char 0x0d).  The undirected quote is ugly, so don't make it
+% the default, but it works for pasting with more pdf viewers (at least
+% evince), the lilypond developers report.  xpdf does work with the
+% regular 0x27.  
+% 
+\def\codequoteright{%
+  \expandafter\ifx\csname SETcodequoteundirected\endcsname\relax
+    '%
+  \else
+    \char'15
+  \fi
+}
+%
+% and a similar option for the left quote char vs. a grave accent.
+% Modern fonts display ASCII 0x60 as a grave accent, so some people like
+% the code environments to do likewise.
+% 
+\def\codequoteleft{%
+  \expandafter\ifx\csname SETcodequotebacktick\endcsname\relax
+    `%
+  \else
+    \char'22
+  \fi
+}
+%
+\begingroup
+  \catcode`\^^I=\active
+  \gdef\tabexpand{%
+    \catcode`\^^I=\active
+    \def^^I{\leavevmode\egroup
+      \dimen0=\wd0 % the width so far, or since the previous tab
+      \divide\dimen0 by\tabw
+      \multiply\dimen0 by\tabw % compute previous multiple of \tabw
+      \advance\dimen0 by\tabw  % advance to next multiple of \tabw
+      \wd0=\dimen0 \box0 \starttabbox
+    }%
+  }
+  \catcode`\'=\active
+  \gdef\rquoteexpand{\catcode\rquoteChar=\active \def'{\codequoteright}}%
+  %
+  \catcode`\`=\active
+  \gdef\lquoteexpand{\catcode\lquoteChar=\active \def`{\codequoteleft}}%
+  %
+  \gdef\quoteexpand{\rquoteexpand \lquoteexpand}%
+\endgroup
+
+% start the verbatim environment.
+\def\setupverbatim{%
+  \let\nonarrowing = t%
+  \nonfillstart
+  % Easiest (and conventionally used) font for verbatim
+  \tt
+  \def\par{\leavevmode\egroup\box0\endgraf}%
+  \catcode`\`=\active
+  \tabexpand
+  \quoteexpand
+  % Respect line breaks,
+  % print special symbols as themselves, and
+  % make each space count
+  % must do in this order:
+  \obeylines \uncatcodespecials \sepspaces
+  \everypar{\starttabbox}%
+}
+
+% Do the @verb magic: verbatim text is quoted by unique
+% delimiter characters.  Before first delimiter expect a
+% right brace, after last delimiter expect closing brace:
+%
+%    \def\doverb'{'<char>#1<char>'}'{#1}
+%
+% [Knuth] p. 382; only eat outer {}
+\begingroup
+  \catcode`[=1\catcode`]=2\catcode`\{=\other\catcode`\}=\other
+  \gdef\doverb{#1[\def\next##1#1}[##1\endgroup]\next]
+\endgroup
+%
+\def\verb{\begingroup\setupverb\doverb}
+%
+%
+% Do the @verbatim magic: define the macro \doverbatim so that
+% the (first) argument ends when '@end verbatim' is reached, ie:
+%
+%     \def\doverbatim#1@end verbatim{#1}
+%
+% For Texinfo it's a lot easier than for LaTeX,
+% because texinfo's \verbatim doesn't stop at '\end{verbatim}':
+% we need not redefine '\', '{' and '}'.
+%
+% Inspired by LaTeX's verbatim command set [latex.ltx]
+%
+\begingroup
+  \catcode`\ =\active
+  \obeylines %
+  % ignore everything up to the first ^^M, that's the newline at the end
+  % of the @verbatim input line itself.  Otherwise we get an extra blank
+  % line in the output.
+  \xdef\doverbatim#1^^M#2@end verbatim{#2\noexpand\end\gobble verbatim}%
+  % We really want {...\end verbatim} in the body of the macro, but
+  % without the active space; thus we have to use \xdef and \gobble.
+\endgroup
+%
+\envdef\verbatim{%
+    \setupverbatim\doverbatim
+}
+\let\Everbatim = \afterenvbreak
+
+
+% @verbatiminclude FILE - insert text of file in verbatim environment.
+%
+\def\verbatiminclude{\parseargusing\filenamecatcodes\doverbatiminclude}
+%
+\def\doverbatiminclude#1{%
+  {%
+    \makevalueexpandable
+    \setupverbatim
+    \input #1
+    \afterenvbreak
+  }%
+}
+
+% @copying ... @end copying.
+% Save the text away for @insertcopying later.
+%
+% We save the uninterpreted tokens, rather than creating a box.
+% Saving the text in a box would be much easier, but then all the
+% typesetting commands (@smallbook, font changes, etc.) have to be done
+% beforehand -- and a) we want @copying to be done first in the source
+% file; b) letting users define the frontmatter in as flexible order as
+% possible is very desirable.
+%
+\def\copying{\checkenv{}\begingroup\scanargctxt\docopying}
+\def\docopying#1@end copying{\endgroup\def\copyingtext{#1}}
+%
+\def\insertcopying{%
+  \begingroup
+    \parindent = 0pt  % paragraph indentation looks wrong on title page
+    \scanexp\copyingtext
+  \endgroup
+}
+
+\message{defuns,}
+% @defun etc.
+
+\newskip\defbodyindent \defbodyindent=.4in
+\newskip\defargsindent \defargsindent=50pt
+\newskip\deflastargmargin \deflastargmargin=18pt
+
+% Start the processing of @deffn:
+\def\startdefun{%
+  \ifnum\lastpenalty<10000
+    \medbreak
+  \else
+    % If there are two @def commands in a row, we'll have a \nobreak,
+    % which is there to keep the function description together with its
+    % header.  But if there's nothing but headers, we need to allow a
+    % break somewhere.  Check specifically for penalty 10002, inserted
+    % by \defargscommonending, instead of 10000, since the sectioning
+    % commands also insert a nobreak penalty, and we don't want to allow
+    % a break between a section heading and a defun.
+    % 
+    \ifnum\lastpenalty=10002 \penalty2000 \fi
+    %
+    % Similarly, after a section heading, do not allow a break.
+    % But do insert the glue.
+    \medskip  % preceded by discardable penalty, so not a breakpoint
+  \fi
+  %
+  \parindent=0in
+  \advance\leftskip by \defbodyindent
+  \exdentamount=\defbodyindent
+}
+
+\def\dodefunx#1{%
+  % First, check whether we are in the right environment:
+  \checkenv#1%
+  %
+  % As above, allow line break if we have multiple x headers in a row.
+  % It's not a great place, though.
+  \ifnum\lastpenalty=10002 \penalty3000 \fi
+  %
+  % And now, it's time to reuse the body of the original defun:
+  \expandafter\gobbledefun#1%
+}
+\def\gobbledefun#1\startdefun{}
+
+% \printdefunline \deffnheader{text}
+%
+\def\printdefunline#1#2{%
+  \begingroup
+    % call \deffnheader:
+    #1#2 \endheader
+    % common ending:
+    \interlinepenalty = 10000
+    \advance\rightskip by 0pt plus 1fil
+    \endgraf
+    \nobreak\vskip -\parskip
+    \penalty 10002  % signal to \startdefun and \dodefunx
+    % Some of the @defun-type tags do not enable magic parentheses,
+    % rendering the following check redundant.  But we don't optimize.
+    \checkparencounts
+  \endgroup
+}
+
+\def\Edefun{\endgraf\medbreak}
+
+% \makedefun{deffn} creates \deffn, \deffnx and \Edeffn;
+% the only thing remainnig is to define \deffnheader.
+%
+\def\makedefun#1{%
+  \expandafter\let\csname E#1\endcsname = \Edefun
+  \edef\temp{\noexpand\domakedefun
+    \makecsname{#1}\makecsname{#1x}\makecsname{#1header}}%
+  \temp
+}
+
+% \domakedefun \deffn \deffnx \deffnheader
+%
+% Define \deffn and \deffnx, without parameters.
+% \deffnheader has to be defined explicitly.
+%
+\def\domakedefun#1#2#3{%
+  \envdef#1{%
+    \startdefun
+    \parseargusing\activeparens{\printdefunline#3}%
+  }%
+  \def#2{\dodefunx#1}%
+  \def#3%
+}
+
+%%% Untyped functions:
+
+% @deffn category name args
+\makedefun{deffn}{\deffngeneral{}}
+
+% @deffn category class name args
+\makedefun{defop}#1 {\defopon{#1\ \putwordon}}
+
+% \defopon {category on}class name args
+\def\defopon#1#2 {\deffngeneral{\putwordon\ \code{#2}}{#1\ \code{#2}} }
+
+% \deffngeneral {subind}category name args
+%
+\def\deffngeneral#1#2 #3 #4\endheader{%
+  % Remember that \dosubind{fn}{foo}{} is equivalent to \doind{fn}{foo}.
+  \dosubind{fn}{\code{#3}}{#1}%
+  \defname{#2}{}{#3}\magicamp\defunargs{#4\unskip}%
+}
+
+%%% Typed functions:
+
+% @deftypefn category type name args
+\makedefun{deftypefn}{\deftypefngeneral{}}
+
+% @deftypeop category class type name args
+\makedefun{deftypeop}#1 {\deftypeopon{#1\ \putwordon}}
+
+% \deftypeopon {category on}class type name args
+\def\deftypeopon#1#2 {\deftypefngeneral{\putwordon\ \code{#2}}{#1\ \code{#2}} }
+
+% \deftypefngeneral {subind}category type name args
+%
+\def\deftypefngeneral#1#2 #3 #4 #5\endheader{%
+  \dosubind{fn}{\code{#4}}{#1}%
+  \defname{#2}{#3}{#4}\defunargs{#5\unskip}%
+}
+
+%%% Typed variables:
+
+% @deftypevr category type var args
+\makedefun{deftypevr}{\deftypecvgeneral{}}
+
+% @deftypecv category class type var args
+\makedefun{deftypecv}#1 {\deftypecvof{#1\ \putwordof}}
+
+% \deftypecvof {category of}class type var args
+\def\deftypecvof#1#2 {\deftypecvgeneral{\putwordof\ \code{#2}}{#1\ \code{#2}} }
+
+% \deftypecvgeneral {subind}category type var args
+%
+\def\deftypecvgeneral#1#2 #3 #4 #5\endheader{%
+  \dosubind{vr}{\code{#4}}{#1}%
+  \defname{#2}{#3}{#4}\defunargs{#5\unskip}%
+}
+
+%%% Untyped variables:
+
+% @defvr category var args
+\makedefun{defvr}#1 {\deftypevrheader{#1} {} }
+
+% @defcv category class var args
+\makedefun{defcv}#1 {\defcvof{#1\ \putwordof}}
+
+% \defcvof {category of}class var args
+\def\defcvof#1#2 {\deftypecvof{#1}#2 {} }
+
+%%% Type:
+% @deftp category name args
+\makedefun{deftp}#1 #2 #3\endheader{%
+  \doind{tp}{\code{#2}}%
+  \defname{#1}{}{#2}\defunargs{#3\unskip}%
+}
+
+% Remaining @defun-like shortcuts:
+\makedefun{defun}{\deffnheader{\putwordDeffunc} }
+\makedefun{defmac}{\deffnheader{\putwordDefmac} }
+\makedefun{defspec}{\deffnheader{\putwordDefspec} }
+\makedefun{deftypefun}{\deftypefnheader{\putwordDeffunc} }
+\makedefun{defvar}{\defvrheader{\putwordDefvar} }
+\makedefun{defopt}{\defvrheader{\putwordDefopt} }
+\makedefun{deftypevar}{\deftypevrheader{\putwordDefvar} }
+\makedefun{defmethod}{\defopon\putwordMethodon}
+\makedefun{deftypemethod}{\deftypeopon\putwordMethodon}
+\makedefun{defivar}{\defcvof\putwordInstanceVariableof}
+\makedefun{deftypeivar}{\deftypecvof\putwordInstanceVariableof}
+
+% \defname, which formats the name of the @def (not the args).
+% #1 is the category, such as "Function".
+% #2 is the return type, if any.
+% #3 is the function name.
+%
+% We are followed by (but not passed) the arguments, if any.
+%
+\def\defname#1#2#3{%
+  % Get the values of \leftskip and \rightskip as they were outside the @def...
+  \advance\leftskip by -\defbodyindent
+  %
+  % How we'll format the type name.  Putting it in brackets helps
+  % distinguish it from the body text that may end up on the next line
+  % just below it.
+  \def\temp{#1}%
+  \setbox0=\hbox{\kern\deflastargmargin \ifx\temp\empty\else [\rm\temp]\fi}
+  %
+  % Figure out line sizes for the paragraph shape.
+  % The first line needs space for \box0; but if \rightskip is nonzero,
+  % we need only space for the part of \box0 which exceeds it:
+  \dimen0=\hsize  \advance\dimen0 by -\wd0  \advance\dimen0 by \rightskip
+  % The continuations:
+  \dimen2=\hsize  \advance\dimen2 by -\defargsindent
+  % (plain.tex says that \dimen1 should be used only as global.)
+  \parshape 2 0in \dimen0 \defargsindent \dimen2
+  %
+  % Put the type name to the right margin.
+  \noindent
+  \hbox to 0pt{%
+    \hfil\box0 \kern-\hsize
+    % \hsize has to be shortened this way:
+    \kern\leftskip
+    % Intentionally do not respect \rightskip, since we need the space.
+  }%
+  %
+  % Allow all lines to be underfull without complaint:
+  \tolerance=10000 \hbadness=10000
+  \exdentamount=\defbodyindent
+  {%
+    % defun fonts. We use typewriter by default (used to be bold) because:
+    % . we're printing identifiers, they should be in tt in principle.
+    % . in languages with many accents, such as Czech or French, it's
+    %   common to leave accents off identifiers.  The result looks ok in
+    %   tt, but exceedingly strange in rm.
+    % . we don't want -- and --- to be treated as ligatures.
+    % . this still does not fix the ?` and !` ligatures, but so far no
+    %   one has made identifiers using them :).
+    \df \tt
+    \def\temp{#2}% return value type
+    \ifx\temp\empty\else \tclose{\temp} \fi
+    #3% output function name
+  }%
+  {\rm\enskip}% hskip 0.5 em of \tenrm
+  %
+  \boldbrax
+  % arguments will be output next, if any.
+}
+
+% Print arguments in slanted roman (not ttsl), inconsistently with using
+% tt for the name.  This is because literal text is sometimes needed in
+% the argument list (groff manual), and ttsl and tt are not very
+% distinguishable.  Prevent hyphenation at `-' chars.
+%
+\def\defunargs#1{%
+  % use sl by default (not ttsl),
+  % tt for the names.
+  \df \sl \hyphenchar\font=0
+  %
+  % On the other hand, if an argument has two dashes (for instance), we
+  % want a way to get ttsl.  Let's try @var for that.
+  \let\var=\ttslanted
+  #1%
+  \sl\hyphenchar\font=45
+}
+
+% We want ()&[] to print specially on the defun line.
+%
+\def\activeparens{%
+  \catcode`\(=\active \catcode`\)=\active
+  \catcode`\[=\active \catcode`\]=\active
+  \catcode`\&=\active
+}
+
+% Make control sequences which act like normal parenthesis chars.
+\let\lparen = ( \let\rparen = )
+
+% Be sure that we always have a definition for `(', etc.  For example,
+% if the fn name has parens in it, \boldbrax will not be in effect yet,
+% so TeX would otherwise complain about undefined control sequence.
+{
+  \activeparens
+  \global\let(=\lparen \global\let)=\rparen
+  \global\let[=\lbrack \global\let]=\rbrack
+  \global\let& = \&
+
+  \gdef\boldbrax{\let(=\opnr\let)=\clnr\let[=\lbrb\let]=\rbrb}
+  \gdef\magicamp{\let&=\amprm}
+}
+
+\newcount\parencount
+
+% If we encounter &foo, then turn on ()-hacking afterwards
+\newif\ifampseen
+\def\amprm#1 {\ampseentrue{\bf\&#1 }}
+
+\def\parenfont{%
+  \ifampseen
+    % At the first level, print parens in roman,
+    % otherwise use the default font.
+    \ifnum \parencount=1 \rm \fi
+  \else
+    % The \sf parens (in \boldbrax) actually are a little bolder than
+    % the contained text.  This is especially needed for [ and ] .
+    \sf
+  \fi
+}
+\def\infirstlevel#1{%
+  \ifampseen
+    \ifnum\parencount=1
+      #1%
+    \fi
+  \fi
+}
+\def\bfafterword#1 {#1 \bf}
+
+\def\opnr{%
+  \global\advance\parencount by 1
+  {\parenfont(}%
+  \infirstlevel \bfafterword
+}
+\def\clnr{%
+  {\parenfont)}%
+  \infirstlevel \sl
+  \global\advance\parencount by -1
+}
+
+\newcount\brackcount
+\def\lbrb{%
+  \global\advance\brackcount by 1
+  {\bf[}%
+}
+\def\rbrb{%
+  {\bf]}%
+  \global\advance\brackcount by -1
+}
+
+\def\checkparencounts{%
+  \ifnum\parencount=0 \else \badparencount \fi
+  \ifnum\brackcount=0 \else \badbrackcount \fi
+}
+\def\badparencount{%
+  \errmessage{Unbalanced parentheses in @def}%
+  \global\parencount=0
+}
+\def\badbrackcount{%
+  \errmessage{Unbalanced square braces in @def}%
+  \global\brackcount=0
+}
+
+
+\message{macros,}
+% @macro.
+
+% To do this right we need a feature of e-TeX, \scantokens,
+% which we arrange to emulate with a temporary file in ordinary TeX.
+\ifx\eTeXversion\undefined
+  \newwrite\macscribble
+  \def\scantokens#1{%
+    \toks0={#1}%
+    \immediate\openout\macscribble=\jobname.tmp
+    \immediate\write\macscribble{\the\toks0}%
+    \immediate\closeout\macscribble
+    \input \jobname.tmp
+  }
+\fi
+
+\def\scanmacro#1{%
+  \begingroup
+    \newlinechar`\^^M
+    \let\xeatspaces\eatspaces
+    % Undo catcode changes of \startcontents and \doprintindex
+    % When called from @insertcopying or (short)caption, we need active
+    % backslash to get it printed correctly.  Previously, we had
+    % \catcode`\\=\other instead.  We'll see whether a problem appears
+    % with macro expansion.				--kasal, 19aug04
+    \catcode`\@=0 \catcode`\\=\active \escapechar=`\@
+    % ... and \example
+    \spaceisspace
+    %
+    % Append \endinput to make sure that TeX does not see the ending newline.
+    % I've verified that it is necessary both for e-TeX and for ordinary TeX
+    %							--kasal, 29nov03
+    \scantokens{#1\endinput}%
+  \endgroup
+}
+
+\def\scanexp#1{%
+  \edef\temp{\noexpand\scanmacro{#1}}%
+  \temp
+}
+
+\newcount\paramno   % Count of parameters
+\newtoks\macname    % Macro name
+\newif\ifrecursive  % Is it recursive?
+
+% List of all defined macros in the form
+%    \definedummyword\macro1\definedummyword\macro2...
+% Currently is also contains all @aliases; the list can be split
+% if there is a need.
+\def\macrolist{}
+
+% Add the macro to \macrolist
+\def\addtomacrolist#1{\expandafter \addtomacrolistxxx \csname#1\endcsname}
+\def\addtomacrolistxxx#1{%
+     \toks0 = \expandafter{\macrolist\definedummyword#1}%
+     \xdef\macrolist{\the\toks0}%
+}
+
+% Utility routines.
+% This does \let #1 = #2, with \csnames; that is,
+%   \let \csname#1\endcsname = \csname#2\endcsname
+% (except of course we have to play expansion games).
+% 
+\def\cslet#1#2{%
+  \expandafter\let
+  \csname#1\expandafter\endcsname
+  \csname#2\endcsname
+}
+
+% Trim leading and trailing spaces off a string.
+% Concepts from aro-bend problem 15 (see CTAN).
+{\catcode`\@=11
+\gdef\eatspaces #1{\expandafter\trim@\expandafter{#1 }}
+\gdef\trim@ #1{\trim@@ @#1 @ #1 @ @@}
+\gdef\trim@@ #1@ #2@ #3@@{\trim@@@\empty #2 @}
+\def\unbrace#1{#1}
+\unbrace{\gdef\trim@@@ #1 } #2@{#1}
+}
+
+% Trim a single trailing ^^M off a string.
+{\catcode`\^^M=\other \catcode`\Q=3%
+\gdef\eatcr #1{\eatcra #1Q^^MQ}%
+\gdef\eatcra#1^^MQ{\eatcrb#1Q}%
+\gdef\eatcrb#1Q#2Q{#1}%
+}
+
+% Macro bodies are absorbed as an argument in a context where
+% all characters are catcode 10, 11 or 12, except \ which is active
+% (as in normal texinfo). It is necessary to change the definition of \.
+
+% It's necessary to have hard CRs when the macro is executed. This is
+% done by  making ^^M (\endlinechar) catcode 12 when reading the macro
+% body, and then making it the \newlinechar in \scanmacro.
+
+\def\scanctxt{%
+  \catcode`\"=\other
+  \catcode`\+=\other
+  \catcode`\<=\other
+  \catcode`\>=\other
+  \catcode`\@=\other
+  \catcode`\^=\other
+  \catcode`\_=\other
+  \catcode`\|=\other
+  \catcode`\~=\other
+}
+
+\def\scanargctxt{%
+  \scanctxt
+  \catcode`\\=\other
+  \catcode`\^^M=\other
+}
+
+\def\macrobodyctxt{%
+  \scanctxt
+  \catcode`\{=\other
+  \catcode`\}=\other
+  \catcode`\^^M=\other
+  \usembodybackslash
+}
+
+\def\macroargctxt{%
+  \scanctxt
+  \catcode`\\=\other
+}
+
+% \mbodybackslash is the definition of \ in @macro bodies.
+% It maps \foo\ => \csname macarg.foo\endcsname => #N
+% where N is the macro parameter number.
+% We define \csname macarg.\endcsname to be \realbackslash, so
+% \\ in macro replacement text gets you a backslash.
+
+{\catcode`@=0 @catcode`@\=@active
+ @gdef@usembodybackslash{@let\=@mbodybackslash}
+ @gdef@mbodybackslash#1\{@csname macarg.#1@endcsname}
+}
+\expandafter\def\csname macarg.\endcsname{\realbackslash}
+
+\def\macro{\recursivefalse\parsearg\macroxxx}
+\def\rmacro{\recursivetrue\parsearg\macroxxx}
+
+\def\macroxxx#1{%
+  \getargs{#1}%           now \macname is the macname and \argl the arglist
+  \ifx\argl\empty       % no arguments
+     \paramno=0%
+  \else
+     \expandafter\parsemargdef \argl;%
+  \fi
+  \if1\csname ismacro.\the\macname\endcsname
+     \message{Warning: redefining \the\macname}%
+  \else
+     \expandafter\ifx\csname \the\macname\endcsname \relax
+     \else \errmessage{Macro name \the\macname\space already defined}\fi
+     \global\cslet{macsave.\the\macname}{\the\macname}%
+     \global\expandafter\let\csname ismacro.\the\macname\endcsname=1%
+     \addtomacrolist{\the\macname}%
+  \fi
+  \begingroup \macrobodyctxt
+  \ifrecursive \expandafter\parsermacbody
+  \else \expandafter\parsemacbody
+  \fi}
+
+\parseargdef\unmacro{%
+  \if1\csname ismacro.#1\endcsname
+    \global\cslet{#1}{macsave.#1}%
+    \global\expandafter\let \csname ismacro.#1\endcsname=0%
+    % Remove the macro name from \macrolist:
+    \begingroup
+      \expandafter\let\csname#1\endcsname \relax
+      \let\definedummyword\unmacrodo
+      \xdef\macrolist{\macrolist}%
+    \endgroup
+  \else
+    \errmessage{Macro #1 not defined}%
+  \fi
+}
+
+% Called by \do from \dounmacro on each macro.  The idea is to omit any
+% macro definitions that have been changed to \relax.
+%
+\def\unmacrodo#1{%
+  \ifx #1\relax
+    % remove this
+  \else
+    \noexpand\definedummyword \noexpand#1%
+  \fi
+}
+
+% This makes use of the obscure feature that if the last token of a
+% <parameter list> is #, then the preceding argument is delimited by
+% an opening brace, and that opening brace is not consumed.
+\def\getargs#1{\getargsxxx#1{}}
+\def\getargsxxx#1#{\getmacname #1 \relax\getmacargs}
+\def\getmacname #1 #2\relax{\macname={#1}}
+\def\getmacargs#1{\def\argl{#1}}
+
+% Parse the optional {params} list.  Set up \paramno and \paramlist
+% so \defmacro knows what to do.  Define \macarg.blah for each blah
+% in the params list, to be ##N where N is the position in that list.
+% That gets used by \mbodybackslash (above).
+
+% We need to get `macro parameter char #' into several definitions.
+% The technique used is stolen from LaTeX:  let \hash be something
+% unexpandable, insert that wherever you need a #, and then redefine
+% it to # just before using the token list produced.
+%
+% The same technique is used to protect \eatspaces till just before
+% the macro is used.
+
+\def\parsemargdef#1;{\paramno=0\def\paramlist{}%
+        \let\hash\relax\let\xeatspaces\relax\parsemargdefxxx#1,;,}
+\def\parsemargdefxxx#1,{%
+  \if#1;\let\next=\relax
+  \else \let\next=\parsemargdefxxx
+    \advance\paramno by 1%
+    \expandafter\edef\csname macarg.\eatspaces{#1}\endcsname
+        {\xeatspaces{\hash\the\paramno}}%
+    \edef\paramlist{\paramlist\hash\the\paramno,}%
+  \fi\next}
+
+% These two commands read recursive and nonrecursive macro bodies.
+% (They're different since rec and nonrec macros end differently.)
+
+\long\def\parsemacbody#1@end macro%
+{\xdef\temp{\eatcr{#1}}\endgroup\defmacro}%
+\long\def\parsermacbody#1@end rmacro%
+{\xdef\temp{\eatcr{#1}}\endgroup\defmacro}%
+
+% This defines the macro itself. There are six cases: recursive and
+% nonrecursive macros of zero, one, and many arguments.
+% Much magic with \expandafter here.
+% \xdef is used so that macro definitions will survive the file
+% they're defined in; @include reads the file inside a group.
+\def\defmacro{%
+  \let\hash=##% convert placeholders to macro parameter chars
+  \ifrecursive
+    \ifcase\paramno
+    % 0
+      \expandafter\xdef\csname\the\macname\endcsname{%
+        \noexpand\scanmacro{\temp}}%
+    \or % 1
+      \expandafter\xdef\csname\the\macname\endcsname{%
+         \bgroup\noexpand\macroargctxt
+         \noexpand\braceorline
+         \expandafter\noexpand\csname\the\macname xxx\endcsname}%
+      \expandafter\xdef\csname\the\macname xxx\endcsname##1{%
+         \egroup\noexpand\scanmacro{\temp}}%
+    \else % many
+      \expandafter\xdef\csname\the\macname\endcsname{%
+         \bgroup\noexpand\macroargctxt
+         \noexpand\csname\the\macname xx\endcsname}%
+      \expandafter\xdef\csname\the\macname xx\endcsname##1{%
+          \expandafter\noexpand\csname\the\macname xxx\endcsname ##1,}%
+      \expandafter\expandafter
+      \expandafter\xdef
+      \expandafter\expandafter
+        \csname\the\macname xxx\endcsname
+          \paramlist{\egroup\noexpand\scanmacro{\temp}}%
+    \fi
+  \else
+    \ifcase\paramno
+    % 0
+      \expandafter\xdef\csname\the\macname\endcsname{%
+        \noexpand\norecurse{\the\macname}%
+        \noexpand\scanmacro{\temp}\egroup}%
+    \or % 1
+      \expandafter\xdef\csname\the\macname\endcsname{%
+         \bgroup\noexpand\macroargctxt
+         \noexpand\braceorline
+         \expandafter\noexpand\csname\the\macname xxx\endcsname}%
+      \expandafter\xdef\csname\the\macname xxx\endcsname##1{%
+        \egroup
+        \noexpand\norecurse{\the\macname}%
+        \noexpand\scanmacro{\temp}\egroup}%
+    \else % many
+      \expandafter\xdef\csname\the\macname\endcsname{%
+         \bgroup\noexpand\macroargctxt
+         \expandafter\noexpand\csname\the\macname xx\endcsname}%
+      \expandafter\xdef\csname\the\macname xx\endcsname##1{%
+          \expandafter\noexpand\csname\the\macname xxx\endcsname ##1,}%
+      \expandafter\expandafter
+      \expandafter\xdef
+      \expandafter\expandafter
+      \csname\the\macname xxx\endcsname
+      \paramlist{%
+          \egroup
+          \noexpand\norecurse{\the\macname}%
+          \noexpand\scanmacro{\temp}\egroup}%
+    \fi
+  \fi}
+
+\def\norecurse#1{\bgroup\cslet{#1}{macsave.#1}}
+
+% \braceorline decides whether the next nonwhitespace character is a
+% {.  If so it reads up to the closing }, if not, it reads the whole
+% line.  Whatever was read is then fed to the next control sequence
+% as an argument (by \parsebrace or \parsearg)
+\def\braceorline#1{\let\macnamexxx=#1\futurelet\nchar\braceorlinexxx}
+\def\braceorlinexxx{%
+  \ifx\nchar\bgroup\else
+    \expandafter\parsearg
+  \fi \macnamexxx}
+
+
+% @alias.
+% We need some trickery to remove the optional spaces around the equal
+% sign.  Just make them active and then expand them all to nothing.
+\def\alias{\parseargusing\obeyspaces\aliasxxx}
+\def\aliasxxx #1{\aliasyyy#1\relax}
+\def\aliasyyy #1=#2\relax{%
+  {%
+    \expandafter\let\obeyedspace=\empty
+    \addtomacrolist{#1}%
+    \xdef\next{\global\let\makecsname{#1}=\makecsname{#2}}%
+  }%
+  \next
+}
+
+
+\message{cross references,}
+
+\newwrite\auxfile
+
+\newif\ifhavexrefs    % True if xref values are known.
+\newif\ifwarnedxrefs  % True if we warned once that they aren't known.
+
+% @inforef is relatively simple.
+\def\inforef #1{\inforefzzz #1,,,,**}
+\def\inforefzzz #1,#2,#3,#4**{\putwordSee{} \putwordInfo{} \putwordfile{} \file{\ignorespaces #3{}},
+  node \samp{\ignorespaces#1{}}}
+
+% @node's only job in TeX is to define \lastnode, which is used in
+% cross-references.  The @node line might or might not have commas, and
+% might or might not have spaces before the first comma, like:
+% @node foo , bar , ...
+% We don't want such trailing spaces in the node name.
+%
+\parseargdef\node{\checkenv{}\donode #1 ,\finishnodeparse}
+%
+% also remove a trailing comma, in case of something like this:
+% @node Help-Cross,  ,  , Cross-refs
+\def\donode#1 ,#2\finishnodeparse{\dodonode #1,\finishnodeparse}
+\def\dodonode#1,#2\finishnodeparse{\gdef\lastnode{#1}}
+
+\let\nwnode=\node
+\let\lastnode=\empty
+
+% Write a cross-reference definition for the current node.  #1 is the
+% type (Ynumbered, Yappendix, Ynothing).
+%
+\def\donoderef#1{%
+  \ifx\lastnode\empty\else
+    \setref{\lastnode}{#1}%
+    \global\let\lastnode=\empty
+  \fi
+}
+
+% @anchor{NAME} -- define xref target at arbitrary point.
+%
+\newcount\savesfregister
+%
+\def\savesf{\relax \ifhmode \savesfregister=\spacefactor \fi}
+\def\restoresf{\relax \ifhmode \spacefactor=\savesfregister \fi}
+\def\anchor#1{\savesf \setref{#1}{Ynothing}\restoresf \ignorespaces}
+
+% \setref{NAME}{SNT} defines a cross-reference point NAME (a node or an
+% anchor), which consists of three parts:
+% 1) NAME-title - the current sectioning name taken from \thissection,
+%                 or the anchor name.
+% 2) NAME-snt   - section number and type, passed as the SNT arg, or
+%                 empty for anchors.
+% 3) NAME-pg    - the page number.
+%
+% This is called from \donoderef, \anchor, and \dofloat.  In the case of
+% floats, there is an additional part, which is not written here:
+% 4) NAME-lof   - the text as it should appear in a @listoffloats.
+%
+\def\setref#1#2{%
+  \pdfmkdest{#1}%
+  \iflinks
+    {%
+      \atdummies  % preserve commands, but don't expand them
+      \edef\writexrdef##1##2{%
+	\write\auxfile{@xrdef{#1-% #1 of \setref, expanded by the \edef
+	  ##1}{##2}}% these are parameters of \writexrdef
+      }%
+      \toks0 = \expandafter{\thissection}%
+      \immediate \writexrdef{title}{\the\toks0 }%
+      \immediate \writexrdef{snt}{\csname #2\endcsname}% \Ynumbered etc.
+      \writexrdef{pg}{\folio}% will be written later, during \shipout
+    }%
+  \fi
+}
+
+% @xref, @pxref, and @ref generate cross-references.  For \xrefX, #1 is
+% the node name, #2 the name of the Info cross-reference, #3 the printed
+% node name, #4 the name of the Info file, #5 the name of the printed
+% manual.  All but the node name can be omitted.
+%
+\def\pxref#1{\putwordsee{} \xrefX[#1,,,,,,,]}
+\def\xref#1{\putwordSee{} \xrefX[#1,,,,,,,]}
+\def\ref#1{\xrefX[#1,,,,,,,]}
+\def\xrefX[#1,#2,#3,#4,#5,#6]{\begingroup
+  \unsepspaces
+  \def\printedmanual{\ignorespaces #5}%
+  \def\printedrefname{\ignorespaces #3}%
+  \setbox1=\hbox{\printedmanual\unskip}%
+  \setbox0=\hbox{\printedrefname\unskip}%
+  \ifdim \wd0 = 0pt
+    % No printed node name was explicitly given.
+    \expandafter\ifx\csname SETxref-automatic-section-title\endcsname\relax
+      % Use the node name inside the square brackets.
+      \def\printedrefname{\ignorespaces #1}%
+    \else
+      % Use the actual chapter/section title appear inside
+      % the square brackets.  Use the real section title if we have it.
+      \ifdim \wd1 > 0pt
+        % It is in another manual, so we don't have it.
+        \def\printedrefname{\ignorespaces #1}%
+      \else
+        \ifhavexrefs
+          % We know the real title if we have the xref values.
+          \def\printedrefname{\refx{#1-title}{}}%
+        \else
+          % Otherwise just copy the Info node name.
+          \def\printedrefname{\ignorespaces #1}%
+        \fi%
+      \fi
+    \fi
+  \fi
+  %
+  % Make link in pdf output.
+  \ifpdf
+    \leavevmode
+    \getfilename{#4}%
+    {\turnoffactive
+     % See comments at \activebackslashdouble.
+     {\activebackslashdouble \xdef\pdfxrefdest{#1}%
+      \backslashparens\pdfxrefdest}%
+     %
+     \ifnum\filenamelength>0
+       \startlink attr{/Border [0 0 0]}%
+         goto file{\the\filename.pdf} name{\pdfxrefdest}%
+     \else
+       \startlink attr{/Border [0 0 0]}%
+         goto name{\pdfmkpgn{\pdfxrefdest}}%
+     \fi
+    }%
+    \linkcolor
+  \fi
+  %
+  % Float references are printed completely differently: "Figure 1.2"
+  % instead of "[somenode], p.3".  We distinguish them by the
+  % LABEL-title being set to a magic string.
+  {%
+    % Have to otherify everything special to allow the \csname to
+    % include an _ in the xref name, etc.
+    \indexnofonts
+    \turnoffactive
+    \expandafter\global\expandafter\let\expandafter\Xthisreftitle
+      \csname XR#1-title\endcsname
+  }%
+  \iffloat\Xthisreftitle
+    % If the user specified the print name (third arg) to the ref,
+    % print it instead of our usual "Figure 1.2".
+    \ifdim\wd0 = 0pt
+      \refx{#1-snt}{}%
+    \else
+      \printedrefname
+    \fi
+    %
+    % if the user also gave the printed manual name (fifth arg), append
+    % "in MANUALNAME".
+    \ifdim \wd1 > 0pt
+      \space \putwordin{} \cite{\printedmanual}%
+    \fi
+  \else
+    % node/anchor (non-float) references.
+    %
+    % If we use \unhbox0 and \unhbox1 to print the node names, TeX does not
+    % insert empty discretionaries after hyphens, which means that it will
+    % not find a line break at a hyphen in a node names.  Since some manuals
+    % are best written with fairly long node names, containing hyphens, this
+    % is a loss.  Therefore, we give the text of the node name again, so it
+    % is as if TeX is seeing it for the first time.
+    \ifdim \wd1 > 0pt
+      \putwordsection{} ``\printedrefname'' \putwordin{} \cite{\printedmanual}%
+    \else
+      % _ (for example) has to be the character _ for the purposes of the
+      % control sequence corresponding to the node, but it has to expand
+      % into the usual \leavevmode...\vrule stuff for purposes of
+      % printing. So we \turnoffactive for the \refx-snt, back on for the
+      % printing, back off for the \refx-pg.
+      {\turnoffactive
+       % Only output a following space if the -snt ref is nonempty; for
+       % @unnumbered and @anchor, it won't be.
+       \setbox2 = \hbox{\ignorespaces \refx{#1-snt}{}}%
+       \ifdim \wd2 > 0pt \refx{#1-snt}\space\fi
+      }%
+      % output the `[mynode]' via a macro so it can be overridden.
+      \xrefprintnodename\printedrefname
+      %
+      % But we always want a comma and a space:
+      ,\space
+      %
+      % output the `page 3'.
+      \turnoffactive \putwordpage\tie\refx{#1-pg}{}%
+    \fi
+  \fi
+  \endlink
+\endgroup}
+
+% This macro is called from \xrefX for the `[nodename]' part of xref
+% output.  It's a separate macro only so it can be changed more easily,
+% since square brackets don't work well in some documents.  Particularly
+% one that Bob is working on :).
+%
+\def\xrefprintnodename#1{[#1]}
+
+% Things referred to by \setref.
+%
+\def\Ynothing{}
+\def\Yomitfromtoc{}
+\def\Ynumbered{%
+  \ifnum\secno=0
+    \putwordChapter@tie \the\chapno
+  \else \ifnum\subsecno=0
+    \putwordSection@tie \the\chapno.\the\secno
+  \else \ifnum\subsubsecno=0
+    \putwordSection@tie \the\chapno.\the\secno.\the\subsecno
+  \else
+    \putwordSection@tie \the\chapno.\the\secno.\the\subsecno.\the\subsubsecno
+  \fi\fi\fi
+}
+\def\Yappendix{%
+  \ifnum\secno=0
+     \putwordAppendix@tie @char\the\appendixno{}%
+  \else \ifnum\subsecno=0
+     \putwordSection@tie @char\the\appendixno.\the\secno
+  \else \ifnum\subsubsecno=0
+    \putwordSection@tie @char\the\appendixno.\the\secno.\the\subsecno
+  \else
+    \putwordSection@tie
+      @char\the\appendixno.\the\secno.\the\subsecno.\the\subsubsecno
+  \fi\fi\fi
+}
+
+% Define \refx{NAME}{SUFFIX} to reference a cross-reference string named NAME.
+% If its value is nonempty, SUFFIX is output afterward.
+%
+\def\refx#1#2{%
+  {%
+    \indexnofonts
+    \otherbackslash
+    \expandafter\global\expandafter\let\expandafter\thisrefX
+      \csname XR#1\endcsname
+  }%
+  \ifx\thisrefX\relax
+    % If not defined, say something at least.
+    \angleleft un\-de\-fined\angleright
+    \iflinks
+      \ifhavexrefs
+        \message{\linenumber Undefined cross reference `#1'.}%
+      \else
+        \ifwarnedxrefs\else
+          \global\warnedxrefstrue
+          \message{Cross reference values unknown; you must run TeX again.}%
+        \fi
+      \fi
+    \fi
+  \else
+    % It's defined, so just use it.
+    \thisrefX
+  \fi
+  #2% Output the suffix in any case.
+}
+
+% This is the macro invoked by entries in the aux file.  Usually it's
+% just a \def (we prepend XR to the control sequence name to avoid
+% collisions).  But if this is a float type, we have more work to do.
+%
+\def\xrdef#1#2{%
+  \expandafter\gdef\csname XR#1\endcsname{#2}% remember this xref value.
+  %
+  % Was that xref control sequence that we just defined for a float?
+  \expandafter\iffloat\csname XR#1\endcsname
+    % it was a float, and we have the (safe) float type in \iffloattype.
+    \expandafter\let\expandafter\floatlist
+      \csname floatlist\iffloattype\endcsname
+    %
+    % Is this the first time we've seen this float type?
+    \expandafter\ifx\floatlist\relax
+      \toks0 = {\do}% yes, so just \do
+    \else
+      % had it before, so preserve previous elements in list.
+      \toks0 = \expandafter{\floatlist\do}%
+    \fi
+    %
+    % Remember this xref in the control sequence \floatlistFLOATTYPE,
+    % for later use in \listoffloats.
+    \expandafter\xdef\csname floatlist\iffloattype\endcsname{\the\toks0{#1}}%
+  \fi
+}
+
+% Read the last existing aux file, if any.  No error if none exists.
+%
+\def\tryauxfile{%
+  \openin 1 \jobname.aux
+  \ifeof 1 \else
+    \readdatafile{aux}%
+    \global\havexrefstrue
+  \fi
+  \closein 1
+}
+
+\def\setupdatafile{%
+  \catcode`\^^@=\other
+  \catcode`\^^A=\other
+  \catcode`\^^B=\other
+  \catcode`\^^C=\other
+  \catcode`\^^D=\other
+  \catcode`\^^E=\other
+  \catcode`\^^F=\other
+  \catcode`\^^G=\other
+  \catcode`\^^H=\other
+  \catcode`\^^K=\other
+  \catcode`\^^L=\other
+  \catcode`\^^N=\other
+  \catcode`\^^P=\other
+  \catcode`\^^Q=\other
+  \catcode`\^^R=\other
+  \catcode`\^^S=\other
+  \catcode`\^^T=\other
+  \catcode`\^^U=\other
+  \catcode`\^^V=\other
+  \catcode`\^^W=\other
+  \catcode`\^^X=\other
+  \catcode`\^^Z=\other
+  \catcode`\^^[=\other
+  \catcode`\^^\=\other
+  \catcode`\^^]=\other
+  \catcode`\^^^=\other
+  \catcode`\^^_=\other
+  % It was suggested to set the catcode of ^ to 7, which would allow ^^e4 etc.
+  % in xref tags, i.e., node names.  But since ^^e4 notation isn't
+  % supported in the main text, it doesn't seem desirable.  Furthermore,
+  % that is not enough: for node names that actually contain a ^
+  % character, we would end up writing a line like this: 'xrdef {'hat
+  % b-title}{'hat b} and \xrdef does a \csname...\endcsname on the first
+  % argument, and \hat is not an expandable control sequence.  It could
+  % all be worked out, but why?  Either we support ^^ or we don't.
+  %
+  % The other change necessary for this was to define \auxhat:
+  % \def\auxhat{\def^{'hat }}% extra space so ok if followed by letter
+  % and then to call \auxhat in \setq.
+  %
+  \catcode`\^=\other
+  %
+  % Special characters.  Should be turned off anyway, but...
+  \catcode`\~=\other
+  \catcode`\[=\other
+  \catcode`\]=\other
+  \catcode`\"=\other
+  \catcode`\_=\other
+  \catcode`\|=\other
+  \catcode`\<=\other
+  \catcode`\>=\other
+  \catcode`\$=\other
+  \catcode`\#=\other
+  \catcode`\&=\other
+  \catcode`\%=\other
+  \catcode`+=\other % avoid \+ for paranoia even though we've turned it off
+  %
+  % This is to support \ in node names and titles, since the \
+  % characters end up in a \csname.  It's easier than
+  % leaving it active and making its active definition an actual \
+  % character.  What I don't understand is why it works in the *value*
+  % of the xrdef.  Seems like it should be a catcode12 \, and that
+  % should not typeset properly.  But it works, so I'm moving on for
+  % now.  --karl, 15jan04.
+  \catcode`\\=\other
+  %
+  % Make the characters 128-255 be printing characters.
+  {%
+    \count1=128
+    \def\loop{%
+      \catcode\count1=\other
+      \advance\count1 by 1
+      \ifnum \count1<256 \loop \fi
+    }%
+  }%
+  %
+  % @ is our escape character in .aux files, and we need braces.
+  \catcode`\{=1
+  \catcode`\}=2
+  \catcode`\@=0
+}
+
+\def\readdatafile#1{%
+\begingroup
+  \setupdatafile
+  \input\jobname.#1
+\endgroup}
+
+\message{insertions,}
+% including footnotes.
+
+\newcount \footnoteno
+
+% The trailing space in the following definition for supereject is
+% vital for proper filling; pages come out unaligned when you do a
+% pagealignmacro call if that space before the closing brace is
+% removed. (Generally, numeric constants should always be followed by a
+% space to prevent strange expansion errors.)
+\def\supereject{\par\penalty -20000\footnoteno =0 }
+
+% @footnotestyle is meaningful for info output only.
+\let\footnotestyle=\comment
+
+{\catcode `\@=11
+%
+% Auto-number footnotes.  Otherwise like plain.
+\gdef\footnote{%
+  \let\indent=\ptexindent
+  \let\noindent=\ptexnoindent
+  \global\advance\footnoteno by \@ne
+  \edef\thisfootno{$^{\the\footnoteno}$}%
+  %
+  % In case the footnote comes at the end of a sentence, preserve the
+  % extra spacing after we do the footnote number.
+  \let\@sf\empty
+  \ifhmode\edef\@sf{\spacefactor\the\spacefactor}\ptexslash\fi
+  %
+  % Remove inadvertent blank space before typesetting the footnote number.
+  \unskip
+  \thisfootno\@sf
+  \dofootnote
+}%
+
+% Don't bother with the trickery in plain.tex to not require the
+% footnote text as a parameter.  Our footnotes don't need to be so general.
+%
+% Oh yes, they do; otherwise, @ifset (and anything else that uses
+% \parseargline) fails inside footnotes because the tokens are fixed when
+% the footnote is read.  --karl, 16nov96.
+%
+\gdef\dofootnote{%
+  \insert\footins\bgroup
+  % We want to typeset this text as a normal paragraph, even if the
+  % footnote reference occurs in (for example) a display environment.
+  % So reset some parameters.
+  \hsize=\pagewidth
+  \interlinepenalty\interfootnotelinepenalty
+  \splittopskip\ht\strutbox % top baseline for broken footnotes
+  \splitmaxdepth\dp\strutbox
+  \floatingpenalty\@MM
+  \leftskip\z@skip
+  \rightskip\z@skip
+  \spaceskip\z@skip
+  \xspaceskip\z@skip
+  \parindent\defaultparindent
+  %
+  \smallfonts \rm
+  %
+  % Because we use hanging indentation in footnotes, a @noindent appears
+  % to exdent this text, so make it be a no-op.  makeinfo does not use
+  % hanging indentation so @noindent can still be needed within footnote
+  % text after an @example or the like (not that this is good style).
+  \let\noindent = \relax
+  %
+  % Hang the footnote text off the number.  Use \everypar in case the
+  % footnote extends for more than one paragraph.
+  \everypar = {\hang}%
+  \textindent{\thisfootno}%
+  %
+  % Don't crash into the line above the footnote text.  Since this
+  % expands into a box, it must come within the paragraph, lest it
+  % provide a place where TeX can split the footnote.
+  \footstrut
+  \futurelet\next\fo@t
+}
+}%end \catcode `\@=11
+
+% In case a @footnote appears in a vbox, save the footnote text and create
+% the real \insert just after the vbox finished.  Otherwise, the insertion
+% would be lost.
+% Similarily, if a @footnote appears inside an alignment, save the footnote
+% text to a box and make the \insert when a row of the table is finished.
+% And the same can be done for other insert classes.  --kasal, 16nov03.
+
+% Replace the \insert primitive by a cheating macro.
+% Deeper inside, just make sure that the saved insertions are not spilled
+% out prematurely.
+%
+\def\startsavinginserts{%
+  \ifx \insert\ptexinsert
+    \let\insert\saveinsert
+  \else
+    \let\checkinserts\relax
+  \fi
+}
+
+% This \insert replacement works for both \insert\footins{foo} and
+% \insert\footins\bgroup foo\egroup, but it doesn't work for \insert27{foo}.
+%
+\def\saveinsert#1{%
+  \edef\next{\noexpand\savetobox \makeSAVEname#1}%
+  \afterassignment\next
+  % swallow the left brace
+  \let\temp =
+}
+\def\makeSAVEname#1{\makecsname{SAVE\expandafter\gobble\string#1}}
+\def\savetobox#1{\global\setbox#1 = \vbox\bgroup \unvbox#1}
+
+\def\checksaveins#1{\ifvoid#1\else \placesaveins#1\fi}
+
+\def\placesaveins#1{%
+  \ptexinsert \csname\expandafter\gobblesave\string#1\endcsname
+    {\box#1}%
+}
+
+% eat @SAVE -- beware, all of them have catcode \other:
+{
+  \def\dospecials{\do S\do A\do V\do E} \uncatcodespecials  %  ;-)
+  \gdef\gobblesave @SAVE{}
+}
+
+% initialization:
+\def\newsaveins #1{%
+  \edef\next{\noexpand\newsaveinsX \makeSAVEname#1}%
+  \next
+}
+\def\newsaveinsX #1{%
+  \csname newbox\endcsname #1%
+  \expandafter\def\expandafter\checkinserts\expandafter{\checkinserts
+    \checksaveins #1}%
+}
+
+% initialize:
+\let\checkinserts\empty
+\newsaveins\footins
+\newsaveins\margin
+
+
+% @image.  We use the macros from epsf.tex to support this.
+% If epsf.tex is not installed and @image is used, we complain.
+%
+% Check for and read epsf.tex up front.  If we read it only at @image
+% time, we might be inside a group, and then its definitions would get
+% undone and the next image would fail.
+\openin 1 = epsf.tex
+\ifeof 1 \else
+  % Do not bother showing banner with epsf.tex v2.7k (available in
+  % doc/epsf.tex and on ctan).
+  \def\epsfannounce{\toks0 = }%
+  \input epsf.tex
+\fi
+\closein 1
+%
+% We will only complain once about lack of epsf.tex.
+\newif\ifwarnednoepsf
+\newhelp\noepsfhelp{epsf.tex must be installed for images to
+  work.  It is also included in the Texinfo distribution, or you can get
+  it from ftp://tug.org/tex/epsf.tex.}
+%
+\def\image#1{%
+  \ifx\epsfbox\undefined
+    \ifwarnednoepsf \else
+      \errhelp = \noepsfhelp
+      \errmessage{epsf.tex not found, images will be ignored}%
+      \global\warnednoepsftrue
+    \fi
+  \else
+    \imagexxx #1,,,,,\finish
+  \fi
+}
+%
+% Arguments to @image:
+% #1 is (mandatory) image filename; we tack on .eps extension.
+% #2 is (optional) width, #3 is (optional) height.
+% #4 is (ignored optional) html alt text.
+% #5 is (ignored optional) extension.
+% #6 is just the usual extra ignored arg for parsing this stuff.
+\newif\ifimagevmode
+\def\imagexxx#1,#2,#3,#4,#5,#6\finish{\begingroup
+  \catcode`\^^M = 5     % in case we're inside an example
+  \normalturnoffactive  % allow _ et al. in names
+  % If the image is by itself, center it.
+  \ifvmode
+    \imagevmodetrue
+    \nobreak\bigskip
+    % Usually we'll have text after the image which will insert
+    % \parskip glue, so insert it here too to equalize the space
+    % above and below.
+    \nobreak\vskip\parskip
+    \nobreak
+    \line\bgroup
+  \fi
+  %
+  % Output the image.
+  \ifpdf
+    \dopdfimage{#1}{#2}{#3}%
+  \else
+    % \epsfbox itself resets \epsf?size at each figure.
+    \setbox0 = \hbox{\ignorespaces #2}\ifdim\wd0 > 0pt \epsfxsize=#2\relax \fi
+    \setbox0 = \hbox{\ignorespaces #3}\ifdim\wd0 > 0pt \epsfysize=#3\relax \fi
+    \epsfbox{#1.eps}%
+  \fi
+  %
+  \ifimagevmode \egroup \bigbreak \fi  % space after the image
+\endgroup}
+
+
+% @float FLOATTYPE,LABEL,LOC ... @end float for displayed figures, tables,
+% etc.  We don't actually implement floating yet, we always include the
+% float "here".  But it seemed the best name for the future.
+%
+\envparseargdef\float{\eatcommaspace\eatcommaspace\dofloat#1, , ,\finish}
+
+% There may be a space before second and/or third parameter; delete it.
+\def\eatcommaspace#1, {#1,}
+
+% #1 is the optional FLOATTYPE, the text label for this float, typically
+% "Figure", "Table", "Example", etc.  Can't contain commas.  If omitted,
+% this float will not be numbered and cannot be referred to.
+%
+% #2 is the optional xref label.  Also must be present for the float to
+% be referable.
+%
+% #3 is the optional positioning argument; for now, it is ignored.  It
+% will somehow specify the positions allowed to float to (here, top, bottom).
+%
+% We keep a separate counter for each FLOATTYPE, which we reset at each
+% chapter-level command.
+\let\resetallfloatnos=\empty
+%
+\def\dofloat#1,#2,#3,#4\finish{%
+  \let\thiscaption=\empty
+  \let\thisshortcaption=\empty
+  %
+  % don't lose footnotes inside @float.
+  %
+  % BEWARE: when the floats start float, we have to issue warning whenever an
+  % insert appears inside a float which could possibly float. --kasal, 26may04
+  %
+  \startsavinginserts
+  %
+  % We can't be used inside a paragraph.
+  \par
+  %
+  \vtop\bgroup
+    \def\floattype{#1}%
+    \def\floatlabel{#2}%
+    \def\floatloc{#3}% we do nothing with this yet.
+    %
+    \ifx\floattype\empty
+      \let\safefloattype=\empty
+    \else
+      {%
+        % the floattype might have accents or other special characters,
+        % but we need to use it in a control sequence name.
+        \indexnofonts
+        \turnoffactive
+        \xdef\safefloattype{\floattype}%
+      }%
+    \fi
+    %
+    % If label is given but no type, we handle that as the empty type.
+    \ifx\floatlabel\empty \else
+      % We want each FLOATTYPE to be numbered separately (Figure 1,
+      % Table 1, Figure 2, ...).  (And if no label, no number.)
+      %
+      \expandafter\getfloatno\csname\safefloattype floatno\endcsname
+      \global\advance\floatno by 1
+      %
+      {%
+        % This magic value for \thissection is output by \setref as the
+        % XREFLABEL-title value.  \xrefX uses it to distinguish float
+        % labels (which have a completely different output format) from
+        % node and anchor labels.  And \xrdef uses it to construct the
+        % lists of floats.
+        %
+        \edef\thissection{\floatmagic=\safefloattype}%
+        \setref{\floatlabel}{Yfloat}%
+      }%
+    \fi
+    %
+    % start with \parskip glue, I guess.
+    \vskip\parskip
+    %
+    % Don't suppress indentation if a float happens to start a section.
+    \restorefirstparagraphindent
+}
+
+% we have these possibilities:
+% @float Foo,lbl & @caption{Cap}: Foo 1.1: Cap
+% @float Foo,lbl & no caption:    Foo 1.1
+% @float Foo & @caption{Cap}:     Foo: Cap
+% @float Foo & no caption:        Foo
+% @float ,lbl & Caption{Cap}:     1.1: Cap
+% @float ,lbl & no caption:       1.1
+% @float & @caption{Cap}:         Cap
+% @float & no caption:
+%
+\def\Efloat{%
+    \let\floatident = \empty
+    %
+    % In all cases, if we have a float type, it comes first.
+    \ifx\floattype\empty \else \def\floatident{\floattype}\fi
+    %
+    % If we have an xref label, the number comes next.
+    \ifx\floatlabel\empty \else
+      \ifx\floattype\empty \else % if also had float type, need tie first.
+        \appendtomacro\floatident{\tie}%
+      \fi
+      % the number.
+      \appendtomacro\floatident{\chaplevelprefix\the\floatno}%
+    \fi
+    %
+    % Start the printed caption with what we've constructed in
+    % \floatident, but keep it separate; we need \floatident again.
+    \let\captionline = \floatident
+    %
+    \ifx\thiscaption\empty \else
+      \ifx\floatident\empty \else
+	\appendtomacro\captionline{: }% had ident, so need a colon between
+      \fi
+      %
+      % caption text.
+      \appendtomacro\captionline{\scanexp\thiscaption}%
+    \fi
+    %
+    % If we have anything to print, print it, with space before.
+    % Eventually this needs to become an \insert.
+    \ifx\captionline\empty \else
+      \vskip.5\parskip
+      \captionline
+      %
+      % Space below caption.
+      \vskip\parskip
+    \fi
+    %
+    % If have an xref label, write the list of floats info.  Do this
+    % after the caption, to avoid chance of it being a breakpoint.
+    \ifx\floatlabel\empty \else
+      % Write the text that goes in the lof to the aux file as
+      % \floatlabel-lof.  Besides \floatident, we include the short
+      % caption if specified, else the full caption if specified, else nothing.
+      {%
+        \atdummies
+        %
+        % since we read the caption text in the macro world, where ^^M
+        % is turned into a normal character, we have to scan it back, so
+        % we don't write the literal three characters "^^M" into the aux file.
+	\scanexp{%
+	  \xdef\noexpand\gtemp{%
+	    \ifx\thisshortcaption\empty
+	      \thiscaption
+	    \else
+	      \thisshortcaption
+	    \fi
+	  }%
+	}%
+        \immediate\write\auxfile{@xrdef{\floatlabel-lof}{\floatident
+	  \ifx\gtemp\empty \else : \gtemp \fi}}%
+      }%
+    \fi
+  \egroup  % end of \vtop
+  %
+  % place the captured inserts
+  %
+  % BEWARE: when the floats start floating, we have to issue warning
+  % whenever an insert appears inside a float which could possibly
+  % float. --kasal, 26may04
+  %
+  \checkinserts
+}
+
+% Append the tokens #2 to the definition of macro #1, not expanding either.
+%
+\def\appendtomacro#1#2{%
+  \expandafter\def\expandafter#1\expandafter{#1#2}%
+}
+
+% @caption, @shortcaption
+%
+\def\caption{\docaption\thiscaption}
+\def\shortcaption{\docaption\thisshortcaption}
+\def\docaption{\checkenv\float \bgroup\scanargctxt\defcaption}
+\def\defcaption#1#2{\egroup \def#1{#2}}
+
+% The parameter is the control sequence identifying the counter we are
+% going to use.  Create it if it doesn't exist and assign it to \floatno.
+\def\getfloatno#1{%
+  \ifx#1\relax
+      % Haven't seen this figure type before.
+      \csname newcount\endcsname #1%
+      %
+      % Remember to reset this floatno at the next chap.
+      \expandafter\gdef\expandafter\resetallfloatnos
+        \expandafter{\resetallfloatnos #1=0 }%
+  \fi
+  \let\floatno#1%
+}
+
+% \setref calls this to get the XREFLABEL-snt value.  We want an @xref
+% to the FLOATLABEL to expand to "Figure 3.1".  We call \setref when we
+% first read the @float command.
+%
+\def\Yfloat{\floattype@tie \chaplevelprefix\the\floatno}%
+
+% Magic string used for the XREFLABEL-title value, so \xrefX can
+% distinguish floats from other xref types.
+\def\floatmagic{!!float!!}
+
+% #1 is the control sequence we are passed; we expand into a conditional
+% which is true if #1 represents a float ref.  That is, the magic
+% \thissection value which we \setref above.
+%
+\def\iffloat#1{\expandafter\doiffloat#1==\finish}
+%
+% #1 is (maybe) the \floatmagic string.  If so, #2 will be the
+% (safe) float type for this float.  We set \iffloattype to #2.
+%
+\def\doiffloat#1=#2=#3\finish{%
+  \def\temp{#1}%
+  \def\iffloattype{#2}%
+  \ifx\temp\floatmagic
+}
+
+% @listoffloats FLOATTYPE - print a list of floats like a table of contents.
+%
+\parseargdef\listoffloats{%
+  \def\floattype{#1}% floattype
+  {%
+    % the floattype might have accents or other special characters,
+    % but we need to use it in a control sequence name.
+    \indexnofonts
+    \turnoffactive
+    \xdef\safefloattype{\floattype}%
+  }%
+  %
+  % \xrdef saves the floats as a \do-list in \floatlistSAFEFLOATTYPE.
+  \expandafter\ifx\csname floatlist\safefloattype\endcsname \relax
+    \ifhavexrefs
+      % if the user said @listoffloats foo but never @float foo.
+      \message{\linenumber No `\safefloattype' floats to list.}%
+    \fi
+  \else
+    \begingroup
+      \leftskip=\tocindent  % indent these entries like a toc
+      \let\do=\listoffloatsdo
+      \csname floatlist\safefloattype\endcsname
+    \endgroup
+  \fi
+}
+
+% This is called on each entry in a list of floats.  We're passed the
+% xref label, in the form LABEL-title, which is how we save it in the
+% aux file.  We strip off the -title and look up \XRLABEL-lof, which
+% has the text we're supposed to typeset here.
+%
+% Figures without xref labels will not be included in the list (since
+% they won't appear in the aux file).
+%
+\def\listoffloatsdo#1{\listoffloatsdoentry#1\finish}
+\def\listoffloatsdoentry#1-title\finish{{%
+  % Can't fully expand XR#1-lof because it can contain anything.  Just
+  % pass the control sequence.  On the other hand, XR#1-pg is just the
+  % page number, and we want to fully expand that so we can get a link
+  % in pdf output.
+  \toksA = \expandafter{\csname XR#1-lof\endcsname}%
+  %
+  % use the same \entry macro we use to generate the TOC and index.
+  \edef\writeentry{\noexpand\entry{\the\toksA}{\csname XR#1-pg\endcsname}}%
+  \writeentry
+}}
+
+\message{localization,}
+% and i18n.
+
+% @documentlanguage is usually given very early, just after
+% @setfilename.  If done too late, it may not override everything
+% properly.  Single argument is the language abbreviation.
+% It would be nice if we could set up a hyphenation file here.
+%
+\parseargdef\documentlanguage{%
+  \tex % read txi-??.tex file in plain TeX.
+    % Read the file if it exists.
+    \openin 1 txi-#1.tex
+    \ifeof 1
+      \errhelp = \nolanghelp
+      \errmessage{Cannot read language file txi-#1.tex}%
+    \else
+      \input txi-#1.tex
+    \fi
+    \closein 1
+  \endgroup
+}
+\newhelp\nolanghelp{The given language definition file cannot be found or
+is empty.  Maybe you need to install it?  In the current directory
+should work if nowhere else does.}
+
+
+% @documentencoding should change something in TeX eventually, most
+% likely, but for now just recognize it.
+\let\documentencoding = \comment
+
+
+% Page size parameters.
+%
+\newdimen\defaultparindent \defaultparindent = 15pt
+
+\chapheadingskip = 15pt plus 4pt minus 2pt
+\secheadingskip = 12pt plus 3pt minus 2pt
+\subsecheadingskip = 9pt plus 2pt minus 2pt
+
+% Prevent underfull vbox error messages.
+\vbadness = 10000
+
+% Don't be so finicky about underfull hboxes, either.
+\hbadness = 2000
+
+% Following George Bush, just get rid of widows and orphans.
+\widowpenalty=10000
+\clubpenalty=10000
+
+% Use TeX 3.0's \emergencystretch to help line breaking, but if we're
+% using an old version of TeX, don't do anything.  We want the amount of
+% stretch added to depend on the line length, hence the dependence on
+% \hsize.  We call this whenever the paper size is set.
+%
+\def\setemergencystretch{%
+  \ifx\emergencystretch\thisisundefined
+    % Allow us to assign to \emergencystretch anyway.
+    \def\emergencystretch{\dimen0}%
+  \else
+    \emergencystretch = .15\hsize
+  \fi
+}
+
+% Parameters in order: 1) textheight; 2) textwidth;
+% 3) voffset; 4) hoffset; 5) binding offset; 6) topskip;
+% 7) physical page height; 8) physical page width.
+%
+% We also call \setleading{\textleading}, so the caller should define
+% \textleading.  The caller should also set \parskip.
+%
+\def\internalpagesizes#1#2#3#4#5#6#7#8{%
+  \voffset = #3\relax
+  \topskip = #6\relax
+  \splittopskip = \topskip
+  %
+  \vsize = #1\relax
+  \advance\vsize by \topskip
+  \outervsize = \vsize
+  \advance\outervsize by 2\topandbottommargin
+  \pageheight = \vsize
+  %
+  \hsize = #2\relax
+  \outerhsize = \hsize
+  \advance\outerhsize by 0.5in
+  \pagewidth = \hsize
+  %
+  \normaloffset = #4\relax
+  \bindingoffset = #5\relax
+  %
+  \ifpdf
+    \pdfpageheight #7\relax
+    \pdfpagewidth #8\relax
+  \fi
+  %
+  \setleading{\textleading}
+  %
+  \parindent = \defaultparindent
+  \setemergencystretch
+}
+
+% @letterpaper (the default).
+\def\letterpaper{{\globaldefs = 1
+  \parskip = 3pt plus 2pt minus 1pt
+  \textleading = 13.2pt
+  %
+  % If page is nothing but text, make it come out even.
+  \internalpagesizes{46\baselineskip}{6in}%
+                    {\voffset}{.25in}%
+                    {\bindingoffset}{36pt}%
+                    {11in}{8.5in}%
+}}
+
+% Use @smallbook to reset parameters for 7x9.25 trim size.
+\def\smallbook{{\globaldefs = 1
+  \parskip = 2pt plus 1pt
+  \textleading = 12pt
+  %
+  \internalpagesizes{7.5in}{5in}%
+                    {\voffset}{.25in}%
+                    {\bindingoffset}{16pt}%
+                    {9.25in}{7in}%
+  %
+  \lispnarrowing = 0.3in
+  \tolerance = 700
+  \hfuzz = 1pt
+  \contentsrightmargin = 0pt
+  \defbodyindent = .5cm
+}}
+
+% Use @smallerbook to reset parameters for 6x9 trim size.
+% (Just testing, parameters still in flux.)
+\def\smallerbook{{\globaldefs = 1
+  \parskip = 1.5pt plus 1pt
+  \textleading = 12pt
+  %
+  \internalpagesizes{7.4in}{4.8in}%
+                    {-.2in}{-.4in}%
+                    {0pt}{14pt}%
+                    {9in}{6in}%
+  %
+  \lispnarrowing = 0.25in
+  \tolerance = 700
+  \hfuzz = 1pt
+  \contentsrightmargin = 0pt
+  \defbodyindent = .4cm
+}}
+
+% Use @afourpaper to print on European A4 paper.
+\def\afourpaper{{\globaldefs = 1
+  \parskip = 3pt plus 2pt minus 1pt
+  \textleading = 13.2pt
+  %
+  % Double-side printing via postscript on Laserjet 4050
+  % prints double-sided nicely when \bindingoffset=10mm and \hoffset=-6mm.
+  % To change the settings for a different printer or situation, adjust
+  % \normaloffset until the front-side and back-side texts align.  Then
+  % do the same for \bindingoffset.  You can set these for testing in
+  % your texinfo source file like this:
+  % @tex
+  % \global\normaloffset = -6mm
+  % \global\bindingoffset = 10mm
+  % @end tex
+  \internalpagesizes{51\baselineskip}{160mm}
+                    {\voffset}{\hoffset}%
+                    {\bindingoffset}{44pt}%
+                    {297mm}{210mm}%
+  %
+  \tolerance = 700
+  \hfuzz = 1pt
+  \contentsrightmargin = 0pt
+  \defbodyindent = 5mm
+}}
+
+% Use @afivepaper to print on European A5 paper.
+% From romildo@urano.iceb.ufop.br, 2 July 2000.
+% He also recommends making @example and @lisp be small.
+\def\afivepaper{{\globaldefs = 1
+  \parskip = 2pt plus 1pt minus 0.1pt
+  \textleading = 12.5pt
+  %
+  \internalpagesizes{160mm}{120mm}%
+                    {\voffset}{\hoffset}%
+                    {\bindingoffset}{8pt}%
+                    {210mm}{148mm}%
+  %
+  \lispnarrowing = 0.2in
+  \tolerance = 800
+  \hfuzz = 1.2pt
+  \contentsrightmargin = 0pt
+  \defbodyindent = 2mm
+  \tableindent = 12mm
+}}
+
+% A specific text layout, 24x15cm overall, intended for A4 paper.
+\def\afourlatex{{\globaldefs = 1
+  \afourpaper
+  \internalpagesizes{237mm}{150mm}%
+                    {\voffset}{4.6mm}%
+                    {\bindingoffset}{7mm}%
+                    {297mm}{210mm}%
+  %
+  % Must explicitly reset to 0 because we call \afourpaper.
+  \globaldefs = 0
+}}
+
+% Use @afourwide to print on A4 paper in landscape format.
+\def\afourwide{{\globaldefs = 1
+  \afourpaper
+  \internalpagesizes{241mm}{165mm}%
+                    {\voffset}{-2.95mm}%
+                    {\bindingoffset}{7mm}%
+                    {297mm}{210mm}%
+  \globaldefs = 0
+}}
+
+% @pagesizes TEXTHEIGHT[,TEXTWIDTH]
+% Perhaps we should allow setting the margins, \topskip, \parskip,
+% and/or leading, also. Or perhaps we should compute them somehow.
+%
+\parseargdef\pagesizes{\pagesizesyyy #1,,\finish}
+\def\pagesizesyyy#1,#2,#3\finish{{%
+  \setbox0 = \hbox{\ignorespaces #2}\ifdim\wd0 > 0pt \hsize=#2\relax \fi
+  \globaldefs = 1
+  %
+  \parskip = 3pt plus 2pt minus 1pt
+  \setleading{\textleading}%
+  %
+  \dimen0 = #1
+  \advance\dimen0 by \voffset
+  %
+  \dimen2 = \hsize
+  \advance\dimen2 by \normaloffset
+  %
+  \internalpagesizes{#1}{\hsize}%
+                    {\voffset}{\normaloffset}%
+                    {\bindingoffset}{44pt}%
+                    {\dimen0}{\dimen2}%
+}}
+
+% Set default to letter.
+%
+\letterpaper
+
+
+\message{and turning on texinfo input format.}
+
+% Define macros to output various characters with catcode for normal text.
+\catcode`\"=\other
+\catcode`\~=\other
+\catcode`\^=\other
+\catcode`\_=\other
+\catcode`\|=\other
+\catcode`\<=\other
+\catcode`\>=\other
+\catcode`\+=\other
+\catcode`\$=\other
+\def\normaldoublequote{"}
+\def\normaltilde{~}
+\def\normalcaret{^}
+\def\normalunderscore{_}
+\def\normalverticalbar{|}
+\def\normalless{<}
+\def\normalgreater{>}
+\def\normalplus{+}
+\def\normaldollar{$}%$ font-lock fix
+
+% This macro is used to make a character print one way in \tt
+% (where it can probably be output as-is), and another way in other fonts,
+% where something hairier probably needs to be done.
+%
+% #1 is what to print if we are indeed using \tt; #2 is what to print
+% otherwise.  Since all the Computer Modern typewriter fonts have zero
+% interword stretch (and shrink), and it is reasonable to expect all
+% typewriter fonts to have this, we can check that font parameter.
+%
+\def\ifusingtt#1#2{\ifdim \fontdimen3\font=0pt #1\else #2\fi}
+
+% Same as above, but check for italic font.  Actually this also catches
+% non-italic slanted fonts since it is impossible to distinguish them from
+% italic fonts.  But since this is only used by $ and it uses \sl anyway
+% this is not a problem.
+\def\ifusingit#1#2{\ifdim \fontdimen1\font>0pt #1\else #2\fi}
+
+% Turn off all special characters except @
+% (and those which the user can use as if they were ordinary).
+% Most of these we simply print from the \tt font, but for some, we can
+% use math or other variants that look better in normal text.
+
+\catcode`\"=\active
+\def\activedoublequote{{\tt\char34}}
+\let"=\activedoublequote
+\catcode`\~=\active
+\def~{{\tt\char126}}
+\chardef\hat=`\^
+\catcode`\^=\active
+\def^{{\tt \hat}}
+
+\catcode`\_=\active
+\def_{\ifusingtt\normalunderscore\_}
+\let\realunder=_
+% Subroutine for the previous macro.
+\def\_{\leavevmode \kern.07em \vbox{\hrule width.3em height.1ex}\kern .07em }
+
+\catcode`\|=\active
+\def|{{\tt\char124}}
+\chardef \less=`\<
+\catcode`\<=\active
+\def<{{\tt \less}}
+\chardef \gtr=`\>
+\catcode`\>=\active
+\def>{{\tt \gtr}}
+\catcode`\+=\active
+\def+{{\tt \char 43}}
+\catcode`\$=\active
+\def${\ifusingit{{\sl\$}}\normaldollar}%$ font-lock fix
+
+% If a .fmt file is being used, characters that might appear in a file
+% name cannot be active until we have parsed the command line.
+% So turn them off again, and have \everyjob (or @setfilename) turn them on.
+% \otherifyactive is called near the end of this file.
+\def\otherifyactive{\catcode`+=\other \catcode`\_=\other}
+
+% Used sometimes to turn off (effectively) the active characters even after
+% parsing them.
+\def\turnoffactive{%
+  \normalturnoffactive
+  \otherbackslash
+}
+
+\catcode`\@=0
+
+% \backslashcurfont outputs one backslash character in current font,
+% as in \char`\\.
+\global\chardef\backslashcurfont=`\\
+\global\let\rawbackslashxx=\backslashcurfont  % let existing .??s files work
+
+% \realbackslash is an actual character `\' with catcode other, and
+% \doublebackslash is two of them (for the pdf outlines).
+{\catcode`\\=\other @gdef@realbackslash{\} @gdef@doublebackslash{\\}}
+
+% In texinfo, backslash is an active character; it prints the backslash
+% in fixed width font.
+\catcode`\\=\active
+@def@normalbackslash{{@tt@backslashcurfont}}
+% On startup, @fixbackslash assigns:
+%  @let \ = @normalbackslash
+
+% \rawbackslash defines an active \ to do \backslashcurfont.
+% \otherbackslash defines an active \ to be a literal `\' character with
+% catcode other.
+@gdef@rawbackslash{@let\=@backslashcurfont}
+@gdef@otherbackslash{@let\=@realbackslash}
+
+% Same as @turnoffactive except outputs \ as {\tt\char`\\} instead of
+% the literal character `\'.
+% 
+@def@normalturnoffactive{%
+  @let\=@normalbackslash
+  @let"=@normaldoublequote
+  @let~=@normaltilde
+  @let^=@normalcaret
+  @let_=@normalunderscore
+  @let|=@normalverticalbar
+  @let<=@normalless
+  @let>=@normalgreater
+  @let+=@normalplus
+  @let$=@normaldollar %$ font-lock fix
+  @unsepspaces
+}
+
+% Make _ and + \other characters, temporarily.
+% This is canceled by @fixbackslash.
+@otherifyactive
+
+% If a .fmt file is being used, we don't want the `\input texinfo' to show up.
+% That is what \eatinput is for; after that, the `\' should revert to printing
+% a backslash.
+%
+@gdef@eatinput input texinfo{@fixbackslash}
+@global@let\ = @eatinput
+
+% On the other hand, perhaps the file did not have a `\input texinfo'. Then
+% the first `\' in the file would cause an error. This macro tries to fix
+% that, assuming it is called before the first `\' could plausibly occur.
+% Also turn back on active characters that might appear in the input
+% file name, in case not using a pre-dumped format.
+%
+@gdef@fixbackslash{%
+  @ifx\@eatinput @let\ = @normalbackslash @fi
+  @catcode`+=@active
+  @catcode`@_=@active
+}
+
+% Say @foo, not \foo, in error messages.
+@escapechar = `@@
+
+% These look ok in all fonts, so just make them not special.
+@catcode`@& = @other
+@catcode`@# = @other
+@catcode`@% = @other
+
+
+@c Local variables:
+@c eval: (add-hook 'write-file-hooks 'time-stamp)
+@c page-delimiter: "^\\\\message"
+@c time-stamp-start: "def\\\\texinfoversion{"
+@c time-stamp-format: "%:y-%02m-%02d.%02H"
+@c time-stamp-end: "}"
+@c End:
+
+@c vim:sw=2:
+
+@ignore
+   arch-tag: e1b36e32-c96e-4135-a41a-0b2efa2ea115
+@end ignore
diff --git a/src/bin/m4/doc/version.texi b/src/bin/m4/doc/version.texi
new file mode 100644
index 0000000000..c9d4e2fb98
--- /dev/null
+++ b/src/bin/m4/doc/version.texi
@@ -0,0 +1,4 @@
+@set UPDATED 20 November 2006
+@set UPDATED-MONTH November 2006
+@set EDITION 1.4.8
+@set VERSION 1.4.8
diff --git a/src/bin/m4/lib/Jamfile b/src/bin/m4/lib/Jamfile
new file mode 100644
index 0000000000..ae3f5a3401
--- /dev/null
+++ b/src/bin/m4/lib/Jamfile
@@ -0,0 +1,34 @@
+SubDir HAIKU_TOP src bin m4 lib ;
+
+SubDirCcFlags -DHAVE_CONFIG_H ;
+
+SubDirSysHdrs $(SUBDIR) ;
+SubDirSysHdrs [ FDirName $(SUBDIR) $(DOTDOT) ] ;
+
+StaticLibrary libm4.a : 
+	__fpending.c
+	allocsa.c
+	clean-temp.c
+	cloexec.c
+	close-stream.c
+	closeout.c
+	dup-safer.c
+	error.c
+	exitfail.c
+	fatal-signal.c
+	fd-safer.c
+	fopen-safer.c
+	gl_avltree_oset.c
+	gl_linkedhash_list.c
+	mkdtemp.c
+	mkstemp-safer.c
+	quotearg.c
+	strstr.c
+	tempname.c
+	tmpdir.c
+	verror.c
+	xalloc-die.c
+	xasprintf.c
+	xmalloc.c
+	xvasprintf.c
+;
diff --git a/src/bin/m4/lib/Makefile.am b/src/bin/m4/lib/Makefile.am
new file mode 100644
index 0000000000..8a0fe98fe6
--- /dev/null
+++ b/src/bin/m4/lib/Makefile.am
@@ -0,0 +1,558 @@
+## DO NOT EDIT! GENERATED AUTOMATICALLY!
+## Process this file with automake to produce Makefile.in.
+# Copyright (C) 2004-2006 Free Software Foundation, Inc.
+#
+# This file is free software, distributed under the terms of the GNU
+# General Public License.  As a special exception to the GNU General
+# Public License, this file may be distributed as part of a program
+# that contains a configuration script generated by Autoconf, under
+# the same distribution terms as the rest of that program.
+#
+# Generated by gnulib-tool.
+# Reproduce by: gnulib-tool --import --dir=. --lib=libm4 --source-base=lib --m4-base=m4 --doc-base=doc --aux-dir=. --no-libtool --macro-prefix=M4 avltree-oset binary-io clean-temp cloexec close-stream closeout config-h error fdl fopen-safer free gendocs getopt gnupload mkstemp obstack regex stdbool stdlib-safer strstr strtol unlocked-io verror xalloc xvasprintf
+
+AUTOMAKE_OPTIONS = 1.5 gnits
+
+noinst_LIBRARIES = libm4.a
+
+libm4_a_SOURCES =
+libm4_a_LIBADD = $(M4_LIBOBJS)
+libm4_a_DEPENDENCIES = $(M4_LIBOBJS)
+EXTRA_libm4_a_SOURCES =
+noinst_HEADERS =
+EXTRA_DIST =
+BUILT_SOURCES =
+SUFFIXES =
+MOSTLYCLEANFILES = core *.stackdump
+MOSTLYCLEANDIRS =
+CLEANFILES =
+DISTCLEANFILES =
+MAINTAINERCLEANFILES =
+
+AM_CPPFLAGS =
+
+## begin gnulib module alloca
+
+
+EXTRA_DIST += alloca.c
+
+EXTRA_libm4_a_SOURCES += alloca.c
+
+libm4_a_LIBADD += @ALLOCA@
+libm4_a_DEPENDENCIES += @ALLOCA@
+## end   gnulib module alloca
+
+## begin gnulib module alloca-opt
+
+BUILT_SOURCES += $(ALLOCA_H)
+
+# We need the following in order to create <alloca.h> when the system
+# doesn't have one that works with the given compiler.
+alloca.h: alloca_.h
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  cat $(srcdir)/alloca_.h; \
+	} > $@-t
+	mv -f $@-t $@
+MOSTLYCLEANFILES += alloca.h alloca.h-t
+
+EXTRA_DIST += alloca_.h
+
+## end   gnulib module alloca-opt
+
+## begin gnulib module allocsa
+
+libm4_a_SOURCES += allocsa.h allocsa.c
+
+EXTRA_DIST += allocsa.valgrind
+
+## end   gnulib module allocsa
+
+## begin gnulib module avltree-oset
+
+libm4_a_SOURCES += gl_avltree_oset.h gl_avltree_oset.c gl_anytree_oset.h
+
+## end   gnulib module avltree-oset
+
+## begin gnulib module binary-io
+
+libm4_a_SOURCES += binary-io.h
+
+## end   gnulib module binary-io
+
+## begin gnulib module clean-temp
+
+libm4_a_SOURCES += clean-temp.h clean-temp.c
+
+## end   gnulib module clean-temp
+
+## begin gnulib module cloexec
+
+
+EXTRA_DIST += cloexec.c cloexec.h
+
+EXTRA_libm4_a_SOURCES += cloexec.c
+
+## end   gnulib module cloexec
+
+## begin gnulib module close-stream
+
+
+EXTRA_DIST += close-stream.c close-stream.h
+
+EXTRA_libm4_a_SOURCES += close-stream.c
+
+## end   gnulib module close-stream
+
+## begin gnulib module closeout
+
+
+EXTRA_DIST += closeout.c closeout.h
+
+EXTRA_libm4_a_SOURCES += closeout.c
+
+## end   gnulib module closeout
+
+## begin gnulib module error
+
+
+EXTRA_DIST += error.c error.h
+
+EXTRA_libm4_a_SOURCES += error.c
+
+## end   gnulib module error
+
+## begin gnulib module exit
+
+libm4_a_SOURCES += exit.h
+
+## end   gnulib module exit
+
+## begin gnulib module exitfail
+
+
+EXTRA_DIST += exitfail.c exitfail.h
+
+EXTRA_libm4_a_SOURCES += exitfail.c
+
+## end   gnulib module exitfail
+
+## begin gnulib module fatal-signal
+
+libm4_a_SOURCES += fatal-signal.h fatal-signal.c
+
+## end   gnulib module fatal-signal
+
+## begin gnulib module fopen-safer
+
+
+EXTRA_DIST += fopen-safer.c stdio--.h stdio-safer.h
+
+EXTRA_libm4_a_SOURCES += fopen-safer.c
+
+## end   gnulib module fopen-safer
+
+## begin gnulib module fpending
+
+
+EXTRA_DIST += __fpending.c __fpending.h
+
+EXTRA_libm4_a_SOURCES += __fpending.c
+
+## end   gnulib module fpending
+
+## begin gnulib module free
+
+
+EXTRA_DIST += free.c
+
+EXTRA_libm4_a_SOURCES += free.c
+
+## end   gnulib module free
+
+## begin gnulib module getopt
+
+BUILT_SOURCES += $(GETOPT_H)
+
+# We need the following in order to create <getopt.h> when the system
+# doesn't have one that works with the given compiler.
+getopt.h: getopt_.h
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  cat $(srcdir)/getopt_.h; \
+	} > $@-t
+	mv -f $@-t $@
+MOSTLYCLEANFILES += getopt.h getopt.h-t
+
+EXTRA_DIST += getopt.c getopt1.c getopt_.h getopt_int.h
+
+EXTRA_libm4_a_SOURCES += getopt.c getopt1.c
+
+## end   gnulib module getopt
+
+## begin gnulib module gettext-h
+
+libm4_a_SOURCES += gettext.h
+
+## end   gnulib module gettext-h
+
+## begin gnulib module linkedhash-list
+
+libm4_a_SOURCES += gl_linkedhash_list.h gl_linkedhash_list.c gl_anyhash_list1.h gl_anyhash_list2.h gl_anylinked_list1.h gl_anylinked_list2.h
+
+## end   gnulib module linkedhash-list
+
+## begin gnulib module list
+
+libm4_a_SOURCES += gl_list.h gl_list.c
+
+## end   gnulib module list
+
+## begin gnulib module malloc
+
+
+EXTRA_DIST += malloc.c
+
+EXTRA_libm4_a_SOURCES += malloc.c
+
+## end   gnulib module malloc
+
+## begin gnulib module mbchar
+
+
+EXTRA_DIST += mbchar.c mbchar.h
+
+EXTRA_libm4_a_SOURCES += mbchar.c
+
+## end   gnulib module mbchar
+
+## begin gnulib module mbuiter
+
+libm4_a_SOURCES += mbuiter.h
+
+## end   gnulib module mbuiter
+
+## begin gnulib module memchr
+
+
+EXTRA_DIST += memchr.c
+
+EXTRA_libm4_a_SOURCES += memchr.c
+
+## end   gnulib module memchr
+
+## begin gnulib module mkdtemp
+
+
+EXTRA_DIST += mkdtemp.c mkdtemp.h
+
+EXTRA_libm4_a_SOURCES += mkdtemp.c
+
+## end   gnulib module mkdtemp
+
+## begin gnulib module mkstemp
+
+
+EXTRA_DIST += mkstemp.c mkstemp.h
+
+EXTRA_libm4_a_SOURCES += mkstemp.c
+
+## end   gnulib module mkstemp
+
+## begin gnulib module obstack
+
+
+EXTRA_DIST += obstack.c obstack.h
+
+EXTRA_libm4_a_SOURCES += obstack.c
+
+## end   gnulib module obstack
+
+## begin gnulib module oset
+
+libm4_a_SOURCES += gl_oset.h gl_oset.c
+
+## end   gnulib module oset
+
+## begin gnulib module pathmax
+
+
+EXTRA_DIST += pathmax.h
+
+## end   gnulib module pathmax
+
+## begin gnulib module quotearg
+
+
+EXTRA_DIST += quotearg.c quotearg.h
+
+EXTRA_libm4_a_SOURCES += quotearg.c
+
+## end   gnulib module quotearg
+
+## begin gnulib module regex
+
+
+EXTRA_DIST += regcomp.c regex.c regex.h regex_internal.c regex_internal.h regexec.c
+
+EXTRA_libm4_a_SOURCES += regcomp.c regex.c regex_internal.c regexec.c
+
+## end   gnulib module regex
+
+## begin gnulib module sigprocmask
+
+
+EXTRA_DIST += sigprocmask.c sigprocmask.h
+
+EXTRA_libm4_a_SOURCES += sigprocmask.c
+
+## end   gnulib module sigprocmask
+
+## begin gnulib module size_max
+
+libm4_a_SOURCES += size_max.h
+
+## end   gnulib module size_max
+
+## begin gnulib module stdbool
+
+BUILT_SOURCES += $(STDBOOL_H)
+
+# We need the following in order to create <stdbool.h> when the system
+# doesn't have one that works.
+stdbool.h: stdbool_.h
+	rm -f $@-t $@
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's/@''HAVE__BOOL''@/$(HAVE__BOOL)/g' < $(srcdir)/stdbool_.h; \
+	} > $@-t
+	mv $@-t $@
+MOSTLYCLEANFILES += stdbool.h stdbool.h-t
+
+EXTRA_DIST += stdbool_.h
+
+## end   gnulib module stdbool
+
+## begin gnulib module stdint
+
+BUILT_SOURCES += $(STDINT_H)
+
+# We need the following in order to create <stdint.h> when the system
+# doesn't have one that works with the given compiler.
+stdint.h: stdint_.h
+	rm -f $@-t $@
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's/@''HAVE_WCHAR_H''@/$(HAVE_WCHAR_H)/g' \
+	      -e 's/@''HAVE_STDINT_H''@/$(HAVE_STDINT_H)/g' \
+	      -e 's|@''ABSOLUTE_STDINT_H''@|$(ABSOLUTE_STDINT_H)|g' \
+	      -e 's/@''HAVE_SYS_TYPES_H''@/$(HAVE_SYS_TYPES_H)/g' \
+	      -e 's/@''HAVE_INTTYPES_H''@/$(HAVE_INTTYPES_H)/g' \
+	      -e 's/@''HAVE_SYS_INTTYPES_H''@/$(HAVE_SYS_INTTYPES_H)/g' \
+	      -e 's/@''HAVE_SYS_BITYPES_H''@/$(HAVE_SYS_BITYPES_H)/g' \
+	      -e 's/@''HAVE_LONG_LONG_INT''@/$(HAVE_LONG_LONG_INT)/g' \
+	      -e 's/@''HAVE_UNSIGNED_LONG_LONG_INT''@/$(HAVE_UNSIGNED_LONG_LONG_INT)/g' \
+	      -e 's/@''BITSIZEOF_PTRDIFF_T''@/$(BITSIZEOF_PTRDIFF_T)/g' \
+	      -e 's/@''PTRDIFF_T_SUFFIX''@/$(PTRDIFF_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_SIG_ATOMIC_T''@/$(BITSIZEOF_SIG_ATOMIC_T)/g' \
+	      -e 's/@''HAVE_SIGNED_SIG_ATOMIC_T''@/$(HAVE_SIGNED_SIG_ATOMIC_T)/g' \
+	      -e 's/@''SIG_ATOMIC_T_SUFFIX''@/$(SIG_ATOMIC_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_SIZE_T''@/$(BITSIZEOF_SIZE_T)/g' \
+	      -e 's/@''SIZE_T_SUFFIX''@/$(SIZE_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_WCHAR_T''@/$(BITSIZEOF_WCHAR_T)/g' \
+	      -e 's/@''HAVE_SIGNED_WCHAR_T''@/$(HAVE_SIGNED_WCHAR_T)/g' \
+	      -e 's/@''WCHAR_T_SUFFIX''@/$(WCHAR_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_WINT_T''@/$(BITSIZEOF_WINT_T)/g' \
+	      -e 's/@''HAVE_SIGNED_WINT_T''@/$(HAVE_SIGNED_WINT_T)/g' \
+	      -e 's/@''WINT_T_SUFFIX''@/$(WINT_T_SUFFIX)/g' \
+	      < $(srcdir)/stdint_.h; \
+	} > $@-t
+	mv $@-t $@
+MOSTLYCLEANFILES += stdint.h stdint.h-t
+
+EXTRA_DIST += stdint_.h
+
+## end   gnulib module stdint
+
+## begin gnulib module stdlib-safer
+
+
+EXTRA_DIST += mkstemp-safer.c stdlib--.h stdlib-safer.h
+
+EXTRA_libm4_a_SOURCES += mkstemp-safer.c
+
+## end   gnulib module stdlib-safer
+
+## begin gnulib module strcase
+
+
+EXTRA_DIST += strcase.h strcasecmp.c strncasecmp.c
+
+EXTRA_libm4_a_SOURCES += strcasecmp.c strncasecmp.c
+
+## end   gnulib module strcase
+
+## begin gnulib module strnlen1
+
+libm4_a_SOURCES += strnlen1.h strnlen1.c
+
+## end   gnulib module strnlen1
+
+## begin gnulib module strstr
+
+
+EXTRA_DIST += strstr.c strstr.h
+
+EXTRA_libm4_a_SOURCES += strstr.c
+
+## end   gnulib module strstr
+
+## begin gnulib module strtol
+
+
+EXTRA_DIST += strtol.c
+
+EXTRA_libm4_a_SOURCES += strtol.c
+
+## end   gnulib module strtol
+
+## begin gnulib module sys_stat
+
+BUILT_SOURCES += $(SYS_STAT_H)
+
+# We need the following in order to create <sys/stat.h> when the system
+# has one that is incomplete.
+sys/stat.h: stat_.h
+	test -d sys || mkdir sys
+	rm -f $@-t $@
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's|@''ABSOLUTE_SYS_STAT_H''@|$(ABSOLUTE_SYS_STAT_H)|g' \
+	      < $(srcdir)/stat_.h; \
+	} > $@-t
+	mv $@-t $@
+MOSTLYCLEANFILES += sys/stat.h sys/stat.h-t
+MOSTLYCLEANDIRS += sys
+
+EXTRA_DIST += stat_.h
+
+## end   gnulib module sys_stat
+
+## begin gnulib module tempname
+
+
+EXTRA_DIST += tempname.c tempname.h
+
+EXTRA_libm4_a_SOURCES += tempname.c
+
+## end   gnulib module tempname
+
+## begin gnulib module tmpdir
+
+libm4_a_SOURCES += tmpdir.h tmpdir.c
+
+## end   gnulib module tmpdir
+
+## begin gnulib module unistd
+
+BUILT_SOURCES += $(UNISTD_H)
+
+# We need the following in order to create an empty placeholder for
+# <unistd.h> when the system doesn't have one.
+unistd.h:
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  echo '/* Empty placeholder for $@.  */'; \
+	} > $@
+MOSTLYCLEANFILES += unistd.h
+
+## end   gnulib module unistd
+
+## begin gnulib module unistd-safer
+
+
+EXTRA_DIST += dup-safer.c fd-safer.c pipe-safer.c unistd--.h unistd-safer.h
+
+EXTRA_libm4_a_SOURCES += dup-safer.c fd-safer.c pipe-safer.c
+
+## end   gnulib module unistd-safer
+
+## begin gnulib module unlocked-io
+
+
+EXTRA_DIST += unlocked-io.h
+
+## end   gnulib module unlocked-io
+
+## begin gnulib module vasnprintf
+
+
+EXTRA_DIST += asnprintf.c printf-args.c printf-args.h printf-parse.c printf-parse.h vasnprintf.c vasnprintf.h
+
+EXTRA_libm4_a_SOURCES += asnprintf.c printf-args.c printf-parse.c vasnprintf.c
+
+## end   gnulib module vasnprintf
+
+## begin gnulib module vasprintf
+
+
+EXTRA_DIST += asprintf.c vasprintf.c vasprintf.h
+
+EXTRA_libm4_a_SOURCES += asprintf.c vasprintf.c
+
+## end   gnulib module vasprintf
+
+## begin gnulib module verify
+
+libm4_a_SOURCES += verify.h
+
+## end   gnulib module verify
+
+## begin gnulib module verror
+
+libm4_a_SOURCES += verror.h verror.c
+
+## end   gnulib module verror
+
+## begin gnulib module wcwidth
+
+libm4_a_SOURCES += wcwidth.h
+
+## end   gnulib module wcwidth
+
+## begin gnulib module xalloc
+
+
+EXTRA_DIST += xalloc.h xmalloc.c
+
+EXTRA_libm4_a_SOURCES += xmalloc.c
+
+## end   gnulib module xalloc
+
+## begin gnulib module xalloc-die
+
+libm4_a_SOURCES += xalloc-die.c
+
+## end   gnulib module xalloc-die
+
+## begin gnulib module xallocsa
+
+libm4_a_SOURCES += xallocsa.h xallocsa.c
+
+## end   gnulib module xallocsa
+
+## begin gnulib module xsize
+
+libm4_a_SOURCES += xsize.h
+
+## end   gnulib module xsize
+
+## begin gnulib module xvasprintf
+
+libm4_a_SOURCES += xvasprintf.h xvasprintf.c xasprintf.c
+
+EXTRA_DIST += xalloc.h
+
+## end   gnulib module xvasprintf
+
+
+mostlyclean-local: mostlyclean-generic
+	@for dir in '' $(MOSTLYCLEANDIRS); do \
+	  if test -n "$$dir" && test -d $$dir; then \
+	    echo "rmdir $$dir"; rmdir $$dir; \
+	  fi; \
+	done
diff --git a/src/bin/m4/lib/Makefile.in b/src/bin/m4/lib/Makefile.in
new file mode 100644
index 0000000000..08a7af9d93
--- /dev/null
+++ b/src/bin/m4/lib/Makefile.in
@@ -0,0 +1,692 @@
+# Makefile.in generated by automake 1.10 from Makefile.am.
+# @configure_input@
+
+# Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
+# 2003, 2004, 2005, 2006  Free Software Foundation, Inc.
+# This Makefile.in is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+@SET_MAKE@
+
+# Copyright (C) 2004-2006 Free Software Foundation, Inc.
+#
+# This file is free software, distributed under the terms of the GNU
+# General Public License.  As a special exception to the GNU General
+# Public License, this file may be distributed as part of a program
+# that contains a configuration script generated by Autoconf, under
+# the same distribution terms as the rest of that program.
+#
+# Generated by gnulib-tool.
+# Reproduce by: gnulib-tool --import --dir=. --lib=libm4 --source-base=lib --m4-base=m4 --doc-base=doc --aux-dir=. --no-libtool --macro-prefix=M4 avltree-oset binary-io clean-temp cloexec close-stream closeout config-h error fdl fopen-safer free gendocs getopt gnupload mkstemp obstack regex stdbool stdlib-safer strstr strtol unlocked-io verror xalloc xvasprintf
+
+
+VPATH = @srcdir@
+pkgdatadir = $(datadir)/@PACKAGE@
+pkglibdir = $(libdir)/@PACKAGE@
+pkgincludedir = $(includedir)/@PACKAGE@
+am__cd = CDPATH="$${ZSH_VERSION+.}$(PATH_SEPARATOR)" && cd
+install_sh_DATA = $(install_sh) -c -m 644
+install_sh_PROGRAM = $(install_sh) -c
+install_sh_SCRIPT = $(install_sh) -c
+INSTALL_HEADER = $(INSTALL_DATA)
+transform = $(program_transform_name)
+NORMAL_INSTALL = :
+PRE_INSTALL = :
+POST_INSTALL = :
+NORMAL_UNINSTALL = :
+PRE_UNINSTALL = :
+POST_UNINSTALL = :
+build_triplet = @build@
+host_triplet = @host@
+subdir = lib
+DIST_COMMON = $(noinst_HEADERS) $(srcdir)/Makefile.am \
+	$(srcdir)/Makefile.in $(srcdir)/config.hin alloca.c
+ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
+am__aclocal_m4_deps = $(top_srcdir)/m4/absolute-header.m4 \
+	$(top_srcdir)/m4/alloca.m4 $(top_srcdir)/m4/allocsa.m4 \
+	$(top_srcdir)/m4/cloexec.m4 $(top_srcdir)/m4/close-stream.m4 \
+	$(top_srcdir)/m4/closeout.m4 $(top_srcdir)/m4/codeset.m4 \
+	$(top_srcdir)/m4/config-h.m4 $(top_srcdir)/m4/eealloc.m4 \
+	$(top_srcdir)/m4/eoverflow.m4 $(top_srcdir)/m4/error.m4 \
+	$(top_srcdir)/m4/exitfail.m4 $(top_srcdir)/m4/extensions.m4 \
+	$(top_srcdir)/m4/fatal-signal.m4 $(top_srcdir)/m4/fpending.m4 \
+	$(top_srcdir)/m4/free.m4 $(top_srcdir)/m4/getopt.m4 \
+	$(top_srcdir)/m4/gl_list.m4 $(top_srcdir)/m4/gnulib-comp.m4 \
+	$(top_srcdir)/m4/inline.m4 $(top_srcdir)/m4/intmax_t.m4 \
+	$(top_srcdir)/m4/inttypes_h.m4 $(top_srcdir)/m4/longdouble.m4 \
+	$(top_srcdir)/m4/longlong.m4 $(top_srcdir)/m4/mbchar.m4 \
+	$(top_srcdir)/m4/mbiter.m4 $(top_srcdir)/m4/mbrtowc.m4 \
+	$(top_srcdir)/m4/mbstate_t.m4 $(top_srcdir)/m4/memchr.m4 \
+	$(top_srcdir)/m4/mkdtemp.m4 $(top_srcdir)/m4/mkstemp.m4 \
+	$(top_srcdir)/m4/pathmax.m4 $(top_srcdir)/m4/quotearg.m4 \
+	$(top_srcdir)/m4/regex.m4 $(top_srcdir)/m4/sig_atomic_t.m4 \
+	$(top_srcdir)/m4/signalblocking.m4 \
+	$(top_srcdir)/m4/size_max.m4 $(top_srcdir)/m4/ssize_t.m4 \
+	$(top_srcdir)/m4/stdarg.m4 $(top_srcdir)/m4/stdbool.m4 \
+	$(top_srcdir)/m4/stdint.m4 $(top_srcdir)/m4/stdint_h.m4 \
+	$(top_srcdir)/m4/stdio-safer.m4 \
+	$(top_srcdir)/m4/stdlib-safer.m4 $(top_srcdir)/m4/strcase.m4 \
+	$(top_srcdir)/m4/strstr.m4 $(top_srcdir)/m4/strtol.m4 \
+	$(top_srcdir)/m4/sys_stat_h.m4 $(top_srcdir)/m4/tempname.m4 \
+	$(top_srcdir)/m4/tmpdir.m4 $(top_srcdir)/m4/ulonglong.m4 \
+	$(top_srcdir)/m4/unistd-safer.m4 $(top_srcdir)/m4/unistd_h.m4 \
+	$(top_srcdir)/m4/unlocked-io.m4 $(top_srcdir)/m4/vasnprintf.m4 \
+	$(top_srcdir)/m4/vasprintf.m4 $(top_srcdir)/m4/wchar_t.m4 \
+	$(top_srcdir)/m4/wcwidth.m4 $(top_srcdir)/m4/wint_t.m4 \
+	$(top_srcdir)/m4/xalloc.m4 $(top_srcdir)/m4/xsize.m4 \
+	$(top_srcdir)/m4/xvasprintf.m4 $(top_srcdir)/acinclude.m4 \
+	$(top_srcdir)/configure.ac
+am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
+	$(ACLOCAL_M4)
+mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = config.h
+CONFIG_CLEAN_FILES =
+LIBRARIES = $(noinst_LIBRARIES)
+AR = ar
+ARFLAGS = cru
+libm4_a_AR = $(AR) $(ARFLAGS)
+am__DEPENDENCIES_1 =
+am_libm4_a_OBJECTS = allocsa.$(OBJEXT) gl_avltree_oset.$(OBJEXT) \
+	clean-temp.$(OBJEXT) fatal-signal.$(OBJEXT) \
+	gl_linkedhash_list.$(OBJEXT) gl_list.$(OBJEXT) \
+	gl_oset.$(OBJEXT) strnlen1.$(OBJEXT) tmpdir.$(OBJEXT) \
+	verror.$(OBJEXT) xalloc-die.$(OBJEXT) xallocsa.$(OBJEXT) \
+	xvasprintf.$(OBJEXT) xasprintf.$(OBJEXT)
+libm4_a_OBJECTS = $(am_libm4_a_OBJECTS)
+DEFAULT_INCLUDES = -I.@am__isrc@
+depcomp = $(SHELL) $(top_srcdir)/depcomp
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+	    echo "INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'"` install
+mostlyclean-generic:
+	-test -z "$(MOSTLYCLEANFILES)" || rm -f $(MOSTLYCLEANFILES)
+
+clean-generic:
+	-test -z "$(CLEANFILES)" || rm -f $(CLEANFILES)
+
+distclean-generic:
+	-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
+	-test -z "$(DISTCLEANFILES)" || rm -f $(DISTCLEANFILES)
+
+maintainer-clean-generic:
+	@echo "This command is intended for maintainers to use"
+	@echo "it deletes files that may require special tools to rebuild."
+	-test -z "$(BUILT_SOURCES)" || rm -f $(BUILT_SOURCES)
+	-test -z "$(MAINTAINERCLEANFILES)" || rm -f $(MAINTAINERCLEANFILES)
+clean: clean-am
+
+clean-am: clean-generic clean-noinstLIBRARIES mostlyclean-am
+
+distclean: distclean-am
+	-rm -rf $(DEPDIR) ./$(DEPDIR)
+	-rm -f Makefile
+distclean-am: clean-am distclean-compile distclean-generic \
+	distclean-hdr distclean-tags
+
+dvi: dvi-am
+
+dvi-am:
+
+html: html-am
+
+info: info-am
+
+info-am:
+
+install-data-am:
+
+install-dvi: install-dvi-am
+
+install-exec-am:
+
+install-html: install-html-am
+
+install-info: install-info-am
+
+install-man:
+
+install-pdf: install-pdf-am
+
+install-ps: install-ps-am
+
+installcheck-am:
+
+maintainer-clean: maintainer-clean-am
+	-rm -rf $(DEPDIR) ./$(DEPDIR)
+	-rm -f Makefile
+maintainer-clean-am: distclean-am maintainer-clean-generic
+
+mostlyclean: mostlyclean-am
+
+mostlyclean-am: mostlyclean-compile mostlyclean-generic \
+	mostlyclean-local
+
+pdf: pdf-am
+
+pdf-am:
+
+ps: ps-am
+
+ps-am:
+
+uninstall-am:
+
+.MAKE: install-am install-strip
+
+.PHONY: CTAGS GTAGS all all-am check check-am clean clean-generic \
+	clean-noinstLIBRARIES ctags distclean distclean-compile \
+	distclean-generic distclean-hdr distclean-tags distdir dvi \
+	dvi-am html html-am info info-am install install-am \
+	install-data install-data-am install-dvi install-dvi-am \
+	install-exec install-exec-am install-html install-html-am \
+	install-info install-info-am install-man install-pdf \
+	install-pdf-am install-ps install-ps-am install-strip \
+	installcheck installcheck-am installdirs maintainer-clean \
+	maintainer-clean-generic mostlyclean mostlyclean-compile \
+	mostlyclean-generic mostlyclean-local pdf pdf-am ps ps-am tags \
+	uninstall uninstall-am
+
+
+# We need the following in order to create <alloca.h> when the system
+# doesn't have one that works with the given compiler.
+alloca.h: alloca_.h
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  cat $(srcdir)/alloca_.h; \
+	} > $@-t
+	mv -f $@-t $@
+
+# We need the following in order to create <getopt.h> when the system
+# doesn't have one that works with the given compiler.
+getopt.h: getopt_.h
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  cat $(srcdir)/getopt_.h; \
+	} > $@-t
+	mv -f $@-t $@
+
+# We need the following in order to create <stdbool.h> when the system
+# doesn't have one that works.
+stdbool.h: stdbool_.h
+	rm -f $@-t $@
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's/@''HAVE__BOOL''@/$(HAVE__BOOL)/g' < $(srcdir)/stdbool_.h; \
+	} > $@-t
+	mv $@-t $@
+
+# We need the following in order to create <stdint.h> when the system
+# doesn't have one that works with the given compiler.
+stdint.h: stdint_.h
+	rm -f $@-t $@
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's/@''HAVE_WCHAR_H''@/$(HAVE_WCHAR_H)/g' \
+	      -e 's/@''HAVE_STDINT_H''@/$(HAVE_STDINT_H)/g' \
+	      -e 's|@''ABSOLUTE_STDINT_H''@|$(ABSOLUTE_STDINT_H)|g' \
+	      -e 's/@''HAVE_SYS_TYPES_H''@/$(HAVE_SYS_TYPES_H)/g' \
+	      -e 's/@''HAVE_INTTYPES_H''@/$(HAVE_INTTYPES_H)/g' \
+	      -e 's/@''HAVE_SYS_INTTYPES_H''@/$(HAVE_SYS_INTTYPES_H)/g' \
+	      -e 's/@''HAVE_SYS_BITYPES_H''@/$(HAVE_SYS_BITYPES_H)/g' \
+	      -e 's/@''HAVE_LONG_LONG_INT''@/$(HAVE_LONG_LONG_INT)/g' \
+	      -e 's/@''HAVE_UNSIGNED_LONG_LONG_INT''@/$(HAVE_UNSIGNED_LONG_LONG_INT)/g' \
+	      -e 's/@''BITSIZEOF_PTRDIFF_T''@/$(BITSIZEOF_PTRDIFF_T)/g' \
+	      -e 's/@''PTRDIFF_T_SUFFIX''@/$(PTRDIFF_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_SIG_ATOMIC_T''@/$(BITSIZEOF_SIG_ATOMIC_T)/g' \
+	      -e 's/@''HAVE_SIGNED_SIG_ATOMIC_T''@/$(HAVE_SIGNED_SIG_ATOMIC_T)/g' \
+	      -e 's/@''SIG_ATOMIC_T_SUFFIX''@/$(SIG_ATOMIC_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_SIZE_T''@/$(BITSIZEOF_SIZE_T)/g' \
+	      -e 's/@''SIZE_T_SUFFIX''@/$(SIZE_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_WCHAR_T''@/$(BITSIZEOF_WCHAR_T)/g' \
+	      -e 's/@''HAVE_SIGNED_WCHAR_T''@/$(HAVE_SIGNED_WCHAR_T)/g' \
+	      -e 's/@''WCHAR_T_SUFFIX''@/$(WCHAR_T_SUFFIX)/g' \
+	      -e 's/@''BITSIZEOF_WINT_T''@/$(BITSIZEOF_WINT_T)/g' \
+	      -e 's/@''HAVE_SIGNED_WINT_T''@/$(HAVE_SIGNED_WINT_T)/g' \
+	      -e 's/@''WINT_T_SUFFIX''@/$(WINT_T_SUFFIX)/g' \
+	      < $(srcdir)/stdint_.h; \
+	} > $@-t
+	mv $@-t $@
+
+# We need the following in order to create <sys/stat.h> when the system
+# has one that is incomplete.
+sys/stat.h: stat_.h
+	test -d sys || mkdir sys
+	rm -f $@-t $@
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's|@''ABSOLUTE_SYS_STAT_H''@|$(ABSOLUTE_SYS_STAT_H)|g' \
+	      < $(srcdir)/stat_.h; \
+	} > $@-t
+	mv $@-t $@
+
+# We need the following in order to create an empty placeholder for
+# <unistd.h> when the system doesn't have one.
+unistd.h:
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  echo '/* Empty placeholder for $@.  */'; \
+	} > $@
+
+mostlyclean-local: mostlyclean-generic
+	@for dir in '' $(MOSTLYCLEANDIRS); do \
+	  if test -n "$$dir" && test -d $$dir; then \
+	    echo "rmdir $$dir"; rmdir $$dir; \
+	  fi; \
+	done
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/src/bin/m4/lib/__fpending.c b/src/bin/m4/lib/__fpending.c
new file mode 100644
index 0000000000..221aee69de
--- /dev/null
+++ b/src/bin/m4/lib/__fpending.c
@@ -0,0 +1,30 @@
+/* __fpending.c -- return the number of pending output bytes on a stream
+   Copyright (C) 2000, 2004, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Jim Meyering. */
+
+#include <config.h>
+
+#include "__fpending.h"
+
+/* Return the number of pending (aka buffered, unflushed)
+   bytes on the stream, FP, that is open for writing.  */
+size_t
+__fpending (FILE *fp)
+{
+  return PENDING_OUTPUT_N_BYTES;
+}
diff --git a/src/bin/m4/lib/__fpending.h b/src/bin/m4/lib/__fpending.h
new file mode 100644
index 0000000000..8a8aabcc22
--- /dev/null
+++ b/src/bin/m4/lib/__fpending.h
@@ -0,0 +1,34 @@
+/* Declare __fpending.
+
+   Copyright (C) 2000, 2003, 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+   Written by Jim Meyering.  */
+
+#include <stddef.h>
+#include <stdio.h>
+
+#ifndef HAVE_DECL___FPENDING
+"this configure-time declaration test was not run"
+#endif
+
+#if HAVE_DECL___FPENDING
+# if HAVE_STDIO_EXT_H
+#  include <stdio_ext.h>
+# endif
+#else
+size_t __fpending (FILE *);
+#endif
diff --git a/src/bin/m4/lib/alloca.c b/src/bin/m4/lib/alloca.c
new file mode 100644
index 0000000000..3a1f4e273a
--- /dev/null
+++ b/src/bin/m4/lib/alloca.c
@@ -0,0 +1,489 @@
+/* alloca.c -- allocate automatically reclaimed memory
+   (Mostly) portable public-domain implementation -- D A Gwyn
+
+   This implementation of the PWB library alloca function,
+   which is used to allocate space off the run-time stack so
+   that it is automatically reclaimed upon procedure exit,
+   was inspired by discussions with J. Q. Johnson of Cornell.
+   J.Otto Tennant <jot@cray.com> contributed the Cray support.
+
+   There are some preprocessor constants that can
+   be defined when compiling for your specific system, for
+   improved efficiency; however, the defaults should be okay.
+
+   The general concept of this implementation is to keep
+   track of all alloca-allocated blocks, and reclaim any
+   that are found to be deeper in the stack than the current
+   invocation.  This heuristic does not reclaim storage as
+   soon as it becomes invalid, but it will do so eventually.
+
+   As a special case, alloca(0) reclaims storage without
+   allocating any.  It is a good idea to use alloca(0) in
+   your main control loop, etc. to force garbage collection.  */
+
+#include <config.h>
+
+#include <alloca.h>
+
+#include <string.h>
+#include <stdlib.h>
+
+#ifdef emacs
+# include "lisp.h"
+# include "blockinput.h"
+# ifdef EMACS_FREE
+#  undef free
+#  define free EMACS_FREE
+# endif
+#else
+# define memory_full() abort ()
+#endif
+
+/* If compiling with GCC 2, this file's not needed.  */
+#if !defined (__GNUC__) || __GNUC__ < 2
+
+/* If someone has defined alloca as a macro,
+   there must be some other way alloca is supposed to work.  */
+# ifndef alloca
+
+#  ifdef emacs
+#   ifdef static
+/* actually, only want this if static is defined as ""
+   -- this is for usg, in which emacs must undefine static
+   in order to make unexec workable
+   */
+#    ifndef STACK_DIRECTION
+you
+lose
+-- must know STACK_DIRECTION at compile-time
+/* Using #error here is not wise since this file should work for
+   old and obscure compilers.  */
+#    endif /* STACK_DIRECTION undefined */
+#   endif /* static */
+#  endif /* emacs */
+
+/* If your stack is a linked list of frames, you have to
+   provide an "address metric" ADDRESS_FUNCTION macro.  */
+
+#  if defined (CRAY) && defined (CRAY_STACKSEG_END)
+long i00afunc ();
+#   define ADDRESS_FUNCTION(arg) (char *) i00afunc (&(arg))
+#  else
+#   define ADDRESS_FUNCTION(arg) &(arg)
+#  endif
+
+/* Define STACK_DIRECTION if you know the direction of stack
+   growth for your system; otherwise it will be automatically
+   deduced at run-time.
+
+   STACK_DIRECTION > 0 => grows toward higher addresses
+   STACK_DIRECTION < 0 => grows toward lower addresses
+   STACK_DIRECTION = 0 => direction of growth unknown  */
+
+#  ifndef STACK_DIRECTION
+#   define STACK_DIRECTION	0	/* Direction unknown.  */
+#  endif
+
+#  if STACK_DIRECTION != 0
+
+#   define STACK_DIR	STACK_DIRECTION	/* Known at compile-time.  */
+
+#  else /* STACK_DIRECTION == 0; need run-time code.  */
+
+static int stack_dir;		/* 1 or -1 once known.  */
+#   define STACK_DIR	stack_dir
+
+static void
+find_stack_direction (void)
+{
+  static char *addr = NULL;	/* Address of first `dummy', once known.  */
+  auto char dummy;		/* To get stack address.  */
+
+  if (addr == NULL)
+    {				/* Initial entry.  */
+      addr = ADDRESS_FUNCTION (dummy);
+
+      find_stack_direction ();	/* Recurse once.  */
+    }
+  else
+    {
+      /* Second entry.  */
+      if (ADDRESS_FUNCTION (dummy) > addr)
+	stack_dir = 1;		/* Stack grew upward.  */
+      else
+	stack_dir = -1;		/* Stack grew downward.  */
+    }
+}
+
+#  endif /* STACK_DIRECTION == 0 */
+
+/* An "alloca header" is used to:
+   (a) chain together all alloca'ed blocks;
+   (b) keep track of stack depth.
+
+   It is very important that sizeof(header) agree with malloc
+   alignment chunk size.  The following default should work okay.  */
+
+#  ifndef	ALIGN_SIZE
+#   define ALIGN_SIZE	sizeof(double)
+#  endif
+
+typedef union hdr
+{
+  char align[ALIGN_SIZE];	/* To force sizeof(header).  */
+  struct
+    {
+      union hdr *next;		/* For chaining headers.  */
+      char *deep;		/* For stack depth measure.  */
+    } h;
+} header;
+
+static header *last_alloca_header = NULL;	/* -> last alloca header.  */
+
+/* Return a pointer to at least SIZE bytes of storage,
+   which will be automatically reclaimed upon exit from
+   the procedure that called alloca.  Originally, this space
+   was supposed to be taken from the current stack frame of the
+   caller, but that method cannot be made to work for some
+   implementations of C, for example under Gould's UTX/32.  */
+
+void *
+alloca (size_t size)
+{
+  auto char probe;		/* Probes stack depth: */
+  register char *depth = ADDRESS_FUNCTION (probe);
+
+#  if STACK_DIRECTION == 0
+  if (STACK_DIR == 0)		/* Unknown growth direction.  */
+    find_stack_direction ();
+#  endif
+
+  /* Reclaim garbage, defined as all alloca'd storage that
+     was allocated from deeper in the stack than currently.  */
+
+  {
+    register header *hp;	/* Traverses linked list.  */
+
+#  ifdef emacs
+    BLOCK_INPUT;
+#  endif
+
+    for (hp = last_alloca_header; hp != NULL;)
+      if ((STACK_DIR > 0 && hp->h.deep > depth)
+	  || (STACK_DIR < 0 && hp->h.deep < depth))
+	{
+	  register header *np = hp->h.next;
+
+	  free (hp);		/* Collect garbage.  */
+
+	  hp = np;		/* -> next header.  */
+	}
+      else
+	break;			/* Rest are not deeper.  */
+
+    last_alloca_header = hp;	/* -> last valid storage.  */
+
+#  ifdef emacs
+    UNBLOCK_INPUT;
+#  endif
+  }
+
+  if (size == 0)
+    return NULL;		/* No allocation required.  */
+
+  /* Allocate combined header + user data storage.  */
+
+  {
+    /* Address of header.  */
+    register header *new;
+
+    size_t combined_size = sizeof (header) + size;
+    if (combined_size < sizeof (header))
+      memory_full ();
+
+    new = malloc (combined_size);
+
+    if (! new)
+      memory_full ();
+
+    new->h.next = last_alloca_header;
+    new->h.deep = depth;
+
+    last_alloca_header = new;
+
+    /* User storage begins just after header.  */
+
+    return (void *) (new + 1);
+  }
+}
+
+#  if defined (CRAY) && defined (CRAY_STACKSEG_END)
+
+#   ifdef DEBUG_I00AFUNC
+#    include <stdio.h>
+#   endif
+
+#   ifndef CRAY_STACK
+#    define CRAY_STACK
+#    ifndef CRAY2
+/* Stack structures for CRAY-1, CRAY X-MP, and CRAY Y-MP */
+struct stack_control_header
+  {
+    long shgrow:32;		/* Number of times stack has grown.  */
+    long shaseg:32;		/* Size of increments to stack.  */
+    long shhwm:32;		/* High water mark of stack.  */
+    long shsize:32;		/* Current size of stack (all segments).  */
+  };
+
+/* The stack segment linkage control information occurs at
+   the high-address end of a stack segment.  (The stack
+   grows from low addresses to high addresses.)  The initial
+   part of the stack segment linkage control information is
+   0200 (octal) words.  This provides for register storage
+   for the routine which overflows the stack.  */
+
+struct stack_segment_linkage
+  {
+    long ss[0200];		/* 0200 overflow words.  */
+    long sssize:32;		/* Number of words in this segment.  */
+    long ssbase:32;		/* Offset to stack base.  */
+    long:32;
+    long sspseg:32;		/* Offset to linkage control of previous
+				   segment of stack.  */
+    long:32;
+    long sstcpt:32;		/* Pointer to task common address block.  */
+    long sscsnm;		/* Private control structure number for
+				   microtasking.  */
+    long ssusr1;		/* Reserved for user.  */
+    long ssusr2;		/* Reserved for user.  */
+    long sstpid;		/* Process ID for pid based multi-tasking.  */
+    long ssgvup;		/* Pointer to multitasking thread giveup.  */
+    long sscray[7];		/* Reserved for Cray Research.  */
+    long ssa0;
+    long ssa1;
+    long ssa2;
+    long ssa3;
+    long ssa4;
+    long ssa5;
+    long ssa6;
+    long ssa7;
+    long sss0;
+    long sss1;
+    long sss2;
+    long sss3;
+    long sss4;
+    long sss5;
+    long sss6;
+    long sss7;
+  };
+
+#    else /* CRAY2 */
+/* The following structure defines the vector of words
+   returned by the STKSTAT library routine.  */
+struct stk_stat
+  {
+    long now;			/* Current total stack size.  */
+    long maxc;			/* Amount of contiguous space which would
+				   be required to satisfy the maximum
+				   stack demand to date.  */
+    long high_water;		/* Stack high-water mark.  */
+    long overflows;		/* Number of stack overflow ($STKOFEN) calls.  */
+    long hits;			/* Number of internal buffer hits.  */
+    long extends;		/* Number of block extensions.  */
+    long stko_mallocs;		/* Block allocations by $STKOFEN.  */
+    long underflows;		/* Number of stack underflow calls ($STKRETN).  */
+    long stko_free;		/* Number of deallocations by $STKRETN.  */
+    long stkm_free;		/* Number of deallocations by $STKMRET.  */
+    long segments;		/* Current number of stack segments.  */
+    long maxs;			/* Maximum number of stack segments so far.  */
+    long pad_size;		/* Stack pad size.  */
+    long current_address;	/* Current stack segment address.  */
+    long current_size;		/* Current stack segment size.  This
+				   number is actually corrupted by STKSTAT to
+				   include the fifteen word trailer area.  */
+    long initial_address;	/* Address of initial segment.  */
+    long initial_size;		/* Size of initial segment.  */
+  };
+
+/* The following structure describes the data structure which trails
+   any stack segment.  I think that the description in 'asdef' is
+   out of date.  I only describe the parts that I am sure about.  */
+
+struct stk_trailer
+  {
+    long this_address;		/* Address of this block.  */
+    long this_size;		/* Size of this block (does not include
+				   this trailer).  */
+    long unknown2;
+    long unknown3;
+    long link;			/* Address of trailer block of previous
+				   segment.  */
+    long unknown5;
+    long unknown6;
+    long unknown7;
+    long unknown8;
+    long unknown9;
+    long unknown10;
+    long unknown11;
+    long unknown12;
+    long unknown13;
+    long unknown14;
+  };
+
+#    endif /* CRAY2 */
+#   endif /* not CRAY_STACK */
+
+#   ifdef CRAY2
+/* Determine a "stack measure" for an arbitrary ADDRESS.
+   I doubt that "lint" will like this much.  */
+
+static long
+i00afunc (long *address)
+{
+  struct stk_stat status;
+  struct stk_trailer *trailer;
+  long *block, size;
+  long result = 0;
+
+  /* We want to iterate through all of the segments.  The first
+     step is to get the stack status structure.  We could do this
+     more quickly and more directly, perhaps, by referencing the
+     $LM00 common block, but I know that this works.  */
+
+  STKSTAT (&status);
+
+  /* Set up the iteration.  */
+
+  trailer = (struct stk_trailer *) (status.current_address
+				    + status.current_size
+				    - 15);
+
+  /* There must be at least one stack segment.  Therefore it is
+     a fatal error if "trailer" is null.  */
+
+  if (trailer == 0)
+    abort ();
+
+  /* Discard segments that do not contain our argument address.  */
+
+  while (trailer != 0)
+    {
+      block = (long *) trailer->this_address;
+      size = trailer->this_size;
+      if (block == 0 || size == 0)
+	abort ();
+      trailer = (struct stk_trailer *) trailer->link;
+      if ((block <= address) && (address < (block + size)))
+	break;
+    }
+
+  /* Set the result to the offset in this segment and add the sizes
+     of all predecessor segments.  */
+
+  result = address - block;
+
+  if (trailer == 0)
+    {
+      return result;
+    }
+
+  do
+    {
+      if (trailer->this_size <= 0)
+	abort ();
+      result += trailer->this_size;
+      trailer = (struct stk_trailer *) trailer->link;
+    }
+  while (trailer != 0);
+
+  /* We are done.  Note that if you present a bogus address (one
+     not in any segment), you will get a different number back, formed
+     from subtracting the address of the first block.  This is probably
+     not what you want.  */
+
+  return (result);
+}
+
+#   else /* not CRAY2 */
+/* Stack address function for a CRAY-1, CRAY X-MP, or CRAY Y-MP.
+   Determine the number of the cell within the stack,
+   given the address of the cell.  The purpose of this
+   routine is to linearize, in some sense, stack addresses
+   for alloca.  */
+
+static long
+i00afunc (long address)
+{
+  long stkl = 0;
+
+  long size, pseg, this_segment, stack;
+  long result = 0;
+
+  struct stack_segment_linkage *ssptr;
+
+  /* Register B67 contains the address of the end of the
+     current stack segment.  If you (as a subprogram) store
+     your registers on the stack and find that you are past
+     the contents of B67, you have overflowed the segment.
+
+     B67 also points to the stack segment linkage control
+     area, which is what we are really interested in.  */
+
+  stkl = CRAY_STACKSEG_END ();
+  ssptr = (struct stack_segment_linkage *) stkl;
+
+  /* If one subtracts 'size' from the end of the segment,
+     one has the address of the first word of the segment.
+
+     If this is not the first segment, 'pseg' will be
+     nonzero.  */
+
+  pseg = ssptr->sspseg;
+  size = ssptr->sssize;
+
+  this_segment = stkl - size;
+
+  /* It is possible that calling this routine itself caused
+     a stack overflow.  Discard stack segments which do not
+     contain the target address.  */
+
+  while (!(this_segment <= address && address <= stkl))
+    {
+#    ifdef DEBUG_I00AFUNC
+      fprintf (stderr, "%011o %011o %011o\n", this_segment, address, stkl);
+#    endif
+      if (pseg == 0)
+	break;
+      stkl = stkl - pseg;
+      ssptr = (struct stack_segment_linkage *) stkl;
+      size = ssptr->sssize;
+      pseg = ssptr->sspseg;
+      this_segment = stkl - size;
+    }
+
+  result = address - this_segment;
+
+  /* If you subtract pseg from the current end of the stack,
+     you get the address of the previous stack segment's end.
+     This seems a little convoluted to me, but I'll bet you save
+     a cycle somewhere.  */
+
+  while (pseg != 0)
+    {
+#    ifdef DEBUG_I00AFUNC
+      fprintf (stderr, "%011o %011o\n", pseg, size);
+#    endif
+      stkl = stkl - pseg;
+      ssptr = (struct stack_segment_linkage *) stkl;
+      size = ssptr->sssize;
+      pseg = ssptr->sspseg;
+      result += size;
+    }
+  return (result);
+}
+
+#   endif /* not CRAY2 */
+#  endif /* CRAY */
+
+# endif /* no alloca */
+#endif /* not GCC version 2 */
diff --git a/src/bin/m4/lib/alloca_.h b/src/bin/m4/lib/alloca_.h
new file mode 100644
index 0000000000..dd0b3e98f5
--- /dev/null
+++ b/src/bin/m4/lib/alloca_.h
@@ -0,0 +1,54 @@
+/* Memory allocation on the stack.
+
+   Copyright (C) 1995, 1999, 2001, 2002, 2003, 2004, 2006 Free Software
+   Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+   USA.  */
+
+/* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H
+   means there is a real alloca function.  */
+#ifndef _GNULIB_ALLOCA_H
+# define _GNULIB_ALLOCA_H
+
+/* alloca (N) returns a pointer to N bytes of memory
+   allocated on the stack, which will last until the function returns.
+   Use of alloca should be avoided:
+     - inside arguments of function calls - undefined behaviour,
+     - in inline functions - the allocation may actually last until the
+       calling function returns,
+     - for huge N (say, N >= 65536) - you never know how large (or small)
+       the stack is, and when the stack cannot fulfill the memory allocation
+       request, the program just crashes.
+ */
+
+#ifndef alloca
+# ifdef __GNUC__
+#  define alloca __builtin_alloca
+# elif defined _AIX
+#  define alloca __alloca
+# elif defined _MSC_VER
+#  include <malloc.h>
+#  define alloca _alloca
+# else
+#  include <stddef.h>
+#  ifdef  __cplusplus
+extern "C"
+#  endif
+void *alloca (size_t);
+# endif
+#endif
+
+#endif /* _GNULIB_ALLOCA_H */
diff --git a/src/bin/m4/lib/allocsa.c b/src/bin/m4/lib/allocsa.c
new file mode 100644
index 0000000000..97652e6889
--- /dev/null
+++ b/src/bin/m4/lib/allocsa.c
@@ -0,0 +1,137 @@
+/* Safe automatic memory allocation.
+   Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "allocsa.h"
+
+/* The speed critical point in this file is freesa() applied to an alloca()
+   result: it must be fast, to match the speed of alloca().  The speed of
+   mallocsa() and freesa() in the other case are not critical, because they
+   are only invoked for big memory sizes.  */
+
+#if HAVE_ALLOCA
+
+/* Store the mallocsa() results in a hash table.  This is needed to reliably
+   distinguish a mallocsa() result and an alloca() result.
+
+   Although it is possible that the same pointer is returned by alloca() and
+   by mallocsa() at different times in the same application, it does not lead
+   to a bug in freesa(), because:
+     - Before a pointer returned by alloca() can point into malloc()ed memory,
+       the function must return, and once this has happened the programmer must
+       not call freesa() on it anyway.
+     - Before a pointer returned by mallocsa() can point into the stack, it
+       must be freed.  The only function that can free it is freesa(), and
+       when freesa() frees it, it also removes it from the hash table.  */
+
+#define MAGIC_NUMBER 0x1415fb4a
+#define MAGIC_SIZE sizeof (int)
+/* This is how the header info would look like without any alignment
+   considerations.  */
+struct preliminary_header { void *next; char room[MAGIC_SIZE]; };
+/* But the header's size must be a multiple of sa_alignment_max.  */
+#define HEADER_SIZE \
+  (((sizeof (struct preliminary_header) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max)
+struct header { void *next; char room[HEADER_SIZE - sizeof (struct preliminary_header) + MAGIC_SIZE]; };
+/* Verify that HEADER_SIZE == sizeof (struct header).  */
+typedef int verify1[2 * (HEADER_SIZE == sizeof (struct header)) - 1];
+/* We make the hash table quite big, so that during lookups the probability
+   of empty hash buckets is quite high.  There is no need to make the hash
+   table resizable, because when the hash table gets filled so much that the
+   lookup becomes slow, it means that the application has memory leaks.  */
+#define HASH_TABLE_SIZE 257
+static void * mallocsa_results[HASH_TABLE_SIZE];
+
+#endif
+
+void *
+mallocsa (size_t n)
+{
+#if HAVE_ALLOCA
+  /* Allocate one more word, that serves as an indicator for malloc()ed
+     memory, so that freesa() of an alloca() result is fast.  */
+  size_t nplus = n + HEADER_SIZE;
+
+  if (nplus >= n)
+    {
+      char *p = (char *) malloc (nplus);
+
+      if (p != NULL)
+	{
+	  size_t slot;
+
+	  p += HEADER_SIZE;
+
+	  /* Put a magic number into the indicator word.  */
+	  ((int *) p)[-1] = MAGIC_NUMBER;
+
+	  /* Enter p into the hash table.  */
+	  slot = (unsigned long) p % HASH_TABLE_SIZE;
+	  ((struct header *) (p - HEADER_SIZE))->next = mallocsa_results[slot];
+	  mallocsa_results[slot] = p;
+
+	  return p;
+	}
+    }
+  /* Out of memory.  */
+  return NULL;
+#else
+# if !MALLOC_0_IS_NONNULL
+  if (n == 0)
+    n = 1;
+# endif
+  return malloc (n);
+#endif
+}
+
+#if HAVE_ALLOCA
+void
+freesa (void *p)
+{
+  /* mallocsa() may have returned NULL.  */
+  if (p != NULL)
+    {
+      /* Attempt to quickly distinguish the mallocsa() result - which has
+	 a magic indicator word - and the alloca() result - which has an
+	 uninitialized indicator word.  It is for this test that sa_increment
+	 additional bytes are allocated in the alloca() case.  */
+      if (((int *) p)[-1] == MAGIC_NUMBER)
+	{
+	  /* Looks like a mallocsa() result.  To see whether it really is one,
+	     perform a lookup in the hash table.  */
+	  size_t slot = (unsigned long) p % HASH_TABLE_SIZE;
+	  void **chain = &mallocsa_results[slot];
+	  for (; *chain != NULL;)
+	    {
+	      if (*chain == p)
+		{
+		  /* Found it.  Remove it from the hash table and free it.  */
+		  char *p_begin = (char *) p - HEADER_SIZE;
+		  *chain = ((struct header *) p_begin)->next;
+		  free (p_begin);
+		  return;
+		}
+	      chain = &((struct header *) ((char *) *chain - HEADER_SIZE))->next;
+	    }
+	}
+      /* At this point, we know it was not a mallocsa() result.  */
+    }
+}
+#endif
diff --git a/src/bin/m4/lib/allocsa.h b/src/bin/m4/lib/allocsa.h
new file mode 100644
index 0000000000..0fd46a8e6a
--- /dev/null
+++ b/src/bin/m4/lib/allocsa.h
@@ -0,0 +1,128 @@
+/* Safe automatic memory allocation.
+   Copyright (C) 2003-2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _ALLOCSA_H
+#define _ALLOCSA_H
+
+#include <alloca.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* safe_alloca(N) is equivalent to alloca(N) when it is safe to call
+   alloca(N); otherwise it returns NULL.  It either returns N bytes of
+   memory allocated on the stack, that lasts until the function returns,
+   or NULL.
+   Use of safe_alloca should be avoided:
+     - inside arguments of function calls - undefined behaviour,
+     - in inline functions - the allocation may actually last until the
+       calling function returns.
+*/
+#if HAVE_ALLOCA
+/* The OS usually guarantees only one guard page at the bottom of the stack,
+   and a page size can be as small as 4096 bytes.  So we cannot safely
+   allocate anything larger than 4096 bytes.  Also care for the possibility
+   of a few compiler-allocated temporary stack slots.
+   This must be a macro, not an inline function.  */
+# define safe_alloca(N) ((N) < 4032 ? alloca (N) : NULL)
+#else
+# define safe_alloca(N) ((N), NULL)
+#endif
+
+/* allocsa(N) is a safe variant of alloca(N).  It allocates N bytes of
+   memory allocated on the stack, that must be freed using freesa() before
+   the function returns.  Upon failure, it returns NULL.  */
+#if HAVE_ALLOCA
+# define allocsa(N) \
+  ((N) < 4032 - sa_increment					    \
+   ? (void *) ((char *) alloca ((N) + sa_increment) + sa_increment) \
+   : mallocsa (N))
+#else
+# define allocsa(N) \
+  mallocsa (N)
+#endif
+extern void * mallocsa (size_t n);
+
+/* Free a block of memory allocated through allocsa().  */
+#if HAVE_ALLOCA
+extern void freesa (void *p);
+#else
+# define freesa free
+#endif
+
+/* Maybe we should also define a variant
+    nallocsa (size_t n, size_t s) - behaves like allocsa (n * s)
+   If this would be useful in your application. please speak up.  */
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+/* ------------------- Auxiliary, non-public definitions ------------------- */
+
+/* Determine the alignment of a type at compile time.  */
+#if defined __GNUC__
+# define sa_alignof __alignof__
+#elif defined __cplusplus
+  template <class type> struct sa_alignof_helper { char __slot1; type __slot2; };
+# define sa_alignof(type) offsetof (sa_alignof_helper<type>, __slot2)
+#elif defined __hpux
+  /* Work around a HP-UX 10.20 cc bug with enums constants defined as offsetof
+     values.  */
+# define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8)
+#elif defined _AIX
+  /* Work around an AIX 3.2.5 xlc bug with enums constants defined as offsetof
+     values.  */
+# define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8)
+#else
+# define sa_alignof(type) offsetof (struct { char __slot1; type __slot2; }, __slot2)
+#endif
+
+enum
+{
+/* The desired alignment of memory allocations is the maximum alignment
+   among all elementary types.  */
+  sa_alignment_long = sa_alignof (long),
+  sa_alignment_double = sa_alignof (double),
+#ifdef HAVE_LONG_LONG_INT
+  sa_alignment_longlong = sa_alignof (long long),
+#endif
+#ifdef HAVE_LONG_DOUBLE
+  sa_alignment_longdouble = sa_alignof (long double),
+#endif
+  sa_alignment_max = ((sa_alignment_long - 1) | (sa_alignment_double - 1)
+#ifdef HAVE_LONG_LONG_INT
+		      | (sa_alignment_longlong - 1)
+#endif
+#ifdef HAVE_LONG_DOUBLE
+		      | (sa_alignment_longdouble - 1)
+#endif
+		     ) + 1,
+/* The increment that guarantees room for a magic word must be >= sizeof (int)
+   and a multiple of sa_alignment_max.  */
+  sa_increment = ((sizeof (int) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max
+};
+
+#endif /* _ALLOCSA_H */
diff --git a/src/bin/m4/lib/allocsa.valgrind b/src/bin/m4/lib/allocsa.valgrind
new file mode 100644
index 0000000000..f4c77d6861
--- /dev/null
+++ b/src/bin/m4/lib/allocsa.valgrind
@@ -0,0 +1,7 @@
+# Suppress a valgrind message about use of uninitialized memory in freesa().
+# This use is OK because it provides only a speedup.
+{
+    freesa
+    Memcheck:Cond
+    fun:freesa
+}
diff --git a/src/bin/m4/lib/asnprintf.c b/src/bin/m4/lib/asnprintf.c
new file mode 100644
index 0000000000..26c3988b01
--- /dev/null
+++ b/src/bin/m4/lib/asnprintf.c
@@ -0,0 +1,35 @@
+/* Formatted output to strings.
+   Copyright (C) 1999, 2002, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "vasnprintf.h"
+
+#include <stdarg.h>
+
+char *
+asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...)
+{
+  va_list args;
+  char *result;
+
+  va_start (args, format);
+  result = vasnprintf (resultbuf, lengthp, format, args);
+  va_end (args);
+  return result;
+}
diff --git a/src/bin/m4/lib/asprintf.c b/src/bin/m4/lib/asprintf.c
new file mode 100644
index 0000000000..29ac6cf2d1
--- /dev/null
+++ b/src/bin/m4/lib/asprintf.c
@@ -0,0 +1,35 @@
+/* Formatted output to strings.
+   Copyright (C) 1999, 2002, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "vasprintf.h"
+
+#include <stdarg.h>
+
+int
+asprintf (char **resultp, const char *format, ...)
+{
+  va_list args;
+  int result;
+
+  va_start (args, format);
+  result = vasprintf (resultp, format, args);
+  va_end (args);
+  return result;
+}
diff --git a/src/bin/m4/lib/binary-io.h b/src/bin/m4/lib/binary-io.h
new file mode 100644
index 0000000000..d9748ee252
--- /dev/null
+++ b/src/bin/m4/lib/binary-io.h
@@ -0,0 +1,64 @@
+/* Binary mode I/O.
+   Copyright (C) 2001, 2003, 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _BINARY_H
+#define _BINARY_H
+
+/* For systems that distinguish between text and binary I/O.
+   O_BINARY is usually declared in <fcntl.h>. */
+#include <fcntl.h>
+
+/* The MSVC7 <stdio.h> doesn't like to be included after '#define fileno ...',
+   so we include it here first.  */
+#include <stdio.h>
+
+#if !defined O_BINARY && defined _O_BINARY
+  /* For MSC-compatible compilers.  */
+# define O_BINARY _O_BINARY
+# define O_TEXT _O_TEXT
+#endif
+#ifdef __BEOS__
+  /* BeOS 5 has O_BINARY and O_TEXT, but they have no effect.  */
+# undef O_BINARY
+# undef O_TEXT
+#endif
+#if O_BINARY
+# if !(defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__)
+#  define setmode _setmode
+#  undef fileno
+#  define fileno _fileno
+# endif
+# if defined __DJGPP__ || defined __CYGWIN__
+#  include <io.h> /* declares setmode() */
+# endif
+# ifdef __DJGPP__
+#  include <unistd.h> /* declares isatty() */
+#  /* Avoid putting stdin/stdout in binary mode if it is connected to the
+#     console, because that would make it impossible for the user to
+#     interrupt the program through Ctrl-C or Ctrl-Break.  */
+#  define SET_BINARY(fd) (!isatty (fd) ? (setmode (fd, O_BINARY), 0) : 0)
+# else
+#  define SET_BINARY(fd) setmode (fd, O_BINARY)
+# endif
+#else
+  /* On reasonable systems, binary I/O is the default.  */
+# undef O_BINARY
+# define O_BINARY 0
+# define SET_BINARY(fd) /* nothing */
+#endif
+
+#endif /* _BINARY_H */
diff --git a/src/bin/m4/lib/clean-temp.c b/src/bin/m4/lib/clean-temp.c
new file mode 100644
index 0000000000..aa82974a1e
--- /dev/null
+++ b/src/bin/m4/lib/clean-temp.c
@@ -0,0 +1,715 @@
+/* Temporary directories and temporary files with automatic cleanup.
+   Copyright (C) 2001, 2003, 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+
+#include <config.h>
+
+/* Specification.  */
+#include "clean-temp.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "error.h"
+#include "fatal-signal.h"
+#include "pathmax.h"
+#include "tmpdir.h"
+#include "mkdtemp.h"
+#include "xalloc.h"
+#include "xallocsa.h"
+#include "gl_linkedhash_list.h"
+#include "gettext.h"
+#if GNULIB_FWRITEERROR
+# include "fwriteerror.h"
+#endif
+#if GNULIB_CLOSE_STREAM
+# include "close-stream.h"
+#endif
+#if GNULIB_FCNTL_SAFER
+# include "fcntl--.h"
+#endif
+#if GNULIB_FOPEN_SAFER
+# include "stdio--.h"
+#endif
+
+#define _(str) gettext (str)
+
+/* GNU Hurd doesn't have PATH_MAX.  */
+#ifndef PATH_MAX
+# ifdef MAXPATHLEN
+#  define PATH_MAX MAXPATHLEN
+# else
+#  define PATH_MAX 1024
+# endif
+#endif
+
+#ifndef uintptr_t
+# define uintptr_t unsigned long
+#endif
+
+
+/* The use of 'volatile' in the types below (and ISO C 99 section 5.1.2.3.(5))
+   ensure that while constructing or modifying the data structures, the field
+   values are written to memory in the order of the C statements.  So the
+   signal handler can rely on these field values to be up to date.  */
+
+
+/* Registry for a single temporary directory.
+   'struct temp_dir' from the public header file overlaps with this.  */
+struct tempdir
+{
+  /* The absolute pathname of the directory.  */
+  char * volatile dirname;
+  /* Whether errors during explicit cleanup are reported to standard error.  */
+  bool cleanup_verbose;
+  /* Absolute pathnames of subdirectories.  */
+  gl_list_t /* <char *> */ volatile subdirs;
+  /* Absolute pathnames of files.  */
+  gl_list_t /* <char *> */ volatile files;
+};
+
+/* List of all temporary directories.  */
+static struct
+{
+  struct tempdir * volatile * volatile tempdir_list;
+  size_t volatile tempdir_count;
+  size_t tempdir_allocated;
+} cleanup_list /* = { NULL, 0, 0 } */;
+
+/* List of all open file descriptors to temporary files.  */
+static gl_list_t /* <int> */ volatile descriptors;
+
+
+/* For the subdirs and for the files, we use a gl_list_t of type LINKEDHASH.
+   Why?  We need a data structure that
+
+     1) Can contain an arbitrary number of 'char *' values.  The strings
+        are compared via strcmp, not pointer comparison.
+     2) Has insertion and deletion operations that are fast: ideally O(1),
+        or possibly O(log n).  This is important for GNU sort, which may
+        create a large number of temporary files.
+     3) Allows iteration through all elements from within a signal handler.
+     4) May or may not allow duplicates.  It doesn't matter here, since
+        any file or subdir can only be removed once.
+
+   Criterion 1) would allow any gl_list_t or gl_oset_t implementation.
+
+   Criterion 2) leaves only GL_LINKEDHASH_LIST, GL_TREEHASH_LIST, or
+   GL_TREE_OSET.
+
+   Criterion 3) puts at disadvantage GL_TREEHASH_LIST and GL_TREE_OSET.
+   Namely, iteration through the elements of a binary tree requires access
+   to many ->left, ->right, ->parent pointers. However, the rebalancing
+   code for insertion and deletion in an AVL or red-black tree is so
+   complicated that we cannot assume that >left, ->right, ->parent pointers
+   are in a consistent state throughout these operations.  Therefore, to
+   avoid a crash in the signal handler, all destructive operations to the
+   lists would have to be protected by a
+       block_fatal_signals ();
+       ...
+       unblock_fatal_signals ();
+   pair.  Which causes extra system calls.
+
+   Criterion 3) would also discourage GL_ARRAY_LIST and GL_CARRAY_LIST,
+   if they were not already excluded.  Namely, these implementations use
+   xrealloc(), leaving a time window in which in the list->elements pointer
+   points to already deallocated memory.  To avoid a crash in the signal
+   handler at such a moment, all destructive operations would have to
+   protected by block/unblock_fatal_signals (), in this case too.
+
+   A list of type GL_LINKEDHASH_LIST without duplicates fulfills all
+   requirements:
+     2) Insertion and deletion are O(1) on average.
+     3) The gl_list_iterator, gl_list_iterator_next implementations do
+        not trigger memory allocations, nor other system calls, and are
+        therefore safe to be called from a signal handler.
+        Furthermore, since SIGNAL_SAFE_LIST is defined, the implementation
+        of the destructive functions ensures that the list structure is
+        safe to be traversed at any moment, even when interrupted by an
+        asynchronous signal.
+ */
+
+/* String equality and hash code functions used by the lists.  */
+
+static bool
+string_equals (const void *x1, const void *x2)
+{
+  const char *s1 = (const char *) x1;
+  const char *s2 = (const char *) x2;
+  return strcmp (s1, s2) == 0;
+}
+
+#define SIZE_BITS (sizeof (size_t) * CHAR_BIT)
+
+/* A hash function for NUL-terminated char* strings using
+   the method described by Bruno Haible.
+   See http://www.haible.de/bruno/hashfunc.html.  */
+static size_t
+string_hash (const void *x)
+{
+  const char *s = (const char *) x;
+  size_t h = 0;
+
+  for (; *s; s++)
+    h = *s + ((h << 9) | (h >> (SIZE_BITS - 9)));
+
+  return h;
+}
+
+
+/* The signal handler.  It gets called asynchronously.  */
+static void
+cleanup ()
+{
+  size_t i;
+
+  /* First close all file descriptors to temporary files.  */
+  {
+    gl_list_t fds = descriptors;
+
+    if (fds != NULL)
+      {
+	gl_list_iterator_t iter;
+	const void *element;
+
+	iter = gl_list_iterator (fds);
+	while (gl_list_iterator_next (&iter, &element, NULL))
+	  {
+	    int fd = (int) (uintptr_t) element;
+	    close (fd);
+	  }
+	gl_list_iterator_free (&iter);
+      }
+  }
+
+  for (i = 0; i < cleanup_list.tempdir_count; i++)
+    {
+      struct tempdir *dir = cleanup_list.tempdir_list[i];
+
+      if (dir != NULL)
+	{
+	  gl_list_iterator_t iter;
+	  const void *element;
+
+	  /* First cleanup the files in the subdirectories.  */
+	  iter = gl_list_iterator (dir->files);
+	  while (gl_list_iterator_next (&iter, &element, NULL))
+	    {
+	      const char *file = (const char *) element;
+	      unlink (file);
+	    }
+	  gl_list_iterator_free (&iter);
+
+	  /* Then cleanup the subdirectories.  */
+	  iter = gl_list_iterator (dir->subdirs);
+	  while (gl_list_iterator_next (&iter, &element, NULL))
+	    {
+	      const char *subdir = (const char *) element;
+	      rmdir (subdir);
+	    }
+	  gl_list_iterator_free (&iter);
+
+	  /* Then cleanup the temporary directory itself.  */
+	  rmdir (dir->dirname);
+	}
+    }
+}
+
+/* Create a temporary directory.
+   PREFIX is used as a prefix for the name of the temporary directory. It
+   should be short and still give an indication about the program.
+   PARENTDIR can be used to specify the parent directory; if NULL, a default
+   parent directory is used (either $TMPDIR or /tmp or similar).
+   CLEANUP_VERBOSE determines whether errors during explicit cleanup are
+   reported to standard error.
+   Return a fresh 'struct temp_dir' on success.  Upon error, an error message
+   is shown and NULL is returned.  */
+struct temp_dir *
+create_temp_dir (const char *prefix, const char *parentdir,
+		 bool cleanup_verbose)
+{
+  struct tempdir * volatile *tmpdirp = NULL;
+  struct tempdir *tmpdir;
+  size_t i;
+  char *xtemplate;
+  char *tmpdirname;
+
+  /* See whether it can take the slot of an earlier temporary directory
+     already cleaned up.  */
+  for (i = 0; i < cleanup_list.tempdir_count; i++)
+    if (cleanup_list.tempdir_list[i] == NULL)
+      {
+	tmpdirp = &cleanup_list.tempdir_list[i];
+	break;
+      }
+  if (tmpdirp == NULL)
+    {
+      /* See whether the array needs to be extended.  */
+      if (cleanup_list.tempdir_count == cleanup_list.tempdir_allocated)
+	{
+	  /* Note that we cannot use xrealloc(), because then the cleanup()
+	     function could access an already deallocated array.  */
+	  struct tempdir * volatile *old_array = cleanup_list.tempdir_list;
+	  size_t old_allocated = cleanup_list.tempdir_allocated;
+	  size_t new_allocated = 2 * cleanup_list.tempdir_allocated + 1;
+	  struct tempdir * volatile *new_array =
+	    XNMALLOC (new_allocated, struct tempdir * volatile);
+
+	  if (old_allocated == 0)
+	    /* First use of this facility.  Register the cleanup handler.  */
+	    at_fatal_signal (&cleanup);
+	  else
+	    {
+	      /* Don't use memcpy() here, because memcpy takes non-volatile
+		 arguments and is therefore not guaranteed to complete all
+		 memory stores before the next statement.  */
+	      size_t k;
+
+	      for (k = 0; k < old_allocated; k++)
+		new_array[k] = old_array[k];
+	    }
+
+	  cleanup_list.tempdir_list = new_array;
+	  cleanup_list.tempdir_allocated = new_allocated;
+
+	  /* Now we can free the old array.  */
+	  if (old_array != NULL)
+	    free ((struct tempdir **) old_array);
+	}
+
+      tmpdirp = &cleanup_list.tempdir_list[cleanup_list.tempdir_count];
+      /* Initialize *tmpdirp before incrementing tempdir_count, so that
+	 cleanup() will skip this entry before it is fully initialized.  */
+      *tmpdirp = NULL;
+      cleanup_list.tempdir_count++;
+    }
+
+  /* Initialize a 'struct tempdir'.  */
+  tmpdir = XMALLOC (struct tempdir);
+  tmpdir->dirname = NULL;
+  tmpdir->cleanup_verbose = cleanup_verbose;
+  tmpdir->subdirs = gl_list_create_empty (GL_LINKEDHASH_LIST,
+					  string_equals, string_hash, false);
+  tmpdir->files = gl_list_create_empty (GL_LINKEDHASH_LIST,
+					string_equals, string_hash, false);
+
+  /* Create the temporary directory.  */
+  xtemplate = (char *) xallocsa (PATH_MAX);
+  if (path_search (xtemplate, PATH_MAX, parentdir, prefix, parentdir == NULL))
+    {
+      error (0, errno,
+	     _("cannot find a temporary directory, try setting $TMPDIR"));
+      goto quit;
+    }
+  block_fatal_signals ();
+  tmpdirname = mkdtemp (xtemplate);
+  if (tmpdirname != NULL)
+    {
+      tmpdir->dirname = tmpdirname;
+      *tmpdirp = tmpdir;
+    }
+  unblock_fatal_signals ();
+  if (tmpdirname == NULL)
+    {
+      error (0, errno,
+	     _("cannot create a temporary directory using template \"%s\""),
+	     xtemplate);
+      goto quit;
+    }
+  /* Replace tmpdir->dirname with a copy that has indefinite extent.
+     We cannot do this inside the block_fatal_signals/unblock_fatal_signals
+     block because then the cleanup handler would not remove the directory
+     if xstrdup fails.  */
+  tmpdir->dirname = xstrdup (tmpdirname);
+  freesa (xtemplate);
+  return (struct temp_dir *) tmpdir;
+
+ quit:
+  freesa (xtemplate);
+  return NULL;
+}
+
+/* Register the given ABSOLUTE_FILE_NAME as being a file inside DIR, that
+   needs to be removed before DIR can be removed.
+   Should be called before the file ABSOLUTE_FILE_NAME is created.  */
+void
+register_temp_file (struct temp_dir *dir,
+		    const char *absolute_file_name)
+{
+  struct tempdir *tmpdir = (struct tempdir *)dir;
+
+  /* Add absolute_file_name to tmpdir->files, without duplicates.  */
+  if (gl_list_search (tmpdir->files, absolute_file_name) == NULL)
+    gl_list_add_first (tmpdir->files, xstrdup (absolute_file_name));
+}
+
+/* Unregister the given ABSOLUTE_FILE_NAME as being a file inside DIR, that
+   needs to be removed before DIR can be removed.
+   Should be called when the file ABSOLUTE_FILE_NAME could not be created.  */
+void
+unregister_temp_file (struct temp_dir *dir,
+		      const char *absolute_file_name)
+{
+  struct tempdir *tmpdir = (struct tempdir *)dir;
+  gl_list_t list = tmpdir->files;
+  gl_list_node_t node;
+
+  node = gl_list_search (list, absolute_file_name);
+  if (node != NULL)
+    {
+      char *old_string = (char *) gl_list_node_value (list, node);
+
+      gl_list_remove_node (list, node);
+      free (old_string);
+    }
+}
+
+/* Register the given ABSOLUTE_DIR_NAME as being a subdirectory inside DIR,
+   that needs to be removed before DIR can be removed.
+   Should be called before the subdirectory ABSOLUTE_DIR_NAME is created.  */
+void
+register_temp_subdir (struct temp_dir *dir,
+		      const char *absolute_dir_name)
+{
+  struct tempdir *tmpdir = (struct tempdir *)dir;
+
+  /* Add absolute_dir_name to tmpdir->subdirs, without duplicates.  */
+  if (gl_list_search (tmpdir->subdirs, absolute_dir_name) == NULL)
+    gl_list_add_first (tmpdir->subdirs, xstrdup (absolute_dir_name));
+}
+
+/* Unregister the given ABSOLUTE_DIR_NAME as being a subdirectory inside DIR,
+   that needs to be removed before DIR can be removed.
+   Should be called when the subdirectory ABSOLUTE_DIR_NAME could not be
+   created.  */
+void
+unregister_temp_subdir (struct temp_dir *dir,
+			const char *absolute_dir_name)
+{
+  struct tempdir *tmpdir = (struct tempdir *)dir;
+  gl_list_t list = tmpdir->subdirs;
+  gl_list_node_t node;
+
+  node = gl_list_search (list, absolute_dir_name);
+  if (node != NULL)
+    {
+      char *old_string = (char *) gl_list_node_value (list, node);
+
+      gl_list_remove_node (list, node);
+      free (old_string);
+    }
+}
+
+/* Remove a file, with optional error message.
+   Return 0 upon success, or -1 if there was some problem.  */
+static int
+do_unlink (struct temp_dir *dir, const char *absolute_file_name)
+{
+  if (unlink (absolute_file_name) < 0 && dir->cleanup_verbose
+      && errno != ENOENT)
+    {
+      error (0, errno, _("cannot remove temporary file %s"), absolute_file_name);
+      return -1;
+    }
+  return 0;
+}
+
+/* Remove a directory, with optional error message.
+   Return 0 upon success, or -1 if there was some problem.  */
+static int
+do_rmdir (struct temp_dir *dir, const char *absolute_dir_name)
+{
+  if (rmdir (absolute_dir_name) < 0 && dir->cleanup_verbose
+      && errno != ENOENT)
+    {
+      error (0, errno,
+	     _("cannot remove temporary directory %s"), absolute_dir_name);
+      return -1;
+    }
+  return 0;
+}
+
+/* Remove the given ABSOLUTE_FILE_NAME and unregister it.
+   Return 0 upon success, or -1 if there was some problem.  */
+int
+cleanup_temp_file (struct temp_dir *dir,
+		   const char *absolute_file_name)
+{
+  int err;
+
+  err = do_unlink (dir, absolute_file_name);
+  unregister_temp_file (dir, absolute_file_name);
+
+  return err;
+}
+
+/* Remove the given ABSOLUTE_DIR_NAME and unregister it.
+   Return 0 upon success, or -1 if there was some problem.  */
+int
+cleanup_temp_subdir (struct temp_dir *dir,
+		     const char *absolute_dir_name)
+{
+  int err;
+
+  err = do_rmdir (dir, absolute_dir_name);
+  unregister_temp_subdir (dir, absolute_dir_name);
+
+  return err;
+}
+
+/* Remove all registered files and subdirectories inside DIR.
+   Return 0 upon success, or -1 if there was some problem.  */
+int
+cleanup_temp_dir_contents (struct temp_dir *dir)
+{
+  struct tempdir *tmpdir = (struct tempdir *)dir;
+  int err = 0;
+  gl_list_t list;
+  gl_list_iterator_t iter;
+  const void *element;
+  gl_list_node_t node;
+
+  /* First cleanup the files in the subdirectories.  */
+  list = tmpdir->files;
+  iter = gl_list_iterator (list);
+  while (gl_list_iterator_next (&iter, &element, &node))
+    {
+      char *file = (char *) element;
+
+      err |= do_unlink (dir, file);
+      gl_list_remove_node (list, node);
+      /* Now only we can free file.  */
+      free (file);
+    }
+  gl_list_iterator_free (&iter);
+
+  /* Then cleanup the subdirectories.  */
+  list = tmpdir->subdirs;
+  iter = gl_list_iterator (list);
+  while (gl_list_iterator_next (&iter, &element, &node))
+    {
+      char *subdir = (char *) element;
+
+      err |= do_rmdir (dir, subdir);
+      gl_list_remove_node (list, node);
+      /* Now only we can free subdir.  */
+      free (subdir);
+    }
+  gl_list_iterator_free (&iter);
+
+  return err;
+}
+
+/* Remove all registered files and subdirectories inside DIR and DIR itself.
+   DIR cannot be used any more after this call.
+   Return 0 upon success, or -1 if there was some problem.  */
+int
+cleanup_temp_dir (struct temp_dir *dir)
+{
+  struct tempdir *tmpdir = (struct tempdir *)dir;
+  int err = 0;
+  size_t i;
+
+  err |= cleanup_temp_dir_contents (dir);
+  err |= do_rmdir (dir, tmpdir->dirname);
+
+  for (i = 0; i < cleanup_list.tempdir_count; i++)
+    if (cleanup_list.tempdir_list[i] == tmpdir)
+      {
+	/* Remove cleanup_list.tempdir_list[i].  */
+	if (i + 1 == cleanup_list.tempdir_count)
+	  {
+	    while (i > 0 && cleanup_list.tempdir_list[i - 1] == NULL)
+	      i--;
+	    cleanup_list.tempdir_count = i;
+	  }
+	else
+	  cleanup_list.tempdir_list[i] = NULL;
+	/* Now only we can free the tmpdir->dirname and tmpdir itself.  */
+	free (tmpdir->dirname);
+	free (tmpdir);
+	return err;
+      }
+
+  /* The user passed an invalid DIR argument.  */
+  abort ();
+}
+
+
+/* Register a file descriptor to be closed.  */
+static void
+register_fd (int fd)
+{
+  if (descriptors == NULL)
+    descriptors = gl_list_create_empty (GL_LINKEDHASH_LIST, NULL, NULL, false);
+  gl_list_add_first (descriptors, (void *) (uintptr_t) fd);
+}
+
+/* Unregister a file descriptor to be closed.  */
+static void
+unregister_fd (int fd)
+{
+  gl_list_t fds = descriptors;
+  gl_list_node_t node;
+
+  if (fds == NULL)
+    /* descriptors should already contain fd.  */
+    abort ();
+  node = gl_list_search (fds, (void *) (uintptr_t) fd);
+  if (node == NULL)
+    /* descriptors should already contain fd.  */
+    abort ();
+  gl_list_remove_node (fds, node);
+}
+
+/* Open a temporary file in a temporary directory.
+   Registers the resulting file descriptor to be closed.  */
+int
+open_temp (const char *file_name, int flags, mode_t mode)
+{
+  int fd;
+  int saved_errno;
+
+  block_fatal_signals ();
+  fd = open (file_name, flags, mode); /* actually open or open_safer */
+  saved_errno = errno;
+  if (fd >= 0)
+    register_fd (fd);
+  unblock_fatal_signals ();
+  errno = saved_errno;
+  return fd;
+}
+
+/* Open a temporary file in a temporary directory.
+   Registers the resulting file descriptor to be closed.  */
+FILE *
+fopen_temp (const char *file_name, const char *mode)
+{
+  FILE *fp;
+  int saved_errno;
+
+  block_fatal_signals ();
+  fp = fopen (file_name, mode); /* actually fopen or fopen_safer */
+  saved_errno = errno;
+  if (fp != NULL)
+    {
+      /* It is sufficient to register fileno (fp) instead of the entire fp,
+	 because at cleanup time there is no need to do an fflush (fp); a
+	 close (fileno (fp)) will be enough.  */
+      int fd = fileno (fp);
+      if (!(fd >= 0))
+	abort ();
+      register_fd (fd);
+    }
+  unblock_fatal_signals ();
+  errno = saved_errno;
+  return fp;
+}
+
+/* Close a temporary file in a temporary directory.
+   Unregisters the previously registered file descriptor.  */
+int
+close_temp (int fd)
+{
+  if (fd >= 0)
+    {
+      /* No blocking of signals is needed here, since a double close of a
+	 file descriptor is harmless.  */
+      int result = close (fd);
+      int saved_errno = errno;
+
+      /* No race condition here: we assume a single-threaded program, hence
+	 fd cannot be re-opened here.  */
+
+      unregister_fd (fd);
+
+      errno = saved_errno;
+      return result;
+    }
+  else
+    return close (fd);
+}
+
+/* Close a temporary file in a temporary directory.
+   Unregisters the previously registered file descriptor.  */
+int
+fclose_temp (FILE *fp)
+{
+  int fd = fileno (fp);
+  /* No blocking of signals is needed here, since a double close of a
+     file descriptor is harmless.  */
+  int result = fclose (fp);
+  int saved_errno = errno;
+
+  /* No race condition here: we assume a single-threaded program, hence
+     fd cannot be re-opened here.  */
+
+  unregister_fd (fd);
+
+  errno = saved_errno;
+  return result;
+}
+
+#if GNULIB_FWRITEERROR
+/* Like fwriteerror.
+   Unregisters the previously registered file descriptor.  */
+int
+fwriteerror_temp (FILE *fp)
+{
+  int fd = fileno (fp);
+  /* No blocking of signals is needed here, since a double close of a
+     file descriptor is harmless.  */
+  int result = fwriteerror (fp);
+  int saved_errno = errno;
+
+  /* No race condition here: we assume a single-threaded program, hence
+     fd cannot be re-opened here.  */
+
+  unregister_fd (fd);
+
+  errno = saved_errno;
+  return result;
+}
+#endif
+
+#if GNULIB_CLOSE_STREAM
+/* Like close_stream.
+   Unregisters the previously registered file descriptor.  */
+int
+close_stream_temp (FILE *fp)
+{
+  int fd = fileno (fp);
+  /* No blocking of signals is needed here, since a double close of a
+     file descriptor is harmless.  */
+  int result = close_stream (fp);
+  int saved_errno = errno;
+
+  /* No race condition here: we assume a single-threaded program, hence
+     fd cannot be re-opened here.  */
+
+  unregister_fd (fd);
+
+  errno = saved_errno;
+  return result;
+}
+#endif
diff --git a/src/bin/m4/lib/clean-temp.h b/src/bin/m4/lib/clean-temp.h
new file mode 100644
index 0000000000..6e7c3e6c91
--- /dev/null
+++ b/src/bin/m4/lib/clean-temp.h
@@ -0,0 +1,134 @@
+/* Temporary directories and temporary files with automatic cleanup.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _CLEAN_TEMP_H
+#define _CLEAN_TEMP_H
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Temporary directories and temporary files should be automatically removed
+   when the program exits either normally or through a fatal signal.  We can't
+   rely on the "unlink before close" idiom, because it works only on Unix and
+   also - if no signal blocking is used - leaves a time window where a fatal
+   signal would not clean up the temporary file.
+
+   Also, open file descriptors need to be closed before the temporary files
+   and the temporary directories can be removed, because only on Unix
+   (excluding Cygwin) can one remove directories containing open files.
+
+   This module provides support for temporary directories and temporary files
+   inside these temporary directories.  Temporary files without temporary
+   directories are not supported here.  */
+
+struct temp_dir
+{
+  /* The absolute pathname of the directory.  */
+  const char * const dir_name;
+  /* Whether errors during explicit cleanup are reported to standard error.  */
+  bool cleanup_verbose;
+  /* More fields are present here, but not public.  */
+};
+
+/* Create a temporary directory.
+   PREFIX is used as a prefix for the name of the temporary directory. It
+   should be short and still give an indication about the program.
+   PARENTDIR can be used to specify the parent directory; if NULL, a default
+   parent directory is used (either $TMPDIR or /tmp or similar).
+   CLEANUP_VERBOSE determines whether errors during explicit cleanup are
+   reported to standard error.
+   Return a fresh 'struct temp_dir' on success.  Upon error, an error message
+   is shown and NULL is returned.  */
+extern struct temp_dir * create_temp_dir (const char *prefix,
+					  const char *parentdir,
+					  bool cleanup_verbose);
+
+/* Register the given ABSOLUTE_FILE_NAME as being a file inside DIR, that
+   needs to be removed before DIR can be removed.
+   Should be called before the file ABSOLUTE_FILE_NAME is created.  */
+extern void register_temp_file (struct temp_dir *dir,
+				const char *absolute_file_name);
+
+/* Unregister the given ABSOLUTE_FILE_NAME as being a file inside DIR, that
+   needs to be removed before DIR can be removed.
+   Should be called when the file ABSOLUTE_FILE_NAME could not be created.  */
+extern void unregister_temp_file (struct temp_dir *dir,
+				  const char *absolute_file_name);
+
+/* Register the given ABSOLUTE_DIR_NAME as being a subdirectory inside DIR,
+   that needs to be removed before DIR can be removed.
+   Should be called before the subdirectory ABSOLUTE_DIR_NAME is created.  */
+extern void register_temp_subdir (struct temp_dir *dir,
+				  const char *absolute_dir_name);
+
+/* Unregister the given ABSOLUTE_DIR_NAME as being a subdirectory inside DIR,
+   that needs to be removed before DIR can be removed.
+   Should be called when the subdirectory ABSOLUTE_DIR_NAME could not be
+   created.  */
+extern void unregister_temp_subdir (struct temp_dir *dir,
+				    const char *absolute_dir_name);
+
+/* Remove the given ABSOLUTE_FILE_NAME and unregister it.
+   Return 0 upon success, or -1 if there was some problem.  */
+extern int cleanup_temp_file (struct temp_dir *dir,
+			      const char *absolute_file_name);
+
+/* Remove the given ABSOLUTE_DIR_NAME and unregister it.
+   Return 0 upon success, or -1 if there was some problem.  */
+extern int cleanup_temp_subdir (struct temp_dir *dir,
+				const char *absolute_dir_name);
+
+/* Remove all registered files and subdirectories inside DIR.
+   Return 0 upon success, or -1 if there was some problem.  */
+extern int cleanup_temp_dir_contents (struct temp_dir *dir);
+
+/* Remove all registered files and subdirectories inside DIR and DIR itself.
+   DIR cannot be used any more after this call.
+   Return 0 upon success, or -1 if there was some problem.  */
+extern int cleanup_temp_dir (struct temp_dir *dir);
+
+/* Open a temporary file in a temporary directory.
+   Registers the resulting file descriptor to be closed.  */
+extern int open_temp (const char *file_name, int flags, mode_t mode);
+extern FILE * fopen_temp (const char *file_name, const char *mode);
+
+/* Close a temporary file in a temporary directory.
+   Unregisters the previously registered file descriptor.  */
+extern int close_temp (int fd);
+extern int fclose_temp (FILE *fp);
+
+/* Like fwriteerror.
+   Unregisters the previously registered file descriptor.  */
+extern int fwriteerror_temp (FILE *fp);
+
+/* Like close_stream.
+   Unregisters the previously registered file descriptor.  */
+extern int close_stream_temp (FILE *fp);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _CLEAN_TEMP_H */
diff --git a/src/bin/m4/lib/cloexec.c b/src/bin/m4/lib/cloexec.c
new file mode 100644
index 0000000000..6480006a5b
--- /dev/null
+++ b/src/bin/m4/lib/cloexec.c
@@ -0,0 +1,59 @@
+/* closexec.c - set or clear the close-on-exec descriptor flag
+
+   Copyright (C) 1991, 2004, 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+   The code is taken from glibc/manual/llio.texi  */
+
+#include <config.h>
+
+#include "cloexec.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+
+#ifndef FD_CLOEXEC
+# define FD_CLOEXEC 1
+#endif
+
+/* Set the `FD_CLOEXEC' flag of DESC if VALUE is true,
+   or clear the flag if VALUE is false.
+   Return 0 on success, or -1 on error with `errno' set. */
+
+int
+set_cloexec_flag (int desc, bool value)
+{
+#if defined F_GETFD && defined F_SETFD
+
+  int flags = fcntl (desc, F_GETFD, 0);
+
+  if (0 <= flags)
+    {
+      int newflags = (value ? flags | FD_CLOEXEC : flags & ~FD_CLOEXEC);
+
+      if (flags == newflags
+	  || fcntl (desc, F_SETFD, newflags) != -1)
+	return 0;
+    }
+
+  return -1;
+
+#else
+
+  return 0;
+
+#endif
+}
diff --git a/src/bin/m4/lib/cloexec.h b/src/bin/m4/lib/cloexec.h
new file mode 100644
index 0000000000..c25921d6b3
--- /dev/null
+++ b/src/bin/m4/lib/cloexec.h
@@ -0,0 +1,2 @@
+#include <stdbool.h>
+int set_cloexec_flag (int desc, bool value);
diff --git a/src/bin/m4/lib/close-stream.c b/src/bin/m4/lib/close-stream.c
new file mode 100644
index 0000000000..72d0d6816c
--- /dev/null
+++ b/src/bin/m4/lib/close-stream.c
@@ -0,0 +1,76 @@
+/* Close a stream, with nicer error checking than fclose's.
+
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#include "close-stream.h"
+
+#include <errno.h>
+#include <stdbool.h>
+
+#include "__fpending.h"
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+/* Close STREAM.  Return 0 if successful, EOF (setting errno)
+   otherwise.  A failure might set errno to 0 if the error number
+   cannot be determined.
+
+   If a program writes *anything* to STREAM, that program should close
+   STREAM and make sure that it succeeds before exiting.  Otherwise,
+   suppose that you go to the extreme of checking the return status
+   of every function that does an explicit write to STREAM.  The last
+   printf can succeed in writing to the internal stream buffer, and yet
+   the fclose(STREAM) could still fail (due e.g., to a disk full error)
+   when it tries to write out that buffered data.  Thus, you would be
+   left with an incomplete output file and the offending program would
+   exit successfully.  Even calling fflush is not always sufficient,
+   since some file systems (NFS and CODA) buffer written/flushed data
+   until an actual close call.
+
+   Besides, it's wasteful to check the return value from every call
+   that writes to STREAM -- just let the internal stream state record
+   the failure.  That's what the ferror test is checking below.  */
+
+int
+close_stream (FILE *stream)
+{
+  bool some_pending = (__fpending (stream) != 0);
+  bool prev_fail = (ferror (stream) != 0);
+  bool fclose_fail = (fclose (stream) != 0);
+
+  /* Return an error indication if there was a previous failure or if
+     fclose failed, with one exception: ignore an fclose failure if
+     there was no previous error, no data remains to be flushed, and
+     fclose failed with EBADF.  That can happen when a program like cp
+     is invoked like this `cp a b >&-' (i.e., with standard output
+     closed) and doesn't generate any output (hence no previous error
+     and nothing to be flushed).  */
+
+  if (prev_fail || (fclose_fail && (some_pending || errno != EBADF)))
+    {
+      if (! fclose_fail)
+	errno = 0;
+      return EOF;
+    }
+
+  return 0;
+}
diff --git a/src/bin/m4/lib/close-stream.h b/src/bin/m4/lib/close-stream.h
new file mode 100644
index 0000000000..be3d4196b0
--- /dev/null
+++ b/src/bin/m4/lib/close-stream.h
@@ -0,0 +1,2 @@
+#include <stdio.h>
+int close_stream (FILE *stream);
diff --git a/src/bin/m4/lib/closeout.c b/src/bin/m4/lib/closeout.c
new file mode 100644
index 0000000000..830f16f8ae
--- /dev/null
+++ b/src/bin/m4/lib/closeout.c
@@ -0,0 +1,86 @@
+/* Close standard output and standard error, exiting with a diagnostic on error.
+
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#include "closeout.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
+#include "close-stream.h"
+#include "error.h"
+#include "exitfail.h"
+#include "quotearg.h"
+
+static const char *file_name;
+
+/* Set the file name to be reported in the event an error is detected
+   by close_stdout.  */
+void
+close_stdout_set_file_name (const char *file)
+{
+  file_name = file;
+}
+
+/* Close standard output.  On error, issue a diagnostic and _exit
+   with status 'exit_failure'.
+
+   Also close standard error.  On error, _exit with status 'exit_failure'.
+
+   Since close_stdout is commonly registered via 'atexit', POSIX
+   and the C standard both say that it should not call 'exit',
+   because the behavior is undefined if 'exit' is called more than
+   once.  So it calls '_exit' instead of 'exit'.  If close_stdout
+   is registered via atexit before other functions are registered,
+   the other functions can act before this _exit is invoked.
+
+   Applications that use close_stdout should flush any streams
+   other than stdout and stderr before exiting, since the call to
+   _exit will bypass other buffer flushing.  Applications should
+   be flushing and closing other streams anyway, to check for I/O
+   errors.  Also, applications should not use tmpfile, since _exit
+   can bypass the removal of these files.
+
+   It's important to detect such failures and exit nonzero because many
+   tools (most notably `make' and other build-management systems) depend
+   on being able to detect failure in other tools via their exit status.  */
+
+void
+close_stdout (void)
+{
+  if (close_stream (stdout) != 0)
+    {
+      char const *write_error = _("write error");
+      if (file_name)
+	error (0, errno, "%s: %s", quotearg_colon (file_name),
+	       write_error);
+      else
+	error (0, errno, "%s", write_error);
+
+      _exit (exit_failure);
+    }
+
+   if (close_stream (stderr) != 0)
+     _exit (exit_failure);
+}
diff --git a/src/bin/m4/lib/closeout.h b/src/bin/m4/lib/closeout.h
new file mode 100644
index 0000000000..8bed23b5f1
--- /dev/null
+++ b/src/bin/m4/lib/closeout.h
@@ -0,0 +1,33 @@
+/* Close standard output and standard error.
+
+   Copyright (C) 1998, 2000, 2003, 2004, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef CLOSEOUT_H
+# define CLOSEOUT_H 1
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+void close_stdout_set_file_name (const char *file);
+void close_stdout (void);
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif
diff --git a/src/bin/m4/lib/config.h b/src/bin/m4/lib/config.h
new file mode 100644
index 0000000000..0c7b207796
--- /dev/null
+++ b/src/bin/m4/lib/config.h
@@ -0,0 +1,607 @@
+/* lib/config.h.  Generated from config.hin by configure.  */
+/* lib/config.hin.  Generated from configure.ac by autoheader.  */
+
+/* Define this to an absolute name of <stdint.h>. */
+#define ABSOLUTE_STDINT_H "///usr/include/stdint.h"
+
+/* Define this to an absolute name of <sys/stat.h>. */
+#define ABSOLUTE_SYS_STAT_H "///usr/include/sys/stat.h"
+
+/* Define to the number of bits in type 'ptrdiff_t'. */
+#define BITSIZEOF_PTRDIFF_T 32
+
+/* Define to the number of bits in type 'sig_atomic_t'. */
+#define BITSIZEOF_SIG_ATOMIC_T 32
+
+/* Define to the number of bits in type 'size_t'. */
+#define BITSIZEOF_SIZE_T 32
+
+/* Define to the number of bits in type 'wchar_t'. */
+#define BITSIZEOF_WCHAR_T 32
+
+/* Define to the number of bits in type 'wint_t'. */
+#define BITSIZEOF_WINT_T 32
+
+/* Define to one of `_getb67', `GETB67', `getb67' for Cray-2 and Cray-YMP
+   systems. This function is required for `alloca.c' support on those systems.
+   */
+/* #undef CRAY_STACKSEG_END */
+
+/* Define to 1 if using `alloca.c'. */
+/* #undef C_ALLOCA */
+
+/* Define to 1 if the changeword(REGEXP) functionality is wanted */
+/* #undef ENABLE_CHANGEWORD */
+
+/* Define as good substitute value for EOVERFLOW. */
+/* #undef EOVERFLOW */
+
+/* Define to 1 if the return value of system() disagrees with pclose(). */
+/* #undef FUNC_SYSTEM_BROKEN */
+
+/* Define to 1 when using the gnulib close-stream module. */
+#define GNULIB_CLOSE_STREAM 1
+
+/* Define to 1 when using the gnulib fopen-safer module. */
+#define GNULIB_FOPEN_SAFER 1
+
+/* Define to 1 if you have 'alloca' after including <alloca.h>, a header that
+   may be supplied by this distribution. */
+#define HAVE_ALLOCA 1
+
+/* Define HAVE_ALLOCA_H for backward compatibility with older code that
+   includes <alloca.h> only if HAVE_ALLOCA_H is defined. */
+#define HAVE_ALLOCA_H 1
+
+/* Define to 1 if you have the <bp-sym.h> header file. */
+/* #undef HAVE_BP_SYM_H */
+
+/* Define to 1 if you have the declaration of `clearerr_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_CLEARERR_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `feof_unlocked', and to 0 if you
+   don't. */
+#define HAVE_DECL_FEOF_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `ferror_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_FERROR_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `fflush_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_FFLUSH_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `fgets_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_FGETS_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `fputc_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_FPUTC_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `fputs_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_FPUTS_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `fread_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_FREAD_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `fwrite_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_FWRITE_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `getchar_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_GETCHAR_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `getc_unlocked', and to 0 if you
+   don't. */
+#define HAVE_DECL_GETC_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `getenv', and to 0 if you don't.
+   */
+#define HAVE_DECL_GETENV 1
+
+/* Define to 1 if you have the declaration of `isblank', and to 0 if you
+   don't. */
+/* #undef HAVE_DECL_ISBLANK */
+
+/* Define to 1 if you have the declaration of `mkdir', and to 0 if you don't.
+   */
+#define HAVE_DECL_MKDIR 1
+
+/* Define to 1 if you have the declaration of `putchar_unlocked', and to 0 if
+   you don't. */
+#define HAVE_DECL_PUTCHAR_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `putc_unlocked', and to 0 if you
+   don't. */
+#define HAVE_DECL_PUTC_UNLOCKED 1
+
+/* Define to 1 if you have the declaration of `strerror_r', and to 0 if you
+   don't. */
+#define HAVE_DECL_STRERROR_R 1
+
+/* Define to 1 if you have the declaration of `strncasecmp', and to 0 if you
+   don't. */
+#define HAVE_DECL_STRNCASECMP 1
+
+/* Define to 1 if you have the declaration of `wcwidth', and to 0 if you
+   don't. */
+#define HAVE_DECL_WCWIDTH 1
+
+/* Define to 1 if you have the declaration of `__fpending', and to 0 if you
+   don't. */
+#define HAVE_DECL___FPENDING 1
+
+/* Define to 1 if you have the <getopt.h> header file. */
+#define HAVE_GETOPT_H 1
+
+/* Define to 1 if you have the `getopt_long_only' function. */
+#define HAVE_GETOPT_LONG_ONLY 1
+
+/* Define to 1 if you have the `gettimeofday' function. */
+#define HAVE_GETTIMEOFDAY 1
+
+/* Define to 1 if the compiler supports one of the keywords 'inline',
+   '__inline__', '__inline' and effectively inlines functions marked as such.
+   */
+#define HAVE_INLINE 1
+
+/* Define if you have the 'intmax_t' type in <stdint.h> or <inttypes.h>. */
+#define HAVE_INTMAX_T 1
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#define HAVE_INTTYPES_H 1
+
+/* Define if <inttypes.h> exists, doesn't clash with <sys/types.h>, and
+   declares uintmax_t. */
+#define HAVE_INTTYPES_H_WITH_UINTMAX 1
+
+/* Define to 1 if you have the <io.h> header file. */
+/* #undef HAVE_IO_H */
+
+/* Define to 1 if you have the `iswcntrl' function. */
+#define HAVE_ISWCNTRL 1
+
+/* Define to 1 if you have the `iswprint' function. */
+#define HAVE_ISWPRINT 1
+
+/* Define if you have <langinfo.h> and nl_langinfo(CODESET). */
+#define HAVE_LANGINFO_CODESET 1
+
+/* Define to 1 if you have the <limits.h> header file. */
+#define HAVE_LIMITS_H 1
+
+/* Define to 1 if you have the <locale.h> header file. */
+#define HAVE_LOCALE_H 1
+
+/* Define if you have the 'long double' type. */
+#define HAVE_LONG_DOUBLE 1
+
+/* Define if you have the 'long long' type. */
+#define HAVE_LONG_LONG 1
+
+/* Define to 1 if the system has the type `long long int'. */
+#define HAVE_LONG_LONG_INT 1
+
+/* Define to 1 if you have the `lstat' function. */
+#define HAVE_LSTAT 1
+
+/* Define to 1 if your system has a GNU libc compatible `malloc' function, and
+   to 0 otherwise. */
+#define HAVE_MALLOC 1
+
+/* Define to 1 if you have the `mbrtowc' function. */
+#define HAVE_MBRTOWC 1
+
+/* Define to 1 if you have the `mbsinit' function. */
+#define HAVE_MBSINIT 1
+
+/* Define to 1 if <wchar.h> declares mbstate_t. */
+#define HAVE_MBSTATE_T 1
+
+/* Define to 1 if you have the `memchr' function. */
+#define HAVE_MEMCHR 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#define HAVE_MEMORY_H 1
+
+/* Define to 1 if you have the `mempcpy' function. */
+#define HAVE_MEMPCPY 1
+
+/* Define to 1 if you have the `mkdtemp' function. */
+#define HAVE_MKDTEMP 1
+
+/* Define to 1 if libc includes obstacks. */
+#define HAVE_OBSTACK 1
+
+/* Define to 1 if you have the `pipe' function. */
+#define HAVE_PIPE 1
+
+/* Define to 1 if you have the sigset_t type and the sigprocmask function. */
+#define HAVE_POSIX_SIGNALBLOCKING 1
+
+/* Define to 1 if the system has the type `ptrdiff_t'. */
+#define HAVE_PTRDIFF_T 1
+
+/* Define to 1 if you have the `raise' function. */
+#define HAVE_RAISE 1
+
+/* Define to 1 if the system has the type `rlim_t'. */
+#define HAVE_RLIM_T 1
+
+/* Define to 1 if you have the `sigaction' function. */
+#define HAVE_SIGACTION 1
+
+/* Define to 1 if you have the `sigaltstack' function. */
+// #define HAVE_SIGALTSTACK 1
+
+/* Define to 1 if the system has the type `sigcontext'. */
+/* #undef HAVE_SIGCONTEXT */
+
+/* Define to 1 if you have the <siginfo.h> header file. */
+/* #undef HAVE_SIGINFO_H */
+
+/* Define to 1 if the system has the type `siginfo_t'. */
+#define HAVE_SIGINFO_T 1
+
+/* Define to 1 if 'sig_atomic_t' is a signed integer type. */
+#define HAVE_SIGNED_SIG_ATOMIC_T 1
+
+/* Define to 1 if 'wchar_t' is a signed integer type. */
+#define HAVE_SIGNED_WCHAR_T 1
+
+/* Define to 1 if 'wint_t' is a signed integer type. */
+/* #undef HAVE_SIGNED_WINT_T */
+
+/* Define to 1 if you lack the sigprocmask function but have the sigset_t
+   type. */
+/* #undef HAVE_SIGSET_T */
+
+/* Define to 1 if you have the `sigstack' function. */
+#define HAVE_SIGSTACK 1
+
+/* Define to 1 if you have the `sigvec' function. */
+#define HAVE_SIGVEC 1
+
+/* Define to 1 if the system has the type `sig_atomic_t'. */
+#define HAVE_SIG_ATOMIC_T 1
+
+/* Define to 1 if you have the `snprintf' function. */
+#define HAVE_SNPRINTF 1
+
+/* Define to 1 if the system has the type `stack_t'. */
+#define HAVE_STACK_T 1
+
+/* Define to 1 if stdbool.h conforms to C99. */
+#define HAVE_STDBOOL_H 1
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#define HAVE_STDINT_H 1
+
+/* Define if <stdint.h> exists, doesn't clash with <sys/types.h>, and declares
+   uintmax_t. */
+#define HAVE_STDINT_H_WITH_UINTMAX 1
+
+/* Define to 1 if you have the <stdio_ext.h> header file. */
+// #define HAVE_STDIO_EXT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#define HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the `strerror' function. */
+#define HAVE_STRERROR 1
+
+/* Define to 1 if you have the `strerror_r' function. */
+#define HAVE_STRERROR_R 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#define HAVE_STRINGS_H 1
+
+/* Define to 1 if you have the <string.h> header file. */
+#define HAVE_STRING_H 1
+
+/* Define to 1 if you have the `strncasecmp' function. */
+#define HAVE_STRNCASECMP 1
+
+/* Define to 1 if you have the `strtol' function. */
+#define HAVE_STRTOL 1
+
+/* Define to 1 if `sa_sigaction' is member of `struct sigaction'. */
+// #define HAVE_STRUCT_SIGACTION_SA_SIGACTION 1
+
+/* Define to 1 if you have the <sys/bitypes.h> header file. */
+#define HAVE_SYS_BITYPES_H 1
+
+/* Define to 1 if you have the <sys/inttypes.h> header file. */
+/* #undef HAVE_SYS_INTTYPES_H */
+
+/* Define to 1 if you have the <sys/param.h> header file. */
+#define HAVE_SYS_PARAM_H 1
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#define HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/time.h> header file. */
+#define HAVE_SYS_TIME_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#define HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <sys/wait.h> header file. */
+#define HAVE_SYS_WAIT_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#define HAVE_UNISTD_H 1
+
+/* Define to 1 if the system has the type `unsigned long long int'. */
+#define HAVE_UNSIGNED_LONG_LONG_INT 1
+
+/* Define to 1 if you have the `vasnprintf' function. */
+/* #undef HAVE_VASNPRINTF */
+
+/* Define to 1 if you have the `vasprintf' function. */
+#define HAVE_VASPRINTF 1
+
+/* Define to 1 if you have the <wchar.h> header file. */
+#define HAVE_WCHAR_H 1
+
+/* Define if you have the 'wchar_t' type. */
+#define HAVE_WCHAR_T 1
+
+/* Define to 1 if you have the `wcrtomb' function. */
+#define HAVE_WCRTOMB 1
+
+/* Define to 1 if you have the `wcscoll' function. */
+#define HAVE_WCSCOLL 1
+
+/* Define to 1 if you have the `wcslen' function. */
+#define HAVE_WCSLEN 1
+
+/* Define to 1 if you have the <wctype.h> header file. */
+#define HAVE_WCTYPE_H 1
+
+/* Define to 1 if you have the `wcwidth' function. */
+#define HAVE_WCWIDTH 1
+
+/* Define if you have the 'wint_t' type. */
+#define HAVE_WINT_T 1
+
+/* Define to 1 if the system has the type `_Bool'. */
+#define HAVE__BOOL 1
+
+/* Define to 1 if you have the `__fpending' function. */
+#define HAVE___FPENDING 1
+
+/* Define to 1 if you have the `__secure_getenv' function. */
+// #define HAVE___SECURE_GETENV 1
+
+/* If malloc(0) is != NULL, define this to 1. Otherwise define this to 0. */
+#define MALLOC_0_IS_NONNULL 1
+
+/* Name of package */
+#define PACKAGE "m4"
+
+/* Define to the address where bug reports for this package should be sent. */
+#define PACKAGE_BUGREPORT "bug-m4@gnu.org"
+
+/* Define to the full name of this package. */
+#define PACKAGE_NAME "GNU M4"
+
+/* Define to the full name and version of this package. */
+#define PACKAGE_STRING "GNU M4 1.4.8"
+
+/* Define to the one symbol short name of this package. */
+#define PACKAGE_TARNAME "m4"
+
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "1.4.8"
+
+/* the number of pending output bytes on stream `fp' */
+/* #undef PENDING_OUTPUT_N_BYTES */
+#define PENDING_OUTPUT_N_BYTES fp->_IO_write_ptr - fp->_IO_write_base
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'ptrdiff_t'. */
+#define PTRDIFF_T_SUFFIX 
+
+/* Define as the return type of signal handlers (`int' or `void'). */
+#define RETSIGTYPE void
+
+/* Define if lists must be signal-safe. */
+#define SIGNAL_SAFE_LIST 1
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'sig_atomic_t'. */
+#define SIG_ATOMIC_T_SUFFIX 
+
+/* Define as the maximum value of type 'size_t', if the system doesn't define
+   it. */
+/* #undef SIZE_MAX */
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'size_t'. */
+#define SIZE_T_SUFFIX u
+
+/* If using the C implementation of alloca, define if you know the
+   direction of stack growth for your system; otherwise it will be
+   automatically deduced at runtime.
+	STACK_DIRECTION > 0 => grows toward higher addresses
+	STACK_DIRECTION < 0 => grows toward lower addresses
+	STACK_DIRECTION = 0 => direction of growth unknown */
+/* #undef STACK_DIRECTION */
+
+/* Define to 1 if the `S_IS*' macros in <sys/stat.h> do not work properly. */
+/* #undef STAT_MACROS_BROKEN */
+
+/* Define to 1 if you have the ANSI C header files. */
+#define STDC_HEADERS 1
+
+/* Define to 1 if strerror_r returns char *. */
+#define STRERROR_R_CHAR_P 1
+
+/* Define to 1 if using stack overflow detection */
+// #define USE_STACKOVF 1
+
+/* Define to 1 if you want getc etc. to use unlocked I/O if available.
+   Unlocked I/O can improve performance in unithreaded apps, but it is not
+   safe for multithreaded apps. */
+#define USE_UNLOCKED_IO 1
+
+/* Version number of package */
+#define VERSION "1.4.8"
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'wchar_t'. */
+#define WCHAR_T_SUFFIX 
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'wint_t'. */
+#define WINT_T_SUFFIX u
+
+/* Define to 1 if malloc debugging is enabled */
+/* #undef WITH_DMALLOC */
+
+/* Define to 1 if on AIX 3.
+   System headers sometimes define this.
+   We just want to avoid a redefinition error message.  */
+#ifndef _ALL_SOURCE
+/* # undef _ALL_SOURCE */
+#endif
+
+/* Number of bits in a file offset, on hosts where this is settable. */
+#define _FILE_OFFSET_BITS 64
+
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE 1
+#endif
+
+/* Define for large files, on AIX-style hosts. */
+/* #undef _LARGE_FILES */
+
+/* Define to 1 if on MINIX. */
+/* #undef _MINIX */
+
+/* Define to 2 if the system does not provide POSIX.1 features except with
+   this defined. */
+/* #undef _POSIX_1_SOURCE */
+
+/* Define to 1 if you need to in order for `stat' and other things to work. */
+/* #undef _POSIX_SOURCE */
+
+/* Define if you want regoff_t to be at least as wide POSIX requires. */
+/* #undef _REGEX_LARGE_OFFSETS */
+
+/* Enable extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# define __EXTENSIONS__ 1
+#endif
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# define _POSIX_PTHREAD_SEMANTICS 1
+#endif
+#ifndef _TANDEM_SOURCE
+# define _TANDEM_SOURCE 1
+#endif
+
+/* Define to rpl_ if the getopt replacement functions and variables should be
+   used. */
+/* #undef __GETOPT_PREFIX */
+
+/* Define to rpl_ if the mkstemp replacement function should be used. */
+/* #undef __MKSTEMP_PREFIX */
+
+/* Define to rpl_free if the replacement function should be used. */
+/* #undef free */
+
+/* A replacement for va_copy, if needed.  */
+#define gl_va_copy(a,b) ((a) = (b))
+
+/* Define to `__inline__' or `__inline' if that's what the C compiler
+   calls it, or to nothing if 'inline' is not supported under any name.  */
+#ifndef __cplusplus
+/* #undef inline */
+#endif
+
+/* Define to long or long long if <stdint.h> and <inttypes.h> don't define. */
+/* #undef intmax_t */
+
+/* Define to rpl_malloc if the replacement function should be used. */
+/* #undef malloc */
+
+/* Define to a type if <wchar.h> does not define. */
+/* #undef mbstate_t */
+
+/* Define to rpl_re_comp if the replacement should be used. */
+/* #undef re_comp */
+
+/* Define to rpl_re_compile_fastmap if the replacement should be used. */
+/* #undef re_compile_fastmap */
+
+/* Define to rpl_re_compile_pattern if the replacement should be used. */
+/* #undef re_compile_pattern */
+
+/* Define to rpl_re_exec if the replacement should be used. */
+/* #undef re_exec */
+
+/* Define to rpl_re_match if the replacement should be used. */
+/* #undef re_match */
+
+/* Define to rpl_re_match_2 if the replacement should be used. */
+/* #undef re_match_2 */
+
+/* Define to rpl_re_search if the replacement should be used. */
+/* #undef re_search */
+
+/* Define to rpl_re_search_2 if the replacement should be used. */
+/* #undef re_search_2 */
+
+/* Define to rpl_re_set_registers if the replacement should be used. */
+/* #undef re_set_registers */
+
+/* Define to rpl_re_set_syntax if the replacement should be used. */
+/* #undef re_set_syntax */
+
+/* Define to rpl_re_syntax_options if the replacement should be used. */
+/* #undef re_syntax_options */
+
+/* Define to rpl_regcomp if the replacement should be used. */
+/* #undef regcomp */
+
+/* Define to rpl_regerror if the replacement should be used. */
+/* #undef regerror */
+
+/* Define to rpl_regexec if the replacement should be used. */
+/* #undef regexec */
+
+/* Define to rpl_regfree if the replacement should be used. */
+/* #undef regfree */
+
+/* Define to equivalent of C99 restrict keyword, or to nothing if this is not
+   supported. Do not define if restrict is supported directly. */
+#define restrict __restrict
+
+/* Define to int if rlim_t is not defined in sys/resource.h */
+/* #undef rlim_t */
+
+/* Define as an integer type suitable for memory locations that can be
+   accessed atomically even in the presence of asynchnonous signals. */
+/* #undef sig_atomic_t */
+
+/* Define to `unsigned int' if <sys/types.h> does not define. */
+/* #undef size_t */
+
+/* Define as a signed type of the same size as size_t. */
+/* #undef ssize_t */
+
+/* Define to struct sigaltstack if stack_t is not in signal.h */
+/* #undef stack_t */
+
+/* Define as a macro for copying va_list variables. */
+/* #undef va_copy */
diff --git a/src/bin/m4/lib/config.hin b/src/bin/m4/lib/config.hin
new file mode 100644
index 0000000000..fef9579162
--- /dev/null
+++ b/src/bin/m4/lib/config.hin
@@ -0,0 +1,602 @@
+/* lib/config.hin.  Generated from configure.ac by autoheader.  */
+
+/* Define this to an absolute name of <stdint.h>. */
+#undef ABSOLUTE_STDINT_H
+
+/* Define this to an absolute name of <sys/stat.h>. */
+#undef ABSOLUTE_SYS_STAT_H
+
+/* Define to the number of bits in type 'ptrdiff_t'. */
+#undef BITSIZEOF_PTRDIFF_T
+
+/* Define to the number of bits in type 'sig_atomic_t'. */
+#undef BITSIZEOF_SIG_ATOMIC_T
+
+/* Define to the number of bits in type 'size_t'. */
+#undef BITSIZEOF_SIZE_T
+
+/* Define to the number of bits in type 'wchar_t'. */
+#undef BITSIZEOF_WCHAR_T
+
+/* Define to the number of bits in type 'wint_t'. */
+#undef BITSIZEOF_WINT_T
+
+/* Define to one of `_getb67', `GETB67', `getb67' for Cray-2 and Cray-YMP
+   systems. This function is required for `alloca.c' support on those systems.
+   */
+#undef CRAY_STACKSEG_END
+
+/* Define to 1 if using `alloca.c'. */
+#undef C_ALLOCA
+
+/* Define to 1 if the changeword(REGEXP) functionality is wanted */
+#undef ENABLE_CHANGEWORD
+
+/* Define as good substitute value for EOVERFLOW. */
+#undef EOVERFLOW
+
+/* Define to 1 if the return value of system() disagrees with pclose(). */
+#undef FUNC_SYSTEM_BROKEN
+
+/* Define to 1 when using the gnulib close-stream module. */
+#undef GNULIB_CLOSE_STREAM
+
+/* Define to 1 when using the gnulib fopen-safer module. */
+#undef GNULIB_FOPEN_SAFER
+
+/* Define to 1 if you have 'alloca' after including <alloca.h>, a header that
+   may be supplied by this distribution. */
+#undef HAVE_ALLOCA
+
+/* Define HAVE_ALLOCA_H for backward compatibility with older code that
+   includes <alloca.h> only if HAVE_ALLOCA_H is defined. */
+#undef HAVE_ALLOCA_H
+
+/* Define to 1 if you have the <bp-sym.h> header file. */
+#undef HAVE_BP_SYM_H
+
+/* Define to 1 if you have the declaration of `clearerr_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_CLEARERR_UNLOCKED
+
+/* Define to 1 if you have the declaration of `feof_unlocked', and to 0 if you
+   don't. */
+#undef HAVE_DECL_FEOF_UNLOCKED
+
+/* Define to 1 if you have the declaration of `ferror_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FERROR_UNLOCKED
+
+/* Define to 1 if you have the declaration of `fflush_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FFLUSH_UNLOCKED
+
+/* Define to 1 if you have the declaration of `fgets_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FGETS_UNLOCKED
+
+/* Define to 1 if you have the declaration of `fputc_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FPUTC_UNLOCKED
+
+/* Define to 1 if you have the declaration of `fputs_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FPUTS_UNLOCKED
+
+/* Define to 1 if you have the declaration of `fread_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FREAD_UNLOCKED
+
+/* Define to 1 if you have the declaration of `fwrite_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FWRITE_UNLOCKED
+
+/* Define to 1 if you have the declaration of `getchar_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_GETCHAR_UNLOCKED
+
+/* Define to 1 if you have the declaration of `getc_unlocked', and to 0 if you
+   don't. */
+#undef HAVE_DECL_GETC_UNLOCKED
+
+/* Define to 1 if you have the declaration of `getenv', and to 0 if you don't.
+   */
+#undef HAVE_DECL_GETENV
+
+/* Define to 1 if you have the declaration of `isblank', and to 0 if you
+   don't. */
+#undef HAVE_DECL_ISBLANK
+
+/* Define to 1 if you have the declaration of `mkdir', and to 0 if you don't.
+   */
+#undef HAVE_DECL_MKDIR
+
+/* Define to 1 if you have the declaration of `putchar_unlocked', and to 0 if
+   you don't. */
+#undef HAVE_DECL_PUTCHAR_UNLOCKED
+
+/* Define to 1 if you have the declaration of `putc_unlocked', and to 0 if you
+   don't. */
+#undef HAVE_DECL_PUTC_UNLOCKED
+
+/* Define to 1 if you have the declaration of `strerror_r', and to 0 if you
+   don't. */
+#undef HAVE_DECL_STRERROR_R
+
+/* Define to 1 if you have the declaration of `strncasecmp', and to 0 if you
+   don't. */
+#undef HAVE_DECL_STRNCASECMP
+
+/* Define to 1 if you have the declaration of `wcwidth', and to 0 if you
+   don't. */
+#undef HAVE_DECL_WCWIDTH
+
+/* Define to 1 if you have the declaration of `__fpending', and to 0 if you
+   don't. */
+#undef HAVE_DECL___FPENDING
+
+/* Define to 1 if you have the <getopt.h> header file. */
+#undef HAVE_GETOPT_H
+
+/* Define to 1 if you have the `getopt_long_only' function. */
+#undef HAVE_GETOPT_LONG_ONLY
+
+/* Define to 1 if you have the `gettimeofday' function. */
+#undef HAVE_GETTIMEOFDAY
+
+/* Define to 1 if the compiler supports one of the keywords 'inline',
+   '__inline__', '__inline' and effectively inlines functions marked as such.
+   */
+#undef HAVE_INLINE
+
+/* Define if you have the 'intmax_t' type in <stdint.h> or <inttypes.h>. */
+#undef HAVE_INTMAX_T
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#undef HAVE_INTTYPES_H
+
+/* Define if <inttypes.h> exists, doesn't clash with <sys/types.h>, and
+   declares uintmax_t. */
+#undef HAVE_INTTYPES_H_WITH_UINTMAX
+
+/* Define to 1 if you have the <io.h> header file. */
+#undef HAVE_IO_H
+
+/* Define to 1 if you have the `iswcntrl' function. */
+#undef HAVE_ISWCNTRL
+
+/* Define to 1 if you have the `iswprint' function. */
+#undef HAVE_ISWPRINT
+
+/* Define if you have <langinfo.h> and nl_langinfo(CODESET). */
+#undef HAVE_LANGINFO_CODESET
+
+/* Define to 1 if you have the <limits.h> header file. */
+#undef HAVE_LIMITS_H
+
+/* Define to 1 if you have the <locale.h> header file. */
+#undef HAVE_LOCALE_H
+
+/* Define if you have the 'long double' type. */
+#undef HAVE_LONG_DOUBLE
+
+/* Define if you have the 'long long' type. */
+#undef HAVE_LONG_LONG
+
+/* Define to 1 if the system has the type `long long int'. */
+#undef HAVE_LONG_LONG_INT
+
+/* Define to 1 if you have the `lstat' function. */
+#undef HAVE_LSTAT
+
+/* Define to 1 if your system has a GNU libc compatible `malloc' function, and
+   to 0 otherwise. */
+#undef HAVE_MALLOC
+
+/* Define to 1 if you have the `mbrtowc' function. */
+#undef HAVE_MBRTOWC
+
+/* Define to 1 if you have the `mbsinit' function. */
+#undef HAVE_MBSINIT
+
+/* Define to 1 if <wchar.h> declares mbstate_t. */
+#undef HAVE_MBSTATE_T
+
+/* Define to 1 if you have the `memchr' function. */
+#undef HAVE_MEMCHR
+
+/* Define to 1 if you have the <memory.h> header file. */
+#undef HAVE_MEMORY_H
+
+/* Define to 1 if you have the `mempcpy' function. */
+#undef HAVE_MEMPCPY
+
+/* Define to 1 if you have the `mkdtemp' function. */
+#undef HAVE_MKDTEMP
+
+/* Define to 1 if libc includes obstacks. */
+#undef HAVE_OBSTACK
+
+/* Define to 1 if you have the `pipe' function. */
+#undef HAVE_PIPE
+
+/* Define to 1 if you have the sigset_t type and the sigprocmask function. */
+#undef HAVE_POSIX_SIGNALBLOCKING
+
+/* Define to 1 if the system has the type `ptrdiff_t'. */
+#undef HAVE_PTRDIFF_T
+
+/* Define to 1 if you have the `raise' function. */
+#undef HAVE_RAISE
+
+/* Define to 1 if the system has the type `rlim_t'. */
+#undef HAVE_RLIM_T
+
+/* Define to 1 if you have the `sigaction' function. */
+#undef HAVE_SIGACTION
+
+/* Define to 1 if you have the `sigaltstack' function. */
+#undef HAVE_SIGALTSTACK
+
+/* Define to 1 if the system has the type `sigcontext'. */
+#undef HAVE_SIGCONTEXT
+
+/* Define to 1 if you have the <siginfo.h> header file. */
+#undef HAVE_SIGINFO_H
+
+/* Define to 1 if the system has the type `siginfo_t'. */
+#undef HAVE_SIGINFO_T
+
+/* Define to 1 if 'sig_atomic_t' is a signed integer type. */
+#undef HAVE_SIGNED_SIG_ATOMIC_T
+
+/* Define to 1 if 'wchar_t' is a signed integer type. */
+#undef HAVE_SIGNED_WCHAR_T
+
+/* Define to 1 if 'wint_t' is a signed integer type. */
+#undef HAVE_SIGNED_WINT_T
+
+/* Define to 1 if you lack the sigprocmask function but have the sigset_t
+   type. */
+#undef HAVE_SIGSET_T
+
+/* Define to 1 if you have the `sigstack' function. */
+#undef HAVE_SIGSTACK
+
+/* Define to 1 if you have the `sigvec' function. */
+#undef HAVE_SIGVEC
+
+/* Define to 1 if the system has the type `sig_atomic_t'. */
+#undef HAVE_SIG_ATOMIC_T
+
+/* Define to 1 if you have the `snprintf' function. */
+#undef HAVE_SNPRINTF
+
+/* Define to 1 if the system has the type `stack_t'. */
+#undef HAVE_STACK_T
+
+/* Define to 1 if stdbool.h conforms to C99. */
+#undef HAVE_STDBOOL_H
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#undef HAVE_STDINT_H
+
+/* Define if <stdint.h> exists, doesn't clash with <sys/types.h>, and declares
+   uintmax_t. */
+#undef HAVE_STDINT_H_WITH_UINTMAX
+
+/* Define to 1 if you have the <stdio_ext.h> header file. */
+#undef HAVE_STDIO_EXT_H
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#undef HAVE_STDLIB_H
+
+/* Define to 1 if you have the `strerror' function. */
+#undef HAVE_STRERROR
+
+/* Define to 1 if you have the `strerror_r' function. */
+#undef HAVE_STRERROR_R
+
+/* Define to 1 if you have the <strings.h> header file. */
+#undef HAVE_STRINGS_H
+
+/* Define to 1 if you have the <string.h> header file. */
+#undef HAVE_STRING_H
+
+/* Define to 1 if you have the `strncasecmp' function. */
+#undef HAVE_STRNCASECMP
+
+/* Define to 1 if you have the `strtol' function. */
+#undef HAVE_STRTOL
+
+/* Define to 1 if `sa_sigaction' is member of `struct sigaction'. */
+#undef HAVE_STRUCT_SIGACTION_SA_SIGACTION
+
+/* Define to 1 if you have the <sys/bitypes.h> header file. */
+#undef HAVE_SYS_BITYPES_H
+
+/* Define to 1 if you have the <sys/inttypes.h> header file. */
+#undef HAVE_SYS_INTTYPES_H
+
+/* Define to 1 if you have the <sys/param.h> header file. */
+#undef HAVE_SYS_PARAM_H
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#undef HAVE_SYS_STAT_H
+
+/* Define to 1 if you have the <sys/time.h> header file. */
+#undef HAVE_SYS_TIME_H
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#undef HAVE_SYS_TYPES_H
+
+/* Define to 1 if you have the <sys/wait.h> header file. */
+#undef HAVE_SYS_WAIT_H
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#undef HAVE_UNISTD_H
+
+/* Define to 1 if the system has the type `unsigned long long int'. */
+#undef HAVE_UNSIGNED_LONG_LONG_INT
+
+/* Define to 1 if you have the `vasnprintf' function. */
+#undef HAVE_VASNPRINTF
+
+/* Define to 1 if you have the `vasprintf' function. */
+#undef HAVE_VASPRINTF
+
+/* Define to 1 if you have the <wchar.h> header file. */
+#undef HAVE_WCHAR_H
+
+/* Define if you have the 'wchar_t' type. */
+#undef HAVE_WCHAR_T
+
+/* Define to 1 if you have the `wcrtomb' function. */
+#undef HAVE_WCRTOMB
+
+/* Define to 1 if you have the `wcscoll' function. */
+#undef HAVE_WCSCOLL
+
+/* Define to 1 if you have the `wcslen' function. */
+#undef HAVE_WCSLEN
+
+/* Define to 1 if you have the <wctype.h> header file. */
+#undef HAVE_WCTYPE_H
+
+/* Define to 1 if you have the `wcwidth' function. */
+#undef HAVE_WCWIDTH
+
+/* Define if you have the 'wint_t' type. */
+#undef HAVE_WINT_T
+
+/* Define to 1 if the system has the type `_Bool'. */
+#undef HAVE__BOOL
+
+/* Define to 1 if you have the `__fpending' function. */
+#undef HAVE___FPENDING
+
+/* Define to 1 if you have the `__secure_getenv' function. */
+#undef HAVE___SECURE_GETENV
+
+/* If malloc(0) is != NULL, define this to 1. Otherwise define this to 0. */
+#undef MALLOC_0_IS_NONNULL
+
+/* Name of package */
+#undef PACKAGE
+
+/* Define to the address where bug reports for this package should be sent. */
+#undef PACKAGE_BUGREPORT
+
+/* Define to the full name of this package. */
+#undef PACKAGE_NAME
+
+/* Define to the full name and version of this package. */
+#undef PACKAGE_STRING
+
+/* Define to the one symbol short name of this package. */
+#undef PACKAGE_TARNAME
+
+/* Define to the version of this package. */
+#undef PACKAGE_VERSION
+
+/* the number of pending output bytes on stream `fp' */
+#undef PENDING_OUTPUT_N_BYTES
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'ptrdiff_t'. */
+#undef PTRDIFF_T_SUFFIX
+
+/* Define as the return type of signal handlers (`int' or `void'). */
+#undef RETSIGTYPE
+
+/* Define if lists must be signal-safe. */
+#undef SIGNAL_SAFE_LIST
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'sig_atomic_t'. */
+#undef SIG_ATOMIC_T_SUFFIX
+
+/* Define as the maximum value of type 'size_t', if the system doesn't define
+   it. */
+#undef SIZE_MAX
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'size_t'. */
+#undef SIZE_T_SUFFIX
+
+/* If using the C implementation of alloca, define if you know the
+   direction of stack growth for your system; otherwise it will be
+   automatically deduced at runtime.
+	STACK_DIRECTION > 0 => grows toward higher addresses
+	STACK_DIRECTION < 0 => grows toward lower addresses
+	STACK_DIRECTION = 0 => direction of growth unknown */
+#undef STACK_DIRECTION
+
+/* Define to 1 if the `S_IS*' macros in <sys/stat.h> do not work properly. */
+#undef STAT_MACROS_BROKEN
+
+/* Define to 1 if you have the ANSI C header files. */
+#undef STDC_HEADERS
+
+/* Define to 1 if strerror_r returns char *. */
+#undef STRERROR_R_CHAR_P
+
+/* Define to 1 if using stack overflow detection */
+#undef USE_STACKOVF
+
+/* Define to 1 if you want getc etc. to use unlocked I/O if available.
+   Unlocked I/O can improve performance in unithreaded apps, but it is not
+   safe for multithreaded apps. */
+#undef USE_UNLOCKED_IO
+
+/* Version number of package */
+#undef VERSION
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'wchar_t'. */
+#undef WCHAR_T_SUFFIX
+
+/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
+   'wint_t'. */
+#undef WINT_T_SUFFIX
+
+/* Define to 1 if malloc debugging is enabled */
+#undef WITH_DMALLOC
+
+/* Define to 1 if on AIX 3.
+   System headers sometimes define this.
+   We just want to avoid a redefinition error message.  */
+#ifndef _ALL_SOURCE
+# undef _ALL_SOURCE
+#endif
+
+/* Number of bits in a file offset, on hosts where this is settable. */
+#undef _FILE_OFFSET_BITS
+
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
+
+/* Define for large files, on AIX-style hosts. */
+#undef _LARGE_FILES
+
+/* Define to 1 if on MINIX. */
+#undef _MINIX
+
+/* Define to 2 if the system does not provide POSIX.1 features except with
+   this defined. */
+#undef _POSIX_1_SOURCE
+
+/* Define to 1 if you need to in order for `stat' and other things to work. */
+#undef _POSIX_SOURCE
+
+/* Define if you want regoff_t to be at least as wide POSIX requires. */
+#undef _REGEX_LARGE_OFFSETS
+
+/* Enable extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# undef __EXTENSIONS__
+#endif
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# undef _POSIX_PTHREAD_SEMANTICS
+#endif
+#ifndef _TANDEM_SOURCE
+# undef _TANDEM_SOURCE
+#endif
+
+/* Define to rpl_ if the getopt replacement functions and variables should be
+   used. */
+#undef __GETOPT_PREFIX
+
+/* Define to rpl_ if the mkstemp replacement function should be used. */
+#undef __MKSTEMP_PREFIX
+
+/* Define to rpl_free if the replacement function should be used. */
+#undef free
+
+/* A replacement for va_copy, if needed.  */
+#define gl_va_copy(a,b) ((a) = (b))
+
+/* Define to `__inline__' or `__inline' if that's what the C compiler
+   calls it, or to nothing if 'inline' is not supported under any name.  */
+#ifndef __cplusplus
+#undef inline
+#endif
+
+/* Define to long or long long if <stdint.h> and <inttypes.h> don't define. */
+#undef intmax_t
+
+/* Define to rpl_malloc if the replacement function should be used. */
+#undef malloc
+
+/* Define to a type if <wchar.h> does not define. */
+#undef mbstate_t
+
+/* Define to rpl_re_comp if the replacement should be used. */
+#undef re_comp
+
+/* Define to rpl_re_compile_fastmap if the replacement should be used. */
+#undef re_compile_fastmap
+
+/* Define to rpl_re_compile_pattern if the replacement should be used. */
+#undef re_compile_pattern
+
+/* Define to rpl_re_exec if the replacement should be used. */
+#undef re_exec
+
+/* Define to rpl_re_match if the replacement should be used. */
+#undef re_match
+
+/* Define to rpl_re_match_2 if the replacement should be used. */
+#undef re_match_2
+
+/* Define to rpl_re_search if the replacement should be used. */
+#undef re_search
+
+/* Define to rpl_re_search_2 if the replacement should be used. */
+#undef re_search_2
+
+/* Define to rpl_re_set_registers if the replacement should be used. */
+#undef re_set_registers
+
+/* Define to rpl_re_set_syntax if the replacement should be used. */
+#undef re_set_syntax
+
+/* Define to rpl_re_syntax_options if the replacement should be used. */
+#undef re_syntax_options
+
+/* Define to rpl_regcomp if the replacement should be used. */
+#undef regcomp
+
+/* Define to rpl_regerror if the replacement should be used. */
+#undef regerror
+
+/* Define to rpl_regexec if the replacement should be used. */
+#undef regexec
+
+/* Define to rpl_regfree if the replacement should be used. */
+#undef regfree
+
+/* Define to equivalent of C99 restrict keyword, or to nothing if this is not
+   supported. Do not define if restrict is supported directly. */
+#undef restrict
+
+/* Define to int if rlim_t is not defined in sys/resource.h */
+#undef rlim_t
+
+/* Define as an integer type suitable for memory locations that can be
+   accessed atomically even in the presence of asynchnonous signals. */
+#undef sig_atomic_t
+
+/* Define to `unsigned int' if <sys/types.h> does not define. */
+#undef size_t
+
+/* Define as a signed type of the same size as size_t. */
+#undef ssize_t
+
+/* Define to struct sigaltstack if stack_t is not in signal.h */
+#undef stack_t
+
+/* Define as a macro for copying va_list variables. */
+#undef va_copy
diff --git a/src/bin/m4/lib/dup-safer.c b/src/bin/m4/lib/dup-safer.c
new file mode 100644
index 0000000000..d0606eeb4c
--- /dev/null
+++ b/src/bin/m4/lib/dup-safer.c
@@ -0,0 +1,45 @@
+/* Invoke dup, but avoid some glitches.
+
+   Copyright (C) 2001, 2004, 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <config.h>
+
+#include "unistd-safer.h"
+
+#include <fcntl.h>
+
+#include <unistd.h>
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+/* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or
+   STDERR_FILENO.  */
+
+int
+dup_safer (int fd)
+{
+#ifdef F_DUPFD
+  return fcntl (fd, F_DUPFD, STDERR_FILENO + 1);
+#else
+  /* fd_safer calls us back, but eventually the recursion unwinds and
+     does the right thing.  */
+  return fd_safer (dup (fd));
+#endif
+}
diff --git a/src/bin/m4/lib/error.c b/src/bin/m4/lib/error.c
new file mode 100644
index 0000000000..cf86343320
--- /dev/null
+++ b/src/bin/m4/lib/error.c
@@ -0,0 +1,338 @@
+/* Error handler for noninteractive utilities
+   Copyright (C) 1990-1998, 2000-2005, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
+
+#if !_LIBC
+# include <config.h>
+#endif
+
+#include "error.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if !_LIBC && ENABLE_NLS
+# include "gettext.h"
+#endif
+
+#ifdef _LIBC
+# include <libintl.h>
+# include <stdbool.h>
+# include <stdint.h>
+# include <wchar.h>
+# define mbsrtowcs __mbsrtowcs
+#endif
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+#ifndef _
+# define _(String) String
+#endif
+
+/* If NULL, error will flush stdout, then print on stderr the program
+   name, a colon and a space.  Otherwise, error will call this
+   function without parameters instead.  */
+void (*error_print_progname) (void);
+
+/* This variable is incremented each time `error' is called.  */
+unsigned int error_message_count;
+
+#ifdef _LIBC
+/* In the GNU C library, there is a predefined variable for this.  */
+
+# define program_name program_invocation_name
+# include <errno.h>
+# include <limits.h>
+# include <libio/libioP.h>
+
+/* In GNU libc we want do not want to use the common name `error' directly.
+   Instead make it a weak alias.  */
+extern void __error (int status, int errnum, const char *message, ...)
+     __attribute__ ((__format__ (__printf__, 3, 4)));
+extern void __error_at_line (int status, int errnum, const char *file_name,
+			     unsigned int line_number, const char *message,
+			     ...)
+     __attribute__ ((__format__ (__printf__, 5, 6)));;
+# define error __error
+# define error_at_line __error_at_line
+
+# include <libio/iolibio.h>
+# define fflush(s) INTUSE(_IO_fflush) (s)
+# undef putc
+# define putc(c, fp) INTUSE(_IO_putc) (c, fp)
+
+# include <bits/libc-lock.h>
+
+#else /* not _LIBC */
+
+# if !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P
+#  ifndef HAVE_DECL_STRERROR_R
+"this configure-time declaration test was not run"
+#  endif
+char *strerror_r ();
+# endif
+
+/* The calling program should define program_name and set it to the
+   name of the executing program.  */
+extern char *program_name;
+
+# if HAVE_STRERROR_R || defined strerror_r
+#  define __strerror_r strerror_r
+# endif	/* HAVE_STRERROR_R || defined strerror_r */
+#endif	/* not _LIBC */
+
+static void
+print_errno_message (int errnum)
+{
+  char const *s;
+
+#if defined HAVE_STRERROR_R || _LIBC
+  char errbuf[1024];
+# if STRERROR_R_CHAR_P || _LIBC
+  s = __strerror_r (errnum, errbuf, sizeof errbuf);
+# else
+  if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
+    s = errbuf;
+  else
+    s = 0;
+# endif
+#else
+  s = strerror (errnum);
+#endif
+
+#if !_LIBC
+  if (! s)
+    s = _("Unknown system error");
+#endif
+
+#if _LIBC
+  __fxprintf (NULL, ": %s", s);
+#else
+  fprintf (stderr, ": %s", s);
+#endif
+}
+
+static void
+error_tail (int status, int errnum, const char *message, va_list args)
+{
+#if _LIBC
+  if (_IO_fwide (stderr, 0) > 0)
+    {
+# define ALLOCA_LIMIT 2000
+      size_t len = strlen (message) + 1;
+      wchar_t *wmessage = NULL;
+      mbstate_t st;
+      size_t res;
+      const char *tmp;
+      bool use_malloc = false;
+
+      while (1)
+	{
+	  if (__libc_use_alloca (len * sizeof (wchar_t)))
+	    wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));
+	  else
+	    {
+	      if (!use_malloc)
+		wmessage = NULL;
+
+	      wchar_t *p = (wchar_t *) realloc (wmessage,
+						len * sizeof (wchar_t));
+	      if (p == NULL)
+		{
+		  free (wmessage);
+		  fputws_unlocked (L"out of memory\n", stderr);
+		  return;
+		}
+	      wmessage = p;
+	      use_malloc = true;
+	    }
+
+	  memset (&st, '\0', sizeof (st));
+	  tmp = message;
+
+	  res = mbsrtowcs (wmessage, &tmp, len, &st);
+	  if (res != len)
+	    break;
+
+	  if (__builtin_expect (len >= SIZE_MAX / 2, 0))
+	    {
+	      /* This really should not happen if everything is fine.  */
+	      res = (size_t) -1;
+	      break;
+	    }
+
+	  len *= 2;
+	}
+
+      if (res == (size_t) -1)
+	{
+	  /* The string cannot be converted.  */
+	  if (use_malloc)
+	    {
+	      free (wmessage);
+	      use_malloc = false;
+	    }
+	  wmessage = (wchar_t *) L"???";
+	}
+
+      __vfwprintf (stderr, wmessage, args);
+
+      if (use_malloc)
+	free (wmessage);
+    }
+  else
+#endif
+    vfprintf (stderr, message, args);
+  va_end (args);
+
+  ++error_message_count;
+  if (errnum)
+    print_errno_message (errnum);
+#if _LIBC
+  __fxprintf (NULL, "\n");
+#else
+  putc ('\n', stderr);
+#endif
+  fflush (stderr);
+  if (status)
+    exit (status);
+}
+
+
+/* Print the program name and error message MESSAGE, which is a printf-style
+   format string with optional args.
+   If ERRNUM is nonzero, print its corresponding system error message.
+   Exit with status STATUS if it is nonzero.  */
+void
+error (int status, int errnum, const char *message, ...)
+{
+  va_list args;
+
+#if defined _LIBC && defined __libc_ptf_call
+  /* We do not want this call to be cut short by a thread
+     cancellation.  Therefore disable cancellation for now.  */
+  int state = PTHREAD_CANCEL_ENABLE;
+  __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
+		   0);
+#endif
+
+  fflush (stdout);
+#ifdef _LIBC
+  _IO_flockfile (stderr);
+#endif
+  if (error_print_progname)
+    (*error_print_progname) ();
+  else
+    {
+#if _LIBC
+      __fxprintf (NULL, "%s: ", program_name);
+#else
+      fprintf (stderr, "%s: ", program_name);
+#endif
+    }
+
+  va_start (args, message);
+  error_tail (status, errnum, message, args);
+
+#ifdef _LIBC
+  _IO_funlockfile (stderr);
+# ifdef __libc_ptf_call
+  __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
+# endif
+#endif
+}
+
+/* Sometimes we want to have at most one error per line.  This
+   variable controls whether this mode is selected or not.  */
+int error_one_per_line;
+
+void
+error_at_line (int status, int errnum, const char *file_name,
+	       unsigned int line_number, const char *message, ...)
+{
+  va_list args;
+
+  if (error_one_per_line)
+    {
+      static const char *old_file_name;
+      static unsigned int old_line_number;
+
+      if (old_line_number == line_number
+	  && (file_name == old_file_name
+	      || strcmp (old_file_name, file_name) == 0))
+	/* Simply return and print nothing.  */
+	return;
+
+      old_file_name = file_name;
+      old_line_number = line_number;
+    }
+
+#if defined _LIBC && defined __libc_ptf_call
+  /* We do not want this call to be cut short by a thread
+     cancellation.  Therefore disable cancellation for now.  */
+  int state = PTHREAD_CANCEL_ENABLE;
+  __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
+		   0);
+#endif
+
+  fflush (stdout);
+#ifdef _LIBC
+  _IO_flockfile (stderr);
+#endif
+  if (error_print_progname)
+    (*error_print_progname) ();
+  else
+    {
+#if _LIBC
+      __fxprintf (NULL, "%s:", program_name);
+#else
+      fprintf (stderr, "%s:", program_name);
+#endif
+    }
+
+#if _LIBC
+  __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ",
+	      file_name, line_number);
+#else
+  fprintf (stderr, file_name != NULL ? "%s:%d: " : " ",
+	   file_name, line_number);
+#endif
+
+  va_start (args, message);
+  error_tail (status, errnum, message, args);
+
+#ifdef _LIBC
+  _IO_funlockfile (stderr);
+# ifdef __libc_ptf_call
+  __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
+# endif
+#endif
+}
+
+#ifdef _LIBC
+/* Make the weak alias.  */
+# undef error
+# undef error_at_line
+weak_alias (__error, error)
+weak_alias (__error_at_line, error_at_line)
+#endif
diff --git a/src/bin/m4/lib/error.h b/src/bin/m4/lib/error.h
new file mode 100644
index 0000000000..5a5f247658
--- /dev/null
+++ b/src/bin/m4/lib/error.h
@@ -0,0 +1,66 @@
+/* Declaration for error-reporting function
+   Copyright (C) 1995, 1996, 1997, 2003, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _ERROR_H
+#define _ERROR_H 1
+
+#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
+#  define __attribute__(Spec) /* empty */
+# endif
+/* The __-protected variants of `format' and `printf' attributes
+   are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
+#  define __format__ format
+#  define __printf__ printf
+# endif
+#endif
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* Print a message with `fprintf (stderr, FORMAT, ...)';
+   if ERRNUM is nonzero, follow it with ": " and strerror (ERRNUM).
+   If STATUS is nonzero, terminate the program with `exit (STATUS)'.  */
+
+extern void error (int __status, int __errnum, const char *__format, ...)
+     __attribute__ ((__format__ (__printf__, 3, 4)));
+
+extern void error_at_line (int __status, int __errnum, const char *__fname,
+			   unsigned int __lineno, const char *__format, ...)
+     __attribute__ ((__format__ (__printf__, 5, 6)));
+
+/* If NULL, error will flush stdout, then print on stderr the program
+   name, a colon and a space.  Otherwise, error will call this
+   function without parameters instead.  */
+extern void (*error_print_progname) (void);
+
+/* This variable is incremented each time `error' is called.  */
+extern unsigned int error_message_count;
+
+/* Sometimes we want to have at most one error per line.  This
+   variable controls whether this mode is selected or not.  */
+extern int error_one_per_line;
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* error.h */
diff --git a/src/bin/m4/lib/exit.h b/src/bin/m4/lib/exit.h
new file mode 100644
index 0000000000..e8f7738838
--- /dev/null
+++ b/src/bin/m4/lib/exit.h
@@ -0,0 +1,32 @@
+/* exit() function.
+   Copyright (C) 1995, 2001 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _EXIT_H
+#define _EXIT_H
+
+/* Get exit() declaration.  */
+#include <stdlib.h>
+
+/* Some systems do not define EXIT_*, despite otherwise supporting C89.  */
+#ifndef EXIT_SUCCESS
+# define EXIT_SUCCESS 0
+#endif
+#ifndef EXIT_FAILURE
+# define EXIT_FAILURE 1
+#endif
+
+#endif /* _EXIT_H */
diff --git a/src/bin/m4/lib/exitfail.c b/src/bin/m4/lib/exitfail.c
new file mode 100644
index 0000000000..97abc674ec
--- /dev/null
+++ b/src/bin/m4/lib/exitfail.c
@@ -0,0 +1,25 @@
+/* Failure exit status
+
+   Copyright (C) 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; see the file COPYING.
+   If not, write to the Free Software Foundation,
+   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#include "exitfail.h"
+#include "exit.h"
+
+int volatile exit_failure = EXIT_FAILURE;
diff --git a/src/bin/m4/lib/exitfail.h b/src/bin/m4/lib/exitfail.h
new file mode 100644
index 0000000000..e46cf9c166
--- /dev/null
+++ b/src/bin/m4/lib/exitfail.h
@@ -0,0 +1,20 @@
+/* Failure exit status
+
+   Copyright (C) 2002 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; see the file COPYING.
+   If not, write to the Free Software Foundation,
+   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+extern int volatile exit_failure;
diff --git a/src/bin/m4/lib/fatal-signal.c b/src/bin/m4/lib/fatal-signal.c
new file mode 100644
index 0000000000..e9c9d04850
--- /dev/null
+++ b/src/bin/m4/lib/fatal-signal.c
@@ -0,0 +1,270 @@
+/* Emergency actions in case of a fatal signal.
+   Copyright (C) 2003-2004, 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+
+#include <config.h>
+
+/* Specification.  */
+#include "fatal-signal.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+
+#include "sigprocmask.h"
+#include "xalloc.h"
+
+#define SIZEOF(a) (sizeof(a) / sizeof(a[0]))
+
+
+/* ========================================================================= */
+
+
+/* The list of fatal signals.
+   These are those signals whose default action is to terminate the process
+   without a core dump, except
+     SIGKILL - because it cannot be caught,
+     SIGALRM SIGUSR1 SIGUSR2 SIGPOLL SIGIO SIGLOST - because applications
+       often use them for their own purpose,
+     SIGPROF SIGVTALRM - because they are used for profiling,
+     SIGSTKFLT - because it is more similar to SIGFPE, SIGSEGV, SIGBUS,
+     SIGSYS - because it is more similar to SIGABRT, SIGSEGV,
+     SIGPWR - because it of too special use,
+     SIGRTMIN...SIGRTMAX - because they are reserved for application use.
+   plus
+     SIGXCPU, SIGXFSZ - because they are quite similar to SIGTERM.  */
+
+static int fatal_signals[] =
+  {
+    /* ISO C 99 signals.  */
+#ifdef SIGINT
+    SIGINT,
+#endif
+#ifdef SIGTERM
+    SIGTERM,
+#endif
+    /* POSIX:2001 signals.  */
+#ifdef SIGHUP
+    SIGHUP,
+#endif
+#ifdef SIGPIPE
+    SIGPIPE,
+#endif
+    /* BSD signals.  */
+#ifdef SIGXCPU
+    SIGXCPU,
+#endif
+#ifdef SIGXFSZ
+    SIGXFSZ,
+#endif
+    /* Woe32 signals.  */
+#ifdef SIGBREAK
+    SIGBREAK,
+#endif
+    0
+  };
+
+#define num_fatal_signals (SIZEOF (fatal_signals) - 1)
+
+/* Eliminate signals whose signal handler is SIG_IGN.  */
+
+static void
+init_fatal_signals (void)
+{
+  static bool fatal_signals_initialized = false;
+  if (!fatal_signals_initialized)
+    {
+#if HAVE_SIGACTION
+      size_t i;
+
+      for (i = 0; i < num_fatal_signals; i++)
+	{
+	  struct sigaction action;
+
+	  if (sigaction (fatal_signals[i], NULL, &action) >= 0
+	      && action.sa_handler == SIG_IGN)
+	    fatal_signals[i] = -1;
+	}
+#endif
+
+      fatal_signals_initialized = true;
+    }
+}
+
+
+/* ========================================================================= */
+
+
+typedef void (*action_t) (void);
+
+/* Type of an entry in the actions array.
+   The 'action' field is accessed from within the fatal_signal_handler(),
+   therefore we mark it as 'volatile'.  */
+typedef struct
+{
+  volatile action_t action;
+}
+actions_entry_t;
+
+/* The registered cleanup actions.  */
+static actions_entry_t static_actions[32];
+static actions_entry_t * volatile actions = static_actions;
+static sig_atomic_t volatile actions_count = 0;
+static size_t actions_allocated = SIZEOF (static_actions);
+
+
+/* Uninstall the handlers.  */
+static inline void
+uninstall_handlers ()
+{
+  size_t i;
+
+  for (i = 0; i < num_fatal_signals; i++)
+    if (fatal_signals[i] >= 0)
+      signal (fatal_signals[i], SIG_DFL);
+}
+
+
+/* The signal handler.  It gets called asynchronously.  */
+static void
+fatal_signal_handler (int sig)
+{
+  for (;;)
+    {
+      /* Get the last registered cleanup action, in a reentrant way.  */
+      action_t action;
+      size_t n = actions_count;
+      if (n == 0)
+	break;
+      n--;
+      actions_count = n;
+      action = actions[n].action;
+      /* Execute the action.  */
+      action ();
+    }
+
+  /* Now execute the signal's default action.
+     If signal() blocks the signal being delivered for the duration of the
+     signal handler's execution, the re-raised signal is delivered when this
+     handler returns; otherwise it is delivered already during raise().  */
+  uninstall_handlers ();
+#if HAVE_RAISE
+  raise (sig);
+#else
+  kill (getpid (), sig);
+#endif
+}
+
+
+/* Install the handlers.  */
+static inline void
+install_handlers ()
+{
+  size_t i;
+
+  for (i = 0; i < num_fatal_signals; i++)
+    if (fatal_signals[i] >= 0)
+      signal (fatal_signals[i], &fatal_signal_handler);
+}
+
+
+/* Register a cleanup function to be executed when a catchable fatal signal
+   occurs.  */
+void
+at_fatal_signal (action_t action)
+{
+  static bool cleanup_initialized = false;
+  if (!cleanup_initialized)
+    {
+      init_fatal_signals ();
+      install_handlers ();
+      cleanup_initialized = true;
+    }
+
+  if (actions_count == actions_allocated)
+    {
+      /* Extend the actions array.  Note that we cannot use xrealloc(),
+	 because then the cleanup() function could access an already
+	 deallocated array.  */
+      actions_entry_t *old_actions = actions;
+      size_t old_actions_allocated = actions_allocated;
+      size_t new_actions_allocated = 2 * actions_allocated;
+      actions_entry_t *new_actions =
+	XNMALLOC (new_actions_allocated, actions_entry_t);
+      size_t k;
+
+      /* Don't use memcpy() here, because memcpy takes non-volatile arguments
+	 and is therefore not guaranteed to complete all memory stores before
+	 the next statement.  */
+      for (k = 0; k < old_actions_allocated; k++)
+	new_actions[k] = old_actions[k];
+      actions = new_actions;
+      actions_allocated = new_actions_allocated;
+      /* Now we can free the old actions array.  */
+      if (old_actions != static_actions)
+	free (old_actions);
+    }
+  /* The two uses of 'volatile' in the types above (and ISO C 99 section
+     5.1.2.3.(5)) ensure that we increment the actions_count only after
+     the new action has been written to the memory location
+     actions[actions_count].  */
+  actions[actions_count].action = action;
+  actions_count++;
+}
+
+
+/* ========================================================================= */
+
+
+static sigset_t fatal_signal_set;
+
+static void
+init_fatal_signal_set ()
+{
+  static bool fatal_signal_set_initialized = false;
+  if (!fatal_signal_set_initialized)
+    {
+      size_t i;
+
+      init_fatal_signals ();
+
+      sigemptyset (&fatal_signal_set);
+      for (i = 0; i < num_fatal_signals; i++)
+	if (fatal_signals[i] >= 0)
+	  sigaddset (&fatal_signal_set, fatal_signals[i]);
+
+      fatal_signal_set_initialized = true;
+    }
+}
+
+/* Temporarily delay the catchable fatal signals.  */
+void
+block_fatal_signals ()
+{
+  init_fatal_signal_set ();
+  sigprocmask (SIG_BLOCK, &fatal_signal_set, NULL);
+}
+
+/* Stop delaying the catchable fatal signals.  */
+void
+unblock_fatal_signals ()
+{
+  init_fatal_signal_set ();
+  sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
+}
diff --git a/src/bin/m4/lib/fatal-signal.h b/src/bin/m4/lib/fatal-signal.h
new file mode 100644
index 0000000000..3e6f677a87
--- /dev/null
+++ b/src/bin/m4/lib/fatal-signal.h
@@ -0,0 +1,77 @@
+/* Emergency actions in case of a fatal signal.
+   Copyright (C) 2003-2004 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* It is often useful to do some cleanup action when a usually fatal signal
+   terminates the process, like removing a temporary file or killing a
+   subprocess that may be stuck waiting for a device, pipe or network input.
+   Such signals are SIGHUP, SIGINT, SIGPIPE, SIGTERM, and possibly others.
+   The limitation of this facility is that it cannot work for SIGKILL.
+
+   Signals with a SIG_IGN handler are considered to be non-fatal.  The
+   functions in this file assume that when a SIG_IGN handler is installed
+   for a signal, it was installed before any functions in this file were
+   called and it stays so for the whole lifetime of the process.  */
+
+/* Register a cleanup function to be executed when a catchable fatal signal
+   occurs.
+
+   Restrictions for the cleanup function:
+     - The cleanup function can do all kinds of system calls.
+     - It can also access application dependent memory locations and data
+       structures provided they are in a consistent state. One way to ensure
+       this is through block_fatal_signals()/unblock_fatal_signals(), see
+       below.  Another - more tricky - way to ensure this is the careful use
+       of 'volatile'.
+   However,
+     - malloc() and similarly complex facilities are not safe to be called
+       because they are not guaranteed to be in a consistent state.
+     - Also, the cleanup function must not block the catchable fatal signals
+       and leave them blocked upon return.
+
+   The cleanup function is executed asynchronously.  It is unspecified
+   whether during its execution the catchable fatal signals are blocked
+   or not.  */
+extern void at_fatal_signal (void (*function) (void));
+
+
+/* Sometimes it is necessary to block the usually fatal signals while the
+   data structures being accessed by the cleanup action are being built or
+   reorganized.  This is the case, for example, when a temporary file or
+   directory is created through mkstemp() or mkdtemp(), because these
+   functions create the temporary file or directory _before_ returning its
+   name to the application.  */
+
+/* Temporarily delay the catchable fatal signals.
+   The signals will be blocked (= delayed) until the next call to
+   unblock_fatal_signals().  If the signals are already blocked, a further
+   call to block_fatal_signals() has no effect.  */
+extern void block_fatal_signals (void);
+
+/* Stop delaying the catchable fatal signals.  */
+extern void unblock_fatal_signals (void);
+
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/src/bin/m4/lib/fd-safer.c b/src/bin/m4/lib/fd-safer.c
new file mode 100644
index 0000000000..256bfa4a0e
--- /dev/null
+++ b/src/bin/m4/lib/fd-safer.c
@@ -0,0 +1,57 @@
+/* Return a safer copy of a file descriptor.
+
+   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <config.h>
+
+#include "unistd-safer.h"
+
+#include <errno.h>
+
+#include <unistd.h>
+#ifndef STDIN_FILENO
+# define STDIN_FILENO 0
+#endif
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+/* Return FD, unless FD would be a copy of standard input, output, or
+   error; in that case, return a duplicate of FD, closing FD.  On
+   failure to duplicate, close FD, set errno, and return -1.  Preserve
+   errno if FD is negative, so that the caller can always inspect
+   errno when the returned value is negative.
+
+   This function is usefully wrapped around functions that return file
+   descriptors, e.g., fd_safer (open ("file", O_RDONLY)).  */
+
+int
+fd_safer (int fd)
+{
+  if (STDIN_FILENO <= fd && fd <= STDERR_FILENO)
+    {
+      int f = dup_safer (fd);
+      int e = errno;
+      close (fd);
+      errno = e;
+      fd = f;
+    }
+
+  return fd;
+}
diff --git a/src/bin/m4/lib/fopen-safer.c b/src/bin/m4/lib/fopen-safer.c
new file mode 100644
index 0000000000..3502dbaa8c
--- /dev/null
+++ b/src/bin/m4/lib/fopen-safer.c
@@ -0,0 +1,68 @@
+/* Invoke fopen, but avoid some glitches.
+
+   Copyright (C) 2001, 2004, 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <config.h>
+
+#include "stdio-safer.h"
+
+#include <errno.h>
+#include <unistd.h>
+#include "unistd-safer.h"
+
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+/* Like fopen, but do not return stdin, stdout, or stderr.  */
+
+FILE *
+fopen_safer (char const *file, char const *mode)
+{
+  FILE *fp = fopen (file, mode);
+
+  if (fp)
+    {
+      int fd = fileno (fp);
+
+      if (0 <= fd && fd <= STDERR_FILENO)
+	{
+	  int f = dup_safer (fd);
+
+	  if (f < 0)
+	    {
+	      int e = errno;
+	      fclose (fp);
+	      errno = e;
+	      return NULL;
+	    }
+
+	  if (fclose (fp) != 0
+	      || ! (fp = fdopen (f, mode)))
+	    {
+	      int e = errno;
+	      close (f);
+	      errno = e;
+	      return NULL;
+	    }
+	}
+    }
+
+  return fp;
+}
diff --git a/src/bin/m4/lib/free.c b/src/bin/m4/lib/free.c
new file mode 100644
index 0000000000..73a125a75f
--- /dev/null
+++ b/src/bin/m4/lib/free.c
@@ -0,0 +1,31 @@
+/* Work around incompatibility on older systems where free (NULL) fails.
+
+   Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* written by Paul Eggert */
+
+#include <config.h>
+#undef free
+
+#include <stdlib.h>
+
+void
+rpl_free (void *p)
+{
+  if (p)
+    free (p);
+}
diff --git a/src/bin/m4/lib/getopt.c b/src/bin/m4/lib/getopt.c
new file mode 100644
index 0000000000..3580ad825c
--- /dev/null
+++ b/src/bin/m4/lib/getopt.c
@@ -0,0 +1,1191 @@
+/* Getopt for GNU.
+   NOTE: getopt is now part of the C library, so if you don't know what
+   "Keep this file name-space clean" means, talk to drepper@gnu.org
+   before changing it!
+   Copyright (C) 1987,88,89,90,91,92,93,94,95,96,98,99,2000,2001,2002,2003,2004,2006
+	Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _LIBC
+# include <config.h>
+#endif
+
+#include "getopt.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifdef __VMS
+# include <unixlib.h>
+#endif
+
+#ifdef _LIBC
+# include <libintl.h>
+#else
+# include "gettext.h"
+# define _(msgid) gettext (msgid)
+#endif
+
+#if defined _LIBC && defined USE_IN_LIBIO
+# include <wchar.h>
+#endif
+
+#ifndef attribute_hidden
+# define attribute_hidden
+#endif
+
+/* Unlike standard Unix `getopt', functions like `getopt_long'
+   let the user intersperse the options with the other arguments.
+
+   As `getopt_long' works, it permutes the elements of ARGV so that,
+   when it is done, all the options precede everything else.  Thus
+   all application programs are extended to handle flexible argument order.
+
+   Using `getopt' or setting the environment variable POSIXLY_CORRECT
+   disables permutation.
+   Then the application's behavior is completely standard.
+
+   GNU application programs can use a third alternative mode in which
+   they can distinguish the relative order of options and other arguments.  */
+
+#include "getopt_int.h"
+
+/* For communication from `getopt' to the caller.
+   When `getopt' finds an option that takes an argument,
+   the argument value is returned here.
+   Also, when `ordering' is RETURN_IN_ORDER,
+   each non-option ARGV-element is returned here.  */
+
+char *optarg;
+
+/* Index in ARGV of the next element to be scanned.
+   This is used for communication to and from the caller
+   and for communication between successive calls to `getopt'.
+
+   On entry to `getopt', zero means this is the first call; initialize.
+
+   When `getopt' returns -1, this is the index of the first of the
+   non-option elements that the caller should itself scan.
+
+   Otherwise, `optind' communicates from one call to the next
+   how much of ARGV has been scanned so far.  */
+
+/* 1003.2 says this must be 1 before any call.  */
+int optind = 1;
+
+/* Callers store zero here to inhibit the error message
+   for unrecognized options.  */
+
+int opterr = 1;
+
+/* Set to an option character which was unrecognized.
+   This must be initialized on some systems to avoid linking in the
+   system's own getopt implementation.  */
+
+int optopt = '?';
+
+/* Keep a global copy of all internal members of getopt_data.  */
+
+static struct _getopt_data getopt_data;
+
+
+#if defined HAVE_DECL_GETENV && !HAVE_DECL_GETENV
+extern char *getenv ();
+#endif
+
+#ifdef _LIBC
+/* Stored original parameters.
+   XXX This is no good solution.  We should rather copy the args so
+   that we can compare them later.  But we must not use malloc(3).  */
+extern int __libc_argc;
+extern char **__libc_argv;
+
+/* Bash 2.0 gives us an environment variable containing flags
+   indicating ARGV elements that should not be considered arguments.  */
+
+# ifdef USE_NONOPTION_FLAGS
+/* Defined in getopt_init.c  */
+extern char *__getopt_nonoption_flags;
+# endif
+
+# ifdef USE_NONOPTION_FLAGS
+#  define SWAP_FLAGS(ch1, ch2) \
+  if (d->__nonoption_flags_len > 0)					      \
+    {									      \
+      char __tmp = __getopt_nonoption_flags[ch1];			      \
+      __getopt_nonoption_flags[ch1] = __getopt_nonoption_flags[ch2];	      \
+      __getopt_nonoption_flags[ch2] = __tmp;				      \
+    }
+# else
+#  define SWAP_FLAGS(ch1, ch2)
+# endif
+#else	/* !_LIBC */
+# define SWAP_FLAGS(ch1, ch2)
+#endif	/* _LIBC */
+
+/* Exchange two adjacent subsequences of ARGV.
+   One subsequence is elements [first_nonopt,last_nonopt)
+   which contains all the non-options that have been skipped so far.
+   The other is elements [last_nonopt,optind), which contains all
+   the options processed since those non-options were skipped.
+
+   `first_nonopt' and `last_nonopt' are relocated so that they describe
+   the new indices of the non-options in ARGV after they are moved.  */
+
+static void
+exchange (char **argv, struct _getopt_data *d)
+{
+  int bottom = d->__first_nonopt;
+  int middle = d->__last_nonopt;
+  int top = d->optind;
+  char *tem;
+
+  /* Exchange the shorter segment with the far end of the longer segment.
+     That puts the shorter segment into the right place.
+     It leaves the longer segment in the right place overall,
+     but it consists of two parts that need to be swapped next.  */
+
+#if defined _LIBC && defined USE_NONOPTION_FLAGS
+  /* First make sure the handling of the `__getopt_nonoption_flags'
+     string can work normally.  Our top argument must be in the range
+     of the string.  */
+  if (d->__nonoption_flags_len > 0 && top >= d->__nonoption_flags_max_len)
+    {
+      /* We must extend the array.  The user plays games with us and
+	 presents new arguments.  */
+      char *new_str = malloc (top + 1);
+      if (new_str == NULL)
+	d->__nonoption_flags_len = d->__nonoption_flags_max_len = 0;
+      else
+	{
+	  memset (__mempcpy (new_str, __getopt_nonoption_flags,
+			     d->__nonoption_flags_max_len),
+		  '\0', top + 1 - d->__nonoption_flags_max_len);
+	  d->__nonoption_flags_max_len = top + 1;
+	  __getopt_nonoption_flags = new_str;
+	}
+    }
+#endif
+
+  while (top > middle && middle > bottom)
+    {
+      if (top - middle > middle - bottom)
+	{
+	  /* Bottom segment is the short one.  */
+	  int len = middle - bottom;
+	  register int i;
+
+	  /* Swap it with the top part of the top segment.  */
+	  for (i = 0; i < len; i++)
+	    {
+	      tem = argv[bottom + i];
+	      argv[bottom + i] = argv[top - (middle - bottom) + i];
+	      argv[top - (middle - bottom) + i] = tem;
+	      SWAP_FLAGS (bottom + i, top - (middle - bottom) + i);
+	    }
+	  /* Exclude the moved bottom segment from further swapping.  */
+	  top -= len;
+	}
+      else
+	{
+	  /* Top segment is the short one.  */
+	  int len = top - middle;
+	  register int i;
+
+	  /* Swap it with the bottom part of the bottom segment.  */
+	  for (i = 0; i < len; i++)
+	    {
+	      tem = argv[bottom + i];
+	      argv[bottom + i] = argv[middle + i];
+	      argv[middle + i] = tem;
+	      SWAP_FLAGS (bottom + i, middle + i);
+	    }
+	  /* Exclude the moved top segment from further swapping.  */
+	  bottom += len;
+	}
+    }
+
+  /* Update records for the slots the non-options now occupy.  */
+
+  d->__first_nonopt += (d->optind - d->__last_nonopt);
+  d->__last_nonopt = d->optind;
+}
+
+/* Initialize the internal data when the first call is made.  */
+
+static const char *
+_getopt_initialize (int argc, char **argv, const char *optstring,
+		    int posixly_correct, struct _getopt_data *d)
+{
+  /* Start processing options with ARGV-element 1 (since ARGV-element 0
+     is the program name); the sequence of previously skipped
+     non-option ARGV-elements is empty.  */
+
+  d->__first_nonopt = d->__last_nonopt = d->optind;
+
+  d->__nextchar = NULL;
+
+  d->__posixly_correct = posixly_correct || !!getenv ("POSIXLY_CORRECT");
+
+  /* Determine how to handle the ordering of options and nonoptions.  */
+
+  if (optstring[0] == '-')
+    {
+      d->__ordering = RETURN_IN_ORDER;
+      ++optstring;
+    }
+  else if (optstring[0] == '+')
+    {
+      d->__ordering = REQUIRE_ORDER;
+      ++optstring;
+    }
+  else if (d->__posixly_correct)
+    d->__ordering = REQUIRE_ORDER;
+  else
+    d->__ordering = PERMUTE;
+
+#if defined _LIBC && defined USE_NONOPTION_FLAGS
+  if (!d->__posixly_correct
+      && argc == __libc_argc && argv == __libc_argv)
+    {
+      if (d->__nonoption_flags_max_len == 0)
+	{
+	  if (__getopt_nonoption_flags == NULL
+	      || __getopt_nonoption_flags[0] == '\0')
+	    d->__nonoption_flags_max_len = -1;
+	  else
+	    {
+	      const char *orig_str = __getopt_nonoption_flags;
+	      int len = d->__nonoption_flags_max_len = strlen (orig_str);
+	      if (d->__nonoption_flags_max_len < argc)
+		d->__nonoption_flags_max_len = argc;
+	      __getopt_nonoption_flags =
+		(char *) malloc (d->__nonoption_flags_max_len);
+	      if (__getopt_nonoption_flags == NULL)
+		d->__nonoption_flags_max_len = -1;
+	      else
+		memset (__mempcpy (__getopt_nonoption_flags, orig_str, len),
+			'\0', d->__nonoption_flags_max_len - len);
+	    }
+	}
+      d->__nonoption_flags_len = d->__nonoption_flags_max_len;
+    }
+  else
+    d->__nonoption_flags_len = 0;
+#endif
+
+  return optstring;
+}
+
+/* Scan elements of ARGV (whose length is ARGC) for option characters
+   given in OPTSTRING.
+
+   If an element of ARGV starts with '-', and is not exactly "-" or "--",
+   then it is an option element.  The characters of this element
+   (aside from the initial '-') are option characters.  If `getopt'
+   is called repeatedly, it returns successively each of the option characters
+   from each of the option elements.
+
+   If `getopt' finds another option character, it returns that character,
+   updating `optind' and `nextchar' so that the next call to `getopt' can
+   resume the scan with the following option character or ARGV-element.
+
+   If there are no more option characters, `getopt' returns -1.
+   Then `optind' is the index in ARGV of the first ARGV-element
+   that is not an option.  (The ARGV-elements have been permuted
+   so that those that are not options now come last.)
+
+   OPTSTRING is a string containing the legitimate option characters.
+   If an option character is seen that is not listed in OPTSTRING,
+   return '?' after printing an error message.  If you set `opterr' to
+   zero, the error message is suppressed but we still return '?'.
+
+   If a char in OPTSTRING is followed by a colon, that means it wants an arg,
+   so the following text in the same ARGV-element, or the text of the following
+   ARGV-element, is returned in `optarg'.  Two colons mean an option that
+   wants an optional arg; if there is text in the current ARGV-element,
+   it is returned in `optarg', otherwise `optarg' is set to zero.
+
+   If OPTSTRING starts with `-' or `+', it requests different methods of
+   handling the non-option ARGV-elements.
+   See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.
+
+   Long-named options begin with `--' instead of `-'.
+   Their names may be abbreviated as long as the abbreviation is unique
+   or is an exact match for some defined option.  If they have an
+   argument, it follows the option name in the same ARGV-element, separated
+   from the option name by a `=', or else the in next ARGV-element.
+   When `getopt' finds a long-named option, it returns 0 if that option's
+   `flag' field is nonzero, the value of the option's `val' field
+   if the `flag' field is zero.
+
+   LONGOPTS is a vector of `struct option' terminated by an
+   element containing a name which is zero.
+
+   LONGIND returns the index in LONGOPT of the long-named option found.
+   It is only valid when a long-named option has been found by the most
+   recent call.
+
+   If LONG_ONLY is nonzero, '-' as well as '--' can introduce
+   long-named options.
+
+   If POSIXLY_CORRECT is nonzero, behave as if the POSIXLY_CORRECT
+   environment variable were set.  */
+
+int
+_getopt_internal_r (int argc, char **argv, const char *optstring,
+		    const struct option *longopts, int *longind,
+		    int long_only, int posixly_correct, struct _getopt_data *d)
+{
+  int print_errors = d->opterr;
+  if (optstring[0] == ':')
+    print_errors = 0;
+
+  if (argc < 1)
+    return -1;
+
+  d->optarg = NULL;
+
+  if (d->optind == 0 || !d->__initialized)
+    {
+      if (d->optind == 0)
+	d->optind = 1;	/* Don't scan ARGV[0], the program name.  */
+      optstring = _getopt_initialize (argc, argv, optstring,
+				      posixly_correct, d);
+      d->__initialized = 1;
+    }
+
+  /* Test whether ARGV[optind] points to a non-option argument.
+     Either it does not have option syntax, or there is an environment flag
+     from the shell indicating it is not an option.  The later information
+     is only used when the used in the GNU libc.  */
+#if defined _LIBC && defined USE_NONOPTION_FLAGS
+# define NONOPTION_P (argv[d->optind][0] != '-' || argv[d->optind][1] == '\0' \
+		      || (d->optind < d->__nonoption_flags_len		      \
+			  && __getopt_nonoption_flags[d->optind] == '1'))
+#else
+# define NONOPTION_P (argv[d->optind][0] != '-' || argv[d->optind][1] == '\0')
+#endif
+
+  if (d->__nextchar == NULL || *d->__nextchar == '\0')
+    {
+      /* Advance to the next ARGV-element.  */
+
+      /* Give FIRST_NONOPT & LAST_NONOPT rational values if OPTIND has been
+	 moved back by the user (who may also have changed the arguments).  */
+      if (d->__last_nonopt > d->optind)
+	d->__last_nonopt = d->optind;
+      if (d->__first_nonopt > d->optind)
+	d->__first_nonopt = d->optind;
+
+      if (d->__ordering == PERMUTE)
+	{
+	  /* If we have just processed some options following some non-options,
+	     exchange them so that the options come first.  */
+
+	  if (d->__first_nonopt != d->__last_nonopt
+	      && d->__last_nonopt != d->optind)
+	    exchange ((char **) argv, d);
+	  else if (d->__last_nonopt != d->optind)
+	    d->__first_nonopt = d->optind;
+
+	  /* Skip any additional non-options
+	     and extend the range of non-options previously skipped.  */
+
+	  while (d->optind < argc && NONOPTION_P)
+	    d->optind++;
+	  d->__last_nonopt = d->optind;
+	}
+
+      /* The special ARGV-element `--' means premature end of options.
+	 Skip it like a null option,
+	 then exchange with previous non-options as if it were an option,
+	 then skip everything else like a non-option.  */
+
+      if (d->optind != argc && !strcmp (argv[d->optind], "--"))
+	{
+	  d->optind++;
+
+	  if (d->__first_nonopt != d->__last_nonopt
+	      && d->__last_nonopt != d->optind)
+	    exchange ((char **) argv, d);
+	  else if (d->__first_nonopt == d->__last_nonopt)
+	    d->__first_nonopt = d->optind;
+	  d->__last_nonopt = argc;
+
+	  d->optind = argc;
+	}
+
+      /* If we have done all the ARGV-elements, stop the scan
+	 and back over any non-options that we skipped and permuted.  */
+
+      if (d->optind == argc)
+	{
+	  /* Set the next-arg-index to point at the non-options
+	     that we previously skipped, so the caller will digest them.  */
+	  if (d->__first_nonopt != d->__last_nonopt)
+	    d->optind = d->__first_nonopt;
+	  return -1;
+	}
+
+      /* If we have come to a non-option and did not permute it,
+	 either stop the scan or describe it to the caller and pass it by.  */
+
+      if (NONOPTION_P)
+	{
+	  if (d->__ordering == REQUIRE_ORDER)
+	    return -1;
+	  d->optarg = argv[d->optind++];
+	  return 1;
+	}
+
+      /* We have found another option-ARGV-element.
+	 Skip the initial punctuation.  */
+
+      d->__nextchar = (argv[d->optind] + 1
+		  + (longopts != NULL && argv[d->optind][1] == '-'));
+    }
+
+  /* Decode the current option-ARGV-element.  */
+
+  /* Check whether the ARGV-element is a long option.
+
+     If long_only and the ARGV-element has the form "-f", where f is
+     a valid short option, don't consider it an abbreviated form of
+     a long option that starts with f.  Otherwise there would be no
+     way to give the -f short option.
+
+     On the other hand, if there's a long option "fubar" and
+     the ARGV-element is "-fu", do consider that an abbreviation of
+     the long option, just like "--fu", and not "-f" with arg "u".
+
+     This distinction seems to be the most useful approach.  */
+
+  if (longopts != NULL
+      && (argv[d->optind][1] == '-'
+	  || (long_only && (argv[d->optind][2]
+			    || !strchr (optstring, argv[d->optind][1])))))
+    {
+      char *nameend;
+      const struct option *p;
+      const struct option *pfound = NULL;
+      int exact = 0;
+      int ambig = 0;
+      int indfound = -1;
+      int option_index;
+
+      for (nameend = d->__nextchar; *nameend && *nameend != '='; nameend++)
+	/* Do nothing.  */ ;
+
+      /* Test all long options for either exact match
+	 or abbreviated matches.  */
+      for (p = longopts, option_index = 0; p->name; p++, option_index++)
+	if (!strncmp (p->name, d->__nextchar, nameend - d->__nextchar))
+	  {
+	    if ((unsigned int) (nameend - d->__nextchar)
+		== (unsigned int) strlen (p->name))
+	      {
+		/* Exact match found.  */
+		pfound = p;
+		indfound = option_index;
+		exact = 1;
+		break;
+	      }
+	    else if (pfound == NULL)
+	      {
+		/* First nonexact match found.  */
+		pfound = p;
+		indfound = option_index;
+	      }
+	    else if (long_only
+		     || pfound->has_arg != p->has_arg
+		     || pfound->flag != p->flag
+		     || pfound->val != p->val)
+	      /* Second or later nonexact match found.  */
+	      ambig = 1;
+	  }
+
+      if (ambig && !exact)
+	{
+	  if (print_errors)
+	    {
+#if defined _LIBC && defined USE_IN_LIBIO
+	      char *buf;
+
+	      if (__asprintf (&buf, _("%s: option `%s' is ambiguous\n"),
+			      argv[0], argv[d->optind]) >= 0)
+		{
+		  _IO_flockfile (stderr);
+
+		  int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+		  ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
+
+		  __fxprintf (NULL, "%s", buf);
+
+		  ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+		  _IO_funlockfile (stderr);
+
+		  free (buf);
+		}
+#else
+	      fprintf (stderr, _("%s: option `%s' is ambiguous\n"),
+		       argv[0], argv[d->optind]);
+#endif
+	    }
+	  d->__nextchar += strlen (d->__nextchar);
+	  d->optind++;
+	  d->optopt = 0;
+	  return '?';
+	}
+
+      if (pfound != NULL)
+	{
+	  option_index = indfound;
+	  d->optind++;
+	  if (*nameend)
+	    {
+	      /* Don't test has_arg with >, because some C compilers don't
+		 allow it to be used on enums.  */
+	      if (pfound->has_arg)
+		d->optarg = nameend + 1;
+	      else
+		{
+		  if (print_errors)
+		    {
+#if defined _LIBC && defined USE_IN_LIBIO
+		      char *buf;
+		      int n;
+#endif
+
+		      if (argv[d->optind - 1][1] == '-')
+			{
+			  /* --option */
+#if defined _LIBC && defined USE_IN_LIBIO
+			  n = __asprintf (&buf, _("\
+%s: option `--%s' doesn't allow an argument\n"),
+					  argv[0], pfound->name);
+#else
+			  fprintf (stderr, _("\
+%s: option `--%s' doesn't allow an argument\n"),
+				   argv[0], pfound->name);
+#endif
+			}
+		      else
+			{
+			  /* +option or -option */
+#if defined _LIBC && defined USE_IN_LIBIO
+			  n = __asprintf (&buf, _("\
+%s: option `%c%s' doesn't allow an argument\n"),
+					  argv[0], argv[d->optind - 1][0],
+					  pfound->name);
+#else
+			  fprintf (stderr, _("\
+%s: option `%c%s' doesn't allow an argument\n"),
+				   argv[0], argv[d->optind - 1][0],
+				   pfound->name);
+#endif
+			}
+
+#if defined _LIBC && defined USE_IN_LIBIO
+		      if (n >= 0)
+			{
+			  _IO_flockfile (stderr);
+
+			  int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+			  ((_IO_FILE *) stderr)->_flags2
+			    |= _IO_FLAGS2_NOTCANCEL;
+
+			  __fxprintf (NULL, "%s", buf);
+
+			  ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+			  _IO_funlockfile (stderr);
+
+			  free (buf);
+			}
+#endif
+		    }
+
+		  d->__nextchar += strlen (d->__nextchar);
+
+		  d->optopt = pfound->val;
+		  return '?';
+		}
+	    }
+	  else if (pfound->has_arg == 1)
+	    {
+	      if (d->optind < argc)
+		d->optarg = argv[d->optind++];
+	      else
+		{
+		  if (print_errors)
+		    {
+#if defined _LIBC && defined USE_IN_LIBIO
+		      char *buf;
+
+		      if (__asprintf (&buf, _("\
+%s: option `%s' requires an argument\n"),
+				      argv[0], argv[d->optind - 1]) >= 0)
+			{
+			  _IO_flockfile (stderr);
+
+			  int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+			  ((_IO_FILE *) stderr)->_flags2
+			    |= _IO_FLAGS2_NOTCANCEL;
+
+			  __fxprintf (NULL, "%s", buf);
+
+			  ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+			  _IO_funlockfile (stderr);
+
+			  free (buf);
+			}
+#else
+		      fprintf (stderr,
+			       _("%s: option `%s' requires an argument\n"),
+			       argv[0], argv[d->optind - 1]);
+#endif
+		    }
+		  d->__nextchar += strlen (d->__nextchar);
+		  d->optopt = pfound->val;
+		  return optstring[0] == ':' ? ':' : '?';
+		}
+	    }
+	  d->__nextchar += strlen (d->__nextchar);
+	  if (longind != NULL)
+	    *longind = option_index;
+	  if (pfound->flag)
+	    {
+	      *(pfound->flag) = pfound->val;
+	      return 0;
+	    }
+	  return pfound->val;
+	}
+
+      /* Can't find it as a long option.  If this is not getopt_long_only,
+	 or the option starts with '--' or is not a valid short
+	 option, then it's an error.
+	 Otherwise interpret it as a short option.  */
+      if (!long_only || argv[d->optind][1] == '-'
+	  || strchr (optstring, *d->__nextchar) == NULL)
+	{
+	  if (print_errors)
+	    {
+#if defined _LIBC && defined USE_IN_LIBIO
+	      char *buf;
+	      int n;
+#endif
+
+	      if (argv[d->optind][1] == '-')
+		{
+		  /* --option */
+#if defined _LIBC && defined USE_IN_LIBIO
+		  n = __asprintf (&buf, _("%s: unrecognized option `--%s'\n"),
+				  argv[0], d->__nextchar);
+#else
+		  fprintf (stderr, _("%s: unrecognized option `--%s'\n"),
+			   argv[0], d->__nextchar);
+#endif
+		}
+	      else
+		{
+		  /* +option or -option */
+#if defined _LIBC && defined USE_IN_LIBIO
+		  n = __asprintf (&buf, _("%s: unrecognized option `%c%s'\n"),
+				  argv[0], argv[d->optind][0], d->__nextchar);
+#else
+		  fprintf (stderr, _("%s: unrecognized option `%c%s'\n"),
+			   argv[0], argv[d->optind][0], d->__nextchar);
+#endif
+		}
+
+#if defined _LIBC && defined USE_IN_LIBIO
+	      if (n >= 0)
+		{
+		  _IO_flockfile (stderr);
+
+		  int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+		  ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
+
+		  __fxprintf (NULL, "%s", buf);
+
+		  ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+		  _IO_funlockfile (stderr);
+
+		  free (buf);
+		}
+#endif
+	    }
+	  d->__nextchar = (char *) "";
+	  d->optind++;
+	  d->optopt = 0;
+	  return '?';
+	}
+    }
+
+  /* Look at and handle the next short option-character.  */
+
+  {
+    char c = *d->__nextchar++;
+    char *temp = strchr (optstring, c);
+
+    /* Increment `optind' when we start to process its last character.  */
+    if (*d->__nextchar == '\0')
+      ++d->optind;
+
+    if (temp == NULL || c == ':')
+      {
+	if (print_errors)
+	  {
+#if defined _LIBC && defined USE_IN_LIBIO
+	      char *buf;
+	      int n;
+#endif
+
+	    if (d->__posixly_correct)
+	      {
+		/* 1003.2 specifies the format of this message.  */
+#if defined _LIBC && defined USE_IN_LIBIO
+		n = __asprintf (&buf, _("%s: illegal option -- %c\n"),
+				argv[0], c);
+#else
+		fprintf (stderr, _("%s: illegal option -- %c\n"), argv[0], c);
+#endif
+	      }
+	    else
+	      {
+#if defined _LIBC && defined USE_IN_LIBIO
+		n = __asprintf (&buf, _("%s: invalid option -- %c\n"),
+				argv[0], c);
+#else
+		fprintf (stderr, _("%s: invalid option -- %c\n"), argv[0], c);
+#endif
+	      }
+
+#if defined _LIBC && defined USE_IN_LIBIO
+	    if (n >= 0)
+	      {
+		_IO_flockfile (stderr);
+
+		int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+		((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
+
+		__fxprintf (NULL, "%s", buf);
+
+		((_IO_FILE *) stderr)->_flags2 = old_flags2;
+		_IO_funlockfile (stderr);
+
+		free (buf);
+	      }
+#endif
+	  }
+	d->optopt = c;
+	return '?';
+      }
+    /* Convenience. Treat POSIX -W foo same as long option --foo */
+    if (temp[0] == 'W' && temp[1] == ';')
+      {
+	char *nameend;
+	const struct option *p;
+	const struct option *pfound = NULL;
+	int exact = 0;
+	int ambig = 0;
+	int indfound = 0;
+	int option_index;
+
+	/* This is an option that requires an argument.  */
+	if (*d->__nextchar != '\0')
+	  {
+	    d->optarg = d->__nextchar;
+	    /* If we end this ARGV-element by taking the rest as an arg,
+	       we must advance to the next element now.  */
+	    d->optind++;
+	  }
+	else if (d->optind == argc)
+	  {
+	    if (print_errors)
+	      {
+		/* 1003.2 specifies the format of this message.  */
+#if defined _LIBC && defined USE_IN_LIBIO
+		char *buf;
+
+		if (__asprintf (&buf,
+				_("%s: option requires an argument -- %c\n"),
+				argv[0], c) >= 0)
+		  {
+		    _IO_flockfile (stderr);
+
+		    int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+		    ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
+
+		    __fxprintf (NULL, "%s", buf);
+
+		    ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+		    _IO_funlockfile (stderr);
+
+		    free (buf);
+		  }
+#else
+		fprintf (stderr, _("%s: option requires an argument -- %c\n"),
+			 argv[0], c);
+#endif
+	      }
+	    d->optopt = c;
+	    if (optstring[0] == ':')
+	      c = ':';
+	    else
+	      c = '?';
+	    return c;
+	  }
+	else
+	  /* We already incremented `d->optind' once;
+	     increment it again when taking next ARGV-elt as argument.  */
+	  d->optarg = argv[d->optind++];
+
+	/* optarg is now the argument, see if it's in the
+	   table of longopts.  */
+
+	for (d->__nextchar = nameend = d->optarg; *nameend && *nameend != '=';
+	     nameend++)
+	  /* Do nothing.  */ ;
+
+	/* Test all long options for either exact match
+	   or abbreviated matches.  */
+	for (p = longopts, option_index = 0; p->name; p++, option_index++)
+	  if (!strncmp (p->name, d->__nextchar, nameend - d->__nextchar))
+	    {
+	      if ((unsigned int) (nameend - d->__nextchar) == strlen (p->name))
+		{
+		  /* Exact match found.  */
+		  pfound = p;
+		  indfound = option_index;
+		  exact = 1;
+		  break;
+		}
+	      else if (pfound == NULL)
+		{
+		  /* First nonexact match found.  */
+		  pfound = p;
+		  indfound = option_index;
+		}
+	      else
+		/* Second or later nonexact match found.  */
+		ambig = 1;
+	    }
+	if (ambig && !exact)
+	  {
+	    if (print_errors)
+	      {
+#if defined _LIBC && defined USE_IN_LIBIO
+		char *buf;
+
+		if (__asprintf (&buf, _("%s: option `-W %s' is ambiguous\n"),
+				argv[0], argv[d->optind]) >= 0)
+		  {
+		    _IO_flockfile (stderr);
+
+		    int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+		    ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
+
+		    __fxprintf (NULL, "%s", buf);
+
+		    ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+		    _IO_funlockfile (stderr);
+
+		    free (buf);
+		  }
+#else
+		fprintf (stderr, _("%s: option `-W %s' is ambiguous\n"),
+			 argv[0], argv[d->optind]);
+#endif
+	      }
+	    d->__nextchar += strlen (d->__nextchar);
+	    d->optind++;
+	    return '?';
+	  }
+	if (pfound != NULL)
+	  {
+	    option_index = indfound;
+	    if (*nameend)
+	      {
+		/* Don't test has_arg with >, because some C compilers don't
+		   allow it to be used on enums.  */
+		if (pfound->has_arg)
+		  d->optarg = nameend + 1;
+		else
+		  {
+		    if (print_errors)
+		      {
+#if defined _LIBC && defined USE_IN_LIBIO
+			char *buf;
+
+			if (__asprintf (&buf, _("\
+%s: option `-W %s' doesn't allow an argument\n"),
+					argv[0], pfound->name) >= 0)
+			  {
+			    _IO_flockfile (stderr);
+
+			    int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+			    ((_IO_FILE *) stderr)->_flags2
+			      |= _IO_FLAGS2_NOTCANCEL;
+
+			    __fxprintf (NULL, "%s", buf);
+
+			    ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+			    _IO_funlockfile (stderr);
+
+			    free (buf);
+			  }
+#else
+			fprintf (stderr, _("\
+%s: option `-W %s' doesn't allow an argument\n"),
+				 argv[0], pfound->name);
+#endif
+		      }
+
+		    d->__nextchar += strlen (d->__nextchar);
+		    return '?';
+		  }
+	      }
+	    else if (pfound->has_arg == 1)
+	      {
+		if (d->optind < argc)
+		  d->optarg = argv[d->optind++];
+		else
+		  {
+		    if (print_errors)
+		      {
+#if defined _LIBC && defined USE_IN_LIBIO
+			char *buf;
+
+			if (__asprintf (&buf, _("\
+%s: option `%s' requires an argument\n"),
+					argv[0], argv[d->optind - 1]) >= 0)
+			  {
+			    _IO_flockfile (stderr);
+
+			    int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+			    ((_IO_FILE *) stderr)->_flags2
+			      |= _IO_FLAGS2_NOTCANCEL;
+
+			    __fxprintf (NULL, "%s", buf);
+
+			    ((_IO_FILE *) stderr)->_flags2 = old_flags2;
+			    _IO_funlockfile (stderr);
+
+			    free (buf);
+			  }
+#else
+			fprintf (stderr,
+				 _("%s: option `%s' requires an argument\n"),
+				 argv[0], argv[d->optind - 1]);
+#endif
+		      }
+		    d->__nextchar += strlen (d->__nextchar);
+		    return optstring[0] == ':' ? ':' : '?';
+		  }
+	      }
+	    d->__nextchar += strlen (d->__nextchar);
+	    if (longind != NULL)
+	      *longind = option_index;
+	    if (pfound->flag)
+	      {
+		*(pfound->flag) = pfound->val;
+		return 0;
+	      }
+	    return pfound->val;
+	  }
+	  d->__nextchar = NULL;
+	  return 'W';	/* Let the application handle it.   */
+      }
+    if (temp[1] == ':')
+      {
+	if (temp[2] == ':')
+	  {
+	    /* This is an option that accepts an argument optionally.  */
+	    if (*d->__nextchar != '\0')
+	      {
+		d->optarg = d->__nextchar;
+		d->optind++;
+	      }
+	    else
+	      d->optarg = NULL;
+	    d->__nextchar = NULL;
+	  }
+	else
+	  {
+	    /* This is an option that requires an argument.  */
+	    if (*d->__nextchar != '\0')
+	      {
+		d->optarg = d->__nextchar;
+		/* If we end this ARGV-element by taking the rest as an arg,
+		   we must advance to the next element now.  */
+		d->optind++;
+	      }
+	    else if (d->optind == argc)
+	      {
+		if (print_errors)
+		  {
+		    /* 1003.2 specifies the format of this message.  */
+#if defined _LIBC && defined USE_IN_LIBIO
+		    char *buf;
+
+		    if (__asprintf (&buf, _("\
+%s: option requires an argument -- %c\n"),
+				    argv[0], c) >= 0)
+		      {
+			_IO_flockfile (stderr);
+
+			int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+			((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
+
+			__fxprintf (NULL, "%s", buf);
+
+			((_IO_FILE *) stderr)->_flags2 = old_flags2;
+			_IO_funlockfile (stderr);
+
+			free (buf);
+		      }
+#else
+		    fprintf (stderr,
+			     _("%s: option requires an argument -- %c\n"),
+			     argv[0], c);
+#endif
+		  }
+		d->optopt = c;
+		if (optstring[0] == ':')
+		  c = ':';
+		else
+		  c = '?';
+	      }
+	    else
+	      /* We already incremented `optind' once;
+		 increment it again when taking next ARGV-elt as argument.  */
+	      d->optarg = argv[d->optind++];
+	    d->__nextchar = NULL;
+	  }
+      }
+    return c;
+  }
+}
+
+int
+_getopt_internal (int argc, char **argv, const char *optstring,
+		  const struct option *longopts, int *longind,
+		  int long_only, int posixly_correct)
+{
+  int result;
+
+  getopt_data.optind = optind;
+  getopt_data.opterr = opterr;
+
+  result = _getopt_internal_r (argc, argv, optstring, longopts, longind,
+			       long_only, posixly_correct, &getopt_data);
+
+  optind = getopt_data.optind;
+  optarg = getopt_data.optarg;
+  optopt = getopt_data.optopt;
+
+  return result;
+}
+
+/* glibc gets a LSB-compliant getopt.
+   Standalone applications get a POSIX-compliant getopt.  */
+#if _LIBC
+enum { POSIXLY_CORRECT = 0 };
+#else
+enum { POSIXLY_CORRECT = 1 };
+#endif
+
+int
+getopt (int argc, char *const *argv, const char *optstring)
+{
+  return _getopt_internal (argc, (char **) argv, optstring, NULL, NULL, 0,
+			   POSIXLY_CORRECT);
+}
+
+
+#ifdef TEST
+
+/* Compile with -DTEST to make an executable for use in testing
+   the above definition of `getopt'.  */
+
+int
+main (int argc, char **argv)
+{
+  int c;
+  int digit_optind = 0;
+
+  while (1)
+    {
+      int this_option_optind = optind ? optind : 1;
+
+      c = getopt (argc, argv, "abc:d:0123456789");
+      if (c == -1)
+	break;
+
+      switch (c)
+	{
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+	  if (digit_optind != 0 && digit_optind != this_option_optind)
+	    printf ("digits occur in two different argv-elements.\n");
+	  digit_optind = this_option_optind;
+	  printf ("option %c\n", c);
+	  break;
+
+	case 'a':
+	  printf ("option a\n");
+	  break;
+
+	case 'b':
+	  printf ("option b\n");
+	  break;
+
+	case 'c':
+	  printf ("option c with value `%s'\n", optarg);
+	  break;
+
+	case '?':
+	  break;
+
+	default:
+	  printf ("?? getopt returned character code 0%o ??\n", c);
+	}
+    }
+
+  if (optind < argc)
+    {
+      printf ("non-option ARGV-elements: ");
+      while (optind < argc)
+	printf ("%s ", argv[optind++]);
+      printf ("\n");
+    }
+
+  exit (0);
+}
+
+#endif /* TEST */
diff --git a/src/bin/m4/lib/getopt1.c b/src/bin/m4/lib/getopt1.c
new file mode 100644
index 0000000000..cc0746ea43
--- /dev/null
+++ b/src/bin/m4/lib/getopt1.c
@@ -0,0 +1,171 @@
+/* getopt_long and getopt_long_only entry points for GNU getopt.
+   Copyright (C) 1987,88,89,90,91,92,93,94,96,97,98,2004,2006
+     Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifdef _LIBC
+# include <getopt.h>
+#else
+# include <config.h>
+# include "getopt.h"
+#endif
+#include "getopt_int.h"
+
+#include <stdio.h>
+
+/* This needs to come after some library #include
+   to get __GNU_LIBRARY__ defined.  */
+#ifdef __GNU_LIBRARY__
+#include <stdlib.h>
+#endif
+
+#ifndef	NULL
+#define NULL 0
+#endif
+
+int
+getopt_long (int argc, char *__getopt_argv_const *argv, const char *options,
+	     const struct option *long_options, int *opt_index)
+{
+  return _getopt_internal (argc, (char **) argv, options, long_options,
+			   opt_index, 0, 0);
+}
+
+int
+_getopt_long_r (int argc, char **argv, const char *options,
+		const struct option *long_options, int *opt_index,
+		struct _getopt_data *d)
+{
+  return _getopt_internal_r (argc, argv, options, long_options, opt_index,
+			     0, 0, d);
+}
+
+/* Like getopt_long, but '-' as well as '--' can indicate a long option.
+   If an option that starts with '-' (not '--') doesn't match a long option,
+   but does match a short option, it is parsed as a short option
+   instead.  */
+
+int
+getopt_long_only (int argc, char *__getopt_argv_const *argv,
+		  const char *options,
+		  const struct option *long_options, int *opt_index)
+{
+  return _getopt_internal (argc, (char **) argv, options, long_options,
+			   opt_index, 1, 0);
+}
+
+int
+_getopt_long_only_r (int argc, char **argv, const char *options,
+		     const struct option *long_options, int *opt_index,
+		     struct _getopt_data *d)
+{
+  return _getopt_internal_r (argc, argv, options, long_options, opt_index,
+			     1, 0, d);
+}
+
+
+#ifdef TEST
+
+#include <stdio.h>
+
+int
+main (int argc, char **argv)
+{
+  int c;
+  int digit_optind = 0;
+
+  while (1)
+    {
+      int this_option_optind = optind ? optind : 1;
+      int option_index = 0;
+      static struct option long_options[] =
+      {
+	{"add", 1, 0, 0},
+	{"append", 0, 0, 0},
+	{"delete", 1, 0, 0},
+	{"verbose", 0, 0, 0},
+	{"create", 0, 0, 0},
+	{"file", 1, 0, 0},
+	{0, 0, 0, 0}
+      };
+
+      c = getopt_long (argc, argv, "abc:d:0123456789",
+		       long_options, &option_index);
+      if (c == -1)
+	break;
+
+      switch (c)
+	{
+	case 0:
+	  printf ("option %s", long_options[option_index].name);
+	  if (optarg)
+	    printf (" with arg %s", optarg);
+	  printf ("\n");
+	  break;
+
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+	  if (digit_optind != 0 && digit_optind != this_option_optind)
+	    printf ("digits occur in two different argv-elements.\n");
+	  digit_optind = this_option_optind;
+	  printf ("option %c\n", c);
+	  break;
+
+	case 'a':
+	  printf ("option a\n");
+	  break;
+
+	case 'b':
+	  printf ("option b\n");
+	  break;
+
+	case 'c':
+	  printf ("option c with value `%s'\n", optarg);
+	  break;
+
+	case 'd':
+	  printf ("option d with value `%s'\n", optarg);
+	  break;
+
+	case '?':
+	  break;
+
+	default:
+	  printf ("?? getopt returned character code 0%o ??\n", c);
+	}
+    }
+
+  if (optind < argc)
+    {
+      printf ("non-option ARGV-elements: ");
+      while (optind < argc)
+	printf ("%s ", argv[optind++]);
+      printf ("\n");
+    }
+
+  exit (0);
+}
+
+#endif /* TEST */
diff --git a/src/bin/m4/lib/getopt_.h b/src/bin/m4/lib/getopt_.h
new file mode 100644
index 0000000000..27fce3dc79
--- /dev/null
+++ b/src/bin/m4/lib/getopt_.h
@@ -0,0 +1,226 @@
+/* Declarations for getopt.
+   Copyright (C) 1989-1994,1996-1999,2001,2003,2004,2005,2006
+   Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GETOPT_H
+
+#ifndef __need_getopt
+# define _GETOPT_H 1
+#endif
+
+/* Standalone applications should #define __GETOPT_PREFIX to an
+   identifier that prefixes the external functions and variables
+   defined in this header.  When this happens, include the
+   headers that might declare getopt so that they will not cause
+   confusion if included after this file.  Then systematically rename
+   identifiers so that they do not collide with the system functions
+   and variables.  Renaming avoids problems with some compilers and
+   linkers.  */
+#if defined __GETOPT_PREFIX && !defined __need_getopt
+# include <stdlib.h>
+# include <stdio.h>
+# include <unistd.h>
+# undef __need_getopt
+# undef getopt
+# undef getopt_long
+# undef getopt_long_only
+# undef optarg
+# undef opterr
+# undef optind
+# undef optopt
+# define __GETOPT_CONCAT(x, y) x ## y
+# define __GETOPT_XCONCAT(x, y) __GETOPT_CONCAT (x, y)
+# define __GETOPT_ID(y) __GETOPT_XCONCAT (__GETOPT_PREFIX, y)
+# define getopt __GETOPT_ID (getopt)
+# define getopt_long __GETOPT_ID (getopt_long)
+# define getopt_long_only __GETOPT_ID (getopt_long_only)
+# define optarg __GETOPT_ID (optarg)
+# define opterr __GETOPT_ID (opterr)
+# define optind __GETOPT_ID (optind)
+# define optopt __GETOPT_ID (optopt)
+#endif
+
+/* Standalone applications get correct prototypes for getopt_long and
+   getopt_long_only; they declare "char **argv".  libc uses prototypes
+   with "char *const *argv" that are incorrect because getopt_long and
+   getopt_long_only can permute argv; this is required for backward
+   compatibility (e.g., for LSB 2.0.1).
+
+   This used to be `#if defined __GETOPT_PREFIX && !defined __need_getopt',
+   but it caused redefinition warnings if both unistd.h and getopt.h were
+   included, since unistd.h includes getopt.h having previously defined
+   __need_getopt.
+
+   The only place where __getopt_argv_const is used is in definitions
+   of getopt_long and getopt_long_only below, but these are visible
+   only if __need_getopt is not defined, so it is quite safe to rewrite
+   the conditional as follows:
+*/
+#if !defined __need_getopt
+# if defined __GETOPT_PREFIX
+#  define __getopt_argv_const /* empty */
+# else
+#  define __getopt_argv_const const
+# endif
+#endif
+
+/* If __GNU_LIBRARY__ is not already defined, either we are being used
+   standalone, or this is the first header included in the source file.
+   If we are being used with glibc, we need to include <features.h>, but
+   that does not exist if we are standalone.  So: if __GNU_LIBRARY__ is
+   not defined, include <ctype.h>, which will pull in <features.h> for us
+   if it's from glibc.  (Why ctype.h?  It's guaranteed to exist and it
+   doesn't flood the namespace with stuff the way some other headers do.)  */
+#if !defined __GNU_LIBRARY__
+# include <ctype.h>
+#endif
+
+#ifndef __THROW
+# ifndef __GNUC_PREREQ
+#  define __GNUC_PREREQ(maj, min) (0)
+# endif
+# if defined __cplusplus && __GNUC_PREREQ (2,8)
+#  define __THROW	throw ()
+# else
+#  define __THROW
+# endif
+#endif
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* For communication from `getopt' to the caller.
+   When `getopt' finds an option that takes an argument,
+   the argument value is returned here.
+   Also, when `ordering' is RETURN_IN_ORDER,
+   each non-option ARGV-element is returned here.  */
+
+extern char *optarg;
+
+/* Index in ARGV of the next element to be scanned.
+   This is used for communication to and from the caller
+   and for communication between successive calls to `getopt'.
+
+   On entry to `getopt', zero means this is the first call; initialize.
+
+   When `getopt' returns -1, this is the index of the first of the
+   non-option elements that the caller should itself scan.
+
+   Otherwise, `optind' communicates from one call to the next
+   how much of ARGV has been scanned so far.  */
+
+extern int optind;
+
+/* Callers store zero here to inhibit the error message `getopt' prints
+   for unrecognized options.  */
+
+extern int opterr;
+
+/* Set to an option character which was unrecognized.  */
+
+extern int optopt;
+
+#ifndef __need_getopt
+/* Describe the long-named options requested by the application.
+   The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
+   of `struct option' terminated by an element containing a name which is
+   zero.
+
+   The field `has_arg' is:
+   no_argument		(or 0) if the option does not take an argument,
+   required_argument	(or 1) if the option requires an argument,
+   optional_argument	(or 2) if the option takes an optional argument.
+
+   If the field `flag' is not NULL, it points to a variable that is set
+   to the value given in the field `val' when the option is found, but
+   left unchanged if the option is not found.
+
+   To have a long-named option do something other than set an `int' to
+   a compiled-in constant, such as set a value from `optarg', set the
+   option's `flag' field to zero and its `val' field to a nonzero
+   value (the equivalent single-letter option character, if there is
+   one).  For long options that have a zero `flag' field, `getopt'
+   returns the contents of the `val' field.  */
+
+struct option
+{
+  const char *name;
+  /* has_arg can't be an enum because some compilers complain about
+     type mismatches in all the code that assumes it is an int.  */
+  int has_arg;
+  int *flag;
+  int val;
+};
+
+/* Names for the values of the `has_arg' field of `struct option'.  */
+
+# define no_argument		0
+# define required_argument	1
+# define optional_argument	2
+#endif	/* need getopt */
+
+
+/* Get definitions and prototypes for functions to process the
+   arguments in ARGV (ARGC of them, minus the program name) for
+   options given in OPTS.
+
+   Return the option character from OPTS just read.  Return -1 when
+   there are no more options.  For unrecognized options, or options
+   missing arguments, `optopt' is set to the option letter, and '?' is
+   returned.
+
+   The OPTS string is a list of characters which are recognized option
+   letters, optionally followed by colons, specifying that that letter
+   takes an argument, to be placed in `optarg'.
+
+   If a letter in OPTS is followed by two colons, its argument is
+   optional.  This behavior is specific to the GNU `getopt'.
+
+   The argument `--' causes premature termination of argument
+   scanning, explicitly telling `getopt' that there are no more
+   options.
+
+   If OPTS begins with `-', then non-option arguments are treated as
+   arguments to the option '\1'.  This behavior is specific to the GNU
+   `getopt'.  If OPTS begins with `+', or POSIXLY_CORRECT is set in
+   the environment, then do not permute arguments.  */
+
+extern int getopt (int ___argc, char *const *___argv, const char *__shortopts)
+       __THROW;
+
+#ifndef __need_getopt
+extern int getopt_long (int ___argc, char *__getopt_argv_const *___argv,
+			const char *__shortopts,
+		        const struct option *__longopts, int *__longind)
+       __THROW;
+extern int getopt_long_only (int ___argc, char *__getopt_argv_const *___argv,
+			     const char *__shortopts,
+		             const struct option *__longopts, int *__longind)
+       __THROW;
+
+#endif
+
+#ifdef	__cplusplus
+}
+#endif
+
+/* Make sure we later can get all the definitions and declarations.  */
+#undef __need_getopt
+
+#endif /* getopt.h */
diff --git a/src/bin/m4/lib/getopt_int.h b/src/bin/m4/lib/getopt_int.h
new file mode 100644
index 0000000000..401579fd28
--- /dev/null
+++ b/src/bin/m4/lib/getopt_int.h
@@ -0,0 +1,131 @@
+/* Internal declarations for getopt.
+   Copyright (C) 1989-1994,1996-1999,2001,2003,2004
+   Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GETOPT_INT_H
+#define _GETOPT_INT_H	1
+
+extern int _getopt_internal (int ___argc, char **___argv,
+			     const char *__shortopts,
+		             const struct option *__longopts, int *__longind,
+			     int __long_only, int __posixly_correct);
+
+
+/* Reentrant versions which can handle parsing multiple argument
+   vectors at the same time.  */
+
+/* Data type for reentrant functions.  */
+struct _getopt_data
+{
+  /* These have exactly the same meaning as the corresponding global
+     variables, except that they are used for the reentrant
+     versions of getopt.  */
+  int optind;
+  int opterr;
+  int optopt;
+  char *optarg;
+
+  /* Internal members.  */
+
+  /* True if the internal members have been initialized.  */
+  int __initialized;
+
+  /* The next char to be scanned in the option-element
+     in which the last option character we returned was found.
+     This allows us to pick up the scan where we left off.
+
+     If this is zero, or a null string, it means resume the scan
+     by advancing to the next ARGV-element.  */
+  char *__nextchar;
+
+  /* Describe how to deal with options that follow non-option ARGV-elements.
+
+     If the caller did not specify anything,
+     the default is REQUIRE_ORDER if the environment variable
+     POSIXLY_CORRECT is defined, PERMUTE otherwise.
+
+     REQUIRE_ORDER means don't recognize them as options;
+     stop option processing when the first non-option is seen.
+     This is what Unix does.
+     This mode of operation is selected by either setting the environment
+     variable POSIXLY_CORRECT, or using `+' as the first character
+     of the list of option characters, or by calling getopt.
+
+     PERMUTE is the default.  We permute the contents of ARGV as we
+     scan, so that eventually all the non-options are at the end.
+     This allows options to be given in any order, even with programs
+     that were not written to expect this.
+
+     RETURN_IN_ORDER is an option available to programs that were
+     written to expect options and other ARGV-elements in any order
+     and that care about the ordering of the two.  We describe each
+     non-option ARGV-element as if it were the argument of an option
+     with character code 1.  Using `-' as the first character of the
+     list of option characters selects this mode of operation.
+
+     The special argument `--' forces an end of option-scanning regardless
+     of the value of `ordering'.  In the case of RETURN_IN_ORDER, only
+     `--' can cause `getopt' to return -1 with `optind' != ARGC.  */
+
+  enum
+    {
+      REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
+    } __ordering;
+
+  /* If the POSIXLY_CORRECT environment variable is set
+     or getopt was called.  */
+  int __posixly_correct;
+
+
+  /* Handle permutation of arguments.  */
+
+  /* Describe the part of ARGV that contains non-options that have
+     been skipped.  `first_nonopt' is the index in ARGV of the first
+     of them; `last_nonopt' is the index after the last of them.  */
+
+  int __first_nonopt;
+  int __last_nonopt;
+
+#if defined _LIBC && defined USE_NONOPTION_FLAGS
+  int __nonoption_flags_max_len;
+  int __nonoption_flags_len;
+# endif
+};
+
+/* The initializer is necessary to set OPTIND and OPTERR to their
+   default values and to clear the initialization flag.  */
+#define _GETOPT_DATA_INITIALIZER	{ 1, 1 }
+
+extern int _getopt_internal_r (int ___argc, char **___argv,
+			       const char *__shortopts,
+			       const struct option *__longopts, int *__longind,
+			       int __long_only, int __posixly_correct,
+			       struct _getopt_data *__data);
+
+extern int _getopt_long_r (int ___argc, char **___argv,
+			   const char *__shortopts,
+			   const struct option *__longopts, int *__longind,
+			   struct _getopt_data *__data);
+
+extern int _getopt_long_only_r (int ___argc, char **___argv,
+				const char *__shortopts,
+				const struct option *__longopts,
+				int *__longind,
+				struct _getopt_data *__data);
+
+#endif /* getopt_int.h */
diff --git a/src/bin/m4/lib/gettext.h b/src/bin/m4/lib/gettext.h
new file mode 100644
index 0000000000..18c62a4067
--- /dev/null
+++ b/src/bin/m4/lib/gettext.h
@@ -0,0 +1,269 @@
+/* Convenience header for conditional use of GNU <libintl.h>.
+   Copyright (C) 1995-1998, 2000-2002, 2004-2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _LIBGETTEXT_H
+#define _LIBGETTEXT_H 1
+
+/* NLS can be disabled through the configure --disable-nls option.  */
+#if ENABLE_NLS
+
+/* Get declarations of GNU message catalog functions.  */
+# include <libintl.h>
+
+/* You can set the DEFAULT_TEXT_DOMAIN macro to specify the domain used by
+   the gettext() and ngettext() macros.  This is an alternative to calling
+   textdomain(), and is useful for libraries.  */
+# ifdef DEFAULT_TEXT_DOMAIN
+#  undef gettext
+#  define gettext(Msgid) \
+     dgettext (DEFAULT_TEXT_DOMAIN, Msgid)
+#  undef ngettext
+#  define ngettext(Msgid1, Msgid2, N) \
+     dngettext (DEFAULT_TEXT_DOMAIN, Msgid1, Msgid2, N)
+# endif
+
+#else
+
+/* Solaris /usr/include/locale.h includes /usr/include/libintl.h, which
+   chokes if dcgettext is defined as a macro.  So include it now, to make
+   later inclusions of <locale.h> a NOP.  We don't include <libintl.h>
+   as well because people using "gettext.h" will not include <libintl.h>,
+   and also including <libintl.h> would fail on SunOS 4, whereas <locale.h>
+   is OK.  */
+#if defined(__sun)
+# include <locale.h>
+#endif
+
+/* Many header files from the libstdc++ coming with g++ 3.3 or newer include
+   <libintl.h>, which chokes if dcgettext is defined as a macro.  So include
+   it now, to make later inclusions of <libintl.h> a NOP.  */
+#if defined(__cplusplus) && defined(__GNUG__) && (__GNUC__ >= 3)
+# include <cstdlib>
+# if (__GLIBC__ >= 2) || _GLIBCXX_HAVE_LIBINTL_H
+#  include <libintl.h>
+# endif
+#endif
+
+/* Disabled NLS.
+   The casts to 'const char *' serve the purpose of producing warnings
+   for invalid uses of the value returned from these functions.
+   On pre-ANSI systems without 'const', the config.h file is supposed to
+   contain "#define const".  */
+# define gettext(Msgid) ((const char *) (Msgid))
+# define dgettext(Domainname, Msgid) ((void) (Domainname), gettext (Msgid))
+# define dcgettext(Domainname, Msgid, Category) \
+    ((void) (Category), dgettext (Domainname, Msgid))
+# define ngettext(Msgid1, Msgid2, N) \
+    ((N) == 1 \
+     ? ((void) (Msgid2), (const char *) (Msgid1)) \
+     : ((void) (Msgid1), (const char *) (Msgid2)))
+# define dngettext(Domainname, Msgid1, Msgid2, N) \
+    ((void) (Domainname), ngettext (Msgid1, Msgid2, N))
+# define dcngettext(Domainname, Msgid1, Msgid2, N, Category) \
+    ((void) (Category), dngettext(Domainname, Msgid1, Msgid2, N))
+# define textdomain(Domainname) ((const char *) (Domainname))
+# define bindtextdomain(Domainname, Dirname) \
+    ((void) (Domainname), (const char *) (Dirname))
+# define bind_textdomain_codeset(Domainname, Codeset) \
+    ((void) (Domainname), (const char *) (Codeset))
+
+#endif
+
+/* A pseudo function call that serves as a marker for the automated
+   extraction of messages, but does not call gettext().  The run-time
+   translation is done at a different place in the code.
+   The argument, String, should be a literal string.  Concatenated strings
+   and other string expressions won't work.
+   The macro's expansion is not parenthesized, so that it is suitable as
+   initializer for static 'char[]' or 'const char[]' variables.  */
+#define gettext_noop(String) String
+
+/* The separator between msgctxt and msgid in a .mo file.  */
+#define GETTEXT_CONTEXT_GLUE "\004"
+
+/* Pseudo function calls, taking a MSGCTXT and a MSGID instead of just a
+   MSGID.  MSGCTXT and MSGID must be string literals.  MSGCTXT should be
+   short and rarely need to change.
+   The letter 'p' stands for 'particular' or 'special'.  */
+#ifdef DEFAULT_TEXT_DOMAIN
+# define pgettext(Msgctxt, Msgid) \
+   pgettext_aux (DEFAULT_TEXT_DOMAIN, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, LC_MESSAGES)
+#else
+# define pgettext(Msgctxt, Msgid) \
+   pgettext_aux (NULL, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, LC_MESSAGES)
+#endif
+#define dpgettext(Domainname, Msgctxt, Msgid) \
+  pgettext_aux (Domainname, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, LC_MESSAGES)
+#define dcpgettext(Domainname, Msgctxt, Msgid, Category) \
+  pgettext_aux (Domainname, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, Category)
+#ifdef DEFAULT_TEXT_DOMAIN
+# define npgettext(Msgctxt, Msgid, MsgidPlural, N) \
+   npgettext_aux (DEFAULT_TEXT_DOMAIN, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, MsgidPlural, N, LC_MESSAGES)
+#else
+# define npgettext(Msgctxt, Msgid, MsgidPlural, N) \
+   npgettext_aux (NULL, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, MsgidPlural, N, LC_MESSAGES)
+#endif
+#define dnpgettext(Domainname, Msgctxt, Msgid, MsgidPlural, N) \
+  npgettext_aux (Domainname, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, MsgidPlural, N, LC_MESSAGES)
+#define dcnpgettext(Domainname, Msgctxt, Msgid, MsgidPlural, N, Category) \
+  npgettext_aux (Domainname, Msgctxt GETTEXT_CONTEXT_GLUE Msgid, Msgid, MsgidPlural, N, Category)
+
+#ifdef __GNUC__
+__inline
+#else
+#ifdef __cplusplus
+inline
+#endif
+#endif
+static const char *
+pgettext_aux (const char *domain,
+	      const char *msg_ctxt_id, const char *msgid,
+	      int category)
+{
+  const char *translation = dcgettext (domain, msg_ctxt_id, category);
+  if (translation == msg_ctxt_id)
+    return msgid;
+  else
+    return translation;
+}
+
+#ifdef __GNUC__
+__inline
+#else
+#ifdef __cplusplus
+inline
+#endif
+#endif
+static const char *
+npgettext_aux (const char *domain,
+	       const char *msg_ctxt_id, const char *msgid,
+	       const char *msgid_plural, unsigned long int n,
+	       int category)
+{
+  const char *translation =
+    dcngettext (domain, msg_ctxt_id, msgid_plural, n, category);
+  if (translation == msg_ctxt_id || translation == msgid_plural)
+    return (n == 1 ? msgid : msgid_plural);
+  else
+    return translation;
+}
+
+/* The same thing extended for non-constant arguments.  Here MSGCTXT and MSGID
+   can be arbitrary expressions.  But for string literals these macros are
+   less efficient than those above.  */
+
+#include <string.h>
+
+#define _LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS \
+  (__GNUC__ >= 3 || __GNUG__ >= 2 /* || __STDC_VERSION__ >= 199901L */ )
+
+#if !_LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS
+#include <stdlib.h>
+#endif
+
+#define pgettext_expr(Msgctxt, Msgid) \
+  dcpgettext_expr (NULL, Msgctxt, Msgid, LC_MESSAGES)
+#define dpgettext_expr(Domainname, Msgctxt, Msgid) \
+  dcpgettext_expr (Domainname, Msgctxt, Msgid, LC_MESSAGES)
+
+#ifdef __GNUC__
+__inline
+#else
+#ifdef __cplusplus
+inline
+#endif
+#endif
+static const char *
+dcpgettext_expr (const char *domain,
+		 const char *msgctxt, const char *msgid,
+		 int category)
+{
+  size_t msgctxt_len = strlen (msgctxt) + 1;
+  size_t msgid_len = strlen (msgid) + 1;
+  const char *translation;
+#if _LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS
+  char msg_ctxt_id[msgctxt_len + msgid_len];
+#else
+  char buf[1024];
+  char *msg_ctxt_id =
+    (msgctxt_len + msgid_len <= sizeof (buf)
+     ? buf
+     : (char *) malloc (msgctxt_len + msgid_len));
+  if (msg_ctxt_id != NULL)
+#endif
+    {
+      memcpy (msg_ctxt_id, msgctxt, msgctxt_len - 1);
+      msg_ctxt_id[msgctxt_len - 1] = '\004';
+      memcpy (msg_ctxt_id + msgctxt_len, msgid, msgid_len);
+      translation = dcgettext (domain, msg_ctxt_id, category);
+#if !_LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS
+      if (msg_ctxt_id != buf)
+	free (msg_ctxt_id);
+#endif
+      if (translation != msg_ctxt_id)
+	return translation;
+    }
+  return msgid;
+}
+
+#define npgettext_expr(Msgctxt, Msgid, MsgidPlural, N) \
+  dcnpgettext_expr (NULL, Msgctxt, Msgid, MsgidPlural, N, LC_MESSAGES)
+#define dnpgettext_expr(Domainname, Msgctxt, Msgid, MsgidPlural, N) \
+  dcnpgettext_expr (Domainname, Msgctxt, Msgid, MsgidPlural, N, LC_MESSAGES)
+
+#ifdef __GNUC__
+__inline
+#else
+#ifdef __cplusplus
+inline
+#endif
+#endif
+static const char *
+dcnpgettext_expr (const char *domain,
+		  const char *msgctxt, const char *msgid,
+		  const char *msgid_plural, unsigned long int n,
+		  int category)
+{
+  size_t msgctxt_len = strlen (msgctxt) + 1;
+  size_t msgid_len = strlen (msgid) + 1;
+  const char *translation;
+#if _LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS
+  char msg_ctxt_id[msgctxt_len + msgid_len];
+#else
+  char buf[1024];
+  char *msg_ctxt_id =
+    (msgctxt_len + msgid_len <= sizeof (buf)
+     ? buf
+     : (char *) malloc (msgctxt_len + msgid_len));
+  if (msg_ctxt_id != NULL)
+#endif
+    {
+      memcpy (msg_ctxt_id, msgctxt, msgctxt_len - 1);
+      msg_ctxt_id[msgctxt_len - 1] = '\004';
+      memcpy (msg_ctxt_id + msgctxt_len, msgid, msgid_len);
+      translation = dcngettext (domain, msg_ctxt_id, msgid_plural, n, category);
+#if !_LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS
+      if (msg_ctxt_id != buf)
+	free (msg_ctxt_id);
+#endif
+      if (!(translation == msg_ctxt_id || translation == msgid_plural))
+	return translation;
+    }
+  return (n == 1 ? msgid : msgid_plural);
+}
+
+#endif /* _LIBGETTEXT_H */
diff --git a/src/bin/m4/lib/gl_anyhash_list1.h b/src/bin/m4/lib/gl_anyhash_list1.h
new file mode 100644
index 0000000000..1f1351e7ac
--- /dev/null
+++ b/src/bin/m4/lib/gl_anyhash_list1.h
@@ -0,0 +1,28 @@
+/* Sequential list data type implemented by a hash table with another list.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Common code of
+   gl_linkedhash_list.c, gl_avltreehash_list.c, gl_rbtreehash_list.c.  */
+
+/* Hash table entry.  */
+struct gl_hash_entry
+{
+  struct gl_hash_entry *hash_next;  /* chain of entries in same bucket */
+  size_t hashcode;                  /* cache of values' common hash code */
+};
+typedef struct gl_hash_entry * gl_hash_entry_t;
diff --git a/src/bin/m4/lib/gl_anyhash_list2.h b/src/bin/m4/lib/gl_anyhash_list2.h
new file mode 100644
index 0000000000..d719116866
--- /dev/null
+++ b/src/bin/m4/lib/gl_anyhash_list2.h
@@ -0,0 +1,127 @@
+/* Sequential list data type implemented by a hash table with another list.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Common code of
+   gl_linkedhash_list.c, gl_avltreehash_list.c, gl_rbtreehash_list.c.  */
+
+/* Array of primes, approximately in steps of factor 1.2.
+   This table was computed by executing the Common Lisp expression
+     (dotimes (i 244) (format t "nextprime(~D)~%" (ceiling (expt 1.2d0 i))))
+   and feeding the result to PARI/gp.  */
+static const size_t primes[] =
+  {
+    11, 13, 17, 19, 23, 29, 37, 41, 47, 59, 67, 83, 97, 127, 139, 167, 199,
+    239, 293, 347, 419, 499, 593, 709, 853, 1021, 1229, 1471, 1777, 2129, 2543,
+    3049, 3659, 4391, 5273, 6323, 7589, 9103, 10937, 13109, 15727, 18899,
+    22651, 27179, 32609, 39133, 46957, 56359, 67619, 81157, 97369, 116849,
+    140221, 168253, 201907, 242309, 290761, 348889, 418667, 502409, 602887,
+    723467, 868151, 1041779, 1250141, 1500181, 1800191, 2160233, 2592277,
+    3110741, 3732887, 4479463, 5375371, 6450413, 7740517, 9288589, 11146307,
+    13375573, 16050689, 19260817, 23112977, 27735583, 33282701, 39939233,
+    47927081, 57512503, 69014987, 82818011, 99381577, 119257891, 143109469,
+    171731387, 206077643, 247293161, 296751781, 356102141, 427322587,
+    512787097, 615344489, 738413383, 886096061, 1063315271, 1275978331,
+    1531174013, 1837408799, 2204890543UL, 2645868653UL, 3175042391UL,
+    3810050851UL,
+#if SIZE_MAX > 4294967295UL
+    4572061027UL, 5486473229UL, 6583767889UL, 7900521449UL, 9480625733UL,
+    11376750877UL, 13652101063UL, 16382521261UL, 19659025513UL, 23590830631UL,
+    28308996763UL, 33970796089UL, 40764955463UL, 48917946377UL, 58701535657UL,
+    70441842749UL, 84530211301UL, 101436253561UL, 121723504277UL,
+    146068205131UL, 175281846149UL, 210338215379UL, 252405858521UL,
+    302887030151UL, 363464436191UL, 436157323417UL, 523388788231UL,
+    628066545713UL, 753679854847UL, 904415825857UL, 1085298991109UL,
+    1302358789181UL, 1562830547009UL, 1875396656429UL, 2250475987709UL,
+    2700571185239UL, 3240685422287UL, 3888822506759UL, 4666587008147UL,
+    5599904409713UL, 6719885291641UL, 8063862349969UL, 9676634819959UL,
+    11611961783951UL, 13934354140769UL, 16721224968907UL, 20065469962669UL,
+    24078563955191UL, 28894276746229UL, 34673132095507UL, 41607758514593UL,
+    49929310217531UL, 59915172260971UL, 71898206713183UL, 86277848055823UL,
+    103533417666967UL, 124240101200359UL, 149088121440451UL, 178905745728529UL,
+    214686894874223UL, 257624273849081UL, 309149128618903UL, 370978954342639UL,
+    445174745211143UL, 534209694253381UL, 641051633104063UL, 769261959724877UL,
+    923114351670013UL, 1107737222003791UL, 1329284666404567UL,
+    1595141599685509UL, 1914169919622551UL, 2297003903547091UL,
+    2756404684256459UL, 3307685621107757UL, 3969222745329323UL,
+    4763067294395177UL, 5715680753274209UL, 6858816903929113UL,
+    8230580284714831UL, 9876696341657791UL, 11852035609989371UL,
+    14222442731987227UL, 17066931278384657UL, 20480317534061597UL,
+    24576381040873903UL, 29491657249048679UL, 35389988698858471UL,
+    42467986438630267UL, 50961583726356109UL, 61153900471627387UL,
+    73384680565952851UL, 88061616679143347UL, 105673940014972061UL,
+    126808728017966413UL, 152170473621559703UL, 182604568345871671UL,
+    219125482015045997UL, 262950578418055169UL, 315540694101666193UL,
+    378648832921999397UL, 454378599506399233UL, 545254319407679131UL,
+    654305183289214771UL, 785166219947057701UL, 942199463936469157UL,
+    1130639356723763129UL, 1356767228068515623UL, 1628120673682218619UL,
+    1953744808418662409UL, 2344493770102394881UL, 2813392524122873857UL,
+    3376071028947448339UL, 4051285234736937517UL, 4861542281684325481UL,
+    5833850738021191727UL, 7000620885625427969UL, 8400745062750513217UL,
+    10080894075300616261UL, 12097072890360739951UL, 14516487468432885797UL,
+    17419784962119465179UL,
+#endif
+    SIZE_MAX /* sentinel, to ensure the search terminates */
+  };
+
+/* Return a suitable prime >= ESTIMATE.  */
+static size_t
+next_prime (size_t estimate)
+{
+  size_t i;
+
+  for (i = 0; i < sizeof (primes) / sizeof (primes[0]); i++)
+    if (primes[i] >= estimate)
+      return primes[i];
+  return SIZE_MAX; /* not a prime, but better than nothing */
+}
+
+/* Resize the hash table with a new estimated size.  */
+static void
+hash_resize (gl_list_t list, size_t estimate)
+{
+  size_t new_size = next_prime (estimate);
+
+  if (new_size > list->table_size)
+    {
+      gl_hash_entry_t *old_table = list->table;
+      /* Allocate the new table.  */
+      gl_hash_entry_t *new_table = XCALLOC (new_size, gl_hash_entry_t);
+      size_t i;
+
+      /* Iterate through the entries of the old table.  */
+      for (i = list->table_size; i > 0; )
+	{
+	  gl_hash_entry_t node = old_table[--i];
+
+	  while (node != NULL)
+	    {
+	      gl_hash_entry_t next = node->hash_next;
+	      /* Add the entry to the new table.  */
+	      size_t bucket = node->hashcode % new_size;
+	      node->hash_next = new_table[bucket];
+	      new_table[bucket] = node;
+
+	      node = next;
+	    }
+	}
+
+      list->table = new_table;
+      list->table_size = new_size;
+      free (old_table);
+    }
+}
diff --git a/src/bin/m4/lib/gl_anylinked_list1.h b/src/bin/m4/lib/gl_anylinked_list1.h
new file mode 100644
index 0000000000..988657e5c4
--- /dev/null
+++ b/src/bin/m4/lib/gl_anylinked_list1.h
@@ -0,0 +1,49 @@
+/* Sequential list data type implemented by a linked list.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Common code of gl_linked_list.c and gl_linkedhash_list.c.  */
+
+/* -------------------------- gl_list_t Data Type -------------------------- */
+
+/* Concrete list node implementation, valid for this file only.  */
+struct gl_list_node_impl
+{
+#if WITH_HASHTABLE
+  struct gl_hash_entry h;           /* hash table entry fields; must be first */
+#endif
+  struct gl_list_node_impl *next;
+  struct gl_list_node_impl *prev;
+  const void *value;
+};
+
+/* Concrete gl_list_impl type, valid for this file only.  */
+struct gl_list_impl
+{
+  struct gl_list_impl_base base;
+#if WITH_HASHTABLE
+  /* A hash table: managed as an array of collision lists.  */
+  struct gl_hash_entry **table;
+  size_t table_size;
+#endif
+  /* A circular list anchored at root.
+     The first node is = root.next, the last node is = root.prev.
+     The root's value is unused.  */
+  struct gl_list_node_impl root;
+  /* Number of list nodes, excluding the root.  */
+  size_t count;
+};
diff --git a/src/bin/m4/lib/gl_anylinked_list2.h b/src/bin/m4/lib/gl_anylinked_list2.h
new file mode 100644
index 0000000000..718dfb713a
--- /dev/null
+++ b/src/bin/m4/lib/gl_anylinked_list2.h
@@ -0,0 +1,1045 @@
+/* Sequential list data type implemented by a linked list.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Common code of gl_linked_list.c and gl_linkedhash_list.c.  */
+
+/* If the symbol SIGNAL_SAFE_LIST is defined, the code is compiled in such
+   a way that a gl_list_t data structure may be used from within a signal
+   handler.  The operations allowed in the signal handler are:
+     gl_list_iterator, gl_list_iterator_next, gl_list_iterator_free.
+   The list and node fields that are therefore accessed from the signal handler
+   are:
+     list->root, node->next, node->value.
+   We are careful to make modifications to these fields only in an order
+   that maintains the consistency of the list data structure at any moment,
+   and we use 'volatile' assignments to prevent the compiler from reordering
+   such assignments.  */
+#ifdef SIGNAL_SAFE_LIST
+# define ASYNCSAFE(type) *(volatile type *)&
+#else
+# define ASYNCSAFE(type)
+#endif
+
+/* -------------------------- gl_list_t Data Type -------------------------- */
+
+static gl_list_t
+gl_linked_create_empty (gl_list_implementation_t implementation,
+			gl_listelement_equals_fn equals_fn,
+			gl_listelement_hashcode_fn hashcode_fn,
+			bool allow_duplicates)
+{
+  struct gl_list_impl *list = XMALLOC (struct gl_list_impl);
+
+  list->base.vtable = implementation;
+  list->base.equals_fn = equals_fn;
+  list->base.hashcode_fn = hashcode_fn;
+  list->base.allow_duplicates = allow_duplicates;
+#if WITH_HASHTABLE
+  list->table_size = 11;
+  list->table = XCALLOC (list->table_size, gl_hash_entry_t);
+#endif
+  list->root.next = &list->root;
+  list->root.prev = &list->root;
+  list->count = 0;
+
+  return list;
+}
+
+static gl_list_t
+gl_linked_create (gl_list_implementation_t implementation,
+		  gl_listelement_equals_fn equals_fn,
+		  gl_listelement_hashcode_fn hashcode_fn,
+		  bool allow_duplicates,
+		  size_t count, const void **contents)
+{
+  struct gl_list_impl *list = XMALLOC (struct gl_list_impl);
+  gl_list_node_t tail;
+
+  list->base.vtable = implementation;
+  list->base.equals_fn = equals_fn;
+  list->base.hashcode_fn = hashcode_fn;
+  list->base.allow_duplicates = allow_duplicates;
+#if WITH_HASHTABLE
+  {
+    size_t estimate = xsum (count, count / 2); /* 1.5 * count */
+    if (estimate < 10)
+      estimate = 10;
+    list->table_size = next_prime (estimate);
+    list->table = XCALLOC (list->table_size, gl_hash_entry_t);
+  }
+#endif
+  list->count = count;
+  tail = &list->root;
+  for (; count > 0; contents++, count--)
+    {
+      gl_list_node_t node = XMALLOC (struct gl_list_node_impl);
+
+      node->value = *contents;
+#if WITH_HASHTABLE
+      node->h.hashcode =
+	(list->base.hashcode_fn != NULL
+	 ? list->base.hashcode_fn (node->value)
+	 : (size_t)(uintptr_t) node->value);
+
+      /* Add node to the hash table.  */
+      add_to_bucket (list, node);
+#endif
+
+      /* Add node to the list.  */
+      node->prev = tail;
+      tail->next = node;
+      tail = node;
+    }
+  tail->next = &list->root;
+  list->root.prev = tail;
+
+  return list;
+}
+
+static size_t
+gl_linked_size (gl_list_t list)
+{
+  return list->count;
+}
+
+static const void *
+gl_linked_node_value (gl_list_t list, gl_list_node_t node)
+{
+  return node->value;
+}
+
+static gl_list_node_t
+gl_linked_next_node (gl_list_t list, gl_list_node_t node)
+{
+  return (node->next != &list->root ? node->next : NULL);
+}
+
+static gl_list_node_t
+gl_linked_previous_node (gl_list_t list, gl_list_node_t node)
+{
+  return (node->prev != &list->root ? node->prev : NULL);
+}
+
+static const void *
+gl_linked_get_at (gl_list_t list, size_t position)
+{
+  size_t count = list->count;
+  gl_list_node_t node;
+
+  if (!(position < count))
+    /* Invalid argument.  */
+    abort ();
+  /* Here we know count > 0.  */
+  if (position <= ((count - 1) / 2))
+    {
+      node = list->root.next;
+      for (; position > 0; position--)
+	node = node->next;
+    }
+  else
+    {
+      position = count - 1 - position;
+      node = list->root.prev;
+      for (; position > 0; position--)
+	node = node->prev;
+    }
+  return node->value;
+}
+
+static gl_list_node_t
+gl_linked_set_at (gl_list_t list, size_t position, const void *elt)
+{
+  size_t count = list->count;
+  gl_list_node_t node;
+
+  if (!(position < count))
+    /* Invalid argument.  */
+    abort ();
+  /* Here we know count > 0.  */
+  if (position <= ((count - 1) / 2))
+    {
+      node = list->root.next;
+      for (; position > 0; position--)
+	node = node->next;
+    }
+  else
+    {
+      position = count - 1 - position;
+      node = list->root.prev;
+      for (; position > 0; position--)
+	node = node->prev;
+    }
+#if WITH_HASHTABLE
+  if (elt != node->value)
+    {
+      size_t new_hashcode =
+	(list->base.hashcode_fn != NULL
+	 ? list->base.hashcode_fn (elt)
+	 : (size_t)(uintptr_t) elt);
+
+      if (new_hashcode != node->h.hashcode)
+	{
+	  remove_from_bucket (list, node);
+	  node->value = elt;
+	  node->h.hashcode = new_hashcode;
+	  add_to_bucket (list, node);
+	}
+      else
+	node->value = elt;
+    }
+#else
+  node->value = elt;
+#endif
+  return node;
+}
+
+static gl_list_node_t
+gl_linked_search_from_to (gl_list_t list, size_t start_index, size_t end_index,
+			  const void *elt)
+{
+  size_t count = list->count;
+
+  if (!(start_index <= end_index && end_index <= count))
+    /* Invalid arguments.  */
+    abort ();
+  {
+#if WITH_HASHTABLE
+    size_t hashcode =
+      (list->base.hashcode_fn != NULL
+       ? list->base.hashcode_fn (elt)
+       : (size_t)(uintptr_t) elt);
+    size_t bucket = hashcode % list->table_size;
+    gl_listelement_equals_fn equals = list->base.equals_fn;
+
+    if (!list->base.allow_duplicates)
+      {
+	/* Look for the first match in the hash bucket.  */
+	gl_list_node_t found = NULL;
+	gl_list_node_t node;
+
+	for (node = (gl_list_node_t) list->table[bucket];
+	     node != NULL;
+	     node = (gl_list_node_t) node->h.hash_next)
+	  if (node->h.hashcode == hashcode
+	      && (equals != NULL
+		  ? equals (elt, node->value)
+		  : elt == node->value))
+	    {
+	      found = node;
+	      break;
+	    }
+	if (start_index > 0)
+	  /* Look whether found's index is < start_index.  */
+	  for (node = list->root.next; ; node = node->next)
+	    {
+	      if (node == found)
+		return NULL;
+	      if (--start_index == 0)
+		break;
+	    }
+	if (end_index < count)
+	  /* Look whether found's index is >= end_index.  */
+	  {
+	    end_index = count - end_index;
+	    for (node = list->root.prev; ; node = node->prev)
+	      {
+		if (node == found)
+		  return NULL;
+		if (--end_index == 0)
+		  break;
+	      }
+	  }
+	return found;
+      }
+    else
+      {
+	/* Look whether there is more than one match in the hash bucket.  */
+	bool multiple_matches = false;
+	gl_list_node_t first_match = NULL;
+	gl_list_node_t node;
+
+	for (node = (gl_list_node_t) list->table[bucket];
+	     node != NULL;
+	     node = (gl_list_node_t) node->h.hash_next)
+	  if (node->h.hashcode == hashcode
+	      && (equals != NULL
+		  ? equals (elt, node->value)
+		  : elt == node->value))
+	    {
+	      if (first_match == NULL)
+		first_match = node;
+	      else
+		{
+		  multiple_matches = true;
+		  break;
+		}
+	    }
+	if (multiple_matches)
+	  {
+	    /* We need the match with the smallest index.  But we don't have
+	       a fast mapping node -> index.  So we have to walk the list.  */
+	    end_index -= start_index;
+	    node = list->root.next;
+	    for (; start_index > 0; start_index--)
+	      node = node->next;
+
+	    for (;
+		 end_index > 0;
+		 node = node->next, end_index--)
+	      if (node->h.hashcode == hashcode
+		  && (equals != NULL
+		      ? equals (elt, node->value)
+		      : elt == node->value))
+		return node;
+	    /* The matches must have all been at indices < start_index or
+	       >= end_index.  */
+	    return NULL;
+	  }
+	else
+	  {
+	    if (start_index > 0)
+	      /* Look whether first_match's index is < start_index.  */
+	      for (node = list->root.next; node != &list->root; node = node->next)
+		{
+		  if (node == first_match)
+		    return NULL;
+		  if (--start_index == 0)
+		    break;
+		}
+	    if (end_index < list->count)
+	      /* Look whether first_match's index is >= end_index.  */
+	      {
+		end_index = list->count - end_index;
+		for (node = list->root.prev; ; node = node->prev)
+		  {
+		    if (node == first_match)
+		      return NULL;
+		    if (--end_index == 0)
+		      break;
+		  }
+	      }
+	    return first_match;
+	  }
+      }
+#else
+    gl_listelement_equals_fn equals = list->base.equals_fn;
+    gl_list_node_t node = list->root.next;
+
+    end_index -= start_index;
+    for (; start_index > 0; start_index--)
+      node = node->next;
+
+    if (equals != NULL)
+      {
+	for (; end_index > 0; node = node->next, end_index--)
+	  if (equals (elt, node->value))
+	    return node;
+      }
+    else
+      {
+	for (; end_index > 0; node = node->next, end_index--)
+	  if (elt == node->value)
+	    return node;
+      }
+    return NULL;
+#endif
+  }
+}
+
+static size_t
+gl_linked_indexof_from_to (gl_list_t list, size_t start_index, size_t end_index,
+			   const void *elt)
+{
+  size_t count = list->count;
+
+  if (!(start_index <= end_index && end_index <= count))
+    /* Invalid arguments.  */
+    abort ();
+  {
+#if WITH_HASHTABLE
+    /* Here the hash table doesn't help much.  It only allows us to minimize
+       the number of equals() calls, by looking up first the node and then
+       its index.  */
+    size_t hashcode =
+      (list->base.hashcode_fn != NULL
+       ? list->base.hashcode_fn (elt)
+       : (size_t)(uintptr_t) elt);
+    size_t bucket = hashcode % list->table_size;
+    gl_listelement_equals_fn equals = list->base.equals_fn;
+    gl_list_node_t node;
+
+    /* First step: Look up the node.  */
+    if (!list->base.allow_duplicates)
+      {
+	/* Look for the first match in the hash bucket.  */
+	for (node = (gl_list_node_t) list->table[bucket];
+	     node != NULL;
+	     node = (gl_list_node_t) node->h.hash_next)
+	  if (node->h.hashcode == hashcode
+	      && (equals != NULL
+		  ? equals (elt, node->value)
+		  : elt == node->value))
+	    break;
+      }
+    else
+      {
+	/* Look whether there is more than one match in the hash bucket.  */
+	bool multiple_matches = false;
+	gl_list_node_t first_match = NULL;
+
+	for (node = (gl_list_node_t) list->table[bucket];
+	     node != NULL;
+	     node = (gl_list_node_t) node->h.hash_next)
+	  if (node->h.hashcode == hashcode
+	      && (equals != NULL
+		  ? equals (elt, node->value)
+		  : elt == node->value))
+	    {
+	      if (first_match == NULL)
+		first_match = node;
+	      else
+		{
+		  multiple_matches = true;
+		  break;
+		}
+	    }
+	if (multiple_matches)
+	  {
+	    /* We need the match with the smallest index.  But we don't have
+	       a fast mapping node -> index.  So we have to walk the list.  */
+	    size_t index;
+
+	    index = start_index;
+	    node = list->root.next;
+	    for (; start_index > 0; start_index--)
+	      node = node->next;
+
+	    for (;
+		 index < end_index;
+		 node = node->next, index++)
+	      if (node->h.hashcode == hashcode
+		  && (equals != NULL
+		      ? equals (elt, node->value)
+		      : elt == node->value))
+		return index;
+	    /* The matches must have all been at indices < start_index or
+	       >= end_index.  */
+	    return (size_t)(-1);
+	  }
+	node = first_match;
+      }
+
+    /* Second step: Look up the index of the node.  */
+    if (node == NULL)
+      return (size_t)(-1);
+    else
+      {
+	size_t index = 0;
+
+	for (; node->prev != &list->root; node = node->prev)
+	  index++;
+
+	if (index >= start_index && index < end_index)
+	  return index;
+	else
+	  return (size_t)(-1);
+      }
+#else
+    gl_listelement_equals_fn equals = list->base.equals_fn;
+    size_t index = start_index;
+    gl_list_node_t node = list->root.next;
+
+    for (; start_index > 0; start_index--)
+      node = node->next;
+
+    if (equals != NULL)
+      {
+	for (;
+	     index < end_index;
+	     node = node->next, index++)
+	  if (equals (elt, node->value))
+	    return index;
+      }
+    else
+      {
+	for (;
+	     index < end_index;
+	     node = node->next, index++)
+	  if (elt == node->value)
+	    return index;
+      }
+    return (size_t)(-1);
+#endif
+  }
+}
+
+static gl_list_node_t
+gl_linked_add_first (gl_list_t list, const void *elt)
+{
+  gl_list_node_t node = XMALLOC (struct gl_list_node_impl);
+
+  ASYNCSAFE(const void *) node->value = elt;
+#if WITH_HASHTABLE
+  node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (node->value)
+     : (size_t)(uintptr_t) node->value);
+
+  /* Add node to the hash table.  */
+  add_to_bucket (list, node);
+#endif
+
+  /* Add node to the list.  */
+  node->prev = &list->root;
+  ASYNCSAFE(gl_list_node_t) node->next = list->root.next;
+  node->next->prev = node;
+  ASYNCSAFE(gl_list_node_t) list->root.next = node;
+  list->count++;
+
+#if WITH_HASHTABLE
+  hash_resize_after_add (list);
+#endif
+
+  return node;
+}
+
+static gl_list_node_t
+gl_linked_add_last (gl_list_t list, const void *elt)
+{
+  gl_list_node_t node = XMALLOC (struct gl_list_node_impl);
+
+  ASYNCSAFE(const void *) node->value = elt;
+#if WITH_HASHTABLE
+  node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (node->value)
+     : (size_t)(uintptr_t) node->value);
+
+  /* Add node to the hash table.  */
+  add_to_bucket (list, node);
+#endif
+
+  /* Add node to the list.  */
+  ASYNCSAFE(gl_list_node_t) node->next = &list->root;
+  node->prev = list->root.prev;
+  ASYNCSAFE(gl_list_node_t) node->prev->next = node;
+  list->root.prev = node;
+  list->count++;
+
+#if WITH_HASHTABLE
+  hash_resize_after_add (list);
+#endif
+
+  return node;
+}
+
+static gl_list_node_t
+gl_linked_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  gl_list_node_t new_node = XMALLOC (struct gl_list_node_impl);
+
+  ASYNCSAFE(const void *) new_node->value = elt;
+#if WITH_HASHTABLE
+  new_node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (new_node->value)
+     : (size_t)(uintptr_t) new_node->value);
+
+  /* Add new_node to the hash table.  */
+  add_to_bucket (list, new_node);
+#endif
+
+  /* Add new_node to the list.  */
+  ASYNCSAFE(gl_list_node_t) new_node->next = node;
+  new_node->prev = node->prev;
+  ASYNCSAFE(gl_list_node_t) new_node->prev->next = new_node;
+  node->prev = new_node;
+  list->count++;
+
+#if WITH_HASHTABLE
+  hash_resize_after_add (list);
+#endif
+
+  return new_node;
+}
+
+static gl_list_node_t
+gl_linked_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  gl_list_node_t new_node = XMALLOC (struct gl_list_node_impl);
+
+  ASYNCSAFE(const void *) new_node->value = elt;
+#if WITH_HASHTABLE
+  new_node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (new_node->value)
+     : (size_t)(uintptr_t) new_node->value);
+
+  /* Add new_node to the hash table.  */
+  add_to_bucket (list, new_node);
+#endif
+
+  /* Add new_node to the list.  */
+  new_node->prev = node;
+  ASYNCSAFE(gl_list_node_t) new_node->next = node->next;
+  new_node->next->prev = new_node;
+  ASYNCSAFE(gl_list_node_t) node->next = new_node;
+  list->count++;
+
+#if WITH_HASHTABLE
+  hash_resize_after_add (list);
+#endif
+
+  return new_node;
+}
+
+static gl_list_node_t
+gl_linked_add_at (gl_list_t list, size_t position, const void *elt)
+{
+  size_t count = list->count;
+  gl_list_node_t new_node;
+
+  if (!(position <= count))
+    /* Invalid argument.  */
+    abort ();
+
+  new_node = XMALLOC (struct gl_list_node_impl);
+  ASYNCSAFE(const void *) new_node->value = elt;
+#if WITH_HASHTABLE
+  new_node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (new_node->value)
+     : (size_t)(uintptr_t) new_node->value);
+
+  /* Add new_node to the hash table.  */
+  add_to_bucket (list, new_node);
+#endif
+
+  /* Add new_node to the list.  */
+  if (position <= (count / 2))
+    {
+      gl_list_node_t node;
+
+      node = &list->root;
+      for (; position > 0; position--)
+	node = node->next;
+      new_node->prev = node;
+      ASYNCSAFE(gl_list_node_t) new_node->next = node->next;
+      new_node->next->prev = new_node;
+      ASYNCSAFE(gl_list_node_t) node->next = new_node;
+    }
+  else
+    {
+      gl_list_node_t node;
+
+      position = count - position;
+      node = &list->root;
+      for (; position > 0; position--)
+	node = node->prev;
+      ASYNCSAFE(gl_list_node_t) new_node->next = node;
+      new_node->prev = node->prev;
+      ASYNCSAFE(gl_list_node_t) new_node->prev->next = new_node;
+      node->prev = new_node;
+    }
+  list->count++;
+
+#if WITH_HASHTABLE
+  hash_resize_after_add (list);
+#endif
+
+  return new_node;
+}
+
+static bool
+gl_linked_remove_node (gl_list_t list, gl_list_node_t node)
+{
+  gl_list_node_t prev;
+  gl_list_node_t next;
+
+#if WITH_HASHTABLE
+  /* Remove node from the hash table.  */
+  remove_from_bucket (list, node);
+#endif
+
+  /* Remove node from the list.  */
+  prev = node->prev;
+  next = node->next;
+
+  ASYNCSAFE(gl_list_node_t) prev->next = next;
+  next->prev = prev;
+  list->count--;
+
+  free (node);
+  return true;
+}
+
+static bool
+gl_linked_remove_at (gl_list_t list, size_t position)
+{
+  size_t count = list->count;
+  gl_list_node_t removed_node;
+
+  if (!(position < count))
+    /* Invalid argument.  */
+    abort ();
+  /* Here we know count > 0.  */
+  if (position <= ((count - 1) / 2))
+    {
+      gl_list_node_t node;
+      gl_list_node_t after_removed;
+
+      node = &list->root;
+      for (; position > 0; position--)
+	node = node->next;
+      removed_node = node->next;
+      after_removed = node->next->next;
+      ASYNCSAFE(gl_list_node_t) node->next = after_removed;
+      after_removed->prev = node;
+    }
+  else
+    {
+      gl_list_node_t node;
+      gl_list_node_t before_removed;
+
+      position = count - 1 - position;
+      node = &list->root;
+      for (; position > 0; position--)
+	node = node->prev;
+      removed_node = node->prev;
+      before_removed = node->prev->prev;
+      node->prev = before_removed;
+      ASYNCSAFE(gl_list_node_t) before_removed->next = node;
+    }
+#if WITH_HASHTABLE
+  remove_from_bucket (list, removed_node);
+#endif
+  list->count--;
+
+  free (removed_node);
+  return true;
+}
+
+static bool
+gl_linked_remove (gl_list_t list, const void *elt)
+{
+  gl_list_node_t node = gl_linked_search_from_to (list, 0, list->count, elt);
+
+  if (node != NULL)
+    return gl_linked_remove_node (list, node);
+  else
+    return false;
+}
+
+static void
+gl_linked_list_free (gl_list_t list)
+{
+  gl_list_node_t node;
+
+  for (node = list->root.next; node != &list->root; )
+    {
+      gl_list_node_t next = node->next;
+      free (node);
+      node = next;
+    }
+#if WITH_HASHTABLE
+  free (list->table);
+#endif
+  free (list);
+}
+
+/* --------------------- gl_list_iterator_t Data Type --------------------- */
+
+static gl_list_iterator_t
+gl_linked_iterator (gl_list_t list)
+{
+  gl_list_iterator_t result;
+
+  result.vtable = list->base.vtable;
+  result.list = list;
+  result.p = list->root.next;
+  result.q = &list->root;
+#ifdef lint
+  result.i = 0;
+  result.j = 0;
+  result.count = 0;
+#endif
+
+  return result;
+}
+
+static gl_list_iterator_t
+gl_linked_iterator_from_to (gl_list_t list,
+			    size_t start_index, size_t end_index)
+{
+  gl_list_iterator_t result;
+  size_t n1, n2, n3;
+
+  if (!(start_index <= end_index && end_index <= list->count))
+    /* Invalid arguments.  */
+    abort ();
+  result.vtable = list->base.vtable;
+  result.list = list;
+  n1 = start_index;
+  n2 = end_index - start_index;
+  n3 = list->count - end_index;
+  /* Find the maximum among n1, n2, n3, so as to reduce the number of
+     loop iterations to n1 + n2 + n3 - max(n1,n2,n3).  */
+  if (n1 > n2 && n1 > n3)
+    {
+      /* n1 is the maximum, use n2 and n3.  */
+      gl_list_node_t node;
+      size_t i;
+
+      node = &list->root;
+      for (i = n3; i > 0; i--)
+	node = node->prev;
+      result.q = node;
+      for (i = n2; i > 0; i--)
+	node = node->prev;
+      result.p = node;
+    }
+  else if (n2 > n3)
+    {
+      /* n2 is the maximum, use n1 and n3.  */
+      gl_list_node_t node;
+      size_t i;
+
+      node = list->root.next;
+      for (i = n1; i > 0; i--)
+	node = node->next;
+      result.p = node;
+
+      node = &list->root;
+      for (i = n3; i > 0; i--)
+	node = node->prev;
+      result.q = node;
+    }
+  else
+    {
+      /* n3 is the maximum, use n1 and n2.  */
+      gl_list_node_t node;
+      size_t i;
+
+      node = list->root.next;
+      for (i = n1; i > 0; i--)
+	node = node->next;
+      result.p = node;
+      for (i = n2; i > 0; i--)
+	node = node->next;
+      result.q = node;
+    }
+
+#ifdef lint
+  result.i = 0;
+  result.j = 0;
+  result.count = 0;
+#endif
+
+  return result;
+}
+
+static bool
+gl_linked_iterator_next (gl_list_iterator_t *iterator,
+			 const void **eltp, gl_list_node_t *nodep)
+{
+  if (iterator->p != iterator->q)
+    {
+      gl_list_node_t node = (gl_list_node_t) iterator->p;
+      *eltp = node->value;
+      if (nodep != NULL)
+	*nodep = node;
+      iterator->p = node->next;
+      return true;
+    }
+  else
+    return false;
+}
+
+static void
+gl_linked_iterator_free (gl_list_iterator_t *iterator)
+{
+}
+
+/* ---------------------- Sorted gl_list_t Data Type ---------------------- */
+
+static gl_list_node_t
+gl_linked_sortedlist_search (gl_list_t list, gl_listelement_compar_fn compar,
+			     const void *elt)
+{
+  gl_list_node_t node;
+
+  for (node = list->root.next; node != &list->root; node = node->next)
+    {
+      int cmp = compar (node->value, elt);
+
+      if (cmp > 0)
+	break;
+      if (cmp == 0)
+	return node;
+    }
+  return NULL;
+}
+
+static gl_list_node_t
+gl_linked_sortedlist_search_from_to (gl_list_t list,
+				     gl_listelement_compar_fn compar,
+				     size_t low, size_t high,
+				     const void *elt)
+{
+  size_t count = list->count;
+
+  if (!(low <= high && high <= list->count))
+    /* Invalid arguments.  */
+    abort ();
+
+  high -= low;
+  if (high > 0)
+    {
+      /* Here we know low < count.  */
+      size_t position = low;
+      gl_list_node_t node;
+
+      if (position <= ((count - 1) / 2))
+	{
+	  node = list->root.next;
+	  for (; position > 0; position--)
+	    node = node->next;
+	}
+      else
+	{
+	  position = count - 1 - position;
+	  node = list->root.prev;
+	  for (; position > 0; position--)
+	    node = node->prev;
+	}
+
+      do
+	{
+	  int cmp = compar (node->value, elt);
+
+	  if (cmp > 0)
+	    break;
+	  if (cmp == 0)
+	    return node;
+	  node = node->next;
+	}
+      while (--high > 0);
+    }
+  return NULL;
+}
+
+static size_t
+gl_linked_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar,
+			      const void *elt)
+{
+  gl_list_node_t node;
+  size_t index;
+
+  for (node = list->root.next, index = 0;
+       node != &list->root;
+       node = node->next, index++)
+    {
+      int cmp = compar (node->value, elt);
+
+      if (cmp > 0)
+	break;
+      if (cmp == 0)
+	return index;
+    }
+  return (size_t)(-1);
+}
+
+static size_t
+gl_linked_sortedlist_indexof_from_to (gl_list_t list,
+				      gl_listelement_compar_fn compar,
+				      size_t low, size_t high,
+				      const void *elt)
+{
+  size_t count = list->count;
+
+  if (!(low <= high && high <= list->count))
+    /* Invalid arguments.  */
+    abort ();
+
+  high -= low;
+  if (high > 0)
+    {
+      /* Here we know low < count.  */
+      size_t index = low;
+      size_t position = low;
+      gl_list_node_t node;
+
+      if (position <= ((count - 1) / 2))
+	{
+	  node = list->root.next;
+	  for (; position > 0; position--)
+	    node = node->next;
+	}
+      else
+	{
+	  position = count - 1 - position;
+	  node = list->root.prev;
+	  for (; position > 0; position--)
+	    node = node->prev;
+	}
+
+      do
+	{
+	  int cmp = compar (node->value, elt);
+
+	  if (cmp > 0)
+	    break;
+	  if (cmp == 0)
+	    return index;
+	  node = node->next;
+	  index++;
+	}
+      while (--high > 0);
+    }
+  return (size_t)(-1);
+}
+
+static gl_list_node_t
+gl_linked_sortedlist_add (gl_list_t list, gl_listelement_compar_fn compar,
+			  const void *elt)
+{
+  gl_list_node_t node;
+
+  for (node = list->root.next; node != &list->root; node = node->next)
+    if (compar (node->value, elt) >= 0)
+      return gl_linked_add_before (list, node, elt);
+  return gl_linked_add_last (list, elt);
+}
+
+static bool
+gl_linked_sortedlist_remove (gl_list_t list, gl_listelement_compar_fn compar,
+			     const void *elt)
+{
+  gl_list_node_t node;
+
+  for (node = list->root.next; node != &list->root; node = node->next)
+    {
+      int cmp = compar (node->value, elt);
+
+      if (cmp > 0)
+	break;
+      if (cmp == 0)
+	return gl_linked_remove_node (list, node);
+    }
+  return false;
+}
diff --git a/src/bin/m4/lib/gl_anytree_oset.h b/src/bin/m4/lib/gl_anytree_oset.h
new file mode 100644
index 0000000000..b6b50b4bc9
--- /dev/null
+++ b/src/bin/m4/lib/gl_anytree_oset.h
@@ -0,0 +1,287 @@
+/* Ordered set data type implemented by a binary tree.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Common code of gl_avltree_oset.c and gl_rbtree_oset.c.  */
+
+/* An item on the stack used for iterating across the elements.  */
+typedef struct
+{
+  gl_oset_node_t node;
+  bool rightp;
+} iterstack_item_t;
+
+/* A stack used for iterating across the elements.  */
+typedef iterstack_item_t iterstack_t[MAXHEIGHT];
+
+static gl_oset_t
+gl_tree_create_empty (gl_oset_implementation_t implementation,
+		      gl_setelement_compar_fn compar_fn)
+{
+  struct gl_oset_impl *set = XMALLOC (struct gl_oset_impl);
+
+  set->base.vtable = implementation;
+  set->base.compar_fn = compar_fn;
+  set->root = NULL;
+  set->count = 0;
+
+  return set;
+}
+
+static size_t
+gl_tree_size (gl_oset_t set)
+{
+  return set->count;
+}
+
+static bool
+gl_tree_search (gl_oset_t set, const void *elt)
+{
+  gl_setelement_compar_fn compar = set->base.compar_fn;
+  gl_oset_node_t node;
+
+  for (node = set->root; node != NULL; )
+    {
+      int cmp = (compar != NULL
+		 ? compar (node->value, elt)
+		 : (node->value > elt ? 1 :
+		    node->value < elt ? -1 : 0));
+
+      if (cmp < 0)
+	node = node->right;
+      else if (cmp > 0)
+	node = node->left;
+      else /* cmp == 0 */
+	/* We have an element equal to ELT.  */
+	return true;
+    }
+  return false;
+}
+
+static bool
+gl_tree_search_atleast (gl_oset_t set,
+			gl_setelement_threshold_fn threshold_fn,
+			const void *threshold,
+			const void **eltp)
+{
+  gl_oset_node_t node;
+
+  for (node = set->root; node != NULL; )
+    {
+      if (! threshold_fn (node->value, threshold))
+	node = node->right;
+      else
+	{
+	  /* We have an element >= VALUE.  But we need the leftmost such
+	     element.  */
+	  gl_oset_node_t found = node;
+	  node = node->left;
+	  for (; node != NULL; )
+	    {
+	      if (! threshold_fn (node->value, threshold))
+		node = node->right;
+	      else
+		{
+		  found = node;
+		  node = node->left;
+		}
+	    }
+	  *eltp = found->value;
+	  return true;
+	}
+    }
+  return false;
+}
+
+static gl_oset_node_t
+gl_tree_search_node (gl_oset_t set, const void *elt)
+{
+  gl_setelement_compar_fn compar = set->base.compar_fn;
+  gl_oset_node_t node;
+
+  for (node = set->root; node != NULL; )
+    {
+      int cmp = (compar != NULL
+		 ? compar (node->value, elt)
+		 : (node->value > elt ? 1 :
+		    node->value < elt ? -1 : 0));
+
+      if (cmp < 0)
+	node = node->right;
+      else if (cmp > 0)
+	node = node->left;
+      else /* cmp == 0 */
+	/* We have an element equal to ELT.  */
+	return node;
+    }
+  return NULL;
+}
+
+static bool
+gl_tree_add (gl_oset_t set, const void *elt)
+{
+  gl_setelement_compar_fn compar;
+  gl_oset_node_t node = set->root;
+
+  if (node == NULL)
+    {
+      gl_tree_add_first (set, elt);
+      return true;
+    }
+
+  compar = set->base.compar_fn;
+
+  for (;;)
+    {
+      int cmp = (compar != NULL
+		 ? compar (node->value, elt)
+		 : (node->value > elt ? 1 :
+		    node->value < elt ? -1 : 0));
+
+      if (cmp < 0)
+	{
+	  if (node->right == NULL)
+	    {
+	      gl_tree_add_after (set, node, elt);
+	      return true;
+	    }
+	  node = node->right;
+	}
+      else if (cmp > 0)
+	{
+	  if (node->left == NULL)
+	    {
+	      gl_tree_add_before (set, node, elt);
+	      return true;
+	    }
+	  node = node->left;
+	}
+      else /* cmp == 0 */
+	return false;
+    }
+}
+
+static bool
+gl_tree_remove (gl_oset_t set, const void *elt)
+{
+  gl_oset_node_t node = gl_tree_search_node (set, elt);
+
+  if (node != NULL)
+    return gl_tree_remove_node (set, node);
+  else
+    return false;
+}
+
+static void
+gl_tree_oset_free (gl_oset_t set)
+{
+  /* Iterate across all elements in post-order.  */
+  gl_oset_node_t node = set->root;
+  iterstack_t stack;
+  iterstack_item_t *stack_ptr = &stack[0];
+
+  for (;;)
+    {
+      /* Descend on left branch.  */
+      for (;;)
+	{
+	  if (node == NULL)
+	    break;
+	  stack_ptr->node = node;
+	  stack_ptr->rightp = false;
+	  node = node->left;
+	  stack_ptr++;
+	}
+      /* Climb up again.  */
+      for (;;)
+	{
+	  if (stack_ptr == &stack[0])
+	    goto done_iterate;
+	  stack_ptr--;
+	  node = stack_ptr->node;
+	  if (!stack_ptr->rightp)
+	    break;
+	  /* Free the current node.  */
+	  free (node);
+	}
+      /* Descend on right branch.  */
+      stack_ptr->rightp = true;
+      node = node->right;
+      stack_ptr++;
+    }
+ done_iterate:
+  free (set);
+}
+
+/* --------------------- gl_oset_iterator_t Data Type --------------------- */
+
+static gl_oset_iterator_t
+gl_tree_iterator (gl_oset_t set)
+{
+  gl_oset_iterator_t result;
+  gl_oset_node_t node;
+
+  result.vtable = set->base.vtable;
+  result.set = set;
+  /* Start node is the leftmost node.  */
+  node = set->root;
+  if (node != NULL)
+    while (node->left != NULL)
+      node = node->left;
+  result.p = node;
+  /* End point is past the rightmost node.  */
+  result.q = NULL;
+#ifdef lint
+  result.i = 0;
+  result.j = 0;
+  result.count = 0;
+#endif
+
+  return result;
+}
+
+static bool
+gl_tree_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
+{
+  if (iterator->p != iterator->q)
+    {
+      gl_oset_node_t node = (gl_oset_node_t) iterator->p;
+      *eltp = node->value;
+      /* Advance to the next node.  */
+      if (node->right != NULL)
+	{
+	  node = node->right;
+	  while (node->left != NULL)
+	    node = node->left;
+	}
+      else
+	{
+	  while (node->parent != NULL && node->parent->right == node)
+	    node = node->parent;
+	  node = node->parent;
+	}
+      iterator->p = node;
+      return true;
+    }
+  else
+    return false;
+}
+
+static void
+gl_tree_iterator_free (gl_oset_iterator_t *iterator)
+{
+}
diff --git a/src/bin/m4/lib/gl_avltree_oset.c b/src/bin/m4/lib/gl_avltree_oset.c
new file mode 100644
index 0000000000..1e38b984f3
--- /dev/null
+++ b/src/bin/m4/lib/gl_avltree_oset.c
@@ -0,0 +1,572 @@
+/* Ordered set data type implemented by a binary tree.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "gl_avltree_oset.h"
+
+#include <stdlib.h>
+
+#include "xalloc.h"
+
+/* An AVL tree is a binary tree where
+   1. The height of each node is calculated as
+	heightof(node) = 1 + max (heightof(node.left), heightof(node.right)).
+   2. The heights of the subtrees of each node differ by at most 1:
+	| heightof(right) - heightof(left) | <= 1.
+   3. The index of the elements in the node.left subtree are smaller than
+      the index of node.
+      The index of the elements in the node.right subtree are larger than
+      the index of node.
+ */
+
+/* -------------------------- gl_oset_t Data Type -------------------------- */
+
+/* Tree node implementation, valid for this file only.  */
+struct gl_oset_node_impl
+{
+  struct gl_oset_node_impl *left;   /* left branch, or NULL */
+  struct gl_oset_node_impl *right;  /* right branch, or NULL */
+  /* Parent pointer, or NULL. The parent pointer is not needed for most
+     operations.  It is needed so that a gl_oset_node_t can be returned
+     without memory allocation, on which the functions gl_oset_remove_node,
+     gl_oset_add_before, gl_oset_add_after can be implemented.  */
+  struct gl_oset_node_impl *parent;
+  int balance;                      /* heightof(right) - heightof(left),
+				       always = -1 or 0 or 1 */
+  const void *value;
+};
+typedef struct gl_oset_node_impl * gl_oset_node_t;
+
+/* Concrete gl_oset_impl type, valid for this file only.  */
+struct gl_oset_impl
+{
+  struct gl_oset_impl_base base;
+  struct gl_oset_node_impl *root;   /* root node or NULL */
+  size_t count;                     /* number of nodes */
+};
+
+/* An AVL tree of height h has at least F_(h+2) [Fibonacci number] and at most
+   2^h - 1 elements.  So, h <= 84 (because a tree of height h >= 85 would have
+   at least F_87 elements, and because even on 64-bit machines,
+     sizeof (gl_oset_node_impl) * F_87 > 2^64
+   this would exceed the address space of the machine.  */
+#define MAXHEIGHT 83
+
+/* Ensure the tree is balanced, after an insertion or deletion operation.
+   The height of NODE is incremented by HEIGHT_DIFF (1 or -1).
+   PARENT = NODE->parent.  (NODE can also be NULL.  But PARENT is non-NULL.)
+   Rotation operations are performed starting at PARENT (not NODE itself!).  */
+static void
+rebalance (gl_oset_t set,
+	   gl_oset_node_t node, int height_diff, gl_oset_node_t parent)
+{
+  for (;;)
+    {
+      gl_oset_node_t child;
+      int previous_balance;
+      int balance_diff;
+      gl_oset_node_t nodeleft;
+      gl_oset_node_t noderight;
+
+      child = node;
+      node = parent;
+
+      previous_balance = node->balance;
+
+      /* The balance of NODE is incremented by BALANCE_DIFF: +1 if the right
+	 branch's height has increased by 1 or the left branch's height has
+	 decreased by 1, -1 if the right branch's height has decreased by 1 or
+	 the left branch's height has increased by 1, 0 if no height change.  */
+      if (node->left != NULL || node->right != NULL)
+	balance_diff = (child == node->right ? height_diff : -height_diff);
+      else
+	/* Special case where above formula doesn't work, because the caller
+	   didn't tell whether node's left or right branch shrunk from height 1
+	   to NULL.  */
+	balance_diff = - previous_balance;
+
+      node->balance += balance_diff;
+      if (balance_diff == previous_balance)
+	{
+	  /* node->balance is outside the range [-1,1].  Must rotate.  */
+	  gl_oset_node_t *nodep;
+
+	  if (node->parent == NULL)
+	    /* node == set->root */
+	    nodep = &set->root;
+	  else if (node->parent->left == node)
+	    nodep = &node->parent->left;
+	  else if (node->parent->right == node)
+	    nodep = &node->parent->right;
+	  else
+	    abort ();
+
+	  nodeleft = node->left;
+	  noderight = node->right;
+
+	  if (balance_diff < 0)
+	    {
+	      /* node->balance = -2.  The subtree is heavier on the left side.
+		 Rotate from left to right:
+
+				  *
+				/   \
+			     h+2      h
+	       */
+	      gl_oset_node_t nodeleftright = nodeleft->right;
+	      if (nodeleft->balance <= 0)
+		{
+		  /*
+			      *                    h+2|h+3
+			    /   \                  /    \
+			 h+2      h      -->      /   h+1|h+2
+			 / \                      |    /    \
+		       h+1 h|h+1                 h+1  h|h+1  h
+		   */
+		  node->left = nodeleftright;
+		  nodeleft->right = node;
+
+		  nodeleft->parent = node->parent;
+		  node->parent = nodeleft;
+		  if (nodeleftright != NULL)
+		    nodeleftright->parent = node;
+
+		  nodeleft->balance += 1;
+		  node->balance = - nodeleft->balance;
+
+		  *nodep = nodeleft;
+		  height_diff = (height_diff < 0
+				 ? /* noderight's height had been decremented from
+				      h+1 to h.  The subtree's height changes from
+				      h+3 to h+2|h+3.  */
+				   nodeleft->balance - 1
+				 : /* nodeleft's height had been incremented from
+				      h+1 to h+2.  The subtree's height changes from
+				      h+2 to h+2|h+3.  */
+				   nodeleft->balance);
+		}
+	      else
+		{
+		  /*
+			    *                     h+2
+			  /   \                 /     \
+		       h+2      h      -->    h+1     h+1
+		       / \                    / \     / \
+		      h  h+1                 h   L   R   h
+			 / \
+			L   R
+
+		   */
+		  gl_oset_node_t L = nodeleft->right = nodeleftright->left;
+		  gl_oset_node_t R = node->left = nodeleftright->right;
+		  nodeleftright->left = nodeleft;
+		  nodeleftright->right = node;
+
+		  nodeleftright->parent = node->parent;
+		  if (L != NULL)
+		    L->parent = nodeleft;
+		  if (R != NULL)
+		    R->parent = node;
+		  nodeleft->parent = nodeleftright;
+		  node->parent = nodeleftright;
+
+		  nodeleft->balance = (nodeleftright->balance > 0 ? -1 : 0);
+		  node->balance = (nodeleftright->balance < 0 ? 1 : 0);
+		  nodeleftright->balance = 0;
+
+		  *nodep = nodeleftright;
+		  height_diff = (height_diff < 0
+				 ? /* noderight's height had been decremented from
+				      h+1 to h.  The subtree's height changes from
+				      h+3 to h+2.  */
+				   -1
+				 : /* nodeleft's height had been incremented from
+				      h+1 to h+2.  The subtree's height changes from
+				      h+2 to h+2.  */
+				   0);
+		}
+	    }
+	  else
+	    {
+	      /* node->balance = 2.  The subtree is heavier on the right side.
+		 Rotate from right to left:
+
+				  *
+				/   \
+			      h      h+2
+	       */
+	      gl_oset_node_t noderightleft = noderight->left;
+	      if (noderight->balance >= 0)
+		{
+		  /*
+			      *                    h+2|h+3
+			    /   \                   /    \
+			  h      h+2     -->    h+1|h+2   \
+				 / \            /    \    |
+			     h|h+1 h+1         h   h|h+1 h+1
+		   */
+		  node->right = noderightleft;
+		  noderight->left = node;
+
+		  noderight->parent = node->parent;
+		  node->parent = noderight;
+		  if (noderightleft != NULL)
+		    noderightleft->parent = node;
+
+		  noderight->balance -= 1;
+		  node->balance = - noderight->balance;
+
+		  *nodep = noderight;
+		  height_diff = (height_diff < 0
+				 ? /* nodeleft's height had been decremented from
+				      h+1 to h.  The subtree's height changes from
+				      h+3 to h+2|h+3.  */
+				   - noderight->balance - 1
+				 : /* noderight's height had been incremented from
+				      h+1 to h+2.  The subtree's height changes from
+				      h+2 to h+2|h+3.  */
+				   - noderight->balance);
+		}
+	      else
+		{
+		  /*
+			    *                    h+2
+			  /   \                /     \
+			h      h+2    -->    h+1     h+1
+			       / \           / \     / \
+			     h+1  h         h   L   R   h
+			     / \
+			    L   R
+
+		   */
+		  gl_oset_node_t L = node->right = noderightleft->left;
+		  gl_oset_node_t R = noderight->left = noderightleft->right;
+		  noderightleft->left = node;
+		  noderightleft->right = noderight;
+
+		  noderightleft->parent = node->parent;
+		  if (L != NULL)
+		    L->parent = node;
+		  if (R != NULL)
+		    R->parent = noderight;
+		  node->parent = noderightleft;
+		  noderight->parent = noderightleft;
+
+		  node->balance = (noderightleft->balance > 0 ? -1 : 0);
+		  noderight->balance = (noderightleft->balance < 0 ? 1 : 0);
+		  noderightleft->balance = 0;
+
+		  *nodep = noderightleft;
+		  height_diff = (height_diff < 0
+				 ? /* nodeleft's height had been decremented from
+				      h+1 to h.  The subtree's height changes from
+				      h+3 to h+2.  */
+				   -1
+				 : /* noderight's height had been incremented from
+				      h+1 to h+2.  The subtree's height changes from
+				      h+2 to h+2.  */
+				   0);
+		}
+	    }
+	  node = *nodep;
+	}
+      else
+	{
+	  /* No rotation needed.  Only propagation of the height change to the
+	     next higher level.  */
+	  if (height_diff < 0)
+	    height_diff = (previous_balance == 0 ? 0 : -1);
+	  else
+	    height_diff = (node->balance == 0 ? 0 : 1);
+	}
+
+      if (height_diff == 0)
+	break;
+
+      parent = node->parent;
+      if (parent == NULL)
+	break;
+    }
+}
+
+static gl_oset_node_t
+gl_tree_add_first (gl_oset_t set, const void *elt)
+{
+  /* Create new node.  */
+  gl_oset_node_t new_node = XMALLOC (struct gl_oset_node_impl);
+
+  new_node->left = NULL;
+  new_node->right = NULL;
+  new_node->balance = 0;
+  new_node->value = elt;
+
+  /* Add it to the tree.  */
+  if (set->root == NULL)
+    {
+      set->root = new_node;
+      new_node->parent = NULL;
+    }
+  else
+    {
+      gl_oset_node_t node;
+
+      for (node = set->root; node->left != NULL; )
+	node = node->left;
+
+      node->left = new_node;
+      new_node->parent = node;
+      node->balance--;
+
+      /* Rebalance.  */
+      if (node->right == NULL && node->parent != NULL)
+	rebalance (set, node, 1, node->parent);
+    }
+
+  set->count++;
+  return new_node;
+}
+
+static gl_oset_node_t
+gl_tree_add_before (gl_oset_t set, gl_oset_node_t node, const void *elt)
+{
+  /* Create new node.  */
+  gl_oset_node_t new_node = XMALLOC (struct gl_oset_node_impl);
+  bool height_inc;
+
+  new_node->left = NULL;
+  new_node->right = NULL;
+  new_node->balance = 0;
+  new_node->value = elt;
+
+  /* Add it to the tree.  */
+  if (node->left == NULL)
+    {
+      node->left = new_node;
+      node->balance--;
+      height_inc = (node->right == NULL);
+    }
+  else
+    {
+      for (node = node->left; node->right != NULL; )
+	node = node->right;
+      node->right = new_node;
+      node->balance++;
+      height_inc = (node->left == NULL);
+    }
+  new_node->parent = node;
+
+  /* Rebalance.  */
+  if (height_inc && node->parent != NULL)
+    rebalance (set, node, 1, node->parent);
+
+  set->count++;
+  return new_node;
+}
+
+static gl_oset_node_t
+gl_tree_add_after (gl_oset_t set, gl_oset_node_t node, const void *elt)
+{
+  /* Create new node.  */
+  gl_oset_node_t new_node = XMALLOC (struct gl_oset_node_impl);
+  bool height_inc;
+
+  new_node->left = NULL;
+  new_node->right = NULL;
+  new_node->balance = 0;
+  new_node->value = elt;
+
+  /* Add it to the tree.  */
+  if (node->right == NULL)
+    {
+      node->right = new_node;
+      node->balance++;
+      height_inc = (node->left == NULL);
+    }
+  else
+    {
+      for (node = node->right; node->left != NULL; )
+	node = node->left;
+      node->left = new_node;
+      node->balance--;
+      height_inc = (node->right == NULL);
+    }
+  new_node->parent = node;
+
+  /* Rebalance.  */
+  if (height_inc && node->parent != NULL)
+    rebalance (set, node, 1, node->parent);
+
+  set->count++;
+  return new_node;
+}
+
+static bool
+gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
+{
+  gl_oset_node_t parent = node->parent;
+
+  if (node->left == NULL)
+    {
+      /* Replace node with node->right.  */
+      gl_oset_node_t child = node->right;
+
+      if (child != NULL)
+	child->parent = parent;
+      if (parent == NULL)
+	set->root = child;
+      else
+	{
+	  if (parent->left == node)
+	    parent->left = child;
+	  else /* parent->right == node */
+	    parent->right = child;
+
+	  rebalance (set, child, -1, parent);
+	}
+    }
+  else if (node->right == NULL)
+    {
+      /* It is not absolutely necessary to treat this case.  But the more
+	 general case below is more complicated, hence slower.  */
+      /* Replace node with node->left.  */
+      gl_oset_node_t child = node->left;
+
+      child->parent = parent;
+      if (parent == NULL)
+	set->root = child;
+      else
+	{
+	  if (parent->left == node)
+	    parent->left = child;
+	  else /* parent->right == node */
+	    parent->right = child;
+
+	  rebalance (set, child, -1, parent);
+	}
+    }
+  else
+    {
+      /* Replace node with the rightmost element of the node->left subtree.  */
+      gl_oset_node_t subst;
+      gl_oset_node_t subst_parent;
+      gl_oset_node_t child;
+
+      for (subst = node->left; subst->right != NULL; )
+	subst = subst->right;
+
+      subst_parent = subst->parent;
+
+      child = subst->left;
+
+      /* The case subst_parent == node is special:  If we do nothing special,
+	 we get confusion about node->left, subst->left and child->parent.
+	   subst_parent == node
+	   <==> The 'for' loop above terminated immediately.
+	   <==> subst == subst_parent->left
+		[otherwise subst == subst_parent->right]
+	 In this case, we would need to first set
+	   child->parent = node; node->left = child;
+	 and later - when we copy subst into node's position - again
+	   child->parent = subst; subst->left = child;
+	 Altogether a no-op.  */
+      if (subst_parent != node)
+	{
+	  if (child != NULL)
+	    child->parent = subst_parent;
+	  subst_parent->right = child;
+	}
+
+      /* Copy subst into node's position.
+	 (This is safer than to copy subst's value into node, keep node in
+	 place, and free subst.)  */
+      if (subst_parent != node)
+	{
+	  subst->left = node->left;
+	  subst->left->parent = subst;
+	}
+      subst->right = node->right;
+      subst->right->parent = subst;
+      subst->balance = node->balance;
+      subst->parent = parent;
+      if (parent == NULL)
+	set->root = subst;
+      else if (parent->left == node)
+	parent->left = subst;
+      else /* parent->right == node */
+	parent->right = subst;
+
+      /* Rebalancing starts at child's parent, that is subst_parent -
+	 except when subst_parent == node.  In this case, we need to use
+	 its replacement, subst.  */
+      rebalance (set, child, -1, subst_parent != node ? subst_parent : subst);
+    }
+
+  set->count--;
+  free (node);
+  return true;
+}
+
+/* Generic binary tree code.  */
+#include "gl_anytree_oset.h"
+
+/* For debugging.  */
+static unsigned int
+check_invariants (gl_oset_node_t node, gl_oset_node_t parent, size_t *counterp)
+{
+  unsigned int left_height =
+    (node->left != NULL ? check_invariants (node->left, node, counterp) : 0);
+  unsigned int right_height =
+    (node->right != NULL ? check_invariants (node->right, node, counterp) : 0);
+  int balance = (int)right_height - (int)left_height;
+
+  if (!(node->parent == parent))
+    abort ();
+  if (!(balance >= -1 && balance <= 1))
+    abort ();
+  if (!(node->balance == balance))
+    abort ();
+
+  (*counterp)++;
+
+  return 1 + (left_height > right_height ? left_height : right_height);
+}
+void
+gl_avltree_oset_check_invariants (gl_oset_t set)
+{
+  size_t counter = 0;
+  if (set->root != NULL)
+    check_invariants (set->root, NULL, &counter);
+  if (!(set->count == counter))
+    abort ();
+}
+
+const struct gl_oset_implementation gl_avltree_oset_implementation =
+  {
+    gl_tree_create_empty,
+    gl_tree_size,
+    gl_tree_search,
+    gl_tree_search_atleast,
+    gl_tree_add,
+    gl_tree_remove,
+    gl_tree_oset_free,
+    gl_tree_iterator,
+    gl_tree_iterator_next,
+    gl_tree_iterator_free
+  };
diff --git a/src/bin/m4/lib/gl_avltree_oset.h b/src/bin/m4/lib/gl_avltree_oset.h
new file mode 100644
index 0000000000..27f75d22d0
--- /dev/null
+++ b/src/bin/m4/lib/gl_avltree_oset.h
@@ -0,0 +1,35 @@
+/* Ordered set data type implemented by a binary tree.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GL_AVLTREE_OSET_H
+#define _GL_AVLTREE_OSET_H
+
+#include "gl_oset.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const struct gl_oset_implementation gl_avltree_oset_implementation;
+#define GL_AVLTREE_OSET &gl_avltree_oset_implementation
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _GL_AVLTREE_OSET_H */
diff --git a/src/bin/m4/lib/gl_linkedhash_list.c b/src/bin/m4/lib/gl_linkedhash_list.c
new file mode 100644
index 0000000000..89173f51bc
--- /dev/null
+++ b/src/bin/m4/lib/gl_linkedhash_list.c
@@ -0,0 +1,123 @@
+/* Sequential list data type implemented by a hash table with a linked list.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "gl_linkedhash_list.h"
+
+#include <stdint.h> /* for SIZE_MAX */
+#include <stdlib.h>
+
+#include "xalloc.h"
+#include "xsize.h"
+
+#ifndef uintptr_t
+# define uintptr_t unsigned long
+#endif
+
+#define WITH_HASHTABLE 1
+
+/* -------------------------- gl_list_t Data Type -------------------------- */
+
+/* Generic hash-table code.  */
+#include "gl_anyhash_list1.h"
+
+/* Generic linked list code.  */
+#include "gl_anylinked_list1.h"
+
+/* Generic hash-table code.  */
+#include "gl_anyhash_list2.h"
+
+/* Resize the hash table if needed, after list->count was incremented.  */
+static inline void
+hash_resize_after_add (gl_list_t list)
+{
+  size_t count = list->count;
+  size_t estimate = xsum (count, count / 2); /* 1.5 * count */
+  if (estimate > list->table_size)
+    hash_resize (list, estimate);
+}
+
+/* Add a node to the hash table structure.  */
+static inline void
+add_to_bucket (gl_list_t list, gl_list_node_t node)
+{
+  size_t bucket = node->h.hashcode % list->table_size;
+
+  node->h.hash_next = list->table[bucket];
+  list->table[bucket] = &node->h;
+}
+
+/* Remove a node from the hash table structure.  */
+static inline void
+remove_from_bucket (gl_list_t list, gl_list_node_t node)
+{
+  size_t bucket = node->h.hashcode % list->table_size;
+  gl_hash_entry_t *p;
+
+  for (p = &list->table[bucket]; ; p = &(*p)->hash_next)
+    {
+      if (*p == &node->h)
+	{
+	  *p = node->h.hash_next;
+	  break;
+	}
+      if (*p == NULL)
+	/* node is not in the right bucket.  Did the hash codes
+	   change inadvertently?  */
+	abort ();
+    }
+}
+
+/* Generic linked list code.  */
+#include "gl_anylinked_list2.h"
+
+
+const struct gl_list_implementation gl_linkedhash_list_implementation =
+  {
+    gl_linked_create_empty,
+    gl_linked_create,
+    gl_linked_size,
+    gl_linked_node_value,
+    gl_linked_next_node,
+    gl_linked_previous_node,
+    gl_linked_get_at,
+    gl_linked_set_at,
+    gl_linked_search_from_to,
+    gl_linked_indexof_from_to,
+    gl_linked_add_first,
+    gl_linked_add_last,
+    gl_linked_add_before,
+    gl_linked_add_after,
+    gl_linked_add_at,
+    gl_linked_remove_node,
+    gl_linked_remove_at,
+    gl_linked_remove,
+    gl_linked_list_free,
+    gl_linked_iterator,
+    gl_linked_iterator_from_to,
+    gl_linked_iterator_next,
+    gl_linked_iterator_free,
+    gl_linked_sortedlist_search,
+    gl_linked_sortedlist_search_from_to,
+    gl_linked_sortedlist_indexof,
+    gl_linked_sortedlist_indexof_from_to,
+    gl_linked_sortedlist_add,
+    gl_linked_sortedlist_remove
+  };
diff --git a/src/bin/m4/lib/gl_linkedhash_list.h b/src/bin/m4/lib/gl_linkedhash_list.h
new file mode 100644
index 0000000000..d3e71ed95d
--- /dev/null
+++ b/src/bin/m4/lib/gl_linkedhash_list.h
@@ -0,0 +1,35 @@
+/* Sequential list data type implemented by a hash table with a linked list.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GL_LINKEDHASH_LIST_H
+#define _GL_LINKEDHASH_LIST_H
+
+#include "gl_list.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const struct gl_list_implementation gl_linkedhash_list_implementation;
+#define GL_LINKEDHASH_LIST &gl_linkedhash_list_implementation
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _GL_LINKEDHASH_LIST_H */
diff --git a/src/bin/m4/lib/gl_list.c b/src/bin/m4/lib/gl_list.c
new file mode 100644
index 0000000000..cbc765a944
--- /dev/null
+++ b/src/bin/m4/lib/gl_list.c
@@ -0,0 +1,272 @@
+/* Abstract sequential list data type.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "gl_list.h"
+
+#if !HAVE_INLINE
+
+/* Define all functions of this file as inline accesses to the
+   struct gl_list_implementation.
+   Use #define to avoid a warning because of extern vs. static.  */
+
+gl_list_t
+gl_list_create_empty (gl_list_implementation_t implementation,
+		      gl_listelement_equals_fn equals_fn,
+		      gl_listelement_hashcode_fn hashcode_fn,
+		      bool allow_duplicates)
+{
+  return implementation->create_empty (implementation, equals_fn, hashcode_fn,
+				       allow_duplicates);
+}
+
+gl_list_t
+gl_list_create (gl_list_implementation_t implementation,
+		gl_listelement_equals_fn equals_fn,
+		gl_listelement_hashcode_fn hashcode_fn,
+		bool allow_duplicates,
+		size_t count, const void **contents)
+{
+  return implementation->create (implementation, equals_fn, hashcode_fn,
+				 allow_duplicates, count, contents);
+}
+
+size_t
+gl_list_size (gl_list_t list)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->size (list);
+}
+
+const void *
+gl_list_node_value (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->node_value (list, node);
+}
+
+gl_list_node_t
+gl_list_next_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->next_node (list, node);
+}
+
+gl_list_node_t
+gl_list_previous_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->previous_node (list, node);
+}
+
+const void *
+gl_list_get_at (gl_list_t list, size_t position)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->get_at (list, position);
+}
+
+gl_list_node_t
+gl_list_set_at (gl_list_t list, size_t position, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->set_at (list, position, elt);
+}
+
+gl_list_node_t
+gl_list_search (gl_list_t list, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->search_from_to (list, 0, size, elt);
+}
+
+gl_list_node_t
+gl_list_search_from (gl_list_t list, size_t start_index, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->search_from_to (list, start_index, size, elt);
+}
+
+gl_list_node_t
+gl_list_search_from_to (gl_list_t list, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->search_from_to (list, start_index, end_index, elt);
+}
+
+size_t
+gl_list_indexof (gl_list_t list, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->indexof_from_to (list, 0, size, elt);
+}
+
+size_t
+gl_list_indexof_from (gl_list_t list, size_t start_index, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->indexof_from_to (list, start_index, size, elt);
+}
+
+size_t
+gl_list_indexof_from_to (gl_list_t list, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->indexof_from_to (list, start_index, end_index, elt);
+}
+
+gl_list_node_t
+gl_list_add_first (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_first (list, elt);
+}
+
+gl_list_node_t
+gl_list_add_last (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_last (list, elt);
+}
+
+gl_list_node_t
+gl_list_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_before (list, node, elt);
+}
+
+gl_list_node_t
+gl_list_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_after (list, node, elt);
+}
+
+gl_list_node_t
+gl_list_add_at (gl_list_t list, size_t position, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_at (list, position, elt);
+}
+
+bool
+gl_list_remove_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->remove_node (list, node);
+}
+
+bool
+gl_list_remove_at (gl_list_t list, size_t position)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->remove_at (list, position);
+}
+
+bool
+gl_list_remove (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->remove (list, elt);
+}
+
+void
+gl_list_free (gl_list_t list)
+{
+  ((const struct gl_list_impl_base *) list)->vtable->list_free (list);
+}
+
+gl_list_iterator_t
+gl_list_iterator (gl_list_t list)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->iterator (list);
+}
+
+gl_list_iterator_t
+gl_list_iterator_from_to (gl_list_t list, size_t start_index, size_t end_index)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->iterator_from_to (list, start_index, end_index);
+}
+
+bool
+gl_list_iterator_next (gl_list_iterator_t *iterator,
+		       const void **eltp, gl_list_node_t *nodep)
+{
+  return iterator->vtable->iterator_next (iterator, eltp, nodep);
+}
+
+void
+gl_list_iterator_free (gl_list_iterator_t *iterator)
+{
+  iterator->vtable->iterator_free (iterator);
+}
+
+gl_list_node_t
+gl_sortedlist_search (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_search (list, compar, elt);
+}
+
+gl_list_node_t
+gl_sortedlist_search_from_to (gl_list_t list, gl_listelement_compar_fn compar, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_search_from_to (list, compar, start_index, end_index,
+				      elt);
+}
+
+size_t
+gl_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_indexof (list, compar, elt);
+}
+
+size_t
+gl_sortedlist_indexof_from_to (gl_list_t list, gl_listelement_compar_fn compar, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_indexof_from_to (list, compar, start_index, end_index,
+				       elt);
+}
+
+gl_list_node_t
+gl_sortedlist_add (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_add (list, compar, elt);
+}
+
+bool
+gl_sortedlist_remove (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_remove (list, compar, elt);
+}
+
+#endif
diff --git a/src/bin/m4/lib/gl_list.h b/src/bin/m4/lib/gl_list.h
new file mode 100644
index 0000000000..b97a6a42a3
--- /dev/null
+++ b/src/bin/m4/lib/gl_list.h
@@ -0,0 +1,724 @@
+/* Abstract sequential list data type.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GL_LIST_H
+#define _GL_LIST_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* gl_list is an abstract list data type.  It can contain any number of
+   objects ('void *' or 'const void *' pointers) in any given order.
+   Duplicates are allowed, but can optionally be forbidden.
+
+   There are several implementations of this list datatype, optimized for
+   different operations or for memory.  You can start using the simplest list
+   implementation, GL_ARRAY_LIST, and switch to a different implementation
+   later, when you realize which operations are performed the most frequently.
+   The API of the different implementations is exactly the same; when
+   switching to a different implementation, you only have to change the
+   gl_list_create call.
+
+   The implementations are:
+     GL_ARRAY_LIST        a growable array
+     GL_CARRAY_LIST       a growable circular array
+     GL_LINKED_LIST       a linked list
+     GL_AVLTREE_LIST      a binary tree (AVL tree)
+     GL_RBTREE_LIST       a binary tree (red-black tree)
+     GL_LINKEDHASH_LIST   a hash table with a linked list
+     GL_AVLTREEHASH_LIST  a hash table with a binary tree (AVL tree)
+     GL_RBTREEHASH_LIST   a hash table with a binary tree (red-black tree)
+
+   The memory consumption is asymptotically the same: O(1) for every object
+   in the list.  When looking more closely at the average memory consumed
+   for an object, GL_ARRAY_LIST is the most compact representation, and
+   GL_LINKEDHASH_LIST and GL_TREEHASH_LIST need more memory.
+
+   The guaranteed average performance of the operations is, for a list of
+   n elements:
+
+   Operation                  ARRAY    LINKED    TREE    LINKEDHASH   TREEHASH
+			      CARRAY                   with|without with|without
+							 duplicates  duplicates
+
+   gl_list_size                O(1)     O(1)     O(1)      O(1)         O(1)
+   gl_list_node_value          O(1)     O(1)     O(1)      O(1)         O(1)
+   gl_list_next_node           O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_list_previous_node       O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_list_get_at              O(1)     O(n)   O(log n)    O(n)       O(log n)
+   gl_list_set_at              O(1)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_list_search              O(n)     O(n)     O(n)    O(n)/O(1)    O(log n)/O(1)
+   gl_list_search_from         O(n)     O(n)     O(n)    O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_search_from_to      O(n)     O(n)     O(n)    O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_indexof             O(n)     O(n)     O(n)      O(n)       O(log n)
+   gl_list_indexof_from        O(n)     O(n)     O(n)      O(n)    O((log n)²)/O(log n)
+   gl_list_indexof_from_to     O(n)     O(n)     O(n)      O(n)    O((log n)²)/O(log n)
+   gl_list_add_first         O(n)/O(1)  O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_last            O(1)     O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_before          O(n)     O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_after           O(n)     O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_at              O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_list_remove_node         O(n)     O(1)   O(log n)  O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_remove_at           O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_list_remove              O(n)     O(n)     O(n)    O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_iterator            O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_list_iterator_from_to    O(1)     O(n)   O(log n)    O(n)       O(log n)
+   gl_list_iterator_next       O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_sortedlist_search      O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_search_from O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_indexof     O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_indexof_fro O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_add           O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_sortedlist_remove        O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+ */
+
+/* -------------------------- gl_list_t Data Type -------------------------- */
+
+/* Type of function used to compare two elements.
+   NULL denotes pointer comparison.  */
+typedef bool (*gl_listelement_equals_fn) (const void *elt1, const void *elt2);
+
+/* Type of function used to compute a hash code.
+   NULL denotes a function that depends only on the pointer itself.  */
+typedef size_t (*gl_listelement_hashcode_fn) (const void *elt);
+
+struct gl_list_impl;
+/* Type representing an entire list.  */
+typedef struct gl_list_impl * gl_list_t;
+
+struct gl_list_node_impl;
+/* Type representing the position of an element in the list, in a way that
+   is more adapted to the list implementation than a plain index.
+   Note: It is invalidated by insertions and removals!  */
+typedef struct gl_list_node_impl * gl_list_node_t;
+
+struct gl_list_implementation;
+/* Type representing a list datatype implementation.  */
+typedef const struct gl_list_implementation * gl_list_implementation_t;
+
+/* Create an empty list.
+   IMPLEMENTATION is one of GL_ARRAY_LIST, GL_CARRAY_LIST, GL_LINKED_LIST,
+   GL_AVLTREE_LIST, GL_RBTREE_LIST, GL_LINKEDHASH_LIST, GL_AVLTREEHASH_LIST,
+   GL_RBTREEHASH_LIST.
+   EQUALS_FN is an element comparison function or NULL.
+   HASHCODE_FN is an element hash code function or NULL.
+   ALLOW_DUPLICATES is false if duplicate elements shall not be allowed in
+   the list. The implementation may verify this at runtime.  */
+extern gl_list_t gl_list_create_empty (gl_list_implementation_t implementation,
+				       gl_listelement_equals_fn equals_fn,
+				       gl_listelement_hashcode_fn hashcode_fn,
+				       bool allow_duplicates);
+
+/* Create a list with given contents.
+   IMPLEMENTATION is one of GL_ARRAY_LIST, GL_CARRAY_LIST, GL_LINKED_LIST,
+   GL_AVLTREE_LIST, GL_RBTREE_LIST, GL_LINKEDHASH_LIST, GL_AVLTREEHASH_LIST,
+   GL_RBTREEHASH_LIST.
+   EQUALS_FN is an element comparison function or NULL.
+   HASHCODE_FN is an element hash code function or NULL.
+   ALLOW_DUPLICATES is false if duplicate elements shall not be allowed in
+   the list. The implementation may verify this at runtime.
+   COUNT is the number of initial elements.
+   CONTENTS[0..COUNT-1] is the initial contents.  */
+extern gl_list_t gl_list_create (gl_list_implementation_t implementation,
+				 gl_listelement_equals_fn equals_fn,
+				 gl_listelement_hashcode_fn hashcode_fn,
+				 bool allow_duplicates,
+				 size_t count, const void **contents);
+
+/* Return the current number of elements in a list.  */
+extern size_t gl_list_size (gl_list_t list);
+
+/* Return the element value represented by a list node.  */
+extern const void * gl_list_node_value (gl_list_t list, gl_list_node_t node);
+
+/* Return the node immediately after the given node in the list, or NULL
+   if the given node is the last (rightmost) one in the list.  */
+extern gl_list_node_t gl_list_next_node (gl_list_t list, gl_list_node_t node);
+
+/* Return the node immediately before the given node in the list, or NULL
+   if the given node is the first (leftmost) one in the list.  */
+extern gl_list_node_t gl_list_previous_node (gl_list_t list, gl_list_node_t node);
+
+/* Return the element at a given position in the list.
+   POSITION must be >= 0 and < gl_list_size (list).  */
+extern const void * gl_list_get_at (gl_list_t list, size_t position);
+
+/* Replace the element at a given position in the list.
+   POSITION must be >= 0 and < gl_list_size (list).
+   Return its node.  */
+extern gl_list_node_t gl_list_set_at (gl_list_t list, size_t position,
+				      const void *elt);
+
+/* Search whether an element is already in the list.
+   Return its node if found, or NULL if not present in the list.  */
+extern gl_list_node_t gl_list_search (gl_list_t list, const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX.
+   Return its node if found, or NULL if not present in the list.  */
+extern gl_list_node_t gl_list_search_from (gl_list_t list, size_t start_index,
+					   const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX and < END_INDEX.
+   Return its node if found, or NULL if not present in the list.  */
+extern gl_list_node_t gl_list_search_from_to (gl_list_t list,
+					      size_t start_index,
+					      size_t end_index,
+					      const void *elt);
+
+/* Search whether an element is already in the list.
+   Return its position if found, or (size_t)(-1) if not present in the list.  */
+extern size_t gl_list_indexof (gl_list_t list, const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX.
+   Return its position if found, or (size_t)(-1) if not present in the list.  */
+extern size_t gl_list_indexof_from (gl_list_t list, size_t start_index,
+				    const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX and < END_INDEX.
+   Return its position if found, or (size_t)(-1) if not present in the list.  */
+extern size_t gl_list_indexof_from_to (gl_list_t list,
+				       size_t start_index, size_t end_index,
+				       const void *elt);
+
+/* Add an element as the first element of the list.
+   Return its node.  */
+extern gl_list_node_t gl_list_add_first (gl_list_t list, const void *elt);
+
+/* Add an element as the last element of the list.
+   Return its node.  */
+extern gl_list_node_t gl_list_add_last (gl_list_t list, const void *elt);
+
+/* Add an element before a given element node of the list.
+   Return its node.  */
+extern gl_list_node_t gl_list_add_before (gl_list_t list, gl_list_node_t node,
+					  const void *elt);
+
+/* Add an element after a given element node of the list.
+   Return its node.  */
+extern gl_list_node_t gl_list_add_after (gl_list_t list, gl_list_node_t node,
+					 const void *elt);
+
+/* Add an element add a given position in the list.
+   POSITION must be >= 0 and <= gl_list_size (list).  */
+extern gl_list_node_t gl_list_add_at (gl_list_t list, size_t position,
+				      const void *elt);
+
+/* Remove an element from the list.
+   Return true.  */
+extern bool gl_list_remove_node (gl_list_t list, gl_list_node_t node);
+
+/* Remove an element at a given position from the list.
+   POSITION must be >= 0 and < gl_list_size (list).
+   Return true.  */
+extern bool gl_list_remove_at (gl_list_t list, size_t position);
+
+/* Search and remove an element from the list.
+   Return true if it was found and removed.  */
+extern bool gl_list_remove (gl_list_t list, const void *elt);
+
+/* Free an entire list.
+   (But this call does not free the elements of the list.)  */
+extern void gl_list_free (gl_list_t list);
+
+/* --------------------- gl_list_iterator_t Data Type --------------------- */
+
+/* Functions for iterating through a list.  */
+
+/* Type of an iterator that traverses a list.
+   This is a fixed-size struct, so that creation of an iterator doesn't need
+   memory allocation on the heap.  */
+typedef struct
+{
+  /* For fast dispatch of gl_list_iterator_next.  */
+  const struct gl_list_implementation *vtable;
+  /* For detecting whether the last returned element was removed.  */
+  gl_list_t list;
+  size_t count;
+  /* Other, implementation-private fields.  */
+  void *p; void *q;
+  size_t i; size_t j;
+} gl_list_iterator_t;
+
+/* Create an iterator traversing a list.
+   The list contents must not be modified while the iterator is in use,
+   except for replacing or removing the last returned element.  */
+extern gl_list_iterator_t gl_list_iterator (gl_list_t list);
+
+/* Create an iterator traversing the element with indices i,
+   start_index <= i < end_index, of a list.
+   The list contents must not be modified while the iterator is in use,
+   except for replacing or removing the last returned element.  */
+extern gl_list_iterator_t gl_list_iterator_from_to (gl_list_t list,
+						    size_t start_index,
+						    size_t end_index);
+
+/* If there is a next element, store the next element in *ELTP, store its
+   node in *NODEP if NODEP is non-NULL, advance the iterator and return true.
+   Otherwise, return false.  */
+extern bool gl_list_iterator_next (gl_list_iterator_t *iterator,
+				   const void **eltp, gl_list_node_t *nodep);
+
+/* Free an iterator.  */
+extern void gl_list_iterator_free (gl_list_iterator_t *iterator);
+
+/* ---------------------- Sorted gl_list_t Data Type ---------------------- */
+
+/* The following functions are for lists without duplicates where the
+   order is given by a sort criterion.  */
+
+/* Type of function used to compare two elements.  Same as for qsort().
+   NULL denotes pointer comparison.  */
+typedef int (*gl_listelement_compar_fn) (const void *elt1, const void *elt2);
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Return its node if found, or NULL if not present in the list.
+   If the list contains several copies of ELT, the node of the leftmost one is
+   returned.  */
+extern gl_list_node_t gl_sortedlist_search (gl_list_t list,
+					    gl_listelement_compar_fn compar,
+					    const void *elt);
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Only list elements with indices >= START_INDEX and < END_INDEX are
+   considered; the implementation uses these bounds to minimize the number
+   of COMPAR invocations.
+   Return its node if found, or NULL if not present in the list.
+   If the list contains several copies of ELT, the node of the leftmost one is
+   returned.  */
+extern gl_list_node_t gl_sortedlist_search_from_to (gl_list_t list,
+						    gl_listelement_compar_fn compar,
+						    size_t start_index,
+						    size_t end_index,
+						    const void *elt);
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Return its position if found, or (size_t)(-1) if not present in the list.
+   If the list contains several copies of ELT, the position of the leftmost one
+   is returned.  */
+extern size_t gl_sortedlist_indexof (gl_list_t list,
+				     gl_listelement_compar_fn compar,
+				     const void *elt);
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Only list elements with indices >= START_INDEX and < END_INDEX are
+   considered; the implementation uses these bounds to minimize the number
+   of COMPAR invocations.
+   Return its position if found, or (size_t)(-1) if not present in the list.
+   If the list contains several copies of ELT, the position of the leftmost one
+   is returned.  */
+extern size_t gl_sortedlist_indexof_from_to (gl_list_t list,
+					     gl_listelement_compar_fn compar,
+					     size_t start_index,
+					     size_t end_index,
+					     const void *elt);
+
+/* Add an element at the appropriate position in the list.
+   The list is assumed to be sorted with COMPAR.
+   Return its node.  */
+extern gl_list_node_t gl_sortedlist_add (gl_list_t list,
+					 gl_listelement_compar_fn compar,
+					 const void *elt);
+
+/* Search and remove an element from the list.
+   The list is assumed to be sorted with COMPAR.
+   Return true if it was found and removed.
+   If the list contains several copies of ELT, only the leftmost one is
+   removed.  */
+extern bool gl_sortedlist_remove (gl_list_t list,
+				  gl_listelement_compar_fn compar,
+				  const void *elt);
+
+/* ------------------------ Implementation Details ------------------------ */
+
+struct gl_list_implementation
+{
+  /* gl_list_t functions.  */
+  gl_list_t (*create_empty) (gl_list_implementation_t implementation,
+			     gl_listelement_equals_fn equals_fn,
+			     gl_listelement_hashcode_fn hashcode_fn,
+			     bool allow_duplicates);
+  gl_list_t (*create) (gl_list_implementation_t implementation,
+		       gl_listelement_equals_fn equals_fn,
+		       gl_listelement_hashcode_fn hashcode_fn,
+		       bool allow_duplicates,
+		       size_t count, const void **contents);
+  size_t (*size) (gl_list_t list);
+  const void * (*node_value) (gl_list_t list, gl_list_node_t node);
+  gl_list_node_t (*next_node) (gl_list_t list, gl_list_node_t node);
+  gl_list_node_t (*previous_node) (gl_list_t list, gl_list_node_t node);
+  const void * (*get_at) (gl_list_t list, size_t position);
+  gl_list_node_t (*set_at) (gl_list_t list, size_t position, const void *elt);
+  gl_list_node_t (*search_from_to) (gl_list_t list, size_t start_index,
+				    size_t end_index, const void *elt);
+  size_t (*indexof_from_to) (gl_list_t list, size_t start_index,
+			     size_t end_index, const void *elt);
+  gl_list_node_t (*add_first) (gl_list_t list, const void *elt);
+  gl_list_node_t (*add_last) (gl_list_t list, const void *elt);
+  gl_list_node_t (*add_before) (gl_list_t list, gl_list_node_t node,
+				const void *elt);
+  gl_list_node_t (*add_after) (gl_list_t list, gl_list_node_t node,
+			       const void *elt);
+  gl_list_node_t (*add_at) (gl_list_t list, size_t position,
+			    const void *elt);
+  bool (*remove_node) (gl_list_t list, gl_list_node_t node);
+  bool (*remove_at) (gl_list_t list, size_t position);
+  bool (*remove) (gl_list_t list, const void *elt);
+  void (*list_free) (gl_list_t list);
+  /* gl_list_iterator_t functions.  */
+  gl_list_iterator_t (*iterator) (gl_list_t list);
+  gl_list_iterator_t (*iterator_from_to) (gl_list_t list,
+					  size_t start_index,
+					  size_t end_index);
+  bool (*iterator_next) (gl_list_iterator_t *iterator,
+			 const void **eltp, gl_list_node_t *nodep);
+  void (*iterator_free) (gl_list_iterator_t *iterator);
+  /* Sorted gl_list_t functions.  */
+  gl_list_node_t (*sortedlist_search) (gl_list_t list,
+				       gl_listelement_compar_fn compar,
+				       const void *elt);
+  gl_list_node_t (*sortedlist_search_from_to) (gl_list_t list,
+					       gl_listelement_compar_fn compar,
+					       size_t start_index,
+					       size_t end_index,
+					       const void *elt);
+  size_t (*sortedlist_indexof) (gl_list_t list,
+				gl_listelement_compar_fn compar,
+				const void *elt);
+  size_t (*sortedlist_indexof_from_to) (gl_list_t list,
+					gl_listelement_compar_fn compar,
+					size_t start_index, size_t end_index,
+					const void *elt);
+  gl_list_node_t (*sortedlist_add) (gl_list_t list,
+				    gl_listelement_compar_fn compar,
+				    const void *elt);
+  bool (*sortedlist_remove) (gl_list_t list,
+			     gl_listelement_compar_fn compar,
+			     const void *elt);
+};
+
+struct gl_list_impl_base
+{
+  const struct gl_list_implementation *vtable;
+  gl_listelement_equals_fn equals_fn;
+  gl_listelement_hashcode_fn hashcode_fn;
+  bool allow_duplicates;
+};
+
+#if HAVE_INLINE
+
+/* Define all functions of this file as inline accesses to the
+   struct gl_list_implementation.
+   Use #define to avoid a warning because of extern vs. static.  */
+
+# define gl_list_create_empty gl_list_create_empty_inline
+static inline gl_list_t
+gl_list_create_empty (gl_list_implementation_t implementation,
+		      gl_listelement_equals_fn equals_fn,
+		      gl_listelement_hashcode_fn hashcode_fn,
+		      bool allow_duplicates)
+{
+  return implementation->create_empty (implementation, equals_fn, hashcode_fn,
+				       allow_duplicates);
+}
+
+# define gl_list_create gl_list_create_inline
+static inline gl_list_t
+gl_list_create (gl_list_implementation_t implementation,
+		gl_listelement_equals_fn equals_fn,
+		gl_listelement_hashcode_fn hashcode_fn,
+		bool allow_duplicates,
+		size_t count, const void **contents)
+{
+  return implementation->create (implementation, equals_fn, hashcode_fn,
+				 allow_duplicates, count, contents);
+}
+
+# define gl_list_size gl_list_size_inline
+static inline size_t
+gl_list_size (gl_list_t list)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->size (list);
+}
+
+# define gl_list_node_value gl_list_node_value_inline
+static inline const void *
+gl_list_node_value (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->node_value (list, node);
+}
+
+# define gl_list_next_node gl_list_next_node_inline
+static inline gl_list_node_t
+gl_list_next_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->next_node (list, node);
+}
+
+# define gl_list_previous_node gl_list_previous_node_inline
+static inline gl_list_node_t
+gl_list_previous_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->previous_node (list, node);
+}
+
+# define gl_list_get_at gl_list_get_at_inline
+static inline const void *
+gl_list_get_at (gl_list_t list, size_t position)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->get_at (list, position);
+}
+
+# define gl_list_set_at gl_list_set_at_inline
+static inline gl_list_node_t
+gl_list_set_at (gl_list_t list, size_t position, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->set_at (list, position, elt);
+}
+
+# define gl_list_search gl_list_search_inline
+static inline gl_list_node_t
+gl_list_search (gl_list_t list, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->search_from_to (list, 0, size, elt);
+}
+
+# define gl_list_search_from gl_list_search_from_inline
+static inline gl_list_node_t
+gl_list_search_from (gl_list_t list, size_t start_index, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->search_from_to (list, start_index, size, elt);
+}
+
+# define gl_list_search_from_to gl_list_search_from_to_inline
+static inline gl_list_node_t
+gl_list_search_from_to (gl_list_t list, size_t start_index, size_t end_index,
+			const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->search_from_to (list, start_index, end_index, elt);
+}
+
+# define gl_list_indexof gl_list_indexof_inline
+static inline size_t
+gl_list_indexof (gl_list_t list, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->indexof_from_to (list, 0, size, elt);
+}
+
+# define gl_list_indexof_from gl_list_indexof_from_inline
+static inline size_t
+gl_list_indexof_from (gl_list_t list, size_t start_index, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->indexof_from_to (list, start_index, size, elt);
+}
+
+# define gl_list_indexof_from_to gl_list_indexof_from_to_inline
+static inline size_t
+gl_list_indexof_from_to (gl_list_t list, size_t start_index, size_t end_index,
+			 const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->indexof_from_to (list, start_index, end_index, elt);
+}
+
+# define gl_list_add_first gl_list_add_first_inline
+static inline gl_list_node_t
+gl_list_add_first (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_first (list, elt);
+}
+
+# define gl_list_add_last gl_list_add_last_inline
+static inline gl_list_node_t
+gl_list_add_last (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_last (list, elt);
+}
+
+# define gl_list_add_before gl_list_add_before_inline
+static inline gl_list_node_t
+gl_list_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_before (list, node, elt);
+}
+
+# define gl_list_add_after gl_list_add_after_inline
+static inline gl_list_node_t
+gl_list_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_after (list, node, elt);
+}
+
+# define gl_list_add_at gl_list_add_at_inline
+static inline gl_list_node_t
+gl_list_add_at (gl_list_t list, size_t position, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->add_at (list, position, elt);
+}
+
+# define gl_list_remove_node gl_list_remove_node_inline
+static inline bool
+gl_list_remove_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->remove_node (list, node);
+}
+
+# define gl_list_remove_at gl_list_remove_at_inline
+static inline bool
+gl_list_remove_at (gl_list_t list, size_t position)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->remove_at (list, position);
+}
+
+# define gl_list_remove gl_list_remove_inline
+static inline bool
+gl_list_remove (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->remove (list, elt);
+}
+
+# define gl_list_free gl_list_free_inline
+static inline void
+gl_list_free (gl_list_t list)
+{
+  ((const struct gl_list_impl_base *) list)->vtable->list_free (list);
+}
+
+# define gl_list_iterator gl_list_iterator_inline
+static inline gl_list_iterator_t
+gl_list_iterator (gl_list_t list)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->iterator (list);
+}
+
+# define gl_list_iterator_from_to gl_list_iterator_from_to_inline
+static inline gl_list_iterator_t
+gl_list_iterator_from_to (gl_list_t list, size_t start_index, size_t end_index)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->iterator_from_to (list, start_index, end_index);
+}
+
+# define gl_list_iterator_next gl_list_iterator_next_inline
+static inline bool
+gl_list_iterator_next (gl_list_iterator_t *iterator,
+		       const void **eltp, gl_list_node_t *nodep)
+{
+  return iterator->vtable->iterator_next (iterator, eltp, nodep);
+}
+
+# define gl_list_iterator_free gl_list_iterator_free_inline
+static inline void
+gl_list_iterator_free (gl_list_iterator_t *iterator)
+{
+  iterator->vtable->iterator_free (iterator);
+}
+
+# define gl_sortedlist_search gl_sortedlist_search_inline
+static inline gl_list_node_t
+gl_sortedlist_search (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_search (list, compar, elt);
+}
+
+# define gl_sortedlist_search_from_to gl_sortedlist_search_from_to_inline
+static inline gl_list_node_t
+gl_sortedlist_search_from_to (gl_list_t list, gl_listelement_compar_fn compar, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_search_from_to (list, compar, start_index, end_index,
+				      elt);
+}
+
+# define gl_sortedlist_indexof gl_sortedlist_indexof_inline
+static inline size_t
+gl_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_indexof (list, compar, elt);
+}
+
+# define gl_sortedlist_indexof_from_to gl_sortedlist_indexof_from_to_inline
+static inline size_t
+gl_sortedlist_indexof_from_to (gl_list_t list, gl_listelement_compar_fn compar, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_indexof_from_to (list, compar, start_index, end_index,
+				       elt);
+}
+
+# define gl_sortedlist_add gl_sortedlist_add_inline
+static inline gl_list_node_t
+gl_sortedlist_add (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_add (list, compar, elt);
+}
+
+# define gl_sortedlist_remove gl_sortedlist_remove_inline
+static inline bool
+gl_sortedlist_remove (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+	 ->sortedlist_remove (list, compar, elt);
+}
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _GL_LIST_H */
diff --git a/src/bin/m4/lib/gl_oset.c b/src/bin/m4/lib/gl_oset.c
new file mode 100644
index 0000000000..83f964e0ce
--- /dev/null
+++ b/src/bin/m4/lib/gl_oset.c
@@ -0,0 +1,94 @@
+/* Abstract ordered set data type.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "gl_oset.h"
+
+#if !HAVE_INLINE
+
+/* Define all functions of this file as inline accesses to the
+   struct gl_list_implementation.
+   Use #define to avoid a warning because of extern vs. static.  */
+
+gl_oset_t
+gl_oset_create_empty (gl_oset_implementation_t implementation,
+		      gl_setelement_compar_fn compar_fn)
+{
+  return implementation->create_empty (implementation, compar_fn);
+}
+
+size_t
+gl_oset_size (gl_oset_t set)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->size (set);
+}
+
+bool
+gl_oset_search (gl_oset_t set, const void *elt)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->search (set, elt);
+}
+
+bool
+gl_oset_search_atleast (gl_oset_t set,
+			gl_setelement_threshold_fn threshold_fn,
+			const void *threshold, const void **eltp)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable
+	 ->search_atleast (set, threshold_fn, threshold, eltp);
+}
+
+bool
+gl_oset_add (gl_oset_t set, const void *elt)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->add (set, elt);
+}
+
+bool
+gl_oset_remove (gl_oset_t set, const void *elt)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->remove (set, elt);
+}
+
+void
+gl_oset_free (gl_oset_t set)
+{
+  ((const struct gl_oset_impl_base *) set)->vtable->oset_free (set);
+}
+
+gl_oset_iterator_t
+gl_oset_iterator (gl_oset_t set)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->iterator (set);
+}
+
+bool
+gl_oset_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
+{
+  return iterator->vtable->iterator_next (iterator, eltp);
+}
+
+void
+gl_oset_iterator_free (gl_oset_iterator_t *iterator)
+{
+  iterator->vtable->iterator_free (iterator);
+}
+
+#endif
diff --git a/src/bin/m4/lib/gl_oset.h b/src/bin/m4/lib/gl_oset.h
new file mode 100644
index 0000000000..fb36aac1cf
--- /dev/null
+++ b/src/bin/m4/lib/gl_oset.h
@@ -0,0 +1,265 @@
+/* Abstract ordered set data type.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GL_OSET_H
+#define _GL_OSET_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* gl_oset is an abstract ordered set data type.  It can contain any number
+   of objects ('void *' or 'const void *' pointers) in the order of a given
+   comparator function.  Duplicates (in the sense of the comparator) are
+   forbidden.
+
+   There are several implementations of this ordered set datatype, optimized
+   for different operations or for memory.  You can start using the simplest
+   ordered set implementation, GL_ARRAY_OSET, and switch to a different
+   implementation later, when you realize which operations are performed
+   the most frequently.  The API of the different implementations is exactly
+   the same; when switching to a different implementation, you only have to
+   change the gl_oset_create call.
+
+   The implementations are:
+     GL_ARRAY_OSET        a growable array
+     GL_AVLTREE_OSET      a binary tree (AVL tree)
+     GL_RBTREE_OSET       a binary tree (red-black tree)
+
+   The memory consumption is asymptotically the same: O(1) for every object
+   in the set.  When looking more closely at the average memory consumed
+   for an object, GL_ARRAY_OSET is the most compact representation, and
+   GL_AVLTREE_OSET, GL_RBTREE_OSET need more memory.
+
+   The guaranteed average performance of the operations is, for a set of
+   n elements:
+
+   Operation                  ARRAY     TREE
+
+   gl_oset_size                O(1)     O(1)
+   gl_oset_add                 O(n)   O(log n)
+   gl_oset_remove              O(n)   O(log n)
+   gl_oset_search            O(log n) O(log n)
+   gl_oset_search_atleast    O(log n) O(log n)
+   gl_oset_iterator            O(1)   O(log n)
+   gl_oset_iterator_next       O(1)   O(log n)
+ */
+
+/* -------------------------- gl_oset_t Data Type -------------------------- */
+
+/* Type of function used to compare two elements.  Same as for qsort().
+   NULL denotes pointer comparison.  */
+typedef int (*gl_setelement_compar_fn) (const void *elt1, const void *elt2);
+
+/* Type of function used to compare an element with a threshold.
+   Return true if the element is greater or equal than the threshold.  */
+typedef bool (*gl_setelement_threshold_fn) (const void *elt, const void *threshold);
+
+struct gl_oset_impl;
+/* Type representing an entire ordered set.  */
+typedef struct gl_oset_impl * gl_oset_t;
+
+struct gl_oset_implementation;
+/* Type representing a ordered set datatype implementation.  */
+typedef const struct gl_oset_implementation * gl_oset_implementation_t;
+
+/* Create an empty set.
+   IMPLEMENTATION is one of GL_ARRAY_OSET, GL_AVLTREE_OSET, GL_RBTREE_OSET.
+   COMPAR_FN is an element comparison function or NULL.  */
+extern gl_oset_t gl_oset_create_empty (gl_oset_implementation_t implementation,
+				       gl_setelement_compar_fn compar_fn);
+
+/* Return the current number of elements in an ordered set.  */
+extern size_t gl_oset_size (gl_oset_t set);
+
+/* Search whether an element is already in the ordered set.
+   Return true if found, or false if not present in the set.  */
+extern bool gl_oset_search (gl_oset_t set, const void *elt);
+
+/* Search the least element in the ordered set that compares greater or equal
+   to the given THRESHOLD.  The representation of the THRESHOLD is defined
+   by the THRESHOLD_FN.
+   Return true and store the found element in *ELTP if found, otherwise return
+   false.  */
+extern bool gl_oset_search_atleast (gl_oset_t set,
+				    gl_setelement_threshold_fn threshold_fn,
+				    const void *threshold,
+				    const void **eltp);
+
+/* Add an element to an ordered set.
+   Return true if it was not already in the set and added.  */
+extern bool gl_oset_add (gl_oset_t set, const void *elt);
+
+/* Remove an element from an ordered set.
+   Return true if it was found and removed.  */
+extern bool gl_oset_remove (gl_oset_t set, const void *elt);
+
+/* Free an entire ordered set.
+   (But this call does not free the elements of the set.)  */
+extern void gl_oset_free (gl_oset_t set);
+
+/* --------------------- gl_oset_iterator_t Data Type --------------------- */
+
+/* Functions for iterating through an ordered set.  */
+
+/* Type of an iterator that traverses an ordered set.
+   This is a fixed-size struct, so that creation of an iterator doesn't need
+   memory allocation on the heap.  */
+typedef struct
+{
+  /* For fast dispatch of gl_oset_iterator_next.  */
+  const struct gl_oset_implementation *vtable;
+  /* For detecting whether the last returned element was removed.  */
+  gl_oset_t set;
+  size_t count;
+  /* Other, implementation-private fields.  */
+  void *p; void *q;
+  size_t i; size_t j;
+} gl_oset_iterator_t;
+
+/* Create an iterator traversing an ordered set.
+   The set's contents must not be modified while the iterator is in use,
+   except for removing the last returned element.  */
+extern gl_oset_iterator_t gl_oset_iterator (gl_oset_t set);
+
+/* If there is a next element, store the next element in *ELTP, advance the
+   iterator and return true.  Otherwise, return false.  */
+extern bool gl_oset_iterator_next (gl_oset_iterator_t *iterator,
+				   const void **eltp);
+
+/* Free an iterator.  */
+extern void gl_oset_iterator_free (gl_oset_iterator_t *iterator);
+
+/* ------------------------ Implementation Details ------------------------ */
+
+struct gl_oset_implementation
+{
+  /* gl_oset_t functions.  */
+  gl_oset_t (*create_empty) (gl_oset_implementation_t implementation,
+			     gl_setelement_compar_fn compar_fn);
+  size_t (*size) (gl_oset_t set);
+  bool (*search) (gl_oset_t set, const void *elt);
+  bool (*search_atleast) (gl_oset_t set,
+			  gl_setelement_threshold_fn threshold_fn,
+			  const void *threshold, const void **eltp);
+  bool (*add) (gl_oset_t set, const void *elt);
+  bool (*remove) (gl_oset_t set, const void *elt);
+  void (*oset_free) (gl_oset_t set);
+  /* gl_oset_iterator_t functions.  */
+  gl_oset_iterator_t (*iterator) (gl_oset_t set);
+  bool (*iterator_next) (gl_oset_iterator_t *iterator, const void **eltp);
+  void (*iterator_free) (gl_oset_iterator_t *iterator);
+};
+
+struct gl_oset_impl_base
+{
+  const struct gl_oset_implementation *vtable;
+  gl_setelement_compar_fn compar_fn;
+};
+
+#if HAVE_INLINE
+
+/* Define all functions of this file as inline accesses to the
+   struct gl_oset_implementation.
+   Use #define to avoid a warning because of extern vs. static.  */
+
+# define gl_oset_create_empty gl_oset_create_empty_inline
+static inline gl_oset_t
+gl_oset_create_empty (gl_oset_implementation_t implementation,
+		      gl_setelement_compar_fn compar_fn)
+{
+  return implementation->create_empty (implementation, compar_fn);
+}
+
+# define gl_oset_size gl_oset_size_inline
+static inline size_t
+gl_oset_size (gl_oset_t set)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->size (set);
+}
+
+# define gl_oset_search gl_oset_search_inline
+static inline bool
+gl_oset_search (gl_oset_t set, const void *elt)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->search (set, elt);
+}
+
+# define gl_oset_search_atleast gl_oset_search_atleast_inline
+static inline bool
+gl_oset_search_atleast (gl_oset_t set,
+			gl_setelement_threshold_fn threshold_fn,
+			const void *threshold, const void **eltp)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable
+	 ->search_atleast (set, threshold_fn, threshold, eltp);
+}
+
+# define gl_oset_add gl_oset_add_inline
+static inline bool
+gl_oset_add (gl_oset_t set, const void *elt)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->add (set, elt);
+}
+
+# define gl_oset_remove gl_oset_remove_inline
+static inline bool
+gl_oset_remove (gl_oset_t set, const void *elt)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->remove (set, elt);
+}
+
+# define gl_oset_free gl_oset_free_inline
+static inline void
+gl_oset_free (gl_oset_t set)
+{
+  ((const struct gl_oset_impl_base *) set)->vtable->oset_free (set);
+}
+
+# define gl_oset_iterator gl_oset_iterator_inline
+static inline gl_oset_iterator_t
+gl_oset_iterator (gl_oset_t set)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable->iterator (set);
+}
+
+# define gl_oset_iterator_next gl_oset_iterator_next_inline
+static inline bool
+gl_oset_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
+{
+  return iterator->vtable->iterator_next (iterator, eltp);
+}
+
+# define gl_oset_iterator_free gl_oset_iterator_free_inline
+static inline void
+gl_oset_iterator_free (gl_oset_iterator_t *iterator)
+{
+  iterator->vtable->iterator_free (iterator);
+}
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _GL_OSET_H */
diff --git a/src/bin/m4/lib/malloc.c b/src/bin/m4/lib/malloc.c
new file mode 100644
index 0000000000..d4dae3e182
--- /dev/null
+++ b/src/bin/m4/lib/malloc.c
@@ -0,0 +1,35 @@
+/* malloc() function that is glibc compatible.
+
+   Copyright (C) 1997, 1998, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* written by Jim Meyering */
+
+#include <config.h>
+#undef malloc
+
+#include <stdlib.h>
+
+/* Allocate an N-byte block of memory from the heap.
+   If N is zero, allocate a 1-byte block.  */
+
+void *
+rpl_malloc (size_t n)
+{
+  if (n == 0)
+    n = 1;
+  return malloc (n);
+}
diff --git a/src/bin/m4/lib/mbchar.c b/src/bin/m4/lib/mbchar.c
new file mode 100644
index 0000000000..95373f58ba
--- /dev/null
+++ b/src/bin/m4/lib/mbchar.c
@@ -0,0 +1,36 @@
+/* Copyright (C) 2001, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+
+#include <config.h>
+
+#include <limits.h>
+
+#include "mbchar.h"
+
+#if IS_BASIC_ASCII
+
+/* Bit table of characters in the ISO C "basic character set".  */
+const unsigned int is_basic_table [UCHAR_MAX / 32 + 1] =
+{
+  0x00001a00,		/* '\t' '\v' '\f' */
+  0xffffffef,		/* ' '...'#' '%'...'?' */
+  0xfffffffe,		/* 'A'...'Z' '[' '\\' ']' '^' '_' */
+  0x7ffffffe		/* 'a'...'z' '{' '|' '}' '~' */
+  /* The remaining bits are 0.  */
+};
+
+#endif /* IS_BASIC_ASCII */
diff --git a/src/bin/m4/lib/mbchar.h b/src/bin/m4/lib/mbchar.h
new file mode 100644
index 0000000000..a0c2cdcb99
--- /dev/null
+++ b/src/bin/m4/lib/mbchar.h
@@ -0,0 +1,478 @@
+/* Multibyte character data type.
+   Copyright (C) 2001, 2005-2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>.  */
+
+/* A multibyte character is a short subsequence of a char* string,
+   representing a single wide character.
+
+   We use multibyte characters instead of wide characters because of
+   the following goals:
+   1) correct multibyte handling, i.e. operate according to the LC_CTYPE
+      locale,
+   2) ease of maintenance, i.e. the maintainer needs not know all details
+      of the ISO C 99 standard,
+   3) don't fail grossly if the input is not in the encoding set by the
+      locale, because often different encodings are in use in the same
+      countries (ISO-8859-1/UTF-8, EUC-JP/Shift_JIS, ...),
+   4) fast in the case of ASCII characters,
+   5) portability, i.e. don't make unportable assumptions about wchar_t.
+
+   Multibyte characters are only accessed through the mb* macros.
+
+   mb_ptr (mbc)
+     return a pointer to the beginning of the multibyte sequence.
+
+   mb_len (mbc)
+     returns the number of bytes occupied by the multibyte sequence.
+     Always > 0.
+
+   mb_iseq (mbc, sc)
+     returns true if mbc is the standard ASCII character sc.
+
+   mb_isnul (mbc)
+     returns true if mbc is the nul character.
+
+   mb_cmp (mbc1, mbc2)
+     returns a positive, zero, or negative value depending on whether mbc1
+     sorts after, same or before mbc2.
+
+   mb_casecmp (mbc1, mbc2)
+     returns a positive, zero, or negative value depending on whether mbc1
+     sorts after, same or before mbc2, modulo upper/lowercase conversion.
+
+   mb_equal (mbc1, mbc2)
+     returns true if mbc1 and mbc2 are equal.
+
+   mb_caseequal (mbc1, mbc2)
+     returns true if mbc1 and mbc2 are equal modulo upper/lowercase conversion.
+
+   mb_isalnum (mbc)
+     returns true if mbc is alphanumeric.
+
+   mb_isalpha (mbc)
+     returns true if mbc is alphabetic.
+
+   mb_isascii(mbc)
+     returns true if mbc is plain ASCII.
+
+   mb_isblank (mbc)
+     returns true if mbc is a blank.
+
+   mb_iscntrl (mbc)
+     returns true if mbc is a control character.
+
+   mb_isdigit (mbc)
+     returns true if mbc is a decimal digit.
+
+   mb_isgraph (mbc)
+     returns true if mbc is a graphic character.
+
+   mb_islower (mbc)
+     returns true if mbc is lowercase.
+
+   mb_isprint (mbc)
+     returns true if mbc is a printable character.
+
+   mb_ispunct (mbc)
+     returns true if mbc is a punctuation character.
+
+   mb_isspace (mbc)
+     returns true if mbc is a space character.
+
+   mb_isupper (mbc)
+     returns true if mbc is uppercase.
+
+   mb_isxdigit (mbc)
+     returns true if mbc is a hexadecimal digit.
+
+   mb_width (mbc)
+     returns the number of columns on the output device occupied by mbc.
+     Always >= 0.
+
+   mb_putc (mbc, stream)
+     outputs mbc on stream, a byte oriented FILE stream opened for output.
+
+   mb_setascii (&mbc, sc)
+     assigns the standard ASCII character sc to mbc.
+
+   mb_copy (&destmbc, &srcmbc)
+     copies srcmbc to destmbc.
+
+   Here are the function prototypes of the macros.
+
+   extern const char *	mb_ptr (const mbchar_t mbc);
+   extern size_t	mb_len (const mbchar_t mbc);
+   extern bool		mb_iseq (const mbchar_t mbc, char sc);
+   extern bool		mb_isnul (const mbchar_t mbc);
+   extern int		mb_cmp (const mbchar_t mbc1, const mbchar_t mbc2);
+   extern int		mb_casecmp (const mbchar_t mbc1, const mbchar_t mbc2);
+   extern bool		mb_equal (const mbchar_t mbc1, const mbchar_t mbc2);
+   extern bool		mb_caseequal (const mbchar_t mbc1, const mbchar_t mbc2);
+   extern bool		mb_isalnum (const mbchar_t mbc);
+   extern bool		mb_isalpha (const mbchar_t mbc);
+   extern bool		mb_isascii (const mbchar_t mbc);
+   extern bool		mb_isblank (const mbchar_t mbc);
+   extern bool		mb_iscntrl (const mbchar_t mbc);
+   extern bool		mb_isdigit (const mbchar_t mbc);
+   extern bool		mb_isgraph (const mbchar_t mbc);
+   extern bool		mb_islower (const mbchar_t mbc);
+   extern bool		mb_isprint (const mbchar_t mbc);
+   extern bool		mb_ispunct (const mbchar_t mbc);
+   extern bool		mb_isspace (const mbchar_t mbc);
+   extern bool		mb_isupper (const mbchar_t mbc);
+   extern bool		mb_isxdigit (const mbchar_t mbc);
+   extern int		mb_width (const mbchar_t mbc);
+   extern void		mb_putc (const mbchar_t mbc, FILE *stream);
+   extern void          mb_setascii (mbchar_t *new, char sc);
+   extern void		mb_copy (mbchar_t *new, const mbchar_t *old);
+ */
+
+#ifndef _MBCHAR_H
+#define _MBCHAR_H 1
+
+#include <stdbool.h>
+#include <string.h>
+
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
+   <wchar.h>.  */
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+
+/* BeOS 5 has the functions but no <wctype.h>.  */
+#if HAVE_WCTYPE_H
+# include <wctype.h>
+#endif
+/* FreeBSD 4.4 to 4.11 has <wctype.h> but lacks the functions.
+   Assume all 12 functions are implemented the same way, or not at all.  */
+#if !defined iswalnum && !HAVE_ISWCNTRL
+static inline int
+iswalnum (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? (wc >= '0' && wc <= '9') || ((wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'Z')
+	  : 0);
+}
+# define iswalnum iswalnum
+#endif
+#if !defined iswalpha && !HAVE_ISWCNTRL
+static inline int
+iswalpha (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? (wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'Z'
+	  : 0);
+}
+# define iswalpha iswalpha
+#endif
+#if !defined iswblank && !HAVE_ISWCNTRL
+static inline int
+iswblank (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? wc == ' ' || wc == '\t'
+	  : 0);
+}
+# define iswblank iswblank
+#endif
+#if !defined iswcntrl && !HAVE_ISWCNTRL
+static inline int
+iswcntrl (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? (wc & ~0x1f) == 0 || wc == 0x7f
+	  : 0);
+}
+# define iswcntrl iswcntrl
+#endif
+#if !defined iswdigit && !HAVE_ISWCNTRL
+static inline int
+iswdigit (wint_t wc)
+{
+  return (wc >= '0' && wc <= '9');
+}
+# define iswdigit iswdigit
+#endif
+#if !defined iswgraph && !HAVE_ISWCNTRL
+static inline int
+iswgraph (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? wc >= '!' && wc <= '~'
+	  : 1);
+}
+# define iswgraph iswgraph
+#endif
+#if !defined iswlower && !HAVE_ISWCNTRL
+static inline int
+iswlower (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? wc >= 'a' && wc <= 'z'
+	  : 0);
+}
+# define iswlower iswlower
+#endif
+#if !defined iswprint && !HAVE_ISWCNTRL
+static inline int
+iswprint (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? wc >= ' ' && wc <= '~'
+	  : 1);
+}
+# define iswprint iswprint
+#endif
+#if !defined iswpunct && !HAVE_ISWCNTRL
+static inline int
+iswpunct (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? wc >= '!' && wc <= '~'
+	    && !((wc >= '0' && wc <= '9')
+		 || ((wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'Z'))
+	  : 1);
+}
+# define iswpunct iswpunct
+#endif
+#if !defined iswspace && !HAVE_ISWCNTRL
+static inline int
+iswspace (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? wc == ' ' || wc == '\t'
+	    || wc == '\n' || wc == '\v' || wc == '\f' || wc == '\r'
+	  : 0);
+}
+# define iswspace iswspace
+#endif
+#if !defined iswupper && !HAVE_ISWCNTRL
+static inline int
+iswupper (wint_t wc)
+{
+  return (wc >= 0 && wc < 128
+	  ? wc >= 'A' && wc <= 'Z'
+	  : 0);
+}
+# define iswupper iswupper
+#endif
+#if !defined iswxdigit && !HAVE_ISWCNTRL
+static inline int
+iswxdigit (wint_t wc)
+{
+  return (wc >= '0' && wc <= '9') || ((wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'F');
+}
+# define iswxdigit iswxdigit
+#endif
+
+#include "wcwidth.h"
+
+#define MBCHAR_BUF_SIZE 24
+
+struct mbchar
+{
+  const char *ptr;	/* pointer to current character */
+  size_t bytes;		/* number of bytes of current character, > 0 */
+  bool wc_valid;	/* true if wc is a valid wide character */
+  wchar_t wc;		/* if wc_valid: the current character */
+  char buf[MBCHAR_BUF_SIZE]; /* room for the bytes, used for file input only */
+};
+
+/* EOF (not a real character) is represented with bytes = 0 and
+   wc_valid = false.  */
+
+typedef struct mbchar mbchar_t;
+
+/* Access the current character.  */
+#define mb_ptr(mbc) ((mbc).ptr)
+#define mb_len(mbc) ((mbc).bytes)
+
+/* Comparison of characters.  */
+#define mb_iseq(mbc, sc) ((mbc).wc_valid && (mbc).wc == (sc))
+#define mb_isnul(mbc) ((mbc).wc_valid && (mbc).wc == 0)
+#define mb_cmp(mbc1, mbc2) \
+  ((mbc1).wc_valid							\
+   ? ((mbc2).wc_valid							\
+      ? (int) (mbc1).wc - (int) (mbc2).wc				\
+      : -1)								\
+   : ((mbc2).wc_valid							\
+      ? 1								\
+      : (mbc1).bytes == (mbc2).bytes					\
+        ? memcmp ((mbc1).ptr, (mbc2).ptr, (mbc1).bytes)			\
+        : (mbc1).bytes < (mbc2).bytes					\
+          ? (memcmp ((mbc1).ptr, (mbc2).ptr, (mbc1).bytes) > 0 ? 1 : -1) \
+          : (memcmp ((mbc1).ptr, (mbc2).ptr, (mbc2).bytes) >= 0 ? 1 : -1)))
+#define mb_casecmp(mbc1, mbc2) \
+  ((mbc1).wc_valid							\
+   ? ((mbc2).wc_valid							\
+      ? (int) towlower ((mbc1).wc) - (int) towlower ((mbc2).wc)		\
+      : -1)								\
+   : ((mbc2).wc_valid							\
+      ? 1								\
+      : (mbc1).bytes == (mbc2).bytes					\
+        ? memcmp ((mbc1).ptr, (mbc2).ptr, (mbc1).bytes)			\
+        : (mbc1).bytes < (mbc2).bytes					\
+          ? (memcmp ((mbc1).ptr, (mbc2).ptr, (mbc1).bytes) > 0 ? 1 : -1) \
+          : (memcmp ((mbc1).ptr, (mbc2).ptr, (mbc2).bytes) >= 0 ? 1 : -1)))
+#define mb_equal(mbc1, mbc2) \
+  ((mbc1).wc_valid && (mbc2).wc_valid					\
+   ? (mbc1).wc == (mbc2).wc						\
+   : (mbc1).bytes == (mbc2).bytes					\
+     && memcmp ((mbc1).ptr, (mbc2).ptr, (mbc1).bytes) == 0)
+#define mb_caseequal(mbc1, mbc2) \
+  ((mbc1).wc_valid && (mbc2).wc_valid					\
+   ? towlower ((mbc1).wc) == towlower ((mbc2).wc)			\
+   : (mbc1).bytes == (mbc2).bytes					\
+     && memcmp ((mbc1).ptr, (mbc2).ptr, (mbc1).bytes) == 0)
+
+/* <ctype.h>, <wctype.h> classification.  */
+#define mb_isascii(mbc) \
+  ((mbc).wc_valid && (mbc).wc >= 0 && (mbc).wc <= 127)
+#define mb_isalnum(mbc) ((mbc).wc_valid && iswalnum ((mbc).wc))
+#define mb_isalpha(mbc) ((mbc).wc_valid && iswalpha ((mbc).wc))
+#define mb_isblank(mbc) ((mbc).wc_valid && iswblank ((mbc).wc))
+#define mb_iscntrl(mbc) ((mbc).wc_valid && iswcntrl ((mbc).wc))
+#define mb_isdigit(mbc) ((mbc).wc_valid && iswdigit ((mbc).wc))
+#define mb_isgraph(mbc) ((mbc).wc_valid && iswgraph ((mbc).wc))
+#define mb_islower(mbc) ((mbc).wc_valid && iswlower ((mbc).wc))
+#define mb_isprint(mbc) ((mbc).wc_valid && iswprint ((mbc).wc))
+#define mb_ispunct(mbc) ((mbc).wc_valid && iswpunct ((mbc).wc))
+#define mb_isspace(mbc) ((mbc).wc_valid && iswspace ((mbc).wc))
+#define mb_isupper(mbc) ((mbc).wc_valid && iswupper ((mbc).wc))
+#define mb_isxdigit(mbc) ((mbc).wc_valid && iswxdigit ((mbc).wc))
+
+/* Extra <wchar.h> function.  */
+
+/* Unprintable characters appear as a small box of width 1.  */
+#define MB_UNPRINTABLE_WIDTH 1
+
+static inline int
+mb_width_aux (wint_t wc)
+{
+  int w = wcwidth (wc);
+  /* For unprintable characters, arbitrarily return 0 for control characters
+     and MB_UNPRINTABLE_WIDTH otherwise.  */
+  return (w >= 0 ? w : iswcntrl (wc) ? 0 : MB_UNPRINTABLE_WIDTH);
+}
+
+#define mb_width(mbc) \
+  ((mbc).wc_valid ? mb_width_aux ((mbc).wc) : MB_UNPRINTABLE_WIDTH)
+
+/* Output.  */
+#define mb_putc(mbc, stream)  fwrite ((mbc).ptr, 1, (mbc).bytes, (stream))
+
+/* Assignment.  */
+#define mb_setascii(mbc, sc) \
+  ((mbc)->ptr = (mbc)->buf, (mbc)->bytes = 1, (mbc)->wc_valid = 1, \
+   (mbc)->wc = (mbc)->buf[0] = (sc))
+
+/* Copying a character.  */
+static inline void
+mb_copy (mbchar_t *new_mbc, const mbchar_t *old_mbc)
+{
+  if (old_mbc->ptr == &old_mbc->buf[0])
+    {
+      memcpy (&new_mbc->buf[0], &old_mbc->buf[0], old_mbc->bytes);
+      new_mbc->ptr = &new_mbc->buf[0];
+    }
+  else
+    new_mbc->ptr = old_mbc->ptr;
+  new_mbc->bytes = old_mbc->bytes;
+  if ((new_mbc->wc_valid = old_mbc->wc_valid))
+    new_mbc->wc = old_mbc->wc;
+}
+
+
+/* is_basic(c) tests whether the single-byte character c is in the
+   ISO C "basic character set".
+   This is a convenience function, and is in this file only to share code
+   between mbiter_multi.h and mbfile_multi.h.  */
+#if (' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
+    && ('%' == 37) && ('&' == 38) && ('\'' == 39) && ('(' == 40) \
+    && (')' == 41) && ('*' == 42) && ('+' == 43) && (',' == 44) \
+    && ('-' == 45) && ('.' == 46) && ('/' == 47) && ('0' == 48) \
+    && ('1' == 49) && ('2' == 50) && ('3' == 51) && ('4' == 52) \
+    && ('5' == 53) && ('6' == 54) && ('7' == 55) && ('8' == 56) \
+    && ('9' == 57) && (':' == 58) && (';' == 59) && ('<' == 60) \
+    && ('=' == 61) && ('>' == 62) && ('?' == 63) && ('A' == 65) \
+    && ('B' == 66) && ('C' == 67) && ('D' == 68) && ('E' == 69) \
+    && ('F' == 70) && ('G' == 71) && ('H' == 72) && ('I' == 73) \
+    && ('J' == 74) && ('K' == 75) && ('L' == 76) && ('M' == 77) \
+    && ('N' == 78) && ('O' == 79) && ('P' == 80) && ('Q' == 81) \
+    && ('R' == 82) && ('S' == 83) && ('T' == 84) && ('U' == 85) \
+    && ('V' == 86) && ('W' == 87) && ('X' == 88) && ('Y' == 89) \
+    && ('Z' == 90) && ('[' == 91) && ('\\' == 92) && (']' == 93) \
+    && ('^' == 94) && ('_' == 95) && ('a' == 97) && ('b' == 98) \
+    && ('c' == 99) && ('d' == 100) && ('e' == 101) && ('f' == 102) \
+    && ('g' == 103) && ('h' == 104) && ('i' == 105) && ('j' == 106) \
+    && ('k' == 107) && ('l' == 108) && ('m' == 109) && ('n' == 110) \
+    && ('o' == 111) && ('p' == 112) && ('q' == 113) && ('r' == 114) \
+    && ('s' == 115) && ('t' == 116) && ('u' == 117) && ('v' == 118) \
+    && ('w' == 119) && ('x' == 120) && ('y' == 121) && ('z' == 122) \
+    && ('{' == 123) && ('|' == 124) && ('}' == 125) && ('~' == 126)
+/* The character set is ISO-646, not EBCDIC. */
+# define IS_BASIC_ASCII 1
+
+extern const unsigned int is_basic_table[];
+
+static inline bool
+is_basic (char c)
+{
+  return (is_basic_table [(unsigned char) c >> 5] >> ((unsigned char) c & 31))
+	 & 1;
+}
+
+#else
+
+static inline bool
+is_basic (char c)
+{
+  switch (c)
+    {
+    case '\t': case '\v': case '\f':
+    case ' ': case '!': case '"': case '#': case '%':
+    case '&': case '\'': case '(': case ')': case '*':
+    case '+': case ',': case '-': case '.': case '/':
+    case '0': case '1': case '2': case '3': case '4':
+    case '5': case '6': case '7': case '8': case '9':
+    case ':': case ';': case '<': case '=': case '>':
+    case '?':
+    case 'A': case 'B': case 'C': case 'D': case 'E':
+    case 'F': case 'G': case 'H': case 'I': case 'J':
+    case 'K': case 'L': case 'M': case 'N': case 'O':
+    case 'P': case 'Q': case 'R': case 'S': case 'T':
+    case 'U': case 'V': case 'W': case 'X': case 'Y':
+    case 'Z':
+    case '[': case '\\': case ']': case '^': case '_':
+    case 'a': case 'b': case 'c': case 'd': case 'e':
+    case 'f': case 'g': case 'h': case 'i': case 'j':
+    case 'k': case 'l': case 'm': case 'n': case 'o':
+    case 'p': case 'q': case 'r': case 's': case 't':
+    case 'u': case 'v': case 'w': case 'x': case 'y':
+    case 'z': case '{': case '|': case '}': case '~':
+      return 1;
+    default:
+      return 0;
+    }
+}
+
+#endif
+
+#endif /* _MBCHAR_H */
diff --git a/src/bin/m4/lib/mbuiter.h b/src/bin/m4/lib/mbuiter.h
new file mode 100644
index 0000000000..9da3a6c79c
--- /dev/null
+++ b/src/bin/m4/lib/mbuiter.h
@@ -0,0 +1,203 @@
+/* Iterating through multibyte strings: macros for multi-byte encodings.
+   Copyright (C) 2001, 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>.  */
+
+/* The macros in this file implement forward iteration through a
+   multi-byte string, without knowing its length a-priori.
+
+   With these macros, an iteration loop that looks like
+
+      char *iter;
+      for (iter = buf; *iter != '\0'; iter++)
+        {
+          do_something (*iter);
+        }
+
+   becomes
+
+      mbui_iterator_t iter;
+      for (mbui_init (iter, buf); mbui_avail (iter); mbui_advance (iter))
+        {
+          do_something (mbui_cur_ptr (iter), mb_len (mbui_cur (iter)));
+        }
+
+   The benefit of these macros over plain use of mbrtowc is:
+   - Handling of invalid multibyte sequences is possible without
+     making the code more complicated, while still preserving the
+     invalid multibyte sequences.
+
+   Compared to mbiter.h, the macros here don't need to know the string's
+   length a-priori.  The downside is that at each step, the look-ahead
+   that guards against overrunning the terminating '\0' is more expensive.
+   The mbui_* macros are therefore suitable when there is a high probability
+   that only the first few multibyte characters need to be inspected.
+   Whereas the mbi_* macros are better if usually the iteration runs
+   through the entire string.
+
+   mbui_iterator_t
+     is a type usable for variable declarations.
+
+   mbui_init (iter, startptr)
+     initializes the iterator, starting at startptr.
+
+   mbui_avail (iter)
+     returns true if there are more multibyte chracters available before
+     the end of string is reached. In this case, mbui_cur (iter) is
+     initialized to the next multibyte chracter.
+
+   mbui_advance (iter)
+     advances the iterator by one multibyte character.
+
+   mbui_cur (iter)
+     returns the current multibyte character, of type mbchar_t.  All the
+     macros defined in mbchar.h can be used on it.
+
+   mbui_cur_ptr (iter)
+     return a pointer to the beginning of the current multibyte character.
+
+   mbui_reloc (iter, ptrdiff)
+     relocates iterator when the string is moved by ptrdiff bytes.
+
+   Here are the function prototypes of the macros.
+
+   extern void		mbui_init (mbui_iterator_t iter, const char *startptr);
+   extern bool		mbui_avail (mbui_iterator_t iter);
+   extern void		mbui_advance (mbui_iterator_t iter);
+   extern mbchar_t	mbui_cur (mbui_iterator_t iter);
+   extern const char *	mbui_cur_ptr (mbui_iterator_t iter);
+   extern void		mbui_reloc (mbui_iterator_t iter, ptrdiff_t ptrdiff);
+ */
+
+#ifndef _MBUITER_H
+#define _MBUITER_H 1
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
+   <wchar.h>.  */
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+
+#include "mbchar.h"
+#include "strnlen1.h"
+
+struct mbuiter_multi
+{
+  bool in_shift;	/* true if next byte may not be interpreted as ASCII */
+  mbstate_t state;	/* if in_shift: current shift state */
+  bool next_done;	/* true if mbui_avail has already filled the following */
+  struct mbchar cur;	/* the current character:
+	const char *cur.ptr		pointer to current character
+	The following are only valid after mbui_avail.
+	size_t cur.bytes		number of bytes of current character
+	bool cur.wc_valid		true if wc is a valid wide character
+	wchar_t cur.wc			if wc_valid: the current character
+	*/
+};
+
+static inline void
+mbuiter_multi_next (struct mbuiter_multi *iter)
+{
+  if (iter->next_done)
+    return;
+  if (iter->in_shift)
+    goto with_shift;
+  /* Handle most ASCII characters quickly, without calling mbrtowc().  */
+  if (is_basic (*iter->cur.ptr))
+    {
+      /* These characters are part of the basic character set.  ISO C 99
+	 guarantees that their wide character code is identical to their
+	 char code.  */
+      iter->cur.bytes = 1;
+      iter->cur.wc = *iter->cur.ptr;
+      iter->cur.wc_valid = true;
+    }
+  else
+    {
+      assert (mbsinit (&iter->state));
+      iter->in_shift = true;
+    with_shift:
+      iter->cur.bytes = mbrtowc (&iter->cur.wc, iter->cur.ptr,
+				 strnlen1 (iter->cur.ptr, MB_CUR_MAX),
+				 &iter->state);
+      if (iter->cur.bytes == (size_t) -1)
+	{
+	  /* An invalid multibyte sequence was encountered.  */
+	  iter->cur.bytes = 1;
+	  iter->cur.wc_valid = false;
+	  /* Whether to set iter->in_shift = false and reset iter->state
+	     or not is not very important; the string is bogus anyway.  */
+	}
+      else if (iter->cur.bytes == (size_t) -2)
+	{
+	  /* An incomplete multibyte character at the end.  */
+	  iter->cur.bytes = strlen (iter->cur.ptr);
+	  iter->cur.wc_valid = false;
+	  /* Whether to set iter->in_shift = false and reset iter->state
+	     or not is not important; the string end is reached anyway.  */
+	}
+      else
+	{
+	  if (iter->cur.bytes == 0)
+	    {
+	      /* A null wide character was encountered.  */
+	      iter->cur.bytes = 1;
+	      assert (*iter->cur.ptr == '\0');
+	      assert (iter->cur.wc == 0);
+	    }
+	  iter->cur.wc_valid = true;
+
+	  /* When in the initial state, we can go back treating ASCII
+	     characters more quickly.  */
+	  if (mbsinit (&iter->state))
+	    iter->in_shift = false;
+	}
+    }
+  iter->next_done = true;
+}
+
+static inline void
+mbuiter_multi_reloc (struct mbuiter_multi *iter, ptrdiff_t ptrdiff)
+{
+  iter->cur.ptr += ptrdiff;
+}
+
+/* Iteration macros.  */
+typedef struct mbuiter_multi mbui_iterator_t;
+#define mbui_init(iter, startptr) \
+  ((iter).cur.ptr = (startptr), \
+   (iter).in_shift = false, memset (&(iter).state, '\0', sizeof (mbstate_t)), \
+   (iter).next_done = false)
+#define mbui_avail(iter) \
+  (mbuiter_multi_next (&(iter)), !mb_isnul ((iter).cur))
+#define mbui_advance(iter) \
+  ((iter).cur.ptr += (iter).cur.bytes, (iter).next_done = false)
+
+/* Access to the current character.  */
+#define mbui_cur(iter) (iter).cur
+#define mbui_cur_ptr(iter) (iter).cur.ptr
+
+/* Relocation.  */
+#define mbui_reloc(iter, ptrdiff) mbuiter_multi_reloc (&iter, ptrdiff)
+
+#endif /* _MBUITER_H */
diff --git a/src/bin/m4/lib/memchr.c b/src/bin/m4/lib/memchr.c
new file mode 100644
index 0000000000..d44ad6deb5
--- /dev/null
+++ b/src/bin/m4/lib/memchr.c
@@ -0,0 +1,201 @@
+/* Copyright (C) 1991, 1993, 1996, 1997, 1999, 2000, 2003, 2004, 2006 Free
+   Software Foundation, Inc.
+
+   Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
+   with help from Dan Sahlin (dan@sics.se) and
+   commentary by Jim Blandy (jimb@ai.mit.edu);
+   adaptation to memchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
+   and implemented by Roland McGrath (roland@ai.mit.edu).
+
+NOTE: The canonical source of this file is maintained with the GNU C Library.
+Bugs can be reported to bug-glibc@prep.ai.mit.edu.
+
+This program is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software Foundation,
+Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _LIBC
+# include <config.h>
+#endif
+
+#include <string.h>
+
+#include <stddef.h>
+
+#if defined _LIBC
+# include <memcopy.h>
+#else
+# define reg_char char
+#endif
+
+#include <limits.h>
+
+#if HAVE_BP_SYM_H || defined _LIBC
+# include <bp-sym.h>
+#else
+# define BP_SYM(sym) sym
+#endif
+
+#undef memchr
+#undef __memchr
+
+/* Search no more than N bytes of S for C.  */
+void *
+__memchr (void const *s, int c_in, size_t n)
+{
+  const unsigned char *char_ptr;
+  const unsigned long int *longword_ptr;
+  unsigned long int longword, magic_bits, charmask;
+  unsigned reg_char c;
+  int i;
+
+  c = (unsigned char) c_in;
+
+  /* Handle the first few characters by reading one character at a time.
+     Do this until CHAR_PTR is aligned on a longword boundary.  */
+  for (char_ptr = (const unsigned char *) s;
+       n > 0 && (size_t) char_ptr % sizeof longword != 0;
+       --n, ++char_ptr)
+    if (*char_ptr == c)
+      return (void *) char_ptr;
+
+  /* All these elucidatory comments refer to 4-byte longwords,
+     but the theory applies equally well to any size longwords.  */
+
+  longword_ptr = (const unsigned long int *) char_ptr;
+
+  /* Bits 31, 24, 16, and 8 of this number are zero.  Call these bits
+     the "holes."  Note that there is a hole just to the left of
+     each byte, with an extra at the end:
+
+     bits:  01111110 11111110 11111110 11111111
+     bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD
+
+     The 1-bits make sure that carries propagate to the next 0-bit.
+     The 0-bits provide holes for carries to fall into.  */
+
+  /* Set MAGIC_BITS to be this pattern of 1 and 0 bits.
+     Set CHARMASK to be a longword, each of whose bytes is C.  */
+
+  magic_bits = 0xfefefefe;
+  charmask = c | (c << 8);
+  charmask |= charmask << 16;
+#if 0xffffffffU < ULONG_MAX
+  magic_bits |= magic_bits << 32;
+  charmask |= charmask << 32;
+  if (8 < sizeof longword)
+    for (i = 64; i < sizeof longword * 8; i *= 2)
+      {
+	magic_bits |= magic_bits << i;
+	charmask |= charmask << i;
+      }
+#endif
+  magic_bits = (ULONG_MAX >> 1) & (magic_bits | 1);
+
+  /* Instead of the traditional loop which tests each character,
+     we will test a longword at a time.  The tricky part is testing
+     if *any of the four* bytes in the longword in question are zero.  */
+  while (n >= sizeof longword)
+    {
+      /* We tentatively exit the loop if adding MAGIC_BITS to
+	 LONGWORD fails to change any of the hole bits of LONGWORD.
+
+	 1) Is this safe?  Will it catch all the zero bytes?
+	 Suppose there is a byte with all zeros.  Any carry bits
+	 propagating from its left will fall into the hole at its
+	 least significant bit and stop.  Since there will be no
+	 carry from its most significant bit, the LSB of the
+	 byte to the left will be unchanged, and the zero will be
+	 detected.
+
+	 2) Is this worthwhile?  Will it ignore everything except
+	 zero bytes?  Suppose every byte of LONGWORD has a bit set
+	 somewhere.  There will be a carry into bit 8.  If bit 8
+	 is set, this will carry into bit 16.  If bit 8 is clear,
+	 one of bits 9-15 must be set, so there will be a carry
+	 into bit 16.  Similarly, there will be a carry into bit
+	 24.  If one of bits 24-30 is set, there will be a carry
+	 into bit 31, so all of the hole bits will be changed.
+
+	 The one misfire occurs when bits 24-30 are clear and bit
+	 31 is set; in this case, the hole at bit 31 is not
+	 changed.  If we had access to the processor carry flag,
+	 we could close this loophole by putting the fourth hole
+	 at bit 32!
+
+	 So it ignores everything except 128's, when they're aligned
+	 properly.
+
+	 3) But wait!  Aren't we looking for C, not zero?
+	 Good point.  So what we do is XOR LONGWORD with a longword,
+	 each of whose bytes is C.  This turns each byte that is C
+	 into a zero.  */
+
+      longword = *longword_ptr++ ^ charmask;
+
+      /* Add MAGIC_BITS to LONGWORD.  */
+      if ((((longword + magic_bits)
+
+	    /* Set those bits that were unchanged by the addition.  */
+	    ^ ~longword)
+
+	   /* Look at only the hole bits.  If any of the hole bits
+	      are unchanged, most likely one of the bytes was a
+	      zero.  */
+	   & ~magic_bits) != 0)
+	{
+	  /* Which of the bytes was C?  If none of them were, it was
+	     a misfire; continue the search.  */
+
+	  const unsigned char *cp = (const unsigned char *) (longword_ptr - 1);
+
+	  if (cp[0] == c)
+	    return (void *) cp;
+	  if (cp[1] == c)
+	    return (void *) &cp[1];
+	  if (cp[2] == c)
+	    return (void *) &cp[2];
+	  if (cp[3] == c)
+	    return (void *) &cp[3];
+	  if (4 < sizeof longword && cp[4] == c)
+	    return (void *) &cp[4];
+	  if (5 < sizeof longword && cp[5] == c)
+	    return (void *) &cp[5];
+	  if (6 < sizeof longword && cp[6] == c)
+	    return (void *) &cp[6];
+	  if (7 < sizeof longword && cp[7] == c)
+	    return (void *) &cp[7];
+	  if (8 < sizeof longword)
+	    for (i = 8; i < sizeof longword; i++)
+	      if (cp[i] == c)
+		return (void *) &cp[i];
+	}
+
+      n -= sizeof longword;
+    }
+
+  char_ptr = (const unsigned char *) longword_ptr;
+
+  while (n-- > 0)
+    {
+      if (*char_ptr == c)
+	return (void *) char_ptr;
+      else
+	++char_ptr;
+    }
+
+  return 0;
+}
+#ifdef weak_alias
+weak_alias (__memchr, BP_SYM (memchr))
+#endif
diff --git a/src/bin/m4/lib/mkdtemp.c b/src/bin/m4/lib/mkdtemp.c
new file mode 100644
index 0000000000..e916d385b1
--- /dev/null
+++ b/src/bin/m4/lib/mkdtemp.c
@@ -0,0 +1,40 @@
+/* Copyright (C) 1999, 2001-2003, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Extracted from misc/mkdtemp.c.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "mkdtemp.h"
+
+#include "tempname.h"
+#include <stdlib.h>
+
+/* Generate a unique temporary directory from TEMPLATE.
+   The last six characters of TEMPLATE must be "XXXXXX";
+   they are replaced with a string that makes the filename unique.
+   The directory is created, mode 700, and its name is returned.
+   (This function comes from OpenBSD.) */
+char *
+mkdtemp (char *template)
+{
+  if (gen_tempname (template, GT_DIR))
+    return NULL;
+  else
+    return template;
+}
diff --git a/src/bin/m4/lib/mkdtemp.h b/src/bin/m4/lib/mkdtemp.h
new file mode 100644
index 0000000000..6176048019
--- /dev/null
+++ b/src/bin/m4/lib/mkdtemp.h
@@ -0,0 +1,32 @@
+/* Creating a private temporary directory.
+   Copyright (C) 2001-2002 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#if HAVE_MKDTEMP
+
+/* Get mkdtemp() declaration.  */
+#include <stdlib.h>
+
+#else
+
+/* Create a unique temporary directory from TEMPLATE.
+   The last six characters of TEMPLATE must be "XXXXXX";
+   they are replaced with a string that makes the directory name unique.
+   Returns TEMPLATE, or a null pointer if it cannot get a unique name.
+   The directory is created mode 700.  */
+extern char * mkdtemp (char *template);
+
+#endif
diff --git a/src/bin/m4/lib/mkstemp-safer.c b/src/bin/m4/lib/mkstemp-safer.c
new file mode 100644
index 0000000000..c8c5bbd6e4
--- /dev/null
+++ b/src/bin/m4/lib/mkstemp-safer.c
@@ -0,0 +1,35 @@
+/* Invoke mkstemp, but avoid some glitches.
+
+   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <config.h>
+
+#include "stdlib-safer.h"
+
+#include "mkstemp.h"
+#include "unistd-safer.h"
+
+/* Like mkstemp, but do not return STDIN_FILENO, STDOUT_FILENO, or
+   STDERR_FILENO.  */
+
+int
+mkstemp_safer (char *templ)
+{
+  return fd_safer (mkstemp (templ));
+}
diff --git a/src/bin/m4/lib/mkstemp.c b/src/bin/m4/lib/mkstemp.c
new file mode 100644
index 0000000000..34c9e474c0
--- /dev/null
+++ b/src/bin/m4/lib/mkstemp.c
@@ -0,0 +1,42 @@
+/* Copyright (C) 1998, 1999, 2001, 2005, 2006 Free Software Foundation, Inc.
+   This file is derived from the one in the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#if !_LIBC
+# include <config.h>
+# include "mkstemp.h"
+# include "tempname.h"
+# define __gen_tempname gen_tempname
+# define __GT_FILE GT_FILE
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef __GT_FILE
+# define __GT_FILE 0
+#endif
+
+/* Generate a unique temporary file name from TEMPLATE.
+   The last six characters of TEMPLATE must be "XXXXXX";
+   they are replaced with a string that makes the file name unique.
+   Then open the file and return a fd. */
+int
+mkstemp (template)
+     char *template;
+{
+  return __gen_tempname (template, __GT_FILE);
+}
diff --git a/src/bin/m4/lib/mkstemp.h b/src/bin/m4/lib/mkstemp.h
new file mode 100644
index 0000000000..9ed74116d2
--- /dev/null
+++ b/src/bin/m4/lib/mkstemp.h
@@ -0,0 +1,31 @@
+/* Create a unique temporary file.
+
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* written by Jim Meyering */
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#ifdef __MKSTEMP_PREFIX
+# define _GL_CONCAT(x, y) x ## y
+# define _GL_XCONCAT(x, y) _GL_CONCAT (x, y)
+# define __MKSTEMP_ID(y) _GL_XCONCAT (__MKSTEMP_PREFIX, y)
+# undef mkstemp
+# define mkstemp __MKSTEMP_ID (mkstemp)
+int mkstemp (char *);
+#endif
diff --git a/src/bin/m4/lib/obstack.c b/src/bin/m4/lib/obstack.c
new file mode 100644
index 0000000000..5cd0b7a6d0
--- /dev/null
+++ b/src/bin/m4/lib/obstack.c
@@ -0,0 +1,431 @@
+/* obstack.c - subroutines used implicitly by object stack macros
+
+   Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997,
+   1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
+   Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifdef _LIBC
+# include <obstack.h>
+# include <shlib-compat.h>
+#else
+# include <config.h>
+# include "obstack.h"
+#endif
+
+/* NOTE BEFORE MODIFYING THIS FILE: This version number must be
+   incremented whenever callers compiled using an old obstack.h can no
+   longer properly call the functions in this obstack.c.  */
+#define OBSTACK_INTERFACE_VERSION 1
+
+/* Comment out all this code if we are using the GNU C Library, and are not
+   actually compiling the library itself, and the installed library
+   supports the same library interface we do.  This code is part of the GNU
+   C Library, but also included in many other GNU distributions.  Compiling
+   and linking in this code is a waste when using the GNU C library
+   (especially if it is a shared library).  Rather than having every GNU
+   program understand `configure --with-gnu-libc' and omit the object
+   files, it is simpler to just do this in the source for each such file.  */
+
+#include <stdio.h>		/* Random thing to get __GNU_LIBRARY__.  */
+#if !defined _LIBC && defined __GNU_LIBRARY__ && __GNU_LIBRARY__ > 1
+# include <gnu-versions.h>
+# if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION
+#  define ELIDE_CODE
+# endif
+#endif
+
+#include <stddef.h>
+
+#ifndef ELIDE_CODE
+
+# include <stdint.h>
+
+/* Determine default alignment.  */
+union fooround
+{
+  uintmax_t i;
+  long double d;
+  void *p;
+};
+struct fooalign
+{
+  char c;
+  union fooround u;
+};
+/* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
+   But in fact it might be less smart and round addresses to as much as
+   DEFAULT_ROUNDING.  So we prepare for it to do that.  */
+enum
+  {
+    DEFAULT_ALIGNMENT = offsetof (struct fooalign, u),
+    DEFAULT_ROUNDING = sizeof (union fooround)
+  };
+
+/* When we copy a long block of data, this is the unit to do it with.
+   On some machines, copying successive ints does not work;
+   in such a case, redefine COPYING_UNIT to `long' (if that works)
+   or `char' as a last resort.  */
+# ifndef COPYING_UNIT
+#  define COPYING_UNIT int
+# endif
+
+
+/* The functions allocating more room by calling `obstack_chunk_alloc'
+   jump to the handler pointed to by `obstack_alloc_failed_handler'.
+   This can be set to a user defined function which should either
+   abort gracefully or use longjump - but shouldn't return.  This
+   variable by default points to the internal function
+   `print_and_abort'.  */
+static void print_and_abort (void);
+void (*obstack_alloc_failed_handler) (void) = print_and_abort;
+
+/* Exit value used when `print_and_abort' is used.  */
+# include <stdlib.h>
+# ifdef _LIBC
+int obstack_exit_failure = EXIT_FAILURE;
+# else
+#  include "exitfail.h"
+#  define obstack_exit_failure exit_failure
+# endif
+
+# ifdef _LIBC
+#  if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
+/* A looong time ago (before 1994, anyway; we're not sure) this global variable
+   was used by non-GNU-C macros to avoid multiple evaluation.  The GNU C
+   library still exports it because somebody might use it.  */
+struct obstack *_obstack_compat;
+compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0);
+#  endif
+# endif
+
+/* Define a macro that either calls functions with the traditional malloc/free
+   calling interface, or calls functions with the mmalloc/mfree interface
+   (that adds an extra first argument), based on the state of use_extra_arg.
+   For free, do not use ?:, since some compilers, like the MIPS compilers,
+   do not allow (expr) ? void : void.  */
+
+# define CALL_CHUNKFUN(h, size) \
+  (((h) -> use_extra_arg) \
+   ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
+   : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
+
+# define CALL_FREEFUN(h, old_chunk) \
+  do { \
+    if ((h) -> use_extra_arg) \
+      (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
+    else \
+      (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
+  } while (0)
+
+
+/* Initialize an obstack H for use.  Specify chunk size SIZE (0 means default).
+   Objects start on multiples of ALIGNMENT (0 means use default).
+   CHUNKFUN is the function to use to allocate chunks,
+   and FREEFUN the function to free them.
+
+   Return nonzero if successful, calls obstack_alloc_failed_handler if
+   allocation fails.  */
+
+int
+_obstack_begin (struct obstack *h,
+		int size, int alignment,
+		void *(*chunkfun) (long),
+		void (*freefun) (void *))
+{
+  register struct _obstack_chunk *chunk; /* points to new chunk */
+
+  if (alignment == 0)
+    alignment = DEFAULT_ALIGNMENT;
+  if (size == 0)
+    /* Default size is what GNU malloc can fit in a 4096-byte block.  */
+    {
+      /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
+	 Use the values for range checking, because if range checking is off,
+	 the extra bytes won't be missed terribly, but if range checking is on
+	 and we used a larger request, a whole extra 4096 bytes would be
+	 allocated.
+
+	 These number are irrelevant to the new GNU malloc.  I suspect it is
+	 less sensitive to the size of the request.  */
+      int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
+		    + 4 + DEFAULT_ROUNDING - 1)
+		   & ~(DEFAULT_ROUNDING - 1));
+      size = 4096 - extra;
+    }
+
+  h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
+  h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
+  h->chunk_size = size;
+  h->alignment_mask = alignment - 1;
+  h->use_extra_arg = 0;
+
+  chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
+  if (!chunk)
+    (*obstack_alloc_failed_handler) ();
+  h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
+					       alignment - 1);
+  h->chunk_limit = chunk->limit
+    = (char *) chunk + h->chunk_size;
+  chunk->prev = 0;
+  /* The initial chunk now contains no empty object.  */
+  h->maybe_empty_object = 0;
+  h->alloc_failed = 0;
+  return 1;
+}
+
+int
+_obstack_begin_1 (struct obstack *h, int size, int alignment,
+		  void *(*chunkfun) (void *, long),
+		  void (*freefun) (void *, void *),
+		  void *arg)
+{
+  register struct _obstack_chunk *chunk; /* points to new chunk */
+
+  if (alignment == 0)
+    alignment = DEFAULT_ALIGNMENT;
+  if (size == 0)
+    /* Default size is what GNU malloc can fit in a 4096-byte block.  */
+    {
+      /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
+	 Use the values for range checking, because if range checking is off,
+	 the extra bytes won't be missed terribly, but if range checking is on
+	 and we used a larger request, a whole extra 4096 bytes would be
+	 allocated.
+
+	 These number are irrelevant to the new GNU malloc.  I suspect it is
+	 less sensitive to the size of the request.  */
+      int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
+		    + 4 + DEFAULT_ROUNDING - 1)
+		   & ~(DEFAULT_ROUNDING - 1));
+      size = 4096 - extra;
+    }
+
+  h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
+  h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
+  h->chunk_size = size;
+  h->alignment_mask = alignment - 1;
+  h->extra_arg = arg;
+  h->use_extra_arg = 1;
+
+  chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
+  if (!chunk)
+    (*obstack_alloc_failed_handler) ();
+  h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
+					       alignment - 1);
+  h->chunk_limit = chunk->limit
+    = (char *) chunk + h->chunk_size;
+  chunk->prev = 0;
+  /* The initial chunk now contains no empty object.  */
+  h->maybe_empty_object = 0;
+  h->alloc_failed = 0;
+  return 1;
+}
+
+/* Allocate a new current chunk for the obstack *H
+   on the assumption that LENGTH bytes need to be added
+   to the current object, or a new object of length LENGTH allocated.
+   Copies any partial object from the end of the old chunk
+   to the beginning of the new one.  */
+
+void
+_obstack_newchunk (struct obstack *h, int length)
+{
+  register struct _obstack_chunk *old_chunk = h->chunk;
+  register struct _obstack_chunk *new_chunk;
+  register long	new_size;
+  register long obj_size = h->next_free - h->object_base;
+  register long i;
+  long already;
+  char *object_base;
+
+  /* Compute size for new chunk.  */
+  new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100;
+  if (new_size < h->chunk_size)
+    new_size = h->chunk_size;
+
+  /* Allocate and initialize the new chunk.  */
+  new_chunk = CALL_CHUNKFUN (h, new_size);
+  if (!new_chunk)
+    (*obstack_alloc_failed_handler) ();
+  h->chunk = new_chunk;
+  new_chunk->prev = old_chunk;
+  new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
+
+  /* Compute an aligned object_base in the new chunk */
+  object_base =
+    __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask);
+
+  /* Move the existing object to the new chunk.
+     Word at a time is fast and is safe if the object
+     is sufficiently aligned.  */
+  if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
+    {
+      for (i = obj_size / sizeof (COPYING_UNIT) - 1;
+	   i >= 0; i--)
+	((COPYING_UNIT *)object_base)[i]
+	  = ((COPYING_UNIT *)h->object_base)[i];
+      /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
+	 but that can cross a page boundary on a machine
+	 which does not do strict alignment for COPYING_UNITS.  */
+      already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
+    }
+  else
+    already = 0;
+  /* Copy remaining bytes one by one.  */
+  for (i = already; i < obj_size; i++)
+    object_base[i] = h->object_base[i];
+
+  /* If the object just copied was the only data in OLD_CHUNK,
+     free that chunk and remove it from the chain.
+     But not if that chunk might contain an empty object.  */
+  if (! h->maybe_empty_object
+      && (h->object_base
+	  == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents,
+			  h->alignment_mask)))
+    {
+      new_chunk->prev = old_chunk->prev;
+      CALL_FREEFUN (h, old_chunk);
+    }
+
+  h->object_base = object_base;
+  h->next_free = h->object_base + obj_size;
+  /* The new chunk certainly contains no empty object yet.  */
+  h->maybe_empty_object = 0;
+}
+# ifdef _LIBC
+libc_hidden_def (_obstack_newchunk)
+# endif
+
+/* Return nonzero if object OBJ has been allocated from obstack H.
+   This is here for debugging.
+   If you use it in a program, you are probably losing.  */
+
+/* Suppress -Wmissing-prototypes warning.  We don't want to declare this in
+   obstack.h because it is just for debugging.  */
+int _obstack_allocated_p (struct obstack *h, void *obj);
+
+int
+_obstack_allocated_p (struct obstack *h, void *obj)
+{
+  register struct _obstack_chunk *lp;	/* below addr of any objects in this chunk */
+  register struct _obstack_chunk *plp;	/* point to previous chunk if any */
+
+  lp = (h)->chunk;
+  /* We use >= rather than > since the object cannot be exactly at
+     the beginning of the chunk but might be an empty object exactly
+     at the end of an adjacent chunk.  */
+  while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
+    {
+      plp = lp->prev;
+      lp = plp;
+    }
+  return lp != 0;
+}
+
+/* Free objects in obstack H, including OBJ and everything allocate
+   more recently than OBJ.  If OBJ is zero, free everything in H.  */
+
+# undef obstack_free
+
+void
+__obstack_free (struct obstack *h, void *obj)
+{
+  register struct _obstack_chunk *lp;	/* below addr of any objects in this chunk */
+  register struct _obstack_chunk *plp;	/* point to previous chunk if any */
+
+  lp = h->chunk;
+  /* We use >= because there cannot be an object at the beginning of a chunk.
+     But there can be an empty object at that address
+     at the end of another chunk.  */
+  while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
+    {
+      plp = lp->prev;
+      CALL_FREEFUN (h, lp);
+      lp = plp;
+      /* If we switch chunks, we can't tell whether the new current
+	 chunk contains an empty object, so assume that it may.  */
+      h->maybe_empty_object = 1;
+    }
+  if (lp)
+    {
+      h->object_base = h->next_free = (char *) (obj);
+      h->chunk_limit = lp->limit;
+      h->chunk = lp;
+    }
+  else if (obj != 0)
+    /* obj is not in any of the chunks! */
+    abort ();
+}
+
+# ifdef _LIBC
+/* Older versions of libc used a function _obstack_free intended to be
+   called by non-GCC compilers.  */
+strong_alias (obstack_free, _obstack_free)
+# endif
+
+int
+_obstack_memory_used (struct obstack *h)
+{
+  register struct _obstack_chunk* lp;
+  register int nbytes = 0;
+
+  for (lp = h->chunk; lp != 0; lp = lp->prev)
+    {
+      nbytes += lp->limit - (char *) lp;
+    }
+  return nbytes;
+}
+
+/* Define the error handler.  */
+# ifdef _LIBC
+#  include <libintl.h>
+# else
+#  include "gettext.h"
+# endif
+# ifndef _
+#  define _(msgid) gettext (msgid)
+# endif
+
+# ifdef _LIBC
+#  include <libio/iolibio.h>
+# endif
+
+# ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+#  if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
+#   define __attribute__(Spec) /* empty */
+#  endif
+# endif
+
+static void
+__attribute__ ((noreturn))
+print_and_abort (void)
+{
+  /* Don't change any of these strings.  Yes, it would be possible to add
+     the newline to the string and use fputs or so.  But this must not
+     happen because the "memory exhausted" message appears in other places
+     like this and the translation should be reused instead of creating
+     a very similar string which requires a separate translation.  */
+# ifdef _LIBC
+  (void) __fxprintf (NULL, "%s\n", _("memory exhausted"));
+# else
+  fprintf (stderr, "%s\n", _("memory exhausted"));
+# endif
+  exit (obstack_exit_failure);
+}
+
+#endif	/* !ELIDE_CODE */
diff --git a/src/bin/m4/lib/obstack.h b/src/bin/m4/lib/obstack.h
new file mode 100644
index 0000000000..3315dfe617
--- /dev/null
+++ b/src/bin/m4/lib/obstack.h
@@ -0,0 +1,513 @@
+/* obstack.h - object stack macros
+   Copyright (C) 1988-1994,1996-1999,2003,2004,2005,2006
+	Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Summary:
+
+All the apparent functions defined here are macros. The idea
+is that you would use these pre-tested macros to solve a
+very specific set of problems, and they would run fast.
+Caution: no side-effects in arguments please!! They may be
+evaluated MANY times!!
+
+These macros operate a stack of objects.  Each object starts life
+small, and may grow to maturity.  (Consider building a word syllable
+by syllable.)  An object can move while it is growing.  Once it has
+been "finished" it never changes address again.  So the "top of the
+stack" is typically an immature growing object, while the rest of the
+stack is of mature, fixed size and fixed address objects.
+
+These routines grab large chunks of memory, using a function you
+supply, called `obstack_chunk_alloc'.  On occasion, they free chunks,
+by calling `obstack_chunk_free'.  You must define them and declare
+them before using any obstack macros.
+
+Each independent stack is represented by a `struct obstack'.
+Each of the obstack macros expects a pointer to such a structure
+as the first argument.
+
+One motivation for this package is the problem of growing char strings
+in symbol tables.  Unless you are "fascist pig with a read-only mind"
+--Gosper's immortal quote from HAKMEM item 154, out of context--you
+would not like to put any arbitrary upper limit on the length of your
+symbols.
+
+In practice this often means you will build many short symbols and a
+few long symbols.  At the time you are reading a symbol you don't know
+how long it is.  One traditional method is to read a symbol into a
+buffer, realloc()ating the buffer every time you try to read a symbol
+that is longer than the buffer.  This is beaut, but you still will
+want to copy the symbol from the buffer to a more permanent
+symbol-table entry say about half the time.
+
+With obstacks, you can work differently.  Use one obstack for all symbol
+names.  As you read a symbol, grow the name in the obstack gradually.
+When the name is complete, finalize it.  Then, if the symbol exists already,
+free the newly read name.
+
+The way we do this is to take a large chunk, allocating memory from
+low addresses.  When you want to build a symbol in the chunk you just
+add chars above the current "high water mark" in the chunk.  When you
+have finished adding chars, because you got to the end of the symbol,
+you know how long the chars are, and you can create a new object.
+Mostly the chars will not burst over the highest address of the chunk,
+because you would typically expect a chunk to be (say) 100 times as
+long as an average object.
+
+In case that isn't clear, when we have enough chars to make up
+the object, THEY ARE ALREADY CONTIGUOUS IN THE CHUNK (guaranteed)
+so we just point to it where it lies.  No moving of chars is
+needed and this is the second win: potentially long strings need
+never be explicitly shuffled. Once an object is formed, it does not
+change its address during its lifetime.
+
+When the chars burst over a chunk boundary, we allocate a larger
+chunk, and then copy the partly formed object from the end of the old
+chunk to the beginning of the new larger chunk.  We then carry on
+accreting characters to the end of the object as we normally would.
+
+A special macro is provided to add a single char at a time to a
+growing object.  This allows the use of register variables, which
+break the ordinary 'growth' macro.
+
+Summary:
+	We allocate large chunks.
+	We carve out one object at a time from the current chunk.
+	Once carved, an object never moves.
+	We are free to append data of any size to the currently
+	  growing object.
+	Exactly one object is growing in an obstack at any one time.
+	You can run one obstack per control block.
+	You may have as many control blocks as you dare.
+	Because of the way we do it, you can `unwind' an obstack
+	  back to a previous state. (You may remove objects much
+	  as you would with a stack.)
+*/
+
+
+/* Don't do the contents of this file more than once.  */
+
+#ifndef _OBSTACK_H
+#define _OBSTACK_H 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* We need the type of a pointer subtraction.  If __PTRDIFF_TYPE__ is
+   defined, as with GNU C, use that; that way we don't pollute the
+   namespace with <stddef.h>'s symbols.  Otherwise, include <stddef.h>
+   and use ptrdiff_t.  */
+
+#ifdef __PTRDIFF_TYPE__
+# define PTR_INT_TYPE __PTRDIFF_TYPE__
+#else
+# include <stddef.h>
+# define PTR_INT_TYPE ptrdiff_t
+#endif
+
+/* If B is the base of an object addressed by P, return the result of
+   aligning P to the next multiple of A + 1.  B and P must be of type
+   char *.  A + 1 must be a power of 2.  */
+
+#define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A)))
+
+/* Similiar to _BPTR_ALIGN (B, P, A), except optimize the common case
+   where pointers can be converted to integers, aligned as integers,
+   and converted back again.  If PTR_INT_TYPE is narrower than a
+   pointer (e.g., the AS/400), play it safe and compute the alignment
+   relative to B.  Otherwise, use the faster strategy of computing the
+   alignment relative to 0.  */
+
+#define __PTR_ALIGN(B, P, A)						    \
+  __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void *) ? (B) : (char *) 0, \
+		P, A)
+
+#include <string.h>
+
+struct _obstack_chunk		/* Lives at front of each chunk. */
+{
+  char  *limit;			/* 1 past end of this chunk */
+  struct _obstack_chunk *prev;	/* address of prior chunk or NULL */
+  char	contents[4];		/* objects begin here */
+};
+
+struct obstack		/* control current object in current chunk */
+{
+  long	chunk_size;		/* preferred size to allocate chunks in */
+  struct _obstack_chunk *chunk;	/* address of current struct obstack_chunk */
+  char	*object_base;		/* address of object we are building */
+  char	*next_free;		/* where to add next char to current object */
+  char	*chunk_limit;		/* address of char after current chunk */
+  union
+  {
+    PTR_INT_TYPE tempint;
+    void *tempptr;
+  } temp;			/* Temporary for some macros.  */
+  int   alignment_mask;		/* Mask of alignment for each object. */
+  /* These prototypes vary based on `use_extra_arg', and we use
+     casts to the prototypeless function type in all assignments,
+     but having prototypes here quiets -Wstrict-prototypes.  */
+  struct _obstack_chunk *(*chunkfun) (void *, long);
+  void (*freefun) (void *, struct _obstack_chunk *);
+  void *extra_arg;		/* first arg for chunk alloc/dealloc funcs */
+  unsigned use_extra_arg:1;	/* chunk alloc/dealloc funcs take extra arg */
+  unsigned maybe_empty_object:1;/* There is a possibility that the current
+				   chunk contains a zero-length object.  This
+				   prevents freeing the chunk if we allocate
+				   a bigger chunk to replace it. */
+  unsigned alloc_failed:1;	/* No longer used, as we now call the failed
+				   handler on error, but retained for binary
+				   compatibility.  */
+};
+
+/* Declare the external functions we use; they are in obstack.c.  */
+
+extern void _obstack_newchunk (struct obstack *, int);
+extern int _obstack_begin (struct obstack *, int, int,
+			    void *(*) (long), void (*) (void *));
+extern int _obstack_begin_1 (struct obstack *, int, int,
+			     void *(*) (void *, long),
+			     void (*) (void *, void *), void *);
+extern int _obstack_memory_used (struct obstack *);
+
+/* The default name of the function for freeing a chunk is 'obstack_free',
+   but gnulib users can override this by defining '__obstack_free'.  */
+#ifndef __obstack_free
+# define __obstack_free obstack_free
+#endif
+extern void __obstack_free (struct obstack *obstack, void *block);
+
+
+/* Error handler called when `obstack_chunk_alloc' failed to allocate
+   more memory.  This can be set to a user defined function which
+   should either abort gracefully or use longjump - but shouldn't
+   return.  The default action is to print a message and abort.  */
+extern void (*obstack_alloc_failed_handler) (void);
+
+/* Exit value used when `print_and_abort' is used.  */
+extern int obstack_exit_failure;
+
+/* Pointer to beginning of object being allocated or to be allocated next.
+   Note that this might not be the final address of the object
+   because a new chunk might be needed to hold the final size.  */
+
+#define obstack_base(h) ((void *) (h)->object_base)
+
+/* Size for allocating ordinary chunks.  */
+
+#define obstack_chunk_size(h) ((h)->chunk_size)
+
+/* Pointer to next byte not yet allocated in current chunk.  */
+
+#define obstack_next_free(h)	((h)->next_free)
+
+/* Mask specifying low bits that should be clear in address of an object.  */
+
+#define obstack_alignment_mask(h) ((h)->alignment_mask)
+
+/* To prevent prototype warnings provide complete argument list.  */
+#define obstack_init(h)						\
+  _obstack_begin ((h), 0, 0,					\
+		  (void *(*) (long)) obstack_chunk_alloc,	\
+		  (void (*) (void *)) obstack_chunk_free)
+
+#define obstack_begin(h, size)					\
+  _obstack_begin ((h), (size), 0,				\
+		  (void *(*) (long)) obstack_chunk_alloc,	\
+		  (void (*) (void *)) obstack_chunk_free)
+
+#define obstack_specify_allocation(h, size, alignment, chunkfun, freefun)  \
+  _obstack_begin ((h), (size), (alignment),				   \
+		  (void *(*) (long)) (chunkfun),			   \
+		  (void (*) (void *)) (freefun))
+
+#define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, freefun, arg) \
+  _obstack_begin_1 ((h), (size), (alignment),				\
+		    (void *(*) (void *, long)) (chunkfun),		\
+		    (void (*) (void *, void *)) (freefun), (arg))
+
+#define obstack_chunkfun(h, newchunkfun) \
+  ((h) -> chunkfun = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun))
+
+#define obstack_freefun(h, newfreefun) \
+  ((h) -> freefun = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
+
+#define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar))
+
+#define obstack_blank_fast(h,n) ((h)->next_free += (n))
+
+#define obstack_memory_used(h) _obstack_memory_used (h)
+
+#if defined __GNUC__ && defined __STDC__ && __STDC__
+/* NextStep 2.0 cc is really gcc 1.93 but it defines __GNUC__ = 2 and
+   does not implement __extension__.  But that compiler doesn't define
+   __GNUC_MINOR__.  */
+# if __GNUC__ < 2 || (__NeXT__ && !__GNUC_MINOR__)
+#  define __extension__
+# endif
+
+/* For GNU C, if not -traditional,
+   we can define these macros to compute all args only once
+   without using a global variable.
+   Also, we can avoid using the `temp' slot, to make faster code.  */
+
+# define obstack_object_size(OBSTACK)					\
+  __extension__								\
+  ({ struct obstack const *__o = (OBSTACK);				\
+     (unsigned) (__o->next_free - __o->object_base); })
+
+# define obstack_room(OBSTACK)						\
+  __extension__								\
+  ({ struct obstack const *__o = (OBSTACK);				\
+     (unsigned) (__o->chunk_limit - __o->next_free); })
+
+# define obstack_make_room(OBSTACK,length)				\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   int __len = (length);						\
+   if (__o->chunk_limit - __o->next_free < __len)			\
+     _obstack_newchunk (__o, __len);					\
+   (void) 0; })
+
+# define obstack_empty_p(OBSTACK)					\
+  __extension__								\
+  ({ struct obstack const *__o = (OBSTACK);				\
+     (__o->chunk->prev == 0						\
+      && __o->next_free == __PTR_ALIGN ((char *) __o->chunk,		\
+					__o->chunk->contents,		\
+					__o->alignment_mask)); })
+
+# define obstack_grow(OBSTACK,where,length)				\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   int __len = (length);						\
+   if (__o->next_free + __len > __o->chunk_limit)			\
+     _obstack_newchunk (__o, __len);					\
+   memcpy (__o->next_free, where, __len);				\
+   __o->next_free += __len;						\
+   (void) 0; })
+
+# define obstack_grow0(OBSTACK,where,length)				\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   int __len = (length);						\
+   if (__o->next_free + __len + 1 > __o->chunk_limit)			\
+     _obstack_newchunk (__o, __len + 1);				\
+   memcpy (__o->next_free, where, __len);				\
+   __o->next_free += __len;						\
+   *(__o->next_free)++ = 0;						\
+   (void) 0; })
+
+# define obstack_1grow(OBSTACK,datum)					\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   if (__o->next_free + 1 > __o->chunk_limit)				\
+     _obstack_newchunk (__o, 1);					\
+   obstack_1grow_fast (__o, datum);					\
+   (void) 0; })
+
+/* These assume that the obstack alignment is good enough for pointers
+   or ints, and that the data added so far to the current object
+   shares that much alignment.  */
+
+# define obstack_ptr_grow(OBSTACK,datum)				\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   if (__o->next_free + sizeof (void *) > __o->chunk_limit)		\
+     _obstack_newchunk (__o, sizeof (void *));				\
+   obstack_ptr_grow_fast (__o, datum); })				\
+
+# define obstack_int_grow(OBSTACK,datum)				\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   if (__o->next_free + sizeof (int) > __o->chunk_limit)		\
+     _obstack_newchunk (__o, sizeof (int));				\
+   obstack_int_grow_fast (__o, datum); })
+
+# define obstack_ptr_grow_fast(OBSTACK,aptr)				\
+__extension__								\
+({ struct obstack *__o1 = (OBSTACK);					\
+   *(const void **) __o1->next_free = (aptr);				\
+   __o1->next_free += sizeof (const void *);				\
+   (void) 0; })
+
+# define obstack_int_grow_fast(OBSTACK,aint)				\
+__extension__								\
+({ struct obstack *__o1 = (OBSTACK);					\
+   *(int *) __o1->next_free = (aint);					\
+   __o1->next_free += sizeof (int);					\
+   (void) 0; })
+
+# define obstack_blank(OBSTACK,length)					\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   int __len = (length);						\
+   if (__o->chunk_limit - __o->next_free < __len)			\
+     _obstack_newchunk (__o, __len);					\
+   obstack_blank_fast (__o, __len);					\
+   (void) 0; })
+
+# define obstack_alloc(OBSTACK,length)					\
+__extension__								\
+({ struct obstack *__h = (OBSTACK);					\
+   obstack_blank (__h, (length));					\
+   obstack_finish (__h); })
+
+# define obstack_copy(OBSTACK,where,length)				\
+__extension__								\
+({ struct obstack *__h = (OBSTACK);					\
+   obstack_grow (__h, (where), (length));				\
+   obstack_finish (__h); })
+
+# define obstack_copy0(OBSTACK,where,length)				\
+__extension__								\
+({ struct obstack *__h = (OBSTACK);					\
+   obstack_grow0 (__h, (where), (length));				\
+   obstack_finish (__h); })
+
+/* The local variable is named __o1 to avoid a name conflict
+   when obstack_blank is called.  */
+# define obstack_finish(OBSTACK)					\
+__extension__								\
+({ struct obstack *__o1 = (OBSTACK);					\
+   void *__value = (void *) __o1->object_base;				\
+   if (__o1->next_free == __value)					\
+     __o1->maybe_empty_object = 1;					\
+   __o1->next_free							\
+     = __PTR_ALIGN (__o1->object_base, __o1->next_free,			\
+		    __o1->alignment_mask);				\
+   if (__o1->next_free - (char *)__o1->chunk				\
+       > __o1->chunk_limit - (char *)__o1->chunk)			\
+     __o1->next_free = __o1->chunk_limit;				\
+   __o1->object_base = __o1->next_free;					\
+   __value; })
+
+# define obstack_free(OBSTACK, OBJ)					\
+__extension__								\
+({ struct obstack *__o = (OBSTACK);					\
+   void *__obj = (OBJ);							\
+   if (__obj > (void *)__o->chunk && __obj < (void *)__o->chunk_limit)  \
+     __o->next_free = __o->object_base = (char *)__obj;			\
+   else (__obstack_free) (__o, __obj); })
+
+#else /* not __GNUC__ or not __STDC__ */
+
+# define obstack_object_size(h) \
+ (unsigned) ((h)->next_free - (h)->object_base)
+
+# define obstack_room(h)		\
+ (unsigned) ((h)->chunk_limit - (h)->next_free)
+
+# define obstack_empty_p(h) \
+ ((h)->chunk->prev == 0							\
+  && (h)->next_free == __PTR_ALIGN ((char *) (h)->chunk,		\
+				    (h)->chunk->contents,		\
+				    (h)->alignment_mask))
+
+/* Note that the call to _obstack_newchunk is enclosed in (..., 0)
+   so that we can avoid having void expressions
+   in the arms of the conditional expression.
+   Casting the third operand to void was tried before,
+   but some compilers won't accept it.  */
+
+# define obstack_make_room(h,length)					\
+( (h)->temp.tempint = (length),						\
+  (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit)		\
+   ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0))
+
+# define obstack_grow(h,where,length)					\
+( (h)->temp.tempint = (length),						\
+  (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit)		\
+   ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0),		\
+  memcpy ((h)->next_free, where, (h)->temp.tempint),			\
+  (h)->next_free += (h)->temp.tempint)
+
+# define obstack_grow0(h,where,length)					\
+( (h)->temp.tempint = (length),						\
+  (((h)->next_free + (h)->temp.tempint + 1 > (h)->chunk_limit)		\
+   ? (_obstack_newchunk ((h), (h)->temp.tempint + 1), 0) : 0),		\
+  memcpy ((h)->next_free, where, (h)->temp.tempint),			\
+  (h)->next_free += (h)->temp.tempint,					\
+  *((h)->next_free)++ = 0)
+
+# define obstack_1grow(h,datum)						\
+( (((h)->next_free + 1 > (h)->chunk_limit)				\
+   ? (_obstack_newchunk ((h), 1), 0) : 0),				\
+  obstack_1grow_fast (h, datum))
+
+# define obstack_ptr_grow(h,datum)					\
+( (((h)->next_free + sizeof (char *) > (h)->chunk_limit)		\
+   ? (_obstack_newchunk ((h), sizeof (char *)), 0) : 0),		\
+  obstack_ptr_grow_fast (h, datum))
+
+# define obstack_int_grow(h,datum)					\
+( (((h)->next_free + sizeof (int) > (h)->chunk_limit)			\
+   ? (_obstack_newchunk ((h), sizeof (int)), 0) : 0),			\
+  obstack_int_grow_fast (h, datum))
+
+# define obstack_ptr_grow_fast(h,aptr)					\
+  (((const void **) ((h)->next_free += sizeof (void *)))[-1] = (aptr))
+
+# define obstack_int_grow_fast(h,aint)					\
+  (((int *) ((h)->next_free += sizeof (int)))[-1] = (aint))
+
+# define obstack_blank(h,length)					\
+( (h)->temp.tempint = (length),						\
+  (((h)->chunk_limit - (h)->next_free < (h)->temp.tempint)		\
+   ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0),		\
+  obstack_blank_fast (h, (h)->temp.tempint))
+
+# define obstack_alloc(h,length)					\
+ (obstack_blank ((h), (length)), obstack_finish ((h)))
+
+# define obstack_copy(h,where,length)					\
+ (obstack_grow ((h), (where), (length)), obstack_finish ((h)))
+
+# define obstack_copy0(h,where,length)					\
+ (obstack_grow0 ((h), (where), (length)), obstack_finish ((h)))
+
+# define obstack_finish(h)						\
+( ((h)->next_free == (h)->object_base					\
+   ? (((h)->maybe_empty_object = 1), 0)					\
+   : 0),								\
+  (h)->temp.tempptr = (h)->object_base,					\
+  (h)->next_free							\
+    = __PTR_ALIGN ((h)->object_base, (h)->next_free,			\
+		   (h)->alignment_mask),				\
+  (((h)->next_free - (char *) (h)->chunk				\
+    > (h)->chunk_limit - (char *) (h)->chunk)				\
+   ? ((h)->next_free = (h)->chunk_limit) : 0),				\
+  (h)->object_base = (h)->next_free,					\
+  (h)->temp.tempptr)
+
+# define obstack_free(h,obj)						\
+( (h)->temp.tempint = (char *) (obj) - (char *) (h)->chunk,		\
+  ((((h)->temp.tempint > 0						\
+    && (h)->temp.tempint < (h)->chunk_limit - (char *) (h)->chunk))	\
+   ? (int) ((h)->next_free = (h)->object_base				\
+	    = (h)->temp.tempint + (char *) (h)->chunk)			\
+   : (((__obstack_free) ((h), (h)->temp.tempint + (char *) (h)->chunk), 0), 0)))
+
+#endif /* not __GNUC__ or not __STDC__ */
+
+#ifdef __cplusplus
+}	/* C++ */
+#endif
+
+#endif /* obstack.h */
diff --git a/src/bin/m4/lib/pathmax.h b/src/bin/m4/lib/pathmax.h
new file mode 100644
index 0000000000..6941e457e3
--- /dev/null
+++ b/src/bin/m4/lib/pathmax.h
@@ -0,0 +1,47 @@
+/* Define PATH_MAX somehow.  Requires sys/types.h.
+   Copyright (C) 1992, 1999, 2001, 2003, 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _PATHMAX_H
+# define _PATHMAX_H
+
+# include <unistd.h>
+
+# include <limits.h>
+
+# ifndef _POSIX_PATH_MAX
+#  define _POSIX_PATH_MAX 256
+# endif
+
+# if !defined PATH_MAX && defined _PC_PATH_MAX
+#  define PATH_MAX (pathconf ("/", _PC_PATH_MAX) < 1 ? 1024 \
+		    : pathconf ("/", _PC_PATH_MAX))
+# endif
+
+/* Don't include sys/param.h if it already has been.  */
+# if defined HAVE_SYS_PARAM_H && !defined PATH_MAX && !defined MAXPATHLEN
+#  include <sys/param.h>
+# endif
+
+# if !defined PATH_MAX && defined MAXPATHLEN
+#  define PATH_MAX MAXPATHLEN
+# endif
+
+# ifndef PATH_MAX
+#  define PATH_MAX _POSIX_PATH_MAX
+# endif
+
+#endif /* _PATHMAX_H */
diff --git a/src/bin/m4/lib/pipe-safer.c b/src/bin/m4/lib/pipe-safer.c
new file mode 100644
index 0000000000..e4431b33a4
--- /dev/null
+++ b/src/bin/m4/lib/pipe-safer.c
@@ -0,0 +1,57 @@
+/* Invoke pipe, but avoid some glitches.
+   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Jim Meyering.  */
+
+#include <config.h>
+
+#include "unistd-safer.h"
+
+#include <unistd.h>
+#include <errno.h>
+
+/* Like pipe, but ensure that neither of the file descriptors is
+   STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO.  Fail with ENOSYS on
+   platforms that lack pipe.  */
+
+int
+pipe_safer (int fd[2])
+{
+#if HAVE_PIPE
+  if (pipe (fd) == 0)
+    {
+      int i;
+      for (i = 0; i < 2; i++)
+	{
+	  fd[i] = fd_safer (fd[i]);
+	  if (fd[i] < 0)
+	    {
+	      int e = errno;
+	      close (fd[1 - i]);
+	      errno = e;
+	      return -1;
+	    }
+	}
+
+      return 0;
+    }
+#else
+  errno = ENOSYS;
+#endif
+
+  return -1;
+}
diff --git a/src/bin/m4/lib/printf-args.c b/src/bin/m4/lib/printf-args.c
new file mode 100644
index 0000000000..358801c97b
--- /dev/null
+++ b/src/bin/m4/lib/printf-args.c
@@ -0,0 +1,141 @@
+/* Decomposed printf argument list.
+   Copyright (C) 1999, 2002-2003, 2005-2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "printf-args.h"
+
+#ifdef STATIC
+STATIC
+#endif
+int
+printf_fetchargs (va_list args, arguments *a)
+{
+  size_t i;
+  argument *ap;
+
+  for (i = 0, ap = &a->arg[0]; i < a->count; i++, ap++)
+    switch (ap->type)
+      {
+      case TYPE_SCHAR:
+	ap->a.a_schar = va_arg (args, /*signed char*/ int);
+	break;
+      case TYPE_UCHAR:
+	ap->a.a_uchar = va_arg (args, /*unsigned char*/ int);
+	break;
+      case TYPE_SHORT:
+	ap->a.a_short = va_arg (args, /*short*/ int);
+	break;
+      case TYPE_USHORT:
+	ap->a.a_ushort = va_arg (args, /*unsigned short*/ int);
+	break;
+      case TYPE_INT:
+	ap->a.a_int = va_arg (args, int);
+	break;
+      case TYPE_UINT:
+	ap->a.a_uint = va_arg (args, unsigned int);
+	break;
+      case TYPE_LONGINT:
+	ap->a.a_longint = va_arg (args, long int);
+	break;
+      case TYPE_ULONGINT:
+	ap->a.a_ulongint = va_arg (args, unsigned long int);
+	break;
+#ifdef HAVE_LONG_LONG_INT
+      case TYPE_LONGLONGINT:
+	ap->a.a_longlongint = va_arg (args, long long int);
+	break;
+      case TYPE_ULONGLONGINT:
+	ap->a.a_ulonglongint = va_arg (args, unsigned long long int);
+	break;
+#endif
+      case TYPE_DOUBLE:
+	ap->a.a_double = va_arg (args, double);
+	break;
+#ifdef HAVE_LONG_DOUBLE
+      case TYPE_LONGDOUBLE:
+	ap->a.a_longdouble = va_arg (args, long double);
+	break;
+#endif
+      case TYPE_CHAR:
+	ap->a.a_char = va_arg (args, int);
+	break;
+#ifdef HAVE_WINT_T
+      case TYPE_WIDE_CHAR:
+	/* Although ISO C 99 7.24.1.(2) says that wint_t is "unchanged by
+	   default argument promotions", this is not the case in mingw32,
+	   where wint_t is 'unsigned short'.  */
+	ap->a.a_wide_char =
+	  (sizeof (wint_t) < sizeof (int)
+	   ? va_arg (args, int)
+	   : va_arg (args, wint_t));
+	break;
+#endif
+      case TYPE_STRING:
+	ap->a.a_string = va_arg (args, const char *);
+	/* A null pointer is an invalid argument for "%s", but in practice
+	   it occurs quite frequently in printf statements that produce
+	   debug output.  Use a fallback in this case.  */
+	if (ap->a.a_string == NULL)
+	  ap->a.a_string = "(NULL)";
+	break;
+#ifdef HAVE_WCHAR_T
+      case TYPE_WIDE_STRING:
+	ap->a.a_wide_string = va_arg (args, const wchar_t *);
+	/* A null pointer is an invalid argument for "%ls", but in practice
+	   it occurs quite frequently in printf statements that produce
+	   debug output.  Use a fallback in this case.  */
+	if (ap->a.a_wide_string == NULL)
+	  {
+	    static const wchar_t wide_null_string[] =
+	      {
+		(wchar_t)'(',
+		(wchar_t)'N', (wchar_t)'U', (wchar_t)'L', (wchar_t)'L',
+		(wchar_t)')',
+		(wchar_t)0
+	      };
+	    ap->a.a_wide_string = wide_null_string;
+	  }
+	break;
+#endif
+      case TYPE_POINTER:
+	ap->a.a_pointer = va_arg (args, void *);
+	break;
+      case TYPE_COUNT_SCHAR_POINTER:
+	ap->a.a_count_schar_pointer = va_arg (args, signed char *);
+	break;
+      case TYPE_COUNT_SHORT_POINTER:
+	ap->a.a_count_short_pointer = va_arg (args, short *);
+	break;
+      case TYPE_COUNT_INT_POINTER:
+	ap->a.a_count_int_pointer = va_arg (args, int *);
+	break;
+      case TYPE_COUNT_LONGINT_POINTER:
+	ap->a.a_count_longint_pointer = va_arg (args, long int *);
+	break;
+#ifdef HAVE_LONG_LONG_INT
+      case TYPE_COUNT_LONGLONGINT_POINTER:
+	ap->a.a_count_longlongint_pointer = va_arg (args, long long int *);
+	break;
+#endif
+      default:
+	/* Unknown type.  */
+	return -1;
+      }
+  return 0;
+}
diff --git a/src/bin/m4/lib/printf-args.h b/src/bin/m4/lib/printf-args.h
new file mode 100644
index 0000000000..5759da0ee9
--- /dev/null
+++ b/src/bin/m4/lib/printf-args.h
@@ -0,0 +1,136 @@
+/* Decomposed printf argument list.
+   Copyright (C) 1999, 2002-2003, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _PRINTF_ARGS_H
+#define _PRINTF_ARGS_H
+
+/* Get size_t.  */
+#include <stddef.h>
+
+/* Get wchar_t.  */
+#ifdef HAVE_WCHAR_T
+# include <stddef.h>
+#endif
+
+/* Get wint_t.  */
+#ifdef HAVE_WINT_T
+# include <wchar.h>
+#endif
+
+/* Get va_list.  */
+#include <stdarg.h>
+
+
+/* Argument types */
+typedef enum
+{
+  TYPE_NONE,
+  TYPE_SCHAR,
+  TYPE_UCHAR,
+  TYPE_SHORT,
+  TYPE_USHORT,
+  TYPE_INT,
+  TYPE_UINT,
+  TYPE_LONGINT,
+  TYPE_ULONGINT,
+#ifdef HAVE_LONG_LONG_INT
+  TYPE_LONGLONGINT,
+  TYPE_ULONGLONGINT,
+#endif
+  TYPE_DOUBLE,
+#ifdef HAVE_LONG_DOUBLE
+  TYPE_LONGDOUBLE,
+#endif
+  TYPE_CHAR,
+#ifdef HAVE_WINT_T
+  TYPE_WIDE_CHAR,
+#endif
+  TYPE_STRING,
+#ifdef HAVE_WCHAR_T
+  TYPE_WIDE_STRING,
+#endif
+  TYPE_POINTER,
+  TYPE_COUNT_SCHAR_POINTER,
+  TYPE_COUNT_SHORT_POINTER,
+  TYPE_COUNT_INT_POINTER,
+  TYPE_COUNT_LONGINT_POINTER
+#ifdef HAVE_LONG_LONG_INT
+, TYPE_COUNT_LONGLONGINT_POINTER
+#endif
+} arg_type;
+
+/* Polymorphic argument */
+typedef struct
+{
+  arg_type type;
+  union
+  {
+    signed char			a_schar;
+    unsigned char		a_uchar;
+    short			a_short;
+    unsigned short		a_ushort;
+    int				a_int;
+    unsigned int		a_uint;
+    long int			a_longint;
+    unsigned long int		a_ulongint;
+#ifdef HAVE_LONG_LONG_INT
+    long long int		a_longlongint;
+    unsigned long long int	a_ulonglongint;
+#endif
+    float			a_float;
+    double			a_double;
+#ifdef HAVE_LONG_DOUBLE
+    long double			a_longdouble;
+#endif
+    int				a_char;
+#ifdef HAVE_WINT_T
+    wint_t			a_wide_char;
+#endif
+    const char*			a_string;
+#ifdef HAVE_WCHAR_T
+    const wchar_t*		a_wide_string;
+#endif
+    void*			a_pointer;
+    signed char *		a_count_schar_pointer;
+    short *			a_count_short_pointer;
+    int *			a_count_int_pointer;
+    long int *			a_count_longint_pointer;
+#ifdef HAVE_LONG_LONG_INT
+    long long int *		a_count_longlongint_pointer;
+#endif
+  }
+  a;
+}
+argument;
+
+typedef struct
+{
+  size_t count;
+  argument *arg;
+}
+arguments;
+
+
+/* Fetch the arguments, putting them into a. */
+#ifdef STATIC
+STATIC
+#else
+extern
+#endif
+int printf_fetchargs (va_list args, arguments *a);
+
+#endif /* _PRINTF_ARGS_H */
diff --git a/src/bin/m4/lib/printf-parse.c b/src/bin/m4/lib/printf-parse.c
new file mode 100644
index 0000000000..9a86f7738e
--- /dev/null
+++ b/src/bin/m4/lib/printf-parse.c
@@ -0,0 +1,543 @@
+/* Formatted output to strings.
+   Copyright (C) 1999-2000, 2002-2003, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#if WIDE_CHAR_VERSION
+# include "wprintf-parse.h"
+#else
+# include "printf-parse.h"
+#endif
+
+/* Get size_t, NULL.  */
+#include <stddef.h>
+
+/* Get intmax_t.  */
+#if HAVE_STDINT_H_WITH_UINTMAX
+# include <stdint.h>
+#endif
+#if HAVE_INTTYPES_H_WITH_UINTMAX
+# include <inttypes.h>
+#endif
+
+/* malloc(), realloc(), free().  */
+#include <stdlib.h>
+
+/* Checked size_t computations.  */
+#include "xsize.h"
+
+#if WIDE_CHAR_VERSION
+# define PRINTF_PARSE wprintf_parse
+# define CHAR_T wchar_t
+# define DIRECTIVE wchar_t_directive
+# define DIRECTIVES wchar_t_directives
+#else
+# define PRINTF_PARSE printf_parse
+# define CHAR_T char
+# define DIRECTIVE char_directive
+# define DIRECTIVES char_directives
+#endif
+
+#ifdef STATIC
+STATIC
+#endif
+int
+PRINTF_PARSE (const CHAR_T *format, DIRECTIVES *d, arguments *a)
+{
+  const CHAR_T *cp = format;		/* pointer into format */
+  size_t arg_posn = 0;		/* number of regular arguments consumed */
+  size_t d_allocated;			/* allocated elements of d->dir */
+  size_t a_allocated;			/* allocated elements of a->arg */
+  size_t max_width_length = 0;
+  size_t max_precision_length = 0;
+
+  d->count = 0;
+  d_allocated = 1;
+  d->dir = (DIRECTIVE *) malloc (d_allocated * sizeof (DIRECTIVE));
+  if (d->dir == NULL)
+    /* Out of memory.  */
+    return -1;
+
+  a->count = 0;
+  a_allocated = 0;
+  a->arg = NULL;
+
+#define REGISTER_ARG(_index_,_type_) \
+  {									\
+    size_t n = (_index_);						\
+    if (n >= a_allocated)						\
+      {									\
+	size_t memory_size;						\
+	argument *memory;						\
+									\
+	a_allocated = xtimes (a_allocated, 2);				\
+	if (a_allocated <= n)						\
+	  a_allocated = xsum (n, 1);					\
+	memory_size = xtimes (a_allocated, sizeof (argument));		\
+	if (size_overflow_p (memory_size))				\
+	  /* Overflow, would lead to out of memory.  */			\
+	  goto error;							\
+	memory = (argument *) (a->arg					\
+			       ? realloc (a->arg, memory_size)		\
+			       : malloc (memory_size));			\
+	if (memory == NULL)						\
+	  /* Out of memory.  */						\
+	  goto error;							\
+	a->arg = memory;						\
+      }									\
+    while (a->count <= n)						\
+      a->arg[a->count++].type = TYPE_NONE;				\
+    if (a->arg[n].type == TYPE_NONE)					\
+      a->arg[n].type = (_type_);					\
+    else if (a->arg[n].type != (_type_))				\
+      /* Ambiguous type for positional argument.  */			\
+      goto error;							\
+  }
+
+  while (*cp != '\0')
+    {
+      CHAR_T c = *cp++;
+      if (c == '%')
+	{
+	  size_t arg_index = ARG_NONE;
+	  DIRECTIVE *dp = &d->dir[d->count];/* pointer to next directive */
+
+	  /* Initialize the next directive.  */
+	  dp->dir_start = cp - 1;
+	  dp->flags = 0;
+	  dp->width_start = NULL;
+	  dp->width_end = NULL;
+	  dp->width_arg_index = ARG_NONE;
+	  dp->precision_start = NULL;
+	  dp->precision_end = NULL;
+	  dp->precision_arg_index = ARG_NONE;
+	  dp->arg_index = ARG_NONE;
+
+	  /* Test for positional argument.  */
+	  if (*cp >= '0' && *cp <= '9')
+	    {
+	      const CHAR_T *np;
+
+	      for (np = cp; *np >= '0' && *np <= '9'; np++)
+		;
+	      if (*np == '$')
+		{
+		  size_t n = 0;
+
+		  for (np = cp; *np >= '0' && *np <= '9'; np++)
+		    n = xsum (xtimes (n, 10), *np - '0');
+		  if (n == 0)
+		    /* Positional argument 0.  */
+		    goto error;
+		  if (size_overflow_p (n))
+		    /* n too large, would lead to out of memory later.  */
+		    goto error;
+		  arg_index = n - 1;
+		  cp = np + 1;
+		}
+	    }
+
+	  /* Read the flags.  */
+	  for (;;)
+	    {
+	      if (*cp == '\'')
+		{
+		  dp->flags |= FLAG_GROUP;
+		  cp++;
+		}
+	      else if (*cp == '-')
+		{
+		  dp->flags |= FLAG_LEFT;
+		  cp++;
+		}
+	      else if (*cp == '+')
+		{
+		  dp->flags |= FLAG_SHOWSIGN;
+		  cp++;
+		}
+	      else if (*cp == ' ')
+		{
+		  dp->flags |= FLAG_SPACE;
+		  cp++;
+		}
+	      else if (*cp == '#')
+		{
+		  dp->flags |= FLAG_ALT;
+		  cp++;
+		}
+	      else if (*cp == '0')
+		{
+		  dp->flags |= FLAG_ZERO;
+		  cp++;
+		}
+	      else
+		break;
+	    }
+
+	  /* Parse the field width.  */
+	  if (*cp == '*')
+	    {
+	      dp->width_start = cp;
+	      cp++;
+	      dp->width_end = cp;
+	      if (max_width_length < 1)
+		max_width_length = 1;
+
+	      /* Test for positional argument.  */
+	      if (*cp >= '0' && *cp <= '9')
+		{
+		  const CHAR_T *np;
+
+		  for (np = cp; *np >= '0' && *np <= '9'; np++)
+		    ;
+		  if (*np == '$')
+		    {
+		      size_t n = 0;
+
+		      for (np = cp; *np >= '0' && *np <= '9'; np++)
+			n = xsum (xtimes (n, 10), *np - '0');
+		      if (n == 0)
+			/* Positional argument 0.  */
+			goto error;
+		      if (size_overflow_p (n))
+			/* n too large, would lead to out of memory later.  */
+			goto error;
+		      dp->width_arg_index = n - 1;
+		      cp = np + 1;
+		    }
+		}
+	      if (dp->width_arg_index == ARG_NONE)
+		{
+		  dp->width_arg_index = arg_posn++;
+		  if (dp->width_arg_index == ARG_NONE)
+		    /* arg_posn wrapped around.  */
+		    goto error;
+		}
+	      REGISTER_ARG (dp->width_arg_index, TYPE_INT);
+	    }
+	  else if (*cp >= '0' && *cp <= '9')
+	    {
+	      size_t width_length;
+
+	      dp->width_start = cp;
+	      for (; *cp >= '0' && *cp <= '9'; cp++)
+		;
+	      dp->width_end = cp;
+	      width_length = dp->width_end - dp->width_start;
+	      if (max_width_length < width_length)
+		max_width_length = width_length;
+	    }
+
+	  /* Parse the precision.  */
+	  if (*cp == '.')
+	    {
+	      cp++;
+	      if (*cp == '*')
+		{
+		  dp->precision_start = cp - 1;
+		  cp++;
+		  dp->precision_end = cp;
+		  if (max_precision_length < 2)
+		    max_precision_length = 2;
+
+		  /* Test for positional argument.  */
+		  if (*cp >= '0' && *cp <= '9')
+		    {
+		      const CHAR_T *np;
+
+		      for (np = cp; *np >= '0' && *np <= '9'; np++)
+			;
+		      if (*np == '$')
+			{
+			  size_t n = 0;
+
+			  for (np = cp; *np >= '0' && *np <= '9'; np++)
+			    n = xsum (xtimes (n, 10), *np - '0');
+			  if (n == 0)
+			    /* Positional argument 0.  */
+			    goto error;
+			  if (size_overflow_p (n))
+			    /* n too large, would lead to out of memory
+			       later.  */
+			    goto error;
+			  dp->precision_arg_index = n - 1;
+			  cp = np + 1;
+			}
+		    }
+		  if (dp->precision_arg_index == ARG_NONE)
+		    {
+		      dp->precision_arg_index = arg_posn++;
+		      if (dp->precision_arg_index == ARG_NONE)
+			/* arg_posn wrapped around.  */
+			goto error;
+		    }
+		  REGISTER_ARG (dp->precision_arg_index, TYPE_INT);
+		}
+	      else
+		{
+		  size_t precision_length;
+
+		  dp->precision_start = cp - 1;
+		  for (; *cp >= '0' && *cp <= '9'; cp++)
+		    ;
+		  dp->precision_end = cp;
+		  precision_length = dp->precision_end - dp->precision_start;
+		  if (max_precision_length < precision_length)
+		    max_precision_length = precision_length;
+		}
+	    }
+
+	  {
+	    arg_type type;
+
+	    /* Parse argument type/size specifiers.  */
+	    {
+	      int flags = 0;
+
+	      for (;;)
+		{
+		  if (*cp == 'h')
+		    {
+		      flags |= (1 << (flags & 1));
+		      cp++;
+		    }
+		  else if (*cp == 'L')
+		    {
+		      flags |= 4;
+		      cp++;
+		    }
+		  else if (*cp == 'l')
+		    {
+		      flags += 8;
+		      cp++;
+		    }
+#ifdef HAVE_INTMAX_T
+		  else if (*cp == 'j')
+		    {
+		      if (sizeof (intmax_t) > sizeof (long))
+			{
+			  /* intmax_t = long long */
+			  flags += 16;
+			}
+		      else if (sizeof (intmax_t) > sizeof (int))
+			{
+			  /* intmax_t = long */
+			  flags += 8;
+			}
+		      cp++;
+		    }
+#endif
+		  else if (*cp == 'z' || *cp == 'Z')
+		    {
+		      /* 'z' is standardized in ISO C 99, but glibc uses 'Z'
+			 because the warning facility in gcc-2.95.2 understands
+			 only 'Z' (see gcc-2.95.2/gcc/c-common.c:1784).  */
+		      if (sizeof (size_t) > sizeof (long))
+			{
+			  /* size_t = long long */
+			  flags += 16;
+			}
+		      else if (sizeof (size_t) > sizeof (int))
+			{
+			  /* size_t = long */
+			  flags += 8;
+			}
+		      cp++;
+		    }
+		  else if (*cp == 't')
+		    {
+		      if (sizeof (ptrdiff_t) > sizeof (long))
+			{
+			  /* ptrdiff_t = long long */
+			  flags += 16;
+			}
+		      else if (sizeof (ptrdiff_t) > sizeof (int))
+			{
+			  /* ptrdiff_t = long */
+			  flags += 8;
+			}
+		      cp++;
+		    }
+		  else
+		    break;
+		}
+
+	      /* Read the conversion character.  */
+	      c = *cp++;
+	      switch (c)
+		{
+		case 'd': case 'i':
+#ifdef HAVE_LONG_LONG_INT
+		  /* If 'long long' exists and is larger than 'long':  */
+		  if (flags >= 16 || (flags & 4))
+		    type = TYPE_LONGLONGINT;
+		  else
+#endif
+		  /* If 'long long' exists and is the same as 'long', we parse
+		     "lld" into TYPE_LONGINT.  */
+		  if (flags >= 8)
+		    type = TYPE_LONGINT;
+		  else if (flags & 2)
+		    type = TYPE_SCHAR;
+		  else if (flags & 1)
+		    type = TYPE_SHORT;
+		  else
+		    type = TYPE_INT;
+		  break;
+		case 'o': case 'u': case 'x': case 'X':
+#ifdef HAVE_LONG_LONG_INT
+		  /* If 'long long' exists and is larger than 'long':  */
+		  if (flags >= 16 || (flags & 4))
+		    type = TYPE_ULONGLONGINT;
+		  else
+#endif
+		  /* If 'unsigned long long' exists and is the same as
+		     'unsigned long', we parse "llu" into TYPE_ULONGINT.  */
+		  if (flags >= 8)
+		    type = TYPE_ULONGINT;
+		  else if (flags & 2)
+		    type = TYPE_UCHAR;
+		  else if (flags & 1)
+		    type = TYPE_USHORT;
+		  else
+		    type = TYPE_UINT;
+		  break;
+		case 'f': case 'F': case 'e': case 'E': case 'g': case 'G':
+		case 'a': case 'A':
+#ifdef HAVE_LONG_DOUBLE
+		  if (flags >= 16 || (flags & 4))
+		    type = TYPE_LONGDOUBLE;
+		  else
+#endif
+		  type = TYPE_DOUBLE;
+		  break;
+		case 'c':
+		  if (flags >= 8)
+#ifdef HAVE_WINT_T
+		    type = TYPE_WIDE_CHAR;
+#else
+		    goto error;
+#endif
+		  else
+		    type = TYPE_CHAR;
+		  break;
+#ifdef HAVE_WINT_T
+		case 'C':
+		  type = TYPE_WIDE_CHAR;
+		  c = 'c';
+		  break;
+#endif
+		case 's':
+		  if (flags >= 8)
+#ifdef HAVE_WCHAR_T
+		    type = TYPE_WIDE_STRING;
+#else
+		    goto error;
+#endif
+		  else
+		    type = TYPE_STRING;
+		  break;
+#ifdef HAVE_WCHAR_T
+		case 'S':
+		  type = TYPE_WIDE_STRING;
+		  c = 's';
+		  break;
+#endif
+		case 'p':
+		  type = TYPE_POINTER;
+		  break;
+		case 'n':
+#ifdef HAVE_LONG_LONG_INT
+		  /* If 'long long' exists and is larger than 'long':  */
+		  if (flags >= 16 || (flags & 4))
+		    type = TYPE_COUNT_LONGLONGINT_POINTER;
+		  else
+#endif
+		  /* If 'long long' exists and is the same as 'long', we parse
+		     "lln" into TYPE_COUNT_LONGINT_POINTER.  */
+		  if (flags >= 8)
+		    type = TYPE_COUNT_LONGINT_POINTER;
+		  else if (flags & 2)
+		    type = TYPE_COUNT_SCHAR_POINTER;
+		  else if (flags & 1)
+		    type = TYPE_COUNT_SHORT_POINTER;
+		  else
+		    type = TYPE_COUNT_INT_POINTER;
+		  break;
+		case '%':
+		  type = TYPE_NONE;
+		  break;
+		default:
+		  /* Unknown conversion character.  */
+		  goto error;
+		}
+	    }
+
+	    if (type != TYPE_NONE)
+	      {
+		dp->arg_index = arg_index;
+		if (dp->arg_index == ARG_NONE)
+		  {
+		    dp->arg_index = arg_posn++;
+		    if (dp->arg_index == ARG_NONE)
+		      /* arg_posn wrapped around.  */
+		      goto error;
+		  }
+		REGISTER_ARG (dp->arg_index, type);
+	      }
+	    dp->conversion = c;
+	    dp->dir_end = cp;
+	  }
+
+	  d->count++;
+	  if (d->count >= d_allocated)
+	    {
+	      size_t memory_size;
+	      DIRECTIVE *memory;
+
+	      d_allocated = xtimes (d_allocated, 2);
+	      memory_size = xtimes (d_allocated, sizeof (DIRECTIVE));
+	      if (size_overflow_p (memory_size))
+		/* Overflow, would lead to out of memory.  */
+		goto error;
+	      memory = (DIRECTIVE *) realloc (d->dir, memory_size);
+	      if (memory == NULL)
+		/* Out of memory.  */
+		goto error;
+	      d->dir = memory;
+	    }
+	}
+    }
+  d->dir[d->count].dir_start = cp;
+
+  d->max_width_length = max_width_length;
+  d->max_precision_length = max_precision_length;
+  return 0;
+
+error:
+  if (a->arg)
+    free (a->arg);
+  if (d->dir)
+    free (d->dir);
+  return -1;
+}
+
+#undef DIRECTIVES
+#undef DIRECTIVE
+#undef CHAR_T
+#undef PRINTF_PARSE
diff --git a/src/bin/m4/lib/printf-parse.h b/src/bin/m4/lib/printf-parse.h
new file mode 100644
index 0000000000..82a0d37cd7
--- /dev/null
+++ b/src/bin/m4/lib/printf-parse.h
@@ -0,0 +1,74 @@
+/* Parse printf format string.
+   Copyright (C) 1999, 2002-2003 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _PRINTF_PARSE_H
+#define _PRINTF_PARSE_H
+
+#include "printf-args.h"
+
+
+/* Flags */
+#define FLAG_GROUP	 1	/* ' flag */
+#define FLAG_LEFT	 2	/* - flag */
+#define FLAG_SHOWSIGN	 4	/* + flag */
+#define FLAG_SPACE	 8	/* space flag */
+#define FLAG_ALT	16	/* # flag */
+#define FLAG_ZERO	32
+
+/* arg_index value indicating that no argument is consumed.  */
+#define ARG_NONE	(~(size_t)0)
+
+/* A parsed directive.  */
+typedef struct
+{
+  const char* dir_start;
+  const char* dir_end;
+  int flags;
+  const char* width_start;
+  const char* width_end;
+  size_t width_arg_index;
+  const char* precision_start;
+  const char* precision_end;
+  size_t precision_arg_index;
+  char conversion; /* d i o u x X f e E g G c s p n U % but not C S */
+  size_t arg_index;
+}
+char_directive;
+
+/* A parsed format string.  */
+typedef struct
+{
+  size_t count;
+  char_directive *dir;
+  size_t max_width_length;
+  size_t max_precision_length;
+}
+char_directives;
+
+
+/* Parses the format string.  Fills in the number N of directives, and fills
+   in directives[0], ..., directives[N-1], and sets directives[N].dir_start
+   to the end of the format string.  Also fills in the arg_type fields of the
+   arguments and the needed count of arguments.  */
+#ifdef STATIC
+STATIC
+#else
+extern
+#endif
+int printf_parse (const char *format, char_directives *d, arguments *a);
+
+#endif /* _PRINTF_PARSE_H */
diff --git a/src/bin/m4/lib/quotearg.c b/src/bin/m4/lib/quotearg.c
new file mode 100644
index 0000000000..6f3ee9e86c
--- /dev/null
+++ b/src/bin/m4/lib/quotearg.c
@@ -0,0 +1,713 @@
+/* quotearg.c - quote arguments for output
+
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert <eggert@twinsun.com> */
+
+#include <config.h>
+
+#include "quotearg.h"
+
+#include "xalloc.h"
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+#define N_(msgid) msgid
+
+#if HAVE_WCHAR_H
+
+/* BSD/OS 4.1 wchar.h requires FILE and struct tm to be declared.  */
+# include <stdio.h>
+# include <time.h>
+
+# include <wchar.h>
+#endif
+
+#if !HAVE_MBRTOWC
+/* Disable multibyte processing entirely.  Since MB_CUR_MAX is 1, the
+   other macros are defined only for documentation and to satisfy C
+   syntax.  */
+# undef MB_CUR_MAX
+# define MB_CUR_MAX 1
+# undef mbstate_t
+# define mbstate_t int
+# define mbrtowc(pwc, s, n, ps) ((*(pwc) = *(s)) != 0)
+# define iswprint(wc) isprint ((unsigned char) (wc))
+# undef HAVE_MBSINIT
+#endif
+
+#if !defined mbsinit && !HAVE_MBSINIT
+# define mbsinit(ps) 1
+#endif
+
+#ifndef iswprint
+# if HAVE_WCTYPE_H
+#  include <wctype.h>
+# endif
+# if !defined iswprint && !HAVE_ISWPRINT
+#  define iswprint(wc) 1
+# endif
+#endif
+
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+#define INT_BITS (sizeof (int) * CHAR_BIT)
+
+struct quoting_options
+{
+  /* Basic quoting style.  */
+  enum quoting_style style;
+
+  /* Quote the characters indicated by this bit vector even if the
+     quoting style would not normally require them to be quoted.  */
+  unsigned int quote_these_too[(UCHAR_MAX / INT_BITS) + 1];
+};
+
+/* Names of quoting styles.  */
+char const *const quoting_style_args[] =
+{
+  "literal",
+  "shell",
+  "shell-always",
+  "c",
+  "escape",
+  "locale",
+  "clocale",
+  0
+};
+
+/* Correspondences to quoting style names.  */
+enum quoting_style const quoting_style_vals[] =
+{
+  literal_quoting_style,
+  shell_quoting_style,
+  shell_always_quoting_style,
+  c_quoting_style,
+  escape_quoting_style,
+  locale_quoting_style,
+  clocale_quoting_style
+};
+
+/* The default quoting options.  */
+static struct quoting_options default_quoting_options;
+
+/* Allocate a new set of quoting options, with contents initially identical
+   to O if O is not null, or to the default if O is null.
+   It is the caller's responsibility to free the result.  */
+struct quoting_options *
+clone_quoting_options (struct quoting_options *o)
+{
+  int e = errno;
+  struct quoting_options *p = xmemdup (o ? o : &default_quoting_options,
+				       sizeof *o);
+  errno = e;
+  return p;
+}
+
+/* Get the value of O's quoting style.  If O is null, use the default.  */
+enum quoting_style
+get_quoting_style (struct quoting_options *o)
+{
+  return (o ? o : &default_quoting_options)->style;
+}
+
+/* In O (or in the default if O is null),
+   set the value of the quoting style to S.  */
+void
+set_quoting_style (struct quoting_options *o, enum quoting_style s)
+{
+  (o ? o : &default_quoting_options)->style = s;
+}
+
+/* In O (or in the default if O is null),
+   set the value of the quoting options for character C to I.
+   Return the old value.  Currently, the only values defined for I are
+   0 (the default) and 1 (which means to quote the character even if
+   it would not otherwise be quoted).  */
+int
+set_char_quoting (struct quoting_options *o, char c, int i)
+{
+  unsigned char uc = c;
+  unsigned int *p =
+    (o ? o : &default_quoting_options)->quote_these_too + uc / INT_BITS;
+  int shift = uc % INT_BITS;
+  int r = (*p >> shift) & 1;
+  *p ^= ((i & 1) ^ r) << shift;
+  return r;
+}
+
+/* MSGID approximates a quotation mark.  Return its translation if it
+   has one; otherwise, return either it or "\"", depending on S.  */
+static char const *
+gettext_quote (char const *msgid, enum quoting_style s)
+{
+  char const *translation = _(msgid);
+  if (translation == msgid && s == clocale_quoting_style)
+    translation = "\"";
+  return translation;
+}
+
+/* Place into buffer BUFFER (of size BUFFERSIZE) a quoted version of
+   argument ARG (of size ARGSIZE), using QUOTING_STYLE and the
+   non-quoting-style part of O to control quoting.
+   Terminate the output with a null character, and return the written
+   size of the output, not counting the terminating null.
+   If BUFFERSIZE is too small to store the output string, return the
+   value that would have been returned had BUFFERSIZE been large enough.
+   If ARGSIZE is SIZE_MAX, use the string length of the argument for ARGSIZE.
+
+   This function acts like quotearg_buffer (BUFFER, BUFFERSIZE, ARG,
+   ARGSIZE, O), except it uses QUOTING_STYLE instead of the quoting
+   style specified by O, and O may not be null.  */
+
+static size_t
+quotearg_buffer_restyled (char *buffer, size_t buffersize,
+			  char const *arg, size_t argsize,
+			  enum quoting_style quoting_style,
+			  struct quoting_options const *o)
+{
+  size_t i;
+  size_t len = 0;
+  char const *quote_string = 0;
+  size_t quote_string_len = 0;
+  bool backslash_escapes = false;
+  bool unibyte_locale = MB_CUR_MAX == 1;
+
+#define STORE(c) \
+    do \
+      { \
+	if (len < buffersize) \
+	  buffer[len] = (c); \
+	len++; \
+      } \
+    while (0)
+
+  switch (quoting_style)
+    {
+    case c_quoting_style:
+      STORE ('"');
+      backslash_escapes = true;
+      quote_string = "\"";
+      quote_string_len = 1;
+      break;
+
+    case escape_quoting_style:
+      backslash_escapes = true;
+      break;
+
+    case locale_quoting_style:
+    case clocale_quoting_style:
+      {
+	/* TRANSLATORS:
+	   Get translations for open and closing quotation marks.
+
+	   The message catalog should translate "`" to a left
+	   quotation mark suitable for the locale, and similarly for
+	   "'".  If the catalog has no translation,
+	   locale_quoting_style quotes `like this', and
+	   clocale_quoting_style quotes "like this".
+
+	   For example, an American English Unicode locale should
+	   translate "`" to U+201C (LEFT DOUBLE QUOTATION MARK), and
+	   should translate "'" to U+201D (RIGHT DOUBLE QUOTATION
+	   MARK).  A British English Unicode locale should instead
+	   translate these to U+2018 (LEFT SINGLE QUOTATION MARK) and
+	   U+2019 (RIGHT SINGLE QUOTATION MARK), respectively.
+
+	   If you don't know what to put here, please see
+	   <http://en.wikipedia.org/wiki/Quotation_mark#Glyphs>
+	   and use glyphs suitable for your language.  */
+
+	char const *left = gettext_quote (N_("`"), quoting_style);
+	char const *right = gettext_quote (N_("'"), quoting_style);
+	for (quote_string = left; *quote_string; quote_string++)
+	  STORE (*quote_string);
+	backslash_escapes = true;
+	quote_string = right;
+	quote_string_len = strlen (quote_string);
+      }
+      break;
+
+    case shell_always_quoting_style:
+      STORE ('\'');
+      quote_string = "'";
+      quote_string_len = 1;
+      break;
+
+    default:
+      break;
+    }
+
+  for (i = 0;  ! (argsize == SIZE_MAX ? arg[i] == '\0' : i == argsize);  i++)
+    {
+      unsigned char c;
+      unsigned char esc;
+
+      if (backslash_escapes
+	  && quote_string_len
+	  && i + quote_string_len <= argsize
+	  && memcmp (arg + i, quote_string, quote_string_len) == 0)
+	STORE ('\\');
+
+      c = arg[i];
+      switch (c)
+	{
+	case '\0':
+	  if (backslash_escapes)
+	    {
+	      STORE ('\\');
+	      STORE ('0');
+	      STORE ('0');
+	      c = '0';
+	    }
+	  break;
+
+	case '?':
+	  switch (quoting_style)
+	    {
+	    case shell_quoting_style:
+	      goto use_shell_always_quoting_style;
+
+	    case c_quoting_style:
+	      if (i + 2 < argsize && arg[i + 1] == '?')
+		switch (arg[i + 2])
+		  {
+		  case '!': case '\'':
+		  case '(': case ')': case '-': case '/':
+		  case '<': case '=': case '>':
+		    /* Escape the second '?' in what would otherwise be
+		       a trigraph.  */
+		    c = arg[i + 2];
+		    i += 2;
+		    STORE ('?');
+		    STORE ('\\');
+		    STORE ('?');
+		    break;
+
+		  default:
+		    break;
+		  }
+	      break;
+
+	    default:
+	      break;
+	    }
+	  break;
+
+	case '\a': esc = 'a'; goto c_escape;
+	case '\b': esc = 'b'; goto c_escape;
+	case '\f': esc = 'f'; goto c_escape;
+	case '\n': esc = 'n'; goto c_and_shell_escape;
+	case '\r': esc = 'r'; goto c_and_shell_escape;
+	case '\t': esc = 't'; goto c_and_shell_escape;
+	case '\v': esc = 'v'; goto c_escape;
+	case '\\': esc = c; goto c_and_shell_escape;
+
+	c_and_shell_escape:
+	  if (quoting_style == shell_quoting_style)
+	    goto use_shell_always_quoting_style;
+	c_escape:
+	  if (backslash_escapes)
+	    {
+	      c = esc;
+	      goto store_escape;
+	    }
+	  break;
+
+	case '{': case '}': /* sometimes special if isolated */
+	  if (! (argsize == SIZE_MAX ? arg[1] == '\0' : argsize == 1))
+	    break;
+	  /* Fall through.  */
+	case '#': case '~':
+	  if (i != 0)
+	    break;
+	  /* Fall through.  */
+	case ' ':
+	case '!': /* special in bash */
+	case '"': case '$': case '&':
+	case '(': case ')': case '*': case ';':
+	case '<':
+	case '=': /* sometimes special in 0th or (with "set -k") later args */
+	case '>': case '[':
+	case '^': /* special in old /bin/sh, e.g. SunOS 4.1.4 */
+	case '`': case '|':
+	  /* A shell special character.  In theory, '$' and '`' could
+	     be the first bytes of multibyte characters, which means
+	     we should check them with mbrtowc, but in practice this
+	     doesn't happen so it's not worth worrying about.  */
+	  if (quoting_style == shell_quoting_style)
+	    goto use_shell_always_quoting_style;
+	  break;
+
+	case '\'':
+	  switch (quoting_style)
+	    {
+	    case shell_quoting_style:
+	      goto use_shell_always_quoting_style;
+
+	    case shell_always_quoting_style:
+	      STORE ('\'');
+	      STORE ('\\');
+	      STORE ('\'');
+	      break;
+
+	    default:
+	      break;
+	    }
+	  break;
+
+	case '%': case '+': case ',': case '-': case '.': case '/':
+	case '0': case '1': case '2': case '3': case '4': case '5':
+	case '6': case '7': case '8': case '9': case ':':
+	case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
+	case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
+	case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
+	case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
+	case 'Y': case 'Z': case ']': case '_': case 'a': case 'b':
+	case 'c': case 'd': case 'e': case 'f': case 'g': case 'h':
+	case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
+	case 'o': case 'p': case 'q': case 'r': case 's': case 't':
+	case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
+	  /* These characters don't cause problems, no matter what the
+	     quoting style is.  They cannot start multibyte sequences.  */
+	  break;
+
+	default:
+	  /* If we have a multibyte sequence, copy it until we reach
+	     its end, find an error, or come back to the initial shift
+	     state.  For C-like styles, if the sequence has
+	     unprintable characters, escape the whole sequence, since
+	     we can't easily escape single characters within it.  */
+	  {
+	    /* Length of multibyte sequence found so far.  */
+	    size_t m;
+
+	    bool printable;
+
+	    if (unibyte_locale)
+	      {
+		m = 1;
+		printable = isprint (c) != 0;
+	      }
+	    else
+	      {
+		mbstate_t mbstate;
+		memset (&mbstate, 0, sizeof mbstate);
+
+		m = 0;
+		printable = true;
+		if (argsize == SIZE_MAX)
+		  argsize = strlen (arg);
+
+		do
+		  {
+		    wchar_t w;
+		    size_t bytes = mbrtowc (&w, &arg[i + m],
+					    argsize - (i + m), &mbstate);
+		    if (bytes == 0)
+		      break;
+		    else if (bytes == (size_t) -1)
+		      {
+			printable = false;
+			break;
+		      }
+		    else if (bytes == (size_t) -2)
+		      {
+			printable = false;
+			while (i + m < argsize && arg[i + m])
+			  m++;
+			break;
+		      }
+		    else
+		      {
+			/* Work around a bug with older shells that "see" a '\'
+			   that is really the 2nd byte of a multibyte character.
+			   In practice the problem is limited to ASCII
+			   chars >= '@' that are shell special chars.  */
+			if ('[' == 0x5b && quoting_style == shell_quoting_style)
+			  {
+			    size_t j;
+			    for (j = 1; j < bytes; j++)
+			      switch (arg[i + m + j])
+				{
+				case '[': case '\\': case '^':
+				case '`': case '|':
+				  goto use_shell_always_quoting_style;
+
+				default:
+				  break;
+				}
+			  }
+
+			if (! iswprint (w))
+			  printable = false;
+			m += bytes;
+		      }
+		  }
+		while (! mbsinit (&mbstate));
+	      }
+
+	    if (1 < m || (backslash_escapes && ! printable))
+	      {
+		/* Output a multibyte sequence, or an escaped
+		   unprintable unibyte character.  */
+		size_t ilim = i + m;
+
+		for (;;)
+		  {
+		    if (backslash_escapes && ! printable)
+		      {
+			STORE ('\\');
+			STORE ('0' + (c >> 6));
+			STORE ('0' + ((c >> 3) & 7));
+			c = '0' + (c & 7);
+		      }
+		    if (ilim <= i + 1)
+		      break;
+		    STORE (c);
+		    c = arg[++i];
+		  }
+
+		goto store_c;
+	      }
+	  }
+	}
+
+      if (! (backslash_escapes
+	     && o->quote_these_too[c / INT_BITS] & (1 << (c % INT_BITS))))
+	goto store_c;
+
+    store_escape:
+      STORE ('\\');
+
+    store_c:
+      STORE (c);
+    }
+
+  if (i == 0 && quoting_style == shell_quoting_style)
+    goto use_shell_always_quoting_style;
+
+  if (quote_string)
+    for (; *quote_string; quote_string++)
+      STORE (*quote_string);
+
+  if (len < buffersize)
+    buffer[len] = '\0';
+  return len;
+
+ use_shell_always_quoting_style:
+  return quotearg_buffer_restyled (buffer, buffersize, arg, argsize,
+				   shell_always_quoting_style, o);
+}
+
+/* Place into buffer BUFFER (of size BUFFERSIZE) a quoted version of
+   argument ARG (of size ARGSIZE), using O to control quoting.
+   If O is null, use the default.
+   Terminate the output with a null character, and return the written
+   size of the output, not counting the terminating null.
+   If BUFFERSIZE is too small to store the output string, return the
+   value that would have been returned had BUFFERSIZE been large enough.
+   If ARGSIZE is SIZE_MAX, use the string length of the argument for
+   ARGSIZE.  */
+size_t
+quotearg_buffer (char *buffer, size_t buffersize,
+		 char const *arg, size_t argsize,
+		 struct quoting_options const *o)
+{
+  struct quoting_options const *p = o ? o : &default_quoting_options;
+  int e = errno;
+  size_t r = quotearg_buffer_restyled (buffer, buffersize, arg, argsize,
+				       p->style, p);
+  errno = e;
+  return r;
+}
+
+/* Like quotearg_buffer (..., ARG, ARGSIZE, O), except return newly
+   allocated storage containing the quoted string.  */
+char *
+quotearg_alloc (char const *arg, size_t argsize,
+		struct quoting_options const *o)
+{
+  int e = errno;
+  size_t bufsize = quotearg_buffer (0, 0, arg, argsize, o) + 1;
+  char *buf = xcharalloc (bufsize);
+  quotearg_buffer (buf, bufsize, arg, argsize, o);
+  errno = e;
+  return buf;
+}
+
+/* A storage slot with size and pointer to a value.  */
+struct slotvec
+{
+  size_t size;
+  char *val;
+};
+
+/* Preallocate a slot 0 buffer, so that the caller can always quote
+   one small component of a "memory exhausted" message in slot 0.  */
+static char slot0[256];
+static unsigned int nslots = 1;
+static struct slotvec slotvec0 = {sizeof slot0, slot0};
+static struct slotvec *slotvec = &slotvec0;
+
+void
+quotearg_free (void)
+{
+  struct slotvec *sv = slotvec;
+  unsigned int i;
+  for (i = 1; i < nslots; i++)
+    free (sv[i].val);
+  if (sv[0].val != slot0)
+    {
+      free (sv[0].val);
+      slotvec0.size = sizeof slot0;
+      slotvec0.val = slot0;
+    }
+  if (sv != &slotvec0)
+    {
+      free (sv);
+      slotvec = &slotvec0;
+    }
+  nslots = 1;
+}
+
+/* Use storage slot N to return a quoted version of argument ARG.
+   ARG is of size ARGSIZE, but if that is SIZE_MAX, ARG is a
+   null-terminated string.
+   OPTIONS specifies the quoting options.
+   The returned value points to static storage that can be
+   reused by the next call to this function with the same value of N.
+   N must be nonnegative.  N is deliberately declared with type "int"
+   to allow for future extensions (using negative values).  */
+static char *
+quotearg_n_options (int n, char const *arg, size_t argsize,
+		    struct quoting_options const *options)
+{
+  int e = errno;
+
+  unsigned int n0 = n;
+  struct slotvec *sv = slotvec;
+
+  if (n < 0)
+    abort ();
+
+  if (nslots <= n0)
+    {
+      /* FIXME: technically, the type of n1 should be `unsigned int',
+	 but that evokes an unsuppressible warning from gcc-4.0.1 and
+	 older.  If gcc ever provides an option to suppress that warning,
+	 revert to the original type, so that the test in xalloc_oversized
+	 is once again performed only at compile time.  */
+      size_t n1 = n0 + 1;
+      bool preallocated = (sv == &slotvec0);
+
+      if (xalloc_oversized (n1, sizeof *sv))
+	xalloc_die ();
+
+      slotvec = sv = xrealloc (preallocated ? NULL : sv, n1 * sizeof *sv);
+      if (preallocated)
+	*sv = slotvec0;
+      memset (sv + nslots, 0, (n1 - nslots) * sizeof *sv);
+      nslots = n1;
+    }
+
+  {
+    size_t size = sv[n].size;
+    char *val = sv[n].val;
+    size_t qsize = quotearg_buffer (val, size, arg, argsize, options);
+
+    if (size <= qsize)
+      {
+	sv[n].size = size = qsize + 1;
+	if (val != slot0)
+	  free (val);
+	sv[n].val = val = xcharalloc (size);
+	quotearg_buffer (val, size, arg, argsize, options);
+      }
+
+    errno = e;
+    return val;
+  }
+}
+
+char *
+quotearg_n (int n, char const *arg)
+{
+  return quotearg_n_options (n, arg, SIZE_MAX, &default_quoting_options);
+}
+
+char *
+quotearg (char const *arg)
+{
+  return quotearg_n (0, arg);
+}
+
+/* Return quoting options for STYLE, with no extra quoting.  */
+static struct quoting_options
+quoting_options_from_style (enum quoting_style style)
+{
+  struct quoting_options o;
+  o.style = style;
+  memset (o.quote_these_too, 0, sizeof o.quote_these_too);
+  return o;
+}
+
+char *
+quotearg_n_style (int n, enum quoting_style s, char const *arg)
+{
+  struct quoting_options const o = quoting_options_from_style (s);
+  return quotearg_n_options (n, arg, SIZE_MAX, &o);
+}
+
+char *
+quotearg_n_style_mem (int n, enum quoting_style s,
+		      char const *arg, size_t argsize)
+{
+  struct quoting_options const o = quoting_options_from_style (s);
+  return quotearg_n_options (n, arg, argsize, &o);
+}
+
+char *
+quotearg_style (enum quoting_style s, char const *arg)
+{
+  return quotearg_n_style (0, s, arg);
+}
+
+char *
+quotearg_char (char const *arg, char ch)
+{
+  struct quoting_options options;
+  options = default_quoting_options;
+  set_char_quoting (&options, ch, 1);
+  return quotearg_n_options (0, arg, SIZE_MAX, &options);
+}
+
+char *
+quotearg_colon (char const *arg)
+{
+  return quotearg_char (arg, ':');
+}
diff --git a/src/bin/m4/lib/quotearg.h b/src/bin/m4/lib/quotearg.h
new file mode 100644
index 0000000000..4887df3b6d
--- /dev/null
+++ b/src/bin/m4/lib/quotearg.h
@@ -0,0 +1,140 @@
+/* quotearg.h - quote arguments for output
+
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert <eggert@twinsun.com> */
+
+#ifndef QUOTEARG_H_
+# define QUOTEARG_H_ 1
+
+# include <stddef.h>
+
+/* Basic quoting styles.  */
+enum quoting_style
+  {
+    /* Output names as-is (ls --quoting-style=literal).  */
+    literal_quoting_style,
+
+    /* Quote names for the shell if they contain shell metacharacters
+       or would cause ambiguous output (ls --quoting-style=shell).  */
+    shell_quoting_style,
+
+    /* Quote names for the shell, even if they would normally not
+       require quoting (ls --quoting-style=shell-always).  */
+    shell_always_quoting_style,
+
+    /* Quote names as for a C language string (ls --quoting-style=c).  */
+    c_quoting_style,
+
+    /* Like c_quoting_style except omit the surrounding double-quote
+       characters (ls --quoting-style=escape).  */
+    escape_quoting_style,
+
+    /* Like clocale_quoting_style, but quote `like this' instead of
+       "like this" in the default C locale (ls --quoting-style=locale).  */
+    locale_quoting_style,
+
+    /* Like c_quoting_style except use quotation marks appropriate for
+       the locale (ls --quoting-style=clocale).  */
+    clocale_quoting_style
+  };
+
+/* For now, --quoting-style=literal is the default, but this may change.  */
+# ifndef DEFAULT_QUOTING_STYLE
+#  define DEFAULT_QUOTING_STYLE literal_quoting_style
+# endif
+
+/* Names of quoting styles and their corresponding values.  */
+extern char const *const quoting_style_args[];
+extern enum quoting_style const quoting_style_vals[];
+
+struct quoting_options;
+
+/* The functions listed below set and use a hidden variable
+   that contains the default quoting style options.  */
+
+/* Allocate a new set of quoting options, with contents initially identical
+   to O if O is not null, or to the default if O is null.
+   It is the caller's responsibility to free the result.  */
+struct quoting_options *clone_quoting_options (struct quoting_options *o);
+
+/* Get the value of O's quoting style.  If O is null, use the default.  */
+enum quoting_style get_quoting_style (struct quoting_options *o);
+
+/* In O (or in the default if O is null),
+   set the value of the quoting style to S.  */
+void set_quoting_style (struct quoting_options *o, enum quoting_style s);
+
+/* In O (or in the default if O is null),
+   set the value of the quoting options for character C to I.
+   Return the old value.  Currently, the only values defined for I are
+   0 (the default) and 1 (which means to quote the character even if
+   it would not otherwise be quoted).  */
+int set_char_quoting (struct quoting_options *o, char c, int i);
+
+/* Place into buffer BUFFER (of size BUFFERSIZE) a quoted version of
+   argument ARG (of size ARGSIZE), using O to control quoting.
+   If O is null, use the default.
+   Terminate the output with a null character, and return the written
+   size of the output, not counting the terminating null.
+   If BUFFERSIZE is too small to store the output string, return the
+   value that would have been returned had BUFFERSIZE been large enough.
+   If ARGSIZE is -1, use the string length of the argument for ARGSIZE.  */
+size_t quotearg_buffer (char *buffer, size_t buffersize,
+			char const *arg, size_t argsize,
+			struct quoting_options const *o);
+
+/* Like quotearg_buffer, except return the result in a newly allocated
+   buffer.  It is the caller's responsibility to free the result.  */
+char *quotearg_alloc (char const *arg, size_t argsize,
+		      struct quoting_options const *o);
+
+/* Use storage slot N to return a quoted version of the string ARG.
+   Use the default quoting options.
+   The returned value points to static storage that can be
+   reused by the next call to this function with the same value of N.
+   N must be nonnegative.  */
+char *quotearg_n (int n, char const *arg);
+
+/* Equivalent to quotearg_n (0, ARG).  */
+char *quotearg (char const *arg);
+
+/* Use style S and storage slot N to return a quoted version of the string ARG.
+   This is like quotearg_n (N, ARG), except that it uses S with no other
+   options to specify the quoting method.  */
+char *quotearg_n_style (int n, enum quoting_style s, char const *arg);
+
+/* Use style S and storage slot N to return a quoted version of the
+   argument ARG of size ARGSIZE.  This is like quotearg_n_style
+   (N, S, ARG), except it can quote null bytes.  */
+char *quotearg_n_style_mem (int n, enum quoting_style s,
+			    char const *arg, size_t argsize);
+
+/* Equivalent to quotearg_n_style (0, S, ARG).  */
+char *quotearg_style (enum quoting_style s, char const *arg);
+
+/* Like quotearg (ARG), except also quote any instances of CH.  */
+char *quotearg_char (char const *arg, char ch);
+
+/* Equivalent to quotearg_char (ARG, ':').  */
+char *quotearg_colon (char const *arg);
+
+/* Free any dynamically allocated memory.  */
+void quotearg_free (void);
+
+#endif /* !QUOTEARG_H_ */
diff --git a/src/bin/m4/lib/regcomp.c b/src/bin/m4/lib/regcomp.c
new file mode 100644
index 0000000000..6e317f5134
--- /dev/null
+++ b/src/bin/m4/lib/regcomp.c
@@ -0,0 +1,3858 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002,2003,2004,2005,2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
+					  size_t length, reg_syntax_t syntax);
+static void re_compile_fastmap_iter (regex_t *bufp,
+				     const re_dfastate_t *init_state,
+				     char *fastmap);
+static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len);
+#ifdef RE_ENABLE_I18N
+static void free_charset (re_charset_t *cset);
+#endif /* RE_ENABLE_I18N */
+static void free_workarea_compile (regex_t *preg);
+static reg_errcode_t create_initial_state (re_dfa_t *dfa);
+#ifdef RE_ENABLE_I18N
+static void optimize_utf8 (re_dfa_t *dfa);
+#endif
+static reg_errcode_t analyze (regex_t *preg);
+static reg_errcode_t preorder (bin_tree_t *root,
+			       reg_errcode_t (fn (void *, bin_tree_t *)),
+			       void *extra);
+static reg_errcode_t postorder (bin_tree_t *root,
+				reg_errcode_t (fn (void *, bin_tree_t *)),
+				void *extra);
+static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node);
+static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node);
+static bin_tree_t *lower_subexp (reg_errcode_t *err, regex_t *preg,
+				 bin_tree_t *node);
+static reg_errcode_t calc_first (void *extra, bin_tree_t *node);
+static reg_errcode_t calc_next (void *extra, bin_tree_t *node);
+static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node);
+static Idx duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int constraint);
+static Idx search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
+				   unsigned int constraint);
+static reg_errcode_t calc_eclosure (re_dfa_t *dfa);
+static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa,
+					 Idx node, bool root);
+static reg_errcode_t calc_inveclosure (re_dfa_t *dfa);
+static Idx fetch_number (re_string_t *input, re_token_t *token,
+			 reg_syntax_t syntax);
+static int peek_token (re_token_t *token, re_string_t *input,
+			reg_syntax_t syntax) internal_function;
+static bin_tree_t *parse (re_string_t *regexp, regex_t *preg,
+			  reg_syntax_t syntax, reg_errcode_t *err);
+static bin_tree_t *parse_reg_exp (re_string_t *regexp, regex_t *preg,
+				  re_token_t *token, reg_syntax_t syntax,
+				  Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_branch (re_string_t *regexp, regex_t *preg,
+				 re_token_t *token, reg_syntax_t syntax,
+				 Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_expression (re_string_t *regexp, regex_t *preg,
+				     re_token_t *token, reg_syntax_t syntax,
+				     Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_sub_exp (re_string_t *regexp, regex_t *preg,
+				  re_token_t *token, reg_syntax_t syntax,
+				  Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_dup_op (bin_tree_t *dup_elem, re_string_t *regexp,
+				 re_dfa_t *dfa, re_token_t *token,
+				 reg_syntax_t syntax, reg_errcode_t *err);
+static bin_tree_t *parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa,
+				      re_token_t *token, reg_syntax_t syntax,
+				      reg_errcode_t *err);
+static reg_errcode_t parse_bracket_element (bracket_elem_t *elem,
+					    re_string_t *regexp,
+					    re_token_t *token, int token_len,
+					    re_dfa_t *dfa,
+					    reg_syntax_t syntax,
+					    bool accept_hyphen);
+static reg_errcode_t parse_bracket_symbol (bracket_elem_t *elem,
+					  re_string_t *regexp,
+					  re_token_t *token);
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t build_equiv_class (bitset_t sbcset,
+					re_charset_t *mbcset,
+					Idx *equiv_class_alloc,
+					const unsigned char *name);
+static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
+				      bitset_t sbcset,
+				      re_charset_t *mbcset,
+				      Idx *char_class_alloc,
+				      const unsigned char *class_name,
+				      reg_syntax_t syntax);
+#else  /* not RE_ENABLE_I18N */
+static reg_errcode_t build_equiv_class (bitset_t sbcset,
+					const unsigned char *name);
+static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
+				      bitset_t sbcset,
+				      const unsigned char *class_name,
+				      reg_syntax_t syntax);
+#endif /* not RE_ENABLE_I18N */
+static bin_tree_t *build_charclass_op (re_dfa_t *dfa,
+				       RE_TRANSLATE_TYPE trans,
+				       const unsigned char *class_name,
+				       const unsigned char *extra,
+				       bool non_match, reg_errcode_t *err);
+static bin_tree_t *create_tree (re_dfa_t *dfa,
+				bin_tree_t *left, bin_tree_t *right,
+				re_token_type_t type);
+static bin_tree_t *create_token_tree (re_dfa_t *dfa,
+				      bin_tree_t *left, bin_tree_t *right,
+				      const re_token_t *token);
+static bin_tree_t *duplicate_tree (const bin_tree_t *src, re_dfa_t *dfa);
+static void free_token (re_token_t *node);
+static reg_errcode_t free_tree (void *extra, bin_tree_t *node);
+static reg_errcode_t mark_opt_subexp (void *extra, bin_tree_t *node);
+
+/* This table gives an error message for each of the error codes listed
+   in regex.h.  Obviously the order here has to be same as there.
+   POSIX doesn't require that we do anything for REG_NOERROR,
+   but why not be nice?  */
+
+static const char __re_error_msgid[] =
+  {
+#define REG_NOERROR_IDX	0
+    gettext_noop ("Success")	/* REG_NOERROR */
+    "\0"
+#define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success")
+    gettext_noop ("No match")	/* REG_NOMATCH */
+    "\0"
+#define REG_BADPAT_IDX	(REG_NOMATCH_IDX + sizeof "No match")
+    gettext_noop ("Invalid regular expression") /* REG_BADPAT */
+    "\0"
+#define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression")
+    gettext_noop ("Invalid collation character") /* REG_ECOLLATE */
+    "\0"
+#define REG_ECTYPE_IDX	(REG_ECOLLATE_IDX + sizeof "Invalid collation character")
+    gettext_noop ("Invalid character class name") /* REG_ECTYPE */
+    "\0"
+#define REG_EESCAPE_IDX	(REG_ECTYPE_IDX + sizeof "Invalid character class name")
+    gettext_noop ("Trailing backslash") /* REG_EESCAPE */
+    "\0"
+#define REG_ESUBREG_IDX	(REG_EESCAPE_IDX + sizeof "Trailing backslash")
+    gettext_noop ("Invalid back reference") /* REG_ESUBREG */
+    "\0"
+#define REG_EBRACK_IDX	(REG_ESUBREG_IDX + sizeof "Invalid back reference")
+    gettext_noop ("Unmatched [ or [^")	/* REG_EBRACK */
+    "\0"
+#define REG_EPAREN_IDX	(REG_EBRACK_IDX + sizeof "Unmatched [ or [^")
+    gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */
+    "\0"
+#define REG_EBRACE_IDX	(REG_EPAREN_IDX + sizeof "Unmatched ( or \\(")
+    gettext_noop ("Unmatched \\{") /* REG_EBRACE */
+    "\0"
+#define REG_BADBR_IDX	(REG_EBRACE_IDX + sizeof "Unmatched \\{")
+    gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */
+    "\0"
+#define REG_ERANGE_IDX	(REG_BADBR_IDX + sizeof "Invalid content of \\{\\}")
+    gettext_noop ("Invalid range end")	/* REG_ERANGE */
+    "\0"
+#define REG_ESPACE_IDX	(REG_ERANGE_IDX + sizeof "Invalid range end")
+    gettext_noop ("Memory exhausted") /* REG_ESPACE */
+    "\0"
+#define REG_BADRPT_IDX	(REG_ESPACE_IDX + sizeof "Memory exhausted")
+    gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */
+    "\0"
+#define REG_EEND_IDX	(REG_BADRPT_IDX + sizeof "Invalid preceding regular expression")
+    gettext_noop ("Premature end of regular expression") /* REG_EEND */
+    "\0"
+#define REG_ESIZE_IDX	(REG_EEND_IDX + sizeof "Premature end of regular expression")
+    gettext_noop ("Regular expression too big") /* REG_ESIZE */
+    "\0"
+#define REG_ERPAREN_IDX	(REG_ESIZE_IDX + sizeof "Regular expression too big")
+    gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
+  };
+
+static const size_t __re_error_msgid_idx[] =
+  {
+    REG_NOERROR_IDX,
+    REG_NOMATCH_IDX,
+    REG_BADPAT_IDX,
+    REG_ECOLLATE_IDX,
+    REG_ECTYPE_IDX,
+    REG_EESCAPE_IDX,
+    REG_ESUBREG_IDX,
+    REG_EBRACK_IDX,
+    REG_EPAREN_IDX,
+    REG_EBRACE_IDX,
+    REG_BADBR_IDX,
+    REG_ERANGE_IDX,
+    REG_ESPACE_IDX,
+    REG_BADRPT_IDX,
+    REG_EEND_IDX,
+    REG_ESIZE_IDX,
+    REG_ERPAREN_IDX
+  };
+
+/* Entry points for GNU code.  */
+
+/* re_compile_pattern is the GNU regular expression compiler: it
+   compiles PATTERN (of length LENGTH) and puts the result in BUFP.
+   Returns 0 if the pattern was valid, otherwise an error string.
+
+   Assumes the `allocated' (and perhaps `buffer') and `translate' fields
+   are set in BUFP on entry.  */
+
+#ifdef _LIBC
+const char *
+re_compile_pattern (pattern, length, bufp)
+    const char *pattern;
+    size_t length;
+    struct re_pattern_buffer *bufp;
+#else /* size_t might promote */
+const char *
+re_compile_pattern (const char *pattern, size_t length,
+		    struct re_pattern_buffer *bufp)
+#endif
+{
+  reg_errcode_t ret;
+
+  /* And GNU code determines whether or not to get register information
+     by passing null for the REGS argument to re_match, etc., not by
+     setting no_sub, unless RE_NO_SUB is set.  */
+  bufp->no_sub = !!(re_syntax_options & RE_NO_SUB);
+
+  /* Match anchors at newline.  */
+  bufp->newline_anchor = 1;
+
+  ret = re_compile_internal (bufp, pattern, length, re_syntax_options);
+
+  if (!ret)
+    return NULL;
+  return gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
+}
+#ifdef _LIBC
+weak_alias (__re_compile_pattern, re_compile_pattern)
+#endif
+
+/* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
+   also be assigned to arbitrarily: each pattern buffer stores its own
+   syntax, so it can be changed between regex compilations.  */
+/* This has no initializer because initialized variables in Emacs
+   become read-only after dumping.  */
+reg_syntax_t re_syntax_options;
+
+
+/* Specify the precise syntax of regexps for compilation.  This provides
+   for compatibility for various utilities which historically have
+   different, incompatible syntaxes.
+
+   The argument SYNTAX is a bit mask comprised of the various bits
+   defined in regex.h.  We return the old syntax.  */
+
+reg_syntax_t
+re_set_syntax (syntax)
+    reg_syntax_t syntax;
+{
+  reg_syntax_t ret = re_syntax_options;
+
+  re_syntax_options = syntax;
+  return ret;
+}
+#ifdef _LIBC
+weak_alias (__re_set_syntax, re_set_syntax)
+#endif
+
+int
+re_compile_fastmap (bufp)
+    struct re_pattern_buffer *bufp;
+{
+  re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+  char *fastmap = bufp->fastmap;
+
+  memset (fastmap, '\0', sizeof (char) * SBC_MAX);
+  re_compile_fastmap_iter (bufp, dfa->init_state, fastmap);
+  if (dfa->init_state != dfa->init_state_word)
+    re_compile_fastmap_iter (bufp, dfa->init_state_word, fastmap);
+  if (dfa->init_state != dfa->init_state_nl)
+    re_compile_fastmap_iter (bufp, dfa->init_state_nl, fastmap);
+  if (dfa->init_state != dfa->init_state_begbuf)
+    re_compile_fastmap_iter (bufp, dfa->init_state_begbuf, fastmap);
+  bufp->fastmap_accurate = 1;
+  return 0;
+}
+#ifdef _LIBC
+weak_alias (__re_compile_fastmap, re_compile_fastmap)
+#endif
+
+static inline void
+__attribute ((always_inline))
+re_set_fastmap (char *fastmap, bool icase, int ch)
+{
+  fastmap[ch] = 1;
+  if (icase)
+    fastmap[tolower (ch)] = 1;
+}
+
+/* Helper function for re_compile_fastmap.
+   Compile fastmap for the initial_state INIT_STATE.  */
+
+static void
+re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
+			 char *fastmap)
+{
+  re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+  Idx node_cnt;
+  bool icase = (dfa->mb_cur_max == 1 && (bufp->syntax & RE_ICASE));
+  for (node_cnt = 0; node_cnt < init_state->nodes.nelem; ++node_cnt)
+    {
+      Idx node = init_state->nodes.elems[node_cnt];
+      re_token_type_t type = dfa->nodes[node].type;
+
+      if (type == CHARACTER)
+	{
+	  re_set_fastmap (fastmap, icase, dfa->nodes[node].opr.c);
+#ifdef RE_ENABLE_I18N
+	  if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
+	    {
+	      unsigned char buf[MB_LEN_MAX];
+	      unsigned char *p;
+	      wchar_t wc;
+	      mbstate_t state;
+
+	      p = buf;
+	      *p++ = dfa->nodes[node].opr.c;
+	      while (++node < dfa->nodes_len
+		     &&	dfa->nodes[node].type == CHARACTER
+		     && dfa->nodes[node].mb_partial)
+		*p++ = dfa->nodes[node].opr.c;
+	      memset (&state, '\0', sizeof (state));
+	      if (mbrtowc (&wc, (const char *) buf, p - buf,
+			   &state) == p - buf
+		  && (__wcrtomb ((char *) buf, towlower (wc), &state)
+		      != (size_t) -1))
+		re_set_fastmap (fastmap, false, buf[0]);
+	    }
+#endif
+	}
+      else if (type == SIMPLE_BRACKET)
+	{
+	  int i, ch;
+	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+	    {
+	      int j;
+	      bitset_word_t w = dfa->nodes[node].opr.sbcset[i];
+	      for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+		if (w & ((bitset_word_t) 1 << j))
+		  re_set_fastmap (fastmap, icase, ch);
+	    }
+	}
+#ifdef RE_ENABLE_I18N
+      else if (type == COMPLEX_BRACKET)
+	{
+	  Idx i;
+	  re_charset_t *cset = dfa->nodes[node].opr.mbcset;
+	  if (cset->non_match || cset->ncoll_syms || cset->nequiv_classes
+	      || cset->nranges || cset->nchar_classes)
+	    {
+# ifdef _LIBC
+	      if (_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES) != 0)
+		{
+		  /* In this case we want to catch the bytes which are
+		     the first byte of any collation elements.
+		     e.g. In da_DK, we want to catch 'a' since "aa"
+			  is a valid collation element, and don't catch
+			  'b' since 'b' is the only collation element
+			  which starts from 'b'.  */
+		  const int32_t *table = (const int32_t *)
+		    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+		  for (i = 0; i < SBC_MAX; ++i)
+		    if (table[i] < 0)
+		      re_set_fastmap (fastmap, icase, i);
+		}
+# else
+	      if (dfa->mb_cur_max > 1)
+		for (i = 0; i < SBC_MAX; ++i)
+		  if (__btowc (i) == WEOF)
+		    re_set_fastmap (fastmap, icase, i);
+# endif /* not _LIBC */
+	    }
+	  for (i = 0; i < cset->nmbchars; ++i)
+	    {
+	      char buf[256];
+	      mbstate_t state;
+	      memset (&state, '\0', sizeof (state));
+	      if (__wcrtomb (buf, cset->mbchars[i], &state) != (size_t) -1)
+		re_set_fastmap (fastmap, icase, *(unsigned char *) buf);
+	      if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
+		{
+		  if (__wcrtomb (buf, towlower (cset->mbchars[i]), &state)
+		      != (size_t) -1)
+		    re_set_fastmap (fastmap, false, *(unsigned char *) buf);
+		}
+	    }
+	}
+#endif /* RE_ENABLE_I18N */
+      else if (type == OP_PERIOD
+#ifdef RE_ENABLE_I18N
+	       || type == OP_UTF8_PERIOD
+#endif /* RE_ENABLE_I18N */
+	       || type == END_OF_RE)
+	{
+	  memset (fastmap, '\1', sizeof (char) * SBC_MAX);
+	  if (type == END_OF_RE)
+	    bufp->can_be_null = 1;
+	  return;
+	}
+    }
+}
+
+/* Entry point for POSIX code.  */
+/* regcomp takes a regular expression as a string and compiles it.
+
+   PREG is a regex_t *.  We do not expect any fields to be initialized,
+   since POSIX says we shouldn't.  Thus, we set
+
+     `buffer' to the compiled pattern;
+     `used' to the length of the compiled pattern;
+     `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
+       REG_EXTENDED bit in CFLAGS is set; otherwise, to
+       RE_SYNTAX_POSIX_BASIC;
+     `newline_anchor' to REG_NEWLINE being set in CFLAGS;
+     `fastmap' to an allocated space for the fastmap;
+     `fastmap_accurate' to zero;
+     `re_nsub' to the number of subexpressions in PATTERN.
+
+   PATTERN is the address of the pattern string.
+
+   CFLAGS is a series of bits which affect compilation.
+
+     If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
+     use POSIX basic syntax.
+
+     If REG_NEWLINE is set, then . and [^...] don't match newline.
+     Also, regexec will try a match beginning after every newline.
+
+     If REG_ICASE is set, then we considers upper- and lowercase
+     versions of letters to be equivalent when matching.
+
+     If REG_NOSUB is set, then when PREG is passed to regexec, that
+     routine will report only success or failure, and nothing about the
+     registers.
+
+   It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
+   the return codes and their meanings.)  */
+
+int
+regcomp (preg, pattern, cflags)
+    regex_t *__restrict preg;
+    const char *__restrict pattern;
+    int cflags;
+{
+  reg_errcode_t ret;
+  reg_syntax_t syntax = ((cflags & REG_EXTENDED) ? RE_SYNTAX_POSIX_EXTENDED
+			 : RE_SYNTAX_POSIX_BASIC);
+
+  preg->buffer = NULL;
+  preg->allocated = 0;
+  preg->used = 0;
+
+  /* Try to allocate space for the fastmap.  */
+  preg->fastmap = re_malloc (char, SBC_MAX);
+  if (BE (preg->fastmap == NULL, 0))
+    return REG_ESPACE;
+
+  syntax |= (cflags & REG_ICASE) ? RE_ICASE : 0;
+
+  /* If REG_NEWLINE is set, newlines are treated differently.  */
+  if (cflags & REG_NEWLINE)
+    { /* REG_NEWLINE implies neither . nor [^...] match newline.  */
+      syntax &= ~RE_DOT_NEWLINE;
+      syntax |= RE_HAT_LISTS_NOT_NEWLINE;
+      /* It also changes the matching behavior.  */
+      preg->newline_anchor = 1;
+    }
+  else
+    preg->newline_anchor = 0;
+  preg->no_sub = !!(cflags & REG_NOSUB);
+  preg->translate = NULL;
+
+  ret = re_compile_internal (preg, pattern, strlen (pattern), syntax);
+
+  /* POSIX doesn't distinguish between an unmatched open-group and an
+     unmatched close-group: both are REG_EPAREN.  */
+  if (ret == REG_ERPAREN)
+    ret = REG_EPAREN;
+
+  /* We have already checked preg->fastmap != NULL.  */
+  if (BE (ret == REG_NOERROR, 1))
+    /* Compute the fastmap now, since regexec cannot modify the pattern
+       buffer.  This function never fails in this implementation.  */
+    (void) re_compile_fastmap (preg);
+  else
+    {
+      /* Some error occurred while compiling the expression.  */
+      re_free (preg->fastmap);
+      preg->fastmap = NULL;
+    }
+
+  return (int) ret;
+}
+#ifdef _LIBC
+weak_alias (__regcomp, regcomp)
+#endif
+
+/* Returns a message corresponding to an error code, ERRCODE, returned
+   from either regcomp or regexec.   We don't use PREG here.  */
+
+#ifdef _LIBC
+size_t
+regerror (errcode, preg, errbuf, errbuf_size)
+    int errcode;
+    const regex_t *__restrict preg;
+    char *__restrict errbuf;
+    size_t errbuf_size;
+#else /* size_t might promote */
+size_t
+regerror (int errcode, const regex_t *__restrict preg,
+	  char *__restrict errbuf, size_t errbuf_size)
+#endif
+{
+  const char *msg;
+  size_t msg_size;
+
+  if (BE (errcode < 0
+	  || errcode >= (int) (sizeof (__re_error_msgid_idx)
+			       / sizeof (__re_error_msgid_idx[0])), 0))
+    /* Only error codes returned by the rest of the code should be passed
+       to this routine.  If we are given anything else, or if other regex
+       code generates an invalid error code, then the program has a bug.
+       Dump core so we can fix it.  */
+    abort ();
+
+  msg = gettext (__re_error_msgid + __re_error_msgid_idx[errcode]);
+
+  msg_size = strlen (msg) + 1; /* Includes the null.  */
+
+  if (BE (errbuf_size != 0, 1))
+    {
+      if (BE (msg_size > errbuf_size, 0))
+	{
+#if defined HAVE_MEMPCPY || defined _LIBC
+	  *((char *) __mempcpy (errbuf, msg, errbuf_size - 1)) = '\0';
+#else
+	  memcpy (errbuf, msg, errbuf_size - 1);
+	  errbuf[errbuf_size - 1] = 0;
+#endif
+	}
+      else
+	memcpy (errbuf, msg, msg_size);
+    }
+
+  return msg_size;
+}
+#ifdef _LIBC
+weak_alias (__regerror, regerror)
+#endif
+
+
+#ifdef RE_ENABLE_I18N
+/* This static array is used for the map to single-byte characters when
+   UTF-8 is used.  Otherwise we would allocate memory just to initialize
+   it the same all the time.  UTF-8 is the preferred encoding so this is
+   a worthwhile optimization.  */
+static const bitset_t utf8_sb_map =
+{
+  /* Set the first 128 bits.  */
+# if 4 * BITSET_WORD_BITS < ASCII_CHARS
+#  error "bitset_word_t is narrower than 32 bits"
+# elif 3 * BITSET_WORD_BITS < ASCII_CHARS
+  BITSET_WORD_MAX, BITSET_WORD_MAX, BITSET_WORD_MAX,
+# elif 2 * BITSET_WORD_BITS < ASCII_CHARS
+  BITSET_WORD_MAX, BITSET_WORD_MAX,
+# elif 1 * BITSET_WORD_BITS < ASCII_CHARS
+  BITSET_WORD_MAX,
+# endif
+  (BITSET_WORD_MAX
+   >> (SBC_MAX % BITSET_WORD_BITS == 0
+       ? 0
+       : BITSET_WORD_BITS - SBC_MAX % BITSET_WORD_BITS))
+};
+#endif
+
+
+static void
+free_dfa_content (re_dfa_t *dfa)
+{
+  Idx i, j;
+
+  if (dfa->nodes)
+    for (i = 0; i < dfa->nodes_len; ++i)
+      free_token (dfa->nodes + i);
+  re_free (dfa->nexts);
+  for (i = 0; i < dfa->nodes_len; ++i)
+    {
+      if (dfa->eclosures != NULL)
+	re_node_set_free (dfa->eclosures + i);
+      if (dfa->inveclosures != NULL)
+	re_node_set_free (dfa->inveclosures + i);
+      if (dfa->edests != NULL)
+	re_node_set_free (dfa->edests + i);
+    }
+  re_free (dfa->edests);
+  re_free (dfa->eclosures);
+  re_free (dfa->inveclosures);
+  re_free (dfa->nodes);
+
+  if (dfa->state_table)
+    for (i = 0; i <= dfa->state_hash_mask; ++i)
+      {
+	struct re_state_table_entry *entry = dfa->state_table + i;
+	for (j = 0; j < entry->num; ++j)
+	  {
+	    re_dfastate_t *state = entry->array[j];
+	    free_state (state);
+	  }
+        re_free (entry->array);
+      }
+  re_free (dfa->state_table);
+#ifdef RE_ENABLE_I18N
+  if (dfa->sb_char != utf8_sb_map)
+    re_free (dfa->sb_char);
+#endif
+  re_free (dfa->subexp_map);
+#ifdef DEBUG
+  re_free (dfa->re_str);
+#endif
+
+  re_free (dfa);
+}
+
+
+/* Free dynamically allocated space used by PREG.  */
+
+void
+regfree (preg)
+    regex_t *preg;
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  if (BE (dfa != NULL, 1))
+    free_dfa_content (dfa);
+  preg->buffer = NULL;
+  preg->allocated = 0;
+
+  re_free (preg->fastmap);
+  preg->fastmap = NULL;
+
+  re_free (preg->translate);
+  preg->translate = NULL;
+}
+#ifdef _LIBC
+weak_alias (__regfree, regfree)
+#endif
+
+/* Entry points compatible with 4.2 BSD regex library.  We don't define
+   them unless specifically requested.  */
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+
+/* BSD has one and only one pattern buffer.  */
+static struct re_pattern_buffer re_comp_buf;
+
+char *
+# ifdef _LIBC
+/* Make these definitions weak in libc, so POSIX programs can redefine
+   these names if they don't use our functions, and still use
+   regcomp/regexec above without link errors.  */
+weak_function
+# endif
+re_comp (s)
+     const char *s;
+{
+  reg_errcode_t ret;
+  char *fastmap;
+
+  if (!s)
+    {
+      if (!re_comp_buf.buffer)
+	return gettext ("No previous regular expression");
+      return 0;
+    }
+
+  if (re_comp_buf.buffer)
+    {
+      fastmap = re_comp_buf.fastmap;
+      re_comp_buf.fastmap = NULL;
+      __regfree (&re_comp_buf);
+      memset (&re_comp_buf, '\0', sizeof (re_comp_buf));
+      re_comp_buf.fastmap = fastmap;
+    }
+
+  if (re_comp_buf.fastmap == NULL)
+    {
+      re_comp_buf.fastmap = (char *) malloc (SBC_MAX);
+      if (re_comp_buf.fastmap == NULL)
+	return (char *) gettext (__re_error_msgid
+				 + __re_error_msgid_idx[(int) REG_ESPACE]);
+    }
+
+  /* Since `re_exec' always passes NULL for the `regs' argument, we
+     don't need to initialize the pattern buffer fields which affect it.  */
+
+  /* Match anchors at newlines.  */
+  re_comp_buf.newline_anchor = 1;
+
+  ret = re_compile_internal (&re_comp_buf, s, strlen (s), re_syntax_options);
+
+  if (!ret)
+    return NULL;
+
+  /* Yes, we're discarding `const' here if !HAVE_LIBINTL.  */
+  return (char *) gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
+}
+
+#ifdef _LIBC
+libc_freeres_fn (free_mem)
+{
+  __regfree (&re_comp_buf);
+}
+#endif
+
+#endif /* _REGEX_RE_COMP */
+
+/* Internal entry point.
+   Compile the regular expression PATTERN, whose length is LENGTH.
+   SYNTAX indicate regular expression's syntax.  */
+
+static reg_errcode_t
+re_compile_internal (regex_t *preg, const char * pattern, size_t length,
+		     reg_syntax_t syntax)
+{
+  reg_errcode_t err = REG_NOERROR;
+  re_dfa_t *dfa;
+  re_string_t regexp;
+
+  /* Initialize the pattern buffer.  */
+  preg->fastmap_accurate = 0;
+  preg->syntax = syntax;
+  preg->not_bol = preg->not_eol = 0;
+  preg->used = 0;
+  preg->re_nsub = 0;
+  preg->can_be_null = 0;
+  preg->regs_allocated = REGS_UNALLOCATED;
+
+  /* Initialize the dfa.  */
+  dfa = (re_dfa_t *) preg->buffer;
+  if (BE (preg->allocated < sizeof (re_dfa_t), 0))
+    {
+      /* If zero allocated, but buffer is non-null, try to realloc
+	 enough space.  This loses if buffer's address is bogus, but
+	 that is the user's responsibility.  If ->buffer is NULL this
+	 is a simple allocation.  */
+      dfa = re_realloc (preg->buffer, re_dfa_t, 1);
+      if (dfa == NULL)
+	return REG_ESPACE;
+      preg->allocated = sizeof (re_dfa_t);
+      preg->buffer = (unsigned char *) dfa;
+    }
+  preg->used = sizeof (re_dfa_t);
+
+  err = init_dfa (dfa, length);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+      return err;
+    }
+#ifdef DEBUG
+  /* Note: length+1 will not overflow since it is checked in init_dfa.  */
+  dfa->re_str = re_malloc (char, length + 1);
+  strncpy (dfa->re_str, pattern, length + 1);
+#endif
+
+  __libc_lock_init (dfa->lock);
+
+  err = re_string_construct (&regexp, pattern, length, preg->translate,
+			     syntax & RE_ICASE, dfa);
+  if (BE (err != REG_NOERROR, 0))
+    {
+    re_compile_internal_free_return:
+      free_workarea_compile (preg);
+      re_string_destruct (&regexp);
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+      return err;
+    }
+
+  /* Parse the regular expression, and build a structure tree.  */
+  preg->re_nsub = 0;
+  dfa->str_tree = parse (&regexp, preg, syntax, &err);
+  if (BE (dfa->str_tree == NULL, 0))
+    goto re_compile_internal_free_return;
+
+  /* Analyze the tree and create the nfa.  */
+  err = analyze (preg);
+  if (BE (err != REG_NOERROR, 0))
+    goto re_compile_internal_free_return;
+
+#ifdef RE_ENABLE_I18N
+  /* If possible, do searching in single byte encoding to speed things up.  */
+  if (dfa->is_utf8 && !(syntax & RE_ICASE) && preg->translate == NULL)
+    optimize_utf8 (dfa);
+#endif
+
+  /* Then create the initial state of the dfa.  */
+  err = create_initial_state (dfa);
+
+  /* Release work areas.  */
+  free_workarea_compile (preg);
+  re_string_destruct (&regexp);
+
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+    }
+
+  return err;
+}
+
+/* Initialize DFA.  We use the length of the regular expression PAT_LEN
+   as the initial length of some arrays.  */
+
+static reg_errcode_t
+init_dfa (re_dfa_t *dfa, size_t pat_len)
+{
+  __re_size_t table_size;
+#ifndef _LIBC
+  char *codeset_name;
+#endif
+#ifdef RE_ENABLE_I18N
+  size_t max_i18n_object_size = MAX (sizeof (wchar_t), sizeof (wctype_t));
+#else
+  size_t max_i18n_object_size = 0;
+#endif
+  size_t max_object_size =
+    MAX (sizeof (struct re_state_table_entry),
+	 MAX (sizeof (re_token_t),
+	      MAX (sizeof (re_node_set),
+		   MAX (sizeof (regmatch_t),
+			max_i18n_object_size))));
+
+  memset (dfa, '\0', sizeof (re_dfa_t));
+
+  /* Force allocation of str_tree_storage the first time.  */
+  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
+
+  /* Avoid overflows.  The extra "/ 2" is for the table_size doubling
+     calculation below, and for similar doubling calculations
+     elsewhere.  And it's <= rather than <, because some of the
+     doubling calculations add 1 afterwards.  */
+  if (BE (SIZE_MAX / max_object_size / 2 <= pat_len, 0))
+    return REG_ESPACE;
+
+  dfa->nodes_alloc = pat_len + 1;
+  dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc);
+
+  /*  table_size = 2 ^ ceil(log pat_len) */
+  for (table_size = 1; ; table_size <<= 1)
+    if (table_size > pat_len)
+      break;
+
+  dfa->state_table = calloc (sizeof (struct re_state_table_entry), table_size);
+  dfa->state_hash_mask = table_size - 1;
+
+  dfa->mb_cur_max = MB_CUR_MAX;
+#ifdef _LIBC
+  if (dfa->mb_cur_max == 6
+      && strcmp (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_CODESET_NAME), "UTF-8") == 0)
+    dfa->is_utf8 = 1;
+  dfa->map_notascii = (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MAP_TO_NONASCII)
+		       != 0);
+#else
+# ifdef HAVE_LANGINFO_CODESET
+  codeset_name = nl_langinfo (CODESET);
+# else
+  codeset_name = getenv ("LC_ALL");
+  if (codeset_name == NULL || codeset_name[0] == '\0')
+    codeset_name = getenv ("LC_CTYPE");
+  if (codeset_name == NULL || codeset_name[0] == '\0')
+    codeset_name = getenv ("LANG");
+  if (codeset_name == NULL)
+    codeset_name = "";
+  else if (strchr (codeset_name, '.') !=  NULL)
+    codeset_name = strchr (codeset_name, '.') + 1;
+# endif
+
+  if (strcasecmp (codeset_name, "UTF-8") == 0
+      || strcasecmp (codeset_name, "UTF8") == 0)
+    dfa->is_utf8 = 1;
+
+  /* We check exhaustively in the loop below if this charset is a
+     superset of ASCII.  */
+  dfa->map_notascii = 0;
+#endif
+
+#ifdef RE_ENABLE_I18N
+  if (dfa->mb_cur_max > 1)
+    {
+      if (dfa->is_utf8)
+	dfa->sb_char = (re_bitset_ptr_t) utf8_sb_map;
+      else
+	{
+	  int i, j, ch;
+
+	  dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+	  if (BE (dfa->sb_char == NULL, 0))
+	    return REG_ESPACE;
+
+	  /* Set the bits corresponding to single byte chars.  */
+	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+	    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+	      {
+		wint_t wch = __btowc (ch);
+		if (wch != WEOF)
+		  dfa->sb_char[i] |= (bitset_word_t) 1 << j;
+# ifndef _LIBC
+		if (isascii (ch) && wch != ch)
+		  dfa->map_notascii = 1;
+# endif
+	      }
+	}
+    }
+#endif
+
+  if (BE (dfa->nodes == NULL || dfa->state_table == NULL, 0))
+    return REG_ESPACE;
+  return REG_NOERROR;
+}
+
+/* Initialize WORD_CHAR table, which indicate which character is
+   "word".  In this case "word" means that it is the word construction
+   character used by some operators like "\<", "\>", etc.  */
+
+static void
+internal_function
+init_word_char (re_dfa_t *dfa)
+{
+  int i, j, ch;
+  dfa->word_ops_used = 1;
+  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+      if (isalnum (ch) || ch == '_')
+	dfa->word_char[i] |= (bitset_word_t) 1 << j;
+}
+
+/* Free the work area which are only used while compiling.  */
+
+static void
+free_workarea_compile (regex_t *preg)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_storage_t *storage, *next;
+  for (storage = dfa->str_tree_storage; storage; storage = next)
+    {
+      next = storage->next;
+      re_free (storage);
+    }
+  dfa->str_tree_storage = NULL;
+  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
+  dfa->str_tree = NULL;
+  re_free (dfa->org_indices);
+  dfa->org_indices = NULL;
+}
+
+/* Create initial states for all contexts.  */
+
+static reg_errcode_t
+create_initial_state (re_dfa_t *dfa)
+{
+  Idx first, i;
+  reg_errcode_t err;
+  re_node_set init_nodes;
+
+  /* Initial states have the epsilon closure of the node which is
+     the first node of the regular expression.  */
+  first = dfa->str_tree->first->node_idx;
+  dfa->init_node = first;
+  err = re_node_set_init_copy (&init_nodes, dfa->eclosures + first);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  /* The back-references which are in initial states can epsilon transit,
+     since in this case all of the subexpressions can be null.
+     Then we add epsilon closures of the nodes which are the next nodes of
+     the back-references.  */
+  if (dfa->nbackref > 0)
+    for (i = 0; i < init_nodes.nelem; ++i)
+      {
+	Idx node_idx = init_nodes.elems[i];
+	re_token_type_t type = dfa->nodes[node_idx].type;
+
+	Idx clexp_idx;
+	if (type != OP_BACK_REF)
+	  continue;
+	for (clexp_idx = 0; clexp_idx < init_nodes.nelem; ++clexp_idx)
+	  {
+	    re_token_t *clexp_node;
+	    clexp_node = dfa->nodes + init_nodes.elems[clexp_idx];
+	    if (clexp_node->type == OP_CLOSE_SUBEXP
+		&& clexp_node->opr.idx == dfa->nodes[node_idx].opr.idx)
+	      break;
+	  }
+	if (clexp_idx == init_nodes.nelem)
+	  continue;
+
+	if (type == OP_BACK_REF)
+	  {
+	    Idx dest_idx = dfa->edests[node_idx].elems[0];
+	    if (!re_node_set_contains (&init_nodes, dest_idx))
+	      {
+		re_node_set_merge (&init_nodes, dfa->eclosures + dest_idx);
+		i = 0;
+	      }
+	  }
+      }
+
+  /* It must be the first time to invoke acquire_state.  */
+  dfa->init_state = re_acquire_state_context (&err, dfa, &init_nodes, 0);
+  /* We don't check ERR here, since the initial state must not be NULL.  */
+  if (BE (dfa->init_state == NULL, 0))
+    return err;
+  if (dfa->init_state->has_constraint)
+    {
+      dfa->init_state_word = re_acquire_state_context (&err, dfa, &init_nodes,
+						       CONTEXT_WORD);
+      dfa->init_state_nl = re_acquire_state_context (&err, dfa, &init_nodes,
+						     CONTEXT_NEWLINE);
+      dfa->init_state_begbuf = re_acquire_state_context (&err, dfa,
+							 &init_nodes,
+							 CONTEXT_NEWLINE
+							 | CONTEXT_BEGBUF);
+      if (BE (dfa->init_state_word == NULL || dfa->init_state_nl == NULL
+	      || dfa->init_state_begbuf == NULL, 0))
+	return err;
+    }
+  else
+    dfa->init_state_word = dfa->init_state_nl
+      = dfa->init_state_begbuf = dfa->init_state;
+
+  re_node_set_free (&init_nodes);
+  return REG_NOERROR;
+}
+
+#ifdef RE_ENABLE_I18N
+/* If it is possible to do searching in single byte encoding instead of UTF-8
+   to speed things up, set dfa->mb_cur_max to 1, clear is_utf8 and change
+   DFA nodes where needed.  */
+
+static void
+optimize_utf8 (re_dfa_t *dfa)
+{
+  Idx node;
+  int i;
+  bool mb_chars = false;
+  bool has_period = false;
+
+  for (node = 0; node < dfa->nodes_len; ++node)
+    switch (dfa->nodes[node].type)
+      {
+      case CHARACTER:
+	if (dfa->nodes[node].opr.c >= ASCII_CHARS)
+	  mb_chars = true;
+	break;
+      case ANCHOR:
+	switch (dfa->nodes[node].opr.idx)
+	  {
+	  case LINE_FIRST:
+	  case LINE_LAST:
+	  case BUF_FIRST:
+	  case BUF_LAST:
+	    break;
+	  default:
+	    /* Word anchors etc. cannot be handled.  */
+	    return;
+	  }
+	break;
+      case OP_PERIOD:
+        has_period = true;
+        break;
+      case OP_BACK_REF:
+      case OP_ALT:
+      case END_OF_RE:
+      case OP_DUP_ASTERISK:
+      case OP_OPEN_SUBEXP:
+      case OP_CLOSE_SUBEXP:
+	break;
+      case COMPLEX_BRACKET:
+	return;
+      case SIMPLE_BRACKET:
+	/* Just double check.  */
+	{
+	  int rshift = (ASCII_CHARS % BITSET_WORD_BITS == 0
+			? 0
+			: BITSET_WORD_BITS - ASCII_CHARS % BITSET_WORD_BITS);
+	  for (i = ASCII_CHARS / BITSET_WORD_BITS; i < BITSET_WORDS; ++i)
+	    {
+	      if (dfa->nodes[node].opr.sbcset[i] >> rshift != 0)
+		return;
+	      rshift = 0;
+	    }
+	}
+	break;
+      default:
+	abort ();
+      }
+
+  if (mb_chars || has_period)
+    for (node = 0; node < dfa->nodes_len; ++node)
+      {
+	if (dfa->nodes[node].type == CHARACTER
+	    && dfa->nodes[node].opr.c >= ASCII_CHARS)
+	  dfa->nodes[node].mb_partial = 0;
+	else if (dfa->nodes[node].type == OP_PERIOD)
+	  dfa->nodes[node].type = OP_UTF8_PERIOD;
+      }
+
+  /* The search can be in single byte locale.  */
+  dfa->mb_cur_max = 1;
+  dfa->is_utf8 = 0;
+  dfa->has_mb_node = dfa->nbackref > 0 || has_period;
+}
+#endif
+
+/* Analyze the structure tree, and calculate "first", "next", "edest",
+   "eclosure", and "inveclosure".  */
+
+static reg_errcode_t
+analyze (regex_t *preg)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  reg_errcode_t ret;
+
+  /* Allocate arrays.  */
+  dfa->nexts = re_malloc (Idx, dfa->nodes_alloc);
+  dfa->org_indices = re_malloc (Idx, dfa->nodes_alloc);
+  dfa->edests = re_malloc (re_node_set, dfa->nodes_alloc);
+  dfa->eclosures = re_malloc (re_node_set, dfa->nodes_alloc);
+  if (BE (dfa->nexts == NULL || dfa->org_indices == NULL || dfa->edests == NULL
+	  || dfa->eclosures == NULL, 0))
+    return REG_ESPACE;
+
+  dfa->subexp_map = re_malloc (Idx, preg->re_nsub);
+  if (dfa->subexp_map != NULL)
+    {
+      Idx i;
+      for (i = 0; i < preg->re_nsub; i++)
+	dfa->subexp_map[i] = i;
+      preorder (dfa->str_tree, optimize_subexps, dfa);
+      for (i = 0; i < preg->re_nsub; i++)
+	if (dfa->subexp_map[i] != i)
+	  break;
+      if (i == preg->re_nsub)
+	{
+	  free (dfa->subexp_map);
+	  dfa->subexp_map = NULL;
+	}
+    }
+
+  ret = postorder (dfa->str_tree, lower_subexps, preg);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  ret = postorder (dfa->str_tree, calc_first, dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  preorder (dfa->str_tree, calc_next, dfa);
+  ret = preorder (dfa->str_tree, link_nfa_nodes, dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  ret = calc_eclosure (dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  /* We only need this during the prune_impossible_nodes pass in regexec.c;
+     skip it if p_i_n will not run, as calc_inveclosure can be quadratic.  */
+  if ((!preg->no_sub && preg->re_nsub > 0 && dfa->has_plural_match)
+      || dfa->nbackref)
+    {
+      dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_len);
+      if (BE (dfa->inveclosures == NULL, 0))
+        return REG_ESPACE;
+      ret = calc_inveclosure (dfa);
+    }
+
+  return ret;
+}
+
+/* Our parse trees are very unbalanced, so we cannot use a stack to
+   implement parse tree visits.  Instead, we use parent pointers and
+   some hairy code in these two functions.  */
+static reg_errcode_t
+postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
+	   void *extra)
+{
+  bin_tree_t *node, *prev;
+
+  for (node = root; ; )
+    {
+      /* Descend down the tree, preferably to the left (or to the right
+	 if that's the only child).  */
+      while (node->left || node->right)
+	if (node->left)
+          node = node->left;
+        else
+          node = node->right;
+
+      do
+	{
+	  reg_errcode_t err = fn (extra, node);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+          if (node->parent == NULL)
+	    return REG_NOERROR;
+	  prev = node;
+	  node = node->parent;
+	}
+      /* Go up while we have a node that is reached from the right.  */
+      while (node->right == prev || node->right == NULL);
+      node = node->right;
+    }
+}
+
+static reg_errcode_t
+preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
+	  void *extra)
+{
+  bin_tree_t *node;
+
+  for (node = root; ; )
+    {
+      reg_errcode_t err = fn (extra, node);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+
+      /* Go to the left node, or up and to the right.  */
+      if (node->left)
+	node = node->left;
+      else
+	{
+	  bin_tree_t *prev = NULL;
+	  while (node->right == prev || node->right == NULL)
+	    {
+	      prev = node;
+	      node = node->parent;
+	      if (!node)
+	        return REG_NOERROR;
+	    }
+	  node = node->right;
+	}
+    }
+}
+
+/* Optimization pass: if a SUBEXP is entirely contained, strip it and tell
+   re_search_internal to map the inner one's opr.idx to this one's.  Adjust
+   backreferences as well.  Requires a preorder visit.  */
+static reg_errcode_t
+optimize_subexps (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+
+  if (node->token.type == OP_BACK_REF && dfa->subexp_map)
+    {
+      int idx = node->token.opr.idx;
+      node->token.opr.idx = dfa->subexp_map[idx];
+      dfa->used_bkref_map |= 1 << node->token.opr.idx;
+    }
+
+  else if (node->token.type == SUBEXP
+           && node->left && node->left->token.type == SUBEXP)
+    {
+      Idx other_idx = node->left->token.opr.idx;
+
+      node->left = node->left->left;
+      if (node->left)
+        node->left->parent = node;
+
+      dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx];
+      if (other_idx < BITSET_WORD_BITS)
+	dfa->used_bkref_map &= ~((bitset_word_t) 1 << other_idx);
+    }
+
+  return REG_NOERROR;
+}
+
+/* Lowering pass: Turn each SUBEXP node into the appropriate concatenation
+   of OP_OPEN_SUBEXP, the body of the SUBEXP (if any) and OP_CLOSE_SUBEXP.  */
+static reg_errcode_t
+lower_subexps (void *extra, bin_tree_t *node)
+{
+  regex_t *preg = (regex_t *) extra;
+  reg_errcode_t err = REG_NOERROR;
+
+  if (node->left && node->left->token.type == SUBEXP)
+    {
+      node->left = lower_subexp (&err, preg, node->left);
+      if (node->left)
+	node->left->parent = node;
+    }
+  if (node->right && node->right->token.type == SUBEXP)
+    {
+      node->right = lower_subexp (&err, preg, node->right);
+      if (node->right)
+	node->right->parent = node;
+    }
+
+  return err;
+}
+
+static bin_tree_t *
+lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *body = node->left;
+  bin_tree_t *op, *cls, *tree1, *tree;
+
+  if (preg->no_sub
+      /* We do not optimize empty subexpressions, because otherwise we may
+	 have bad CONCAT nodes with NULL children.  This is obviously not
+	 very common, so we do not lose much.  An example that triggers
+	 this case is the sed "script" /\(\)/x.  */
+      && node->left != NULL
+      && (node->token.opr.idx >= BITSET_WORD_BITS
+	  || !(dfa->used_bkref_map
+	       & ((bitset_word_t) 1 << node->token.opr.idx))))
+    return node->left;
+
+  /* Convert the SUBEXP node to the concatenation of an
+     OP_OPEN_SUBEXP, the contents, and an OP_CLOSE_SUBEXP.  */
+  op = create_tree (dfa, NULL, NULL, OP_OPEN_SUBEXP);
+  cls = create_tree (dfa, NULL, NULL, OP_CLOSE_SUBEXP);
+  tree1 = body ? create_tree (dfa, body, cls, CONCAT) : cls;
+  tree = create_tree (dfa, op, tree1, CONCAT);
+  if (BE (tree == NULL || tree1 == NULL || op == NULL || cls == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  op->token.opr.idx = cls->token.opr.idx = node->token.opr.idx;
+  op->token.opt_subexp = cls->token.opt_subexp = node->token.opt_subexp;
+  return tree;
+}
+
+/* Pass 1 in building the NFA: compute FIRST and create unlinked automaton
+   nodes.  Requires a postorder visit.  */
+static reg_errcode_t
+calc_first (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+  if (node->token.type == CONCAT)
+    {
+      node->first = node->left->first;
+      node->node_idx = node->left->node_idx;
+    }
+  else
+    {
+      node->first = node;
+      node->node_idx = re_dfa_add_node (dfa, node->token);
+      if (BE (node->node_idx == REG_MISSING, 0))
+        return REG_ESPACE;
+    }
+  return REG_NOERROR;
+}
+
+/* Pass 2: compute NEXT on the tree.  Preorder visit.  */
+static reg_errcode_t
+calc_next (void *extra, bin_tree_t *node)
+{
+  switch (node->token.type)
+    {
+    case OP_DUP_ASTERISK:
+      node->left->next = node;
+      break;
+    case CONCAT:
+      node->left->next = node->right->first;
+      node->right->next = node->next;
+      break;
+    default:
+      if (node->left)
+	node->left->next = node->next;
+      if (node->right)
+        node->right->next = node->next;
+      break;
+    }
+  return REG_NOERROR;
+}
+
+/* Pass 3: link all DFA nodes to their NEXT node (any order will do).  */
+static reg_errcode_t
+link_nfa_nodes (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+  Idx idx = node->node_idx;
+  reg_errcode_t err = REG_NOERROR;
+
+  switch (node->token.type)
+    {
+    case CONCAT:
+      break;
+
+    case END_OF_RE:
+      assert (node->next == NULL);
+      break;
+
+    case OP_DUP_ASTERISK:
+    case OP_ALT:
+      {
+	Idx left, right;
+	dfa->has_plural_match = 1;
+	if (node->left != NULL)
+	  left = node->left->first->node_idx;
+	else
+	  left = node->next->node_idx;
+	if (node->right != NULL)
+	  right = node->right->first->node_idx;
+	else
+	  right = node->next->node_idx;
+	assert (REG_VALID_INDEX (left));
+	assert (REG_VALID_INDEX (right));
+	err = re_node_set_init_2 (dfa->edests + idx, left, right);
+      }
+      break;
+
+    case ANCHOR:
+    case OP_OPEN_SUBEXP:
+    case OP_CLOSE_SUBEXP:
+      err = re_node_set_init_1 (dfa->edests + idx, node->next->node_idx);
+      break;
+
+    case OP_BACK_REF:
+      dfa->nexts[idx] = node->next->node_idx;
+      if (node->token.type == OP_BACK_REF)
+	re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
+      break;
+
+    default:
+      assert (!IS_EPSILON_NODE (node->token.type));
+      dfa->nexts[idx] = node->next->node_idx;
+      break;
+    }
+
+  return err;
+}
+
+/* Duplicate the epsilon closure of the node ROOT_NODE.
+   Note that duplicated nodes have constraint INIT_CONSTRAINT in addition
+   to their own constraint.  */
+
+static reg_errcode_t
+internal_function
+duplicate_node_closure (re_dfa_t *dfa, Idx top_org_node, Idx top_clone_node,
+			Idx root_node, unsigned int init_constraint)
+{
+  Idx org_node, clone_node;
+  bool ok;
+  unsigned int constraint = init_constraint;
+  for (org_node = top_org_node, clone_node = top_clone_node;;)
+    {
+      Idx org_dest, clone_dest;
+      if (dfa->nodes[org_node].type == OP_BACK_REF)
+	{
+	  /* If the back reference epsilon-transit, its destination must
+	     also have the constraint.  Then duplicate the epsilon closure
+	     of the destination of the back reference, and store it in
+	     edests of the back reference.  */
+	  org_dest = dfa->nexts[org_node];
+	  re_node_set_empty (dfa->edests + clone_node);
+	  clone_dest = duplicate_node (dfa, org_dest, constraint);
+	  if (BE (clone_dest == REG_MISSING, 0))
+	    return REG_ESPACE;
+	  dfa->nexts[clone_node] = dfa->nexts[org_node];
+	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	  if (BE (! ok, 0))
+	    return REG_ESPACE;
+	}
+      else if (dfa->edests[org_node].nelem == 0)
+	{
+	  /* In case of the node can't epsilon-transit, don't duplicate the
+	     destination and store the original destination as the
+	     destination of the node.  */
+	  dfa->nexts[clone_node] = dfa->nexts[org_node];
+	  break;
+	}
+      else if (dfa->edests[org_node].nelem == 1)
+	{
+	  /* In case of the node can epsilon-transit, and it has only one
+	     destination.  */
+	  org_dest = dfa->edests[org_node].elems[0];
+	  re_node_set_empty (dfa->edests + clone_node);
+	  if (dfa->nodes[org_node].type == ANCHOR)
+	    {
+	      /* In case of the node has another constraint, append it.  */
+	      if (org_node == root_node && clone_node != org_node)
+		{
+		  /* ...but if the node is root_node itself, it means the
+		     epsilon closure have a loop, then tie it to the
+		     destination of the root_node.  */
+		  ok = re_node_set_insert (dfa->edests + clone_node, org_dest);
+		  if (BE (! ok, 0))
+		    return REG_ESPACE;
+		  break;
+		}
+	      constraint |= dfa->nodes[org_node].opr.ctx_type;
+	    }
+	  clone_dest = duplicate_node (dfa, org_dest, constraint);
+	  if (BE (clone_dest == REG_MISSING, 0))
+	    return REG_ESPACE;
+	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	  if (BE (! ok, 0))
+	    return REG_ESPACE;
+	}
+      else /* dfa->edests[org_node].nelem == 2 */
+	{
+	  /* In case of the node can epsilon-transit, and it has two
+	     destinations. In the bin_tree_t and DFA, that's '|' and '*'.   */
+	  org_dest = dfa->edests[org_node].elems[0];
+	  re_node_set_empty (dfa->edests + clone_node);
+	  /* Search for a duplicated node which satisfies the constraint.  */
+	  clone_dest = search_duplicated_node (dfa, org_dest, constraint);
+	  if (clone_dest == REG_MISSING)
+	    {
+	      /* There are no such a duplicated node, create a new one.  */
+	      reg_errcode_t err;
+	      clone_dest = duplicate_node (dfa, org_dest, constraint);
+	      if (BE (clone_dest == REG_MISSING, 0))
+		return REG_ESPACE;
+	      ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	      if (BE (! ok, 0))
+		return REG_ESPACE;
+	      err = duplicate_node_closure (dfa, org_dest, clone_dest,
+					    root_node, constraint);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+	  else
+	    {
+	      /* There are a duplicated node which satisfy the constraint,
+		 use it to avoid infinite loop.  */
+	      ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	      if (BE (! ok, 0))
+		return REG_ESPACE;
+	    }
+
+	  org_dest = dfa->edests[org_node].elems[1];
+	  clone_dest = duplicate_node (dfa, org_dest, constraint);
+	  if (BE (clone_dest == REG_MISSING, 0))
+	    return REG_ESPACE;
+	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	  if (BE (! ok, 0))
+	    return REG_ESPACE;
+	}
+      org_node = org_dest;
+      clone_node = clone_dest;
+    }
+  return REG_NOERROR;
+}
+
+/* Search for a node which is duplicated from the node ORG_NODE, and
+   satisfies the constraint CONSTRAINT.  */
+
+static Idx
+search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
+			unsigned int constraint)
+{
+  Idx idx;
+  for (idx = dfa->nodes_len - 1; dfa->nodes[idx].duplicated && idx > 0; --idx)
+    {
+      if (org_node == dfa->org_indices[idx]
+	  && constraint == dfa->nodes[idx].constraint)
+	return idx; /* Found.  */
+    }
+  return REG_MISSING; /* Not found.  */
+}
+
+/* Duplicate the node whose index is ORG_IDX and set the constraint CONSTRAINT.
+   Return the index of the new node, or REG_MISSING if insufficient storage is
+   available.  */
+
+static Idx
+duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int constraint)
+{
+  Idx dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx]);
+  if (BE (dup_idx != REG_MISSING, 1))
+    {
+      dfa->nodes[dup_idx].constraint = constraint;
+      if (dfa->nodes[org_idx].type == ANCHOR)
+	dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].opr.ctx_type;
+      dfa->nodes[dup_idx].duplicated = 1;
+
+      /* Store the index of the original node.  */
+      dfa->org_indices[dup_idx] = org_idx;
+    }
+  return dup_idx;
+}
+
+static reg_errcode_t
+calc_inveclosure (re_dfa_t *dfa)
+{
+  Idx src, idx;
+  bool ok;
+  for (idx = 0; idx < dfa->nodes_len; ++idx)
+    re_node_set_init_empty (dfa->inveclosures + idx);
+
+  for (src = 0; src < dfa->nodes_len; ++src)
+    {
+      Idx *elems = dfa->eclosures[src].elems;
+      for (idx = 0; idx < dfa->eclosures[src].nelem; ++idx)
+	{
+	  ok = re_node_set_insert_last (dfa->inveclosures + elems[idx], src);
+	  if (BE (! ok, 0))
+	    return REG_ESPACE;
+	}
+    }
+
+  return REG_NOERROR;
+}
+
+/* Calculate "eclosure" for all the node in DFA.  */
+
+static reg_errcode_t
+calc_eclosure (re_dfa_t *dfa)
+{
+  Idx node_idx;
+  bool incomplete;
+#ifdef DEBUG
+  assert (dfa->nodes_len > 0);
+#endif
+  incomplete = false;
+  /* For each nodes, calculate epsilon closure.  */
+  for (node_idx = 0; ; ++node_idx)
+    {
+      reg_errcode_t err;
+      re_node_set eclosure_elem;
+      if (node_idx == dfa->nodes_len)
+	{
+	  if (!incomplete)
+	    break;
+	  incomplete = false;
+	  node_idx = 0;
+	}
+
+#ifdef DEBUG
+      assert (dfa->eclosures[node_idx].nelem != REG_MISSING);
+#endif
+
+      /* If we have already calculated, skip it.  */
+      if (dfa->eclosures[node_idx].nelem != 0)
+	continue;
+      /* Calculate epsilon closure of `node_idx'.  */
+      err = calc_eclosure_iter (&eclosure_elem, dfa, node_idx, true);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+
+      if (dfa->eclosures[node_idx].nelem == 0)
+	{
+	  incomplete = true;
+	  re_node_set_free (&eclosure_elem);
+	}
+    }
+  return REG_NOERROR;
+}
+
+/* Calculate epsilon closure of NODE.  */
+
+static reg_errcode_t
+calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root)
+{
+  reg_errcode_t err;
+  unsigned int constraint;
+  Idx i;
+  bool incomplete;
+  bool ok;
+  re_node_set eclosure;
+  incomplete = false;
+  err = re_node_set_alloc (&eclosure, dfa->edests[node].nelem + 1);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  /* This indicates that we are calculating this node now.
+     We reference this value to avoid infinite loop.  */
+  dfa->eclosures[node].nelem = REG_MISSING;
+
+  constraint = ((dfa->nodes[node].type == ANCHOR)
+		? dfa->nodes[node].opr.ctx_type : 0);
+  /* If the current node has constraints, duplicate all nodes.
+     Since they must inherit the constraints.  */
+  if (constraint
+      && dfa->edests[node].nelem
+      && !dfa->nodes[dfa->edests[node].elems[0]].duplicated)
+    {
+      err = duplicate_node_closure (dfa, node, node, node, constraint);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+
+  /* Expand each epsilon destination nodes.  */
+  if (IS_EPSILON_NODE(dfa->nodes[node].type))
+    for (i = 0; i < dfa->edests[node].nelem; ++i)
+      {
+	re_node_set eclosure_elem;
+	Idx edest = dfa->edests[node].elems[i];
+	/* If calculating the epsilon closure of `edest' is in progress,
+	   return intermediate result.  */
+	if (dfa->eclosures[edest].nelem == REG_MISSING)
+	  {
+	    incomplete = true;
+	    continue;
+	  }
+	/* If we haven't calculated the epsilon closure of `edest' yet,
+	   calculate now. Otherwise use calculated epsilon closure.  */
+	if (dfa->eclosures[edest].nelem == 0)
+	  {
+	    err = calc_eclosure_iter (&eclosure_elem, dfa, edest, false);
+	    if (BE (err != REG_NOERROR, 0))
+	      return err;
+	  }
+	else
+	  eclosure_elem = dfa->eclosures[edest];
+	/* Merge the epsilon closure of `edest'.  */
+	re_node_set_merge (&eclosure, &eclosure_elem);
+	/* If the epsilon closure of `edest' is incomplete,
+	   the epsilon closure of this node is also incomplete.  */
+	if (dfa->eclosures[edest].nelem == 0)
+	  {
+	    incomplete = true;
+	    re_node_set_free (&eclosure_elem);
+	  }
+      }
+
+  /* Epsilon closures include itself.  */
+  ok = re_node_set_insert (&eclosure, node);
+  if (BE (! ok, 0))
+    return REG_ESPACE;
+  if (incomplete && !root)
+    dfa->eclosures[node].nelem = 0;
+  else
+    dfa->eclosures[node] = eclosure;
+  *new_set = eclosure;
+  return REG_NOERROR;
+}
+
+/* Functions for token which are used in the parser.  */
+
+/* Fetch a token from INPUT.
+   We must not use this function inside bracket expressions.  */
+
+static void
+internal_function
+fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax)
+{
+  re_string_skip_bytes (input, peek_token (result, input, syntax));
+}
+
+/* Peek a token from INPUT, and return the length of the token.
+   We must not use this function inside bracket expressions.  */
+
+static int
+internal_function
+peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+{
+  unsigned char c;
+
+  if (re_string_eoi (input))
+    {
+      token->type = END_OF_RE;
+      return 0;
+    }
+
+  c = re_string_peek_byte (input, 0);
+  token->opr.c = c;
+
+  token->word_char = 0;
+#ifdef RE_ENABLE_I18N
+  token->mb_partial = 0;
+  if (input->mb_cur_max > 1 &&
+      !re_string_first_byte (input, re_string_cur_idx (input)))
+    {
+      token->type = CHARACTER;
+      token->mb_partial = 1;
+      return 1;
+    }
+#endif
+  if (c == '\\')
+    {
+      unsigned char c2;
+      if (re_string_cur_idx (input) + 1 >= re_string_length (input))
+	{
+	  token->type = BACK_SLASH;
+	  return 1;
+	}
+
+      c2 = re_string_peek_byte_case (input, 1);
+      token->opr.c = c2;
+      token->type = CHARACTER;
+#ifdef RE_ENABLE_I18N
+      if (input->mb_cur_max > 1)
+	{
+	  wint_t wc = re_string_wchar_at (input,
+					  re_string_cur_idx (input) + 1);
+	  token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
+	}
+      else
+#endif
+	token->word_char = IS_WORD_CHAR (c2) != 0;
+
+      switch (c2)
+	{
+	case '|':
+	  if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_NO_BK_VBAR))
+	    token->type = OP_ALT;
+	  break;
+	case '1': case '2': case '3': case '4': case '5':
+	case '6': case '7': case '8': case '9':
+	  if (!(syntax & RE_NO_BK_REFS))
+	    {
+	      token->type = OP_BACK_REF;
+	      token->opr.idx = c2 - '1';
+	    }
+	  break;
+	case '<':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = WORD_FIRST;
+	    }
+	  break;
+	case '>':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = WORD_LAST;
+	    }
+	  break;
+	case 'b':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = WORD_DELIM;
+	    }
+	  break;
+	case 'B':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = NOT_WORD_DELIM;
+	    }
+	  break;
+	case 'w':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_WORD;
+	  break;
+	case 'W':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_NOTWORD;
+	  break;
+	case 's':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_SPACE;
+	  break;
+	case 'S':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_NOTSPACE;
+	  break;
+	case '`':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = BUF_FIRST;
+	    }
+	  break;
+	case '\'':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = BUF_LAST;
+	    }
+	  break;
+	case '(':
+	  if (!(syntax & RE_NO_BK_PARENS))
+	    token->type = OP_OPEN_SUBEXP;
+	  break;
+	case ')':
+	  if (!(syntax & RE_NO_BK_PARENS))
+	    token->type = OP_CLOSE_SUBEXP;
+	  break;
+	case '+':
+	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
+	    token->type = OP_DUP_PLUS;
+	  break;
+	case '?':
+	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
+	    token->type = OP_DUP_QUESTION;
+	  break;
+	case '{':
+	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
+	    token->type = OP_OPEN_DUP_NUM;
+	  break;
+	case '}':
+	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
+	    token->type = OP_CLOSE_DUP_NUM;
+	  break;
+	default:
+	  break;
+	}
+      return 2;
+    }
+
+  token->type = CHARACTER;
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1)
+    {
+      wint_t wc = re_string_wchar_at (input, re_string_cur_idx (input));
+      token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
+    }
+  else
+#endif
+    token->word_char = IS_WORD_CHAR (token->opr.c);
+
+  switch (c)
+    {
+    case '\n':
+      if (syntax & RE_NEWLINE_ALT)
+	token->type = OP_ALT;
+      break;
+    case '|':
+      if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_NO_BK_VBAR))
+	token->type = OP_ALT;
+      break;
+    case '*':
+      token->type = OP_DUP_ASTERISK;
+      break;
+    case '+':
+      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
+	token->type = OP_DUP_PLUS;
+      break;
+    case '?':
+      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
+	token->type = OP_DUP_QUESTION;
+      break;
+    case '{':
+      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
+	token->type = OP_OPEN_DUP_NUM;
+      break;
+    case '}':
+      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
+	token->type = OP_CLOSE_DUP_NUM;
+      break;
+    case '(':
+      if (syntax & RE_NO_BK_PARENS)
+	token->type = OP_OPEN_SUBEXP;
+      break;
+    case ')':
+      if (syntax & RE_NO_BK_PARENS)
+	token->type = OP_CLOSE_SUBEXP;
+      break;
+    case '[':
+      token->type = OP_OPEN_BRACKET;
+      break;
+    case '.':
+      token->type = OP_PERIOD;
+      break;
+    case '^':
+      if (!(syntax & (RE_CONTEXT_INDEP_ANCHORS | RE_CARET_ANCHORS_HERE)) &&
+	  re_string_cur_idx (input) != 0)
+	{
+	  char prev = re_string_peek_byte (input, -1);
+	  if (!(syntax & RE_NEWLINE_ALT) || prev != '\n')
+	    break;
+	}
+      token->type = ANCHOR;
+      token->opr.ctx_type = LINE_FIRST;
+      break;
+    case '$':
+      if (!(syntax & RE_CONTEXT_INDEP_ANCHORS) &&
+	  re_string_cur_idx (input) + 1 != re_string_length (input))
+	{
+	  re_token_t next;
+	  re_string_skip_bytes (input, 1);
+	  peek_token (&next, input, syntax);
+	  re_string_skip_bytes (input, -1);
+	  if (next.type != OP_ALT && next.type != OP_CLOSE_SUBEXP)
+	    break;
+	}
+      token->type = ANCHOR;
+      token->opr.ctx_type = LINE_LAST;
+      break;
+    default:
+      break;
+    }
+  return 1;
+}
+
+/* Peek a token from INPUT, and return the length of the token.
+   We must not use this function out of bracket expressions.  */
+
+static int
+internal_function
+peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+{
+  unsigned char c;
+  if (re_string_eoi (input))
+    {
+      token->type = END_OF_RE;
+      return 0;
+    }
+  c = re_string_peek_byte (input, 0);
+  token->opr.c = c;
+
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1 &&
+      !re_string_first_byte (input, re_string_cur_idx (input)))
+    {
+      token->type = CHARACTER;
+      return 1;
+    }
+#endif /* RE_ENABLE_I18N */
+
+  if (c == '\\' && (syntax & RE_BACKSLASH_ESCAPE_IN_LISTS)
+      && re_string_cur_idx (input) + 1 < re_string_length (input))
+    {
+      /* In this case, '\' escape a character.  */
+      unsigned char c2;
+      re_string_skip_bytes (input, 1);
+      c2 = re_string_peek_byte (input, 0);
+      token->opr.c = c2;
+      token->type = CHARACTER;
+      return 1;
+    }
+  if (c == '[') /* '[' is a special char in a bracket exps.  */
+    {
+      unsigned char c2;
+      int token_len;
+      if (re_string_cur_idx (input) + 1 < re_string_length (input))
+	c2 = re_string_peek_byte (input, 1);
+      else
+	c2 = 0;
+      token->opr.c = c2;
+      token_len = 2;
+      switch (c2)
+	{
+	case '.':
+	  token->type = OP_OPEN_COLL_ELEM;
+	  break;
+	case '=':
+	  token->type = OP_OPEN_EQUIV_CLASS;
+	  break;
+	case ':':
+	  if (syntax & RE_CHAR_CLASSES)
+	    {
+	      token->type = OP_OPEN_CHAR_CLASS;
+	      break;
+	    }
+	  /* else fall through.  */
+	default:
+	  token->type = CHARACTER;
+	  token->opr.c = c;
+	  token_len = 1;
+	  break;
+	}
+      return token_len;
+    }
+  switch (c)
+    {
+    case '-':
+      token->type = OP_CHARSET_RANGE;
+      break;
+    case ']':
+      token->type = OP_CLOSE_BRACKET;
+      break;
+    case '^':
+      token->type = OP_NON_MATCH_LIST;
+      break;
+    default:
+      token->type = CHARACTER;
+    }
+  return 1;
+}
+
+/* Functions for parser.  */
+
+/* Entry point of the parser.
+   Parse the regular expression REGEXP and return the structure tree.
+   If an error is occured, ERR is set by error code, and return NULL.
+   This function build the following tree, from regular expression <reg_exp>:
+	   CAT
+	   / \
+	  /   \
+   <reg_exp>  EOR
+
+   CAT means concatenation.
+   EOR means end of regular expression.  */
+
+static bin_tree_t *
+parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
+       reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree, *eor, *root;
+  re_token_t current_token;
+  dfa->syntax = syntax;
+  fetch_token (&current_token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+  tree = parse_reg_exp (regexp, preg, &current_token, syntax, 0, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+  eor = create_tree (dfa, NULL, NULL, END_OF_RE);
+  if (tree != NULL)
+    root = create_tree (dfa, tree, eor, CONCAT);
+  else
+    root = eor;
+  if (BE (eor == NULL || root == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+  return root;
+}
+
+/* This function build the following tree, from regular expression
+   <branch1>|<branch2>:
+	   ALT
+	   / \
+	  /   \
+   <branch1> <branch2>
+
+   ALT means alternative, which represents the operator `|'.  */
+
+static bin_tree_t *
+parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
+	       reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree, *branch = NULL;
+  tree = parse_branch (regexp, preg, token, syntax, nest, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+
+  while (token->type == OP_ALT)
+    {
+      fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+      if (token->type != OP_ALT && token->type != END_OF_RE
+	  && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
+	{
+	  branch = parse_branch (regexp, preg, token, syntax, nest, err);
+	  if (BE (*err != REG_NOERROR && branch == NULL, 0))
+	    return NULL;
+	}
+      else
+	branch = NULL;
+      tree = create_tree (dfa, tree, branch, OP_ALT);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+    }
+  return tree;
+}
+
+/* This function build the following tree, from regular expression
+   <exp1><exp2>:
+	CAT
+	/ \
+       /   \
+   <exp1> <exp2>
+
+   CAT means concatenation.  */
+
+static bin_tree_t *
+parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
+	      reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  bin_tree_t *tree, *exp;
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  tree = parse_expression (regexp, preg, token, syntax, nest, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+
+  while (token->type != OP_ALT && token->type != END_OF_RE
+	 && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
+    {
+      exp = parse_expression (regexp, preg, token, syntax, nest, err);
+      if (BE (*err != REG_NOERROR && exp == NULL, 0))
+	{
+	  return NULL;
+	}
+      if (tree != NULL && exp != NULL)
+	{
+	  tree = create_tree (dfa, tree, exp, CONCAT);
+	  if (tree == NULL)
+	    {
+	      *err = REG_ESPACE;
+	      return NULL;
+	    }
+	}
+      else if (tree == NULL)
+	tree = exp;
+      /* Otherwise exp == NULL, we don't need to create new tree.  */
+    }
+  return tree;
+}
+
+/* This function build the following tree, from regular expression a*:
+	 *
+	 |
+	 a
+*/
+
+static bin_tree_t *
+parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
+		  reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree;
+  switch (token->type)
+    {
+    case CHARACTER:
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+	{
+	  while (!re_string_eoi (regexp)
+		 && !re_string_first_byte (regexp, re_string_cur_idx (regexp)))
+	    {
+	      bin_tree_t *mbc_remain;
+	      fetch_token (token, regexp, syntax);
+	      mbc_remain = create_token_tree (dfa, NULL, NULL, token);
+	      tree = create_tree (dfa, tree, mbc_remain, CONCAT);
+	      if (BE (mbc_remain == NULL || tree == NULL, 0))
+		{
+		  *err = REG_ESPACE;
+		  return NULL;
+		}
+	    }
+	}
+#endif
+      break;
+    case OP_OPEN_SUBEXP:
+      tree = parse_sub_exp (regexp, preg, token, syntax, nest + 1, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_OPEN_BRACKET:
+      tree = parse_bracket_exp (regexp, dfa, token, syntax, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_BACK_REF:
+      if (!BE (dfa->completed_bkref_map & (1 << token->opr.idx), 1))
+	{
+	  *err = REG_ESUBREG;
+	  return NULL;
+	}
+      dfa->used_bkref_map |= 1 << token->opr.idx;
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+      ++dfa->nbackref;
+      dfa->has_mb_node = 1;
+      break;
+    case OP_OPEN_DUP_NUM:
+      if (syntax & RE_CONTEXT_INVALID_DUP)
+	{
+	  *err = REG_BADRPT;
+	  return NULL;
+	}
+      /* FALLTHROUGH */
+    case OP_DUP_ASTERISK:
+    case OP_DUP_PLUS:
+    case OP_DUP_QUESTION:
+      if (syntax & RE_CONTEXT_INVALID_OPS)
+	{
+	  *err = REG_BADRPT;
+	  return NULL;
+	}
+      else if (syntax & RE_CONTEXT_INDEP_OPS)
+	{
+	  fetch_token (token, regexp, syntax);
+	  return parse_expression (regexp, preg, token, syntax, nest, err);
+	}
+      /* else fall through  */
+    case OP_CLOSE_SUBEXP:
+      if ((token->type == OP_CLOSE_SUBEXP) &&
+	  !(syntax & RE_UNMATCHED_RIGHT_PAREN_ORD))
+	{
+	  *err = REG_ERPAREN;
+	  return NULL;
+	}
+      /* else fall through  */
+    case OP_CLOSE_DUP_NUM:
+      /* We treat it as a normal character.  */
+
+      /* Then we can these characters as normal characters.  */
+      token->type = CHARACTER;
+      /* mb_partial and word_char bits should be initialized already
+	 by peek_token.  */
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+      break;
+    case ANCHOR:
+      if ((token->opr.ctx_type
+	   & (WORD_DELIM | NOT_WORD_DELIM | WORD_FIRST | WORD_LAST))
+	  && dfa->word_ops_used == 0)
+	init_word_char (dfa);
+      if (token->opr.ctx_type == WORD_DELIM
+          || token->opr.ctx_type == NOT_WORD_DELIM)
+	{
+	  bin_tree_t *tree_first, *tree_last;
+	  if (token->opr.ctx_type == WORD_DELIM)
+	    {
+	      token->opr.ctx_type = WORD_FIRST;
+	      tree_first = create_token_tree (dfa, NULL, NULL, token);
+	      token->opr.ctx_type = WORD_LAST;
+            }
+          else
+            {
+	      token->opr.ctx_type = INSIDE_WORD;
+	      tree_first = create_token_tree (dfa, NULL, NULL, token);
+	      token->opr.ctx_type = INSIDE_NOTWORD;
+            }
+	  tree_last = create_token_tree (dfa, NULL, NULL, token);
+	  tree = create_tree (dfa, tree_first, tree_last, OP_ALT);
+	  if (BE (tree_first == NULL || tree_last == NULL || tree == NULL, 0))
+	    {
+	      *err = REG_ESPACE;
+	      return NULL;
+	    }
+	}
+      else
+	{
+	  tree = create_token_tree (dfa, NULL, NULL, token);
+	  if (BE (tree == NULL, 0))
+	    {
+	      *err = REG_ESPACE;
+	      return NULL;
+	    }
+	}
+      /* We must return here, since ANCHORs can't be followed
+	 by repetition operators.
+	 eg. RE"^*" is invalid or "<ANCHOR(^)><CHAR(*)>",
+	     it must not be "<ANCHOR(^)><REPEAT(*)>".  */
+      fetch_token (token, regexp, syntax);
+      return tree;
+    case OP_PERIOD:
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+      if (dfa->mb_cur_max > 1)
+	dfa->has_mb_node = 1;
+      break;
+    case OP_WORD:
+    case OP_NOTWORD:
+      tree = build_charclass_op (dfa, regexp->trans,
+				 (const unsigned char *) "alnum",
+				 (const unsigned char *) "_",
+				 token->type == OP_NOTWORD, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_SPACE:
+    case OP_NOTSPACE:
+      tree = build_charclass_op (dfa, regexp->trans,
+				 (const unsigned char *) "space",
+				 (const unsigned char *) "",
+				 token->type == OP_NOTSPACE, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_ALT:
+    case END_OF_RE:
+      return NULL;
+    case BACK_SLASH:
+      *err = REG_EESCAPE;
+      return NULL;
+    default:
+      /* Must not happen?  */
+#ifdef DEBUG
+      assert (0);
+#endif
+      return NULL;
+    }
+  fetch_token (token, regexp, syntax);
+
+  while (token->type == OP_DUP_ASTERISK || token->type == OP_DUP_PLUS
+	 || token->type == OP_DUP_QUESTION || token->type == OP_OPEN_DUP_NUM)
+    {
+      tree = parse_dup_op (tree, regexp, dfa, token, syntax, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      /* In BRE consecutive duplications are not allowed.  */
+      if ((syntax & RE_CONTEXT_INVALID_DUP)
+	  && (token->type == OP_DUP_ASTERISK
+	      || token->type == OP_OPEN_DUP_NUM))
+	{
+	  *err = REG_BADRPT;
+	  return NULL;
+	}
+    }
+
+  return tree;
+}
+
+/* This function build the following tree, from regular expression
+   (<reg_exp>):
+	 SUBEXP
+	    |
+	<reg_exp>
+*/
+
+static bin_tree_t *
+parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
+	       reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree;
+  size_t cur_nsub;
+  cur_nsub = preg->re_nsub++;
+
+  fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+
+  /* The subexpression may be a null string.  */
+  if (token->type == OP_CLOSE_SUBEXP)
+    tree = NULL;
+  else
+    {
+      tree = parse_reg_exp (regexp, preg, token, syntax, nest, err);
+      if (BE (*err == REG_NOERROR && token->type != OP_CLOSE_SUBEXP, 0))
+        *err = REG_EPAREN;
+      if (BE (*err != REG_NOERROR, 0))
+	return NULL;
+    }
+
+  if (cur_nsub <= '9' - '1')
+    dfa->completed_bkref_map |= 1 << cur_nsub;
+
+  tree = create_tree (dfa, tree, NULL, SUBEXP);
+  if (BE (tree == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+  tree->token.opr.idx = cur_nsub;
+  return tree;
+}
+
+/* This function parse repetition operators like "*", "+", "{1,3}" etc.  */
+
+static bin_tree_t *
+parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
+	      re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err)
+{
+  bin_tree_t *tree = NULL, *old_tree = NULL;
+  Idx i, start, end, start_idx = re_string_cur_idx (regexp);
+  re_token_t start_token = *token;
+
+  if (token->type == OP_OPEN_DUP_NUM)
+    {
+      end = 0;
+      start = fetch_number (regexp, token, syntax);
+      if (start == REG_MISSING)
+	{
+	  if (token->type == CHARACTER && token->opr.c == ',')
+	    start = 0; /* We treat "{,m}" as "{0,m}".  */
+	  else
+	    {
+	      *err = REG_BADBR; /* <re>{} is invalid.  */
+	      return NULL;
+	    }
+	}
+      if (BE (start != REG_ERROR, 1))
+	{
+	  /* We treat "{n}" as "{n,n}".  */
+	  end = ((token->type == OP_CLOSE_DUP_NUM) ? start
+		 : ((token->type == CHARACTER && token->opr.c == ',')
+		    ? fetch_number (regexp, token, syntax) : REG_ERROR));
+	}
+      if (BE (start == REG_ERROR || end == REG_ERROR, 0))
+	{
+	  /* Invalid sequence.  */
+	  if (BE (!(syntax & RE_INVALID_INTERVAL_ORD), 0))
+	    {
+	      if (token->type == END_OF_RE)
+		*err = REG_EBRACE;
+	      else
+		*err = REG_BADBR;
+
+	      return NULL;
+	    }
+
+	  /* If the syntax bit is set, rollback.  */
+	  re_string_set_index (regexp, start_idx);
+	  *token = start_token;
+	  token->type = CHARACTER;
+	  /* mb_partial and word_char bits should be already initialized by
+	     peek_token.  */
+	  return elem;
+	}
+
+      if (BE (end != REG_MISSING && start > end, 0))
+	{
+	  /* First number greater than second.  */
+	  *err = REG_BADBR;
+	  return NULL;
+	}
+    }
+  else
+    {
+      start = (token->type == OP_DUP_PLUS) ? 1 : 0;
+      end = (token->type == OP_DUP_QUESTION) ? 1 : REG_MISSING;
+    }
+
+  fetch_token (token, regexp, syntax);
+
+  if (BE (elem == NULL, 0))
+    return NULL;
+  if (BE (start == 0 && end == 0, 0))
+    {
+      postorder (elem, free_tree, NULL);
+      return NULL;
+    }
+
+  /* Extract "<re>{n,m}" to "<re><re>...<re><re>{0,<m-n>}".  */
+  if (BE (start > 0, 0))
+    {
+      tree = elem;
+      for (i = 2; i <= start; ++i)
+	{
+	  elem = duplicate_tree (elem, dfa);
+	  tree = create_tree (dfa, tree, elem, CONCAT);
+	  if (BE (elem == NULL || tree == NULL, 0))
+	    goto parse_dup_op_espace;
+	}
+
+      if (start == end)
+	return tree;
+
+      /* Duplicate ELEM before it is marked optional.  */
+      elem = duplicate_tree (elem, dfa);
+      old_tree = tree;
+    }
+  else
+    old_tree = NULL;
+
+  if (elem->token.type == SUBEXP)
+    postorder (elem, mark_opt_subexp, (void *) (long) elem->token.opr.idx);
+
+  tree = create_tree (dfa, elem, NULL,
+		      (end == REG_MISSING ? OP_DUP_ASTERISK : OP_ALT));
+  if (BE (tree == NULL, 0))
+    goto parse_dup_op_espace;
+
+  /* This loop is actually executed only when end != REG_MISSING,
+     to rewrite <re>{0,n} as (<re>(<re>...<re>?)?)?...  We have
+     already created the start+1-th copy.  */
+  if ((Idx) -1 < 0 || end != REG_MISSING)
+    for (i = start + 2; i <= end; ++i)
+      {
+	elem = duplicate_tree (elem, dfa);
+	tree = create_tree (dfa, tree, elem, CONCAT);
+	if (BE (elem == NULL || tree == NULL, 0))
+	  goto parse_dup_op_espace;
+
+	tree = create_tree (dfa, tree, NULL, OP_ALT);
+	if (BE (tree == NULL, 0))
+	  goto parse_dup_op_espace;
+      }
+
+  if (old_tree)
+    tree = create_tree (dfa, old_tree, tree, CONCAT);
+
+  return tree;
+
+ parse_dup_op_espace:
+  *err = REG_ESPACE;
+  return NULL;
+}
+
+/* Size of the names for collating symbol/equivalence_class/character_class.
+   I'm not sure, but maybe enough.  */
+#define BRACKET_NAME_BUF_SIZE 32
+
+#ifndef _LIBC
+  /* Local function for parse_bracket_exp only used in case of NOT _LIBC.
+     Build the range expression which starts from START_ELEM, and ends
+     at END_ELEM.  The result are written to MBCSET and SBCSET.
+     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
+     mbcset->range_ends, is a pointer argument sinse we may
+     update it.  */
+
+static reg_errcode_t
+internal_function
+# ifdef RE_ENABLE_I18N
+build_range_exp (bitset_t sbcset, re_charset_t *mbcset, Idx *range_alloc,
+		 bracket_elem_t *start_elem, bracket_elem_t *end_elem)
+# else /* not RE_ENABLE_I18N */
+build_range_exp (bitset_t sbcset, bracket_elem_t *start_elem,
+		 bracket_elem_t *end_elem)
+# endif /* not RE_ENABLE_I18N */
+{
+  unsigned int start_ch, end_ch;
+  /* Equivalence Classes and Character Classes can't be a range start/end.  */
+  if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
+	  || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
+	  0))
+    return REG_ERANGE;
+
+  /* We can handle no multi character collating elements without libc
+     support.  */
+  if (BE ((start_elem->type == COLL_SYM
+	   && strlen ((char *) start_elem->opr.name) > 1)
+	  || (end_elem->type == COLL_SYM
+	      && strlen ((char *) end_elem->opr.name) > 1), 0))
+    return REG_ECOLLATE;
+
+# ifdef RE_ENABLE_I18N
+  {
+    wchar_t wc;
+    wint_t start_wc;
+    wint_t end_wc;
+    wchar_t cmp_buf[6] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
+
+    start_ch = ((start_elem->type == SB_CHAR) ? start_elem->opr.ch
+		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
+		   : 0));
+    end_ch = ((end_elem->type == SB_CHAR) ? end_elem->opr.ch
+	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
+		 : 0));
+    start_wc = ((start_elem->type == SB_CHAR || start_elem->type == COLL_SYM)
+		? __btowc (start_ch) : start_elem->opr.wch);
+    end_wc = ((end_elem->type == SB_CHAR || end_elem->type == COLL_SYM)
+	      ? __btowc (end_ch) : end_elem->opr.wch);
+    if (start_wc == WEOF || end_wc == WEOF)
+      return REG_ECOLLATE;
+    cmp_buf[0] = start_wc;
+    cmp_buf[4] = end_wc;
+    if (wcscoll (cmp_buf, cmp_buf + 4) > 0)
+      return REG_ERANGE;
+
+    /* Got valid collation sequence values, add them as a new entry.
+       However, for !_LIBC we have no collation elements: if the
+       character set is single byte, the single byte character set
+       that we build below suffices.  parse_bracket_exp passes
+       no MBCSET if dfa->mb_cur_max == 1.  */
+    if (mbcset)
+      {
+        /* Check the space of the arrays.  */
+        if (BE (*range_alloc == mbcset->nranges, 0))
+          {
+	    /* There is not enough space, need realloc.  */
+	    wchar_t *new_array_start, *new_array_end;
+	    Idx new_nranges;
+
+	    /* +1 in case of mbcset->nranges is 0.  */
+	    new_nranges = 2 * mbcset->nranges + 1;
+	    /* Use realloc since mbcset->range_starts and mbcset->range_ends
+	       are NULL if *range_alloc == 0.  */
+	    new_array_start = re_realloc (mbcset->range_starts, wchar_t,
+				          new_nranges);
+	    new_array_end = re_realloc (mbcset->range_ends, wchar_t,
+				        new_nranges);
+
+	    if (BE (new_array_start == NULL || new_array_end == NULL, 0))
+	      return REG_ESPACE;
+
+	    mbcset->range_starts = new_array_start;
+	    mbcset->range_ends = new_array_end;
+	    *range_alloc = new_nranges;
+          }
+
+        mbcset->range_starts[mbcset->nranges] = start_wc;
+        mbcset->range_ends[mbcset->nranges++] = end_wc;
+      }
+
+    /* Build the table for single byte characters.  */
+    for (wc = 0; wc < SBC_MAX; ++wc)
+      {
+	cmp_buf[2] = wc;
+	if (wcscoll (cmp_buf, cmp_buf + 2) <= 0
+	    && wcscoll (cmp_buf + 2, cmp_buf + 4) <= 0)
+	  bitset_set (sbcset, wc);
+      }
+  }
+# else /* not RE_ENABLE_I18N */
+  {
+    unsigned int ch;
+    start_ch = ((start_elem->type == SB_CHAR ) ? start_elem->opr.ch
+		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
+		   : 0));
+    end_ch = ((end_elem->type == SB_CHAR ) ? end_elem->opr.ch
+	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
+		 : 0));
+    if (start_ch > end_ch)
+      return REG_ERANGE;
+    /* Build the table for single byte characters.  */
+    for (ch = 0; ch < SBC_MAX; ++ch)
+      if (start_ch <= ch  && ch <= end_ch)
+	bitset_set (sbcset, ch);
+  }
+# endif /* not RE_ENABLE_I18N */
+  return REG_NOERROR;
+}
+#endif /* not _LIBC */
+
+#ifndef _LIBC
+/* Helper function for parse_bracket_exp only used in case of NOT _LIBC..
+   Build the collating element which is represented by NAME.
+   The result are written to MBCSET and SBCSET.
+   COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
+   pointer argument since we may update it.  */
+
+static reg_errcode_t
+internal_function
+build_collating_symbol (bitset_t sbcset,
+# ifdef RE_ENABLE_I18N
+			re_charset_t *mbcset, Idx *coll_sym_alloc,
+# endif
+			const unsigned char *name)
+{
+  size_t name_len = strlen ((const char *) name);
+  if (BE (name_len != 1, 0))
+    return REG_ECOLLATE;
+  else
+    {
+      bitset_set (sbcset, name[0]);
+      return REG_NOERROR;
+    }
+}
+#endif /* not _LIBC */
+
+/* This function parse bracket expression like "[abc]", "[a-c]",
+   "[[.a-a.]]" etc.  */
+
+static bin_tree_t *
+parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
+		   reg_syntax_t syntax, reg_errcode_t *err)
+{
+#ifdef _LIBC
+  const unsigned char *collseqmb;
+  const char *collseqwc;
+  uint32_t nrules;
+  int32_t table_size;
+  const int32_t *symb_table;
+  const unsigned char *extra;
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Seek the collating symbol entry correspondings to NAME.
+     Return the index of the symbol in the SYMB_TABLE.  */
+
+  auto inline int32_t
+  __attribute ((always_inline))
+  seek_collating_symbol_entry (name, name_len)
+	 const unsigned char *name;
+	 size_t name_len;
+    {
+      int32_t hash = elem_hash ((const char *) name, name_len);
+      int32_t elem = hash % table_size;
+      if (symb_table[2 * elem] != 0)
+	{
+	  int32_t second = hash % (table_size - 2) + 1;
+
+	  do
+	    {
+	      /* First compare the hashing value.  */
+	      if (symb_table[2 * elem] == hash
+		  /* Compare the length of the name.  */
+		  && name_len == extra[symb_table[2 * elem + 1]]
+		  /* Compare the name.  */
+		  && memcmp (name, &extra[symb_table[2 * elem + 1] + 1],
+			     name_len) == 0)
+		{
+		  /* Yep, this is the entry.  */
+		  break;
+		}
+
+	      /* Next entry.  */
+	      elem += second;
+	    }
+	  while (symb_table[2 * elem] != 0);
+	}
+      return elem;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Look up the collation sequence value of BR_ELEM.
+     Return the value if succeeded, UINT_MAX otherwise.  */
+
+  auto inline unsigned int
+  __attribute ((always_inline))
+  lookup_collation_sequence_value (br_elem)
+	 bracket_elem_t *br_elem;
+    {
+      if (br_elem->type == SB_CHAR)
+	{
+	  /*
+	  if (MB_CUR_MAX == 1)
+	  */
+	  if (nrules == 0)
+	    return collseqmb[br_elem->opr.ch];
+	  else
+	    {
+	      wint_t wc = __btowc (br_elem->opr.ch);
+	      return __collseq_table_lookup (collseqwc, wc);
+	    }
+	}
+      else if (br_elem->type == MB_CHAR)
+	{
+	  return __collseq_table_lookup (collseqwc, br_elem->opr.wch);
+	}
+      else if (br_elem->type == COLL_SYM)
+	{
+	  size_t sym_name_len = strlen ((char *) br_elem->opr.name);
+	  if (nrules != 0)
+	    {
+	      int32_t elem, idx;
+	      elem = seek_collating_symbol_entry (br_elem->opr.name,
+						  sym_name_len);
+	      if (symb_table[2 * elem] != 0)
+		{
+		  /* We found the entry.  */
+		  idx = symb_table[2 * elem + 1];
+		  /* Skip the name of collating element name.  */
+		  idx += 1 + extra[idx];
+		  /* Skip the byte sequence of the collating element.  */
+		  idx += 1 + extra[idx];
+		  /* Adjust for the alignment.  */
+		  idx = (idx + 3) & ~3;
+		  /* Skip the multibyte collation sequence value.  */
+		  idx += sizeof (unsigned int);
+		  /* Skip the wide char sequence of the collating element.  */
+		  idx += sizeof (unsigned int) *
+		    (1 + *(unsigned int *) (extra + idx));
+		  /* Return the collation sequence value.  */
+		  return *(unsigned int *) (extra + idx);
+		}
+	      else if (symb_table[2 * elem] == 0 && sym_name_len == 1)
+		{
+		  /* No valid character.  Match it as a single byte
+		     character.  */
+		  return collseqmb[br_elem->opr.name[0]];
+		}
+	    }
+	  else if (sym_name_len == 1)
+	    return collseqmb[br_elem->opr.name[0]];
+	}
+      return UINT_MAX;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Build the range expression which starts from START_ELEM, and ends
+     at END_ELEM.  The result are written to MBCSET and SBCSET.
+     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
+     mbcset->range_ends, is a pointer argument sinse we may
+     update it.  */
+
+  auto inline reg_errcode_t
+  __attribute ((always_inline))
+  build_range_exp (sbcset, mbcset, range_alloc, start_elem, end_elem)
+	 re_charset_t *mbcset;
+	 Idx *range_alloc;
+	 bitset_t sbcset;
+	 bracket_elem_t *start_elem, *end_elem;
+    {
+      unsigned int ch;
+      uint32_t start_collseq;
+      uint32_t end_collseq;
+
+      /* Equivalence Classes and Character Classes can't be a range
+	 start/end.  */
+      if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
+	      || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
+	      0))
+	return REG_ERANGE;
+
+      start_collseq = lookup_collation_sequence_value (start_elem);
+      end_collseq = lookup_collation_sequence_value (end_elem);
+      /* Check start/end collation sequence values.  */
+      if (BE (start_collseq == UINT_MAX || end_collseq == UINT_MAX, 0))
+	return REG_ECOLLATE;
+      if (BE ((syntax & RE_NO_EMPTY_RANGES) && start_collseq > end_collseq, 0))
+	return REG_ERANGE;
+
+      /* Got valid collation sequence values, add them as a new entry.
+	 However, if we have no collation elements, and the character set
+	 is single byte, the single byte character set that we
+	 build below suffices. */
+      if (nrules > 0 || dfa->mb_cur_max > 1)
+	{
+          /* Check the space of the arrays.  */
+          if (BE (*range_alloc == mbcset->nranges, 0))
+	    {
+	      /* There is not enough space, need realloc.  */
+	      uint32_t *new_array_start;
+	      uint32_t *new_array_end;
+	      Idx new_nranges;
+
+	      /* +1 in case of mbcset->nranges is 0.  */
+	      new_nranges = 2 * mbcset->nranges + 1;
+	      new_array_start = re_realloc (mbcset->range_starts, uint32_t,
+					    new_nranges);
+	      new_array_end = re_realloc (mbcset->range_ends, uint32_t,
+				          new_nranges);
+
+	      if (BE (new_array_start == NULL || new_array_end == NULL, 0))
+	        return REG_ESPACE;
+
+	      mbcset->range_starts = new_array_start;
+	      mbcset->range_ends = new_array_end;
+	      *range_alloc = new_nranges;
+	    }
+
+          mbcset->range_starts[mbcset->nranges] = start_collseq;
+          mbcset->range_ends[mbcset->nranges++] = end_collseq;
+	}
+
+      /* Build the table for single byte characters.  */
+      for (ch = 0; ch < SBC_MAX; ch++)
+	{
+	  uint32_t ch_collseq;
+	  /*
+	  if (MB_CUR_MAX == 1)
+	  */
+	  if (nrules == 0)
+	    ch_collseq = collseqmb[ch];
+	  else
+	    ch_collseq = __collseq_table_lookup (collseqwc, __btowc (ch));
+	  if (start_collseq <= ch_collseq && ch_collseq <= end_collseq)
+	    bitset_set (sbcset, ch);
+	}
+      return REG_NOERROR;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Build the collating element which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
+     pointer argument sinse we may update it.  */
+
+  auto inline reg_errcode_t
+  __attribute ((always_inline))
+  build_collating_symbol (sbcset, mbcset, coll_sym_alloc, name)
+	 re_charset_t *mbcset;
+	 Idx *coll_sym_alloc;
+	 bitset_t sbcset;
+	 const unsigned char *name;
+    {
+      int32_t elem, idx;
+      size_t name_len = strlen ((const char *) name);
+      if (nrules != 0)
+	{
+	  elem = seek_collating_symbol_entry (name, name_len);
+	  if (symb_table[2 * elem] != 0)
+	    {
+	      /* We found the entry.  */
+	      idx = symb_table[2 * elem + 1];
+	      /* Skip the name of collating element name.  */
+	      idx += 1 + extra[idx];
+	    }
+	  else if (symb_table[2 * elem] == 0 && name_len == 1)
+	    {
+	      /* No valid character, treat it as a normal
+		 character.  */
+	      bitset_set (sbcset, name[0]);
+	      return REG_NOERROR;
+	    }
+	  else
+	    return REG_ECOLLATE;
+
+	  /* Got valid collation sequence, add it as a new entry.  */
+	  /* Check the space of the arrays.  */
+	  if (BE (*coll_sym_alloc == mbcset->ncoll_syms, 0))
+	    {
+	      /* Not enough, realloc it.  */
+	      /* +1 in case of mbcset->ncoll_syms is 0.  */
+	      Idx new_coll_sym_alloc = 2 * mbcset->ncoll_syms + 1;
+	      /* Use realloc since mbcset->coll_syms is NULL
+		 if *alloc == 0.  */
+	      int32_t *new_coll_syms = re_realloc (mbcset->coll_syms, int32_t,
+						   new_coll_sym_alloc);
+	      if (BE (new_coll_syms == NULL, 0))
+		return REG_ESPACE;
+	      mbcset->coll_syms = new_coll_syms;
+	      *coll_sym_alloc = new_coll_sym_alloc;
+	    }
+	  mbcset->coll_syms[mbcset->ncoll_syms++] = idx;
+	  return REG_NOERROR;
+	}
+      else
+	{
+	  if (BE (name_len != 1, 0))
+	    return REG_ECOLLATE;
+	  else
+	    {
+	      bitset_set (sbcset, name[0]);
+	      return REG_NOERROR;
+	    }
+	}
+    }
+#endif
+
+  re_token_t br_token;
+  re_bitset_ptr_t sbcset;
+#ifdef RE_ENABLE_I18N
+  re_charset_t *mbcset;
+  Idx coll_sym_alloc = 0, range_alloc = 0, mbchar_alloc = 0;
+  Idx equiv_class_alloc = 0, char_class_alloc = 0;
+#endif /* not RE_ENABLE_I18N */
+  bool non_match = false;
+  bin_tree_t *work_tree;
+  int token_len;
+  bool first_round = true;
+#ifdef _LIBC
+  collseqmb = (const unsigned char *)
+    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
+  nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules)
+    {
+      /*
+      if (MB_CUR_MAX > 1)
+      */
+      collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+      table_size = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_SYMB_HASH_SIZEMB);
+      symb_table = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+						  _NL_COLLATE_SYMB_TABLEMB);
+      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+						   _NL_COLLATE_SYMB_EXTRAMB);
+    }
+#endif
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+#ifdef RE_ENABLE_I18N
+  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
+#endif /* RE_ENABLE_I18N */
+#ifdef RE_ENABLE_I18N
+  if (BE (sbcset == NULL || mbcset == NULL, 0))
+#else
+  if (BE (sbcset == NULL, 0))
+#endif /* RE_ENABLE_I18N */
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  token_len = peek_token_bracket (token, regexp, syntax);
+  if (BE (token->type == END_OF_RE, 0))
+    {
+      *err = REG_BADPAT;
+      goto parse_bracket_exp_free_return;
+    }
+  if (token->type == OP_NON_MATCH_LIST)
+    {
+#ifdef RE_ENABLE_I18N
+      mbcset->non_match = 1;
+#endif /* not RE_ENABLE_I18N */
+      non_match = true;
+      if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
+	bitset_set (sbcset, '\0');
+      re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+      token_len = peek_token_bracket (token, regexp, syntax);
+      if (BE (token->type == END_OF_RE, 0))
+	{
+	  *err = REG_BADPAT;
+	  goto parse_bracket_exp_free_return;
+	}
+    }
+
+  /* We treat the first ']' as a normal character.  */
+  if (token->type == OP_CLOSE_BRACKET)
+    token->type = CHARACTER;
+
+  while (1)
+    {
+      bracket_elem_t start_elem, end_elem;
+      unsigned char start_name_buf[BRACKET_NAME_BUF_SIZE];
+      unsigned char end_name_buf[BRACKET_NAME_BUF_SIZE];
+      reg_errcode_t ret;
+      int token_len2 = 0;
+      bool is_range_exp = false;
+      re_token_t token2;
+
+      start_elem.opr.name = start_name_buf;
+      ret = parse_bracket_element (&start_elem, regexp, token, token_len, dfa,
+				   syntax, first_round);
+      if (BE (ret != REG_NOERROR, 0))
+	{
+	  *err = ret;
+	  goto parse_bracket_exp_free_return;
+	}
+      first_round = false;
+
+      /* Get information about the next token.  We need it in any case.  */
+      token_len = peek_token_bracket (token, regexp, syntax);
+
+      /* Do not check for ranges if we know they are not allowed.  */
+      if (start_elem.type != CHAR_CLASS && start_elem.type != EQUIV_CLASS)
+	{
+	  if (BE (token->type == END_OF_RE, 0))
+	    {
+	      *err = REG_EBRACK;
+	      goto parse_bracket_exp_free_return;
+	    }
+	  if (token->type == OP_CHARSET_RANGE)
+	    {
+	      re_string_skip_bytes (regexp, token_len); /* Skip '-'.  */
+	      token_len2 = peek_token_bracket (&token2, regexp, syntax);
+	      if (BE (token2.type == END_OF_RE, 0))
+		{
+		  *err = REG_EBRACK;
+		  goto parse_bracket_exp_free_return;
+		}
+	      if (token2.type == OP_CLOSE_BRACKET)
+		{
+		  /* We treat the last '-' as a normal character.  */
+		  re_string_skip_bytes (regexp, -token_len);
+		  token->type = CHARACTER;
+		}
+	      else
+		is_range_exp = true;
+	    }
+	}
+
+      if (is_range_exp == true)
+	{
+	  end_elem.opr.name = end_name_buf;
+	  ret = parse_bracket_element (&end_elem, regexp, &token2, token_len2,
+				       dfa, syntax, true);
+	  if (BE (ret != REG_NOERROR, 0))
+	    {
+	      *err = ret;
+	      goto parse_bracket_exp_free_return;
+	    }
+
+	  token_len = peek_token_bracket (token, regexp, syntax);
+
+#ifdef _LIBC
+	  *err = build_range_exp (sbcset, mbcset, &range_alloc,
+				  &start_elem, &end_elem);
+#else
+# ifdef RE_ENABLE_I18N
+	  *err = build_range_exp (sbcset,
+				  dfa->mb_cur_max > 1 ? mbcset : NULL,
+				  &range_alloc, &start_elem, &end_elem);
+# else
+	  *err = build_range_exp (sbcset, &start_elem, &end_elem);
+# endif
+#endif /* RE_ENABLE_I18N */
+	  if (BE (*err != REG_NOERROR, 0))
+	    goto parse_bracket_exp_free_return;
+	}
+      else
+	{
+	  switch (start_elem.type)
+	    {
+	    case SB_CHAR:
+	      bitset_set (sbcset, start_elem.opr.ch);
+	      break;
+#ifdef RE_ENABLE_I18N
+	    case MB_CHAR:
+	      /* Check whether the array has enough space.  */
+	      if (BE (mbchar_alloc == mbcset->nmbchars, 0))
+		{
+		  wchar_t *new_mbchars;
+		  /* Not enough, realloc it.  */
+		  /* +1 in case of mbcset->nmbchars is 0.  */
+		  mbchar_alloc = 2 * mbcset->nmbchars + 1;
+		  /* Use realloc since array is NULL if *alloc == 0.  */
+		  new_mbchars = re_realloc (mbcset->mbchars, wchar_t,
+					    mbchar_alloc);
+		  if (BE (new_mbchars == NULL, 0))
+		    goto parse_bracket_exp_espace;
+		  mbcset->mbchars = new_mbchars;
+		}
+	      mbcset->mbchars[mbcset->nmbchars++] = start_elem.opr.wch;
+	      break;
+#endif /* RE_ENABLE_I18N */
+	    case EQUIV_CLASS:
+	      *err = build_equiv_class (sbcset,
+#ifdef RE_ENABLE_I18N
+					mbcset, &equiv_class_alloc,
+#endif /* RE_ENABLE_I18N */
+					start_elem.opr.name);
+	      if (BE (*err != REG_NOERROR, 0))
+		goto parse_bracket_exp_free_return;
+	      break;
+	    case COLL_SYM:
+	      *err = build_collating_symbol (sbcset,
+#ifdef RE_ENABLE_I18N
+					     mbcset, &coll_sym_alloc,
+#endif /* RE_ENABLE_I18N */
+					     start_elem.opr.name);
+	      if (BE (*err != REG_NOERROR, 0))
+		goto parse_bracket_exp_free_return;
+	      break;
+	    case CHAR_CLASS:
+	      *err = build_charclass (regexp->trans, sbcset,
+#ifdef RE_ENABLE_I18N
+				      mbcset, &char_class_alloc,
+#endif /* RE_ENABLE_I18N */
+				      start_elem.opr.name, syntax);
+	      if (BE (*err != REG_NOERROR, 0))
+	       goto parse_bracket_exp_free_return;
+	      break;
+	    default:
+	      assert (0);
+	      break;
+	    }
+	}
+      if (BE (token->type == END_OF_RE, 0))
+	{
+	  *err = REG_EBRACK;
+	  goto parse_bracket_exp_free_return;
+	}
+      if (token->type == OP_CLOSE_BRACKET)
+	break;
+    }
+
+  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+
+  /* If it is non-matching list.  */
+  if (non_match)
+    bitset_not (sbcset);
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure only single byte characters are set.  */
+  if (dfa->mb_cur_max > 1)
+    bitset_mask (sbcset, dfa->sb_char);
+
+  if (mbcset->nmbchars || mbcset->ncoll_syms || mbcset->nequiv_classes
+      || mbcset->nranges || (dfa->mb_cur_max > 1 && (mbcset->nchar_classes
+						     || mbcset->non_match)))
+    {
+      bin_tree_t *mbc_tree;
+      int sbc_idx;
+      /* Build a tree for complex bracket.  */
+      dfa->has_mb_node = 1;
+      br_token.type = COMPLEX_BRACKET;
+      br_token.opr.mbcset = mbcset;
+      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (mbc_tree == NULL, 0))
+	goto parse_bracket_exp_espace;
+      for (sbc_idx = 0; sbc_idx < BITSET_WORDS; ++sbc_idx)
+	if (sbcset[sbc_idx])
+	  break;
+      /* If there are no bits set in sbcset, there is no point
+	 of having both SIMPLE_BRACKET and COMPLEX_BRACKET.  */
+      if (sbc_idx < BITSET_WORDS)
+	{
+          /* Build a tree for simple bracket.  */
+          br_token.type = SIMPLE_BRACKET;
+          br_token.opr.sbcset = sbcset;
+          work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+          if (BE (work_tree == NULL, 0))
+            goto parse_bracket_exp_espace;
+
+          /* Then join them by ALT node.  */
+          work_tree = create_tree (dfa, work_tree, mbc_tree, OP_ALT);
+          if (BE (work_tree == NULL, 0))
+            goto parse_bracket_exp_espace;
+	}
+      else
+	{
+	  re_free (sbcset);
+	  work_tree = mbc_tree;
+	}
+    }
+  else
+#endif /* not RE_ENABLE_I18N */
+    {
+#ifdef RE_ENABLE_I18N
+      free_charset (mbcset);
+#endif
+      /* Build a tree for simple bracket.  */
+      br_token.type = SIMPLE_BRACKET;
+      br_token.opr.sbcset = sbcset;
+      work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (work_tree == NULL, 0))
+        goto parse_bracket_exp_espace;
+    }
+  return work_tree;
+
+ parse_bracket_exp_espace:
+  *err = REG_ESPACE;
+ parse_bracket_exp_free_return:
+  re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+  free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+  return NULL;
+}
+
+/* Parse an element in the bracket expression.  */
+
+static reg_errcode_t
+parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp,
+		       re_token_t *token, int token_len, re_dfa_t *dfa,
+		       reg_syntax_t syntax, bool accept_hyphen)
+{
+#ifdef RE_ENABLE_I18N
+  int cur_char_size;
+  cur_char_size = re_string_char_size_at (regexp, re_string_cur_idx (regexp));
+  if (cur_char_size > 1)
+    {
+      elem->type = MB_CHAR;
+      elem->opr.wch = re_string_wchar_at (regexp, re_string_cur_idx (regexp));
+      re_string_skip_bytes (regexp, cur_char_size);
+      return REG_NOERROR;
+    }
+#endif /* RE_ENABLE_I18N */
+  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+  if (token->type == OP_OPEN_COLL_ELEM || token->type == OP_OPEN_CHAR_CLASS
+      || token->type == OP_OPEN_EQUIV_CLASS)
+    return parse_bracket_symbol (elem, regexp, token);
+  if (BE (token->type == OP_CHARSET_RANGE, 0) && !accept_hyphen)
+    {
+      /* A '-' must only appear as anything but a range indicator before
+	 the closing bracket.  Everything else is an error.  */
+      re_token_t token2;
+      (void) peek_token_bracket (&token2, regexp, syntax);
+      if (token2.type != OP_CLOSE_BRACKET)
+	/* The actual error value is not standardized since this whole
+	   case is undefined.  But ERANGE makes good sense.  */
+	return REG_ERANGE;
+    }
+  elem->type = SB_CHAR;
+  elem->opr.ch = token->opr.c;
+  return REG_NOERROR;
+}
+
+/* Parse a bracket symbol in the bracket expression.  Bracket symbols are
+   such as [:<character_class>:], [.<collating_element>.], and
+   [=<equivalent_class>=].  */
+
+static reg_errcode_t
+parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp,
+		      re_token_t *token)
+{
+  unsigned char ch, delim = token->opr.c;
+  int i = 0;
+  if (re_string_eoi(regexp))
+    return REG_EBRACK;
+  for (;; ++i)
+    {
+      if (i >= BRACKET_NAME_BUF_SIZE)
+	return REG_EBRACK;
+      if (token->type == OP_OPEN_CHAR_CLASS)
+	ch = re_string_fetch_byte_case (regexp);
+      else
+	ch = re_string_fetch_byte (regexp);
+      if (re_string_eoi(regexp))
+	return REG_EBRACK;
+      if (ch == delim && re_string_peek_byte (regexp, 0) == ']')
+	break;
+      elem->opr.name[i] = ch;
+    }
+  re_string_skip_bytes (regexp, 1);
+  elem->opr.name[i] = '\0';
+  switch (token->type)
+    {
+    case OP_OPEN_COLL_ELEM:
+      elem->type = COLL_SYM;
+      break;
+    case OP_OPEN_EQUIV_CLASS:
+      elem->type = EQUIV_CLASS;
+      break;
+    case OP_OPEN_CHAR_CLASS:
+      elem->type = CHAR_CLASS;
+      break;
+    default:
+      break;
+    }
+  return REG_NOERROR;
+}
+
+  /* Helper function for parse_bracket_exp.
+     Build the equivalence class which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     EQUIV_CLASS_ALLOC is the allocated size of mbcset->equiv_classes,
+     is a pointer argument sinse we may update it.  */
+
+static reg_errcode_t
+#ifdef RE_ENABLE_I18N
+build_equiv_class (bitset_t sbcset, re_charset_t *mbcset,
+		   Idx *equiv_class_alloc, const unsigned char *name)
+#else /* not RE_ENABLE_I18N */
+build_equiv_class (bitset_t sbcset, const unsigned char *name)
+#endif /* not RE_ENABLE_I18N */
+{
+#ifdef _LIBC
+  uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules != 0)
+    {
+      const int32_t *table, *indirect;
+      const unsigned char *weights, *extra, *cp;
+      unsigned char char_buf[2];
+      int32_t idx1, idx2;
+      unsigned int ch;
+      size_t len;
+      /* This #include defines a local function!  */
+# include <locale/weight.h>
+      /* Calculate the index for equivalence class.  */
+      cp = name;
+      table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+      weights = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+					       _NL_COLLATE_WEIGHTMB);
+      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+						   _NL_COLLATE_EXTRAMB);
+      indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+						_NL_COLLATE_INDIRECTMB);
+      idx1 = findidx (&cp);
+      if (BE (idx1 == 0 || cp < name + strlen ((const char *) name), 0))
+	/* This isn't a valid character.  */
+	return REG_ECOLLATE;
+
+      /* Build single byte matcing table for this equivalence class.  */
+      char_buf[1] = (unsigned char) '\0';
+      len = weights[idx1];
+      for (ch = 0; ch < SBC_MAX; ++ch)
+	{
+	  char_buf[0] = ch;
+	  cp = char_buf;
+	  idx2 = findidx (&cp);
+/*
+	  idx2 = table[ch];
+*/
+	  if (idx2 == 0)
+	    /* This isn't a valid character.  */
+	    continue;
+	  if (len == weights[idx2])
+	    {
+	      int cnt = 0;
+	      while (cnt <= len &&
+		     weights[idx1 + 1 + cnt] == weights[idx2 + 1 + cnt])
+		++cnt;
+
+	      if (cnt > len)
+		bitset_set (sbcset, ch);
+	    }
+	}
+      /* Check whether the array has enough space.  */
+      if (BE (*equiv_class_alloc == mbcset->nequiv_classes, 0))
+	{
+	  /* Not enough, realloc it.  */
+	  /* +1 in case of mbcset->nequiv_classes is 0.  */
+	  Idx new_equiv_class_alloc = 2 * mbcset->nequiv_classes + 1;
+	  /* Use realloc since the array is NULL if *alloc == 0.  */
+	  int32_t *new_equiv_classes = re_realloc (mbcset->equiv_classes,
+						   int32_t,
+						   new_equiv_class_alloc);
+	  if (BE (new_equiv_classes == NULL, 0))
+	    return REG_ESPACE;
+	  mbcset->equiv_classes = new_equiv_classes;
+	  *equiv_class_alloc = new_equiv_class_alloc;
+	}
+      mbcset->equiv_classes[mbcset->nequiv_classes++] = idx1;
+    }
+  else
+#endif /* _LIBC */
+    {
+      if (BE (strlen ((const char *) name) != 1, 0))
+	return REG_ECOLLATE;
+      bitset_set (sbcset, *name);
+    }
+  return REG_NOERROR;
+}
+
+  /* Helper function for parse_bracket_exp.
+     Build the character class which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     CHAR_CLASS_ALLOC is the allocated size of mbcset->char_classes,
+     is a pointer argument sinse we may update it.  */
+
+static reg_errcode_t
+#ifdef RE_ENABLE_I18N
+build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
+		 re_charset_t *mbcset, Idx *char_class_alloc,
+		 const unsigned char *class_name, reg_syntax_t syntax)
+#else /* not RE_ENABLE_I18N */
+build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
+		 const unsigned char *class_name, reg_syntax_t syntax)
+#endif /* not RE_ENABLE_I18N */
+{
+  int i;
+  const char *name = (const char *) class_name;
+
+  /* In case of REG_ICASE "upper" and "lower" match the both of
+     upper and lower cases.  */
+  if ((syntax & RE_ICASE)
+      && (strcmp (name, "upper") == 0 || strcmp (name, "lower") == 0))
+    name = "alpha";
+
+#ifdef RE_ENABLE_I18N
+  /* Check the space of the arrays.  */
+  if (BE (*char_class_alloc == mbcset->nchar_classes, 0))
+    {
+      /* Not enough, realloc it.  */
+      /* +1 in case of mbcset->nchar_classes is 0.  */
+      Idx new_char_class_alloc = 2 * mbcset->nchar_classes + 1;
+      /* Use realloc since array is NULL if *alloc == 0.  */
+      wctype_t *new_char_classes = re_realloc (mbcset->char_classes, wctype_t,
+					       new_char_class_alloc);
+      if (BE (new_char_classes == NULL, 0))
+	return REG_ESPACE;
+      mbcset->char_classes = new_char_classes;
+      *char_class_alloc = new_char_class_alloc;
+    }
+  mbcset->char_classes[mbcset->nchar_classes++] = __wctype (name);
+#endif /* RE_ENABLE_I18N */
+
+#define BUILD_CHARCLASS_LOOP(ctype_func)	\
+  do {						\
+    if (BE (trans != NULL, 0))			\
+      {						\
+	for (i = 0; i < SBC_MAX; ++i)		\
+	  if (ctype_func (i))			\
+	    bitset_set (sbcset, trans[i]);	\
+      }						\
+    else					\
+      {						\
+	for (i = 0; i < SBC_MAX; ++i)		\
+	  if (ctype_func (i))			\
+	    bitset_set (sbcset, i);		\
+      }						\
+  } while (0)
+
+  if (strcmp (name, "alnum") == 0)
+    BUILD_CHARCLASS_LOOP (isalnum);
+  else if (strcmp (name, "cntrl") == 0)
+    BUILD_CHARCLASS_LOOP (iscntrl);
+  else if (strcmp (name, "lower") == 0)
+    BUILD_CHARCLASS_LOOP (islower);
+  else if (strcmp (name, "space") == 0)
+    BUILD_CHARCLASS_LOOP (isspace);
+  else if (strcmp (name, "alpha") == 0)
+    BUILD_CHARCLASS_LOOP (isalpha);
+  else if (strcmp (name, "digit") == 0)
+    BUILD_CHARCLASS_LOOP (isdigit);
+  else if (strcmp (name, "print") == 0)
+    BUILD_CHARCLASS_LOOP (isprint);
+  else if (strcmp (name, "upper") == 0)
+    BUILD_CHARCLASS_LOOP (isupper);
+  else if (strcmp (name, "blank") == 0)
+    BUILD_CHARCLASS_LOOP (isblank);
+  else if (strcmp (name, "graph") == 0)
+    BUILD_CHARCLASS_LOOP (isgraph);
+  else if (strcmp (name, "punct") == 0)
+    BUILD_CHARCLASS_LOOP (ispunct);
+  else if (strcmp (name, "xdigit") == 0)
+    BUILD_CHARCLASS_LOOP (isxdigit);
+  else
+    return REG_ECTYPE;
+
+  return REG_NOERROR;
+}
+
+static bin_tree_t *
+build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
+		    const unsigned char *class_name,
+		    const unsigned char *extra, bool non_match,
+		    reg_errcode_t *err)
+{
+  re_bitset_ptr_t sbcset;
+#ifdef RE_ENABLE_I18N
+  re_charset_t *mbcset;
+  Idx alloc = 0;
+#endif /* not RE_ENABLE_I18N */
+  reg_errcode_t ret;
+  re_token_t br_token;
+  bin_tree_t *tree;
+
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+#ifdef RE_ENABLE_I18N
+  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
+#endif /* RE_ENABLE_I18N */
+
+#ifdef RE_ENABLE_I18N
+  if (BE (sbcset == NULL || mbcset == NULL, 0))
+#else /* not RE_ENABLE_I18N */
+  if (BE (sbcset == NULL, 0))
+#endif /* not RE_ENABLE_I18N */
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  if (non_match)
+    {
+#ifdef RE_ENABLE_I18N
+      /*
+      if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
+	bitset_set(cset->sbcset, '\0');
+      */
+      mbcset->non_match = 1;
+#endif /* not RE_ENABLE_I18N */
+    }
+
+  /* We don't care the syntax in this case.  */
+  ret = build_charclass (trans, sbcset,
+#ifdef RE_ENABLE_I18N
+			 mbcset, &alloc,
+#endif /* RE_ENABLE_I18N */
+			 class_name, 0);
+
+  if (BE (ret != REG_NOERROR, 0))
+    {
+      re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+      free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+      *err = ret;
+      return NULL;
+    }
+  /* \w match '_' also.  */
+  for (; *extra; extra++)
+    bitset_set (sbcset, *extra);
+
+  /* If it is non-matching list.  */
+  if (non_match)
+    bitset_not (sbcset);
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure only single byte characters are set.  */
+  if (dfa->mb_cur_max > 1)
+    bitset_mask (sbcset, dfa->sb_char);
+#endif
+
+  /* Build a tree for simple bracket.  */
+  br_token.type = SIMPLE_BRACKET;
+  br_token.opr.sbcset = sbcset;
+  tree = create_token_tree (dfa, NULL, NULL, &br_token);
+  if (BE (tree == NULL, 0))
+    goto build_word_op_espace;
+
+#ifdef RE_ENABLE_I18N
+  if (dfa->mb_cur_max > 1)
+    {
+      bin_tree_t *mbc_tree;
+      /* Build a tree for complex bracket.  */
+      br_token.type = COMPLEX_BRACKET;
+      br_token.opr.mbcset = mbcset;
+      dfa->has_mb_node = 1;
+      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (mbc_tree == NULL, 0))
+	goto build_word_op_espace;
+      /* Then join them by ALT node.  */
+      tree = create_tree (dfa, tree, mbc_tree, OP_ALT);
+      if (BE (mbc_tree != NULL, 1))
+	return tree;
+    }
+  else
+    {
+      free_charset (mbcset);
+      return tree;
+    }
+#else /* not RE_ENABLE_I18N */
+  return tree;
+#endif /* not RE_ENABLE_I18N */
+
+ build_word_op_espace:
+  re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+  free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+  *err = REG_ESPACE;
+  return NULL;
+}
+
+/* This is intended for the expressions like "a{1,3}".
+   Fetch a number from `input', and return the number.
+   Return REG_MISSING if the number field is empty like "{,1}".
+   Return REG_ERROR if an error occurred.  */
+
+static Idx
+fetch_number (re_string_t *input, re_token_t *token, reg_syntax_t syntax)
+{
+  Idx num = REG_MISSING;
+  unsigned char c;
+  while (1)
+    {
+      fetch_token (token, input, syntax);
+      c = token->opr.c;
+      if (BE (token->type == END_OF_RE, 0))
+	return REG_ERROR;
+      if (token->type == OP_CLOSE_DUP_NUM || c == ',')
+	break;
+      num = ((token->type != CHARACTER || c < '0' || '9' < c
+	      || num == REG_ERROR)
+	     ? REG_ERROR
+	     : ((num == REG_MISSING) ? c - '0' : num * 10 + c - '0'));
+      num = (num > RE_DUP_MAX) ? REG_ERROR : num;
+    }
+  return num;
+}
+
+#ifdef RE_ENABLE_I18N
+static void
+free_charset (re_charset_t *cset)
+{
+  re_free (cset->mbchars);
+# ifdef _LIBC
+  re_free (cset->coll_syms);
+  re_free (cset->equiv_classes);
+  re_free (cset->range_starts);
+  re_free (cset->range_ends);
+# endif
+  re_free (cset->char_classes);
+  re_free (cset);
+}
+#endif /* RE_ENABLE_I18N */
+
+/* Functions for binary tree operation.  */
+
+/* Create a tree node.  */
+
+static bin_tree_t *
+create_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
+	     re_token_type_t type)
+{
+  re_token_t t;
+  t.type = type;
+  return create_token_tree (dfa, left, right, &t);
+}
+
+static bin_tree_t *
+create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
+		   const re_token_t *token)
+{
+  bin_tree_t *tree;
+  if (BE (dfa->str_tree_storage_idx == BIN_TREE_STORAGE_SIZE, 0))
+    {
+      bin_tree_storage_t *storage = re_malloc (bin_tree_storage_t, 1);
+
+      if (storage == NULL)
+	return NULL;
+      storage->next = dfa->str_tree_storage;
+      dfa->str_tree_storage = storage;
+      dfa->str_tree_storage_idx = 0;
+    }
+  tree = &dfa->str_tree_storage->data[dfa->str_tree_storage_idx++];
+
+  tree->parent = NULL;
+  tree->left = left;
+  tree->right = right;
+  tree->token = *token;
+  tree->token.duplicated = 0;
+  tree->token.opt_subexp = 0;
+  tree->first = NULL;
+  tree->next = NULL;
+  tree->node_idx = REG_MISSING;
+
+  if (left != NULL)
+    left->parent = tree;
+  if (right != NULL)
+    right->parent = tree;
+  return tree;
+}
+
+/* Mark the tree SRC as an optional subexpression.
+   To be called from preorder or postorder.  */
+
+static reg_errcode_t
+mark_opt_subexp (void *extra, bin_tree_t *node)
+{
+  Idx idx = (Idx) (long) extra;
+  if (node->token.type == SUBEXP && node->token.opr.idx == idx)
+    node->token.opt_subexp = 1;
+
+  return REG_NOERROR;
+}
+
+/* Free the allocated memory inside NODE. */
+
+static void
+free_token (re_token_t *node)
+{
+#ifdef RE_ENABLE_I18N
+  if (node->type == COMPLEX_BRACKET && node->duplicated == 0)
+    free_charset (node->opr.mbcset);
+  else
+#endif /* RE_ENABLE_I18N */
+    if (node->type == SIMPLE_BRACKET && node->duplicated == 0)
+      re_free (node->opr.sbcset);
+}
+
+/* Worker function for tree walking.  Free the allocated memory inside NODE
+   and its children. */
+
+static reg_errcode_t
+free_tree (void *extra, bin_tree_t *node)
+{
+  free_token (&node->token);
+  return REG_NOERROR;
+}
+
+
+/* Duplicate the node SRC, and return new node.  This is a preorder
+   visit similar to the one implemented by the generic visitor, but
+   we need more infrastructure to maintain two parallel trees --- so,
+   it's easier to duplicate.  */
+
+static bin_tree_t *
+duplicate_tree (const bin_tree_t *root, re_dfa_t *dfa)
+{
+  const bin_tree_t *node;
+  bin_tree_t *dup_root;
+  bin_tree_t **p_new = &dup_root, *dup_node = root->parent;
+
+  for (node = root; ; )
+    {
+      /* Create a new tree and link it back to the current parent.  */
+      *p_new = create_token_tree (dfa, NULL, NULL, &node->token);
+      if (*p_new == NULL)
+	return NULL;
+      (*p_new)->parent = dup_node;
+      (*p_new)->token.duplicated = 1;
+      dup_node = *p_new;
+
+      /* Go to the left node, or up and to the right.  */
+      if (node->left)
+	{
+	  node = node->left;
+	  p_new = &dup_node->left;
+	}
+      else
+	{
+	  const bin_tree_t *prev = NULL;
+	  while (node->right == prev || node->right == NULL)
+	    {
+	      prev = node;
+	      node = node->parent;
+	      dup_node = dup_node->parent;
+	      if (!node)
+	        return dup_root;
+	    }
+	  node = node->right;
+	  p_new = &dup_node->right;
+	}
+    }
+}
diff --git a/src/bin/m4/lib/regex.c b/src/bin/m4/lib/regex.c
new file mode 100644
index 0000000000..d4eb726b29
--- /dev/null
+++ b/src/bin/m4/lib/regex.c
@@ -0,0 +1,71 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#include <config.h>
+
+/* Make sure noone compiles this code with a C++ compiler.  */
+#if defined __cplusplus && defined _LIBC
+# error "This is C code, use a C compiler"
+#endif
+
+#ifdef _LIBC
+/* We have to keep the namespace clean.  */
+# define regfree(preg) __regfree (preg)
+# define regexec(pr, st, nm, pm, ef) __regexec (pr, st, nm, pm, ef)
+# define regcomp(preg, pattern, cflags) __regcomp (preg, pattern, cflags)
+# define regerror(errcode, preg, errbuf, errbuf_size) \
+	__regerror(errcode, preg, errbuf, errbuf_size)
+# define re_set_registers(bu, re, nu, st, en) \
+	__re_set_registers (bu, re, nu, st, en)
+# define re_match_2(bufp, string1, size1, string2, size2, pos, regs, stop) \
+	__re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
+# define re_match(bufp, string, size, pos, regs) \
+	__re_match (bufp, string, size, pos, regs)
+# define re_search(bufp, string, size, startpos, range, regs) \
+	__re_search (bufp, string, size, startpos, range, regs)
+# define re_compile_pattern(pattern, length, bufp) \
+	__re_compile_pattern (pattern, length, bufp)
+# define re_set_syntax(syntax) __re_set_syntax (syntax)
+# define re_search_2(bufp, st1, s1, st2, s2, startpos, range, regs, stop) \
+	__re_search_2 (bufp, st1, s1, st2, s2, startpos, range, regs, stop)
+# define re_compile_fastmap(bufp) __re_compile_fastmap (bufp)
+
+# include "../locale/localeinfo.h"
+#endif
+
+/* On some systems, limits.h sets RE_DUP_MAX to a lower value than
+   GNU regex allows.  Include it before <regex.h>, which correctly
+   #undefs RE_DUP_MAX and sets it to the right value.  */
+#include <limits.h>
+
+#include <regex.h>
+#include "regex_internal.h"
+
+#include "regex_internal.c"
+#include "regcomp.c"
+#include "regexec.c"
+
+/* Binary backward compatibility.  */
+#if _LIBC
+# include <shlib-compat.h>
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3)
+link_warning (re_max_failures, "the 're_max_failures' variable is obsolete and will go away.")
+int re_max_failures = 2000;
+# endif
+#endif
diff --git a/src/bin/m4/lib/regex.h b/src/bin/m4/lib/regex.h
new file mode 100644
index 0000000000..e8748e195b
--- /dev/null
+++ b/src/bin/m4/lib/regex.h
@@ -0,0 +1,668 @@
+/* Definitions for data structures and routines for the regular
+   expression library.
+   Copyright (C) 1985,1989-93,1995-98,2000,2001,2002,2003,2005,2006
+   Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#ifndef _REGEX_H
+#define _REGEX_H 1
+
+#include <sys/types.h>
+
+/* Allow the use in C++ code.  */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Define __USE_GNU_REGEX to declare GNU extensions that violate the
+   POSIX name space rules.  */
+#undef __USE_GNU_REGEX
+#if (defined _GNU_SOURCE					\
+     || (!defined _POSIX_C_SOURCE && !defined _POSIX_SOURCE	\
+	 && !defined _XOPEN_SOURCE))
+# define __USE_GNU_REGEX 1
+#endif
+
+#ifdef _REGEX_LARGE_OFFSETS
+
+/* Use types and values that are wide enough to represent signed and
+   unsigned byte offsets in memory.  This currently works only when
+   the regex code is used outside of the GNU C library; it is not yet
+   supported within glibc itself, and glibc users should not define
+   _REGEX_LARGE_OFFSETS.  */
+
+/* The type of the offset of a byte within a string.
+   For historical reasons POSIX 1003.1-2004 requires that regoff_t be
+   at least as wide as off_t.  However, many common POSIX platforms set
+   regoff_t to the more-sensible ssize_t and the Open Group has
+   signalled its intention to change the requirement to be that
+   regoff_t be at least as wide as ptrdiff_t and ssize_t; see XBD ERN
+   60 (2005-08-25).  We don't know of any hosts where ssize_t or
+   ptrdiff_t is wider than ssize_t, so ssize_t is safe.  */
+typedef ssize_t regoff_t;
+
+/* The type of nonnegative object indexes.  Traditionally, GNU regex
+   uses 'int' for these.  Code that uses __re_idx_t should work
+   regardless of whether the type is signed.  */
+typedef size_t __re_idx_t;
+
+/* The type of object sizes.  */
+typedef size_t __re_size_t;
+
+/* The type of object sizes, in places where the traditional code
+   uses unsigned long int.  */
+typedef size_t __re_long_size_t;
+
+#else
+
+/* Use types that are binary-compatible with the traditional GNU regex
+   implementation, which mishandles strings longer than INT_MAX.  */
+
+typedef int regoff_t;
+typedef int __re_idx_t;
+typedef unsigned int __re_size_t;
+typedef unsigned long int __re_long_size_t;
+
+#endif
+
+/* The following two types have to be signed and unsigned integer type
+   wide enough to hold a value of a pointer.  For most ANSI compilers
+   ptrdiff_t and size_t should be likely OK.  Still size of these two
+   types is 2 for Microsoft C.  Ugh... */
+typedef long int s_reg_t;
+typedef unsigned long int active_reg_t;
+
+/* The following bits are used to determine the regexp syntax we
+   recognize.  The set/not-set meanings are chosen so that Emacs syntax
+   remains the value 0.  The bits are given in alphabetical order, and
+   the definitions shifted by one from the previous bit; thus, when we
+   add or remove a bit, only one other definition need change.  */
+typedef unsigned long int reg_syntax_t;
+
+#ifdef __USE_GNU_REGEX
+
+/* If this bit is not set, then \ inside a bracket expression is literal.
+   If set, then such a \ quotes the following character.  */
+# define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
+
+/* If this bit is not set, then + and ? are operators, and \+ and \? are
+     literals.
+   If set, then \+ and \? are operators and + and ? are literals.  */
+# define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
+
+/* If this bit is set, then character classes are supported.  They are:
+     [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
+     [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
+   If not set, then character classes are not supported.  */
+# define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
+
+/* If this bit is set, then ^ and $ are always anchors (outside bracket
+     expressions, of course).
+   If this bit is not set, then it depends:
+        ^  is an anchor if it is at the beginning of a regular
+           expression or after an open-group or an alternation operator;
+        $  is an anchor if it is at the end of a regular expression, or
+           before a close-group or an alternation operator.
+
+   This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
+   POSIX draft 11.2 says that * etc. in leading positions is undefined.
+   We already implemented a previous draft which made those constructs
+   invalid, though, so we haven't changed the code back.  */
+# define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
+
+/* If this bit is set, then special characters are always special
+     regardless of where they are in the pattern.
+   If this bit is not set, then special characters are special only in
+     some contexts; otherwise they are ordinary.  Specifically,
+     * + ? and intervals are only special when not after the beginning,
+     open-group, or alternation operator.  */
+# define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
+
+/* If this bit is set, then *, +, ?, and { cannot be first in an re or
+     immediately after an alternation or begin-group operator.  */
+# define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
+
+/* If this bit is set, then . matches newline.
+   If not set, then it doesn't.  */
+# define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
+
+/* If this bit is set, then . doesn't match NUL.
+   If not set, then it does.  */
+# define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
+
+/* If this bit is set, nonmatching lists [^...] do not match newline.
+   If not set, they do.  */
+# define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
+
+/* If this bit is set, either \{...\} or {...} defines an
+     interval, depending on RE_NO_BK_BRACES.
+   If not set, \{, \}, {, and } are literals.  */
+# define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
+
+/* If this bit is set, +, ? and | aren't recognized as operators.
+   If not set, they are.  */
+# define RE_LIMITED_OPS (RE_INTERVALS << 1)
+
+/* If this bit is set, newline is an alternation operator.
+   If not set, newline is literal.  */
+# define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
+
+/* If this bit is set, then `{...}' defines an interval, and \{ and \}
+     are literals.
+  If not set, then `\{...\}' defines an interval.  */
+# define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
+
+/* If this bit is set, (...) defines a group, and \( and \) are literals.
+   If not set, \(...\) defines a group, and ( and ) are literals.  */
+# define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
+
+/* If this bit is set, then \<digit> matches <digit>.
+   If not set, then \<digit> is a back-reference.  */
+# define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
+
+/* If this bit is set, then | is an alternation operator, and \| is literal.
+   If not set, then \| is an alternation operator, and | is literal.  */
+# define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
+
+/* If this bit is set, then an ending range point collating higher
+     than the starting range point, as in [z-a], is invalid.
+   If not set, then when ending range point collates higher than the
+     starting range point, the range is ignored.  */
+# define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
+
+/* If this bit is set, then an unmatched ) is ordinary.
+   If not set, then an unmatched ) is invalid.  */
+# define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
+
+/* If this bit is set, succeed as soon as we match the whole pattern,
+   without further backtracking.  */
+# define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
+
+/* If this bit is set, do not process the GNU regex operators.
+   If not set, then the GNU regex operators are recognized. */
+# define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
+
+/* If this bit is set, turn on internal regex debugging.
+   If not set, and debugging was on, turn it off.
+   This only works if regex.c is compiled -DDEBUG.
+   We define this bit always, so that all that's needed to turn on
+   debugging is to recompile regex.c; the calling code can always have
+   this bit set, and it won't affect anything in the normal case. */
+# define RE_DEBUG (RE_NO_GNU_OPS << 1)
+
+/* If this bit is set, a syntactically invalid interval is treated as
+   a string of ordinary characters.  For example, the ERE 'a{1' is
+   treated as 'a\{1'.  */
+# define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
+
+/* If this bit is set, then ignore case when matching.
+   If not set, then case is significant.  */
+# define RE_ICASE (RE_INVALID_INTERVAL_ORD << 1)
+
+/* This bit is used internally like RE_CONTEXT_INDEP_ANCHORS but only
+   for ^, because it is difficult to scan the regex backwards to find
+   whether ^ should be special.  */
+# define RE_CARET_ANCHORS_HERE (RE_ICASE << 1)
+
+/* If this bit is set, then \{ cannot be first in an bre or
+   immediately after an alternation or begin-group operator.  */
+# define RE_CONTEXT_INVALID_DUP (RE_CARET_ANCHORS_HERE << 1)
+
+/* If this bit is set, then no_sub will be set to 1 during
+   re_compile_pattern.  */
+# define RE_NO_SUB (RE_CONTEXT_INVALID_DUP << 1)
+
+#endif /* defined __USE_GNU_REGEX */
+
+/* This global variable defines the particular regexp syntax to use (for
+   some interfaces).  When a regexp is compiled, the syntax used is
+   stored in the pattern buffer, so changing this does not affect
+   already-compiled regexps.  */
+extern reg_syntax_t re_syntax_options;
+
+#ifdef __USE_GNU_REGEX
+/* Define combinations of the above bits for the standard possibilities.
+   (The [[[ comments delimit what gets put into the Texinfo file, so
+   don't delete them!)  */
+/* [[[begin syntaxes]]] */
+# define RE_SYNTAX_EMACS 0
+
+# define RE_SYNTAX_AWK							\
+  (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL			\
+   | RE_NO_BK_PARENS              | RE_NO_BK_REFS			\
+   | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES			\
+   | RE_DOT_NEWLINE		  | RE_CONTEXT_INDEP_ANCHORS		\
+   | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
+
+# define RE_SYNTAX_GNU_AWK						\
+  ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG)	\
+   & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS		\
+       | RE_CONTEXT_INVALID_OPS ))
+
+# define RE_SYNTAX_POSIX_AWK						\
+  (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS		\
+   | RE_INTERVALS	    | RE_NO_GNU_OPS)
+
+# define RE_SYNTAX_GREP							\
+  (RE_BK_PLUS_QM              | RE_CHAR_CLASSES				\
+   | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS				\
+   | RE_NEWLINE_ALT)
+
+# define RE_SYNTAX_EGREP						\
+  (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS			\
+   | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE			\
+   | RE_NEWLINE_ALT       | RE_NO_BK_PARENS				\
+   | RE_NO_BK_VBAR)
+
+# define RE_SYNTAX_POSIX_EGREP						\
+  (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES			\
+   | RE_INVALID_INTERVAL_ORD)
+
+/* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
+# define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
+
+# define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
+
+/* Syntax bits common to both basic and extended POSIX regex syntax.  */
+# define _RE_SYNTAX_POSIX_COMMON					\
+  (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL		\
+   | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
+
+# define RE_SYNTAX_POSIX_BASIC						\
+  (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM | RE_CONTEXT_INVALID_DUP)
+
+/* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
+   RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
+   isn't minimal, since other operators, such as \`, aren't disabled.  */
+# define RE_SYNTAX_POSIX_MINIMAL_BASIC					\
+  (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
+
+# define RE_SYNTAX_POSIX_EXTENDED					\
+  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS			\
+   | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES				\
+   | RE_NO_BK_PARENS        | RE_NO_BK_VBAR				\
+   | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
+
+/* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
+   removed and RE_NO_BK_REFS is added.  */
+# define RE_SYNTAX_POSIX_MINIMAL_EXTENDED				\
+  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS			\
+   | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES				\
+   | RE_NO_BK_PARENS        | RE_NO_BK_REFS				\
+   | RE_NO_BK_VBAR	    | RE_UNMATCHED_RIGHT_PAREN_ORD)
+/* [[[end syntaxes]]] */
+
+#endif /* defined __USE_GNU_REGEX */
+
+#ifdef __USE_GNU_REGEX
+
+/* Maximum number of duplicates an interval can allow.  POSIX-conforming
+   systems might define this in <limits.h>, but we want our
+   value, so remove any previous define.  */
+# ifdef RE_DUP_MAX
+#  undef RE_DUP_MAX
+# endif
+
+/* RE_DUP_MAX is 2**15 - 1 because an earlier implementation stored
+   the counter as a 2-byte signed integer.  This is no longer true, so
+   RE_DUP_MAX could be increased to (INT_MAX / 10 - 1), or to
+   ((SIZE_MAX - 2) / 10 - 1) if _REGEX_LARGE_OFFSETS is defined.
+   However, there would be a huge performance problem if someone
+   actually used a pattern like a\{214748363\}, so RE_DUP_MAX retains
+   its historical value.  */
+# define RE_DUP_MAX (0x7fff)
+
+#endif /* defined __USE_GNU_REGEX */
+
+
+/* POSIX `cflags' bits (i.e., information for `regcomp').  */
+
+/* If this bit is set, then use extended regular expression syntax.
+   If not set, then use basic regular expression syntax.  */
+#define REG_EXTENDED 1
+
+/* If this bit is set, then ignore case when matching.
+   If not set, then case is significant.  */
+#define REG_ICASE (1 << 1)
+
+/* If this bit is set, then anchors do not match at newline
+     characters in the string.
+   If not set, then anchors do match at newlines.  */
+#define REG_NEWLINE (1 << 2)
+
+/* If this bit is set, then report only success or fail in regexec.
+   If not set, then returns differ between not matching and errors.  */
+#define REG_NOSUB (1 << 3)
+
+
+/* POSIX `eflags' bits (i.e., information for regexec).  */
+
+/* If this bit is set, then the beginning-of-line operator doesn't match
+     the beginning of the string (presumably because it's not the
+     beginning of a line).
+   If not set, then the beginning-of-line operator does match the
+     beginning of the string.  */
+#define REG_NOTBOL 1
+
+/* Like REG_NOTBOL, except for the end-of-line.  */
+#define REG_NOTEOL (1 << 1)
+
+/* Use PMATCH[0] to delimit the start and end of the search in the
+   buffer.  */
+#define REG_STARTEND (1 << 2)
+
+
+/* If any error codes are removed, changed, or added, update the
+   `__re_error_msgid' table in regcomp.c.  */
+
+typedef enum
+{
+  _REG_ENOSYS = -1,	/* This will never happen for this implementation.  */
+  _REG_NOERROR = 0,	/* Success.  */
+  _REG_NOMATCH,		/* Didn't find a match (for regexec).  */
+
+  /* POSIX regcomp return error codes.  (In the order listed in the
+     standard.)  */
+  _REG_BADPAT,		/* Invalid pattern.  */
+  _REG_ECOLLATE,	/* Invalid collating element.  */
+  _REG_ECTYPE,		/* Invalid character class name.  */
+  _REG_EESCAPE,		/* Trailing backslash.  */
+  _REG_ESUBREG,		/* Invalid back reference.  */
+  _REG_EBRACK,		/* Unmatched left bracket.  */
+  _REG_EPAREN,		/* Parenthesis imbalance.  */
+  _REG_EBRACE,		/* Unmatched \{.  */
+  _REG_BADBR,		/* Invalid contents of \{\}.  */
+  _REG_ERANGE,		/* Invalid range end.  */
+  _REG_ESPACE,		/* Ran out of memory.  */
+  _REG_BADRPT,		/* No preceding re for repetition op.  */
+
+  /* Error codes we've added.  */
+  _REG_EEND,		/* Premature end.  */
+  _REG_ESIZE,		/* Compiled pattern bigger than 2^16 bytes.  */
+  _REG_ERPAREN		/* Unmatched ) or \); not returned from regcomp.  */
+} reg_errcode_t;
+
+#ifdef _XOPEN_SOURCE
+# define REG_ENOSYS	_REG_ENOSYS
+#endif
+#define REG_NOERROR	_REG_NOERROR
+#define REG_NOMATCH	_REG_NOMATCH
+#define REG_BADPAT	_REG_BADPAT
+#define REG_ECOLLATE	_REG_ECOLLATE
+#define REG_ECTYPE	_REG_ECTYPE
+#define REG_EESCAPE	_REG_EESCAPE
+#define REG_ESUBREG	_REG_ESUBREG
+#define REG_EBRACK	_REG_EBRACK
+#define REG_EPAREN	_REG_EPAREN
+#define REG_EBRACE	_REG_EBRACE
+#define REG_BADBR	_REG_BADBR
+#define REG_ERANGE	_REG_ERANGE
+#define REG_ESPACE	_REG_ESPACE
+#define REG_BADRPT	_REG_BADRPT
+#define REG_EEND	_REG_EEND
+#define REG_ESIZE	_REG_ESIZE
+#define REG_ERPAREN	_REG_ERPAREN
+
+/* struct re_pattern_buffer normally uses member names like `buffer'
+   that POSIX does not allow.  In POSIX mode these members have names
+   with leading `re_' (e.g., `re_buffer').  */
+#ifdef __USE_GNU_REGEX
+# define _REG_RE_NAME(id) id
+# define _REG_RM_NAME(id) id
+#else
+# define _REG_RE_NAME(id) re_##id
+# define _REG_RM_NAME(id) rm_##id
+#endif
+
+/* The user can specify the type of the re_translate member by
+   defining the macro RE_TRANSLATE_TYPE, which defaults to unsigned
+   char *.  This pollutes the POSIX name space, so in POSIX mode just
+   use unsigned char *.  */
+#ifdef __USE_GNU_REGEX
+# ifndef RE_TRANSLATE_TYPE
+#  define RE_TRANSLATE_TYPE unsigned char *
+# endif
+# define REG_TRANSLATE_TYPE RE_TRANSLATE_TYPE
+#else
+# define REG_TRANSLATE_TYPE unsigned char *
+#endif
+
+/* This data structure represents a compiled pattern.  Before calling
+   the pattern compiler, the fields `buffer', `allocated', `fastmap',
+   `translate', and `no_sub' can be set.  After the pattern has been
+   compiled, the `re_nsub' field is available.  All other fields are
+   private to the regex routines.  */
+
+struct re_pattern_buffer
+{
+  /* Space that holds the compiled pattern.  It is declared as
+     `unsigned char *' because its elements are sometimes used as
+     array indexes.  */
+  unsigned char *_REG_RE_NAME (buffer);
+
+  /* Number of bytes to which `buffer' points.  */
+  __re_long_size_t _REG_RE_NAME (allocated);
+
+  /* Number of bytes actually used in `buffer'.  */
+  __re_long_size_t _REG_RE_NAME (used);
+
+  /* Syntax setting with which the pattern was compiled.  */
+  reg_syntax_t _REG_RE_NAME (syntax);
+
+  /* Pointer to a fastmap, if any, otherwise zero.  re_search uses the
+     fastmap, if there is one, to skip over impossible starting points
+     for matches.  */
+  char *_REG_RE_NAME (fastmap);
+
+  /* Either a translate table to apply to all characters before
+     comparing them, or zero for no translation.  The translation is
+     applied to a pattern when it is compiled and to a string when it
+     is matched.  */
+  REG_TRANSLATE_TYPE _REG_RE_NAME (translate);
+
+  /* Number of subexpressions found by the compiler.  */
+  size_t re_nsub;
+
+  /* Zero if this pattern cannot match the empty string, one else.
+     Well, in truth it's used only in `re_search_2', to see whether or
+     not we should use the fastmap, so we don't set this absolutely
+     perfectly; see `re_compile_fastmap' (the `duplicate' case).  */
+  unsigned int _REG_RE_NAME (can_be_null) : 1;
+
+  /* If REGS_UNALLOCATED, allocate space in the `regs' structure
+     for `max (RE_NREGS, re_nsub + 1)' groups.
+     If REGS_REALLOCATE, reallocate space if necessary.
+     If REGS_FIXED, use what's there.  */
+#ifdef __USE_GNU_REGEX
+# define REGS_UNALLOCATED 0
+# define REGS_REALLOCATE 1
+# define REGS_FIXED 2
+#endif
+  unsigned int _REG_RE_NAME (regs_allocated) : 2;
+
+  /* Set to zero when `regex_compile' compiles a pattern; set to one
+     by `re_compile_fastmap' if it updates the fastmap.  */
+  unsigned int _REG_RE_NAME (fastmap_accurate) : 1;
+
+  /* If set, `re_match_2' does not return information about
+     subexpressions.  */
+  unsigned int _REG_RE_NAME (no_sub) : 1;
+
+  /* If set, a beginning-of-line anchor doesn't match at the beginning
+     of the string.  */
+  unsigned int _REG_RE_NAME (not_bol) : 1;
+
+  /* Similarly for an end-of-line anchor.  */
+  unsigned int _REG_RE_NAME (not_eol) : 1;
+
+  /* If true, an anchor at a newline matches.  */
+  unsigned int _REG_RE_NAME (newline_anchor) : 1;
+
+/* [[[end pattern_buffer]]] */
+};
+
+typedef struct re_pattern_buffer regex_t;
+
+/* This is the structure we store register match data in.  See
+   regex.texinfo for a full description of what registers match.  */
+struct re_registers
+{
+  __re_size_t _REG_RM_NAME (num_regs);
+  regoff_t *_REG_RM_NAME (start);
+  regoff_t *_REG_RM_NAME (end);
+};
+
+
+/* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
+   `re_match_2' returns information about at least this many registers
+   the first time a `regs' structure is passed.  */
+#if !defined RE_NREGS && defined __USE_GNU_REGEX
+# define RE_NREGS 30
+#endif
+
+
+/* POSIX specification for registers.  Aside from the different names than
+   `re_registers', POSIX uses an array of structures, instead of a
+   structure of arrays.  */
+typedef struct
+{
+  regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
+  regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
+} regmatch_t;
+
+/* Declarations for routines.  */
+
+/* Sets the current default syntax to SYNTAX, and return the old syntax.
+   You can also simply assign to the `re_syntax_options' variable.  */
+extern reg_syntax_t re_set_syntax (reg_syntax_t __syntax);
+
+/* Compile the regular expression PATTERN, with length LENGTH
+   and syntax given by the global `re_syntax_options', into the buffer
+   BUFFER.  Return NULL if successful, and an error string if not.  */
+extern const char *re_compile_pattern (const char *__pattern, size_t __length,
+				       struct re_pattern_buffer *__buffer);
+
+
+/* Compile a fastmap for the compiled pattern in BUFFER; used to
+   accelerate searches.  Return 0 if successful and -2 if was an
+   internal error.  */
+extern int re_compile_fastmap (struct re_pattern_buffer *__buffer);
+
+
+/* Search in the string STRING (with length LENGTH) for the pattern
+   compiled into BUFFER.  Start searching at position START, for RANGE
+   characters.  Return the starting position of the match, -1 for no
+   match, or -2 for an internal error.  Also return register
+   information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
+extern regoff_t re_search (struct re_pattern_buffer *__buffer,
+			   const char *__string, __re_idx_t __length,
+			   __re_idx_t __start, regoff_t __range,
+			   struct re_registers *__regs);
+
+
+/* Like `re_search', but search in the concatenation of STRING1 and
+   STRING2.  Also, stop searching at index START + STOP.  */
+extern regoff_t re_search_2 (struct re_pattern_buffer *__buffer,
+			     const char *__string1, __re_idx_t __length1,
+			     const char *__string2, __re_idx_t __length2,
+			     __re_idx_t __start, regoff_t __range,
+			     struct re_registers *__regs,
+			     __re_idx_t __stop);
+
+
+/* Like `re_search', but return how many characters in STRING the regexp
+   in BUFFER matched, starting at position START.  */
+extern regoff_t re_match (struct re_pattern_buffer *__buffer,
+			  const char *__string, __re_idx_t __length,
+			  __re_idx_t __start, struct re_registers *__regs);
+
+
+/* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
+extern regoff_t re_match_2 (struct re_pattern_buffer *__buffer,
+			    const char *__string1, __re_idx_t __length1,
+			    const char *__string2, __re_idx_t __length2,
+			    __re_idx_t __start, struct re_registers *__regs,
+			    __re_idx_t __stop);
+
+
+/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+   ENDS.  Subsequent matches using BUFFER and REGS will use this memory
+   for recording register information.  STARTS and ENDS must be
+   allocated with malloc, and must each be at least `NUM_REGS * sizeof
+   (regoff_t)' bytes long.
+
+   If NUM_REGS == 0, then subsequent matches should allocate their own
+   register data.
+
+   Unless this function is called, the first search or match using
+   PATTERN_BUFFER will allocate its own register data, without
+   freeing the old data.  */
+extern void re_set_registers (struct re_pattern_buffer *__buffer,
+			      struct re_registers *__regs,
+			      __re_size_t __num_regs,
+			      regoff_t *__starts, regoff_t *__ends);
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+# ifndef _CRAY
+/* 4.2 bsd compatibility.  */
+extern char *re_comp (const char *);
+extern int re_exec (const char *);
+# endif
+#endif
+
+/* GCC 2.95 and later have "__restrict"; C99 compilers have
+   "restrict", and "configure" may have defined "restrict".  */
+#ifndef __restrict
+# if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
+#  if defined restrict || 199901L <= __STDC_VERSION__
+#   define __restrict restrict
+#  else
+#   define __restrict
+#  endif
+# endif
+#endif
+/* gcc 3.1 and up support the [restrict] syntax.  */
+#ifndef __restrict_arr
+# if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)) \
+     && !defined __GNUG__
+#  define __restrict_arr __restrict
+# else
+#  define __restrict_arr
+# endif
+#endif
+
+/* POSIX compatibility.  */
+extern int regcomp (regex_t *__restrict __preg,
+		    const char *__restrict __pattern,
+		    int __cflags);
+
+extern int regexec (const regex_t *__restrict __preg,
+		    const char *__restrict __string, size_t __nmatch,
+		    regmatch_t __pmatch[__restrict_arr],
+		    int __eflags);
+
+extern size_t regerror (int __errcode, const regex_t *__restrict __preg,
+			char *__restrict __errbuf, size_t __errbuf_size);
+
+extern void regfree (regex_t *__preg);
+
+
+#ifdef __cplusplus
+}
+#endif	/* C++ */
+
+#endif /* regex.h */
diff --git a/src/bin/m4/lib/regex_internal.c b/src/bin/m4/lib/regex_internal.c
new file mode 100644
index 0000000000..78e16f3301
--- /dev/null
+++ b/src/bin/m4/lib/regex_internal.c
@@ -0,0 +1,1742 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+static void re_string_construct_common (const char *str, Idx len,
+					re_string_t *pstr,
+					RE_TRANSLATE_TYPE trans, bool icase,
+					const re_dfa_t *dfa) internal_function;
+static re_dfastate_t *create_ci_newstate (const re_dfa_t *dfa,
+					  const re_node_set *nodes,
+					  re_hashval_t hash) internal_function;
+static re_dfastate_t *create_cd_newstate (const re_dfa_t *dfa,
+					  const re_node_set *nodes,
+					  unsigned int context,
+					  re_hashval_t hash) internal_function;
+
+/* Functions for string operation.  */
+
+/* This function allocate the buffers.  It is necessary to call
+   re_string_reconstruct before using the object.  */
+
+static reg_errcode_t
+internal_function
+re_string_allocate (re_string_t *pstr, const char *str, Idx len, Idx init_len,
+		    RE_TRANSLATE_TYPE trans, bool icase, const re_dfa_t *dfa)
+{
+  reg_errcode_t ret;
+  Idx init_buf_len;
+
+  /* Ensure at least one character fits into the buffers.  */
+  if (init_len < dfa->mb_cur_max)
+    init_len = dfa->mb_cur_max;
+  init_buf_len = (len + 1 < init_len) ? len + 1: init_len;
+  re_string_construct_common (str, len, pstr, trans, icase, dfa);
+
+  ret = re_string_realloc_buffers (pstr, init_buf_len);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  pstr->word_char = dfa->word_char;
+  pstr->word_ops_used = dfa->word_ops_used;
+  pstr->mbs = pstr->mbs_allocated ? pstr->mbs : (unsigned char *) str;
+  pstr->valid_len = (pstr->mbs_allocated || dfa->mb_cur_max > 1) ? 0 : len;
+  pstr->valid_raw_len = pstr->valid_len;
+  return REG_NOERROR;
+}
+
+/* This function allocate the buffers, and initialize them.  */
+
+static reg_errcode_t
+internal_function
+re_string_construct (re_string_t *pstr, const char *str, Idx len,
+		     RE_TRANSLATE_TYPE trans, bool icase, const re_dfa_t *dfa)
+{
+  reg_errcode_t ret;
+  memset (pstr, '\0', sizeof (re_string_t));
+  re_string_construct_common (str, len, pstr, trans, icase, dfa);
+
+  if (len > 0)
+    {
+      ret = re_string_realloc_buffers (pstr, len + 1);
+      if (BE (ret != REG_NOERROR, 0))
+	return ret;
+    }
+  pstr->mbs = pstr->mbs_allocated ? pstr->mbs : (unsigned char *) str;
+
+  if (icase)
+    {
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+	{
+	  while (1)
+	    {
+	      ret = build_wcs_upper_buffer (pstr);
+	      if (BE (ret != REG_NOERROR, 0))
+		return ret;
+	      if (pstr->valid_raw_len >= len)
+		break;
+	      if (pstr->bufs_len > pstr->valid_len + dfa->mb_cur_max)
+		break;
+	      ret = re_string_realloc_buffers (pstr, pstr->bufs_len * 2);
+	      if (BE (ret != REG_NOERROR, 0))
+		return ret;
+	    }
+	}
+      else
+#endif /* RE_ENABLE_I18N  */
+	build_upper_buffer (pstr);
+    }
+  else
+    {
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+	build_wcs_buffer (pstr);
+      else
+#endif /* RE_ENABLE_I18N  */
+	{
+	  if (trans != NULL)
+	    re_string_translate_buffer (pstr);
+	  else
+	    {
+	      pstr->valid_len = pstr->bufs_len;
+	      pstr->valid_raw_len = pstr->bufs_len;
+	    }
+	}
+    }
+
+  return REG_NOERROR;
+}
+
+/* Helper functions for re_string_allocate, and re_string_construct.  */
+
+static reg_errcode_t
+internal_function
+re_string_realloc_buffers (re_string_t *pstr, Idx new_buf_len)
+{
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1)
+    {
+      wint_t *new_wcs;
+
+      /* Avoid overflow.  */
+      size_t max_object_size = MAX (sizeof (wint_t), sizeof (Idx));
+      if (BE (SIZE_MAX / max_object_size < new_buf_len, 0))
+	return REG_ESPACE;
+
+      new_wcs = re_realloc (pstr->wcs, wint_t, new_buf_len);
+      if (BE (new_wcs == NULL, 0))
+	return REG_ESPACE;
+      pstr->wcs = new_wcs;
+      if (pstr->offsets != NULL)
+	{
+	  Idx *new_offsets = re_realloc (pstr->offsets, Idx, new_buf_len);
+	  if (BE (new_offsets == NULL, 0))
+	    return REG_ESPACE;
+	  pstr->offsets = new_offsets;
+	}
+    }
+#endif /* RE_ENABLE_I18N  */
+  if (pstr->mbs_allocated)
+    {
+      unsigned char *new_mbs = re_realloc (pstr->mbs, unsigned char,
+					   new_buf_len);
+      if (BE (new_mbs == NULL, 0))
+	return REG_ESPACE;
+      pstr->mbs = new_mbs;
+    }
+  pstr->bufs_len = new_buf_len;
+  return REG_NOERROR;
+}
+
+
+static void
+internal_function
+re_string_construct_common (const char *str, Idx len, re_string_t *pstr,
+			    RE_TRANSLATE_TYPE trans, bool icase,
+			    const re_dfa_t *dfa)
+{
+  pstr->raw_mbs = (const unsigned char *) str;
+  pstr->len = len;
+  pstr->raw_len = len;
+  pstr->trans = trans;
+  pstr->icase = icase;
+  pstr->mbs_allocated = (trans != NULL || icase);
+  pstr->mb_cur_max = dfa->mb_cur_max;
+  pstr->is_utf8 = dfa->is_utf8;
+  pstr->map_notascii = dfa->map_notascii;
+  pstr->stop = pstr->len;
+  pstr->raw_stop = pstr->stop;
+}
+
+#ifdef RE_ENABLE_I18N
+
+/* Build wide character buffer PSTR->WCS.
+   If the byte sequence of the string are:
+     <mb1>(0), <mb1>(1), <mb2>(0), <mb2>(1), <sb3>
+   Then wide character buffer will be:
+     <wc1>   , WEOF    , <wc2>   , WEOF    , <wc3>
+   We use WEOF for padding, they indicate that the position isn't
+   a first byte of a multibyte character.
+
+   Note that this function assumes PSTR->VALID_LEN elements are already
+   built and starts from PSTR->VALID_LEN.  */
+
+static void
+internal_function
+build_wcs_buffer (re_string_t *pstr)
+{
+#ifdef _LIBC
+  unsigned char buf[MB_LEN_MAX];
+  assert (MB_LEN_MAX >= pstr->mb_cur_max);
+#else
+  unsigned char buf[64];
+#endif
+  mbstate_t prev_st;
+  Idx byte_idx, end_idx, remain_len;
+  size_t mbclen;
+
+  /* Build the buffers from pstr->valid_len to either pstr->len or
+     pstr->bufs_len.  */
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+  for (byte_idx = pstr->valid_len; byte_idx < end_idx;)
+    {
+      wchar_t wc;
+      const char *p;
+
+      remain_len = end_idx - byte_idx;
+      prev_st = pstr->cur_state;
+      /* Apply the translation if we need.  */
+      if (BE (pstr->trans != NULL, 0))
+	{
+	  int i, ch;
+
+	  for (i = 0; i < pstr->mb_cur_max && i < remain_len; ++i)
+	    {
+	      ch = pstr->raw_mbs [pstr->raw_mbs_idx + byte_idx + i];
+	      buf[i] = pstr->mbs[byte_idx + i] = pstr->trans[ch];
+	    }
+	  p = (const char *) buf;
+	}
+      else
+	p = (const char *) pstr->raw_mbs + pstr->raw_mbs_idx + byte_idx;
+      mbclen = mbrtowc (&wc, p, remain_len, &pstr->cur_state);
+      if (BE (mbclen == (size_t) -2, 0))
+	{
+	  /* The buffer doesn't have enough space, finish to build.  */
+	  pstr->cur_state = prev_st;
+	  break;
+	}
+      else if (BE (mbclen == (size_t) -1 || mbclen == 0, 0))
+	{
+	  /* We treat these cases as a singlebyte character.  */
+	  mbclen = 1;
+	  wc = (wchar_t) pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
+	  if (BE (pstr->trans != NULL, 0))
+	    wc = pstr->trans[wc];
+	  pstr->cur_state = prev_st;
+	}
+
+      /* Write wide character and padding.  */
+      pstr->wcs[byte_idx++] = wc;
+      /* Write paddings.  */
+      for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+	pstr->wcs[byte_idx++] = WEOF;
+    }
+  pstr->valid_len = byte_idx;
+  pstr->valid_raw_len = byte_idx;
+}
+
+/* Build wide character buffer PSTR->WCS like build_wcs_buffer,
+   but for REG_ICASE.  */
+
+static reg_errcode_t
+internal_function
+build_wcs_upper_buffer (re_string_t *pstr)
+{
+  mbstate_t prev_st;
+  Idx src_idx, byte_idx, end_idx, remain_len;
+  size_t mbclen;
+#ifdef _LIBC
+  char buf[MB_LEN_MAX];
+  assert (MB_LEN_MAX >= pstr->mb_cur_max);
+#else
+  char buf[64];
+#endif
+
+  byte_idx = pstr->valid_len;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  /* The following optimization assumes that ASCII characters can be
+     mapped to wide characters with a simple cast.  */
+  if (! pstr->map_notascii && pstr->trans == NULL && !pstr->offsets_needed)
+    {
+      while (byte_idx < end_idx)
+	{
+	  wchar_t wc;
+
+	  if (isascii (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx])
+	      && mbsinit (&pstr->cur_state))
+	    {
+	      /* In case of a singlebyte character.  */
+	      pstr->mbs[byte_idx]
+		= toupper (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx]);
+	      /* The next step uses the assumption that wchar_t is encoded
+		 ASCII-safe: all ASCII values can be converted like this.  */
+	      pstr->wcs[byte_idx] = (wchar_t) pstr->mbs[byte_idx];
+	      ++byte_idx;
+	      continue;
+	    }
+
+	  remain_len = end_idx - byte_idx;
+	  prev_st = pstr->cur_state;
+	  mbclen = mbrtowc (&wc,
+			    ((const char *) pstr->raw_mbs + pstr->raw_mbs_idx
+			     + byte_idx), remain_len, &pstr->cur_state);
+	  if (BE (mbclen < (size_t) -2, 1))
+	    {
+	      wchar_t wcu = wc;
+	      if (iswlower (wc))
+		{
+		  size_t mbcdlen;
+
+		  wcu = towupper (wc);
+		  mbcdlen = wcrtomb (buf, wcu, &prev_st);
+		  if (BE (mbclen == mbcdlen, 1))
+		    memcpy (pstr->mbs + byte_idx, buf, mbclen);
+		  else
+		    {
+		      src_idx = byte_idx;
+		      goto offsets_needed;
+		    }
+		}
+	      else
+		memcpy (pstr->mbs + byte_idx,
+			pstr->raw_mbs + pstr->raw_mbs_idx + byte_idx, mbclen);
+	      pstr->wcs[byte_idx++] = wcu;
+	      /* Write paddings.  */
+	      for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+		pstr->wcs[byte_idx++] = WEOF;
+	    }
+	  else if (mbclen == (size_t) -1 || mbclen == 0)
+	    {
+	      /* It is an invalid character or '\0'.  Just use the byte.  */
+	      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
+	      pstr->mbs[byte_idx] = ch;
+	      /* And also cast it to wide char.  */
+	      pstr->wcs[byte_idx++] = (wchar_t) ch;
+	      if (BE (mbclen == (size_t) -1, 0))
+		pstr->cur_state = prev_st;
+	    }
+	  else
+	    {
+	      /* The buffer doesn't have enough space, finish to build.  */
+	      pstr->cur_state = prev_st;
+	      break;
+	    }
+	}
+      pstr->valid_len = byte_idx;
+      pstr->valid_raw_len = byte_idx;
+      return REG_NOERROR;
+    }
+  else
+    for (src_idx = pstr->valid_raw_len; byte_idx < end_idx;)
+      {
+	wchar_t wc;
+	const char *p;
+      offsets_needed:
+	remain_len = end_idx - byte_idx;
+	prev_st = pstr->cur_state;
+	if (BE (pstr->trans != NULL, 0))
+	  {
+	    int i, ch;
+
+	    for (i = 0; i < pstr->mb_cur_max && i < remain_len; ++i)
+	      {
+		ch = pstr->raw_mbs [pstr->raw_mbs_idx + src_idx + i];
+		buf[i] = pstr->trans[ch];
+	      }
+	    p = (const char *) buf;
+	  }
+	else
+	  p = (const char *) pstr->raw_mbs + pstr->raw_mbs_idx + src_idx;
+	mbclen = mbrtowc (&wc, p, remain_len, &pstr->cur_state);
+	if (BE (mbclen < (size_t) -2, 1))
+	  {
+	    wchar_t wcu = wc;
+	    if (iswlower (wc))
+	      {
+		size_t mbcdlen;
+
+		wcu = towupper (wc);
+		mbcdlen = wcrtomb ((char *) buf, wcu, &prev_st);
+		if (BE (mbclen == mbcdlen, 1))
+		  memcpy (pstr->mbs + byte_idx, buf, mbclen);
+		else if (mbcdlen != (size_t) -1)
+		  {
+		    size_t i;
+
+		    if (byte_idx + mbcdlen > pstr->bufs_len)
+		      {
+			pstr->cur_state = prev_st;
+			break;
+		      }
+
+		    if (pstr->offsets == NULL)
+		      {
+			pstr->offsets = re_malloc (Idx, pstr->bufs_len);
+
+			if (pstr->offsets == NULL)
+			  return REG_ESPACE;
+		      }
+		    if (!pstr->offsets_needed)
+		      {
+			for (i = 0; i < (size_t) byte_idx; ++i)
+			  pstr->offsets[i] = i;
+			pstr->offsets_needed = 1;
+		      }
+
+		    memcpy (pstr->mbs + byte_idx, buf, mbcdlen);
+		    pstr->wcs[byte_idx] = wcu;
+		    pstr->offsets[byte_idx] = src_idx;
+		    for (i = 1; i < mbcdlen; ++i)
+		      {
+			pstr->offsets[byte_idx + i]
+			  = src_idx + (i < mbclen ? i : mbclen - 1);
+			pstr->wcs[byte_idx + i] = WEOF;
+		      }
+		    pstr->len += mbcdlen - mbclen;
+		    if (pstr->raw_stop > src_idx)
+		      pstr->stop += mbcdlen - mbclen;
+		    end_idx = (pstr->bufs_len > pstr->len)
+			      ? pstr->len : pstr->bufs_len;
+		    byte_idx += mbcdlen;
+		    src_idx += mbclen;
+		    continue;
+		  }
+                else
+                  memcpy (pstr->mbs + byte_idx, p, mbclen);
+	      }
+	    else
+	      memcpy (pstr->mbs + byte_idx, p, mbclen);
+
+	    if (BE (pstr->offsets_needed != 0, 0))
+	      {
+		size_t i;
+		for (i = 0; i < mbclen; ++i)
+		  pstr->offsets[byte_idx + i] = src_idx + i;
+	      }
+	    src_idx += mbclen;
+
+	    pstr->wcs[byte_idx++] = wcu;
+	    /* Write paddings.  */
+	    for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+	      pstr->wcs[byte_idx++] = WEOF;
+	  }
+	else if (mbclen == (size_t) -1 || mbclen == 0)
+	  {
+	    /* It is an invalid character or '\0'.  Just use the byte.  */
+	    int ch = pstr->raw_mbs[pstr->raw_mbs_idx + src_idx];
+
+	    if (BE (pstr->trans != NULL, 0))
+	      ch = pstr->trans [ch];
+	    pstr->mbs[byte_idx] = ch;
+
+	    if (BE (pstr->offsets_needed != 0, 0))
+	      pstr->offsets[byte_idx] = src_idx;
+	    ++src_idx;
+
+	    /* And also cast it to wide char.  */
+	    pstr->wcs[byte_idx++] = (wchar_t) ch;
+	    if (BE (mbclen == (size_t) -1, 0))
+	      pstr->cur_state = prev_st;
+	  }
+	else
+	  {
+	    /* The buffer doesn't have enough space, finish to build.  */
+	    pstr->cur_state = prev_st;
+	    break;
+	  }
+      }
+  pstr->valid_len = byte_idx;
+  pstr->valid_raw_len = src_idx;
+  return REG_NOERROR;
+}
+
+/* Skip characters until the index becomes greater than NEW_RAW_IDX.
+   Return the index.  */
+
+static Idx
+internal_function
+re_string_skip_chars (re_string_t *pstr, Idx new_raw_idx, wint_t *last_wc)
+{
+  mbstate_t prev_st;
+  Idx rawbuf_idx;
+  size_t mbclen;
+  wint_t wc = WEOF;
+
+  /* Skip the characters which are not necessary to check.  */
+  for (rawbuf_idx = pstr->raw_mbs_idx + pstr->valid_raw_len;
+       rawbuf_idx < new_raw_idx;)
+    {
+      wchar_t wc2;
+      Idx remain_len;
+      remain_len = pstr->len - rawbuf_idx;
+      prev_st = pstr->cur_state;
+      mbclen = mbrtowc (&wc2, (const char *) pstr->raw_mbs + rawbuf_idx,
+			remain_len, &pstr->cur_state);
+      if (BE (mbclen == (size_t) -2 || mbclen == (size_t) -1 || mbclen == 0, 0))
+	{
+	  /* We treat these cases as a single byte character.  */
+	  if (mbclen == 0 || remain_len == 0)
+	    wc = L'\0';
+	  else
+	    wc = *(unsigned char *) (pstr->raw_mbs + rawbuf_idx);
+	  mbclen = 1;
+	  pstr->cur_state = prev_st;
+	}
+      else
+	wc = wc2;
+      /* Then proceed the next character.  */
+      rawbuf_idx += mbclen;
+    }
+  *last_wc = wc;
+  return rawbuf_idx;
+}
+#endif /* RE_ENABLE_I18N  */
+
+/* Build the buffer PSTR->MBS, and apply the translation if we need.
+   This function is used in case of REG_ICASE.  */
+
+static void
+internal_function
+build_upper_buffer (re_string_t *pstr)
+{
+  Idx char_idx, end_idx;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  for (char_idx = pstr->valid_len; char_idx < end_idx; ++char_idx)
+    {
+      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + char_idx];
+      if (BE (pstr->trans != NULL, 0))
+	ch = pstr->trans[ch];
+      if (islower (ch))
+	pstr->mbs[char_idx] = toupper (ch);
+      else
+	pstr->mbs[char_idx] = ch;
+    }
+  pstr->valid_len = char_idx;
+  pstr->valid_raw_len = char_idx;
+}
+
+/* Apply TRANS to the buffer in PSTR.  */
+
+static void
+internal_function
+re_string_translate_buffer (re_string_t *pstr)
+{
+  Idx buf_idx, end_idx;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  for (buf_idx = pstr->valid_len; buf_idx < end_idx; ++buf_idx)
+    {
+      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + buf_idx];
+      pstr->mbs[buf_idx] = pstr->trans[ch];
+    }
+
+  pstr->valid_len = buf_idx;
+  pstr->valid_raw_len = buf_idx;
+}
+
+/* This function re-construct the buffers.
+   Concretely, convert to wide character in case of pstr->mb_cur_max > 1,
+   convert to upper case in case of REG_ICASE, apply translation.  */
+
+static reg_errcode_t
+internal_function
+re_string_reconstruct (re_string_t *pstr, Idx idx, int eflags)
+{
+  Idx offset;
+
+  if (BE (pstr->raw_mbs_idx <= idx, 0))
+    offset = idx - pstr->raw_mbs_idx;
+  else
+    {
+      /* Reset buffer.  */
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+	memset (&pstr->cur_state, '\0', sizeof (mbstate_t));
+#endif /* RE_ENABLE_I18N */
+      pstr->len = pstr->raw_len;
+      pstr->stop = pstr->raw_stop;
+      pstr->valid_len = 0;
+      pstr->raw_mbs_idx = 0;
+      pstr->valid_raw_len = 0;
+      pstr->offsets_needed = 0;
+      pstr->tip_context = ((eflags & REG_NOTBOL) ? CONTEXT_BEGBUF
+			   : CONTEXT_NEWLINE | CONTEXT_BEGBUF);
+      if (!pstr->mbs_allocated)
+	pstr->mbs = (unsigned char *) pstr->raw_mbs;
+      offset = idx;
+    }
+
+  if (BE (offset != 0, 1))
+    {
+      /* Should the already checked characters be kept?  */
+      if (BE (offset < pstr->valid_raw_len, 1))
+	{
+	  /* Yes, move them to the front of the buffer.  */
+#ifdef RE_ENABLE_I18N
+	  if (BE (pstr->offsets_needed, 0))
+	    {
+	      Idx low = 0, high = pstr->valid_len, mid;
+	      do
+		{
+		  mid = (high + low) / 2;
+		  if (pstr->offsets[mid] > offset)
+		    high = mid;
+		  else if (pstr->offsets[mid] < offset)
+		    low = mid + 1;
+		  else
+		    break;
+		}
+	      while (low < high);
+	      if (pstr->offsets[mid] < offset)
+		++mid;
+	      pstr->tip_context = re_string_context_at (pstr, mid - 1,
+							eflags);
+	      /* This can be quite complicated, so handle specially
+		 only the common and easy case where the character with
+		 different length representation of lower and upper
+		 case is present at or after offset.  */
+	      if (pstr->valid_len > offset
+		  && mid == offset && pstr->offsets[mid] == offset)
+		{
+		  memmove (pstr->wcs, pstr->wcs + offset,
+			   (pstr->valid_len - offset) * sizeof (wint_t));
+		  memmove (pstr->mbs, pstr->mbs + offset, pstr->valid_len - offset);
+		  pstr->valid_len -= offset;
+		  pstr->valid_raw_len -= offset;
+		  for (low = 0; low < pstr->valid_len; low++)
+		    pstr->offsets[low] = pstr->offsets[low + offset] - offset;
+		}
+	      else
+		{
+		  /* Otherwise, just find out how long the partial multibyte
+		     character at offset is and fill it with WEOF/255.  */
+		  pstr->len = pstr->raw_len - idx + offset;
+		  pstr->stop = pstr->raw_stop - idx + offset;
+		  pstr->offsets_needed = 0;
+		  while (mid > 0 && pstr->offsets[mid - 1] == offset)
+		    --mid;
+		  while (mid < pstr->valid_len)
+		    if (pstr->wcs[mid] != WEOF)
+		      break;
+		    else
+		      ++mid;
+		  if (mid == pstr->valid_len)
+		    pstr->valid_len = 0;
+		  else
+		    {
+		      pstr->valid_len = pstr->offsets[mid] - offset;
+		      if (pstr->valid_len)
+			{
+			  for (low = 0; low < pstr->valid_len; ++low)
+			    pstr->wcs[low] = WEOF;
+			  memset (pstr->mbs, 255, pstr->valid_len);
+			}
+		    }
+		  pstr->valid_raw_len = pstr->valid_len;
+		}
+	    }
+	  else
+#endif
+	    {
+	      pstr->tip_context = re_string_context_at (pstr, offset - 1,
+							eflags);
+#ifdef RE_ENABLE_I18N
+	      if (pstr->mb_cur_max > 1)
+		memmove (pstr->wcs, pstr->wcs + offset,
+			 (pstr->valid_len - offset) * sizeof (wint_t));
+#endif /* RE_ENABLE_I18N */
+	      if (BE (pstr->mbs_allocated, 0))
+		memmove (pstr->mbs, pstr->mbs + offset,
+			 pstr->valid_len - offset);
+	      pstr->valid_len -= offset;
+	      pstr->valid_raw_len -= offset;
+#if DEBUG
+	      assert (pstr->valid_len > 0);
+#endif
+	    }
+	}
+      else
+	{
+	  /* No, skip all characters until IDX.  */
+	  Idx prev_valid_len = pstr->valid_len;
+
+#ifdef RE_ENABLE_I18N
+	  if (BE (pstr->offsets_needed, 0))
+	    {
+	      pstr->len = pstr->raw_len - idx + offset;
+	      pstr->stop = pstr->raw_stop - idx + offset;
+	      pstr->offsets_needed = 0;
+	    }
+#endif
+	  pstr->valid_len = 0;
+#ifdef RE_ENABLE_I18N
+	  if (pstr->mb_cur_max > 1)
+	    {
+	      Idx wcs_idx;
+	      wint_t wc = WEOF;
+
+	      if (pstr->is_utf8)
+		{
+		  const unsigned char *raw, *p, *q, *end;
+
+		  /* Special case UTF-8.  Multi-byte chars start with any
+		     byte other than 0x80 - 0xbf.  */
+		  raw = pstr->raw_mbs + pstr->raw_mbs_idx;
+		  end = raw + (offset - pstr->mb_cur_max);
+		  if (end < pstr->raw_mbs)
+		    end = pstr->raw_mbs;
+		  p = raw + offset - 1;
+#ifdef _LIBC
+		  /* We know the wchar_t encoding is UCS4, so for the simple
+		     case, ASCII characters, skip the conversion step.  */
+		  if (isascii (*p) && BE (pstr->trans == NULL, 1))
+		    {
+		      memset (&pstr->cur_state, '\0', sizeof (mbstate_t));
+		      /* pstr->valid_len = 0; */
+		      wc = (wchar_t) *p;
+		    }
+		  else
+#endif
+		    for (; p >= end; --p)
+		      if ((*p & 0xc0) != 0x80)
+			{
+			  mbstate_t cur_state;
+			  wchar_t wc2;
+			  Idx mlen = raw + pstr->len - p;
+			  unsigned char buf[6];
+			  size_t mbclen;
+
+			  q = p;
+			  if (BE (pstr->trans != NULL, 0))
+			    {
+			      int i = mlen < 6 ? mlen : 6;
+			      while (--i >= 0)
+				buf[i] = pstr->trans[p[i]];
+			      q = buf;
+			    }
+			  /* XXX Don't use mbrtowc, we know which conversion
+			     to use (UTF-8 -> UCS4).  */
+			  memset (&cur_state, 0, sizeof (cur_state));
+			  mbclen = mbrtowc (&wc2, (const char *) p, mlen,
+					    &cur_state);
+			  if (raw + offset - p <= mbclen
+			      && mbclen < (size_t) -2)
+			    {
+			      memset (&pstr->cur_state, '\0',
+				      sizeof (mbstate_t));
+			      pstr->valid_len = mbclen - (raw + offset - p);
+			      wc = wc2;
+			    }
+			  break;
+			}
+		}
+
+	      if (wc == WEOF)
+		pstr->valid_len = re_string_skip_chars (pstr, idx, &wc) - idx;
+	      if (wc == WEOF)
+		pstr->tip_context
+		  = re_string_context_at (pstr, prev_valid_len - 1, eflags);
+	      else
+		pstr->tip_context = ((BE (pstr->word_ops_used != 0, 0)
+				      && IS_WIDE_WORD_CHAR (wc))
+				     ? CONTEXT_WORD
+				     : ((IS_WIDE_NEWLINE (wc)
+					 && pstr->newline_anchor)
+					? CONTEXT_NEWLINE : 0));
+	      if (BE (pstr->valid_len, 0))
+		{
+		  for (wcs_idx = 0; wcs_idx < pstr->valid_len; ++wcs_idx)
+		    pstr->wcs[wcs_idx] = WEOF;
+		  if (pstr->mbs_allocated)
+		    memset (pstr->mbs, 255, pstr->valid_len);
+		}
+	      pstr->valid_raw_len = pstr->valid_len;
+	    }
+	  else
+#endif /* RE_ENABLE_I18N */
+	    {
+	      int c = pstr->raw_mbs[pstr->raw_mbs_idx + offset - 1];
+	      pstr->valid_raw_len = 0;
+	      if (pstr->trans)
+		c = pstr->trans[c];
+	      pstr->tip_context = (bitset_contain (pstr->word_char, c)
+				   ? CONTEXT_WORD
+				   : ((IS_NEWLINE (c) && pstr->newline_anchor)
+				      ? CONTEXT_NEWLINE : 0));
+	    }
+	}
+      if (!BE (pstr->mbs_allocated, 0))
+	pstr->mbs += offset;
+    }
+  pstr->raw_mbs_idx = idx;
+  pstr->len -= offset;
+  pstr->stop -= offset;
+
+  /* Then build the buffers.  */
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1)
+    {
+      if (pstr->icase)
+	{
+	  reg_errcode_t ret = build_wcs_upper_buffer (pstr);
+	  if (BE (ret != REG_NOERROR, 0))
+	    return ret;
+	}
+      else
+	build_wcs_buffer (pstr);
+    }
+  else
+#endif /* RE_ENABLE_I18N */
+    if (BE (pstr->mbs_allocated, 0))
+      {
+	if (pstr->icase)
+	  build_upper_buffer (pstr);
+	else if (pstr->trans != NULL)
+	  re_string_translate_buffer (pstr);
+      }
+    else
+      pstr->valid_len = pstr->len;
+
+  pstr->cur_idx = 0;
+  return REG_NOERROR;
+}
+
+static unsigned char
+internal_function __attribute ((pure))
+re_string_peek_byte_case (const re_string_t *pstr, Idx idx)
+{
+  int ch;
+  Idx off;
+
+  /* Handle the common (easiest) cases first.  */
+  if (BE (!pstr->mbs_allocated, 1))
+    return re_string_peek_byte (pstr, idx);
+
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1
+      && ! re_string_is_single_byte_char (pstr, pstr->cur_idx + idx))
+    return re_string_peek_byte (pstr, idx);
+#endif
+
+  off = pstr->cur_idx + idx;
+#ifdef RE_ENABLE_I18N
+  if (pstr->offsets_needed)
+    off = pstr->offsets[off];
+#endif
+
+  ch = pstr->raw_mbs[pstr->raw_mbs_idx + off];
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure that e.g. for tr_TR.UTF-8 BACKSLASH DOTLESS SMALL LETTER I
+     this function returns CAPITAL LETTER I instead of first byte of
+     DOTLESS SMALL LETTER I.  The latter would confuse the parser,
+     since peek_byte_case doesn't advance cur_idx in any way.  */
+  if (pstr->offsets_needed && !isascii (ch))
+    return re_string_peek_byte (pstr, idx);
+#endif
+
+  return ch;
+}
+
+static unsigned char
+internal_function __attribute ((pure))
+re_string_fetch_byte_case (re_string_t *pstr)
+{
+  if (BE (!pstr->mbs_allocated, 1))
+    return re_string_fetch_byte (pstr);
+
+#ifdef RE_ENABLE_I18N
+  if (pstr->offsets_needed)
+    {
+      Idx off;
+      int ch;
+
+      /* For tr_TR.UTF-8 [[:islower:]] there is
+	 [[: CAPITAL LETTER I WITH DOT lower:]] in mbs.  Skip
+	 in that case the whole multi-byte character and return
+	 the original letter.  On the other side, with
+	 [[: DOTLESS SMALL LETTER I return [[:I, as doing
+	 anything else would complicate things too much.  */
+
+      if (!re_string_first_byte (pstr, pstr->cur_idx))
+	return re_string_fetch_byte (pstr);
+
+      off = pstr->offsets[pstr->cur_idx];
+      ch = pstr->raw_mbs[pstr->raw_mbs_idx + off];
+
+      if (! isascii (ch))
+	return re_string_fetch_byte (pstr);
+
+      re_string_skip_bytes (pstr,
+			    re_string_char_size_at (pstr, pstr->cur_idx));
+      return ch;
+    }
+#endif
+
+  return pstr->raw_mbs[pstr->raw_mbs_idx + pstr->cur_idx++];
+}
+
+static void
+internal_function
+re_string_destruct (re_string_t *pstr)
+{
+#ifdef RE_ENABLE_I18N
+  re_free (pstr->wcs);
+  re_free (pstr->offsets);
+#endif /* RE_ENABLE_I18N  */
+  if (pstr->mbs_allocated)
+    re_free (pstr->mbs);
+}
+
+/* Return the context at IDX in INPUT.  */
+
+static unsigned int
+internal_function
+re_string_context_at (const re_string_t *input, Idx idx, int eflags)
+{
+  int c;
+  if (BE (! REG_VALID_INDEX (idx), 0))
+    /* In this case, we use the value stored in input->tip_context,
+       since we can't know the character in input->mbs[-1] here.  */
+    return input->tip_context;
+  if (BE (idx == input->len, 0))
+    return ((eflags & REG_NOTEOL) ? CONTEXT_ENDBUF
+	    : CONTEXT_NEWLINE | CONTEXT_ENDBUF);
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1)
+    {
+      wint_t wc;
+      Idx wc_idx = idx;
+      while(input->wcs[wc_idx] == WEOF)
+	{
+#ifdef DEBUG
+	  /* It must not happen.  */
+	  assert (REG_VALID_INDEX (wc_idx));
+#endif
+	  --wc_idx;
+	  if (! REG_VALID_INDEX (wc_idx))
+	    return input->tip_context;
+	}
+      wc = input->wcs[wc_idx];
+      if (BE (input->word_ops_used != 0, 0) && IS_WIDE_WORD_CHAR (wc))
+	return CONTEXT_WORD;
+      return (IS_WIDE_NEWLINE (wc) && input->newline_anchor
+	      ? CONTEXT_NEWLINE : 0);
+    }
+  else
+#endif
+    {
+      c = re_string_byte_at (input, idx);
+      if (bitset_contain (input->word_char, c))
+	return CONTEXT_WORD;
+      return IS_NEWLINE (c) && input->newline_anchor ? CONTEXT_NEWLINE : 0;
+    }
+}
+
+/* Functions for set operation.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_alloc (re_node_set *set, Idx size)
+{
+  set->alloc = size;
+  set->nelem = 0;
+  set->elems = re_malloc (Idx, size);
+  if (BE (set->elems == NULL, 0))
+    return REG_ESPACE;
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+re_node_set_init_1 (re_node_set *set, Idx elem)
+{
+  set->alloc = 1;
+  set->nelem = 1;
+  set->elems = re_malloc (Idx, 1);
+  if (BE (set->elems == NULL, 0))
+    {
+      set->alloc = set->nelem = 0;
+      return REG_ESPACE;
+    }
+  set->elems[0] = elem;
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+re_node_set_init_2 (re_node_set *set, Idx elem1, Idx elem2)
+{
+  set->alloc = 2;
+  set->elems = re_malloc (Idx, 2);
+  if (BE (set->elems == NULL, 0))
+    return REG_ESPACE;
+  if (elem1 == elem2)
+    {
+      set->nelem = 1;
+      set->elems[0] = elem1;
+    }
+  else
+    {
+      set->nelem = 2;
+      if (elem1 < elem2)
+	{
+	  set->elems[0] = elem1;
+	  set->elems[1] = elem2;
+	}
+      else
+	{
+	  set->elems[0] = elem2;
+	  set->elems[1] = elem1;
+	}
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+re_node_set_init_copy (re_node_set *dest, const re_node_set *src)
+{
+  dest->nelem = src->nelem;
+  if (src->nelem > 0)
+    {
+      dest->alloc = dest->nelem;
+      dest->elems = re_malloc (Idx, dest->alloc);
+      if (BE (dest->elems == NULL, 0))
+	{
+	  dest->alloc = dest->nelem = 0;
+	  return REG_ESPACE;
+	}
+      memcpy (dest->elems, src->elems, src->nelem * sizeof (Idx));
+    }
+  else
+    re_node_set_init_empty (dest);
+  return REG_NOERROR;
+}
+
+/* Calculate the intersection of the sets SRC1 and SRC2. And merge it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.
+   Note: We assume dest->elems is NULL, when dest->alloc is 0.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
+			   const re_node_set *src2)
+{
+  Idx i1, i2, is, id, delta, sbase;
+  if (src1->nelem == 0 || src2->nelem == 0)
+    return REG_NOERROR;
+
+  /* We need dest->nelem + 2 * elems_in_intersection; this is a
+     conservative estimate.  */
+  if (src1->nelem + src2->nelem + dest->nelem > dest->alloc)
+    {
+      Idx new_alloc = src1->nelem + src2->nelem + dest->alloc;
+      Idx *new_elems = re_realloc (dest->elems, Idx, new_alloc);
+      if (BE (new_elems == NULL, 0))
+        return REG_ESPACE;
+      dest->elems = new_elems;
+      dest->alloc = new_alloc;
+    }
+
+  /* Find the items in the intersection of SRC1 and SRC2, and copy
+     into the top of DEST those that are not already in DEST itself.  */
+  sbase = dest->nelem + src1->nelem + src2->nelem;
+  i1 = src1->nelem - 1;
+  i2 = src2->nelem - 1;
+  id = dest->nelem - 1;
+  for (;;)
+    {
+      if (src1->elems[i1] == src2->elems[i2])
+	{
+	  /* Try to find the item in DEST.  Maybe we could binary search?  */
+	  while (REG_VALID_INDEX (id) && dest->elems[id] > src1->elems[i1])
+	    --id;
+
+          if (! REG_VALID_INDEX (id) || dest->elems[id] != src1->elems[i1])
+            dest->elems[--sbase] = src1->elems[i1];
+
+	  if (! REG_VALID_INDEX (--i1) || ! REG_VALID_INDEX (--i2))
+	    break;
+	}
+
+      /* Lower the highest of the two items.  */
+      else if (src1->elems[i1] < src2->elems[i2])
+	{
+	  if (! REG_VALID_INDEX (--i2))
+	    break;
+	}
+      else
+	{
+	  if (! REG_VALID_INDEX (--i1))
+	    break;
+	}
+    }
+
+  id = dest->nelem - 1;
+  is = dest->nelem + src1->nelem + src2->nelem - 1;
+  delta = is - sbase + 1;
+
+  /* Now copy.  When DELTA becomes zero, the remaining
+     DEST elements are already in place; this is more or
+     less the same loop that is in re_node_set_merge.  */
+  dest->nelem += delta;
+  if (delta > 0 && REG_VALID_INDEX (id))
+    for (;;)
+      {
+        if (dest->elems[is] > dest->elems[id])
+          {
+            /* Copy from the top.  */
+            dest->elems[id + delta--] = dest->elems[is--];
+            if (delta == 0)
+              break;
+          }
+        else
+          {
+            /* Slide from the bottom.  */
+            dest->elems[id + delta] = dest->elems[id];
+            if (! REG_VALID_INDEX (--id))
+              break;
+          }
+      }
+
+  /* Copy remaining SRC elements.  */
+  memcpy (dest->elems, dest->elems + sbase, delta * sizeof (Idx));
+
+  return REG_NOERROR;
+}
+
+/* Calculate the union set of the sets SRC1 and SRC2. And store it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_init_union (re_node_set *dest, const re_node_set *src1,
+			const re_node_set *src2)
+{
+  Idx i1, i2, id;
+  if (src1 != NULL && src1->nelem > 0 && src2 != NULL && src2->nelem > 0)
+    {
+      dest->alloc = src1->nelem + src2->nelem;
+      dest->elems = re_malloc (Idx, dest->alloc);
+      if (BE (dest->elems == NULL, 0))
+	return REG_ESPACE;
+    }
+  else
+    {
+      if (src1 != NULL && src1->nelem > 0)
+	return re_node_set_init_copy (dest, src1);
+      else if (src2 != NULL && src2->nelem > 0)
+	return re_node_set_init_copy (dest, src2);
+      else
+	re_node_set_init_empty (dest);
+      return REG_NOERROR;
+    }
+  for (i1 = i2 = id = 0 ; i1 < src1->nelem && i2 < src2->nelem ;)
+    {
+      if (src1->elems[i1] > src2->elems[i2])
+	{
+	  dest->elems[id++] = src2->elems[i2++];
+	  continue;
+	}
+      if (src1->elems[i1] == src2->elems[i2])
+	++i2;
+      dest->elems[id++] = src1->elems[i1++];
+    }
+  if (i1 < src1->nelem)
+    {
+      memcpy (dest->elems + id, src1->elems + i1,
+	     (src1->nelem - i1) * sizeof (Idx));
+      id += src1->nelem - i1;
+    }
+  else if (i2 < src2->nelem)
+    {
+      memcpy (dest->elems + id, src2->elems + i2,
+	     (src2->nelem - i2) * sizeof (Idx));
+      id += src2->nelem - i2;
+    }
+  dest->nelem = id;
+  return REG_NOERROR;
+}
+
+/* Calculate the union set of the sets DEST and SRC. And store it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_merge (re_node_set *dest, const re_node_set *src)
+{
+  Idx is, id, sbase, delta;
+  if (src == NULL || src->nelem == 0)
+    return REG_NOERROR;
+  if (dest->alloc < 2 * src->nelem + dest->nelem)
+    {
+      Idx new_alloc = 2 * (src->nelem + dest->alloc);
+      Idx *new_buffer = re_realloc (dest->elems, Idx, new_alloc);
+      if (BE (new_buffer == NULL, 0))
+	return REG_ESPACE;
+      dest->elems = new_buffer;
+      dest->alloc = new_alloc;
+    }
+
+  if (BE (dest->nelem == 0, 0))
+    {
+      dest->nelem = src->nelem;
+      memcpy (dest->elems, src->elems, src->nelem * sizeof (Idx));
+      return REG_NOERROR;
+    }
+
+  /* Copy into the top of DEST the items of SRC that are not
+     found in DEST.  Maybe we could binary search in DEST?  */
+  for (sbase = dest->nelem + 2 * src->nelem,
+       is = src->nelem - 1, id = dest->nelem - 1;
+       REG_VALID_INDEX (is) && REG_VALID_INDEX (id); )
+    {
+      if (dest->elems[id] == src->elems[is])
+        is--, id--;
+      else if (dest->elems[id] < src->elems[is])
+        dest->elems[--sbase] = src->elems[is--];
+      else /* if (dest->elems[id] > src->elems[is]) */
+        --id;
+    }
+
+  if (REG_VALID_INDEX (is))
+    {
+      /* If DEST is exhausted, the remaining items of SRC must be unique.  */
+      sbase -= is + 1;
+      memcpy (dest->elems + sbase, src->elems, (is + 1) * sizeof (Idx));
+    }
+
+  id = dest->nelem - 1;
+  is = dest->nelem + 2 * src->nelem - 1;
+  delta = is - sbase + 1;
+  if (delta == 0)
+    return REG_NOERROR;
+
+  /* Now copy.  When DELTA becomes zero, the remaining
+     DEST elements are already in place.  */
+  dest->nelem += delta;
+  for (;;)
+    {
+      if (dest->elems[is] > dest->elems[id])
+        {
+	  /* Copy from the top.  */
+          dest->elems[id + delta--] = dest->elems[is--];
+	  if (delta == 0)
+	    break;
+	}
+      else
+        {
+          /* Slide from the bottom.  */
+          dest->elems[id + delta] = dest->elems[id];
+	  if (! REG_VALID_INDEX (--id))
+	    {
+	      /* Copy remaining SRC elements.  */
+	      memcpy (dest->elems, dest->elems + sbase,
+	              delta * sizeof (Idx));
+	      break;
+	    }
+	}
+    }
+
+  return REG_NOERROR;
+}
+
+/* Insert the new element ELEM to the re_node_set* SET.
+   SET should not already have ELEM.
+   Return true if successful.  */
+
+static bool
+internal_function
+re_node_set_insert (re_node_set *set, Idx elem)
+{
+  Idx idx;
+  /* In case the set is empty.  */
+  if (set->alloc == 0)
+    return BE (re_node_set_init_1 (set, elem) == REG_NOERROR, 1);
+
+  if (BE (set->nelem, 0) == 0)
+    {
+      /* We already guaranteed above that set->alloc != 0.  */
+      set->elems[0] = elem;
+      ++set->nelem;
+      return true;
+    }
+
+  /* Realloc if we need.  */
+  if (set->alloc == set->nelem)
+    {
+      Idx *new_elems;
+      set->alloc = set->alloc * 2;
+      new_elems = re_realloc (set->elems, Idx, set->alloc);
+      if (BE (new_elems == NULL, 0))
+	return false;
+      set->elems = new_elems;
+    }
+
+  /* Move the elements which follows the new element.  Test the
+     first element separately to skip a check in the inner loop.  */
+  if (elem < set->elems[0])
+    {
+      idx = 0;
+      for (idx = set->nelem; idx > 0; idx--)
+        set->elems[idx] = set->elems[idx - 1];
+    }
+  else
+    {
+      for (idx = set->nelem; set->elems[idx - 1] > elem; idx--)
+        set->elems[idx] = set->elems[idx - 1];
+    }
+
+  /* Insert the new element.  */
+  set->elems[idx] = elem;
+  ++set->nelem;
+  return true;
+}
+
+/* Insert the new element ELEM to the re_node_set* SET.
+   SET should not already have any element greater than or equal to ELEM.
+   Return true if successful.  */
+
+static bool
+internal_function
+re_node_set_insert_last (re_node_set *set, Idx elem)
+{
+  /* Realloc if we need.  */
+  if (set->alloc == set->nelem)
+    {
+      Idx *new_elems;
+      set->alloc = (set->alloc + 1) * 2;
+      new_elems = re_realloc (set->elems, Idx, set->alloc);
+      if (BE (new_elems == NULL, 0))
+	return false;
+      set->elems = new_elems;
+    }
+
+  /* Insert the new element.  */
+  set->elems[set->nelem++] = elem;
+  return true;
+}
+
+/* Compare two node sets SET1 and SET2.
+   Return true if SET1 and SET2 are equivalent.  */
+
+static bool
+internal_function __attribute ((pure))
+re_node_set_compare (const re_node_set *set1, const re_node_set *set2)
+{
+  Idx i;
+  if (set1 == NULL || set2 == NULL || set1->nelem != set2->nelem)
+    return false;
+  for (i = set1->nelem ; REG_VALID_INDEX (--i) ; )
+    if (set1->elems[i] != set2->elems[i])
+      return false;
+  return true;
+}
+
+/* Return (idx + 1) if SET contains the element ELEM, return 0 otherwise.  */
+
+static Idx
+internal_function __attribute ((pure))
+re_node_set_contains (const re_node_set *set, Idx elem)
+{
+  __re_size_t idx, right, mid;
+  if (! REG_VALID_NONZERO_INDEX (set->nelem))
+    return 0;
+
+  /* Binary search the element.  */
+  idx = 0;
+  right = set->nelem - 1;
+  while (idx < right)
+    {
+      mid = (idx + right) / 2;
+      if (set->elems[mid] < elem)
+	idx = mid + 1;
+      else
+	right = mid;
+    }
+  return set->elems[idx] == elem ? idx + 1 : 0;
+}
+
+static void
+internal_function
+re_node_set_remove_at (re_node_set *set, Idx idx)
+{
+  if (idx < 0 || idx >= set->nelem)
+    return;
+  --set->nelem;
+  for (; idx < set->nelem; idx++)
+    set->elems[idx] = set->elems[idx + 1];
+}
+
+
+/* Add the token TOKEN to dfa->nodes, and return the index of the token.
+   Or return REG_MISSING if an error occurred.  */
+
+static Idx
+internal_function
+re_dfa_add_node (re_dfa_t *dfa, re_token_t token)
+{
+  if (BE (dfa->nodes_len >= dfa->nodes_alloc, 0))
+    {
+      size_t new_nodes_alloc = dfa->nodes_alloc * 2;
+      Idx *new_nexts, *new_indices;
+      re_node_set *new_edests, *new_eclosures;
+      re_token_t *new_nodes;
+      size_t max_object_size =
+	MAX (sizeof (re_token_t),
+	     MAX (sizeof (re_node_set),
+		  sizeof (Idx)));
+
+      /* Avoid overflows.  */
+      if (BE (SIZE_MAX / 2 / max_object_size < dfa->nodes_alloc, 0))
+	return REG_MISSING;
+
+      new_nodes = re_realloc (dfa->nodes, re_token_t, new_nodes_alloc);
+      if (BE (new_nodes == NULL, 0))
+	return REG_MISSING;
+      dfa->nodes = new_nodes;
+      new_nexts = re_realloc (dfa->nexts, Idx, new_nodes_alloc);
+      new_indices = re_realloc (dfa->org_indices, Idx, new_nodes_alloc);
+      new_edests = re_realloc (dfa->edests, re_node_set, new_nodes_alloc);
+      new_eclosures = re_realloc (dfa->eclosures, re_node_set, new_nodes_alloc);
+      if (BE (new_nexts == NULL || new_indices == NULL
+	      || new_edests == NULL || new_eclosures == NULL, 0))
+	return REG_MISSING;
+      dfa->nexts = new_nexts;
+      dfa->org_indices = new_indices;
+      dfa->edests = new_edests;
+      dfa->eclosures = new_eclosures;
+      dfa->nodes_alloc = new_nodes_alloc;
+    }
+  dfa->nodes[dfa->nodes_len] = token;
+  dfa->nodes[dfa->nodes_len].constraint = 0;
+#ifdef RE_ENABLE_I18N
+  {
+  int type = token.type;
+  dfa->nodes[dfa->nodes_len].accept_mb =
+    (type == OP_PERIOD && dfa->mb_cur_max > 1) || type == COMPLEX_BRACKET;
+  }
+#endif
+  dfa->nexts[dfa->nodes_len] = REG_MISSING;
+  re_node_set_init_empty (dfa->edests + dfa->nodes_len);
+  re_node_set_init_empty (dfa->eclosures + dfa->nodes_len);
+  return dfa->nodes_len++;
+}
+
+static inline re_hashval_t
+internal_function
+calc_state_hash (const re_node_set *nodes, unsigned int context)
+{
+  re_hashval_t hash = nodes->nelem + context;
+  Idx i;
+  for (i = 0 ; i < nodes->nelem ; i++)
+    hash += nodes->elems[i];
+  return hash;
+}
+
+/* Search for the state whose node_set is equivalent to NODES.
+   Return the pointer to the state, if we found it in the DFA.
+   Otherwise create the new one and return it.  In case of an error
+   return NULL and set the error code in ERR.
+   Note: - We assume NULL as the invalid state, then it is possible that
+	   return value is NULL and ERR is REG_NOERROR.
+	 - We never return non-NULL value in case of any errors, it is for
+	   optimization.  */
+
+static re_dfastate_t *
+internal_function
+re_acquire_state (reg_errcode_t *err, const re_dfa_t *dfa,
+		  const re_node_set *nodes)
+{
+  re_hashval_t hash;
+  re_dfastate_t *new_state;
+  struct re_state_table_entry *spot;
+  Idx i;
+#ifdef lint
+  /* Suppress bogus uninitialized-variable warnings.  */
+  *err = REG_NOERROR;
+#endif
+  if (BE (nodes->nelem == 0, 0))
+    {
+      *err = REG_NOERROR;
+      return NULL;
+    }
+  hash = calc_state_hash (nodes, 0);
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+
+  for (i = 0 ; i < spot->num ; i++)
+    {
+      re_dfastate_t *state = spot->array[i];
+      if (hash != state->hash)
+	continue;
+      if (re_node_set_compare (&state->nodes, nodes))
+	return state;
+    }
+
+  /* There are no appropriate state in the dfa, create the new one.  */
+  new_state = create_ci_newstate (dfa, nodes, hash);
+  if (BE (new_state == NULL, 0))
+    *err = REG_ESPACE;
+
+  return new_state;
+}
+
+/* Search for the state whose node_set is equivalent to NODES and
+   whose context is equivalent to CONTEXT.
+   Return the pointer to the state, if we found it in the DFA.
+   Otherwise create the new one and return it.  In case of an error
+   return NULL and set the error code in ERR.
+   Note: - We assume NULL as the invalid state, then it is possible that
+	   return value is NULL and ERR is REG_NOERROR.
+	 - We never return non-NULL value in case of any errors, it is for
+	   optimization.  */
+
+static re_dfastate_t *
+internal_function
+re_acquire_state_context (reg_errcode_t *err, const re_dfa_t *dfa,
+			  const re_node_set *nodes, unsigned int context)
+{
+  re_hashval_t hash;
+  re_dfastate_t *new_state;
+  struct re_state_table_entry *spot;
+  Idx i;
+#ifdef lint
+  /* Suppress bogus uninitialized-variable warnings.  */
+  *err = REG_NOERROR;
+#endif
+  if (nodes->nelem == 0)
+    {
+      *err = REG_NOERROR;
+      return NULL;
+    }
+  hash = calc_state_hash (nodes, context);
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+
+  for (i = 0 ; i < spot->num ; i++)
+    {
+      re_dfastate_t *state = spot->array[i];
+      if (state->hash == hash
+	  && state->context == context
+	  && re_node_set_compare (state->entrance_nodes, nodes))
+	return state;
+    }
+  /* There are no appropriate state in `dfa', create the new one.  */
+  new_state = create_cd_newstate (dfa, nodes, context, hash);
+  if (BE (new_state == NULL, 0))
+    *err = REG_ESPACE;
+
+  return new_state;
+}
+
+/* Finish initialization of the new state NEWSTATE, and using its hash value
+   HASH put in the appropriate bucket of DFA's state table.  Return value
+   indicates the error code if failed.  */
+
+static reg_errcode_t
+register_state (const re_dfa_t *dfa, re_dfastate_t *newstate,
+		re_hashval_t hash)
+{
+  struct re_state_table_entry *spot;
+  reg_errcode_t err;
+  Idx i;
+
+  newstate->hash = hash;
+  err = re_node_set_alloc (&newstate->non_eps_nodes, newstate->nodes.nelem);
+  if (BE (err != REG_NOERROR, 0))
+    return REG_ESPACE;
+  for (i = 0; i < newstate->nodes.nelem; i++)
+    {
+      Idx elem = newstate->nodes.elems[i];
+      if (!IS_EPSILON_NODE (dfa->nodes[elem].type))
+	if (BE (! re_node_set_insert_last (&newstate->non_eps_nodes, elem), 0))
+	  return REG_ESPACE;
+    }
+
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+  if (BE (spot->alloc <= spot->num, 0))
+    {
+      Idx new_alloc = 2 * spot->num + 2;
+      re_dfastate_t **new_array = re_realloc (spot->array, re_dfastate_t *,
+					      new_alloc);
+      if (BE (new_array == NULL, 0))
+	return REG_ESPACE;
+      spot->array = new_array;
+      spot->alloc = new_alloc;
+    }
+  spot->array[spot->num++] = newstate;
+  return REG_NOERROR;
+}
+
+static void
+free_state (re_dfastate_t *state)
+{
+  re_node_set_free (&state->non_eps_nodes);
+  re_node_set_free (&state->inveclosure);
+  if (state->entrance_nodes != &state->nodes)
+    {
+      re_node_set_free (state->entrance_nodes);
+      re_free (state->entrance_nodes);
+    }
+  re_node_set_free (&state->nodes);
+  re_free (state->word_trtable);
+  re_free (state->trtable);
+  re_free (state);
+}
+
+/* Create the new state which is independ of contexts.
+   Return the new state if succeeded, otherwise return NULL.  */
+
+static re_dfastate_t *
+internal_function
+create_ci_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
+		    re_hashval_t hash)
+{
+  Idx i;
+  reg_errcode_t err;
+  re_dfastate_t *newstate;
+
+  newstate = (re_dfastate_t *) calloc (sizeof (re_dfastate_t), 1);
+  if (BE (newstate == NULL, 0))
+    return NULL;
+  err = re_node_set_init_copy (&newstate->nodes, nodes);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      re_free (newstate);
+      return NULL;
+    }
+
+  newstate->entrance_nodes = &newstate->nodes;
+  for (i = 0 ; i < nodes->nelem ; i++)
+    {
+      re_token_t *node = dfa->nodes + nodes->elems[i];
+      re_token_type_t type = node->type;
+      if (type == CHARACTER && !node->constraint)
+	continue;
+#ifdef RE_ENABLE_I18N
+      newstate->accept_mb |= node->accept_mb;
+#endif /* RE_ENABLE_I18N */
+
+      /* If the state has the halt node, the state is a halt state.  */
+      if (type == END_OF_RE)
+	newstate->halt = 1;
+      else if (type == OP_BACK_REF)
+	newstate->has_backref = 1;
+      else if (type == ANCHOR || node->constraint)
+	newstate->has_constraint = 1;
+    }
+  err = register_state (dfa, newstate, hash);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_state (newstate);
+      newstate = NULL;
+    }
+  return newstate;
+}
+
+/* Create the new state which is depend on the context CONTEXT.
+   Return the new state if succeeded, otherwise return NULL.  */
+
+static re_dfastate_t *
+internal_function
+create_cd_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
+		    unsigned int context, re_hashval_t hash)
+{
+  Idx i, nctx_nodes = 0;
+  reg_errcode_t err;
+  re_dfastate_t *newstate;
+
+  newstate = (re_dfastate_t *) calloc (sizeof (re_dfastate_t), 1);
+  if (BE (newstate == NULL, 0))
+    return NULL;
+  err = re_node_set_init_copy (&newstate->nodes, nodes);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      re_free (newstate);
+      return NULL;
+    }
+
+  newstate->context = context;
+  newstate->entrance_nodes = &newstate->nodes;
+
+  for (i = 0 ; i < nodes->nelem ; i++)
+    {
+      unsigned int constraint = 0;
+      re_token_t *node = dfa->nodes + nodes->elems[i];
+      re_token_type_t type = node->type;
+      if (node->constraint)
+	constraint = node->constraint;
+
+      if (type == CHARACTER && !constraint)
+	continue;
+#ifdef RE_ENABLE_I18N
+      newstate->accept_mb |= node->accept_mb;
+#endif /* RE_ENABLE_I18N */
+
+      /* If the state has the halt node, the state is a halt state.  */
+      if (type == END_OF_RE)
+	newstate->halt = 1;
+      else if (type == OP_BACK_REF)
+	newstate->has_backref = 1;
+      else if (type == ANCHOR)
+	constraint = node->opr.ctx_type;
+
+      if (constraint)
+	{
+	  if (newstate->entrance_nodes == &newstate->nodes)
+	    {
+	      newstate->entrance_nodes = re_malloc (re_node_set, 1);
+	      if (BE (newstate->entrance_nodes == NULL, 0))
+		{
+		  free_state (newstate);
+		  return NULL;
+		}
+	      re_node_set_init_copy (newstate->entrance_nodes, nodes);
+	      nctx_nodes = 0;
+	      newstate->has_constraint = 1;
+	    }
+
+	  if (NOT_SATISFY_PREV_CONSTRAINT (constraint,context))
+	    {
+	      re_node_set_remove_at (&newstate->nodes, i - nctx_nodes);
+	      ++nctx_nodes;
+	    }
+	}
+    }
+  err = register_state (dfa, newstate, hash);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_state (newstate);
+      newstate = NULL;
+    }
+  return  newstate;
+}
diff --git a/src/bin/m4/lib/regex_internal.h b/src/bin/m4/lib/regex_internal.h
new file mode 100644
index 0000000000..cc9b5b79c2
--- /dev/null
+++ b/src/bin/m4/lib/regex_internal.h
@@ -0,0 +1,865 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#ifndef _REGEX_INTERNAL_H
+#define _REGEX_INTERNAL_H 1
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef _LIBC
+# include "strcase.h"
+#endif
+
+#if defined HAVE_LANGINFO_H || defined HAVE_LANGINFO_CODESET || defined _LIBC
+# include <langinfo.h>
+#endif
+#if defined HAVE_LOCALE_H || defined _LIBC
+# include <locale.h>
+#endif
+#if defined HAVE_WCHAR_H || defined _LIBC
+# include <wchar.h>
+#endif /* HAVE_WCHAR_H || _LIBC */
+#if defined HAVE_WCTYPE_H || defined _LIBC
+# include <wctype.h>
+#endif /* HAVE_WCTYPE_H || _LIBC */
+#include <stdint.h>
+#if defined _LIBC
+# include <bits/libc-lock.h>
+#else
+# define __libc_lock_init(NAME) do { } while (0)
+# define __libc_lock_lock(NAME) do { } while (0)
+# define __libc_lock_unlock(NAME) do { } while (0)
+#endif
+
+/* In case that the system doesn't have isblank().  */
+#if !defined _LIBC && !HAVE_DECL_ISBLANK && !defined isblank
+# define isblank(ch) ((ch) == ' ' || (ch) == '\t')
+#endif
+
+#ifdef _LIBC
+# ifndef _RE_DEFINE_LOCALE_FUNCTIONS
+#  define _RE_DEFINE_LOCALE_FUNCTIONS 1
+#   include <locale/localeinfo.h>
+#   include <locale/elem-hash.h>
+#   include <locale/coll-lookup.h>
+# endif
+#endif
+
+/* This is for other GNU distributions with internationalized messages.  */
+#if (HAVE_LIBINTL_H && ENABLE_NLS) || defined _LIBC
+# include <libintl.h>
+# ifdef _LIBC
+#  undef gettext
+#  define gettext(msgid) \
+  INTUSE(__dcgettext) (_libc_intl_domainname, msgid, LC_MESSAGES)
+# endif
+#else
+# define gettext(msgid) (msgid)
+#endif
+
+#ifndef gettext_noop
+/* This define is so xgettext can find the internationalizable
+   strings.  */
+# define gettext_noop(String) String
+#endif
+
+/* For loser systems without the definition.  */
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+#if (defined MB_CUR_MAX && HAVE_LOCALE_H && HAVE_WCTYPE_H && HAVE_WCHAR_H && HAVE_WCRTOMB && HAVE_MBRTOWC && HAVE_WCSCOLL) || _LIBC
+# define RE_ENABLE_I18N
+#endif
+
+#if __GNUC__ >= 3
+# define BE(expr, val) __builtin_expect (expr, val)
+#else
+# define BE(expr, val) (expr)
+# ifdef _LIBC
+#  define inline
+# endif
+#endif
+
+/* Number of ASCII characters.  */
+#define ASCII_CHARS 0x80
+
+/* Number of single byte characters.  */
+#define SBC_MAX (UCHAR_MAX + 1)
+
+#define COLL_ELEM_LEN_MAX 8
+
+/* The character which represents newline.  */
+#define NEWLINE_CHAR '\n'
+#define WIDE_NEWLINE_CHAR L'\n'
+
+/* Rename to standard API for using out of glibc.  */
+#ifndef _LIBC
+# define __wctype wctype
+# define __iswctype iswctype
+# define __btowc btowc
+# ifndef __mempcpy
+#  define __mempcpy mempcpy
+# endif
+# define __wcrtomb wcrtomb
+# define __regfree regfree
+# define attribute_hidden
+#endif /* not _LIBC */
+
+#if __GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
+# define __attribute(arg) __attribute__ (arg)
+#else
+# define __attribute(arg)
+#endif
+
+typedef __re_idx_t Idx;
+
+/* Special return value for failure to match.  */
+#define REG_MISSING ((Idx) -1)
+
+/* Special return value for internal error.  */
+#define REG_ERROR ((Idx) -2)
+
+/* Test whether N is a valid index, and is not one of the above.  */
+#ifdef _REGEX_LARGE_OFFSETS
+# define REG_VALID_INDEX(n) ((Idx) (n) < REG_ERROR)
+#else
+# define REG_VALID_INDEX(n) (0 <= (n))
+#endif
+
+/* Test whether N is a valid nonzero index.  */
+#ifdef _REGEX_LARGE_OFFSETS
+# define REG_VALID_NONZERO_INDEX(n) ((Idx) ((n) - 1) < (Idx) (REG_ERROR - 1))
+#else
+# define REG_VALID_NONZERO_INDEX(n) (0 < (n))
+#endif
+
+/* A hash value, suitable for computing hash tables.  */
+typedef __re_size_t re_hashval_t;
+
+/* An integer used to represent a set of bits.  It must be unsigned,
+   and must be at least as wide as unsigned int.  */
+typedef unsigned long int bitset_word_t;
+/* All bits set in a bitset_word_t.  */
+#define BITSET_WORD_MAX ULONG_MAX
+
+/* Number of bits in a bitset_word_t.  For portability to hosts with
+   padding bits, do not use '(sizeof (bitset_word_t) * CHAR_BIT)';
+   instead, deduce it directly from BITSET_WORD_MAX.  Avoid
+   greater-than-32-bit integers and unconditional shifts by more than
+   31 bits, as they're not portable.  */
+#if BITSET_WORD_MAX == 0xffffffff
+# define BITSET_WORD_BITS 32
+#elif BITSET_WORD_MAX >> 31 >> 5 == 1
+# define BITSET_WORD_BITS 36
+#elif BITSET_WORD_MAX >> 31 >> 16 == 1
+# define BITSET_WORD_BITS 48
+#elif BITSET_WORD_MAX >> 31 >> 28 == 1
+# define BITSET_WORD_BITS 60
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 1 == 1
+# define BITSET_WORD_BITS 64
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 9 == 1
+# define BITSET_WORD_BITS 72
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 3 == 1
+# define BITSET_WORD_BITS 128
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 7 == 1
+# define BITSET_WORD_BITS 256
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 7 > 1
+# define BITSET_WORD_BITS 257 /* any value > SBC_MAX will do here */
+# if BITSET_WORD_BITS <= SBC_MAX
+#  error "Invalid SBC_MAX"
+# endif
+#elif BITSET_WORD_MAX == (0xffffffff + 2) * 0xffffffff
+/* Work around a bug in 64-bit PGC (before version 6.1-2), where the
+   preprocessor mishandles large unsigned values as if they were signed.  */
+# define BITSET_WORD_BITS 64
+#else
+# error "Add case for new bitset_word_t size"
+#endif
+
+/* Number of bitset_word_t values in a bitset_t.  */
+#define BITSET_WORDS ((SBC_MAX + BITSET_WORD_BITS - 1) / BITSET_WORD_BITS)
+
+typedef bitset_word_t bitset_t[BITSET_WORDS];
+typedef bitset_word_t *re_bitset_ptr_t;
+typedef const bitset_word_t *re_const_bitset_ptr_t;
+
+#define PREV_WORD_CONSTRAINT 0x0001
+#define PREV_NOTWORD_CONSTRAINT 0x0002
+#define NEXT_WORD_CONSTRAINT 0x0004
+#define NEXT_NOTWORD_CONSTRAINT 0x0008
+#define PREV_NEWLINE_CONSTRAINT 0x0010
+#define NEXT_NEWLINE_CONSTRAINT 0x0020
+#define PREV_BEGBUF_CONSTRAINT 0x0040
+#define NEXT_ENDBUF_CONSTRAINT 0x0080
+#define WORD_DELIM_CONSTRAINT 0x0100
+#define NOT_WORD_DELIM_CONSTRAINT 0x0200
+
+typedef enum
+{
+  INSIDE_WORD = PREV_WORD_CONSTRAINT | NEXT_WORD_CONSTRAINT,
+  WORD_FIRST = PREV_NOTWORD_CONSTRAINT | NEXT_WORD_CONSTRAINT,
+  WORD_LAST = PREV_WORD_CONSTRAINT | NEXT_NOTWORD_CONSTRAINT,
+  INSIDE_NOTWORD = PREV_NOTWORD_CONSTRAINT | NEXT_NOTWORD_CONSTRAINT,
+  LINE_FIRST = PREV_NEWLINE_CONSTRAINT,
+  LINE_LAST = NEXT_NEWLINE_CONSTRAINT,
+  BUF_FIRST = PREV_BEGBUF_CONSTRAINT,
+  BUF_LAST = NEXT_ENDBUF_CONSTRAINT,
+  WORD_DELIM = WORD_DELIM_CONSTRAINT,
+  NOT_WORD_DELIM = NOT_WORD_DELIM_CONSTRAINT
+} re_context_type;
+
+typedef struct
+{
+  Idx alloc;
+  Idx nelem;
+  Idx *elems;
+} re_node_set;
+
+typedef enum
+{
+  NON_TYPE = 0,
+
+  /* Node type, These are used by token, node, tree.  */
+  CHARACTER = 1,
+  END_OF_RE = 2,
+  SIMPLE_BRACKET = 3,
+  OP_BACK_REF = 4,
+  OP_PERIOD = 5,
+#ifdef RE_ENABLE_I18N
+  COMPLEX_BRACKET = 6,
+  OP_UTF8_PERIOD = 7,
+#endif /* RE_ENABLE_I18N */
+
+  /* We define EPSILON_BIT as a macro so that OP_OPEN_SUBEXP is used
+     when the debugger shows values of this enum type.  */
+#define EPSILON_BIT 8
+  OP_OPEN_SUBEXP = EPSILON_BIT | 0,
+  OP_CLOSE_SUBEXP = EPSILON_BIT | 1,
+  OP_ALT = EPSILON_BIT | 2,
+  OP_DUP_ASTERISK = EPSILON_BIT | 3,
+  ANCHOR = EPSILON_BIT | 4,
+
+  /* Tree type, these are used only by tree. */
+  CONCAT = 16,
+  SUBEXP = 17,
+
+  /* Token type, these are used only by token.  */
+  OP_DUP_PLUS = 18,
+  OP_DUP_QUESTION,
+  OP_OPEN_BRACKET,
+  OP_CLOSE_BRACKET,
+  OP_CHARSET_RANGE,
+  OP_OPEN_DUP_NUM,
+  OP_CLOSE_DUP_NUM,
+  OP_NON_MATCH_LIST,
+  OP_OPEN_COLL_ELEM,
+  OP_CLOSE_COLL_ELEM,
+  OP_OPEN_EQUIV_CLASS,
+  OP_CLOSE_EQUIV_CLASS,
+  OP_OPEN_CHAR_CLASS,
+  OP_CLOSE_CHAR_CLASS,
+  OP_WORD,
+  OP_NOTWORD,
+  OP_SPACE,
+  OP_NOTSPACE,
+  BACK_SLASH
+
+} re_token_type_t;
+
+#ifdef RE_ENABLE_I18N
+typedef struct
+{
+  /* Multibyte characters.  */
+  wchar_t *mbchars;
+
+  /* Collating symbols.  */
+# ifdef _LIBC
+  int32_t *coll_syms;
+# endif
+
+  /* Equivalence classes. */
+# ifdef _LIBC
+  int32_t *equiv_classes;
+# endif
+
+  /* Range expressions. */
+# ifdef _LIBC
+  uint32_t *range_starts;
+  uint32_t *range_ends;
+# else /* not _LIBC */
+  wchar_t *range_starts;
+  wchar_t *range_ends;
+# endif /* not _LIBC */
+
+  /* Character classes. */
+  wctype_t *char_classes;
+
+  /* If this character set is the non-matching list.  */
+  unsigned int non_match : 1;
+
+  /* # of multibyte characters.  */
+  Idx nmbchars;
+
+  /* # of collating symbols.  */
+  Idx ncoll_syms;
+
+  /* # of equivalence classes. */
+  Idx nequiv_classes;
+
+  /* # of range expressions. */
+  Idx nranges;
+
+  /* # of character classes. */
+  Idx nchar_classes;
+} re_charset_t;
+#endif /* RE_ENABLE_I18N */
+
+typedef struct
+{
+  union
+  {
+    unsigned char c;		/* for CHARACTER */
+    re_bitset_ptr_t sbcset;	/* for SIMPLE_BRACKET */
+#ifdef RE_ENABLE_I18N
+    re_charset_t *mbcset;	/* for COMPLEX_BRACKET */
+#endif /* RE_ENABLE_I18N */
+    Idx idx;			/* for BACK_REF */
+    re_context_type ctx_type;	/* for ANCHOR */
+  } opr;
+#if __GNUC__ >= 2
+  re_token_type_t type : 8;
+#else
+  re_token_type_t type;
+#endif
+  unsigned int constraint : 10;	/* context constraint */
+  unsigned int duplicated : 1;
+  unsigned int opt_subexp : 1;
+#ifdef RE_ENABLE_I18N
+  unsigned int accept_mb : 1;
+  /* These 2 bits can be moved into the union if needed (e.g. if running out
+     of bits; move opr.c to opr.c.c and move the flags to opr.c.flags).  */
+  unsigned int mb_partial : 1;
+#endif
+  unsigned int word_char : 1;
+} re_token_t;
+
+#define IS_EPSILON_NODE(type) ((type) & EPSILON_BIT)
+
+struct re_string_t
+{
+  /* Indicate the raw buffer which is the original string passed as an
+     argument of regexec(), re_search(), etc..  */
+  const unsigned char *raw_mbs;
+  /* Store the multibyte string.  In case of "case insensitive mode" like
+     REG_ICASE, upper cases of the string are stored, otherwise MBS points
+     the same address that RAW_MBS points.  */
+  unsigned char *mbs;
+#ifdef RE_ENABLE_I18N
+  /* Store the wide character string which is corresponding to MBS.  */
+  wint_t *wcs;
+  Idx *offsets;
+  mbstate_t cur_state;
+#endif
+  /* Index in RAW_MBS.  Each character mbs[i] corresponds to
+     raw_mbs[raw_mbs_idx + i].  */
+  Idx raw_mbs_idx;
+  /* The length of the valid characters in the buffers.  */
+  Idx valid_len;
+  /* The corresponding number of bytes in raw_mbs array.  */
+  Idx valid_raw_len;
+  /* The length of the buffers MBS and WCS.  */
+  Idx bufs_len;
+  /* The index in MBS, which is updated by re_string_fetch_byte.  */
+  Idx cur_idx;
+  /* length of RAW_MBS array.  */
+  Idx raw_len;
+  /* This is RAW_LEN - RAW_MBS_IDX + VALID_LEN - VALID_RAW_LEN.  */
+  Idx len;
+  /* End of the buffer may be shorter than its length in the cases such
+     as re_match_2, re_search_2.  Then, we use STOP for end of the buffer
+     instead of LEN.  */
+  Idx raw_stop;
+  /* This is RAW_STOP - RAW_MBS_IDX adjusted through OFFSETS.  */
+  Idx stop;
+
+  /* The context of mbs[0].  We store the context independently, since
+     the context of mbs[0] may be different from raw_mbs[0], which is
+     the beginning of the input string.  */
+  unsigned int tip_context;
+  /* The translation passed as a part of an argument of re_compile_pattern.  */
+  RE_TRANSLATE_TYPE trans;
+  /* Copy of re_dfa_t's word_char.  */
+  re_const_bitset_ptr_t word_char;
+  /* true if REG_ICASE.  */
+  unsigned char icase;
+  unsigned char is_utf8;
+  unsigned char map_notascii;
+  unsigned char mbs_allocated;
+  unsigned char offsets_needed;
+  unsigned char newline_anchor;
+  unsigned char word_ops_used;
+  int mb_cur_max;
+};
+typedef struct re_string_t re_string_t;
+
+
+struct re_dfa_t;
+typedef struct re_dfa_t re_dfa_t;
+
+#ifndef _LIBC
+# ifdef __i386__
+#  define internal_function   __attribute ((regparm (3), stdcall))
+# else
+#  define internal_function
+# endif
+#endif
+
+static reg_errcode_t re_string_realloc_buffers (re_string_t *pstr,
+						Idx new_buf_len)
+     internal_function;
+#ifdef RE_ENABLE_I18N
+static void build_wcs_buffer (re_string_t *pstr) internal_function;
+static reg_errcode_t build_wcs_upper_buffer (re_string_t *pstr)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static void build_upper_buffer (re_string_t *pstr) internal_function;
+static void re_string_translate_buffer (re_string_t *pstr) internal_function;
+static unsigned int re_string_context_at (const re_string_t *input, Idx idx,
+					  int eflags)
+     internal_function __attribute ((pure));
+#define re_string_peek_byte(pstr, offset) \
+  ((pstr)->mbs[(pstr)->cur_idx + offset])
+#define re_string_fetch_byte(pstr) \
+  ((pstr)->mbs[(pstr)->cur_idx++])
+#define re_string_first_byte(pstr, idx) \
+  ((idx) == (pstr)->valid_len || (pstr)->wcs[idx] != WEOF)
+#define re_string_is_single_byte_char(pstr, idx) \
+  ((pstr)->wcs[idx] != WEOF && ((pstr)->valid_len == (idx) + 1 \
+				|| (pstr)->wcs[(idx) + 1] != WEOF))
+#define re_string_eoi(pstr) ((pstr)->stop <= (pstr)->cur_idx)
+#define re_string_cur_idx(pstr) ((pstr)->cur_idx)
+#define re_string_get_buffer(pstr) ((pstr)->mbs)
+#define re_string_length(pstr) ((pstr)->len)
+#define re_string_byte_at(pstr,idx) ((pstr)->mbs[idx])
+#define re_string_skip_bytes(pstr,idx) ((pstr)->cur_idx += (idx))
+#define re_string_set_index(pstr,idx) ((pstr)->cur_idx = (idx))
+
+#include <alloca.h>
+
+#ifndef _LIBC
+# if HAVE_ALLOCA
+/* The OS usually guarantees only one guard page at the bottom of the stack,
+   and a page size can be as small as 4096 bytes.  So we cannot safely
+   allocate anything larger than 4096 bytes.  Also care for the possibility
+   of a few compiler-allocated temporary stack slots.  */
+#  define __libc_use_alloca(n) ((n) < 4032)
+# else
+/* alloca is implemented with malloc, so just use malloc.  */
+#  define __libc_use_alloca(n) 0
+# endif
+#endif
+
+#ifndef MAX
+# define MAX(a,b) ((a) < (b) ? (b) : (a))
+#endif
+
+#define re_malloc(t,n) ((t *) malloc ((n) * sizeof (t)))
+#define re_realloc(p,t,n) ((t *) realloc (p, (n) * sizeof (t)))
+#define re_free(p) free (p)
+
+struct bin_tree_t
+{
+  struct bin_tree_t *parent;
+  struct bin_tree_t *left;
+  struct bin_tree_t *right;
+  struct bin_tree_t *first;
+  struct bin_tree_t *next;
+
+  re_token_t token;
+
+  /* `node_idx' is the index in dfa->nodes, if `type' == 0.
+     Otherwise `type' indicate the type of this node.  */
+  Idx node_idx;
+};
+typedef struct bin_tree_t bin_tree_t;
+
+#define BIN_TREE_STORAGE_SIZE \
+  ((1024 - sizeof (void *)) / sizeof (bin_tree_t))
+
+struct bin_tree_storage_t
+{
+  struct bin_tree_storage_t *next;
+  bin_tree_t data[BIN_TREE_STORAGE_SIZE];
+};
+typedef struct bin_tree_storage_t bin_tree_storage_t;
+
+#define CONTEXT_WORD 1
+#define CONTEXT_NEWLINE (CONTEXT_WORD << 1)
+#define CONTEXT_BEGBUF (CONTEXT_NEWLINE << 1)
+#define CONTEXT_ENDBUF (CONTEXT_BEGBUF << 1)
+
+#define IS_WORD_CONTEXT(c) ((c) & CONTEXT_WORD)
+#define IS_NEWLINE_CONTEXT(c) ((c) & CONTEXT_NEWLINE)
+#define IS_BEGBUF_CONTEXT(c) ((c) & CONTEXT_BEGBUF)
+#define IS_ENDBUF_CONTEXT(c) ((c) & CONTEXT_ENDBUF)
+#define IS_ORDINARY_CONTEXT(c) ((c) == 0)
+
+#define IS_WORD_CHAR(ch) (isalnum (ch) || (ch) == '_')
+#define IS_NEWLINE(ch) ((ch) == NEWLINE_CHAR)
+#define IS_WIDE_WORD_CHAR(ch) (iswalnum (ch) || (ch) == L'_')
+#define IS_WIDE_NEWLINE(ch) ((ch) == WIDE_NEWLINE_CHAR)
+
+#define NOT_SATISFY_PREV_CONSTRAINT(constraint,context) \
+ ((((constraint) & PREV_WORD_CONSTRAINT) && !IS_WORD_CONTEXT (context)) \
+  || ((constraint & PREV_NOTWORD_CONSTRAINT) && IS_WORD_CONTEXT (context)) \
+  || ((constraint & PREV_NEWLINE_CONSTRAINT) && !IS_NEWLINE_CONTEXT (context))\
+  || ((constraint & PREV_BEGBUF_CONSTRAINT) && !IS_BEGBUF_CONTEXT (context)))
+
+#define NOT_SATISFY_NEXT_CONSTRAINT(constraint,context) \
+ ((((constraint) & NEXT_WORD_CONSTRAINT) && !IS_WORD_CONTEXT (context)) \
+  || (((constraint) & NEXT_NOTWORD_CONSTRAINT) && IS_WORD_CONTEXT (context)) \
+  || (((constraint) & NEXT_NEWLINE_CONSTRAINT) && !IS_NEWLINE_CONTEXT (context)) \
+  || (((constraint) & NEXT_ENDBUF_CONSTRAINT) && !IS_ENDBUF_CONTEXT (context)))
+
+struct re_dfastate_t
+{
+  re_hashval_t hash;
+  re_node_set nodes;
+  re_node_set non_eps_nodes;
+  re_node_set inveclosure;
+  re_node_set *entrance_nodes;
+  struct re_dfastate_t **trtable, **word_trtable;
+  unsigned int context : 4;
+  unsigned int halt : 1;
+  /* If this state can accept `multi byte'.
+     Note that we refer to multibyte characters, and multi character
+     collating elements as `multi byte'.  */
+  unsigned int accept_mb : 1;
+  /* If this state has backreference node(s).  */
+  unsigned int has_backref : 1;
+  unsigned int has_constraint : 1;
+};
+typedef struct re_dfastate_t re_dfastate_t;
+
+struct re_state_table_entry
+{
+  Idx num;
+  Idx alloc;
+  re_dfastate_t **array;
+};
+
+/* Array type used in re_sub_match_last_t and re_sub_match_top_t.  */
+
+typedef struct
+{
+  Idx next_idx;
+  Idx alloc;
+  re_dfastate_t **array;
+} state_array_t;
+
+/* Store information about the node NODE whose type is OP_CLOSE_SUBEXP.  */
+
+typedef struct
+{
+  Idx node;
+  Idx str_idx; /* The position NODE match at.  */
+  state_array_t path;
+} re_sub_match_last_t;
+
+/* Store information about the node NODE whose type is OP_OPEN_SUBEXP.
+   And information about the node, whose type is OP_CLOSE_SUBEXP,
+   corresponding to NODE is stored in LASTS.  */
+
+typedef struct
+{
+  Idx str_idx;
+  Idx node;
+  state_array_t *path;
+  Idx alasts; /* Allocation size of LASTS.  */
+  Idx nlasts; /* The number of LASTS.  */
+  re_sub_match_last_t **lasts;
+} re_sub_match_top_t;
+
+struct re_backref_cache_entry
+{
+  Idx node;
+  Idx str_idx;
+  Idx subexp_from;
+  Idx subexp_to;
+  char more;
+  char unused;
+  unsigned short int eps_reachable_subexps_map;
+};
+
+typedef struct
+{
+  /* The string object corresponding to the input string.  */
+  re_string_t input;
+#if defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
+  const re_dfa_t *const dfa;
+#else
+  const re_dfa_t *dfa;
+#endif
+  /* EFLAGS of the argument of regexec.  */
+  int eflags;
+  /* Where the matching ends.  */
+  Idx match_last;
+  Idx last_node;
+  /* The state log used by the matcher.  */
+  re_dfastate_t **state_log;
+  Idx state_log_top;
+  /* Back reference cache.  */
+  Idx nbkref_ents;
+  Idx abkref_ents;
+  struct re_backref_cache_entry *bkref_ents;
+  int max_mb_elem_len;
+  Idx nsub_tops;
+  Idx asub_tops;
+  re_sub_match_top_t **sub_tops;
+} re_match_context_t;
+
+typedef struct
+{
+  re_dfastate_t **sifted_states;
+  re_dfastate_t **limited_states;
+  Idx last_node;
+  Idx last_str_idx;
+  re_node_set limits;
+} re_sift_context_t;
+
+struct re_fail_stack_ent_t
+{
+  Idx idx;
+  Idx node;
+  regmatch_t *regs;
+  re_node_set eps_via_nodes;
+};
+
+struct re_fail_stack_t
+{
+  Idx num;
+  Idx alloc;
+  struct re_fail_stack_ent_t *stack;
+};
+
+struct re_dfa_t
+{
+  re_token_t *nodes;
+  size_t nodes_alloc;
+  size_t nodes_len;
+  Idx *nexts;
+  Idx *org_indices;
+  re_node_set *edests;
+  re_node_set *eclosures;
+  re_node_set *inveclosures;
+  struct re_state_table_entry *state_table;
+  re_dfastate_t *init_state;
+  re_dfastate_t *init_state_word;
+  re_dfastate_t *init_state_nl;
+  re_dfastate_t *init_state_begbuf;
+  bin_tree_t *str_tree;
+  bin_tree_storage_t *str_tree_storage;
+  re_bitset_ptr_t sb_char;
+  int str_tree_storage_idx;
+
+  /* number of subexpressions `re_nsub' is in regex_t.  */
+  re_hashval_t state_hash_mask;
+  Idx init_node;
+  Idx nbackref; /* The number of backreference in this dfa.  */
+
+  /* Bitmap expressing which backreference is used.  */
+  bitset_word_t used_bkref_map;
+  bitset_word_t completed_bkref_map;
+
+  unsigned int has_plural_match : 1;
+  /* If this dfa has "multibyte node", which is a backreference or
+     a node which can accept multibyte character or multi character
+     collating element.  */
+  unsigned int has_mb_node : 1;
+  unsigned int is_utf8 : 1;
+  unsigned int map_notascii : 1;
+  unsigned int word_ops_used : 1;
+  int mb_cur_max;
+  bitset_t word_char;
+  reg_syntax_t syntax;
+  Idx *subexp_map;
+#ifdef DEBUG
+  char* re_str;
+#endif
+#ifdef _LIBC
+  __libc_lock_define (, lock)
+#endif
+};
+
+#define re_node_set_init_empty(set) memset (set, '\0', sizeof (re_node_set))
+#define re_node_set_remove(set,id) \
+  (re_node_set_remove_at (set, re_node_set_contains (set, id) - 1))
+#define re_node_set_empty(p) ((p)->nelem = 0)
+#define re_node_set_free(set) re_free ((set)->elems)
+
+
+typedef enum
+{
+  SB_CHAR,
+  MB_CHAR,
+  EQUIV_CLASS,
+  COLL_SYM,
+  CHAR_CLASS
+} bracket_elem_type;
+
+typedef struct
+{
+  bracket_elem_type type;
+  union
+  {
+    unsigned char ch;
+    unsigned char *name;
+    wchar_t wch;
+  } opr;
+} bracket_elem_t;
+
+
+/* Inline functions for bitset_t operation.  */
+
+static inline void
+bitset_set (bitset_t set, Idx i)
+{
+  set[i / BITSET_WORD_BITS] |= (bitset_word_t) 1 << i % BITSET_WORD_BITS;
+}
+
+static inline void
+bitset_clear (bitset_t set, Idx i)
+{
+  set[i / BITSET_WORD_BITS] &= ~ ((bitset_word_t) 1 << i % BITSET_WORD_BITS);
+}
+
+static inline bool
+bitset_contain (const bitset_t set, Idx i)
+{
+  return (set[i / BITSET_WORD_BITS] >> i % BITSET_WORD_BITS) & 1;
+}
+
+static inline void
+bitset_empty (bitset_t set)
+{
+  memset (set, '\0', sizeof (bitset_t));
+}
+
+static inline void
+bitset_set_all (bitset_t set)
+{
+  memset (set, -1, sizeof (bitset_word_t) * (SBC_MAX / BITSET_WORD_BITS));
+  if (SBC_MAX % BITSET_WORD_BITS != 0)
+    set[BITSET_WORDS - 1] =
+      ((bitset_word_t) 1 << SBC_MAX % BITSET_WORD_BITS) - 1;
+}
+
+static inline void
+bitset_copy (bitset_t dest, const bitset_t src)
+{
+  memcpy (dest, src, sizeof (bitset_t));
+}
+
+static inline void
+bitset_not (bitset_t set)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < SBC_MAX / BITSET_WORD_BITS; ++bitset_i)
+    set[bitset_i] = ~set[bitset_i];
+  if (SBC_MAX % BITSET_WORD_BITS != 0)
+    set[BITSET_WORDS - 1] =
+      ((((bitset_word_t) 1 << SBC_MAX % BITSET_WORD_BITS) - 1)
+       & ~set[BITSET_WORDS - 1]);
+}
+
+static inline void
+bitset_merge (bitset_t dest, const bitset_t src)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < BITSET_WORDS; ++bitset_i)
+    dest[bitset_i] |= src[bitset_i];
+}
+
+static inline void
+bitset_mask (bitset_t dest, const bitset_t src)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < BITSET_WORDS; ++bitset_i)
+    dest[bitset_i] &= src[bitset_i];
+}
+
+#ifdef RE_ENABLE_I18N
+/* Inline functions for re_string.  */
+static inline int
+internal_function __attribute ((pure))
+re_string_char_size_at (const re_string_t *pstr, Idx idx)
+{
+  int byte_idx;
+  if (pstr->mb_cur_max == 1)
+    return 1;
+  for (byte_idx = 1; idx + byte_idx < pstr->valid_len; ++byte_idx)
+    if (pstr->wcs[idx + byte_idx] != WEOF)
+      break;
+  return byte_idx;
+}
+
+static inline wint_t
+internal_function __attribute ((pure))
+re_string_wchar_at (const re_string_t *pstr, Idx idx)
+{
+  if (pstr->mb_cur_max == 1)
+    return (wint_t) pstr->mbs[idx];
+  return (wint_t) pstr->wcs[idx];
+}
+
+static int
+internal_function __attribute ((pure))
+re_string_elem_size_at (const re_string_t *pstr, Idx idx)
+{
+# ifdef _LIBC
+  const unsigned char *p, *extra;
+  const int32_t *table, *indirect;
+  int32_t tmp;
+#  include <locale/weight.h>
+  uint_fast32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+
+  if (nrules != 0)
+    {
+      table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+      extra = (const unsigned char *)
+	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAMB);
+      indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+						_NL_COLLATE_INDIRECTMB);
+      p = pstr->mbs + idx;
+      tmp = findidx (&p);
+      return p - pstr->mbs - idx;
+    }
+  else
+# endif /* _LIBC */
+    return 1;
+}
+#endif /* RE_ENABLE_I18N */
+
+#endif /*  _REGEX_INTERNAL_H */
diff --git a/src/bin/m4/lib/regexec.c b/src/bin/m4/lib/regexec.c
new file mode 100644
index 0000000000..84c3aed634
--- /dev/null
+++ b/src/bin/m4/lib/regexec.c
@@ -0,0 +1,4398 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+static reg_errcode_t match_ctx_init (re_match_context_t *cache, int eflags,
+				     Idx n) internal_function;
+static void match_ctx_clean (re_match_context_t *mctx) internal_function;
+static void match_ctx_free (re_match_context_t *cache) internal_function;
+static reg_errcode_t match_ctx_add_entry (re_match_context_t *cache, Idx node,
+					  Idx str_idx, Idx from, Idx to)
+     internal_function;
+static Idx search_cur_bkref_entry (const re_match_context_t *mctx, Idx str_idx)
+     internal_function;
+static reg_errcode_t match_ctx_add_subtop (re_match_context_t *mctx, Idx node,
+					   Idx str_idx) internal_function;
+static re_sub_match_last_t * match_ctx_add_sublast (re_sub_match_top_t *subtop,
+						    Idx node, Idx str_idx)
+     internal_function;
+static void sift_ctx_init (re_sift_context_t *sctx, re_dfastate_t **sifted_sts,
+			   re_dfastate_t **limited_sts, Idx last_node,
+			   Idx last_str_idx)
+     internal_function;
+static reg_errcode_t re_search_internal (const regex_t *preg,
+					 const char *string, Idx length,
+					 Idx start, Idx last_start, Idx stop,
+					 size_t nmatch, regmatch_t pmatch[],
+					 int eflags) internal_function;
+static regoff_t re_search_2_stub (struct re_pattern_buffer *bufp,
+				  const char *string1, Idx length1,
+				  const char *string2, Idx length2,
+				  Idx start, regoff_t range,
+				  struct re_registers *regs,
+				  Idx stop, bool ret_len) internal_function;
+static regoff_t re_search_stub (struct re_pattern_buffer *bufp,
+				const char *string, Idx length, Idx start,
+				regoff_t range, Idx stop,
+				struct re_registers *regs,
+				bool ret_len) internal_function;
+static unsigned int re_copy_regs (struct re_registers *regs, regmatch_t *pmatch,
+				  Idx nregs, int regs_allocated)
+     internal_function;
+static reg_errcode_t prune_impossible_nodes (re_match_context_t *mctx)
+     internal_function;
+static Idx check_matching (re_match_context_t *mctx, bool fl_longest_match,
+			   Idx *p_match_first) internal_function;
+static Idx check_halt_state_context (const re_match_context_t *mctx,
+				     const re_dfastate_t *state, Idx idx)
+     internal_function;
+static void update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
+			 regmatch_t *prev_idx_match, Idx cur_node,
+			 Idx cur_idx, Idx nmatch) internal_function;
+static reg_errcode_t push_fail_stack (struct re_fail_stack_t *fs,
+				      Idx str_idx, Idx dest_node, Idx nregs,
+				      regmatch_t *regs,
+				      re_node_set *eps_via_nodes)
+     internal_function;
+static reg_errcode_t set_regs (const regex_t *preg,
+			       const re_match_context_t *mctx,
+			       size_t nmatch, regmatch_t *pmatch,
+			       bool fl_backtrack) internal_function;
+static reg_errcode_t free_fail_stack_return (struct re_fail_stack_t *fs)
+     internal_function;
+
+#ifdef RE_ENABLE_I18N
+static int sift_states_iter_mb (const re_match_context_t *mctx,
+				re_sift_context_t *sctx,
+				Idx node_idx, Idx str_idx, Idx max_str_idx)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static reg_errcode_t sift_states_backward (const re_match_context_t *mctx,
+					   re_sift_context_t *sctx)
+     internal_function;
+static reg_errcode_t build_sifted_states (const re_match_context_t *mctx,
+					  re_sift_context_t *sctx, Idx str_idx,
+					  re_node_set *cur_dest)
+     internal_function;
+static reg_errcode_t update_cur_sifted_state (const re_match_context_t *mctx,
+					      re_sift_context_t *sctx,
+					      Idx str_idx,
+					      re_node_set *dest_nodes)
+     internal_function;
+static reg_errcode_t add_epsilon_src_nodes (const re_dfa_t *dfa,
+					    re_node_set *dest_nodes,
+					    const re_node_set *candidates)
+     internal_function;
+static bool check_dst_limits (const re_match_context_t *mctx,
+			      const re_node_set *limits,
+			      Idx dst_node, Idx dst_idx, Idx src_node,
+			      Idx src_idx) internal_function;
+static int check_dst_limits_calc_pos_1 (const re_match_context_t *mctx,
+					int boundaries, Idx subexp_idx,
+					Idx from_node, Idx bkref_idx)
+     internal_function;
+static int check_dst_limits_calc_pos (const re_match_context_t *mctx,
+				      Idx limit, Idx subexp_idx,
+				      Idx node, Idx str_idx,
+				      Idx bkref_idx) internal_function;
+static reg_errcode_t check_subexp_limits (const re_dfa_t *dfa,
+					  re_node_set *dest_nodes,
+					  const re_node_set *candidates,
+					  re_node_set *limits,
+					  struct re_backref_cache_entry *bkref_ents,
+					  Idx str_idx) internal_function;
+static reg_errcode_t sift_states_bkref (const re_match_context_t *mctx,
+					re_sift_context_t *sctx,
+					Idx str_idx, const re_node_set *candidates)
+     internal_function;
+static reg_errcode_t merge_state_array (const re_dfa_t *dfa,
+					re_dfastate_t **dst,
+					re_dfastate_t **src, Idx num)
+     internal_function;
+static re_dfastate_t *find_recover_state (reg_errcode_t *err,
+					 re_match_context_t *mctx) internal_function;
+static re_dfastate_t *transit_state (reg_errcode_t *err,
+				     re_match_context_t *mctx,
+				     re_dfastate_t *state) internal_function;
+static re_dfastate_t *merge_state_with_log (reg_errcode_t *err,
+					    re_match_context_t *mctx,
+					    re_dfastate_t *next_state)
+     internal_function;
+static reg_errcode_t check_subexp_matching_top (re_match_context_t *mctx,
+						re_node_set *cur_nodes,
+						Idx str_idx) internal_function;
+#if 0
+static re_dfastate_t *transit_state_sb (reg_errcode_t *err,
+					re_match_context_t *mctx,
+					re_dfastate_t *pstate)
+     internal_function;
+#endif
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t transit_state_mb (re_match_context_t *mctx,
+				       re_dfastate_t *pstate)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static reg_errcode_t transit_state_bkref (re_match_context_t *mctx,
+					  const re_node_set *nodes)
+     internal_function;
+static reg_errcode_t get_subexp (re_match_context_t *mctx,
+				 Idx bkref_node, Idx bkref_str_idx)
+     internal_function;
+static reg_errcode_t get_subexp_sub (re_match_context_t *mctx,
+				     const re_sub_match_top_t *sub_top,
+				     re_sub_match_last_t *sub_last,
+				     Idx bkref_node, Idx bkref_str)
+     internal_function;
+static Idx find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes,
+			     Idx subexp_idx, int type) internal_function;
+static reg_errcode_t check_arrival (re_match_context_t *mctx,
+				    state_array_t *path, Idx top_node,
+				    Idx top_str, Idx last_node, Idx last_str,
+				    int type) internal_function;
+static reg_errcode_t check_arrival_add_next_nodes (re_match_context_t *mctx,
+						   Idx str_idx,
+						   re_node_set *cur_nodes,
+						   re_node_set *next_nodes)
+     internal_function;
+static reg_errcode_t check_arrival_expand_ecl (const re_dfa_t *dfa,
+					       re_node_set *cur_nodes,
+					       Idx ex_subexp, int type)
+     internal_function;
+static reg_errcode_t check_arrival_expand_ecl_sub (const re_dfa_t *dfa,
+						   re_node_set *dst_nodes,
+						   Idx target, Idx ex_subexp,
+						   int type) internal_function;
+static reg_errcode_t expand_bkref_cache (re_match_context_t *mctx,
+					 re_node_set *cur_nodes, Idx cur_str,
+					 Idx subexp_num, int type)
+     internal_function;
+static bool build_trtable (const re_dfa_t *dfa,
+			   re_dfastate_t *state) internal_function;
+#ifdef RE_ENABLE_I18N
+static int check_node_accept_bytes (const re_dfa_t *dfa, Idx node_idx,
+				    const re_string_t *input, Idx idx)
+     internal_function;
+# ifdef _LIBC
+static unsigned int find_collation_sequence_value (const unsigned char *mbs,
+						   size_t name_len)
+     internal_function;
+# endif /* _LIBC */
+#endif /* RE_ENABLE_I18N */
+static Idx group_nodes_into_DFAstates (const re_dfa_t *dfa,
+				       const re_dfastate_t *state,
+				       re_node_set *states_node,
+				       bitset_t *states_ch) internal_function;
+static bool check_node_accept (const re_match_context_t *mctx,
+			       const re_token_t *node, Idx idx)
+     internal_function;
+static reg_errcode_t extend_buffers (re_match_context_t *mctx)
+     internal_function;
+
+/* Entry point for POSIX code.  */
+
+/* regexec searches for a given pattern, specified by PREG, in the
+   string STRING.
+
+   If NMATCH is zero or REG_NOSUB was set in the cflags argument to
+   `regcomp', we ignore PMATCH.  Otherwise, we assume PMATCH has at
+   least NMATCH elements, and we set them to the offsets of the
+   corresponding matched substrings.
+
+   EFLAGS specifies `execution flags' which affect matching: if
+   REG_NOTBOL is set, then ^ does not match at the beginning of the
+   string; if REG_NOTEOL is set, then $ does not match at the end.
+
+   We return 0 if we find a match and REG_NOMATCH if not.  */
+
+int
+regexec (preg, string, nmatch, pmatch, eflags)
+    const regex_t *__restrict preg;
+    const char *__restrict string;
+    size_t nmatch;
+    regmatch_t pmatch[];
+    int eflags;
+{
+  reg_errcode_t err;
+  Idx start, length;
+#ifdef _LIBC
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+#endif
+
+  if (eflags & ~(REG_NOTBOL | REG_NOTEOL | REG_STARTEND))
+    return REG_BADPAT;
+
+  if (eflags & REG_STARTEND)
+    {
+      start = pmatch[0].rm_so;
+      length = pmatch[0].rm_eo;
+    }
+  else
+    {
+      start = 0;
+      length = strlen (string);
+    }
+
+  __libc_lock_lock (dfa->lock);
+  if (preg->no_sub)
+    err = re_search_internal (preg, string, length, start, length,
+			      length, 0, NULL, eflags);
+  else
+    err = re_search_internal (preg, string, length, start, length,
+			      length, nmatch, pmatch, eflags);
+  __libc_lock_unlock (dfa->lock);
+  return err != REG_NOERROR;
+}
+
+#ifdef _LIBC
+# include <shlib-compat.h>
+versioned_symbol (libc, __regexec, regexec, GLIBC_2_3_4);
+
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
+__typeof__ (__regexec) __compat_regexec;
+
+int
+attribute_compat_text_section
+__compat_regexec (const regex_t *__restrict preg,
+		  const char *__restrict string, size_t nmatch,
+		  regmatch_t pmatch[], int eflags)
+{
+  return regexec (preg, string, nmatch, pmatch,
+		  eflags & (REG_NOTBOL | REG_NOTEOL));
+}
+compat_symbol (libc, __compat_regexec, regexec, GLIBC_2_0);
+# endif
+#endif
+
+/* Entry points for GNU code.  */
+
+/* re_match, re_search, re_match_2, re_search_2
+
+   The former two functions operate on STRING with length LENGTH,
+   while the later two operate on concatenation of STRING1 and STRING2
+   with lengths LENGTH1 and LENGTH2, respectively.
+
+   re_match() matches the compiled pattern in BUFP against the string,
+   starting at index START.
+
+   re_search() first tries matching at index START, then it tries to match
+   starting from index START + 1, and so on.  The last start position tried
+   is START + RANGE.  (Thus RANGE = 0 forces re_search to operate the same
+   way as re_match().)
+
+   The parameter STOP of re_{match,search}_2 specifies that no match exceeding
+   the first STOP characters of the concatenation of the strings should be
+   concerned.
+
+   If REGS is not NULL, and BUFP->no_sub is not set, the offsets of the match
+   and all groups is stored in REGS.  (For the "_2" variants, the offsets are
+   computed relative to the concatenation, not relative to the individual
+   strings.)
+
+   On success, re_match* functions return the length of the match, re_search*
+   return the position of the start of the match.  Return value -1 means no
+   match was found and -2 indicates an internal error.  */
+
+regoff_t
+re_match (bufp, string, length, start, regs)
+    struct re_pattern_buffer *bufp;
+    const char *string;
+    Idx length, start;
+    struct re_registers *regs;
+{
+  return re_search_stub (bufp, string, length, start, 0, length, regs, true);
+}
+#ifdef _LIBC
+weak_alias (__re_match, re_match)
+#endif
+
+regoff_t
+re_search (bufp, string, length, start, range, regs)
+    struct re_pattern_buffer *bufp;
+    const char *string;
+    Idx length, start;
+    regoff_t range;
+    struct re_registers *regs;
+{
+  return re_search_stub (bufp, string, length, start, range, length, regs,
+			 false);
+}
+#ifdef _LIBC
+weak_alias (__re_search, re_search)
+#endif
+
+regoff_t
+re_match_2 (bufp, string1, length1, string2, length2, start, regs, stop)
+    struct re_pattern_buffer *bufp;
+    const char *string1, *string2;
+    Idx length1, length2, start, stop;
+    struct re_registers *regs;
+{
+  return re_search_2_stub (bufp, string1, length1, string2, length2,
+			   start, 0, regs, stop, true);
+}
+#ifdef _LIBC
+weak_alias (__re_match_2, re_match_2)
+#endif
+
+regoff_t
+re_search_2 (bufp, string1, length1, string2, length2, start, range, regs, stop)
+    struct re_pattern_buffer *bufp;
+    const char *string1, *string2;
+    Idx length1, length2, start, stop;
+    regoff_t range;
+    struct re_registers *regs;
+{
+  return re_search_2_stub (bufp, string1, length1, string2, length2,
+			   start, range, regs, stop, false);
+}
+#ifdef _LIBC
+weak_alias (__re_search_2, re_search_2)
+#endif
+
+static regoff_t
+internal_function
+re_search_2_stub (struct re_pattern_buffer *bufp,
+		  const char *string1, Idx length1,
+		  const char *string2, Idx length2,
+		  Idx start, regoff_t range, struct re_registers *regs,
+		  Idx stop, bool ret_len)
+{
+  const char *str;
+  regoff_t rval;
+  Idx len = length1 + length2;
+  char *s = NULL;
+
+  if (BE (length1 < 0 || length2 < 0 || stop < 0 || len < length1, 0))
+    return -2;
+
+  /* Concatenate the strings.  */
+  if (length2 > 0)
+    if (length1 > 0)
+      {
+	s = re_malloc (char, len);
+
+	if (BE (s == NULL, 0))
+	  return -2;
+#ifdef _LIBC
+	memcpy (__mempcpy (s, string1, length1), string2, length2);
+#else
+	memcpy (s, string1, length1);
+	memcpy (s + length1, string2, length2);
+#endif
+	str = s;
+      }
+    else
+      str = string2;
+  else
+    str = string1;
+
+  rval = re_search_stub (bufp, str, len, start, range, stop, regs,
+			 ret_len);
+  re_free (s);
+  return rval;
+}
+
+/* The parameters have the same meaning as those of re_search.
+   Additional parameters:
+   If RET_LEN is true the length of the match is returned (re_match style);
+   otherwise the position of the match is returned.  */
+
+static regoff_t
+internal_function
+re_search_stub (struct re_pattern_buffer *bufp,
+		const char *string, Idx length,
+		Idx start, regoff_t range, Idx stop, struct re_registers *regs,
+		bool ret_len)
+{
+  reg_errcode_t result;
+  regmatch_t *pmatch;
+  Idx nregs;
+  regoff_t rval;
+  int eflags = 0;
+#ifdef _LIBC
+  re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+#endif
+  Idx last_start = start + range;
+
+  /* Check for out-of-range.  */
+  if (BE (start < 0 || start > length, 0))
+    return -1;
+  if (BE (length < last_start || (0 <= range && last_start < start), 0))
+    last_start = length;
+  else if (BE (last_start < 0 || (range < 0 && start <= last_start), 0))
+    last_start = 0;
+
+  __libc_lock_lock (dfa->lock);
+
+  eflags |= (bufp->not_bol) ? REG_NOTBOL : 0;
+  eflags |= (bufp->not_eol) ? REG_NOTEOL : 0;
+
+  /* Compile fastmap if we haven't yet.  */
+  if (start < last_start && bufp->fastmap != NULL && !bufp->fastmap_accurate)
+    re_compile_fastmap (bufp);
+
+  if (BE (bufp->no_sub, 0))
+    regs = NULL;
+
+  /* We need at least 1 register.  */
+  if (regs == NULL)
+    nregs = 1;
+  else if (BE (bufp->regs_allocated == REGS_FIXED
+	       && regs->num_regs <= bufp->re_nsub, 0))
+    {
+      nregs = regs->num_regs;
+      if (BE (nregs < 1, 0))
+	{
+	  /* Nothing can be copied to regs.  */
+	  regs = NULL;
+	  nregs = 1;
+	}
+    }
+  else
+    nregs = bufp->re_nsub + 1;
+  pmatch = re_malloc (regmatch_t, nregs);
+  if (BE (pmatch == NULL, 0))
+    {
+      rval = -2;
+      goto out;
+    }
+
+  result = re_search_internal (bufp, string, length, start, last_start, stop,
+			       nregs, pmatch, eflags);
+
+  rval = 0;
+
+  /* I hope we needn't fill ther regs with -1's when no match was found.  */
+  if (result != REG_NOERROR)
+    rval = -1;
+  else if (regs != NULL)
+    {
+      /* If caller wants register contents data back, copy them.  */
+      bufp->regs_allocated = re_copy_regs (regs, pmatch, nregs,
+					   bufp->regs_allocated);
+      if (BE (bufp->regs_allocated == REGS_UNALLOCATED, 0))
+	rval = -2;
+    }
+
+  if (BE (rval == 0, 1))
+    {
+      if (ret_len)
+	{
+	  assert (pmatch[0].rm_so == start);
+	  rval = pmatch[0].rm_eo - start;
+	}
+      else
+	rval = pmatch[0].rm_so;
+    }
+  re_free (pmatch);
+ out:
+  __libc_lock_unlock (dfa->lock);
+  return rval;
+}
+
+static unsigned int
+internal_function
+re_copy_regs (struct re_registers *regs, regmatch_t *pmatch, Idx nregs,
+	      int regs_allocated)
+{
+  int rval = REGS_REALLOCATE;
+  Idx i;
+  Idx need_regs = nregs + 1;
+  /* We need one extra element beyond `num_regs' for the `-1' marker GNU code
+     uses.  */
+
+  /* Have the register data arrays been allocated?  */
+  if (regs_allocated == REGS_UNALLOCATED)
+    { /* No.  So allocate them with malloc.  */
+      regs->start = re_malloc (regoff_t, need_regs);
+      if (BE (regs->start == NULL, 0))
+	return REGS_UNALLOCATED;
+      regs->end = re_malloc (regoff_t, need_regs);
+      if (BE (regs->end == NULL, 0))
+	{
+	  re_free (regs->start);
+	  return REGS_UNALLOCATED;
+	}
+      regs->num_regs = need_regs;
+    }
+  else if (regs_allocated == REGS_REALLOCATE)
+    { /* Yes.  If we need more elements than were already
+	 allocated, reallocate them.  If we need fewer, just
+	 leave it alone.  */
+      if (BE (need_regs > regs->num_regs, 0))
+	{
+	  regoff_t *new_start = re_realloc (regs->start, regoff_t, need_regs);
+	  regoff_t *new_end;
+	  if (BE (new_start == NULL, 0))
+	    return REGS_UNALLOCATED;
+	  new_end = re_realloc (regs->end, regoff_t, need_regs);
+	  if (BE (new_end == NULL, 0))
+	    {
+	      re_free (new_start);
+	      return REGS_UNALLOCATED;
+	    }
+	  regs->start = new_start;
+	  regs->end = new_end;
+	  regs->num_regs = need_regs;
+	}
+    }
+  else
+    {
+      assert (regs_allocated == REGS_FIXED);
+      /* This function may not be called with REGS_FIXED and nregs too big.  */
+      assert (regs->num_regs >= nregs);
+      rval = REGS_FIXED;
+    }
+
+  /* Copy the regs.  */
+  for (i = 0; i < nregs; ++i)
+    {
+      regs->start[i] = pmatch[i].rm_so;
+      regs->end[i] = pmatch[i].rm_eo;
+    }
+  for ( ; i < regs->num_regs; ++i)
+    regs->start[i] = regs->end[i] = -1;
+
+  return rval;
+}
+
+/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+   ENDS.  Subsequent matches using PATTERN_BUFFER and REGS will use
+   this memory for recording register information.  STARTS and ENDS
+   must be allocated using the malloc library routine, and must each
+   be at least NUM_REGS * sizeof (regoff_t) bytes long.
+
+   If NUM_REGS == 0, then subsequent matches should allocate their own
+   register data.
+
+   Unless this function is called, the first search or match using
+   PATTERN_BUFFER will allocate its own register data, without
+   freeing the old data.  */
+
+void
+re_set_registers (bufp, regs, num_regs, starts, ends)
+    struct re_pattern_buffer *bufp;
+    struct re_registers *regs;
+    __re_size_t num_regs;
+    regoff_t *starts, *ends;
+{
+  if (num_regs)
+    {
+      bufp->regs_allocated = REGS_REALLOCATE;
+      regs->num_regs = num_regs;
+      regs->start = starts;
+      regs->end = ends;
+    }
+  else
+    {
+      bufp->regs_allocated = REGS_UNALLOCATED;
+      regs->num_regs = 0;
+      regs->start = regs->end = NULL;
+    }
+}
+#ifdef _LIBC
+weak_alias (__re_set_registers, re_set_registers)
+#endif
+
+/* Entry points compatible with 4.2 BSD regex library.  We don't define
+   them unless specifically requested.  */
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+int
+# ifdef _LIBC
+weak_function
+# endif
+re_exec (s)
+     const char *s;
+{
+  return 0 == regexec (&re_comp_buf, s, 0, NULL, 0);
+}
+#endif /* _REGEX_RE_COMP */
+
+/* Internal entry point.  */
+
+/* Searches for a compiled pattern PREG in the string STRING, whose
+   length is LENGTH.  NMATCH, PMATCH, and EFLAGS have the same
+   meaning as with regexec.  LAST_START is START + RANGE, where
+   START and RANGE have the same meaning as with re_search.
+   Return REG_NOERROR if we find a match, and REG_NOMATCH if not,
+   otherwise return the error code.
+   Note: We assume front end functions already check ranges.
+   (0 <= LAST_START && LAST_START <= LENGTH)  */
+
+static reg_errcode_t
+internal_function
+re_search_internal (const regex_t *preg,
+		    const char *string, Idx length,
+		    Idx start, Idx last_start, Idx stop,
+		    size_t nmatch, regmatch_t pmatch[],
+		    int eflags)
+{
+  reg_errcode_t err;
+  const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer;
+  Idx left_lim, right_lim;
+  int incr;
+  bool fl_longest_match;
+  int match_kind;
+  Idx match_first;
+  Idx match_last = REG_MISSING;
+  Idx extra_nmatch;
+  bool sb;
+  int ch;
+#if defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
+  re_match_context_t mctx = { .dfa = dfa };
+#else
+  re_match_context_t mctx;
+#endif
+  char *fastmap = ((preg->fastmap != NULL && preg->fastmap_accurate
+		    && start != last_start && !preg->can_be_null)
+		   ? preg->fastmap : NULL);
+  RE_TRANSLATE_TYPE t = preg->translate;
+
+#if !(defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
+  memset (&mctx, '\0', sizeof (re_match_context_t));
+  mctx.dfa = dfa;
+#endif
+
+  extra_nmatch = (nmatch > preg->re_nsub) ? nmatch - (preg->re_nsub + 1) : 0;
+  nmatch -= extra_nmatch;
+
+  /* Check if the DFA haven't been compiled.  */
+  if (BE (preg->used == 0 || dfa->init_state == NULL
+	  || dfa->init_state_word == NULL || dfa->init_state_nl == NULL
+	  || dfa->init_state_begbuf == NULL, 0))
+    return REG_NOMATCH;
+
+#ifdef DEBUG
+  /* We assume front-end functions already check them.  */
+  assert (0 <= last_start && last_start <= length);
+#endif
+
+  /* If initial states with non-begbuf contexts have no elements,
+     the regex must be anchored.  If preg->newline_anchor is set,
+     we'll never use init_state_nl, so do not check it.  */
+  if (dfa->init_state->nodes.nelem == 0
+      && dfa->init_state_word->nodes.nelem == 0
+      && (dfa->init_state_nl->nodes.nelem == 0
+	  || !preg->newline_anchor))
+    {
+      if (start != 0 && last_start != 0)
+        return REG_NOMATCH;
+      start = last_start = 0;
+    }
+
+  /* We must check the longest matching, if nmatch > 0.  */
+  fl_longest_match = (nmatch != 0 || dfa->nbackref);
+
+  err = re_string_allocate (&mctx.input, string, length, dfa->nodes_len + 1,
+			    preg->translate, preg->syntax & RE_ICASE, dfa);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+  mctx.input.stop = stop;
+  mctx.input.raw_stop = stop;
+  mctx.input.newline_anchor = preg->newline_anchor;
+
+  err = match_ctx_init (&mctx, eflags, dfa->nbackref * 2);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+
+  /* We will log all the DFA states through which the dfa pass,
+     if nmatch > 1, or this dfa has "multibyte node", which is a
+     back-reference or a node which can accept multibyte character or
+     multi character collating element.  */
+  if (nmatch > 1 || dfa->has_mb_node)
+    {
+      /* Avoid overflow.  */
+      if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= mctx.input.bufs_len, 0))
+	{
+	  err = REG_ESPACE;
+	  goto free_return;
+	}
+
+      mctx.state_log = re_malloc (re_dfastate_t *, mctx.input.bufs_len + 1);
+      if (BE (mctx.state_log == NULL, 0))
+	{
+	  err = REG_ESPACE;
+	  goto free_return;
+	}
+    }
+  else
+    mctx.state_log = NULL;
+
+  match_first = start;
+  mctx.input.tip_context = (eflags & REG_NOTBOL) ? CONTEXT_BEGBUF
+			   : CONTEXT_NEWLINE | CONTEXT_BEGBUF;
+
+  /* Check incrementally whether of not the input string match.  */
+  incr = (last_start < start) ? -1 : 1;
+  left_lim = (last_start < start) ? last_start : start;
+  right_lim = (last_start < start) ? start : last_start;
+  sb = dfa->mb_cur_max == 1;
+  match_kind =
+    (fastmap
+     ? ((sb || !(preg->syntax & RE_ICASE || t) ? 4 : 0)
+	| (start <= last_start ? 2 : 0)
+	| (t != NULL ? 1 : 0))
+     : 8);
+
+  for (;; match_first += incr)
+    {
+      err = REG_NOMATCH;
+      if (match_first < left_lim || right_lim < match_first)
+	goto free_return;
+
+      /* Advance as rapidly as possible through the string, until we
+	 find a plausible place to start matching.  This may be done
+	 with varying efficiency, so there are various possibilities:
+	 only the most common of them are specialized, in order to
+	 save on code size.  We use a switch statement for speed.  */
+      switch (match_kind)
+	{
+	case 8:
+	  /* No fastmap.  */
+	  break;
+
+	case 7:
+	  /* Fastmap with single-byte translation, match forward.  */
+	  while (BE (match_first < right_lim, 1)
+		 && !fastmap[t[(unsigned char) string[match_first]]])
+	    ++match_first;
+	  goto forward_match_found_start_or_reached_end;
+
+	case 6:
+	  /* Fastmap without translation, match forward.  */
+	  while (BE (match_first < right_lim, 1)
+		 && !fastmap[(unsigned char) string[match_first]])
+	    ++match_first;
+
+	forward_match_found_start_or_reached_end:
+	  if (BE (match_first == right_lim, 0))
+	    {
+	      ch = match_first >= length
+		       ? 0 : (unsigned char) string[match_first];
+	      if (!fastmap[t ? t[ch] : ch])
+		goto free_return;
+	    }
+	  break;
+
+	case 4:
+	case 5:
+	  /* Fastmap without multi-byte translation, match backwards.  */
+	  while (match_first >= left_lim)
+	    {
+	      ch = match_first >= length
+		       ? 0 : (unsigned char) string[match_first];
+	      if (fastmap[t ? t[ch] : ch])
+		break;
+	      --match_first;
+	    }
+	  if (match_first < left_lim)
+	    goto free_return;
+	  break;
+
+	default:
+	  /* In this case, we can't determine easily the current byte,
+	     since it might be a component byte of a multibyte
+	     character.  Then we use the constructed buffer instead.  */
+	  for (;;)
+	    {
+	      /* If MATCH_FIRST is out of the valid range, reconstruct the
+		 buffers.  */
+	      __re_size_t offset = match_first - mctx.input.raw_mbs_idx;
+	      if (BE (offset >= (__re_size_t) mctx.input.valid_raw_len, 0))
+		{
+		  err = re_string_reconstruct (&mctx.input, match_first,
+					       eflags);
+		  if (BE (err != REG_NOERROR, 0))
+		    goto free_return;
+
+		  offset = match_first - mctx.input.raw_mbs_idx;
+		}
+	      /* If MATCH_FIRST is out of the buffer, leave it as '\0'.
+		 Note that MATCH_FIRST must not be smaller than 0.  */
+	      ch = (match_first >= length
+		    ? 0 : re_string_byte_at (&mctx.input, offset));
+	      if (fastmap[ch])
+		break;
+	      match_first += incr;
+	      if (match_first < left_lim || match_first > right_lim)
+	        {
+	          err = REG_NOMATCH;
+	          goto free_return;
+	        }
+	    }
+	  break;
+	}
+
+      /* Reconstruct the buffers so that the matcher can assume that
+	 the matching starts from the beginning of the buffer.  */
+      err = re_string_reconstruct (&mctx.input, match_first, eflags);
+      if (BE (err != REG_NOERROR, 0))
+	goto free_return;
+
+#ifdef RE_ENABLE_I18N
+     /* Don't consider this char as a possible match start if it part,
+	yet isn't the head, of a multibyte character.  */
+      if (!sb && !re_string_first_byte (&mctx.input, 0))
+	continue;
+#endif
+
+      /* It seems to be appropriate one, then use the matcher.  */
+      /* We assume that the matching starts from 0.  */
+      mctx.state_log_top = mctx.nbkref_ents = mctx.max_mb_elem_len = 0;
+      match_last = check_matching (&mctx, fl_longest_match,
+				   start <= last_start ? &match_first : NULL);
+      if (match_last != REG_MISSING)
+	{
+	  if (BE (match_last == REG_ERROR, 0))
+	    {
+	      err = REG_ESPACE;
+	      goto free_return;
+	    }
+	  else
+	    {
+	      mctx.match_last = match_last;
+	      if ((!preg->no_sub && nmatch > 1) || dfa->nbackref)
+		{
+		  re_dfastate_t *pstate = mctx.state_log[match_last];
+		  mctx.last_node = check_halt_state_context (&mctx, pstate,
+							     match_last);
+		}
+	      if ((!preg->no_sub && nmatch > 1 && dfa->has_plural_match)
+		  || dfa->nbackref)
+		{
+		  err = prune_impossible_nodes (&mctx);
+		  if (err == REG_NOERROR)
+		    break;
+		  if (BE (err != REG_NOMATCH, 0))
+		    goto free_return;
+		  match_last = REG_MISSING;
+		}
+	      else
+		break; /* We found a match.  */
+	    }
+	}
+
+      match_ctx_clean (&mctx);
+    }
+
+#ifdef DEBUG
+  assert (match_last != REG_MISSING);
+  assert (err == REG_NOERROR);
+#endif
+
+  /* Set pmatch[] if we need.  */
+  if (nmatch > 0)
+    {
+      Idx reg_idx;
+
+      /* Initialize registers.  */
+      for (reg_idx = 1; reg_idx < nmatch; ++reg_idx)
+	pmatch[reg_idx].rm_so = pmatch[reg_idx].rm_eo = -1;
+
+      /* Set the points where matching start/end.  */
+      pmatch[0].rm_so = 0;
+      pmatch[0].rm_eo = mctx.match_last;
+      /* FIXME: This function should fail if mctx.match_last exceeds
+	 the maximum possible regoff_t value.  We need a new error
+	 code REG_OVERFLOW.  */
+
+      if (!preg->no_sub && nmatch > 1)
+	{
+	  err = set_regs (preg, &mctx, nmatch, pmatch,
+			  dfa->has_plural_match && dfa->nbackref > 0);
+	  if (BE (err != REG_NOERROR, 0))
+	    goto free_return;
+	}
+
+      /* At last, add the offset to the each registers, since we slided
+	 the buffers so that we could assume that the matching starts
+	 from 0.  */
+      for (reg_idx = 0; reg_idx < nmatch; ++reg_idx)
+	if (pmatch[reg_idx].rm_so != -1)
+	  {
+#ifdef RE_ENABLE_I18N
+	    if (BE (mctx.input.offsets_needed != 0, 0))
+	      {
+		pmatch[reg_idx].rm_so =
+		  (pmatch[reg_idx].rm_so == mctx.input.valid_len
+		   ? mctx.input.valid_raw_len
+		   : mctx.input.offsets[pmatch[reg_idx].rm_so]);
+		pmatch[reg_idx].rm_eo =
+		  (pmatch[reg_idx].rm_eo == mctx.input.valid_len
+		   ? mctx.input.valid_raw_len
+		   : mctx.input.offsets[pmatch[reg_idx].rm_eo]);
+	      }
+#else
+	    assert (mctx.input.offsets_needed == 0);
+#endif
+	    pmatch[reg_idx].rm_so += match_first;
+	    pmatch[reg_idx].rm_eo += match_first;
+	  }
+      for (reg_idx = 0; reg_idx < extra_nmatch; ++reg_idx)
+	{
+	  pmatch[nmatch + reg_idx].rm_so = -1;
+	  pmatch[nmatch + reg_idx].rm_eo = -1;
+	}
+
+      if (dfa->subexp_map)
+        for (reg_idx = 0; reg_idx + 1 < nmatch; reg_idx++)
+          if (dfa->subexp_map[reg_idx] != reg_idx)
+            {
+              pmatch[reg_idx + 1].rm_so
+                = pmatch[dfa->subexp_map[reg_idx] + 1].rm_so;
+              pmatch[reg_idx + 1].rm_eo
+                = pmatch[dfa->subexp_map[reg_idx] + 1].rm_eo;
+            }
+    }
+
+ free_return:
+  re_free (mctx.state_log);
+  if (dfa->nbackref)
+    match_ctx_free (&mctx);
+  re_string_destruct (&mctx.input);
+  return err;
+}
+
+static reg_errcode_t
+internal_function
+prune_impossible_nodes (re_match_context_t *mctx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx halt_node, match_last;
+  reg_errcode_t ret;
+  re_dfastate_t **sifted_states;
+  re_dfastate_t **lim_states = NULL;
+  re_sift_context_t sctx;
+#ifdef DEBUG
+  assert (mctx->state_log != NULL);
+#endif
+  match_last = mctx->match_last;
+  halt_node = mctx->last_node;
+
+  /* Avoid overflow.  */
+  if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= match_last, 0))
+    return REG_ESPACE;
+
+  sifted_states = re_malloc (re_dfastate_t *, match_last + 1);
+  if (BE (sifted_states == NULL, 0))
+    {
+      ret = REG_ESPACE;
+      goto free_return;
+    }
+  if (dfa->nbackref)
+    {
+      lim_states = re_malloc (re_dfastate_t *, match_last + 1);
+      if (BE (lim_states == NULL, 0))
+	{
+	  ret = REG_ESPACE;
+	  goto free_return;
+	}
+      while (1)
+	{
+	  memset (lim_states, '\0',
+		  sizeof (re_dfastate_t *) * (match_last + 1));
+	  sift_ctx_init (&sctx, sifted_states, lim_states, halt_node,
+			 match_last);
+	  ret = sift_states_backward (mctx, &sctx);
+	  re_node_set_free (&sctx.limits);
+	  if (BE (ret != REG_NOERROR, 0))
+	      goto free_return;
+	  if (sifted_states[0] != NULL || lim_states[0] != NULL)
+	    break;
+	  do
+	    {
+	      --match_last;
+	      if (! REG_VALID_INDEX (match_last))
+		{
+		  ret = REG_NOMATCH;
+		  goto free_return;
+		}
+	    } while (mctx->state_log[match_last] == NULL
+		     || !mctx->state_log[match_last]->halt);
+	  halt_node = check_halt_state_context (mctx,
+						mctx->state_log[match_last],
+						match_last);
+	}
+      ret = merge_state_array (dfa, sifted_states, lim_states,
+			       match_last + 1);
+      re_free (lim_states);
+      lim_states = NULL;
+      if (BE (ret != REG_NOERROR, 0))
+	goto free_return;
+    }
+  else
+    {
+      sift_ctx_init (&sctx, sifted_states, lim_states, halt_node, match_last);
+      ret = sift_states_backward (mctx, &sctx);
+      re_node_set_free (&sctx.limits);
+      if (BE (ret != REG_NOERROR, 0))
+	goto free_return;
+    }
+  re_free (mctx->state_log);
+  mctx->state_log = sifted_states;
+  sifted_states = NULL;
+  mctx->last_node = halt_node;
+  mctx->match_last = match_last;
+  ret = REG_NOERROR;
+ free_return:
+  re_free (sifted_states);
+  re_free (lim_states);
+  return ret;
+}
+
+/* Acquire an initial state and return it.
+   We must select appropriate initial state depending on the context,
+   since initial states may have constraints like "\<", "^", etc..  */
+
+static inline re_dfastate_t *
+__attribute ((always_inline)) internal_function
+acquire_init_state_context (reg_errcode_t *err, const re_match_context_t *mctx,
+			    Idx idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  if (dfa->init_state->has_constraint)
+    {
+      unsigned int context;
+      context = re_string_context_at (&mctx->input, idx - 1, mctx->eflags);
+      if (IS_WORD_CONTEXT (context))
+	return dfa->init_state_word;
+      else if (IS_ORDINARY_CONTEXT (context))
+	return dfa->init_state;
+      else if (IS_BEGBUF_CONTEXT (context) && IS_NEWLINE_CONTEXT (context))
+	return dfa->init_state_begbuf;
+      else if (IS_NEWLINE_CONTEXT (context))
+	return dfa->init_state_nl;
+      else if (IS_BEGBUF_CONTEXT (context))
+	{
+	  /* It is relatively rare case, then calculate on demand.  */
+	  return re_acquire_state_context (err, dfa,
+					   dfa->init_state->entrance_nodes,
+					   context);
+	}
+      else
+	/* Must not happen?  */
+	return dfa->init_state;
+    }
+  else
+    return dfa->init_state;
+}
+
+/* Check whether the regular expression match input string INPUT or not,
+   and return the index where the matching end.  Return REG_MISSING if
+   there is no match, and return REG_ERROR in case of an error.
+   FL_LONGEST_MATCH means we want the POSIX longest matching.
+   If P_MATCH_FIRST is not NULL, and the match fails, it is set to the
+   next place where we may want to try matching.
+   Note that the matcher assume that the maching starts from the current
+   index of the buffer.  */
+
+static Idx
+internal_function
+check_matching (re_match_context_t *mctx, bool fl_longest_match,
+		Idx *p_match_first)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx match = 0;
+  Idx match_last = REG_MISSING;
+  Idx cur_str_idx = re_string_cur_idx (&mctx->input);
+  re_dfastate_t *cur_state;
+  bool at_init_state = p_match_first != NULL;
+  Idx next_start_idx = cur_str_idx;
+
+  err = REG_NOERROR;
+  cur_state = acquire_init_state_context (&err, mctx, cur_str_idx);
+  /* An initial state must not be NULL (invalid).  */
+  if (BE (cur_state == NULL, 0))
+    {
+      assert (err == REG_ESPACE);
+      return REG_ERROR;
+    }
+
+  if (mctx->state_log != NULL)
+    {
+      mctx->state_log[cur_str_idx] = cur_state;
+
+      /* Check OP_OPEN_SUBEXP in the initial state in case that we use them
+	 later.  E.g. Processing back references.  */
+      if (BE (dfa->nbackref, 0))
+	{
+	  at_init_state = false;
+	  err = check_subexp_matching_top (mctx, &cur_state->nodes, 0);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+
+	  if (cur_state->has_backref)
+	    {
+	      err = transit_state_bkref (mctx, &cur_state->nodes);
+	      if (BE (err != REG_NOERROR, 0))
+	        return err;
+	    }
+	}
+    }
+
+  /* If the RE accepts NULL string.  */
+  if (BE (cur_state->halt, 0))
+    {
+      if (!cur_state->has_constraint
+	  || check_halt_state_context (mctx, cur_state, cur_str_idx))
+	{
+	  if (!fl_longest_match)
+	    return cur_str_idx;
+	  else
+	    {
+	      match_last = cur_str_idx;
+	      match = 1;
+	    }
+	}
+    }
+
+  while (!re_string_eoi (&mctx->input))
+    {
+      re_dfastate_t *old_state = cur_state;
+      Idx next_char_idx = re_string_cur_idx (&mctx->input) + 1;
+
+      if (BE (next_char_idx >= mctx->input.bufs_len, 0)
+          || (BE (next_char_idx >= mctx->input.valid_len, 0)
+              && mctx->input.valid_len < mctx->input.len))
+        {
+          err = extend_buffers (mctx);
+          if (BE (err != REG_NOERROR, 0))
+	    {
+	      assert (err == REG_ESPACE);
+	      return REG_ERROR;
+	    }
+        }
+
+      cur_state = transit_state (&err, mctx, cur_state);
+      if (mctx->state_log != NULL)
+	cur_state = merge_state_with_log (&err, mctx, cur_state);
+
+      if (cur_state == NULL)
+	{
+	  /* Reached the invalid state or an error.  Try to recover a valid
+	     state using the state log, if available and if we have not
+	     already found a valid (even if not the longest) match.  */
+	  if (BE (err != REG_NOERROR, 0))
+	    return REG_ERROR;
+
+	  if (mctx->state_log == NULL
+	      || (match && !fl_longest_match)
+	      || (cur_state = find_recover_state (&err, mctx)) == NULL)
+	    break;
+	}
+
+      if (BE (at_init_state, 0))
+	{
+	  if (old_state == cur_state)
+	    next_start_idx = next_char_idx;
+	  else
+	    at_init_state = false;
+	}
+
+      if (cur_state->halt)
+	{
+	  /* Reached a halt state.
+	     Check the halt state can satisfy the current context.  */
+	  if (!cur_state->has_constraint
+	      || check_halt_state_context (mctx, cur_state,
+					   re_string_cur_idx (&mctx->input)))
+	    {
+	      /* We found an appropriate halt state.  */
+	      match_last = re_string_cur_idx (&mctx->input);
+	      match = 1;
+
+	      /* We found a match, do not modify match_first below.  */
+	      p_match_first = NULL;
+	      if (!fl_longest_match)
+		break;
+	    }
+	}
+    }
+
+  if (p_match_first)
+    *p_match_first += next_start_idx;
+
+  return match_last;
+}
+
+/* Check NODE match the current context.  */
+
+static bool
+internal_function
+check_halt_node_context (const re_dfa_t *dfa, Idx node, unsigned int context)
+{
+  re_token_type_t type = dfa->nodes[node].type;
+  unsigned int constraint = dfa->nodes[node].constraint;
+  if (type != END_OF_RE)
+    return false;
+  if (!constraint)
+    return true;
+  if (NOT_SATISFY_NEXT_CONSTRAINT (constraint, context))
+    return false;
+  return true;
+}
+
+/* Check the halt state STATE match the current context.
+   Return 0 if not match, if the node, STATE has, is a halt node and
+   match the context, return the node.  */
+
+static Idx
+internal_function
+check_halt_state_context (const re_match_context_t *mctx,
+			  const re_dfastate_t *state, Idx idx)
+{
+  Idx i;
+  unsigned int context;
+#ifdef DEBUG
+  assert (state->halt);
+#endif
+  context = re_string_context_at (&mctx->input, idx, mctx->eflags);
+  for (i = 0; i < state->nodes.nelem; ++i)
+    if (check_halt_node_context (mctx->dfa, state->nodes.elems[i], context))
+      return state->nodes.elems[i];
+  return 0;
+}
+
+/* Compute the next node to which "NFA" transit from NODE("NFA" is a NFA
+   corresponding to the DFA).
+   Return the destination node, and update EPS_VIA_NODES;
+   return REG_MISSING in case of errors.  */
+
+static Idx
+internal_function
+proceed_next_node (const re_match_context_t *mctx, Idx nregs, regmatch_t *regs,
+		   Idx *pidx, Idx node, re_node_set *eps_via_nodes,
+		   struct re_fail_stack_t *fs)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx i;
+  bool ok;
+  if (IS_EPSILON_NODE (dfa->nodes[node].type))
+    {
+      re_node_set *cur_nodes = &mctx->state_log[*pidx]->nodes;
+      re_node_set *edests = &dfa->edests[node];
+      Idx dest_node;
+      ok = re_node_set_insert (eps_via_nodes, node);
+      if (BE (! ok, 0))
+	return REG_ERROR;
+      /* Pick up a valid destination, or return REG_MISSING if none
+	 is found.  */
+      for (dest_node = REG_MISSING, i = 0; i < edests->nelem; ++i)
+	{
+	  Idx candidate = edests->elems[i];
+	  if (!re_node_set_contains (cur_nodes, candidate))
+	    continue;
+          if (dest_node == REG_MISSING)
+	    dest_node = candidate;
+
+          else
+	    {
+	      /* In order to avoid infinite loop like "(a*)*", return the second
+	         epsilon-transition if the first was already considered.  */
+	      if (re_node_set_contains (eps_via_nodes, dest_node))
+	        return candidate;
+
+	      /* Otherwise, push the second epsilon-transition on the fail stack.  */
+	      else if (fs != NULL
+		       && push_fail_stack (fs, *pidx, candidate, nregs, regs,
+				           eps_via_nodes))
+		return REG_ERROR;
+
+	      /* We know we are going to exit.  */
+	      break;
+	    }
+	}
+      return dest_node;
+    }
+  else
+    {
+      Idx naccepted = 0;
+      re_token_type_t type = dfa->nodes[node].type;
+
+#ifdef RE_ENABLE_I18N
+      if (dfa->nodes[node].accept_mb)
+	naccepted = check_node_accept_bytes (dfa, node, &mctx->input, *pidx);
+      else
+#endif /* RE_ENABLE_I18N */
+      if (type == OP_BACK_REF)
+	{
+	  Idx subexp_idx = dfa->nodes[node].opr.idx + 1;
+	  naccepted = regs[subexp_idx].rm_eo - regs[subexp_idx].rm_so;
+	  if (fs != NULL)
+	    {
+	      if (regs[subexp_idx].rm_so == -1 || regs[subexp_idx].rm_eo == -1)
+		return REG_MISSING;
+	      else if (naccepted)
+		{
+		  char *buf = (char *) re_string_get_buffer (&mctx->input);
+		  if (memcmp (buf + regs[subexp_idx].rm_so, buf + *pidx,
+			      naccepted) != 0)
+		    return REG_MISSING;
+		}
+	    }
+
+	  if (naccepted == 0)
+	    {
+	      Idx dest_node;
+	      ok = re_node_set_insert (eps_via_nodes, node);
+	      if (BE (! ok, 0))
+		return REG_ERROR;
+	      dest_node = dfa->edests[node].elems[0];
+	      if (re_node_set_contains (&mctx->state_log[*pidx]->nodes,
+					dest_node))
+		return dest_node;
+	    }
+	}
+
+      if (naccepted != 0
+	  || check_node_accept (mctx, dfa->nodes + node, *pidx))
+	{
+	  Idx dest_node = dfa->nexts[node];
+	  *pidx = (naccepted == 0) ? *pidx + 1 : *pidx + naccepted;
+	  if (fs && (*pidx > mctx->match_last || mctx->state_log[*pidx] == NULL
+		     || !re_node_set_contains (&mctx->state_log[*pidx]->nodes,
+					       dest_node)))
+	    return REG_MISSING;
+	  re_node_set_empty (eps_via_nodes);
+	  return dest_node;
+	}
+    }
+  return REG_MISSING;
+}
+
+static reg_errcode_t
+internal_function
+push_fail_stack (struct re_fail_stack_t *fs, Idx str_idx, Idx dest_node,
+		 Idx nregs, regmatch_t *regs, re_node_set *eps_via_nodes)
+{
+  reg_errcode_t err;
+  Idx num = fs->num++;
+  if (fs->num == fs->alloc)
+    {
+      struct re_fail_stack_ent_t *new_array;
+      new_array = realloc (fs->stack, (sizeof (struct re_fail_stack_ent_t)
+				       * fs->alloc * 2));
+      if (new_array == NULL)
+	return REG_ESPACE;
+      fs->alloc *= 2;
+      fs->stack = new_array;
+    }
+  fs->stack[num].idx = str_idx;
+  fs->stack[num].node = dest_node;
+  fs->stack[num].regs = re_malloc (regmatch_t, nregs);
+  if (fs->stack[num].regs == NULL)
+    return REG_ESPACE;
+  memcpy (fs->stack[num].regs, regs, sizeof (regmatch_t) * nregs);
+  err = re_node_set_init_copy (&fs->stack[num].eps_via_nodes, eps_via_nodes);
+  return err;
+}
+
+static Idx
+internal_function
+pop_fail_stack (struct re_fail_stack_t *fs, Idx *pidx, Idx nregs,
+		regmatch_t *regs, re_node_set *eps_via_nodes)
+{
+  Idx num = --fs->num;
+  assert (REG_VALID_INDEX (num));
+  *pidx = fs->stack[num].idx;
+  memcpy (regs, fs->stack[num].regs, sizeof (regmatch_t) * nregs);
+  re_node_set_free (eps_via_nodes);
+  re_free (fs->stack[num].regs);
+  *eps_via_nodes = fs->stack[num].eps_via_nodes;
+  return fs->stack[num].node;
+}
+
+/* Set the positions where the subexpressions are starts/ends to registers
+   PMATCH.
+   Note: We assume that pmatch[0] is already set, and
+   pmatch[i].rm_so == pmatch[i].rm_eo == -1 for 0 < i < nmatch.  */
+
+static reg_errcode_t
+internal_function
+set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
+	  regmatch_t *pmatch, bool fl_backtrack)
+{
+  const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer;
+  Idx idx, cur_node;
+  re_node_set eps_via_nodes;
+  struct re_fail_stack_t *fs;
+  struct re_fail_stack_t fs_body = { 0, 2, NULL };
+  regmatch_t *prev_idx_match;
+  bool prev_idx_match_malloced = false;
+
+#ifdef DEBUG
+  assert (nmatch > 1);
+  assert (mctx->state_log != NULL);
+#endif
+  if (fl_backtrack)
+    {
+      fs = &fs_body;
+      fs->stack = re_malloc (struct re_fail_stack_ent_t, fs->alloc);
+      if (fs->stack == NULL)
+	return REG_ESPACE;
+    }
+  else
+    fs = NULL;
+
+  cur_node = dfa->init_node;
+  re_node_set_init_empty (&eps_via_nodes);
+
+  if (__libc_use_alloca (nmatch * sizeof (regmatch_t)))
+    prev_idx_match = (regmatch_t *) alloca (nmatch * sizeof (regmatch_t));
+  else
+    {
+      prev_idx_match = re_malloc (regmatch_t, nmatch);
+      if (prev_idx_match == NULL)
+	{
+	  free_fail_stack_return (fs);
+	  return REG_ESPACE;
+	}
+      prev_idx_match_malloced = true;
+    }
+  memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+
+  for (idx = pmatch[0].rm_so; idx <= pmatch[0].rm_eo ;)
+    {
+      update_regs (dfa, pmatch, prev_idx_match, cur_node, idx, nmatch);
+
+      if (idx == pmatch[0].rm_eo && cur_node == mctx->last_node)
+	{
+	  Idx reg_idx;
+	  if (fs)
+	    {
+	      for (reg_idx = 0; reg_idx < nmatch; ++reg_idx)
+		if (pmatch[reg_idx].rm_so > -1 && pmatch[reg_idx].rm_eo == -1)
+		  break;
+	      if (reg_idx == nmatch)
+		{
+		  re_node_set_free (&eps_via_nodes);
+		  if (prev_idx_match_malloced)
+		    re_free (prev_idx_match);
+		  return free_fail_stack_return (fs);
+		}
+	      cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch,
+					 &eps_via_nodes);
+	    }
+	  else
+	    {
+	      re_node_set_free (&eps_via_nodes);
+	      if (prev_idx_match_malloced)
+		re_free (prev_idx_match);
+	      return REG_NOERROR;
+	    }
+	}
+
+      /* Proceed to next node.  */
+      cur_node = proceed_next_node (mctx, nmatch, pmatch, &idx, cur_node,
+				    &eps_via_nodes, fs);
+
+      if (BE (! REG_VALID_INDEX (cur_node), 0))
+	{
+	  if (BE (cur_node == REG_ERROR, 0))
+	    {
+	      re_node_set_free (&eps_via_nodes);
+	      if (prev_idx_match_malloced)
+		re_free (prev_idx_match);
+	      free_fail_stack_return (fs);
+	      return REG_ESPACE;
+	    }
+	  if (fs)
+	    cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch,
+				       &eps_via_nodes);
+	  else
+	    {
+	      re_node_set_free (&eps_via_nodes);
+	      if (prev_idx_match_malloced)
+		re_free (prev_idx_match);
+	      return REG_NOMATCH;
+	    }
+	}
+    }
+  re_node_set_free (&eps_via_nodes);
+  if (prev_idx_match_malloced)
+    re_free (prev_idx_match);
+  return free_fail_stack_return (fs);
+}
+
+static reg_errcode_t
+internal_function
+free_fail_stack_return (struct re_fail_stack_t *fs)
+{
+  if (fs)
+    {
+      Idx fs_idx;
+      for (fs_idx = 0; fs_idx < fs->num; ++fs_idx)
+	{
+	  re_node_set_free (&fs->stack[fs_idx].eps_via_nodes);
+	  re_free (fs->stack[fs_idx].regs);
+	}
+      re_free (fs->stack);
+    }
+  return REG_NOERROR;
+}
+
+static void
+internal_function
+update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
+	     regmatch_t *prev_idx_match, Idx cur_node, Idx cur_idx, Idx nmatch)
+{
+  int type = dfa->nodes[cur_node].type;
+  if (type == OP_OPEN_SUBEXP)
+    {
+      Idx reg_num = dfa->nodes[cur_node].opr.idx + 1;
+
+      /* We are at the first node of this sub expression.  */
+      if (reg_num < nmatch)
+	{
+	  pmatch[reg_num].rm_so = cur_idx;
+	  pmatch[reg_num].rm_eo = -1;
+	}
+    }
+  else if (type == OP_CLOSE_SUBEXP)
+    {
+      Idx reg_num = dfa->nodes[cur_node].opr.idx + 1;
+      if (reg_num < nmatch)
+	{
+	  /* We are at the last node of this sub expression.  */
+	  if (pmatch[reg_num].rm_so < cur_idx)
+	    {
+	      pmatch[reg_num].rm_eo = cur_idx;
+	      /* This is a non-empty match or we are not inside an optional
+		 subexpression.  Accept this right away.  */
+	      memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+	    }
+	  else
+	    {
+	      if (dfa->nodes[cur_node].opt_subexp
+		  && prev_idx_match[reg_num].rm_so != -1)
+		/* We transited through an empty match for an optional
+		   subexpression, like (a?)*, and this is not the subexp's
+		   first match.  Copy back the old content of the registers
+		   so that matches of an inner subexpression are undone as
+		   well, like in ((a?))*.  */
+		memcpy (pmatch, prev_idx_match, sizeof (regmatch_t) * nmatch);
+	      else
+		/* We completed a subexpression, but it may be part of
+		   an optional one, so do not update PREV_IDX_MATCH.  */
+		pmatch[reg_num].rm_eo = cur_idx;
+	    }
+	}
+    }
+}
+
+/* This function checks the STATE_LOG from the SCTX->last_str_idx to 0
+   and sift the nodes in each states according to the following rules.
+   Updated state_log will be wrote to STATE_LOG.
+
+   Rules: We throw away the Node `a' in the STATE_LOG[STR_IDX] if...
+     1. When STR_IDX == MATCH_LAST(the last index in the state_log):
+	If `a' isn't the LAST_NODE and `a' can't epsilon transit to
+	the LAST_NODE, we throw away the node `a'.
+     2. When 0 <= STR_IDX < MATCH_LAST and `a' accepts
+	string `s' and transit to `b':
+	i. If 'b' isn't in the STATE_LOG[STR_IDX+strlen('s')], we throw
+	   away the node `a'.
+	ii. If 'b' is in the STATE_LOG[STR_IDX+strlen('s')] but 'b' is
+	    thrown away, we throw away the node `a'.
+     3. When 0 <= STR_IDX < MATCH_LAST and 'a' epsilon transit to 'b':
+	i. If 'b' isn't in the STATE_LOG[STR_IDX], we throw away the
+	   node `a'.
+	ii. If 'b' is in the STATE_LOG[STR_IDX] but 'b' is thrown away,
+	    we throw away the node `a'.  */
+
+#define STATE_NODE_CONTAINS(state,node) \
+  ((state) != NULL && re_node_set_contains (&(state)->nodes, node))
+
+static reg_errcode_t
+internal_function
+sift_states_backward (const re_match_context_t *mctx, re_sift_context_t *sctx)
+{
+  reg_errcode_t err;
+  int null_cnt = 0;
+  Idx str_idx = sctx->last_str_idx;
+  re_node_set cur_dest;
+
+#ifdef DEBUG
+  assert (mctx->state_log != NULL && mctx->state_log[str_idx] != NULL);
+#endif
+
+  /* Build sifted state_log[str_idx].  It has the nodes which can epsilon
+     transit to the last_node and the last_node itself.  */
+  err = re_node_set_init_1 (&cur_dest, sctx->last_node);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+
+  /* Then check each states in the state_log.  */
+  while (str_idx > 0)
+    {
+      /* Update counters.  */
+      null_cnt = (sctx->sifted_states[str_idx] == NULL) ? null_cnt + 1 : 0;
+      if (null_cnt > mctx->max_mb_elem_len)
+	{
+	  memset (sctx->sifted_states, '\0',
+		  sizeof (re_dfastate_t *) * str_idx);
+	  re_node_set_free (&cur_dest);
+	  return REG_NOERROR;
+	}
+      re_node_set_empty (&cur_dest);
+      --str_idx;
+
+      if (mctx->state_log[str_idx])
+	{
+	  err = build_sifted_states (mctx, sctx, str_idx, &cur_dest);
+          if (BE (err != REG_NOERROR, 0))
+	    goto free_return;
+	}
+
+      /* Add all the nodes which satisfy the following conditions:
+	 - It can epsilon transit to a node in CUR_DEST.
+	 - It is in CUR_SRC.
+	 And update state_log.  */
+      err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest);
+      if (BE (err != REG_NOERROR, 0))
+	goto free_return;
+    }
+  err = REG_NOERROR;
+ free_return:
+  re_node_set_free (&cur_dest);
+  return err;
+}
+
+static reg_errcode_t
+internal_function
+build_sifted_states (const re_match_context_t *mctx, re_sift_context_t *sctx,
+		     Idx str_idx, re_node_set *cur_dest)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  const re_node_set *cur_src = &mctx->state_log[str_idx]->non_eps_nodes;
+  Idx i;
+
+  /* Then build the next sifted state.
+     We build the next sifted state on `cur_dest', and update
+     `sifted_states[str_idx]' with `cur_dest'.
+     Note:
+     `cur_dest' is the sifted state from `state_log[str_idx + 1]'.
+     `cur_src' points the node_set of the old `state_log[str_idx]'
+     (with the epsilon nodes pre-filtered out).  */
+  for (i = 0; i < cur_src->nelem; i++)
+    {
+      Idx prev_node = cur_src->elems[i];
+      int naccepted = 0;
+      bool ok;
+
+#ifdef DEBUG
+      re_token_type_t type = dfa->nodes[prev_node].type;
+      assert (!IS_EPSILON_NODE (type));
+#endif
+#ifdef RE_ENABLE_I18N
+      /* If the node may accept `multi byte'.  */
+      if (dfa->nodes[prev_node].accept_mb)
+	naccepted = sift_states_iter_mb (mctx, sctx, prev_node,
+					 str_idx, sctx->last_str_idx);
+#endif /* RE_ENABLE_I18N */
+
+      /* We don't check backreferences here.
+	 See update_cur_sifted_state().  */
+      if (!naccepted
+	  && check_node_accept (mctx, dfa->nodes + prev_node, str_idx)
+	  && STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + 1],
+				  dfa->nexts[prev_node]))
+	naccepted = 1;
+
+      if (naccepted == 0)
+	continue;
+
+      if (sctx->limits.nelem)
+	{
+	  Idx to_idx = str_idx + naccepted;
+	  if (check_dst_limits (mctx, &sctx->limits,
+				dfa->nexts[prev_node], to_idx,
+				prev_node, str_idx))
+	    continue;
+	}
+      ok = re_node_set_insert (cur_dest, prev_node);
+      if (BE (! ok, 0))
+	return REG_ESPACE;
+    }
+
+  return REG_NOERROR;
+}
+
+/* Helper functions.  */
+
+static reg_errcode_t
+internal_function
+clean_state_log_if_needed (re_match_context_t *mctx, Idx next_state_log_idx)
+{
+  Idx top = mctx->state_log_top;
+
+  if (next_state_log_idx >= mctx->input.bufs_len
+      || (next_state_log_idx >= mctx->input.valid_len
+	  && mctx->input.valid_len < mctx->input.len))
+    {
+      reg_errcode_t err;
+      err = extend_buffers (mctx);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+
+  if (top < next_state_log_idx)
+    {
+      memset (mctx->state_log + top + 1, '\0',
+	      sizeof (re_dfastate_t *) * (next_state_log_idx - top));
+      mctx->state_log_top = next_state_log_idx;
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+merge_state_array (const re_dfa_t *dfa, re_dfastate_t **dst,
+		   re_dfastate_t **src, Idx num)
+{
+  Idx st_idx;
+  reg_errcode_t err;
+  for (st_idx = 0; st_idx < num; ++st_idx)
+    {
+      if (dst[st_idx] == NULL)
+	dst[st_idx] = src[st_idx];
+      else if (src[st_idx] != NULL)
+	{
+	  re_node_set merged_set;
+	  err = re_node_set_init_union (&merged_set, &dst[st_idx]->nodes,
+					&src[st_idx]->nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	  dst[st_idx] = re_acquire_state (&err, dfa, &merged_set);
+	  re_node_set_free (&merged_set);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+update_cur_sifted_state (const re_match_context_t *mctx,
+			 re_sift_context_t *sctx, Idx str_idx,
+			 re_node_set *dest_nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err = REG_NOERROR;
+  const re_node_set *candidates;
+  candidates = ((mctx->state_log[str_idx] == NULL) ? NULL
+		: &mctx->state_log[str_idx]->nodes);
+
+  if (dest_nodes->nelem == 0)
+    sctx->sifted_states[str_idx] = NULL;
+  else
+    {
+      if (candidates)
+	{
+	  /* At first, add the nodes which can epsilon transit to a node in
+	     DEST_NODE.  */
+	  err = add_epsilon_src_nodes (dfa, dest_nodes, candidates);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+
+	  /* Then, check the limitations in the current sift_context.  */
+	  if (sctx->limits.nelem)
+	    {
+	      err = check_subexp_limits (dfa, dest_nodes, candidates, &sctx->limits,
+					 mctx->bkref_ents, str_idx);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+	}
+
+      sctx->sifted_states[str_idx] = re_acquire_state (&err, dfa, dest_nodes);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+
+  if (candidates && mctx->state_log[str_idx]->has_backref)
+    {
+      err = sift_states_bkref (mctx, sctx, str_idx, candidates);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+add_epsilon_src_nodes (const re_dfa_t *dfa, re_node_set *dest_nodes,
+		       const re_node_set *candidates)
+{
+  reg_errcode_t err = REG_NOERROR;
+  Idx i;
+
+  re_dfastate_t *state = re_acquire_state (&err, dfa, dest_nodes);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  if (!state->inveclosure.alloc)
+    {
+      err = re_node_set_alloc (&state->inveclosure, dest_nodes->nelem);
+      if (BE (err != REG_NOERROR, 0))
+        return REG_ESPACE;
+      for (i = 0; i < dest_nodes->nelem; i++)
+        re_node_set_merge (&state->inveclosure,
+			   dfa->inveclosures + dest_nodes->elems[i]);
+    }
+  return re_node_set_add_intersect (dest_nodes, candidates,
+				    &state->inveclosure);
+}
+
+static reg_errcode_t
+internal_function
+sub_epsilon_src_nodes (const re_dfa_t *dfa, Idx node, re_node_set *dest_nodes,
+		       const re_node_set *candidates)
+{
+    Idx ecl_idx;
+    reg_errcode_t err;
+    re_node_set *inv_eclosure = dfa->inveclosures + node;
+    re_node_set except_nodes;
+    re_node_set_init_empty (&except_nodes);
+    for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx)
+      {
+	Idx cur_node = inv_eclosure->elems[ecl_idx];
+	if (cur_node == node)
+	  continue;
+	if (IS_EPSILON_NODE (dfa->nodes[cur_node].type))
+	  {
+	    Idx edst1 = dfa->edests[cur_node].elems[0];
+	    Idx edst2 = ((dfa->edests[cur_node].nelem > 1)
+			 ? dfa->edests[cur_node].elems[1] : REG_MISSING);
+	    if ((!re_node_set_contains (inv_eclosure, edst1)
+		 && re_node_set_contains (dest_nodes, edst1))
+		|| (REG_VALID_NONZERO_INDEX (edst2)
+		    && !re_node_set_contains (inv_eclosure, edst2)
+		    && re_node_set_contains (dest_nodes, edst2)))
+	      {
+		err = re_node_set_add_intersect (&except_nodes, candidates,
+						 dfa->inveclosures + cur_node);
+		if (BE (err != REG_NOERROR, 0))
+		  {
+		    re_node_set_free (&except_nodes);
+		    return err;
+		  }
+	      }
+	  }
+      }
+    for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx)
+      {
+	Idx cur_node = inv_eclosure->elems[ecl_idx];
+	if (!re_node_set_contains (&except_nodes, cur_node))
+	  {
+	    Idx idx = re_node_set_contains (dest_nodes, cur_node) - 1;
+	    re_node_set_remove_at (dest_nodes, idx);
+	  }
+      }
+    re_node_set_free (&except_nodes);
+    return REG_NOERROR;
+}
+
+static bool
+internal_function
+check_dst_limits (const re_match_context_t *mctx, const re_node_set *limits,
+		  Idx dst_node, Idx dst_idx, Idx src_node, Idx src_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx lim_idx, src_pos, dst_pos;
+
+  Idx dst_bkref_idx = search_cur_bkref_entry (mctx, dst_idx);
+  Idx src_bkref_idx = search_cur_bkref_entry (mctx, src_idx);
+  for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx)
+    {
+      Idx subexp_idx;
+      struct re_backref_cache_entry *ent;
+      ent = mctx->bkref_ents + limits->elems[lim_idx];
+      subexp_idx = dfa->nodes[ent->node].opr.idx;
+
+      dst_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx],
+					   subexp_idx, dst_node, dst_idx,
+					   dst_bkref_idx);
+      src_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx],
+					   subexp_idx, src_node, src_idx,
+					   src_bkref_idx);
+
+      /* In case of:
+	 <src> <dst> ( <subexp> )
+	 ( <subexp> ) <src> <dst>
+	 ( <subexp1> <src> <subexp2> <dst> <subexp3> )  */
+      if (src_pos == dst_pos)
+	continue; /* This is unrelated limitation.  */
+      else
+	return true;
+    }
+  return false;
+}
+
+static int
+internal_function
+check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, int boundaries,
+			     Idx subexp_idx, Idx from_node, Idx bkref_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  const re_node_set *eclosures = dfa->eclosures + from_node;
+  Idx node_idx;
+
+  /* Else, we are on the boundary: examine the nodes on the epsilon
+     closure.  */
+  for (node_idx = 0; node_idx < eclosures->nelem; ++node_idx)
+    {
+      Idx node = eclosures->elems[node_idx];
+      switch (dfa->nodes[node].type)
+	{
+	case OP_BACK_REF:
+	  if (bkref_idx != REG_MISSING)
+	    {
+	      struct re_backref_cache_entry *ent = mctx->bkref_ents + bkref_idx;
+	      do
+	        {
+		  Idx dst;
+		  int cpos;
+
+		  if (ent->node != node)
+		    continue;
+
+		  if (subexp_idx < BITSET_WORD_BITS
+		      && !(ent->eps_reachable_subexps_map
+			   & ((bitset_word_t) 1 << subexp_idx)))
+		    continue;
+
+		  /* Recurse trying to reach the OP_OPEN_SUBEXP and
+		     OP_CLOSE_SUBEXP cases below.  But, if the
+		     destination node is the same node as the source
+		     node, don't recurse because it would cause an
+		     infinite loop: a regex that exhibits this behavior
+		     is ()\1*\1*  */
+		  dst = dfa->edests[node].elems[0];
+		  if (dst == from_node)
+		    {
+		      if (boundaries & 1)
+		        return -1;
+		      else /* if (boundaries & 2) */
+		        return 0;
+		    }
+
+		  cpos =
+		    check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx,
+						 dst, bkref_idx);
+		  if (cpos == -1 /* && (boundaries & 1) */)
+		    return -1;
+		  if (cpos == 0 && (boundaries & 2))
+		    return 0;
+
+		  if (subexp_idx < BITSET_WORD_BITS)
+		    ent->eps_reachable_subexps_map
+		      &= ~((bitset_word_t) 1 << subexp_idx);
+	        }
+	      while (ent++->more);
+	    }
+	  break;
+
+	case OP_OPEN_SUBEXP:
+	  if ((boundaries & 1) && subexp_idx == dfa->nodes[node].opr.idx)
+	    return -1;
+	  break;
+
+	case OP_CLOSE_SUBEXP:
+	  if ((boundaries & 2) && subexp_idx == dfa->nodes[node].opr.idx)
+	    return 0;
+	  break;
+
+	default:
+	    break;
+	}
+    }
+
+  return (boundaries & 2) ? 1 : 0;
+}
+
+static int
+internal_function
+check_dst_limits_calc_pos (const re_match_context_t *mctx, Idx limit,
+			   Idx subexp_idx, Idx from_node, Idx str_idx,
+			   Idx bkref_idx)
+{
+  struct re_backref_cache_entry *lim = mctx->bkref_ents + limit;
+  int boundaries;
+
+  /* If we are outside the range of the subexpression, return -1 or 1.  */
+  if (str_idx < lim->subexp_from)
+    return -1;
+
+  if (lim->subexp_to < str_idx)
+    return 1;
+
+  /* If we are within the subexpression, return 0.  */
+  boundaries = (str_idx == lim->subexp_from);
+  boundaries |= (str_idx == lim->subexp_to) << 1;
+  if (boundaries == 0)
+    return 0;
+
+  /* Else, examine epsilon closure.  */
+  return check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx,
+				      from_node, bkref_idx);
+}
+
+/* Check the limitations of sub expressions LIMITS, and remove the nodes
+   which are against limitations from DEST_NODES. */
+
+static reg_errcode_t
+internal_function
+check_subexp_limits (const re_dfa_t *dfa, re_node_set *dest_nodes,
+		     const re_node_set *candidates, re_node_set *limits,
+		     struct re_backref_cache_entry *bkref_ents, Idx str_idx)
+{
+  reg_errcode_t err;
+  Idx node_idx, lim_idx;
+
+  for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx)
+    {
+      Idx subexp_idx;
+      struct re_backref_cache_entry *ent;
+      ent = bkref_ents + limits->elems[lim_idx];
+
+      if (str_idx <= ent->subexp_from || ent->str_idx < str_idx)
+	continue; /* This is unrelated limitation.  */
+
+      subexp_idx = dfa->nodes[ent->node].opr.idx;
+      if (ent->subexp_to == str_idx)
+	{
+	  Idx ops_node = REG_MISSING;
+	  Idx cls_node = REG_MISSING;
+	  for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+	    {
+	      Idx node = dest_nodes->elems[node_idx];
+	      re_token_type_t type = dfa->nodes[node].type;
+	      if (type == OP_OPEN_SUBEXP
+		  && subexp_idx == dfa->nodes[node].opr.idx)
+		ops_node = node;
+	      else if (type == OP_CLOSE_SUBEXP
+		       && subexp_idx == dfa->nodes[node].opr.idx)
+		cls_node = node;
+	    }
+
+	  /* Check the limitation of the open subexpression.  */
+	  /* Note that (ent->subexp_to = str_idx != ent->subexp_from).  */
+	  if (REG_VALID_INDEX (ops_node))
+	    {
+	      err = sub_epsilon_src_nodes (dfa, ops_node, dest_nodes,
+					   candidates);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+
+	  /* Check the limitation of the close subexpression.  */
+	  if (REG_VALID_INDEX (cls_node))
+	    for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+	      {
+		Idx node = dest_nodes->elems[node_idx];
+		if (!re_node_set_contains (dfa->inveclosures + node,
+					   cls_node)
+		    && !re_node_set_contains (dfa->eclosures + node,
+					      cls_node))
+		  {
+		    /* It is against this limitation.
+		       Remove it form the current sifted state.  */
+		    err = sub_epsilon_src_nodes (dfa, node, dest_nodes,
+						 candidates);
+		    if (BE (err != REG_NOERROR, 0))
+		      return err;
+		    --node_idx;
+		  }
+	      }
+	}
+      else /* (ent->subexp_to != str_idx)  */
+	{
+	  for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+	    {
+	      Idx node = dest_nodes->elems[node_idx];
+	      re_token_type_t type = dfa->nodes[node].type;
+	      if (type == OP_CLOSE_SUBEXP || type == OP_OPEN_SUBEXP)
+		{
+		  if (subexp_idx != dfa->nodes[node].opr.idx)
+		    continue;
+		  /* It is against this limitation.
+		     Remove it form the current sifted state.  */
+		  err = sub_epsilon_src_nodes (dfa, node, dest_nodes,
+					       candidates);
+		  if (BE (err != REG_NOERROR, 0))
+		    return err;
+		}
+	    }
+	}
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+sift_states_bkref (const re_match_context_t *mctx, re_sift_context_t *sctx,
+		   Idx str_idx, const re_node_set *candidates)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx node_idx, node;
+  re_sift_context_t local_sctx;
+  Idx first_idx = search_cur_bkref_entry (mctx, str_idx);
+
+  if (first_idx == REG_MISSING)
+    return REG_NOERROR;
+
+  local_sctx.sifted_states = NULL; /* Mark that it hasn't been initialized.  */
+
+  for (node_idx = 0; node_idx < candidates->nelem; ++node_idx)
+    {
+      Idx enabled_idx;
+      re_token_type_t type;
+      struct re_backref_cache_entry *entry;
+      node = candidates->elems[node_idx];
+      type = dfa->nodes[node].type;
+      /* Avoid infinite loop for the REs like "()\1+".  */
+      if (node == sctx->last_node && str_idx == sctx->last_str_idx)
+	continue;
+      if (type != OP_BACK_REF)
+	continue;
+
+      entry = mctx->bkref_ents + first_idx;
+      enabled_idx = first_idx;
+      do
+	{
+	  Idx subexp_len;
+	  Idx to_idx;
+	  Idx dst_node;
+	  bool ok;
+	  re_dfastate_t *cur_state;
+
+	  if (entry->node != node)
+	    continue;
+	  subexp_len = entry->subexp_to - entry->subexp_from;
+	  to_idx = str_idx + subexp_len;
+	  dst_node = (subexp_len ? dfa->nexts[node]
+		      : dfa->edests[node].elems[0]);
+
+	  if (to_idx > sctx->last_str_idx
+	      || sctx->sifted_states[to_idx] == NULL
+	      || !STATE_NODE_CONTAINS (sctx->sifted_states[to_idx], dst_node)
+	      || check_dst_limits (mctx, &sctx->limits, node,
+				   str_idx, dst_node, to_idx))
+	    continue;
+
+	  if (local_sctx.sifted_states == NULL)
+	    {
+	      local_sctx = *sctx;
+	      err = re_node_set_init_copy (&local_sctx.limits, &sctx->limits);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  local_sctx.last_node = node;
+	  local_sctx.last_str_idx = str_idx;
+	  ok = re_node_set_insert (&local_sctx.limits, enabled_idx);
+	  if (BE (! ok, 0))
+	    {
+	      err = REG_ESPACE;
+	      goto free_return;
+	    }
+	  cur_state = local_sctx.sifted_states[str_idx];
+	  err = sift_states_backward (mctx, &local_sctx);
+	  if (BE (err != REG_NOERROR, 0))
+	    goto free_return;
+	  if (sctx->limited_states != NULL)
+	    {
+	      err = merge_state_array (dfa, sctx->limited_states,
+				       local_sctx.sifted_states,
+				       str_idx + 1);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  local_sctx.sifted_states[str_idx] = cur_state;
+	  re_node_set_remove (&local_sctx.limits, enabled_idx);
+
+	  /* mctx->bkref_ents may have changed, reload the pointer.  */
+          entry = mctx->bkref_ents + enabled_idx;
+	}
+      while (enabled_idx++, entry++->more);
+    }
+  err = REG_NOERROR;
+ free_return:
+  if (local_sctx.sifted_states != NULL)
+    {
+      re_node_set_free (&local_sctx.limits);
+    }
+
+  return err;
+}
+
+
+#ifdef RE_ENABLE_I18N
+static int
+internal_function
+sift_states_iter_mb (const re_match_context_t *mctx, re_sift_context_t *sctx,
+		     Idx node_idx, Idx str_idx, Idx max_str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int naccepted;
+  /* Check the node can accept `multi byte'.  */
+  naccepted = check_node_accept_bytes (dfa, node_idx, &mctx->input, str_idx);
+  if (naccepted > 0 && str_idx + naccepted <= max_str_idx &&
+      !STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + naccepted],
+			    dfa->nexts[node_idx]))
+    /* The node can't accept the `multi byte', or the
+       destination was already thrown away, then the node
+       could't accept the current input `multi byte'.   */
+    naccepted = 0;
+  /* Otherwise, it is sure that the node could accept
+     `naccepted' bytes input.  */
+  return naccepted;
+}
+#endif /* RE_ENABLE_I18N */
+
+
+/* Functions for state transition.  */
+
+/* Return the next state to which the current state STATE will transit by
+   accepting the current input byte, and update STATE_LOG if necessary.
+   If STATE can accept a multibyte char/collating element/back reference
+   update the destination of STATE_LOG.  */
+
+static re_dfastate_t *
+internal_function
+transit_state (reg_errcode_t *err, re_match_context_t *mctx,
+	       re_dfastate_t *state)
+{
+  re_dfastate_t **trtable;
+  unsigned char ch;
+
+#ifdef RE_ENABLE_I18N
+  /* If the current state can accept multibyte.  */
+  if (BE (state->accept_mb, 0))
+    {
+      *err = transit_state_mb (mctx, state);
+      if (BE (*err != REG_NOERROR, 0))
+	return NULL;
+    }
+#endif /* RE_ENABLE_I18N */
+
+  /* Then decide the next state with the single byte.  */
+#if 0
+  if (0)
+    /* don't use transition table  */
+    return transit_state_sb (err, mctx, state);
+#endif
+
+  /* Use transition table  */
+  ch = re_string_fetch_byte (&mctx->input);
+  for (;;)
+    {
+      trtable = state->trtable;
+      if (BE (trtable != NULL, 1))
+	return trtable[ch];
+
+      trtable = state->word_trtable;
+      if (BE (trtable != NULL, 1))
+        {
+	  unsigned int context;
+	  context
+	    = re_string_context_at (&mctx->input,
+				    re_string_cur_idx (&mctx->input) - 1,
+				    mctx->eflags);
+	  if (IS_WORD_CONTEXT (context))
+	    return trtable[ch + SBC_MAX];
+	  else
+	    return trtable[ch];
+	}
+
+      if (!build_trtable (mctx->dfa, state))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+
+      /* Retry, we now have a transition table.  */
+    }
+}
+
+/* Update the state_log if we need */
+re_dfastate_t *
+internal_function
+merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx,
+		      re_dfastate_t *next_state)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx cur_idx = re_string_cur_idx (&mctx->input);
+
+  if (cur_idx > mctx->state_log_top)
+    {
+      mctx->state_log[cur_idx] = next_state;
+      mctx->state_log_top = cur_idx;
+    }
+  else if (mctx->state_log[cur_idx] == 0)
+    {
+      mctx->state_log[cur_idx] = next_state;
+    }
+  else
+    {
+      re_dfastate_t *pstate;
+      unsigned int context;
+      re_node_set next_nodes, *log_nodes, *table_nodes = NULL;
+      /* If (state_log[cur_idx] != 0), it implies that cur_idx is
+         the destination of a multibyte char/collating element/
+         back reference.  Then the next state is the union set of
+         these destinations and the results of the transition table.  */
+      pstate = mctx->state_log[cur_idx];
+      log_nodes = pstate->entrance_nodes;
+      if (next_state != NULL)
+        {
+          table_nodes = next_state->entrance_nodes;
+          *err = re_node_set_init_union (&next_nodes, table_nodes,
+					     log_nodes);
+          if (BE (*err != REG_NOERROR, 0))
+	    return NULL;
+        }
+      else
+        next_nodes = *log_nodes;
+      /* Note: We already add the nodes of the initial state,
+	 then we don't need to add them here.  */
+
+      context = re_string_context_at (&mctx->input,
+				      re_string_cur_idx (&mctx->input) - 1,
+				      mctx->eflags);
+      next_state = mctx->state_log[cur_idx]
+        = re_acquire_state_context (err, dfa, &next_nodes, context);
+      /* We don't need to check errors here, since the return value of
+         this function is next_state and ERR is already set.  */
+
+      if (table_nodes != NULL)
+        re_node_set_free (&next_nodes);
+    }
+
+  if (BE (dfa->nbackref, 0) && next_state != NULL)
+    {
+      /* Check OP_OPEN_SUBEXP in the current state in case that we use them
+	 later.  We must check them here, since the back references in the
+	 next state might use them.  */
+      *err = check_subexp_matching_top (mctx, &next_state->nodes,
+					cur_idx);
+      if (BE (*err != REG_NOERROR, 0))
+	return NULL;
+
+      /* If the next state has back references.  */
+      if (next_state->has_backref)
+	{
+	  *err = transit_state_bkref (mctx, &next_state->nodes);
+	  if (BE (*err != REG_NOERROR, 0))
+	    return NULL;
+	  next_state = mctx->state_log[cur_idx];
+	}
+    }
+
+  return next_state;
+}
+
+/* Skip bytes in the input that correspond to part of a
+   multi-byte match, then look in the log for a state
+   from which to restart matching.  */
+static re_dfastate_t *
+internal_function
+find_recover_state (reg_errcode_t *err, re_match_context_t *mctx)
+{
+  re_dfastate_t *cur_state;
+  do
+    {
+      Idx max = mctx->state_log_top;
+      Idx cur_str_idx = re_string_cur_idx (&mctx->input);
+
+      do
+	{
+          if (++cur_str_idx > max)
+            return NULL;
+          re_string_skip_bytes (&mctx->input, 1);
+	}
+      while (mctx->state_log[cur_str_idx] == NULL);
+
+      cur_state = merge_state_with_log (err, mctx, NULL);
+    }
+  while (*err == REG_NOERROR && cur_state == NULL);
+  return cur_state;
+}
+
+/* Helper functions for transit_state.  */
+
+/* From the node set CUR_NODES, pick up the nodes whose types are
+   OP_OPEN_SUBEXP and which have corresponding back references in the regular
+   expression. And register them to use them later for evaluating the
+   correspoding back references.  */
+
+static reg_errcode_t
+internal_function
+check_subexp_matching_top (re_match_context_t *mctx, re_node_set *cur_nodes,
+			   Idx str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx node_idx;
+  reg_errcode_t err;
+
+  /* TODO: This isn't efficient.
+	   Because there might be more than one nodes whose types are
+	   OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all
+	   nodes.
+	   E.g. RE: (a){2}  */
+  for (node_idx = 0; node_idx < cur_nodes->nelem; ++node_idx)
+    {
+      Idx node = cur_nodes->elems[node_idx];
+      if (dfa->nodes[node].type == OP_OPEN_SUBEXP
+	  && dfa->nodes[node].opr.idx < BITSET_WORD_BITS
+	  && (dfa->used_bkref_map
+	      & ((bitset_word_t) 1 << dfa->nodes[node].opr.idx)))
+	{
+	  err = match_ctx_add_subtop (mctx, node, str_idx);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+    }
+  return REG_NOERROR;
+}
+
+#if 0
+/* Return the next state to which the current state STATE will transit by
+   accepting the current input byte.  */
+
+static re_dfastate_t *
+transit_state_sb (reg_errcode_t *err, re_match_context_t *mctx,
+		  re_dfastate_t *state)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  re_node_set next_nodes;
+  re_dfastate_t *next_state;
+  Idx node_cnt, cur_str_idx = re_string_cur_idx (&mctx->input);
+  unsigned int context;
+
+  *err = re_node_set_alloc (&next_nodes, state->nodes.nelem + 1);
+  if (BE (*err != REG_NOERROR, 0))
+    return NULL;
+  for (node_cnt = 0; node_cnt < state->nodes.nelem; ++node_cnt)
+    {
+      Idx cur_node = state->nodes.elems[node_cnt];
+      if (check_node_accept (mctx, dfa->nodes + cur_node, cur_str_idx))
+	{
+	  *err = re_node_set_merge (&next_nodes,
+				    dfa->eclosures + dfa->nexts[cur_node]);
+	  if (BE (*err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return NULL;
+	    }
+	}
+    }
+  context = re_string_context_at (&mctx->input, cur_str_idx, mctx->eflags);
+  next_state = re_acquire_state_context (err, dfa, &next_nodes, context);
+  /* We don't need to check errors here, since the return value of
+     this function is next_state and ERR is already set.  */
+
+  re_node_set_free (&next_nodes);
+  re_string_skip_bytes (&mctx->input, 1);
+  return next_state;
+}
+#endif
+
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t
+internal_function
+transit_state_mb (re_match_context_t *mctx, re_dfastate_t *pstate)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx i;
+
+  for (i = 0; i < pstate->nodes.nelem; ++i)
+    {
+      re_node_set dest_nodes, *new_nodes;
+      Idx cur_node_idx = pstate->nodes.elems[i];
+      int naccepted;
+      Idx dest_idx;
+      unsigned int context;
+      re_dfastate_t *dest_state;
+
+      if (!dfa->nodes[cur_node_idx].accept_mb)
+        continue;
+
+      if (dfa->nodes[cur_node_idx].constraint)
+	{
+	  context = re_string_context_at (&mctx->input,
+					  re_string_cur_idx (&mctx->input),
+					  mctx->eflags);
+	  if (NOT_SATISFY_NEXT_CONSTRAINT (dfa->nodes[cur_node_idx].constraint,
+					   context))
+	    continue;
+	}
+
+      /* How many bytes the node can accept?  */
+      naccepted = check_node_accept_bytes (dfa, cur_node_idx, &mctx->input,
+					   re_string_cur_idx (&mctx->input));
+      if (naccepted == 0)
+	continue;
+
+      /* The node can accepts `naccepted' bytes.  */
+      dest_idx = re_string_cur_idx (&mctx->input) + naccepted;
+      mctx->max_mb_elem_len = ((mctx->max_mb_elem_len < naccepted) ? naccepted
+			       : mctx->max_mb_elem_len);
+      err = clean_state_log_if_needed (mctx, dest_idx);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+#ifdef DEBUG
+      assert (dfa->nexts[cur_node_idx] != REG_MISSING);
+#endif
+      new_nodes = dfa->eclosures + dfa->nexts[cur_node_idx];
+
+      dest_state = mctx->state_log[dest_idx];
+      if (dest_state == NULL)
+	dest_nodes = *new_nodes;
+      else
+	{
+	  err = re_node_set_init_union (&dest_nodes,
+					dest_state->entrance_nodes, new_nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+      context = re_string_context_at (&mctx->input, dest_idx - 1,
+				      mctx->eflags);
+      mctx->state_log[dest_idx]
+	= re_acquire_state_context (&err, dfa, &dest_nodes, context);
+      if (dest_state != NULL)
+	re_node_set_free (&dest_nodes);
+      if (BE (mctx->state_log[dest_idx] == NULL && err != REG_NOERROR, 0))
+	return err;
+    }
+  return REG_NOERROR;
+}
+#endif /* RE_ENABLE_I18N */
+
+static reg_errcode_t
+internal_function
+transit_state_bkref (re_match_context_t *mctx, const re_node_set *nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx i;
+  Idx cur_str_idx = re_string_cur_idx (&mctx->input);
+
+  for (i = 0; i < nodes->nelem; ++i)
+    {
+      Idx dest_str_idx, prev_nelem, bkc_idx;
+      Idx node_idx = nodes->elems[i];
+      unsigned int context;
+      const re_token_t *node = dfa->nodes + node_idx;
+      re_node_set *new_dest_nodes;
+
+      /* Check whether `node' is a backreference or not.  */
+      if (node->type != OP_BACK_REF)
+	continue;
+
+      if (node->constraint)
+	{
+	  context = re_string_context_at (&mctx->input, cur_str_idx,
+					  mctx->eflags);
+	  if (NOT_SATISFY_NEXT_CONSTRAINT (node->constraint, context))
+	    continue;
+	}
+
+      /* `node' is a backreference.
+	 Check the substring which the substring matched.  */
+      bkc_idx = mctx->nbkref_ents;
+      err = get_subexp (mctx, node_idx, cur_str_idx);
+      if (BE (err != REG_NOERROR, 0))
+	goto free_return;
+
+      /* And add the epsilon closures (which is `new_dest_nodes') of
+	 the backreference to appropriate state_log.  */
+#ifdef DEBUG
+      assert (dfa->nexts[node_idx] != REG_MISSING);
+#endif
+      for (; bkc_idx < mctx->nbkref_ents; ++bkc_idx)
+	{
+	  Idx subexp_len;
+	  re_dfastate_t *dest_state;
+	  struct re_backref_cache_entry *bkref_ent;
+	  bkref_ent = mctx->bkref_ents + bkc_idx;
+	  if (bkref_ent->node != node_idx || bkref_ent->str_idx != cur_str_idx)
+	    continue;
+	  subexp_len = bkref_ent->subexp_to - bkref_ent->subexp_from;
+	  new_dest_nodes = (subexp_len == 0
+			    ? dfa->eclosures + dfa->edests[node_idx].elems[0]
+			    : dfa->eclosures + dfa->nexts[node_idx]);
+	  dest_str_idx = (cur_str_idx + bkref_ent->subexp_to
+			  - bkref_ent->subexp_from);
+	  context = re_string_context_at (&mctx->input, dest_str_idx - 1,
+					  mctx->eflags);
+	  dest_state = mctx->state_log[dest_str_idx];
+	  prev_nelem = ((mctx->state_log[cur_str_idx] == NULL) ? 0
+			: mctx->state_log[cur_str_idx]->nodes.nelem);
+	  /* Add `new_dest_node' to state_log.  */
+	  if (dest_state == NULL)
+	    {
+	      mctx->state_log[dest_str_idx]
+		= re_acquire_state_context (&err, dfa, new_dest_nodes,
+					    context);
+	      if (BE (mctx->state_log[dest_str_idx] == NULL
+		      && err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  else
+	    {
+	      re_node_set dest_nodes;
+	      err = re_node_set_init_union (&dest_nodes,
+					    dest_state->entrance_nodes,
+					    new_dest_nodes);
+	      if (BE (err != REG_NOERROR, 0))
+		{
+		  re_node_set_free (&dest_nodes);
+		  goto free_return;
+		}
+	      mctx->state_log[dest_str_idx]
+		= re_acquire_state_context (&err, dfa, &dest_nodes, context);
+	      re_node_set_free (&dest_nodes);
+	      if (BE (mctx->state_log[dest_str_idx] == NULL
+		      && err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  /* We need to check recursively if the backreference can epsilon
+	     transit.  */
+	  if (subexp_len == 0
+	      && mctx->state_log[cur_str_idx]->nodes.nelem > prev_nelem)
+	    {
+	      err = check_subexp_matching_top (mctx, new_dest_nodes,
+					       cur_str_idx);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	      err = transit_state_bkref (mctx, new_dest_nodes);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	}
+    }
+  err = REG_NOERROR;
+ free_return:
+  return err;
+}
+
+/* Enumerate all the candidates which the backreference BKREF_NODE can match
+   at BKREF_STR_IDX, and register them by match_ctx_add_entry().
+   Note that we might collect inappropriate candidates here.
+   However, the cost of checking them strictly here is too high, then we
+   delay these checking for prune_impossible_nodes().  */
+
+static reg_errcode_t
+internal_function
+get_subexp (re_match_context_t *mctx, Idx bkref_node, Idx bkref_str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx subexp_num, sub_top_idx;
+  const char *buf = (const char *) re_string_get_buffer (&mctx->input);
+  /* Return if we have already checked BKREF_NODE at BKREF_STR_IDX.  */
+  Idx cache_idx = search_cur_bkref_entry (mctx, bkref_str_idx);
+  if (cache_idx != REG_MISSING)
+    {
+      const struct re_backref_cache_entry *entry
+	= mctx->bkref_ents + cache_idx;
+      do
+        if (entry->node == bkref_node)
+	  return REG_NOERROR; /* We already checked it.  */
+      while (entry++->more);
+    }
+
+  subexp_num = dfa->nodes[bkref_node].opr.idx;
+
+  /* For each sub expression  */
+  for (sub_top_idx = 0; sub_top_idx < mctx->nsub_tops; ++sub_top_idx)
+    {
+      reg_errcode_t err;
+      re_sub_match_top_t *sub_top = mctx->sub_tops[sub_top_idx];
+      re_sub_match_last_t *sub_last;
+      Idx sub_last_idx, sl_str, bkref_str_off;
+
+      if (dfa->nodes[sub_top->node].opr.idx != subexp_num)
+	continue; /* It isn't related.  */
+
+      sl_str = sub_top->str_idx;
+      bkref_str_off = bkref_str_idx;
+      /* At first, check the last node of sub expressions we already
+	 evaluated.  */
+      for (sub_last_idx = 0; sub_last_idx < sub_top->nlasts; ++sub_last_idx)
+	{
+	  regoff_t sl_str_diff;
+	  sub_last = sub_top->lasts[sub_last_idx];
+	  sl_str_diff = sub_last->str_idx - sl_str;
+	  /* The matched string by the sub expression match with the substring
+	     at the back reference?  */
+	  if (sl_str_diff > 0)
+	    {
+	      if (BE (bkref_str_off + sl_str_diff > mctx->input.valid_len, 0))
+		{
+		  /* Not enough chars for a successful match.  */
+		  if (bkref_str_off + sl_str_diff > mctx->input.len)
+		    break;
+
+		  err = clean_state_log_if_needed (mctx,
+						   bkref_str_off
+						   + sl_str_diff);
+		  if (BE (err != REG_NOERROR, 0))
+		    return err;
+		  buf = (const char *) re_string_get_buffer (&mctx->input);
+		}
+	      if (memcmp (buf + bkref_str_off, buf + sl_str, sl_str_diff) != 0)
+		/* We don't need to search this sub expression any more.  */
+		break;
+	    }
+	  bkref_str_off += sl_str_diff;
+	  sl_str += sl_str_diff;
+	  err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node,
+				bkref_str_idx);
+
+	  /* Reload buf, since the preceding call might have reallocated
+	     the buffer.  */
+	  buf = (const char *) re_string_get_buffer (&mctx->input);
+
+	  if (err == REG_NOMATCH)
+	    continue;
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+
+      if (sub_last_idx < sub_top->nlasts)
+	continue;
+      if (sub_last_idx > 0)
+	++sl_str;
+      /* Then, search for the other last nodes of the sub expression.  */
+      for (; sl_str <= bkref_str_idx; ++sl_str)
+	{
+	  Idx cls_node;
+	  regoff_t sl_str_off;
+	  const re_node_set *nodes;
+	  sl_str_off = sl_str - sub_top->str_idx;
+	  /* The matched string by the sub expression match with the substring
+	     at the back reference?  */
+	  if (sl_str_off > 0)
+	    {
+	      if (BE (bkref_str_off >= mctx->input.valid_len, 0))
+		{
+		  /* If we are at the end of the input, we cannot match.  */
+		  if (bkref_str_off >= mctx->input.len)
+		    break;
+
+		  err = extend_buffers (mctx);
+		  if (BE (err != REG_NOERROR, 0))
+		    return err;
+
+		  buf = (const char *) re_string_get_buffer (&mctx->input);
+		}
+	      if (buf [bkref_str_off++] != buf[sl_str - 1])
+		break; /* We don't need to search this sub expression
+			  any more.  */
+	    }
+	  if (mctx->state_log[sl_str] == NULL)
+	    continue;
+	  /* Does this state have a ')' of the sub expression?  */
+	  nodes = &mctx->state_log[sl_str]->nodes;
+	  cls_node = find_subexp_node (dfa, nodes, subexp_num,
+				       OP_CLOSE_SUBEXP);
+	  if (cls_node == REG_MISSING)
+	    continue; /* No.  */
+	  if (sub_top->path == NULL)
+	    {
+	      sub_top->path = calloc (sizeof (state_array_t),
+				      sl_str - sub_top->str_idx + 1);
+	      if (sub_top->path == NULL)
+		return REG_ESPACE;
+	    }
+	  /* Can the OP_OPEN_SUBEXP node arrive the OP_CLOSE_SUBEXP node
+	     in the current context?  */
+	  err = check_arrival (mctx, sub_top->path, sub_top->node,
+			       sub_top->str_idx, cls_node, sl_str,
+			       OP_CLOSE_SUBEXP);
+	  if (err == REG_NOMATCH)
+	      continue;
+	  if (BE (err != REG_NOERROR, 0))
+	      return err;
+	  sub_last = match_ctx_add_sublast (sub_top, cls_node, sl_str);
+	  if (BE (sub_last == NULL, 0))
+	    return REG_ESPACE;
+	  err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node,
+				bkref_str_idx);
+	  if (err == REG_NOMATCH)
+	    continue;
+	}
+    }
+  return REG_NOERROR;
+}
+
+/* Helper functions for get_subexp().  */
+
+/* Check SUB_LAST can arrive to the back reference BKREF_NODE at BKREF_STR.
+   If it can arrive, register the sub expression expressed with SUB_TOP
+   and SUB_LAST.  */
+
+static reg_errcode_t
+internal_function
+get_subexp_sub (re_match_context_t *mctx, const re_sub_match_top_t *sub_top,
+		re_sub_match_last_t *sub_last, Idx bkref_node, Idx bkref_str)
+{
+  reg_errcode_t err;
+  Idx to_idx;
+  /* Can the subexpression arrive the back reference?  */
+  err = check_arrival (mctx, &sub_last->path, sub_last->node,
+		       sub_last->str_idx, bkref_node, bkref_str,
+		       OP_OPEN_SUBEXP);
+  if (err != REG_NOERROR)
+    return err;
+  err = match_ctx_add_entry (mctx, bkref_node, bkref_str, sub_top->str_idx,
+			     sub_last->str_idx);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  to_idx = bkref_str + sub_last->str_idx - sub_top->str_idx;
+  return clean_state_log_if_needed (mctx, to_idx);
+}
+
+/* Find the first node which is '(' or ')' and whose index is SUBEXP_IDX.
+   Search '(' if FL_OPEN, or search ')' otherwise.
+   TODO: This function isn't efficient...
+	 Because there might be more than one nodes whose types are
+	 OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all
+	 nodes.
+	 E.g. RE: (a){2}  */
+
+static Idx
+internal_function
+find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes,
+		  Idx subexp_idx, int type)
+{
+  Idx cls_idx;
+  for (cls_idx = 0; cls_idx < nodes->nelem; ++cls_idx)
+    {
+      Idx cls_node = nodes->elems[cls_idx];
+      const re_token_t *node = dfa->nodes + cls_node;
+      if (node->type == type
+	  && node->opr.idx == subexp_idx)
+	return cls_node;
+    }
+  return REG_MISSING;
+}
+
+/* Check whether the node TOP_NODE at TOP_STR can arrive to the node
+   LAST_NODE at LAST_STR.  We record the path onto PATH since it will be
+   heavily reused.
+   Return REG_NOERROR if it can arrive, or REG_NOMATCH otherwise.  */
+
+static reg_errcode_t
+internal_function
+check_arrival (re_match_context_t *mctx, state_array_t *path, Idx top_node,
+	       Idx top_str, Idx last_node, Idx last_str, int type)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err = REG_NOERROR;
+  Idx subexp_num, backup_cur_idx, str_idx, null_cnt;
+  re_dfastate_t *cur_state = NULL;
+  re_node_set *cur_nodes, next_nodes;
+  re_dfastate_t **backup_state_log;
+  unsigned int context;
+
+  subexp_num = dfa->nodes[top_node].opr.idx;
+  /* Extend the buffer if we need.  */
+  if (BE (path->alloc < last_str + mctx->max_mb_elem_len + 1, 0))
+    {
+      re_dfastate_t **new_array;
+      Idx old_alloc = path->alloc;
+      Idx new_alloc = old_alloc + last_str + mctx->max_mb_elem_len + 1;
+      if (BE (new_alloc < old_alloc, 0)
+	  || BE (SIZE_MAX / sizeof (re_dfastate_t *) < new_alloc, 0))
+	return REG_ESPACE;
+      new_array = re_realloc (path->array, re_dfastate_t *, new_alloc);
+      if (BE (new_array == NULL, 0))
+	return REG_ESPACE;
+      path->array = new_array;
+      path->alloc = new_alloc;
+      memset (new_array + old_alloc, '\0',
+	      sizeof (re_dfastate_t *) * (path->alloc - old_alloc));
+    }
+
+  str_idx = path->next_idx ? path->next_idx : top_str;
+
+  /* Temporary modify MCTX.  */
+  backup_state_log = mctx->state_log;
+  backup_cur_idx = mctx->input.cur_idx;
+  mctx->state_log = path->array;
+  mctx->input.cur_idx = str_idx;
+
+  /* Setup initial node set.  */
+  context = re_string_context_at (&mctx->input, str_idx - 1, mctx->eflags);
+  if (str_idx == top_str)
+    {
+      err = re_node_set_init_1 (&next_nodes, top_node);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+      err = check_arrival_expand_ecl (dfa, &next_nodes, subexp_num, type);
+      if (BE (err != REG_NOERROR, 0))
+	{
+	  re_node_set_free (&next_nodes);
+	  return err;
+	}
+    }
+  else
+    {
+      cur_state = mctx->state_log[str_idx];
+      if (cur_state && cur_state->has_backref)
+	{
+	  err = re_node_set_init_copy (&next_nodes, &cur_state->nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+      else
+	re_node_set_init_empty (&next_nodes);
+    }
+  if (str_idx == top_str || (cur_state && cur_state->has_backref))
+    {
+      if (next_nodes.nelem)
+	{
+	  err = expand_bkref_cache (mctx, &next_nodes, str_idx,
+				    subexp_num, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      cur_state = re_acquire_state_context (&err, dfa, &next_nodes, context);
+      if (BE (cur_state == NULL && err != REG_NOERROR, 0))
+	{
+	  re_node_set_free (&next_nodes);
+	  return err;
+	}
+      mctx->state_log[str_idx] = cur_state;
+    }
+
+  for (null_cnt = 0; str_idx < last_str && null_cnt <= mctx->max_mb_elem_len;)
+    {
+      re_node_set_empty (&next_nodes);
+      if (mctx->state_log[str_idx + 1])
+	{
+	  err = re_node_set_merge (&next_nodes,
+				   &mctx->state_log[str_idx + 1]->nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      if (cur_state)
+	{
+	  err = check_arrival_add_next_nodes (mctx, str_idx,
+					      &cur_state->non_eps_nodes,
+					      &next_nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      ++str_idx;
+      if (next_nodes.nelem)
+	{
+	  err = check_arrival_expand_ecl (dfa, &next_nodes, subexp_num, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	  err = expand_bkref_cache (mctx, &next_nodes, str_idx,
+				    subexp_num, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      context = re_string_context_at (&mctx->input, str_idx - 1, mctx->eflags);
+      cur_state = re_acquire_state_context (&err, dfa, &next_nodes, context);
+      if (BE (cur_state == NULL && err != REG_NOERROR, 0))
+	{
+	  re_node_set_free (&next_nodes);
+	  return err;
+	}
+      mctx->state_log[str_idx] = cur_state;
+      null_cnt = cur_state == NULL ? null_cnt + 1 : 0;
+    }
+  re_node_set_free (&next_nodes);
+  cur_nodes = (mctx->state_log[last_str] == NULL ? NULL
+	       : &mctx->state_log[last_str]->nodes);
+  path->next_idx = str_idx;
+
+  /* Fix MCTX.  */
+  mctx->state_log = backup_state_log;
+  mctx->input.cur_idx = backup_cur_idx;
+
+  /* Then check the current node set has the node LAST_NODE.  */
+  if (cur_nodes != NULL && re_node_set_contains (cur_nodes, last_node))
+    return REG_NOERROR;
+
+  return REG_NOMATCH;
+}
+
+/* Helper functions for check_arrival.  */
+
+/* Calculate the destination nodes of CUR_NODES at STR_IDX, and append them
+   to NEXT_NODES.
+   TODO: This function is similar to the functions transit_state*(),
+	 however this function has many additional works.
+	 Can't we unify them?  */
+
+static reg_errcode_t
+internal_function
+check_arrival_add_next_nodes (re_match_context_t *mctx, Idx str_idx,
+			      re_node_set *cur_nodes, re_node_set *next_nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  bool ok;
+  Idx cur_idx;
+  reg_errcode_t err = REG_NOERROR;
+  re_node_set union_set;
+  re_node_set_init_empty (&union_set);
+  for (cur_idx = 0; cur_idx < cur_nodes->nelem; ++cur_idx)
+    {
+      int naccepted = 0;
+      Idx cur_node = cur_nodes->elems[cur_idx];
+#ifdef DEBUG
+      re_token_type_t type = dfa->nodes[cur_node].type;
+      assert (!IS_EPSILON_NODE (type));
+#endif
+#ifdef RE_ENABLE_I18N
+      /* If the node may accept `multi byte'.  */
+      if (dfa->nodes[cur_node].accept_mb)
+	{
+	  naccepted = check_node_accept_bytes (dfa, cur_node, &mctx->input,
+					       str_idx);
+	  if (naccepted > 1)
+	    {
+	      re_dfastate_t *dest_state;
+	      Idx next_node = dfa->nexts[cur_node];
+	      Idx next_idx = str_idx + naccepted;
+	      dest_state = mctx->state_log[next_idx];
+	      re_node_set_empty (&union_set);
+	      if (dest_state)
+		{
+		  err = re_node_set_merge (&union_set, &dest_state->nodes);
+		  if (BE (err != REG_NOERROR, 0))
+		    {
+		      re_node_set_free (&union_set);
+		      return err;
+		    }
+		}
+	      ok = re_node_set_insert (&union_set, next_node);
+	      if (BE (! ok, 0))
+		{
+		  re_node_set_free (&union_set);
+		  return REG_ESPACE;
+		}
+	      mctx->state_log[next_idx] = re_acquire_state (&err, dfa,
+							    &union_set);
+	      if (BE (mctx->state_log[next_idx] == NULL
+		      && err != REG_NOERROR, 0))
+		{
+		  re_node_set_free (&union_set);
+		  return err;
+		}
+	    }
+	}
+#endif /* RE_ENABLE_I18N */
+      if (naccepted
+	  || check_node_accept (mctx, dfa->nodes + cur_node, str_idx))
+	{
+	  ok = re_node_set_insert (next_nodes, dfa->nexts[cur_node]);
+	  if (BE (! ok, 0))
+	    {
+	      re_node_set_free (&union_set);
+	      return REG_ESPACE;
+	    }
+	}
+    }
+  re_node_set_free (&union_set);
+  return REG_NOERROR;
+}
+
+/* For all the nodes in CUR_NODES, add the epsilon closures of them to
+   CUR_NODES, however exclude the nodes which are:
+    - inside the sub expression whose number is EX_SUBEXP, if FL_OPEN.
+    - out of the sub expression whose number is EX_SUBEXP, if !FL_OPEN.
+*/
+
+static reg_errcode_t
+internal_function
+check_arrival_expand_ecl (const re_dfa_t *dfa, re_node_set *cur_nodes,
+			  Idx ex_subexp, int type)
+{
+  reg_errcode_t err;
+  Idx idx, outside_node;
+  re_node_set new_nodes;
+#ifdef DEBUG
+  assert (cur_nodes->nelem);
+#endif
+  err = re_node_set_alloc (&new_nodes, cur_nodes->nelem);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  /* Create a new node set NEW_NODES with the nodes which are epsilon
+     closures of the node in CUR_NODES.  */
+
+  for (idx = 0; idx < cur_nodes->nelem; ++idx)
+    {
+      Idx cur_node = cur_nodes->elems[idx];
+      const re_node_set *eclosure = dfa->eclosures + cur_node;
+      outside_node = find_subexp_node (dfa, eclosure, ex_subexp, type);
+      if (outside_node == REG_MISSING)
+	{
+	  /* There are no problematic nodes, just merge them.  */
+	  err = re_node_set_merge (&new_nodes, eclosure);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&new_nodes);
+	      return err;
+	    }
+	}
+      else
+	{
+	  /* There are problematic nodes, re-calculate incrementally.  */
+	  err = check_arrival_expand_ecl_sub (dfa, &new_nodes, cur_node,
+					      ex_subexp, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&new_nodes);
+	      return err;
+	    }
+	}
+    }
+  re_node_set_free (cur_nodes);
+  *cur_nodes = new_nodes;
+  return REG_NOERROR;
+}
+
+/* Helper function for check_arrival_expand_ecl.
+   Check incrementally the epsilon closure of TARGET, and if it isn't
+   problematic append it to DST_NODES.  */
+
+static reg_errcode_t
+internal_function
+check_arrival_expand_ecl_sub (const re_dfa_t *dfa, re_node_set *dst_nodes,
+			      Idx target, Idx ex_subexp, int type)
+{
+  Idx cur_node;
+  for (cur_node = target; !re_node_set_contains (dst_nodes, cur_node);)
+    {
+      bool ok;
+
+      if (dfa->nodes[cur_node].type == type
+	  && dfa->nodes[cur_node].opr.idx == ex_subexp)
+	{
+	  if (type == OP_CLOSE_SUBEXP)
+	    {
+	      ok = re_node_set_insert (dst_nodes, cur_node);
+	      if (BE (! ok, 0))
+		return REG_ESPACE;
+	    }
+	  break;
+	}
+      ok = re_node_set_insert (dst_nodes, cur_node);
+      if (BE (! ok, 0))
+	return REG_ESPACE;
+      if (dfa->edests[cur_node].nelem == 0)
+	break;
+      if (dfa->edests[cur_node].nelem == 2)
+	{
+	  reg_errcode_t err;
+	  err = check_arrival_expand_ecl_sub (dfa, dst_nodes,
+					      dfa->edests[cur_node].elems[1],
+					      ex_subexp, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+      cur_node = dfa->edests[cur_node].elems[0];
+    }
+  return REG_NOERROR;
+}
+
+
+/* For all the back references in the current state, calculate the
+   destination of the back references by the appropriate entry
+   in MCTX->BKREF_ENTS.  */
+
+static reg_errcode_t
+internal_function
+expand_bkref_cache (re_match_context_t *mctx, re_node_set *cur_nodes,
+		    Idx cur_str, Idx subexp_num, int type)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx cache_idx_start = search_cur_bkref_entry (mctx, cur_str);
+  struct re_backref_cache_entry *ent;
+
+  if (cache_idx_start == REG_MISSING)
+    return REG_NOERROR;
+
+ restart:
+  ent = mctx->bkref_ents + cache_idx_start;
+  do
+    {
+      Idx to_idx, next_node;
+
+      /* Is this entry ENT is appropriate?  */
+      if (!re_node_set_contains (cur_nodes, ent->node))
+	continue; /* No.  */
+
+      to_idx = cur_str + ent->subexp_to - ent->subexp_from;
+      /* Calculate the destination of the back reference, and append it
+	 to MCTX->STATE_LOG.  */
+      if (to_idx == cur_str)
+	{
+	  /* The backreference did epsilon transit, we must re-check all the
+	     node in the current state.  */
+	  re_node_set new_dests;
+	  reg_errcode_t err2, err3;
+	  next_node = dfa->edests[ent->node].elems[0];
+	  if (re_node_set_contains (cur_nodes, next_node))
+	    continue;
+	  err = re_node_set_init_1 (&new_dests, next_node);
+	  err2 = check_arrival_expand_ecl (dfa, &new_dests, subexp_num, type);
+	  err3 = re_node_set_merge (cur_nodes, &new_dests);
+	  re_node_set_free (&new_dests);
+	  if (BE (err != REG_NOERROR || err2 != REG_NOERROR
+		  || err3 != REG_NOERROR, 0))
+	    {
+	      err = (err != REG_NOERROR ? err
+		     : (err2 != REG_NOERROR ? err2 : err3));
+	      return err;
+	    }
+	  /* TODO: It is still inefficient...  */
+	  goto restart;
+	}
+      else
+	{
+	  re_node_set union_set;
+	  next_node = dfa->nexts[ent->node];
+	  if (mctx->state_log[to_idx])
+	    {
+	      bool ok;
+	      if (re_node_set_contains (&mctx->state_log[to_idx]->nodes,
+					next_node))
+		continue;
+	      err = re_node_set_init_copy (&union_set,
+					   &mctx->state_log[to_idx]->nodes);
+	      ok = re_node_set_insert (&union_set, next_node);
+	      if (BE (err != REG_NOERROR || ! ok, 0))
+		{
+		  re_node_set_free (&union_set);
+		  err = err != REG_NOERROR ? err : REG_ESPACE;
+		  return err;
+		}
+	    }
+	  else
+	    {
+	      err = re_node_set_init_1 (&union_set, next_node);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+	  mctx->state_log[to_idx] = re_acquire_state (&err, dfa, &union_set);
+	  re_node_set_free (&union_set);
+	  if (BE (mctx->state_log[to_idx] == NULL
+		  && err != REG_NOERROR, 0))
+	    return err;
+	}
+    }
+  while (ent++->more);
+  return REG_NOERROR;
+}
+
+/* Build transition table for the state.
+   Return true if successful.  */
+
+static bool
+internal_function
+build_trtable (const re_dfa_t *dfa, re_dfastate_t *state)
+{
+  reg_errcode_t err;
+  Idx i, j;
+  int ch;
+  bool need_word_trtable = false;
+  bitset_word_t elem, mask;
+  bool dests_node_malloced = false;
+  bool dest_states_malloced = false;
+  Idx ndests; /* Number of the destination states from `state'.  */
+  re_dfastate_t **trtable;
+  re_dfastate_t **dest_states = NULL, **dest_states_word, **dest_states_nl;
+  re_node_set follows, *dests_node;
+  bitset_t *dests_ch;
+  bitset_t acceptable;
+
+  struct dests_alloc
+  {
+    re_node_set dests_node[SBC_MAX];
+    bitset_t dests_ch[SBC_MAX];
+  } *dests_alloc;
+
+  /* We build DFA states which corresponds to the destination nodes
+     from `state'.  `dests_node[i]' represents the nodes which i-th
+     destination state contains, and `dests_ch[i]' represents the
+     characters which i-th destination state accepts.  */
+  if (__libc_use_alloca (sizeof (struct dests_alloc)))
+    dests_alloc = (struct dests_alloc *) alloca (sizeof (struct dests_alloc));
+  else
+    {
+      dests_alloc = re_malloc (struct dests_alloc, 1);
+      if (BE (dests_alloc == NULL, 0))
+	return false;
+      dests_node_malloced = true;
+    }
+  dests_node = dests_alloc->dests_node;
+  dests_ch = dests_alloc->dests_ch;
+
+  /* Initialize transiton table.  */
+  state->word_trtable = state->trtable = NULL;
+
+  /* At first, group all nodes belonging to `state' into several
+     destinations.  */
+  ndests = group_nodes_into_DFAstates (dfa, state, dests_node, dests_ch);
+  if (BE (! REG_VALID_NONZERO_INDEX (ndests), 0))
+    {
+      if (dests_node_malloced)
+	free (dests_alloc);
+      if (ndests == 0)
+	{
+	  state->trtable = (re_dfastate_t **)
+	    calloc (sizeof (re_dfastate_t *), SBC_MAX);
+	  return true;
+	}
+      return false;
+    }
+
+  err = re_node_set_alloc (&follows, ndests + 1);
+  if (BE (err != REG_NOERROR, 0))
+    goto out_free;
+
+  /* Avoid arithmetic overflow in size calculation.  */
+  if (BE ((((SIZE_MAX - (sizeof (re_node_set) + sizeof (bitset_t)) * SBC_MAX)
+	    / (3 * sizeof (re_dfastate_t *)))
+	   < ndests),
+	  0))
+    goto out_free;
+
+  if (__libc_use_alloca ((sizeof (re_node_set) + sizeof (bitset_t)) * SBC_MAX
+			 + ndests * 3 * sizeof (re_dfastate_t *)))
+    dest_states = (re_dfastate_t **)
+      alloca (ndests * 3 * sizeof (re_dfastate_t *));
+  else
+    {
+      dest_states = (re_dfastate_t **)
+	malloc (ndests * 3 * sizeof (re_dfastate_t *));
+      if (BE (dest_states == NULL, 0))
+	{
+out_free:
+	  if (dest_states_malloced)
+	    free (dest_states);
+	  re_node_set_free (&follows);
+	  for (i = 0; i < ndests; ++i)
+	    re_node_set_free (dests_node + i);
+	  if (dests_node_malloced)
+	    free (dests_alloc);
+	  return false;
+	}
+      dest_states_malloced = true;
+    }
+  dest_states_word = dest_states + ndests;
+  dest_states_nl = dest_states_word + ndests;
+  bitset_empty (acceptable);
+
+  /* Then build the states for all destinations.  */
+  for (i = 0; i < ndests; ++i)
+    {
+      Idx next_node;
+      re_node_set_empty (&follows);
+      /* Merge the follows of this destination states.  */
+      for (j = 0; j < dests_node[i].nelem; ++j)
+	{
+	  next_node = dfa->nexts[dests_node[i].elems[j]];
+	  if (next_node != REG_MISSING)
+	    {
+	      err = re_node_set_merge (&follows, dfa->eclosures + next_node);
+	      if (BE (err != REG_NOERROR, 0))
+		goto out_free;
+	    }
+	}
+      dest_states[i] = re_acquire_state_context (&err, dfa, &follows, 0);
+      if (BE (dest_states[i] == NULL && err != REG_NOERROR, 0))
+	goto out_free;
+      /* If the new state has context constraint,
+	 build appropriate states for these contexts.  */
+      if (dest_states[i]->has_constraint)
+	{
+	  dest_states_word[i] = re_acquire_state_context (&err, dfa, &follows,
+							  CONTEXT_WORD);
+	  if (BE (dest_states_word[i] == NULL && err != REG_NOERROR, 0))
+	    goto out_free;
+
+	  if (dest_states[i] != dest_states_word[i] && dfa->mb_cur_max > 1)
+	    need_word_trtable = true;
+
+	  dest_states_nl[i] = re_acquire_state_context (&err, dfa, &follows,
+							CONTEXT_NEWLINE);
+	  if (BE (dest_states_nl[i] == NULL && err != REG_NOERROR, 0))
+	    goto out_free;
+ 	}
+      else
+	{
+	  dest_states_word[i] = dest_states[i];
+	  dest_states_nl[i] = dest_states[i];
+	}
+      bitset_merge (acceptable, dests_ch[i]);
+    }
+
+  if (!BE (need_word_trtable, 0))
+    {
+      /* We don't care about whether the following character is a word
+	 character, or we are in a single-byte character set so we can
+	 discern by looking at the character code: allocate a
+	 256-entry transition table.  */
+      trtable = state->trtable =
+	(re_dfastate_t **) calloc (sizeof (re_dfastate_t *), SBC_MAX);
+      if (BE (trtable == NULL, 0))
+	goto out_free;
+
+      /* For all characters ch...:  */
+      for (i = 0; i < BITSET_WORDS; ++i)
+	for (ch = i * BITSET_WORD_BITS, elem = acceptable[i], mask = 1;
+	     elem;
+	     mask <<= 1, elem >>= 1, ++ch)
+	  if (BE (elem & 1, 0))
+	    {
+	      /* There must be exactly one destination which accepts
+		 character ch.  See group_nodes_into_DFAstates.  */
+	      for (j = 0; (dests_ch[j][i] & mask) == 0; ++j)
+		;
+
+	      /* j-th destination accepts the word character ch.  */
+	      if (dfa->word_char[i] & mask)
+		trtable[ch] = dest_states_word[j];
+	      else
+		trtable[ch] = dest_states[j];
+	    }
+    }
+  else
+    {
+      /* We care about whether the following character is a word
+	 character, and we are in a multi-byte character set: discern
+	 by looking at the character code: build two 256-entry
+	 transition tables, one starting at trtable[0] and one
+	 starting at trtable[SBC_MAX].  */
+      trtable = state->word_trtable =
+	(re_dfastate_t **) calloc (sizeof (re_dfastate_t *), 2 * SBC_MAX);
+      if (BE (trtable == NULL, 0))
+	goto out_free;
+
+      /* For all characters ch...:  */
+      for (i = 0; i < BITSET_WORDS; ++i)
+	for (ch = i * BITSET_WORD_BITS, elem = acceptable[i], mask = 1;
+	     elem;
+	     mask <<= 1, elem >>= 1, ++ch)
+	  if (BE (elem & 1, 0))
+	    {
+	      /* There must be exactly one destination which accepts
+		 character ch.  See group_nodes_into_DFAstates.  */
+	      for (j = 0; (dests_ch[j][i] & mask) == 0; ++j)
+		;
+
+	      /* j-th destination accepts the word character ch.  */
+	      trtable[ch] = dest_states[j];
+	      trtable[ch + SBC_MAX] = dest_states_word[j];
+	    }
+    }
+
+  /* new line */
+  if (bitset_contain (acceptable, NEWLINE_CHAR))
+    {
+      /* The current state accepts newline character.  */
+      for (j = 0; j < ndests; ++j)
+	if (bitset_contain (dests_ch[j], NEWLINE_CHAR))
+	  {
+	    /* k-th destination accepts newline character.  */
+	    trtable[NEWLINE_CHAR] = dest_states_nl[j];
+	    if (need_word_trtable)
+	      trtable[NEWLINE_CHAR + SBC_MAX] = dest_states_nl[j];
+	    /* There must be only one destination which accepts
+	       newline.  See group_nodes_into_DFAstates.  */
+	    break;
+	  }
+    }
+
+  if (dest_states_malloced)
+    free (dest_states);
+
+  re_node_set_free (&follows);
+  for (i = 0; i < ndests; ++i)
+    re_node_set_free (dests_node + i);
+
+  if (dests_node_malloced)
+    free (dests_alloc);
+
+  return true;
+}
+
+/* Group all nodes belonging to STATE into several destinations.
+   Then for all destinations, set the nodes belonging to the destination
+   to DESTS_NODE[i] and set the characters accepted by the destination
+   to DEST_CH[i].  This function return the number of destinations.  */
+
+static Idx
+internal_function
+group_nodes_into_DFAstates (const re_dfa_t *dfa, const re_dfastate_t *state,
+			    re_node_set *dests_node, bitset_t *dests_ch)
+{
+  reg_errcode_t err;
+  bool ok;
+  Idx i, j, k;
+  Idx ndests; /* Number of the destinations from `state'.  */
+  bitset_t accepts; /* Characters a node can accept.  */
+  const re_node_set *cur_nodes = &state->nodes;
+  bitset_empty (accepts);
+  ndests = 0;
+
+  /* For all the nodes belonging to `state',  */
+  for (i = 0; i < cur_nodes->nelem; ++i)
+    {
+      re_token_t *node = &dfa->nodes[cur_nodes->elems[i]];
+      re_token_type_t type = node->type;
+      unsigned int constraint = node->constraint;
+
+      /* Enumerate all single byte character this node can accept.  */
+      if (type == CHARACTER)
+	bitset_set (accepts, node->opr.c);
+      else if (type == SIMPLE_BRACKET)
+	{
+	  bitset_merge (accepts, node->opr.sbcset);
+	}
+      else if (type == OP_PERIOD)
+	{
+#ifdef RE_ENABLE_I18N
+	  if (dfa->mb_cur_max > 1)
+	    bitset_merge (accepts, dfa->sb_char);
+	  else
+#endif
+	    bitset_set_all (accepts);
+	  if (!(dfa->syntax & RE_DOT_NEWLINE))
+	    bitset_clear (accepts, '\n');
+	  if (dfa->syntax & RE_DOT_NOT_NULL)
+	    bitset_clear (accepts, '\0');
+	}
+#ifdef RE_ENABLE_I18N
+      else if (type == OP_UTF8_PERIOD)
+        {
+	  if (ASCII_CHARS % BITSET_WORD_BITS == 0)
+	    memset (accepts, -1, ASCII_CHARS / CHAR_BIT);
+	  else
+	    bitset_merge (accepts, utf8_sb_map);
+	  if (!(dfa->syntax & RE_DOT_NEWLINE))
+	    bitset_clear (accepts, '\n');
+	  if (dfa->syntax & RE_DOT_NOT_NULL)
+	    bitset_clear (accepts, '\0');
+        }
+#endif
+      else
+	continue;
+
+      /* Check the `accepts' and sift the characters which are not
+	 match it the context.  */
+      if (constraint)
+	{
+	  if (constraint & NEXT_NEWLINE_CONSTRAINT)
+	    {
+	      bool accepts_newline = bitset_contain (accepts, NEWLINE_CHAR);
+	      bitset_empty (accepts);
+	      if (accepts_newline)
+		bitset_set (accepts, NEWLINE_CHAR);
+	      else
+		continue;
+	    }
+	  if (constraint & NEXT_ENDBUF_CONSTRAINT)
+	    {
+	      bitset_empty (accepts);
+	      continue;
+	    }
+
+	  if (constraint & NEXT_WORD_CONSTRAINT)
+	    {
+	      bitset_word_t any_set = 0;
+	      if (type == CHARACTER && !node->word_char)
+		{
+		  bitset_empty (accepts);
+		  continue;
+		}
+#ifdef RE_ENABLE_I18N
+	      if (dfa->mb_cur_max > 1)
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= (dfa->word_char[j] | ~dfa->sb_char[j]));
+	      else
+#endif
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= dfa->word_char[j]);
+	      if (!any_set)
+		continue;
+	    }
+	  if (constraint & NEXT_NOTWORD_CONSTRAINT)
+	    {
+	      bitset_word_t any_set = 0;
+	      if (type == CHARACTER && node->word_char)
+		{
+		  bitset_empty (accepts);
+		  continue;
+		}
+#ifdef RE_ENABLE_I18N
+	      if (dfa->mb_cur_max > 1)
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= ~(dfa->word_char[j] & dfa->sb_char[j]));
+	      else
+#endif
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= ~dfa->word_char[j]);
+	      if (!any_set)
+		continue;
+	    }
+	}
+
+      /* Then divide `accepts' into DFA states, or create a new
+	 state.  Above, we make sure that accepts is not empty.  */
+      for (j = 0; j < ndests; ++j)
+	{
+	  bitset_t intersec; /* Intersection sets, see below.  */
+	  bitset_t remains;
+	  /* Flags, see below.  */
+	  bitset_word_t has_intersec, not_subset, not_consumed;
+
+	  /* Optimization, skip if this state doesn't accept the character.  */
+	  if (type == CHARACTER && !bitset_contain (dests_ch[j], node->opr.c))
+	    continue;
+
+	  /* Enumerate the intersection set of this state and `accepts'.  */
+	  has_intersec = 0;
+	  for (k = 0; k < BITSET_WORDS; ++k)
+	    has_intersec |= intersec[k] = accepts[k] & dests_ch[j][k];
+	  /* And skip if the intersection set is empty.  */
+	  if (!has_intersec)
+	    continue;
+
+	  /* Then check if this state is a subset of `accepts'.  */
+	  not_subset = not_consumed = 0;
+	  for (k = 0; k < BITSET_WORDS; ++k)
+	    {
+	      not_subset |= remains[k] = ~accepts[k] & dests_ch[j][k];
+	      not_consumed |= accepts[k] = accepts[k] & ~dests_ch[j][k];
+	    }
+
+	  /* If this state isn't a subset of `accepts', create a
+	     new group state, which has the `remains'. */
+	  if (not_subset)
+	    {
+	      bitset_copy (dests_ch[ndests], remains);
+	      bitset_copy (dests_ch[j], intersec);
+	      err = re_node_set_init_copy (dests_node + ndests, &dests_node[j]);
+	      if (BE (err != REG_NOERROR, 0))
+		goto error_return;
+	      ++ndests;
+	    }
+
+	  /* Put the position in the current group. */
+	  ok = re_node_set_insert (&dests_node[j], cur_nodes->elems[i]);
+	  if (BE (! ok, 0))
+	    goto error_return;
+
+	  /* If all characters are consumed, go to next node. */
+	  if (!not_consumed)
+	    break;
+	}
+      /* Some characters remain, create a new group. */
+      if (j == ndests)
+	{
+	  bitset_copy (dests_ch[ndests], accepts);
+	  err = re_node_set_init_1 (dests_node + ndests, cur_nodes->elems[i]);
+	  if (BE (err != REG_NOERROR, 0))
+	    goto error_return;
+	  ++ndests;
+	  bitset_empty (accepts);
+	}
+    }
+  return ndests;
+ error_return:
+  for (j = 0; j < ndests; ++j)
+    re_node_set_free (dests_node + j);
+  return REG_MISSING;
+}
+
+#ifdef RE_ENABLE_I18N
+/* Check how many bytes the node `dfa->nodes[node_idx]' accepts.
+   Return the number of the bytes the node accepts.
+   STR_IDX is the current index of the input string.
+
+   This function handles the nodes which can accept one character, or
+   one collating element like '.', '[a-z]', opposite to the other nodes
+   can only accept one byte.  */
+
+static int
+internal_function
+check_node_accept_bytes (const re_dfa_t *dfa, Idx node_idx,
+			 const re_string_t *input, Idx str_idx)
+{
+  const re_token_t *node = dfa->nodes + node_idx;
+  int char_len, elem_len;
+  Idx i;
+
+  if (BE (node->type == OP_UTF8_PERIOD, 0))
+    {
+      unsigned char c = re_string_byte_at (input, str_idx), d;
+      if (BE (c < 0xc2, 1))
+	return 0;
+
+      if (str_idx + 2 > input->len)
+	return 0;
+
+      d = re_string_byte_at (input, str_idx + 1);
+      if (c < 0xe0)
+	return (d < 0x80 || d > 0xbf) ? 0 : 2;
+      else if (c < 0xf0)
+	{
+	  char_len = 3;
+	  if (c == 0xe0 && d < 0xa0)
+	    return 0;
+	}
+      else if (c < 0xf8)
+	{
+	  char_len = 4;
+	  if (c == 0xf0 && d < 0x90)
+	    return 0;
+	}
+      else if (c < 0xfc)
+	{
+	  char_len = 5;
+	  if (c == 0xf8 && d < 0x88)
+	    return 0;
+	}
+      else if (c < 0xfe)
+	{
+	  char_len = 6;
+	  if (c == 0xfc && d < 0x84)
+	    return 0;
+	}
+      else
+	return 0;
+
+      if (str_idx + char_len > input->len)
+	return 0;
+
+      for (i = 1; i < char_len; ++i)
+	{
+	  d = re_string_byte_at (input, str_idx + i);
+	  if (d < 0x80 || d > 0xbf)
+	    return 0;
+	}
+      return char_len;
+    }
+
+  char_len = re_string_char_size_at (input, str_idx);
+  if (node->type == OP_PERIOD)
+    {
+      if (char_len <= 1)
+        return 0;
+      /* FIXME: I don't think this if is needed, as both '\n'
+	 and '\0' are char_len == 1.  */
+      /* '.' accepts any one character except the following two cases.  */
+      if ((!(dfa->syntax & RE_DOT_NEWLINE) &&
+	   re_string_byte_at (input, str_idx) == '\n') ||
+	  ((dfa->syntax & RE_DOT_NOT_NULL) &&
+	   re_string_byte_at (input, str_idx) == '\0'))
+	return 0;
+      return char_len;
+    }
+
+  elem_len = re_string_elem_size_at (input, str_idx);
+  if ((elem_len <= 1 && char_len <= 1) || char_len == 0)
+    return 0;
+
+  if (node->type == COMPLEX_BRACKET)
+    {
+      const re_charset_t *cset = node->opr.mbcset;
+# ifdef _LIBC
+      const unsigned char *pin
+	= ((const unsigned char *) re_string_get_buffer (input) + str_idx);
+      Idx j;
+      uint32_t nrules;
+# endif /* _LIBC */
+      int match_len = 0;
+      wchar_t wc = ((cset->nranges || cset->nchar_classes || cset->nmbchars)
+		    ? re_string_wchar_at (input, str_idx) : 0);
+
+      /* match with multibyte character?  */
+      for (i = 0; i < cset->nmbchars; ++i)
+	if (wc == cset->mbchars[i])
+	  {
+	    match_len = char_len;
+	    goto check_node_accept_bytes_match;
+	  }
+      /* match with character_class?  */
+      for (i = 0; i < cset->nchar_classes; ++i)
+	{
+	  wctype_t wt = cset->char_classes[i];
+	  if (__iswctype (wc, wt))
+	    {
+	      match_len = char_len;
+	      goto check_node_accept_bytes_match;
+	    }
+	}
+
+# ifdef _LIBC
+      nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+      if (nrules != 0)
+	{
+	  unsigned int in_collseq = 0;
+	  const int32_t *table, *indirect;
+	  const unsigned char *weights, *extra;
+	  const char *collseqwc;
+	  int32_t idx;
+	  /* This #include defines a local function!  */
+#  include <locale/weight.h>
+
+	  /* match with collating_symbol?  */
+	  if (cset->ncoll_syms)
+	    extra = (const unsigned char *)
+	      _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+	  for (i = 0; i < cset->ncoll_syms; ++i)
+	    {
+	      const unsigned char *coll_sym = extra + cset->coll_syms[i];
+	      /* Compare the length of input collating element and
+		 the length of current collating element.  */
+	      if (*coll_sym != elem_len)
+		continue;
+	      /* Compare each bytes.  */
+	      for (j = 0; j < *coll_sym; j++)
+		if (pin[j] != coll_sym[1 + j])
+		  break;
+	      if (j == *coll_sym)
+		{
+		  /* Match if every bytes is equal.  */
+		  match_len = j;
+		  goto check_node_accept_bytes_match;
+		}
+	    }
+
+	  if (cset->nranges)
+	    {
+	      if (elem_len <= char_len)
+		{
+		  collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+		  in_collseq = __collseq_table_lookup (collseqwc, wc);
+		}
+	      else
+		in_collseq = find_collation_sequence_value (pin, elem_len);
+	    }
+	  /* match with range expression?  */
+	  for (i = 0; i < cset->nranges; ++i)
+	    if (cset->range_starts[i] <= in_collseq
+		&& in_collseq <= cset->range_ends[i])
+	      {
+		match_len = elem_len;
+		goto check_node_accept_bytes_match;
+	      }
+
+	  /* match with equivalence_class?  */
+	  if (cset->nequiv_classes)
+	    {
+	      const unsigned char *cp = pin;
+	      table = (const int32_t *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+	      weights = (const unsigned char *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_WEIGHTMB);
+	      extra = (const unsigned char *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAMB);
+	      indirect = (const int32_t *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_INDIRECTMB);
+	      idx = findidx (&cp);
+	      if (idx > 0)
+		for (i = 0; i < cset->nequiv_classes; ++i)
+		  {
+		    int32_t equiv_class_idx = cset->equiv_classes[i];
+		    size_t weight_len = weights[idx];
+		    if (weight_len == weights[equiv_class_idx])
+		      {
+			Idx cnt = 0;
+			while (cnt <= weight_len
+			       && (weights[equiv_class_idx + 1 + cnt]
+				   == weights[idx + 1 + cnt]))
+			  ++cnt;
+			if (cnt > weight_len)
+			  {
+			    match_len = elem_len;
+			    goto check_node_accept_bytes_match;
+			  }
+		      }
+		  }
+	    }
+	}
+      else
+# endif /* _LIBC */
+	{
+	  /* match with range expression?  */
+#if __GNUC__ >= 2
+	  wchar_t cmp_buf[] = {L'\0', L'\0', wc, L'\0', L'\0', L'\0'};
+#else
+	  wchar_t cmp_buf[] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
+	  cmp_buf[2] = wc;
+#endif
+	  for (i = 0; i < cset->nranges; ++i)
+	    {
+	      cmp_buf[0] = cset->range_starts[i];
+	      cmp_buf[4] = cset->range_ends[i];
+	      if (wcscoll (cmp_buf, cmp_buf + 2) <= 0
+		  && wcscoll (cmp_buf + 2, cmp_buf + 4) <= 0)
+		{
+		  match_len = char_len;
+		  goto check_node_accept_bytes_match;
+		}
+	    }
+	}
+    check_node_accept_bytes_match:
+      if (!cset->non_match)
+	return match_len;
+      else
+	{
+	  if (match_len > 0)
+	    return 0;
+	  else
+	    return (elem_len > char_len) ? elem_len : char_len;
+	}
+    }
+  return 0;
+}
+
+# ifdef _LIBC
+static unsigned int
+internal_function
+find_collation_sequence_value (const unsigned char *mbs, size_t mbs_len)
+{
+  uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules == 0)
+    {
+      if (mbs_len == 1)
+	{
+	  /* No valid character.  Match it as a single byte character.  */
+	  const unsigned char *collseq = (const unsigned char *)
+	    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
+	  return collseq[mbs[0]];
+	}
+      return UINT_MAX;
+    }
+  else
+    {
+      int32_t idx;
+      const unsigned char *extra = (const unsigned char *)
+	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+      int32_t extrasize = (const unsigned char *)
+	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB + 1) - extra;
+
+      for (idx = 0; idx < extrasize;)
+	{
+	  int mbs_cnt;
+	  bool found = false;
+	  int32_t elem_mbs_len;
+	  /* Skip the name of collating element name.  */
+	  idx = idx + extra[idx] + 1;
+	  elem_mbs_len = extra[idx++];
+	  if (mbs_len == elem_mbs_len)
+	    {
+	      for (mbs_cnt = 0; mbs_cnt < elem_mbs_len; ++mbs_cnt)
+		if (extra[idx + mbs_cnt] != mbs[mbs_cnt])
+		  break;
+	      if (mbs_cnt == elem_mbs_len)
+		/* Found the entry.  */
+		found = true;
+	    }
+	  /* Skip the byte sequence of the collating element.  */
+	  idx += elem_mbs_len;
+	  /* Adjust for the alignment.  */
+	  idx = (idx + 3) & ~3;
+	  /* Skip the collation sequence value.  */
+	  idx += sizeof (uint32_t);
+	  /* Skip the wide char sequence of the collating element.  */
+	  idx = idx + sizeof (uint32_t) * (extra[idx] + 1);
+	  /* If we found the entry, return the sequence value.  */
+	  if (found)
+	    return *(uint32_t *) (extra + idx);
+	  /* Skip the collation sequence value.  */
+	  idx += sizeof (uint32_t);
+	}
+      return UINT_MAX;
+    }
+}
+# endif /* _LIBC */
+#endif /* RE_ENABLE_I18N */
+
+/* Check whether the node accepts the byte which is IDX-th
+   byte of the INPUT.  */
+
+static bool
+internal_function
+check_node_accept (const re_match_context_t *mctx, const re_token_t *node,
+		   Idx idx)
+{
+  unsigned char ch;
+  ch = re_string_byte_at (&mctx->input, idx);
+  switch (node->type)
+    {
+    case CHARACTER:
+      if (node->opr.c != ch)
+        return false;
+      break;
+
+    case SIMPLE_BRACKET:
+      if (!bitset_contain (node->opr.sbcset, ch))
+        return false;
+      break;
+
+#ifdef RE_ENABLE_I18N
+    case OP_UTF8_PERIOD:
+      if (ch >= ASCII_CHARS)
+        return false;
+      /* FALLTHROUGH */
+#endif
+    case OP_PERIOD:
+      if ((ch == '\n' && !(mctx->dfa->syntax & RE_DOT_NEWLINE))
+	  || (ch == '\0' && (mctx->dfa->syntax & RE_DOT_NOT_NULL)))
+	return false;
+      break;
+
+    default:
+      return false;
+    }
+
+  if (node->constraint)
+    {
+      /* The node has constraints.  Check whether the current context
+	 satisfies the constraints.  */
+      unsigned int context = re_string_context_at (&mctx->input, idx,
+						   mctx->eflags);
+      if (NOT_SATISFY_NEXT_CONSTRAINT (node->constraint, context))
+	return false;
+    }
+
+  return true;
+}
+
+/* Extend the buffers, if the buffers have run out.  */
+
+static reg_errcode_t
+internal_function
+extend_buffers (re_match_context_t *mctx)
+{
+  reg_errcode_t ret;
+  re_string_t *pstr = &mctx->input;
+
+  /* Avoid overflow.  */
+  if (BE (SIZE_MAX / 2 / sizeof (re_dfastate_t *) <= pstr->bufs_len, 0))
+    return REG_ESPACE;
+
+  /* Double the lengthes of the buffers.  */
+  ret = re_string_realloc_buffers (pstr, pstr->bufs_len * 2);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  if (mctx->state_log != NULL)
+    {
+      /* And double the length of state_log.  */
+      /* XXX We have no indication of the size of this buffer.  If this
+	 allocation fail we have no indication that the state_log array
+	 does not have the right size.  */
+      re_dfastate_t **new_array = re_realloc (mctx->state_log, re_dfastate_t *,
+					      pstr->bufs_len + 1);
+      if (BE (new_array == NULL, 0))
+	return REG_ESPACE;
+      mctx->state_log = new_array;
+    }
+
+  /* Then reconstruct the buffers.  */
+  if (pstr->icase)
+    {
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+	{
+	  ret = build_wcs_upper_buffer (pstr);
+	  if (BE (ret != REG_NOERROR, 0))
+	    return ret;
+	}
+      else
+#endif /* RE_ENABLE_I18N  */
+	build_upper_buffer (pstr);
+    }
+  else
+    {
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+	build_wcs_buffer (pstr);
+      else
+#endif /* RE_ENABLE_I18N  */
+	{
+	  if (pstr->trans != NULL)
+	    re_string_translate_buffer (pstr);
+	}
+    }
+  return REG_NOERROR;
+}
+
+
+/* Functions for matching context.  */
+
+/* Initialize MCTX.  */
+
+static reg_errcode_t
+internal_function
+match_ctx_init (re_match_context_t *mctx, int eflags, Idx n)
+{
+  mctx->eflags = eflags;
+  mctx->match_last = REG_MISSING;
+  if (n > 0)
+    {
+      /* Avoid overflow.  */
+      size_t max_object_size =
+	MAX (sizeof (struct re_backref_cache_entry),
+	     sizeof (re_sub_match_top_t *));
+      if (BE (SIZE_MAX / max_object_size < n, 0))
+	return REG_ESPACE;
+
+      mctx->bkref_ents = re_malloc (struct re_backref_cache_entry, n);
+      mctx->sub_tops = re_malloc (re_sub_match_top_t *, n);
+      if (BE (mctx->bkref_ents == NULL || mctx->sub_tops == NULL, 0))
+	return REG_ESPACE;
+    }
+  /* Already zero-ed by the caller.
+     else
+       mctx->bkref_ents = NULL;
+     mctx->nbkref_ents = 0;
+     mctx->nsub_tops = 0;  */
+  mctx->abkref_ents = n;
+  mctx->max_mb_elem_len = 1;
+  mctx->asub_tops = n;
+  return REG_NOERROR;
+}
+
+/* Clean the entries which depend on the current input in MCTX.
+   This function must be invoked when the matcher changes the start index
+   of the input, or changes the input string.  */
+
+static void
+internal_function
+match_ctx_clean (re_match_context_t *mctx)
+{
+  Idx st_idx;
+  for (st_idx = 0; st_idx < mctx->nsub_tops; ++st_idx)
+    {
+      Idx sl_idx;
+      re_sub_match_top_t *top = mctx->sub_tops[st_idx];
+      for (sl_idx = 0; sl_idx < top->nlasts; ++sl_idx)
+	{
+	  re_sub_match_last_t *last = top->lasts[sl_idx];
+	  re_free (last->path.array);
+	  re_free (last);
+	}
+      re_free (top->lasts);
+      if (top->path)
+	{
+	  re_free (top->path->array);
+	  re_free (top->path);
+	}
+      free (top);
+    }
+
+  mctx->nsub_tops = 0;
+  mctx->nbkref_ents = 0;
+}
+
+/* Free all the memory associated with MCTX.  */
+
+static void
+internal_function
+match_ctx_free (re_match_context_t *mctx)
+{
+  /* First, free all the memory associated with MCTX->SUB_TOPS.  */
+  match_ctx_clean (mctx);
+  re_free (mctx->sub_tops);
+  re_free (mctx->bkref_ents);
+}
+
+/* Add a new backreference entry to MCTX.
+   Note that we assume that caller never call this function with duplicate
+   entry, and call with STR_IDX which isn't smaller than any existing entry.
+*/
+
+static reg_errcode_t
+internal_function
+match_ctx_add_entry (re_match_context_t *mctx, Idx node, Idx str_idx, Idx from,
+		     Idx to)
+{
+  if (mctx->nbkref_ents >= mctx->abkref_ents)
+    {
+      struct re_backref_cache_entry* new_entry;
+      new_entry = re_realloc (mctx->bkref_ents, struct re_backref_cache_entry,
+			      mctx->abkref_ents * 2);
+      if (BE (new_entry == NULL, 0))
+	{
+	  re_free (mctx->bkref_ents);
+	  return REG_ESPACE;
+	}
+      mctx->bkref_ents = new_entry;
+      memset (mctx->bkref_ents + mctx->nbkref_ents, '\0',
+	      sizeof (struct re_backref_cache_entry) * mctx->abkref_ents);
+      mctx->abkref_ents *= 2;
+    }
+  if (mctx->nbkref_ents > 0
+      && mctx->bkref_ents[mctx->nbkref_ents - 1].str_idx == str_idx)
+    mctx->bkref_ents[mctx->nbkref_ents - 1].more = 1;
+
+  mctx->bkref_ents[mctx->nbkref_ents].node = node;
+  mctx->bkref_ents[mctx->nbkref_ents].str_idx = str_idx;
+  mctx->bkref_ents[mctx->nbkref_ents].subexp_from = from;
+  mctx->bkref_ents[mctx->nbkref_ents].subexp_to = to;
+
+  /* This is a cache that saves negative results of check_dst_limits_calc_pos.
+     If bit N is clear, means that this entry won't epsilon-transition to
+     an OP_OPEN_SUBEXP or OP_CLOSE_SUBEXP for the N+1-th subexpression.  If
+     it is set, check_dst_limits_calc_pos_1 will recurse and try to find one
+     such node.
+
+     A backreference does not epsilon-transition unless it is empty, so set
+     to all zeros if FROM != TO.  */
+  mctx->bkref_ents[mctx->nbkref_ents].eps_reachable_subexps_map
+    = (from == to ? -1 : 0);
+
+  mctx->bkref_ents[mctx->nbkref_ents++].more = 0;
+  if (mctx->max_mb_elem_len < to - from)
+    mctx->max_mb_elem_len = to - from;
+  return REG_NOERROR;
+}
+
+/* Return the first entry with the same str_idx, or REG_MISSING if none is
+   found.  Note that MCTX->BKREF_ENTS is already sorted by MCTX->STR_IDX.  */
+
+static Idx
+internal_function
+search_cur_bkref_entry (const re_match_context_t *mctx, Idx str_idx)
+{
+  Idx left, right, mid, last;
+  last = right = mctx->nbkref_ents;
+  for (left = 0; left < right;)
+    {
+      mid = (left + right) / 2;
+      if (mctx->bkref_ents[mid].str_idx < str_idx)
+	left = mid + 1;
+      else
+	right = mid;
+    }
+  if (left < last && mctx->bkref_ents[left].str_idx == str_idx)
+    return left;
+  else
+    return REG_MISSING;
+}
+
+/* Register the node NODE, whose type is OP_OPEN_SUBEXP, and which matches
+   at STR_IDX.  */
+
+static reg_errcode_t
+internal_function
+match_ctx_add_subtop (re_match_context_t *mctx, Idx node, Idx str_idx)
+{
+#ifdef DEBUG
+  assert (mctx->sub_tops != NULL);
+  assert (mctx->asub_tops > 0);
+#endif
+  if (BE (mctx->nsub_tops == mctx->asub_tops, 0))
+    {
+      Idx new_asub_tops = mctx->asub_tops * 2;
+      re_sub_match_top_t **new_array = re_realloc (mctx->sub_tops,
+						   re_sub_match_top_t *,
+						   new_asub_tops);
+      if (BE (new_array == NULL, 0))
+	return REG_ESPACE;
+      mctx->sub_tops = new_array;
+      mctx->asub_tops = new_asub_tops;
+    }
+  mctx->sub_tops[mctx->nsub_tops] = calloc (1, sizeof (re_sub_match_top_t));
+  if (BE (mctx->sub_tops[mctx->nsub_tops] == NULL, 0))
+    return REG_ESPACE;
+  mctx->sub_tops[mctx->nsub_tops]->node = node;
+  mctx->sub_tops[mctx->nsub_tops++]->str_idx = str_idx;
+  return REG_NOERROR;
+}
+
+/* Register the node NODE, whose type is OP_CLOSE_SUBEXP, and which matches
+   at STR_IDX, whose corresponding OP_OPEN_SUBEXP is SUB_TOP.  */
+
+static re_sub_match_last_t *
+internal_function
+match_ctx_add_sublast (re_sub_match_top_t *subtop, Idx node, Idx str_idx)
+{
+  re_sub_match_last_t *new_entry;
+  if (BE (subtop->nlasts == subtop->alasts, 0))
+    {
+      Idx new_alasts = 2 * subtop->alasts + 1;
+      re_sub_match_last_t **new_array = re_realloc (subtop->lasts,
+						    re_sub_match_last_t *,
+						    new_alasts);
+      if (BE (new_array == NULL, 0))
+	return NULL;
+      subtop->lasts = new_array;
+      subtop->alasts = new_alasts;
+    }
+  new_entry = calloc (1, sizeof (re_sub_match_last_t));
+  if (BE (new_entry != NULL, 1))
+    {
+      subtop->lasts[subtop->nlasts] = new_entry;
+      new_entry->node = node;
+      new_entry->str_idx = str_idx;
+      ++subtop->nlasts;
+    }
+  return new_entry;
+}
+
+static void
+internal_function
+sift_ctx_init (re_sift_context_t *sctx, re_dfastate_t **sifted_sts,
+	       re_dfastate_t **limited_sts, Idx last_node, Idx last_str_idx)
+{
+  sctx->sifted_states = sifted_sts;
+  sctx->limited_states = limited_sts;
+  sctx->last_node = last_node;
+  sctx->last_str_idx = last_str_idx;
+  re_node_set_init_empty (&sctx->limits);
+}
diff --git a/src/bin/m4/lib/sigprocmask.c b/src/bin/m4/lib/sigprocmask.c
new file mode 100644
index 0000000000..c38c7e32fd
--- /dev/null
+++ b/src/bin/m4/lib/sigprocmask.c
@@ -0,0 +1,192 @@
+/* POSIX compatible signal blocking.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "sigprocmask.h"
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/* We assume that a platform without POSIX signal blocking functions also
+   does not have the POSIX sigaction() function, only the signal() function.
+   This is true for Woe32 platforms.  */
+
+/* A signal handler.  */
+typedef void (*handler_t) (int signal);
+
+int
+sigismember (const sigset_t *set, int sig)
+{
+  if (sig >= 0 && sig < NSIG)
+    return (*set >> sig) & 1;
+  else
+    return 0;
+}
+
+int
+sigemptyset (sigset_t *set)
+{
+  *set = 0;
+  return 0;
+}
+
+int
+sigaddset (sigset_t *set, int sig)
+{
+  if (sig >= 0 && sig < NSIG)
+    {
+      *set |= 1U << sig;
+      return 0;
+    }
+  else
+    {
+      errno = EINVAL;
+      return -1;
+    }
+}
+
+int
+sigdelset (sigset_t *set, int sig)
+{
+  if (sig >= 0 && sig < NSIG)
+    {
+      *set &= ~(1U << sig);
+      return 0;
+    }
+  else
+    {
+      errno = EINVAL;
+      return -1;
+    }
+}
+
+int
+sigfillset (sigset_t *set)
+{
+  *set = (2U << (NSIG - 1)) - 1;
+  return 0;
+}
+
+/* Set of currently blocked signals.  */
+static sigset_t blocked_set /* = 0 */;
+
+/* Set of currently blocked and pending signals.  */
+static volatile sig_atomic_t pending_array[NSIG] /* = { 0 } */;
+
+/* Signal handler that is installed for blocked signals.  */
+static void
+blocked_handler (int sig)
+{
+  if (sig >= 0 && sig < NSIG)
+    pending_array[sig] = 1;
+}
+
+int
+sigpending (sigset_t *set)
+{
+  sigset_t pending = 0;
+  int sig;
+
+  for (sig = 0; sig < NSIG; sig++)
+    if (pending_array[sig])
+      pending |= 1U << sig;
+  return pending;
+}
+
+/* The previous signal handlers.
+   Only the array elements corresponding to blocked signals are relevant.  */
+static handler_t old_handlers[NSIG];
+
+int
+sigprocmask (int operation, const sigset_t *set, sigset_t *old_set)
+{
+  if (old_set != NULL)
+    *old_set = blocked_set;
+
+  if (set != NULL)
+    {
+      sigset_t new_blocked_set;
+      sigset_t to_unblock;
+      sigset_t to_block;
+
+      switch (operation)
+	{
+	case SIG_BLOCK:
+	  new_blocked_set = blocked_set | *set;
+	  break;
+	case SIG_SETMASK:
+	  new_blocked_set = *set;
+	  break;
+	case SIG_UNBLOCK:
+	  new_blocked_set = blocked_set & ~*set;
+	  break;
+	default:
+	  errno = EINVAL;
+	  return -1;
+	}
+      to_unblock = blocked_set & ~new_blocked_set;
+      to_block = new_blocked_set & ~blocked_set;
+
+      if (to_block != 0)
+	{
+	  int sig;
+
+	  for (sig = 0; sig < NSIG; sig++)
+	    if ((to_block >> sig) & 1)
+	      {
+		pending_array[sig] = 0;
+		if ((old_handlers[sig] = signal (sig, blocked_handler)) != SIG_ERR)
+		  blocked_set |= 1U << sig;
+	      }
+	}
+
+      if (to_unblock != 0)
+	{
+	  sig_atomic_t received[NSIG];
+	  int sig;
+
+	  for (sig = 0; sig < NSIG; sig++)
+	    if ((to_unblock >> sig) & 1)
+	      {
+		if (signal (sig, old_handlers[sig]) != blocked_handler)
+		  /* The application changed a signal handler while the signal
+		     was blocked.  We don't support this.  */
+		  abort ();
+		received[sig] = pending_array[sig];
+		blocked_set &= ~(1U << sig);
+		pending_array[sig] = 0;
+	      }
+	    else
+	      received[sig] = 0;
+
+	  for (sig = 0; sig < NSIG; sig++)
+	    if (received[sig])
+	      {
+		#if HAVE_RAISE
+		raise (sig);
+		#else
+		kill (getpid (), sig);
+		#endif
+	      }
+	}
+    }
+  return 0;
+}
diff --git a/src/bin/m4/lib/sigprocmask.h b/src/bin/m4/lib/sigprocmask.h
new file mode 100644
index 0000000000..d31c365a30
--- /dev/null
+++ b/src/bin/m4/lib/sigprocmask.h
@@ -0,0 +1,69 @@
+/* POSIX compatible signal blocking.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <signal.h>
+
+#if ! HAVE_POSIX_SIGNALBLOCKING
+
+/* Mingw defines sigset_t not in <signal.h>, but in <sys/types.h>.  */
+# include <sys/types.h>
+
+# include "verify.h"
+
+/* Maximum signal number + 1.  */
+# ifndef NSIG
+#  define NSIG 32
+# endif
+
+/* This code supports only 32 signals.  */
+verify (NSIG <= 32);
+
+/* A set or mask of signals.  */
+# if !HAVE_SIGSET_T
+typedef unsigned int sigset_t;
+# endif
+
+/* Test whether a given signal is contained in a signal set.  */
+extern int sigismember (const sigset_t *set, int sig);
+
+/* Initialize a signal set to the empty set.  */
+extern int sigemptyset (sigset_t *set);
+
+/* Add a signal to a signal set.  */
+extern int sigaddset (sigset_t *set, int sig);
+
+/* Remove a signal from a signal set.  */
+extern int sigdelset (sigset_t *set, int sig);
+
+/* Fill a signal set with all possible signals.  */
+extern int sigfillset (sigset_t *set);
+
+/* Return the set of those blocked signals that are pending.  */
+extern int sigpending (sigset_t *set);
+
+/* If OLD_SET is not NULL, put the current set of blocked signals in *OLD_SET.
+   Then, if SET is not NULL, affect the current set of blocked signals by
+   combining it with *SET as indicated in OPERATION.
+   In this implementation, you are not allowed to change a signal handler
+   while the signal is blocked.  */
+# define SIG_BLOCK   0  /* blocked_set = blocked_set | *set; */
+# define SIG_SETMASK 1  /* blocked_set = *set; */
+# define SIG_UNBLOCK 2  /* blocked_set = blocked_set & ~*set; */
+extern int sigprocmask (int operation, const sigset_t *set, sigset_t *old_set);
+
+#endif
diff --git a/src/bin/m4/lib/size_max.h b/src/bin/m4/lib/size_max.h
new file mode 100644
index 0000000000..ed0bc13771
--- /dev/null
+++ b/src/bin/m4/lib/size_max.h
@@ -0,0 +1,31 @@
+/* size_max.h -- declare SIZE_MAX through system headers
+   Copyright (C) 2005-2006 Free Software Foundation, Inc.
+   Written by Simon Josefsson.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef GNULIB_SIZE_MAX_H
+#define GNULIB_SIZE_MAX_H
+
+/* Get SIZE_MAX declaration on systems like Solaris 7/8/9.  */
+# include <limits.h>
+/* Get SIZE_MAX declaration on systems like glibc 2.  */
+# if HAVE_STDINT_H
+#  include <stdint.h>
+# endif
+/* On systems where these include files don't define it, SIZE_MAX is defined
+   in config.h.  */
+
+#endif /* GNULIB_SIZE_MAX_H */
diff --git a/src/bin/m4/lib/stat_.h b/src/bin/m4/lib/stat_.h
new file mode 100644
index 0000000000..cbf5ac00ac
--- /dev/null
+++ b/src/bin/m4/lib/stat_.h
@@ -0,0 +1,275 @@
+/* Provide a more complete sys/stat header file.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Eric Blake, Paul Eggert, and Jim Meyering.  */
+
+#ifndef _gl_SYS_STAT_H
+#define _gl_SYS_STAT_H
+
+/* This file is supposed to be used on platforms where <sys/stat.h> is
+   incomplete.  It is intended to provide definitions and prototypes
+   needed by an application.  Start with what the system provides.  */
+#include @ABSOLUTE_SYS_STAT_H@
+
+#ifndef S_IFMT
+# define S_IFMT 0170000
+#endif
+
+#if STAT_MACROS_BROKEN
+# undef S_ISBLK
+# undef S_ISCHR
+# undef S_ISDIR
+# undef S_ISFIFO
+# undef S_ISLNK
+# undef S_ISNAM
+# undef S_ISMPB
+# undef S_ISMPC
+# undef S_ISNWK
+# undef S_ISREG
+# undef S_ISSOCK
+#endif
+
+#ifndef S_ISBLK
+# ifdef S_IFBLK
+#  define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
+# else
+#  define S_ISBLK(m) 0
+# endif
+#endif
+
+#ifndef S_ISCHR
+# ifdef S_IFCHR
+#  define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
+# else
+#  define S_ISCHR(m) 0
+# endif
+#endif
+
+#ifndef S_ISDIR
+# ifdef S_IFDIR
+#  define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+# else
+#  define S_ISDIR(m) 0
+# endif
+#endif
+
+#ifndef S_ISDOOR /* Solaris 2.5 and up */
+# define S_ISDOOR(m) 0
+#endif
+
+#ifndef S_ISFIFO
+# ifdef S_IFIFO
+#  define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
+# else
+#  define S_ISFIFO(m) 0
+# endif
+#endif
+
+#ifndef S_ISLNK
+# ifdef S_IFLNK
+#  define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
+# else
+#  define S_ISLNK(m) 0
+# endif
+#endif
+
+#ifndef S_ISMPB /* V7 */
+# ifdef S_IFMPB
+#  define S_ISMPB(m) (((m) & S_IFMT) == S_IFMPB)
+#  define S_ISMPC(m) (((m) & S_IFMT) == S_IFMPC)
+# else
+#  define S_ISMPB(m) 0
+#  define S_ISMPC(m) 0
+# endif
+#endif
+
+#ifndef S_ISNAM /* Xenix */
+# ifdef S_IFNAM
+#  define S_ISNAM(m) (((m) & S_IFMT) == S_IFNAM)
+# else
+#  define S_ISNAM(m) 0
+# endif
+#endif
+
+#ifndef S_ISNWK /* HP/UX */
+# ifdef S_IFNWK
+#  define S_ISNWK(m) (((m) & S_IFMT) == S_IFNWK)
+# else
+#  define S_ISNWK(m) 0
+# endif
+#endif
+
+#ifndef S_ISPORT /* Solaris 10 and up */
+# define S_ISPORT(m) 0
+#endif
+
+#ifndef S_ISREG
+# ifdef S_IFREG
+#  define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
+# else
+#  define S_ISREG(m) 0
+# endif
+#endif
+
+#ifndef S_ISSOCK
+# ifdef S_IFSOCK
+#  define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
+# else
+#  define S_ISSOCK(m) 0
+# endif
+#endif
+
+
+#ifndef S_TYPEISMQ
+# define S_TYPEISMQ(p) 0
+#endif
+
+#ifndef S_TYPEISTMO
+# define S_TYPEISTMO(p) 0
+#endif
+
+
+#ifndef S_TYPEISSEM
+# ifdef S_INSEM
+#  define S_TYPEISSEM(p) (S_ISNAM ((p)->st_mode) && (p)->st_rdev == S_INSEM)
+# else
+#  define S_TYPEISSEM(p) 0
+# endif
+#endif
+
+#ifndef S_TYPEISSHM
+# ifdef S_INSHD
+#  define S_TYPEISSHM(p) (S_ISNAM ((p)->st_mode) && (p)->st_rdev == S_INSHD)
+# else
+#  define S_TYPEISSHM(p) 0
+# endif
+#endif
+
+/* high performance ("contiguous data") */
+#ifndef S_ISCTG
+# define S_ISCTG(p) 0
+#endif
+
+/* Cray DMF (data migration facility): off line, with data  */
+#ifndef S_ISOFD
+# define S_ISOFD(p) 0
+#endif
+
+/* Cray DMF (data migration facility): off line, with no data  */
+#ifndef S_ISOFL
+# define S_ISOFL(p) 0
+#endif
+
+/* 4.4BSD whiteout */
+#ifndef S_ISWHT
+# define S_ISWHT(m) 0
+#endif
+
+/* If any of the following are undefined,
+   define them to their de facto standard values.  */
+#if !S_ISUID
+# define S_ISUID 04000
+#endif
+#if !S_ISGID
+# define S_ISGID 02000
+#endif
+
+/* S_ISVTX is a common extension to POSIX.  */
+#ifndef S_ISVTX
+# define S_ISVTX 01000
+#endif
+
+#if !S_IRUSR && S_IREAD
+# define S_IRUSR S_IREAD
+#endif
+#if !S_IRUSR
+# define S_IRUSR 00400
+#endif
+#if !S_IRGRP
+# define S_IRGRP (S_IRUSR >> 3)
+#endif
+#if !S_IROTH
+# define S_IROTH (S_IRUSR >> 6)
+#endif
+
+#if !S_IWUSR && S_IWRITE
+# define S_IWUSR S_IWRITE
+#endif
+#if !S_IWUSR
+# define S_IWUSR 00200
+#endif
+#if !S_IWGRP
+# define S_IWGRP (S_IWUSR >> 3)
+#endif
+#if !S_IWOTH
+# define S_IWOTH (S_IWUSR >> 6)
+#endif
+
+#if !S_IXUSR && S_IEXEC
+# define S_IXUSR S_IEXEC
+#endif
+#if !S_IXUSR
+# define S_IXUSR 00100
+#endif
+#if !S_IXGRP
+# define S_IXGRP (S_IXUSR >> 3)
+#endif
+#if !S_IXOTH
+# define S_IXOTH (S_IXUSR >> 6)
+#endif
+
+#if !S_IRWXU
+# define S_IRWXU (S_IRUSR | S_IWUSR | S_IXUSR)
+#endif
+#if !S_IRWXG
+# define S_IRWXG (S_IRGRP | S_IWGRP | S_IXGRP)
+#endif
+#if !S_IRWXO
+# define S_IRWXO (S_IROTH | S_IWOTH | S_IXOTH)
+#endif
+
+/* S_IXUGO is a common extension to POSIX.  */
+#if !S_IXUGO
+# define S_IXUGO (S_IXUSR | S_IXGRP | S_IXOTH)
+#endif
+
+#ifndef S_IRWXUGO
+# define S_IRWXUGO (S_IRWXU | S_IRWXG | S_IRWXO)
+#endif
+
+/* mingw does not support symlinks, therefore it does not have lstat.  But
+   without links, stat does just fine.  */
+#if ! HAVE_LSTAT
+# define lstat stat
+#endif
+
+/* mingw's _mkdir() function has 1 argument, but we pass 2 arguments.
+   Additionally, it declares _mkdir (and depending on compile flags, an
+   alias mkdir), only in the nonstandard io.h.  */
+#if ! HAVE_DECL_MKDIR && HAVE_IO_H
+# include <io.h>
+
+static inline int
+rpl_mkdir (char const *name, mode_t mode)
+{
+  return _mkdir (name);
+}
+
+# define mkdir rpl_mkdir
+#endif
+
+#endif /* _gl_SYS_STAT_H */
diff --git a/src/bin/m4/lib/stdbool_.h b/src/bin/m4/lib/stdbool_.h
new file mode 100644
index 0000000000..efa80ba921
--- /dev/null
+++ b/src/bin/m4/lib/stdbool_.h
@@ -0,0 +1,115 @@
+/* Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _STDBOOL_H
+#define _STDBOOL_H
+
+/* ISO C 99 <stdbool.h> for platforms that lack it.  */
+
+/* Usage suggestions:
+
+   Programs that use <stdbool.h> should be aware of some limitations
+   and standards compliance issues.
+
+   Standards compliance:
+
+       - <stdbool.h> must be #included before 'bool', 'false', 'true'
+         can be used.
+
+       - You cannot assume that sizeof (bool) == 1.
+
+       - Programs should not undefine the macros bool, true, and false,
+         as C99 lists that as an "obsolescent feature".
+
+   Limitations of this substitute, when used in a C89 environment:
+
+       - <stdbool.h> must be #included before the '_Bool' type can be used.
+
+       - You cannot assume that _Bool is a typedef; it might be a macro.
+
+       - In C99, casts and automatic conversions to '_Bool' or 'bool' are
+         performed in such a way that every nonzero value gets converted
+         to 'true', and zero gets converted to 'false'.  This doesn't work
+         with this substitute.  With this substitute, only the values 0 and 1
+         give the expected result when converted to _Bool' or 'bool'.
+
+   Also, it is suggested that programs use 'bool' rather than '_Bool';
+   this isn't required, but 'bool' is more common.  */
+
+
+/* 7.16. Boolean type and values */
+
+/* BeOS <sys/socket.h> already #defines false 0, true 1.  We use the same
+   definitions below, but temporarily we have to #undef them.  */
+#ifdef __BEOS__
+# include <OS.h> /* defines bool but not _Bool */
+# undef false
+# undef true
+#endif
+
+/* For the sake of symbolic names in gdb, we define true and false as
+   enum constants, not only as macros.
+   It is tempting to write
+      typedef enum { false = 0, true = 1 } _Bool;
+   so that gdb prints values of type 'bool' symbolically. But if we do
+   this, values of type '_Bool' may promote to 'int' or 'unsigned int'
+   (see ISO C 99 6.7.2.2.(4)); however, '_Bool' must promote to 'int'
+   (see ISO C 99 6.3.1.1.(2)).  So we add a negative value to the
+   enum; this ensures that '_Bool' promotes to 'int'.  */
+#if defined __cplusplus || defined __BEOS__
+  /* A compiler known to have 'bool'.  */
+  /* If the compiler already has both 'bool' and '_Bool', we can assume they
+     are the same types.  */
+# if !@HAVE__BOOL@
+typedef bool _Bool;
+# endif
+#else
+# if !defined __GNUC__
+   /* If @HAVE__BOOL@:
+        Some HP-UX cc and AIX IBM C compiler versions have compiler bugs when
+        the built-in _Bool type is used.  See
+          http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
+          http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
+          http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html
+        Similar bugs are likely with other compilers as well; this file
+        wouldn't be used if <stdbool.h> was working.
+        So we override the _Bool type.
+      If !@HAVE__BOOL@:
+        Need to define _Bool ourselves. As 'signed char' or as an enum type?
+        Use of a typedef, with SunPRO C, leads to a stupid
+          "warning: _Bool is a keyword in ISO C99".
+        Use of an enum type, with IRIX cc, leads to a stupid
+          "warning(1185): enumerated type mixed with another type".
+        The only benefit of the enum type, debuggability, is not important
+        with these compilers.  So use 'signed char' and no typedef.  */
+#  define _Bool signed char
+enum { false = 0, true = 1 };
+# else
+   /* With this compiler, trust the _Bool type if the compiler has it.  */
+#  if !@HAVE__BOOL@
+typedef enum { _Bool_must_promote_to_int = -1, false = 0, true = 1 } _Bool;
+#  endif
+# endif
+#endif
+#define bool _Bool
+
+/* The other macros must be usable in preprocessor directives.  */
+#define false 0
+#define true 1
+#define __bool_true_false_are_defined 1
+
+#endif /* _STDBOOL_H */
diff --git a/src/bin/m4/lib/stdint_.h b/src/bin/m4/lib/stdint_.h
new file mode 100644
index 0000000000..a4f9a4cf7b
--- /dev/null
+++ b/src/bin/m4/lib/stdint_.h
@@ -0,0 +1,493 @@
+/* Copyright (C) 2001-2002, 2004-2006 Free Software Foundation, Inc.
+   Written by Paul Eggert, Bruno Haible, Sam Steingold, Peter Burwood.
+   This file is part of gnulib.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GL_STDINT_H
+#define _GL_STDINT_H
+
+/*
+ * ISO C 99 <stdint.h> for platforms that lack it.
+ * <http://www.opengroup.org/susv3xbd/stdint.h.html>
+ */
+
+/* Get those types that are already defined in other system include
+   files, so that we can "#define int8_t signed char" below without
+   worrying about a later system include file containing a "typedef
+   signed char int8_t;" that will get messed up by our macro.  Our
+   macros should all be consistent with the system versions, except
+   for the "fast" types and macros, which we recommend against using
+   in public interfaces due to compiler differences.  */
+
+#if @HAVE_STDINT_H@
+# if defined __sgi && ! defined __c99
+   /* Bypass IRIX's <stdint.h> if in C89 mode, since it merely annoys users
+      with "This header file is to be used only for c99 mode compilations"
+      diagnostics.  */
+#  define __STDINT_H__
+# endif
+  /* Other systems may have an incomplete or buggy <stdint.h>.
+     Include it before <inttypes.h>, since any "#include <stdint.h>"
+     in <inttypes.h> would reinclude us, skipping our contents because
+     _GL_STDINT_H is defined.  */
+# include @ABSOLUTE_STDINT_H@
+#endif
+
+/* <sys/types.h> defines some of the stdint.h types as well, on glibc,
+   IRIX 6.5, and OpenBSD 3.8 (via <machine/types.h>).
+   AIX 5.2 <sys/types.h> isn't needed and causes troubles.
+   MacOS X 10.4.6 <sys/types.h> includes <stdint.h> (which is us), but
+   relies on the system <stdint.h> definitions, so include
+   <sys/types.h> after @ABSOLUTE_STDINT_H@.  */
+#if @HAVE_SYS_TYPES_H@ && ! defined _AIX
+# include <sys/types.h>
+#endif
+
+/* Get LONG_MIN, LONG_MAX, ULONG_MAX.  */
+#include <limits.h>
+
+#if @HAVE_INTTYPES_H@
+  /* In OpenBSD 3.8, <inttypes.h> includes <machine/types.h>, which defines
+     int{8,16,32,64}_t, uint{8,16,32,64}_t and __BIT_TYPES_DEFINED__.
+     <inttypes.h> also defines intptr_t and uintptr_t.  */
+# define _GL_JUST_INCLUDE_ABSOLUTE_INTTYPES_H
+# include <inttypes.h>
+# undef _GL_JUST_INCLUDE_ABSOLUTE_INTTYPES_H
+#elif @HAVE_SYS_INTTYPES_H@
+  /* Solaris 7 <sys/inttypes.h> has the types except the *_fast*_t types, and
+     the macros except for *_FAST*_*, INTPTR_MIN, PTRDIFF_MIN, PTRDIFF_MAX.  */
+# include <sys/inttypes.h>
+#endif
+
+#if @HAVE_SYS_BITYPES_H@ && ! defined __BIT_TYPES_DEFINED__
+  /* Linux libc4 >= 4.6.7 and libc5 have a <sys/bitypes.h> that defines
+     int{8,16,32,64}_t and __BIT_TYPES_DEFINED__.  In libc5 >= 5.2.2 it is
+     included by <sys/types.h>.  */
+# include <sys/bitypes.h>
+#endif
+
+#if ! defined __cplusplus || defined __STDC_CONSTANT_MACROS
+
+/* Get WCHAR_MIN, WCHAR_MAX.  */
+# if @HAVE_WCHAR_H@ && ! (defined WCHAR_MIN && defined WCHAR_MAX)
+   /* BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
+      <wchar.h>.  */
+#  include <stdio.h>
+#  include <time.h>
+#  include <wchar.h>
+# endif
+
+#endif
+
+/* Minimum and maximum values for a integer type under the usual assumption.
+   Return an unspecified value if BITS == 0, adding a check to pacify
+   picky compilers.  */
+
+#define _STDINT_MIN(signed, bits, zero) \
+  ((signed) ? (- ((zero) + 1) << ((bits) ? (bits) - 1 : 0)) : (zero))
+
+#define _STDINT_MAX(signed, bits, zero) \
+  ((signed) \
+   ? ~ _STDINT_MIN (signed, bits, zero) \
+   : ((((zero) + 1) << ((bits) ? (bits) - 1 : 0)) - 1) * 2 + 1)
+
+/* 7.18.1.1. Exact-width integer types */
+
+/* Here we assume a standard architecture where the hardware integer
+   types have 8, 16, 32, optionally 64 bits.  */
+
+#undef int8_t
+#undef uint8_t
+#define int8_t signed char
+#define uint8_t unsigned char
+
+#undef int16_t
+#undef uint16_t
+#define int16_t short int
+#define uint16_t unsigned short int
+
+#undef int32_t
+#undef uint32_t
+#define int32_t int
+#define uint32_t unsigned int
+
+#undef int64_t
+#if LONG_MAX >> 31 >> 31 == 1
+# define int64_t long int
+#elif defined _MSC_VER
+# define int64_t __int64
+#elif @HAVE_LONG_LONG_INT@
+# define int64_t long long int
+#endif
+
+#undef uint64_t
+#if ULONG_MAX >> 31 >> 31 >> 1 == 1
+# define uint64_t unsigned long int
+#elif defined _MSC_VER
+# define uint64_t unsigned __int64
+#elif @HAVE_UNSIGNED_LONG_LONG_INT@
+# define uint64_t unsigned long long int
+#endif
+
+/* Avoid collision with Solaris 2.5.1 <pthread.h> etc.  */
+#define _UINT8_T
+#define _UINT32_T
+#define _UINT64_T
+
+
+/* 7.18.1.2. Minimum-width integer types */
+
+/* Here we assume a standard architecture where the hardware integer
+   types have 8, 16, 32, optionally 64 bits. Therefore the leastN_t types
+   are the same as the corresponding N_t types.  */
+
+#undef int_least8_t
+#undef uint_least8_t
+#undef int_least16_t
+#undef uint_least16_t
+#undef int_least32_t
+#undef uint_least32_t
+#undef int_least64_t
+#undef uint_least64_t
+#define int_least8_t int8_t
+#define uint_least8_t uint8_t
+#define int_least16_t int16_t
+#define uint_least16_t uint16_t
+#define int_least32_t int32_t
+#define uint_least32_t uint32_t
+#ifdef int64_t
+# define int_least64_t int64_t
+#endif
+#ifdef uint64_t
+# define uint_least64_t uint64_t
+#endif
+
+/* 7.18.1.3. Fastest minimum-width integer types */
+
+/* Note: Other <stdint.h> substitutes may define these types differently.
+   It is not recommended to use these types in public header files. */
+
+/* Here we assume a standard architecture where the hardware integer
+   types have 8, 16, 32, optionally 64 bits. Therefore the fastN_t types
+   are taken from the same list of types.  Assume that 'long int'
+   is fast enough for all narrower integers.  */
+
+#undef int_fast8_t
+#undef uint_fast8_t
+#undef int_fast16_t
+#undef uint_fast16_t
+#undef int_fast32_t
+#undef uint_fast32_t
+#undef int_fast64_t
+#undef uint_fast64_t
+#define int_fast8_t long int
+#define uint_fast8_t unsigned int_fast8_t
+#define int_fast16_t long int
+#define uint_fast16_t unsigned int_fast16_t
+#define int_fast32_t long int
+#define uint_fast32_t unsigned int_fast32_t
+#ifdef int64_t
+# define int_fast64_t int64_t
+#endif
+#ifdef uint64_t
+# define uint_fast64_t uint64_t
+#endif
+
+/* 7.18.1.4. Integer types capable of holding object pointers */
+
+#undef intptr_t
+#undef uintptr_t
+#define intptr_t long int
+#define uintptr_t unsigned long int
+
+/* 7.18.1.5. Greatest-width integer types */
+
+/* Note: These types are compiler dependent. It may be unwise to use them in
+   public header files. */
+
+#undef intmax_t
+#if @HAVE_LONG_LONG_INT@ && LONG_MAX >> 30 == 1
+# define intmax_t long long int
+#elif defined int64_t
+# define intmax_t int64_t
+#else
+# define intmax_t long int
+#endif
+
+#undef uintmax_t
+#if @HAVE_UNSIGNED_LONG_LONG_INT@ && ULONG_MAX >> 31 == 1
+# define uintmax_t unsigned long long int
+#elif defined uint64_t
+# define uintmax_t uint64_t
+#else
+# define uintmax_t unsigned long int
+#endif
+
+/* 7.18.2. Limits of specified-width integer types */
+
+#if ! defined __cplusplus || defined __STDC_LIMIT_MACROS
+
+/* 7.18.2.1. Limits of exact-width integer types */
+
+/* Here we assume a standard architecture where the hardware integer
+   types have 8, 16, 32, optionally 64 bits.  */
+
+#undef INT8_MIN
+#undef INT8_MAX
+#undef UINT8_MAX
+#define INT8_MIN  (~ INT8_MAX)
+#define INT8_MAX  127
+#define UINT8_MAX  255
+
+#undef INT16_MIN
+#undef INT16_MAX
+#undef UINT16_MAX
+#define INT16_MIN  (~ INT16_MAX)
+#define INT16_MAX  32767
+#define UINT16_MAX  65535
+
+#undef INT32_MIN
+#undef INT32_MAX
+#undef UINT32_MAX
+#define INT32_MIN  (~ INT32_MAX)
+#define INT32_MAX  2147483647
+#define UINT32_MAX  4294967295U
+
+#undef INT64_MIN
+#undef INT64_MAX
+#ifdef int64_t
+# define INT64_MIN  (~ INT64_MAX)
+# define INT64_MAX  INTMAX_C (9223372036854775807)
+#endif
+
+#undef UINT64_MAX
+#ifdef uint64_t
+# define UINT64_MAX  UINTMAX_C (18446744073709551615)
+#endif
+
+/* 7.18.2.2. Limits of minimum-width integer types */
+
+/* Here we assume a standard architecture where the hardware integer
+   types have 8, 16, 32, optionally 64 bits. Therefore the leastN_t types
+   are the same as the corresponding N_t types.  */
+
+#undef INT_LEAST8_MIN
+#undef INT_LEAST8_MAX
+#undef UINT_LEAST8_MAX
+#define INT_LEAST8_MIN  INT8_MIN
+#define INT_LEAST8_MAX  INT8_MAX
+#define UINT_LEAST8_MAX  UINT8_MAX
+
+#undef INT_LEAST16_MIN
+#undef INT_LEAST16_MAX
+#undef UINT_LEAST16_MAX
+#define INT_LEAST16_MIN  INT16_MIN
+#define INT_LEAST16_MAX  INT16_MAX
+#define UINT_LEAST16_MAX  UINT16_MAX
+
+#undef INT_LEAST32_MIN
+#undef INT_LEAST32_MAX
+#undef UINT_LEAST32_MAX
+#define INT_LEAST32_MIN  INT32_MIN
+#define INT_LEAST32_MAX  INT32_MAX
+#define UINT_LEAST32_MAX  UINT32_MAX
+
+#undef INT_LEAST64_MIN
+#undef INT_LEAST64_MAX
+#ifdef int64_t
+# define INT_LEAST64_MIN  INT64_MIN
+# define INT_LEAST64_MAX  INT64_MAX
+#endif
+
+#undef UINT_LEAST64_MAX
+#ifdef uint64_t
+# define UINT_LEAST64_MAX  UINT64_MAX
+#endif
+
+/* 7.18.2.3. Limits of fastest minimum-width integer types */
+
+/* Here we assume a standard architecture where the hardware integer
+   types have 8, 16, 32, optionally 64 bits. Therefore the fastN_t types
+   are taken from the same list of types.  */
+
+#undef INT_FAST8_MIN
+#undef INT_FAST8_MAX
+#undef UINT_FAST8_MAX
+#define INT_FAST8_MIN  LONG_MIN
+#define INT_FAST8_MAX  LONG_MAX
+#define UINT_FAST8_MAX  ULONG_MAX
+
+#undef INT_FAST16_MIN
+#undef INT_FAST16_MAX
+#undef UINT_FAST16_MAX
+#define INT_FAST16_MIN  LONG_MIN
+#define INT_FAST16_MAX  LONG_MAX
+#define UINT_FAST16_MAX  ULONG_MAX
+
+#undef INT_FAST32_MIN
+#undef INT_FAST32_MAX
+#undef UINT_FAST32_MAX
+#define INT_FAST32_MIN  LONG_MIN
+#define INT_FAST32_MAX  LONG_MAX
+#define UINT_FAST32_MAX  ULONG_MAX
+
+#undef INT_FAST64_MIN
+#undef INT_FAST64_MAX
+#ifdef int64_t
+# define INT_FAST64_MIN  INT64_MIN
+# define INT_FAST64_MAX  INT64_MAX
+#endif
+
+#undef UINT_FAST64_MAX
+#ifdef uint64_t
+# define UINT_FAST64_MAX  UINT64_MAX
+#endif
+
+/* 7.18.2.4. Limits of integer types capable of holding object pointers */
+
+#undef INTPTR_MIN
+#undef INTPTR_MAX
+#undef UINTPTR_MAX
+#define INTPTR_MIN  LONG_MIN
+#define INTPTR_MAX  LONG_MAX
+#define UINTPTR_MAX  ULONG_MAX
+
+/* 7.18.2.5. Limits of greatest-width integer types */
+
+#undef INTMAX_MIN
+#undef INTMAX_MAX
+#define INTMAX_MIN  (~ INTMAX_MAX)
+#ifdef INT64_MAX
+# define INTMAX_MAX  INT64_MAX
+#else
+# define INTMAX_MAX  INT32_MAX
+#endif
+
+#undef UINTMAX_MAX
+#ifdef UINT64_MAX
+# define UINTMAX_MAX  UINT64_MAX
+#else
+# define UINTMAX_MAX  UINT32_MAX
+#endif
+
+/* 7.18.3. Limits of other integer types */
+
+/* ptrdiff_t limits */
+#undef PTRDIFF_MIN
+#undef PTRDIFF_MAX
+#define PTRDIFF_MIN  \
+   _STDINT_MIN (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
+#define PTRDIFF_MAX  \
+   _STDINT_MAX (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
+
+/* sig_atomic_t limits */
+#undef SIG_ATOMIC_MIN
+#undef SIG_ATOMIC_MAX
+#define SIG_ATOMIC_MIN  \
+   _STDINT_MIN (@HAVE_SIGNED_SIG_ATOMIC_T@, @BITSIZEOF_SIG_ATOMIC_T@, \
+		0@SIG_ATOMIC_T_SUFFIX@)
+#define SIG_ATOMIC_MAX  \
+   _STDINT_MAX (@HAVE_SIGNED_SIG_ATOMIC_T@, @BITSIZEOF_SIG_ATOMIC_T@, \
+		0@SIG_ATOMIC_T_SUFFIX@)
+
+
+/* size_t limit */
+#undef SIZE_MAX
+#define SIZE_MAX  _STDINT_MAX (0, @BITSIZEOF_SIZE_T@, 0@SIZE_T_SUFFIX@)
+
+/* wchar_t limits */
+#undef WCHAR_MIN
+#undef WCHAR_MAX
+#define WCHAR_MIN  \
+   _STDINT_MIN (@HAVE_SIGNED_WCHAR_T@, @BITSIZEOF_WCHAR_T@, 0@WCHAR_T_SUFFIX@)
+#define WCHAR_MAX  \
+   _STDINT_MAX (@HAVE_SIGNED_WCHAR_T@, @BITSIZEOF_WCHAR_T@, 0@WCHAR_T_SUFFIX@)
+
+/* wint_t limits */
+#undef WINT_MIN
+#undef WINT_MAX
+#define WINT_MIN  \
+   _STDINT_MIN (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, 0@WINT_T_SUFFIX@)
+#define WINT_MAX  \
+   _STDINT_MAX (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, 0@WINT_T_SUFFIX@)
+
+#endif /* !defined __cplusplus || defined __STDC_LIMIT_MACROS */
+
+/* 7.18.4. Macros for integer constants */
+
+#if ! defined __cplusplus || defined __STDC_CONSTANT_MACROS
+
+/* 7.18.4.1. Macros for minimum-width integer constants */
+/* According to ISO C 99 Technical Corrigendum 1 */
+
+/* Here we assume a standard architecture where the hardware integer
+   types have 8, 16, 32, optionally 64 bits, and int is 32 bits.  */
+
+#undef INT8_C
+#undef UINT8_C
+#define INT8_C(x) x
+#define UINT8_C(x) x
+
+#undef INT16_C
+#undef UINT16_C
+#define INT16_C(x) x
+#define UINT16_C(x) x
+
+#undef INT32_C
+#undef UINT32_C
+#define INT32_C(x) x
+#define UINT32_C(x) x ## U
+
+#undef INT64_C
+#undef UINT64_C
+#if LONG_MAX >> 31 >> 31 == 1
+# define INT64_C(x) x##L
+#elif defined _MSC_VER
+# define INT64_C(x) x##i64
+#elif @HAVE_LONG_LONG_INT@
+# define INT64_C(x) x##LL
+#endif
+#if ULONG_MAX >> 31 >> 31 >> 1 == 1
+# define UINT64_C(x) x##UL
+#elif defined _MSC_VER
+# define UINT64_C(x) x##ui64
+#elif @HAVE_UNSIGNED_LONG_LONG_INT@
+# define UINT64_C(x) x##ULL
+#endif
+
+/* 7.18.4.2. Macros for greatest-width integer constants */
+
+#undef INTMAX_C
+#if @HAVE_LONG_LONG_INT@ && LONG_MAX >> 30 == 1
+# define INTMAX_C(x)   x##LL
+#elif defined int64_t
+# define INTMAX_C(x)   INT64_C(x)
+#else
+# define INTMAX_C(x)   x##L
+#endif
+
+#undef UINTMAX_C
+#if @HAVE_UNSIGNED_LONG_LONG_INT@ && ULONG_MAX >> 31 == 1
+# define UINTMAX_C(x)  x##ULL
+#elif defined uint64_t
+# define UINTMAX_C(x)  UINT64_C(x)
+#else
+# define UINTMAX_C(x)  x##UL
+#endif
+
+#endif /* !defined __cplusplus || defined __STDC_CONSTANT_MACROS */
+
+#endif /* _GL_STDINT_H */
diff --git a/src/bin/m4/lib/stdio--.h b/src/bin/m4/lib/stdio--.h
new file mode 100644
index 0000000000..2385e626ff
--- /dev/null
+++ b/src/bin/m4/lib/stdio--.h
@@ -0,0 +1,28 @@
+/* Like stdio.h, but redefine some names to avoid glitches.
+
+   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <stdio.h>
+#include "stdio-safer.h"
+
+#undef fopen
+#define fopen fopen_safer
+
+#undef tmpfile
+#define tmpfile tmpfile_safer
diff --git a/src/bin/m4/lib/stdio-safer.h b/src/bin/m4/lib/stdio-safer.h
new file mode 100644
index 0000000000..8329a1a093
--- /dev/null
+++ b/src/bin/m4/lib/stdio-safer.h
@@ -0,0 +1,24 @@
+/* Invoke stdio functions, but avoid some glitches.
+
+   Copyright (C) 2001, 2003, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <stdio.h>
+
+FILE *fopen_safer (char const *, char const *);
+FILE *tmpfile_safer (void);
diff --git a/src/bin/m4/lib/stdlib--.h b/src/bin/m4/lib/stdlib--.h
new file mode 100644
index 0000000000..b43b3dae6d
--- /dev/null
+++ b/src/bin/m4/lib/stdlib--.h
@@ -0,0 +1,26 @@
+/* Like stdlib.h, but redefine some names to avoid glitches.
+
+   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <stdlib.h>
+#include "stdlib-safer.h"
+
+#include "mkstemp.h"
+#undef mkstemp
+#define mkstemp mkstemp_safer
diff --git a/src/bin/m4/lib/stdlib-safer.h b/src/bin/m4/lib/stdlib-safer.h
new file mode 100644
index 0000000000..8b1a7e11e5
--- /dev/null
+++ b/src/bin/m4/lib/stdlib-safer.h
@@ -0,0 +1,21 @@
+/* Invoke stdlib.h functions, but avoid some glitches.
+
+   Copyright (C) 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+int mkstemp_safer (char *);
diff --git a/src/bin/m4/lib/strcase.h b/src/bin/m4/lib/strcase.h
new file mode 100644
index 0000000000..07d4c9a42b
--- /dev/null
+++ b/src/bin/m4/lib/strcase.h
@@ -0,0 +1,56 @@
+/* Case-insensitive string comparison functions.
+   Copyright (C) 1995-1996, 2001, 2003, 2005-2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _STRCASE_H
+#define _STRCASE_H
+
+#include <stddef.h>
+/* Include header files with a possibly conflicting declarations of strcasecmp
+   before we define it as a macro, so that they will be no-ops if included
+   after strcasecmp is defined as a macro.  */
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* No known system has a strcasecmp() function that works correctly in
+   multibyte locales.  Therefore we use our version always.  */
+#define strcasecmp rpl_strcasecmp
+/* Compare strings S1 and S2, ignoring case, returning less than, equal to or
+   greater than zero if S1 is lexicographically less than, equal to or greater
+   than S2.
+   Note: This function may, in multibyte locales, return 0 for strings of
+   different lengths!  */
+extern int strcasecmp (const char *s1, const char *s2);
+
+/* Compare no more than N characters of strings S1 and S2, ignoring case,
+   returning less than, equal to or greater than zero if S1 is
+   lexicographically less than, equal to or greater than S2.
+   Note: This function can not work correctly in multibyte locales.  */
+#if ! HAVE_DECL_STRNCASECMP
+extern int strncasecmp (const char *s1, const char *s2, size_t n);
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* _STRCASE_H */
diff --git a/src/bin/m4/lib/strcasecmp.c b/src/bin/m4/lib/strcasecmp.c
new file mode 100644
index 0000000000..99d5dd22a3
--- /dev/null
+++ b/src/bin/m4/lib/strcasecmp.c
@@ -0,0 +1,103 @@
+/* Case-insensitive string comparison function.
+   Copyright (C) 1998-1999, 2005-2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2005,
+   based on earlier glibc code.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "strcase.h"
+
+#include <ctype.h>
+#include <limits.h>
+
+#if HAVE_MBRTOWC
+# include "mbuiter.h"
+#endif
+
+#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
+
+/* Compare strings S1 and S2, ignoring case, returning less than, equal to or
+   greater than zero if S1 is lexicographically less than, equal to or greater
+   than S2.
+   Note: This function may, in multibyte locales, return 0 for strings of
+   different lengths!  */
+int
+strcasecmp (const char *s1, const char *s2)
+{
+  if (s1 == s2)
+    return 0;
+
+  /* Be careful not to look at the entire extent of s1 or s2 until needed.
+     This is useful because when two strings differ, the difference is
+     most often already in the very few first characters.  */
+#if HAVE_MBRTOWC
+  if (MB_CUR_MAX > 1)
+    {
+      mbui_iterator_t iter1;
+      mbui_iterator_t iter2;
+
+      mbui_init (iter1, s1);
+      mbui_init (iter2, s2);
+
+      while (mbui_avail (iter1) && mbui_avail (iter2))
+	{
+	  int cmp = mb_casecmp (mbui_cur (iter1), mbui_cur (iter2));
+
+	  if (cmp != 0)
+	    return cmp;
+
+	  mbui_advance (iter1);
+	  mbui_advance (iter2);
+	}
+      if (mbui_avail (iter1))
+	/* s2 terminated before s1.  */
+	return 1;
+      if (mbui_avail (iter2))
+	/* s1 terminated before s2.  */
+	return -1;
+      return 0;
+    }
+  else
+#endif
+    {
+      const unsigned char *p1 = (const unsigned char *) s1;
+      const unsigned char *p2 = (const unsigned char *) s2;
+      unsigned char c1, c2;
+
+      do
+	{
+	  c1 = TOLOWER (*p1);
+	  c2 = TOLOWER (*p2);
+
+	  if (c1 == '\0')
+	    break;
+
+	  ++p1;
+	  ++p2;
+	}
+      while (c1 == c2);
+
+      if (UCHAR_MAX <= INT_MAX)
+	return c1 - c2;
+      else
+	/* On machines where 'char' and 'int' are types of the same size, the
+	   difference of two 'unsigned char' values - including the sign bit -
+	   doesn't fit in an 'int'.  */
+	return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
+    }
+}
diff --git a/src/bin/m4/lib/strncasecmp.c b/src/bin/m4/lib/strncasecmp.c
new file mode 100644
index 0000000000..f59b953a7d
--- /dev/null
+++ b/src/bin/m4/lib/strncasecmp.c
@@ -0,0 +1,63 @@
+/* strncasecmp.c -- case insensitive string comparator
+   Copyright (C) 1998-1999, 2005-2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "strcase.h"
+
+#include <ctype.h>
+#include <limits.h>
+
+#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
+
+/* Compare no more than N bytes of strings S1 and S2,
+   ignoring case, returning less than, equal to or
+   greater than zero if S1 is lexicographically less
+   than, equal to or greater than S2.  */
+
+int
+strncasecmp (const char *s1, const char *s2, size_t n)
+{
+  register const unsigned char *p1 = (const unsigned char *) s1;
+  register const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+
+  if (p1 == p2 || n == 0)
+    return 0;
+
+  do
+    {
+      c1 = TOLOWER (*p1);
+      c2 = TOLOWER (*p2);
+
+      if (--n == 0 || c1 == '\0')
+	break;
+
+      ++p1;
+      ++p2;
+    }
+  while (c1 == c2);
+
+  if (UCHAR_MAX <= INT_MAX)
+    return c1 - c2;
+  else
+    /* On machines where 'char' and 'int' are types of the same size, the
+       difference of two 'unsigned char' values - including the sign bit -
+       doesn't fit in an 'int'.  */
+    return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
+}
diff --git a/src/bin/m4/lib/strnlen1.c b/src/bin/m4/lib/strnlen1.c
new file mode 100644
index 0000000000..422ed9e80c
--- /dev/null
+++ b/src/bin/m4/lib/strnlen1.c
@@ -0,0 +1,36 @@
+/* Find the length of STRING + 1, but scan at most MAXLEN bytes.
+   Copyright (C) 2005-2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "strnlen1.h"
+
+#include <string.h>
+
+/* Find the length of STRING + 1, but scan at most MAXLEN bytes.
+   If no '\0' terminator is found in that many characters, return MAXLEN.  */
+/* This is the same as strnlen (string, maxlen - 1) + 1.  */
+size_t
+strnlen1 (const char *string, size_t maxlen)
+{
+  const char *end = (const char *) memchr (string, '\0', maxlen);
+  if (end != NULL)
+    return end - string + 1;
+  else
+    return maxlen;
+}
diff --git a/src/bin/m4/lib/strnlen1.h b/src/bin/m4/lib/strnlen1.h
new file mode 100644
index 0000000000..7ce7d0c803
--- /dev/null
+++ b/src/bin/m4/lib/strnlen1.h
@@ -0,0 +1,40 @@
+/* Find the length of STRING + 1, but scan at most MAXLEN bytes.
+   Copyright (C) 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _STRNLEN1_H
+#define _STRNLEN1_H
+
+#include <stddef.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Find the length of STRING + 1, but scan at most MAXLEN bytes.
+   If no '\0' terminator is found in that many characters, return MAXLEN.  */
+/* This is the same as strnlen (string, maxlen - 1) + 1.  */
+extern size_t strnlen1 (const char *string, size_t maxlen);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* _STRNLEN1_H */
diff --git a/src/bin/m4/lib/strstr.c b/src/bin/m4/lib/strstr.c
new file mode 100644
index 0000000000..f1e2ef6988
--- /dev/null
+++ b/src/bin/m4/lib/strstr.c
@@ -0,0 +1,126 @@
+/* Searching in a string.
+   Copyright (C) 2005-2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2005.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "strstr.h"
+
+#include <stddef.h>  /* for NULL */
+
+#if HAVE_MBRTOWC
+# include "mbuiter.h"
+#endif
+
+/* Find the first occurrence of NEEDLE in HAYSTACK.  */
+char *
+strstr (const char *haystack, const char *needle)
+{
+  /* Be careful not to look at the entire extent of haystack or needle
+     until needed.  This is useful because of these two cases:
+       - haystack may be very long, and a match of needle found early,
+       - needle may be very long, and not even a short initial segment of
+         needle may be found in haystack.  */
+#if HAVE_MBRTOWC
+  if (MB_CUR_MAX > 1)
+    {
+      mbui_iterator_t iter_needle;
+
+      mbui_init (iter_needle, needle);
+      if (mbui_avail (iter_needle))
+	{
+	  mbui_iterator_t iter_haystack;
+
+	  mbui_init (iter_haystack, haystack);
+	  for (;; mbui_advance (iter_haystack))
+	    {
+	      if (!mbui_avail (iter_haystack))
+		/* No match.  */
+		return NULL;
+
+	      if (mb_equal (mbui_cur (iter_haystack), mbui_cur (iter_needle)))
+		/* The first character matches.  */
+		{
+		  mbui_iterator_t rhaystack;
+		  mbui_iterator_t rneedle;
+
+		  memcpy (&rhaystack, &iter_haystack, sizeof (mbui_iterator_t));
+		  mbui_advance (rhaystack);
+
+		  mbui_init (rneedle, needle);
+		  if (!mbui_avail (rneedle))
+		    abort ();
+		  mbui_advance (rneedle);
+
+		  for (;; mbui_advance (rhaystack), mbui_advance (rneedle))
+		    {
+		      if (!mbui_avail (rneedle))
+			/* Found a match.  */
+			return (char *) mbui_cur_ptr (iter_haystack);
+		      if (!mbui_avail (rhaystack))
+			/* No match.  */
+			return NULL;
+		      if (!mb_equal (mbui_cur (rhaystack), mbui_cur (rneedle)))
+			/* Nothing in this round.  */
+			break;
+		    }
+		}
+	    }
+	}
+      else
+	return (char *) haystack;
+    }
+  else
+#endif
+    {
+      if (*needle != '\0')
+	{
+	  /* Speed up the following searches of needle by caching its first
+	     character.  */
+	  char b = *needle++;
+
+	  for (;; haystack++)
+	    {
+	      if (*haystack == '\0')
+		/* No match.  */
+		return NULL;
+	      if (*haystack == b)
+		/* The first character matches.  */
+		{
+		  const char *rhaystack = haystack + 1;
+		  const char *rneedle = needle;
+
+		  for (;; rhaystack++, rneedle++)
+		    {
+		      if (*rneedle == '\0')
+			/* Found a match.  */
+			return (char *) haystack;
+		      if (*rhaystack == '\0')
+			/* No match.  */
+			return NULL;
+		      if (*rhaystack != *rneedle)
+			/* Nothing in this round.  */
+			break;
+		    }
+		}
+	    }
+	}
+      else
+	return (char *) haystack;
+    }
+}
diff --git a/src/bin/m4/lib/strstr.h b/src/bin/m4/lib/strstr.h
new file mode 100644
index 0000000000..a28b1401ea
--- /dev/null
+++ b/src/bin/m4/lib/strstr.h
@@ -0,0 +1,37 @@
+/* Searching in a string.
+   Copyright (C) 2001-2003, 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+
+/* Include string.h: on glibc systems, it contains a macro definition of
+   strstr() that would collide with our definition if included afterwards.  */
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* No known system has a strstr() function that works correctly in
+   multibyte locales. Therefore we use our version always.  */
+#undef strstr
+#define strstr rpl_strstr
+
+/* Find the first occurrence of NEEDLE in HAYSTACK.  */
+extern char *strstr (const char *haystack, const char *needle);
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/src/bin/m4/lib/strtol.c b/src/bin/m4/lib/strtol.c
new file mode 100644
index 0000000000..e409d28727
--- /dev/null
+++ b/src/bin/m4/lib/strtol.c
@@ -0,0 +1,437 @@
+/* Convert string representation of a number into an integer value.
+
+   Copyright (C) 1991, 1992, 1994, 1995, 1996, 1997, 1998, 1999, 2003, 2005, 2006
+   Free Software Foundation, Inc.
+
+   NOTE: The canonical source of this file is maintained with the GNU C
+   Library.  Bugs can be reported to bug-glibc@gnu.org.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by the
+   Free Software Foundation; either version 2, or (at your option) any
+   later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifdef _LIBC
+# define USE_NUMBER_GROUPING
+#else
+# include <config.h>
+#endif
+
+#include <ctype.h>
+#include <errno.h>
+#ifndef __set_errno
+# define __set_errno(Val) errno = (Val)
+#endif
+
+#include <limits.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef USE_NUMBER_GROUPING
+# include "../locale/localeinfo.h"
+#endif
+
+/* Nonzero if we are defining `strtoul' or `strtoull', operating on
+   unsigned integers.  */
+#ifndef UNSIGNED
+# define UNSIGNED 0
+# define INT LONG int
+#else
+# define INT unsigned LONG int
+#endif
+
+/* Determine the name.  */
+#ifdef USE_IN_EXTENDED_LOCALE_MODEL
+# if UNSIGNED
+#  ifdef USE_WIDE_CHAR
+#   ifdef QUAD
+#    define strtol __wcstoull_l
+#   else
+#    define strtol __wcstoul_l
+#   endif
+#  else
+#   ifdef QUAD
+#    define strtol __strtoull_l
+#   else
+#    define strtol __strtoul_l
+#   endif
+#  endif
+# else
+#  ifdef USE_WIDE_CHAR
+#   ifdef QUAD
+#    define strtol __wcstoll_l
+#   else
+#    define strtol __wcstol_l
+#   endif
+#  else
+#   ifdef QUAD
+#    define strtol __strtoll_l
+#   else
+#    define strtol __strtol_l
+#   endif
+#  endif
+# endif
+#else
+# if UNSIGNED
+#  ifdef USE_WIDE_CHAR
+#   ifdef QUAD
+#    define strtol wcstoull
+#   else
+#    define strtol wcstoul
+#   endif
+#  else
+#   ifdef QUAD
+#    define strtol strtoull
+#   else
+#    define strtol strtoul
+#   endif
+#  endif
+# else
+#  ifdef USE_WIDE_CHAR
+#   ifdef QUAD
+#    define strtol wcstoll
+#   else
+#    define strtol wcstol
+#   endif
+#  else
+#   ifdef QUAD
+#    define strtol strtoll
+#   endif
+#  endif
+# endif
+#endif
+
+/* If QUAD is defined, we are defining `strtoll' or `strtoull',
+   operating on `long long int's.  */
+#ifdef QUAD
+# define LONG long long
+# define STRTOL_LONG_MIN LONG_LONG_MIN
+# define STRTOL_LONG_MAX LONG_LONG_MAX
+# define STRTOL_ULONG_MAX ULONG_LONG_MAX
+
+/* The extra casts in the following macros work around compiler bugs,
+   e.g., in Cray C 5.0.3.0.  */
+
+/* True if negative values of the signed integer type T use two's
+   complement, ones' complement, or signed magnitude representation,
+   respectively.  Much GNU code assumes two's complement, but some
+   people like to be portable to all possible C hosts.  */
+# define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
+# define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
+# define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
+
+/* True if the arithmetic type T is signed.  */
+# define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
+
+/* The maximum and minimum values for the integer type T.  These
+   macros have undefined behavior if T is signed and has padding bits.
+   If this is a problem for you, please let us know how to fix it for
+   your host.  */
+# define TYPE_MINIMUM(t) \
+   ((t) (! TYPE_SIGNED (t) \
+	 ? (t) 0 \
+	 : TYPE_SIGNED_MAGNITUDE (t) \
+	 ? ~ (t) 0 \
+	 : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))
+# define TYPE_MAXIMUM(t) \
+   ((t) (! TYPE_SIGNED (t) \
+	 ? (t) -1 \
+	 : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
+
+# ifndef ULONG_LONG_MAX
+#  define ULONG_LONG_MAX TYPE_MAXIMUM (unsigned long long)
+# endif
+# ifndef LONG_LONG_MAX
+#  define LONG_LONG_MAX TYPE_MAXIMUM (long long int)
+# endif
+# ifndef LONG_LONG_MIN
+#  define LONG_LONG_MIN TYPE_MINIMUM (long long int)
+# endif
+
+# if __GNUC__ == 2 && __GNUC_MINOR__ < 7
+   /* Work around gcc bug with using this constant.  */
+   static const unsigned long long int maxquad = ULONG_LONG_MAX;
+#  undef STRTOL_ULONG_MAX
+#  define STRTOL_ULONG_MAX maxquad
+# endif
+#else
+# define LONG long
+# define STRTOL_LONG_MIN LONG_MIN
+# define STRTOL_LONG_MAX LONG_MAX
+# define STRTOL_ULONG_MAX ULONG_MAX
+#endif
+
+
+/* We use this code also for the extended locale handling where the
+   function gets as an additional argument the locale which has to be
+   used.  To access the values we have to redefine the _NL_CURRENT
+   macro.  */
+#ifdef USE_IN_EXTENDED_LOCALE_MODEL
+# undef _NL_CURRENT
+# define _NL_CURRENT(category, item) \
+  (current->values[_NL_ITEM_INDEX (item)].string)
+# define LOCALE_PARAM , loc
+# define LOCALE_PARAM_PROTO , __locale_t loc
+#else
+# define LOCALE_PARAM
+# define LOCALE_PARAM_PROTO
+#endif
+
+#if defined _LIBC || defined HAVE_WCHAR_H
+# include <wchar.h>
+#endif
+
+#ifdef USE_WIDE_CHAR
+# include <wctype.h>
+# define L_(Ch) L##Ch
+# define UCHAR_TYPE wint_t
+# define STRING_TYPE wchar_t
+# ifdef USE_IN_EXTENDED_LOCALE_MODEL
+#  define ISSPACE(Ch) __iswspace_l ((Ch), loc)
+#  define ISALPHA(Ch) __iswalpha_l ((Ch), loc)
+#  define TOUPPER(Ch) __towupper_l ((Ch), loc)
+# else
+#  define ISSPACE(Ch) iswspace (Ch)
+#  define ISALPHA(Ch) iswalpha (Ch)
+#  define TOUPPER(Ch) towupper (Ch)
+# endif
+#else
+# define L_(Ch) Ch
+# define UCHAR_TYPE unsigned char
+# define STRING_TYPE char
+# ifdef USE_IN_EXTENDED_LOCALE_MODEL
+#  define ISSPACE(Ch) __isspace_l ((Ch), loc)
+#  define ISALPHA(Ch) __isalpha_l ((Ch), loc)
+#  define TOUPPER(Ch) __toupper_l ((Ch), loc)
+# else
+#  define ISSPACE(Ch) isspace (Ch)
+#  define ISALPHA(Ch) isalpha (Ch)
+#  define TOUPPER(Ch) toupper (Ch)
+# endif
+#endif
+
+#define INTERNAL(X) INTERNAL1(X)
+#define INTERNAL1(X) __##X##_internal
+#define WEAKNAME(X) WEAKNAME1(X)
+
+#ifdef USE_NUMBER_GROUPING
+/* This file defines a function to check for correct grouping.  */
+# include "grouping.h"
+#endif
+
+
+
+/* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
+   If BASE is 0 the base is determined by the presence of a leading
+   zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
+   If BASE is < 2 or > 36, it is reset to 10.
+   If ENDPTR is not NULL, a pointer to the character after the last
+   one converted is stored in *ENDPTR.  */
+
+INT
+INTERNAL (strtol) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
+		   int base, int group LOCALE_PARAM_PROTO)
+{
+  int negative;
+  register unsigned LONG int cutoff;
+  register unsigned int cutlim;
+  register unsigned LONG int i;
+  register const STRING_TYPE *s;
+  register UCHAR_TYPE c;
+  const STRING_TYPE *save, *end;
+  int overflow;
+
+#ifdef USE_NUMBER_GROUPING
+# ifdef USE_IN_EXTENDED_LOCALE_MODEL
+  struct locale_data *current = loc->__locales[LC_NUMERIC];
+# endif
+  /* The thousands character of the current locale.  */
+  wchar_t thousands = L'\0';
+  /* The numeric grouping specification of the current locale,
+     in the format described in <locale.h>.  */
+  const char *grouping;
+
+  if (group)
+    {
+      grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
+      if (*grouping <= 0 || *grouping == CHAR_MAX)
+	grouping = NULL;
+      else
+	{
+	  /* Figure out the thousands separator character.  */
+# if defined _LIBC || defined _HAVE_BTOWC
+	  thousands = __btowc (*_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP));
+	  if (thousands == WEOF)
+	    thousands = L'\0';
+# endif
+	  if (thousands == L'\0')
+	    grouping = NULL;
+	}
+    }
+  else
+    grouping = NULL;
+#endif
+
+  if (base < 0 || base == 1 || base > 36)
+    {
+      __set_errno (EINVAL);
+      return 0;
+    }
+
+  save = s = nptr;
+
+  /* Skip white space.  */
+  while (ISSPACE (*s))
+    ++s;
+  if (*s == L_('\0'))
+    goto noconv;
+
+  /* Check for a sign.  */
+  if (*s == L_('-'))
+    {
+      negative = 1;
+      ++s;
+    }
+  else if (*s == L_('+'))
+    {
+      negative = 0;
+      ++s;
+    }
+  else
+    negative = 0;
+
+  /* Recognize number prefix and if BASE is zero, figure it out ourselves.  */
+  if (*s == L_('0'))
+    {
+      if ((base == 0 || base == 16) && TOUPPER (s[1]) == L_('X'))
+	{
+	  s += 2;
+	  base = 16;
+	}
+      else if (base == 0)
+	base = 8;
+    }
+  else if (base == 0)
+    base = 10;
+
+  /* Save the pointer so we can check later if anything happened.  */
+  save = s;
+
+#ifdef USE_NUMBER_GROUPING
+  if (group)
+    {
+      /* Find the end of the digit string and check its grouping.  */
+      end = s;
+      for (c = *end; c != L_('\0'); c = *++end)
+	if ((wchar_t) c != thousands
+	    && ((wchar_t) c < L_('0') || (wchar_t) c > L_('9'))
+	    && (!ISALPHA (c) || (int) (TOUPPER (c) - L_('A') + 10) >= base))
+	  break;
+      if (*s == thousands)
+	end = s;
+      else
+	end = correctly_grouped_prefix (s, end, thousands, grouping);
+    }
+  else
+#endif
+    end = NULL;
+
+  cutoff = STRTOL_ULONG_MAX / (unsigned LONG int) base;
+  cutlim = STRTOL_ULONG_MAX % (unsigned LONG int) base;
+
+  overflow = 0;
+  i = 0;
+  for (c = *s; c != L_('\0'); c = *++s)
+    {
+      if (s == end)
+	break;
+      if (c >= L_('0') && c <= L_('9'))
+	c -= L_('0');
+      else if (ISALPHA (c))
+	c = TOUPPER (c) - L_('A') + 10;
+      else
+	break;
+      if ((int) c >= base)
+	break;
+      /* Check for overflow.  */
+      if (i > cutoff || (i == cutoff && c > cutlim))
+	overflow = 1;
+      else
+	{
+	  i *= (unsigned LONG int) base;
+	  i += c;
+	}
+    }
+
+  /* Check if anything actually happened.  */
+  if (s == save)
+    goto noconv;
+
+  /* Store in ENDPTR the address of one character
+     past the last character we converted.  */
+  if (endptr != NULL)
+    *endptr = (STRING_TYPE *) s;
+
+#if !UNSIGNED
+  /* Check for a value that is within the range of
+     `unsigned LONG int', but outside the range of `LONG int'.  */
+  if (overflow == 0
+      && i > (negative
+	      ? -((unsigned LONG int) (STRTOL_LONG_MIN + 1)) + 1
+	      : (unsigned LONG int) STRTOL_LONG_MAX))
+    overflow = 1;
+#endif
+
+  if (overflow)
+    {
+      __set_errno (ERANGE);
+#if UNSIGNED
+      return STRTOL_ULONG_MAX;
+#else
+      return negative ? STRTOL_LONG_MIN : STRTOL_LONG_MAX;
+#endif
+    }
+
+  /* Return the result of the appropriate sign.  */
+  return negative ? -i : i;
+
+noconv:
+  /* We must handle a special case here: the base is 0 or 16 and the
+     first two characters are '0' and 'x', but the rest are no
+     hexadecimal digits.  This is no error case.  We return 0 and
+     ENDPTR points to the `x`.  */
+  if (endptr != NULL)
+    {
+      if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
+	  && save[-2] == L_('0'))
+	*endptr = (STRING_TYPE *) &save[-1];
+      else
+	/*  There was no number to convert.  */
+	*endptr = (STRING_TYPE *) nptr;
+    }
+
+  return 0L;
+}
+
+/* External user entry point.  */
+
+
+INT
+#ifdef weak_function
+weak_function
+#endif
+strtol (const STRING_TYPE *nptr, STRING_TYPE **endptr,
+	int base LOCALE_PARAM_PROTO)
+{
+  return INTERNAL (strtol) (nptr, endptr, base, 0 LOCALE_PARAM);
+}
diff --git a/src/bin/m4/lib/tempname.c b/src/bin/m4/lib/tempname.c
new file mode 100644
index 0000000000..919badb3dc
--- /dev/null
+++ b/src/bin/m4/lib/tempname.c
@@ -0,0 +1,322 @@
+/* tempname.c - generate the name of a temporary file.
+
+   Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+   2000, 2001, 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Extracted from glibc sysdeps/posix/tempname.c.  See also tmpdir.c.  */
+
+#if !_LIBC
+# include <config.h>
+# include "tempname.h"
+#endif
+
+#include <sys/types.h>
+#include <assert.h>
+
+#include <errno.h>
+#ifndef __set_errno
+# define __set_errno(Val) errno = (Val)
+#endif
+
+#include <stdio.h>
+#ifndef P_tmpdir
+# define P_tmpdir "/tmp"
+#endif
+#ifndef TMP_MAX
+# define TMP_MAX 238328
+#endif
+#ifndef __GT_FILE
+# define __GT_FILE	0
+# define __GT_BIGFILE	1
+# define __GT_DIR	2
+# define __GT_NOCREATE	3
+#endif
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <fcntl.h>
+
+#if HAVE_SYS_TIME_H || _LIBC
+# include <sys/time.h>
+#endif
+
+#include <stdint.h>
+#include <unistd.h>
+
+#include <sys/stat.h>
+
+#if _LIBC
+# define struct_stat64 struct stat64
+# define small_open __open
+# define large_open __open64
+#else
+# define struct_stat64 struct stat
+# define small_open open
+# define large_open open
+# define __gen_tempname gen_tempname
+# define __getpid getpid
+# define __gettimeofday gettimeofday
+# define __mkdir mkdir
+# define __lxstat64(version, file, buf) lstat (file, buf)
+# define __xstat64(version, file, buf) stat (file, buf)
+#endif
+
+#if ! (HAVE___SECURE_GETENV || _LIBC)
+# define __secure_getenv getenv
+#endif
+
+#ifdef _LIBC
+# include <hp-timing.h>
+# if HP_TIMING_AVAIL
+#  define RANDOM_BITS(Var) \
+  if (__builtin_expect (value == UINT64_C (0), 0))			      \
+    {									      \
+      /* If this is the first time this function is used initialize	      \
+	 the variable we accumulate the value in to some somewhat	      \
+	 random value.  If we'd not do this programs at startup time	      \
+	 might have a reduced set of possible names, at least on slow	      \
+	 machines.  */							      \
+      struct timeval tv;						      \
+      __gettimeofday (&tv, NULL);					      \
+      value = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;		      \
+    }									      \
+  HP_TIMING_NOW (Var)
+# endif
+#endif
+
+/* Use the widest available unsigned type if uint64_t is not
+   available.  The algorithm below extracts a number less than 62**6
+   (approximately 2**35.725) from uint64_t, so ancient hosts where
+   uintmax_t is only 32 bits lose about 3.725 bits of randomness,
+   which is better than not having mkstemp at all.  */
+#if !defined UINT64_MAX && !defined uint64_t
+# define uint64_t uintmax_t
+#endif
+
+#if _LIBC
+/* Return nonzero if DIR is an existent directory.  */
+static int
+direxists (const char *dir)
+{
+  struct_stat64 buf;
+  return __xstat64 (_STAT_VER, dir, &buf) == 0 && S_ISDIR (buf.st_mode);
+}
+
+/* Path search algorithm, for tmpnam, tmpfile, etc.  If DIR is
+   non-null and exists, uses it; otherwise uses the first of $TMPDIR,
+   P_tmpdir, /tmp that exists.  Copies into TMPL a template suitable
+   for use with mk[s]temp.  Will fail (-1) if DIR is non-null and
+   doesn't exist, none of the searched dirs exists, or there's not
+   enough space in TMPL. */
+int
+__path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
+	       int try_tmpdir)
+{
+  const char *d;
+  size_t dlen, plen;
+
+  if (!pfx || !pfx[0])
+    {
+      pfx = "file";
+      plen = 4;
+    }
+  else
+    {
+      plen = strlen (pfx);
+      if (plen > 5)
+	plen = 5;
+    }
+
+  if (try_tmpdir)
+    {
+      d = __secure_getenv ("TMPDIR");
+      if (d != NULL && direxists (d))
+	dir = d;
+      else if (dir != NULL && direxists (dir))
+	/* nothing */ ;
+      else
+	dir = NULL;
+    }
+  if (dir == NULL)
+    {
+      if (direxists (P_tmpdir))
+	dir = P_tmpdir;
+      else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
+	dir = "/tmp";
+      else
+	{
+	  __set_errno (ENOENT);
+	  return -1;
+	}
+    }
+
+  dlen = strlen (dir);
+  while (dlen > 1 && dir[dlen - 1] == '/')
+    dlen--;			/* remove trailing slashes */
+
+  /* check we have room for "${dir}/${pfx}XXXXXX\0" */
+  if (tmpl_len < dlen + 1 + plen + 6 + 1)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  sprintf (tmpl, "%.*s/%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
+  return 0;
+}
+#endif /* _LIBC */
+
+/* These are the characters used in temporary file names.  */
+static const char letters[] =
+"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+/* Generate a temporary file name based on TMPL.  TMPL must match the
+   rules for mk[s]temp (i.e. end in "XXXXXX").  The name constructed
+   does not exist at the time of the call to __gen_tempname.  TMPL is
+   overwritten with the result.
+
+   KIND may be one of:
+   __GT_NOCREATE:	simply verify that the name does not exist
+			at the time of the call.
+   __GT_FILE:		create the file using open(O_CREAT|O_EXCL)
+			and return a read-write fd.  The file is mode 0600.
+   __GT_BIGFILE:	same as __GT_FILE but use open64().
+   __GT_DIR:		create a directory, which will be mode 0700.
+
+   We use a clever algorithm to get hard-to-predict names. */
+int
+__gen_tempname (char *tmpl, int kind)
+{
+  int len;
+  char *XXXXXX;
+  static uint64_t value;
+  uint64_t random_time_bits;
+  unsigned int count;
+  int fd = -1;
+  int save_errno = errno;
+  struct_stat64 st;
+
+  /* A lower bound on the number of temporary files to attempt to
+     generate.  The maximum total number of temporary file names that
+     can exist for a given template is 62**6.  It should never be
+     necessary to try all these combinations.  Instead if a reasonable
+     number of names is tried (we define reasonable as 62**3) fail to
+     give the system administrator the chance to remove the problems.  */
+#define ATTEMPTS_MIN (62 * 62 * 62)
+
+  /* The number of times to attempt to generate a temporary file.  To
+     conform to POSIX, this must be no smaller than TMP_MAX.  */
+#if ATTEMPTS_MIN < TMP_MAX
+  unsigned int attempts = TMP_MAX;
+#else
+  unsigned int attempts = ATTEMPTS_MIN;
+#endif
+
+  len = strlen (tmpl);
+  if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  /* This is where the Xs start.  */
+  XXXXXX = &tmpl[len - 6];
+
+  /* Get some more or less random data.  */
+#ifdef RANDOM_BITS
+  RANDOM_BITS (random_time_bits);
+#else
+# if HAVE_GETTIMEOFDAY || _LIBC
+  {
+    struct timeval tv;
+    __gettimeofday (&tv, NULL);
+    random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
+  }
+# else
+  random_time_bits = time (NULL);
+# endif
+#endif
+  value += random_time_bits ^ __getpid ();
+
+  for (count = 0; count < attempts; value += 7777, ++count)
+    {
+      uint64_t v = value;
+
+      /* Fill in the random bits.  */
+      XXXXXX[0] = letters[v % 62];
+      v /= 62;
+      XXXXXX[1] = letters[v % 62];
+      v /= 62;
+      XXXXXX[2] = letters[v % 62];
+      v /= 62;
+      XXXXXX[3] = letters[v % 62];
+      v /= 62;
+      XXXXXX[4] = letters[v % 62];
+      v /= 62;
+      XXXXXX[5] = letters[v % 62];
+
+      switch (kind)
+	{
+	case __GT_FILE:
+	  fd = small_open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+	  break;
+
+	case __GT_BIGFILE:
+	  fd = large_open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+	  break;
+
+	case __GT_DIR:
+	  fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
+	  break;
+
+	case __GT_NOCREATE:
+	  /* This case is backward from the other three.  __gen_tempname
+	     succeeds if __xstat fails because the name does not exist.
+	     Note the continue to bypass the common logic at the bottom
+	     of the loop.  */
+	  if (__lxstat64 (_STAT_VER, tmpl, &st) < 0)
+	    {
+	      if (errno == ENOENT)
+		{
+		  __set_errno (save_errno);
+		  return 0;
+		}
+	      else
+		/* Give up now. */
+		return -1;
+	    }
+	  continue;
+
+	default:
+	  assert (! "invalid KIND in __gen_tempname");
+	}
+
+      if (fd >= 0)
+	{
+	  __set_errno (save_errno);
+	  return fd;
+	}
+      else if (errno != EEXIST)
+	return -1;
+    }
+
+  /* We got out of the loop because we ran out of combinations to try.  */
+  __set_errno (EEXIST);
+  return -1;
+}
diff --git a/src/bin/m4/lib/tempname.h b/src/bin/m4/lib/tempname.h
new file mode 100644
index 0000000000..c51fa69424
--- /dev/null
+++ b/src/bin/m4/lib/tempname.h
@@ -0,0 +1,40 @@
+/* Create a temporary file or directory.
+
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* header written by Eric Blake */
+
+/* In gnulib, always prefer large files.  GT_FILE maps to
+   __GT_BIGFILE, not __GT_FILE, for a reason.  */
+#define GT_FILE		1
+#define GT_DIR		2
+#define GT_NOCREATE	3
+
+/* Generate a temporary file name based on TMPL.  TMPL must match the
+   rules for mk[s]temp (i.e. end in "XXXXXX").  The name constructed
+   does not exist at the time of the call to gen_tempname.  TMPL is
+   overwritten with the result.
+
+   KIND may be one of:
+   GT_NOCREATE:		simply verify that the name does not exist
+			at the time of the call.
+   GT_FILE:		create a large file using open(O_CREAT|O_EXCL)
+			and return a read-write fd.  The file is mode 0600.
+   GT_DIR:		create a directory, which will be mode 0700.
+
+   We use a clever algorithm to get hard-to-predict names. */
+extern int gen_tempname (char *tmpl, int kind);
diff --git a/src/bin/m4/lib/tmpdir.c b/src/bin/m4/lib/tmpdir.c
new file mode 100644
index 0000000000..d29a005789
--- /dev/null
+++ b/src/bin/m4/lib/tmpdir.c
@@ -0,0 +1,133 @@
+/* Copyright (C) 1999, 2001-2002, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Extracted from sysdeps/posix/tempname.c.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "tmpdir.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <errno.h>
+#ifndef __set_errno
+# define __set_errno(Val) errno = (Val)
+#endif
+
+#include <stdio.h>
+#ifndef P_tmpdir
+# define P_tmpdir "/tmp"
+#endif
+
+#include <sys/stat.h>
+
+#if _LIBC
+# define struct_stat64 struct stat64
+#else
+# define struct_stat64 struct stat
+# define __xstat64(version, path, buf) stat (path, buf)
+#endif
+
+#if ! (HAVE___SECURE_GETENV || _LIBC)
+# define __secure_getenv getenv
+#endif
+
+/* Pathname support.
+   ISSLASH(C)           tests whether C is a directory separator character.
+ */
+#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
+  /* Win32, Cygwin, OS/2, DOS */
+# define ISSLASH(C) ((C) == '/' || (C) == '\\')
+#else
+  /* Unix */
+# define ISSLASH(C) ((C) == '/')
+#endif
+
+
+/* Return nonzero if DIR is an existent directory.  */
+static bool
+direxists (const char *dir)
+{
+  struct_stat64 buf;
+  return __xstat64 (_STAT_VER, dir, &buf) == 0 && S_ISDIR (buf.st_mode);
+}
+
+/* Path search algorithm, for tmpnam, tmpfile, etc.  If DIR is
+   non-null and exists, uses it; otherwise uses the first of $TMPDIR,
+   P_tmpdir, /tmp that exists.  Copies into TMPL a template suitable
+   for use with mk[s]temp.  Will fail (-1) if DIR is non-null and
+   doesn't exist, none of the searched dirs exists, or there's not
+   enough space in TMPL. */
+int
+path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
+	     bool try_tmpdir)
+{
+  const char *d;
+  size_t dlen, plen;
+
+  if (!pfx || !pfx[0])
+    {
+      pfx = "file";
+      plen = 4;
+    }
+  else
+    {
+      plen = strlen (pfx);
+      if (plen > 5)
+	plen = 5;
+    }
+
+  if (try_tmpdir)
+    {
+      d = __secure_getenv ("TMPDIR");
+      if (d != NULL && direxists (d))
+	dir = d;
+      else if (dir != NULL && direxists (dir))
+	/* nothing */ ;
+      else
+	dir = NULL;
+    }
+  if (dir == NULL)
+    {
+      if (direxists (P_tmpdir))
+	dir = P_tmpdir;
+      else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
+	dir = "/tmp";
+      else
+	{
+	  __set_errno (ENOENT);
+	  return -1;
+	}
+    }
+
+  dlen = strlen (dir);
+  while (dlen >= 1 && ISSLASH (dir[dlen - 1]))
+    dlen--;			/* remove trailing slashes */
+
+  /* check we have room for "${dir}/${pfx}XXXXXX\0" */
+  if (tmpl_len < dlen + 1 + plen + 6 + 1)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  sprintf (tmpl, "%.*s/%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
+  return 0;
+}
diff --git a/src/bin/m4/lib/tmpdir.h b/src/bin/m4/lib/tmpdir.h
new file mode 100644
index 0000000000..454e5cc184
--- /dev/null
+++ b/src/bin/m4/lib/tmpdir.h
@@ -0,0 +1,27 @@
+/* Determine a temporary directory.
+   Copyright (C) 2001-2002 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <stdbool.h>
+#include <stddef.h>
+
+/* Path search algorithm, for tmpnam, tmpfile, etc.  If DIR is
+   non-null and exists, uses it; otherwise uses the first of $TMPDIR,
+   P_tmpdir, /tmp that exists.  Copies into TMPL a template suitable
+   for use with mk[s]temp.  Will fail (-1) if DIR is non-null and
+   doesn't exist, none of the searched dirs exists, or there's not
+   enough space in TMPL. */
+extern int path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx, bool try_tmpdir);
diff --git a/src/bin/m4/lib/unistd--.h b/src/bin/m4/lib/unistd--.h
new file mode 100644
index 0000000000..1fe6ce8b27
--- /dev/null
+++ b/src/bin/m4/lib/unistd--.h
@@ -0,0 +1,28 @@
+/* Like unistd.h, but redefine some names to avoid glitches.
+
+   Copyright (C) 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <unistd.h>
+#include "unistd-safer.h"
+
+#undef dup
+#define dup dup_safer
+
+#undef pipe
+#define pipe pipe_safer
diff --git a/src/bin/m4/lib/unistd-safer.h b/src/bin/m4/lib/unistd-safer.h
new file mode 100644
index 0000000000..f95999d391
--- /dev/null
+++ b/src/bin/m4/lib/unistd-safer.h
@@ -0,0 +1,23 @@
+/* Invoke unistd-like functions, but avoid some glitches.
+
+   Copyright (C) 2001, 2003, 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+int dup_safer (int);
+int fd_safer (int);
+int pipe_safer (int[2]);
diff --git a/src/bin/m4/lib/unlocked-io.h b/src/bin/m4/lib/unlocked-io.h
new file mode 100644
index 0000000000..d00930361c
--- /dev/null
+++ b/src/bin/m4/lib/unlocked-io.h
@@ -0,0 +1,137 @@
+/* Prefer faster, non-thread-safe stdio functions if available.
+
+   Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Jim Meyering.  */
+
+#ifndef UNLOCKED_IO_H
+# define UNLOCKED_IO_H 1
+
+/* These are wrappers for functions/macros from the GNU C library, and
+   from other C libraries supporting POSIX's optional thread-safe functions.
+
+   The standard I/O functions are thread-safe.  These *_unlocked ones are
+   more efficient but not thread-safe.  That they're not thread-safe is
+   fine since all of the applications in this package are single threaded.
+
+   Also, some code that is shared with the GNU C library may invoke
+   the *_unlocked functions directly.  On hosts that lack those
+   functions, invoke the non-thread-safe versions instead.  */
+
+# include <stdio.h>
+
+# if HAVE_DECL_CLEARERR_UNLOCKED
+#  undef clearerr
+#  define clearerr(x) clearerr_unlocked (x)
+# else
+#  define clearerr_unlocked(x) clearerr (x)
+# endif
+
+# if HAVE_DECL_FEOF_UNLOCKED
+#  undef feof
+#  define feof(x) feof_unlocked (x)
+# else
+#  define feof_unlocked(x) feof (x)
+# endif
+
+# if HAVE_DECL_FERROR_UNLOCKED
+#  undef ferror
+#  define ferror(x) ferror_unlocked (x)
+# else
+#  define ferror_unlocked(x) ferror (x)
+# endif
+
+# if HAVE_DECL_FFLUSH_UNLOCKED
+#  undef fflush
+#  define fflush(x) fflush_unlocked (x)
+# else
+#  define fflush_unlocked(x) fflush (x)
+# endif
+
+# if HAVE_DECL_FGETS_UNLOCKED
+#  undef fgets
+#  define fgets(x,y,z) fgets_unlocked (x,y,z)
+# else
+#  define fgets_unlocked(x,y,z) fgets (x,y,z)
+# endif
+
+# if HAVE_DECL_FPUTC_UNLOCKED
+#  undef fputc
+#  define fputc(x,y) fputc_unlocked (x,y)
+# else
+#  define fputc_unlocked(x,y) fputc (x,y)
+# endif
+
+# if HAVE_DECL_FPUTS_UNLOCKED
+#  undef fputs
+#  define fputs(x,y) fputs_unlocked (x,y)
+# else
+#  define fputs_unlocked(x,y) fputs (x,y)
+# endif
+
+# if HAVE_DECL_FREAD_UNLOCKED
+#  undef fread
+#  define fread(w,x,y,z) fread_unlocked (w,x,y,z)
+# else
+#  define fread_unlocked(w,x,y,z) fread (w,x,y,z)
+# endif
+
+# if HAVE_DECL_FWRITE_UNLOCKED
+#  undef fwrite
+#  define fwrite(w,x,y,z) fwrite_unlocked (w,x,y,z)
+# else
+#  define fwrite_unlocked(w,x,y,z) fwrite (w,x,y,z)
+# endif
+
+# if HAVE_DECL_GETC_UNLOCKED
+#  undef getc
+#  define getc(x) getc_unlocked (x)
+# else
+#  define getc_unlocked(x) getc (x)
+# endif
+
+# if HAVE_DECL_GETCHAR_UNLOCKED
+#  undef getchar
+#  define getchar() getchar_unlocked ()
+# else
+#  define getchar_unlocked() getchar ()
+# endif
+
+# if HAVE_DECL_PUTC_UNLOCKED
+#  undef putc
+#  define putc(x,y) putc_unlocked (x,y)
+# else
+#  define putc_unlocked(x,y) putc (x,y)
+# endif
+
+# if HAVE_DECL_PUTCHAR_UNLOCKED
+#  undef putchar
+#  define putchar(x) putchar_unlocked (x)
+# else
+#  define putchar_unlocked(x) putchar (x)
+# endif
+
+# undef flockfile
+# define flockfile(x) ((void) 0)
+
+# undef ftrylockfile
+# define ftrylockfile(x) 0
+
+# undef funlockfile
+# define funlockfile(x) ((void) 0)
+
+#endif /* UNLOCKED_IO_H */
diff --git a/src/bin/m4/lib/vasnprintf.c b/src/bin/m4/lib/vasnprintf.c
new file mode 100644
index 0000000000..0fe2aada9f
--- /dev/null
+++ b/src/bin/m4/lib/vasnprintf.c
@@ -0,0 +1,889 @@
+/* vsprintf with automatic memory allocation.
+   Copyright (C) 1999, 2002-2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Tell glibc's <stdio.h> to provide a prototype for snprintf().
+   This must come before <config.h> because <config.h> may include
+   <features.h>, and once <features.h> has been included, it's too late.  */
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE    1
+#endif
+
+#include <config.h>
+#ifndef IN_LIBINTL
+# include <alloca.h>
+#endif
+
+/* Specification.  */
+#if WIDE_CHAR_VERSION
+# include "vasnwprintf.h"
+#else
+# include "vasnprintf.h"
+#endif
+
+#include <stdio.h>	/* snprintf(), sprintf() */
+#include <stdlib.h>	/* abort(), malloc(), realloc(), free() */
+#include <string.h>	/* memcpy(), strlen() */
+#include <errno.h>	/* errno */
+#include <limits.h>	/* CHAR_BIT */
+#include <float.h>	/* DBL_MAX_EXP, LDBL_MAX_EXP */
+#if WIDE_CHAR_VERSION
+# include "wprintf-parse.h"
+#else
+# include "printf-parse.h"
+#endif
+
+/* Checked size_t computations.  */
+#include "xsize.h"
+
+#ifdef HAVE_WCHAR_T
+# ifdef HAVE_WCSLEN
+#  define local_wcslen wcslen
+# else
+   /* Solaris 2.5.1 has wcslen() in a separate library libw.so. To avoid
+      a dependency towards this library, here is a local substitute.
+      Define this substitute only once, even if this file is included
+      twice in the same compilation unit.  */
+#  ifndef local_wcslen_defined
+#   define local_wcslen_defined 1
+static size_t
+local_wcslen (const wchar_t *s)
+{
+  const wchar_t *ptr;
+
+  for (ptr = s; *ptr != (wchar_t) 0; ptr++)
+    ;
+  return ptr - s;
+}
+#  endif
+# endif
+#endif
+
+#if WIDE_CHAR_VERSION
+# define VASNPRINTF vasnwprintf
+# define CHAR_T wchar_t
+# define DIRECTIVE wchar_t_directive
+# define DIRECTIVES wchar_t_directives
+# define PRINTF_PARSE wprintf_parse
+# define USE_SNPRINTF 1
+# if HAVE_DECL__SNWPRINTF
+   /* On Windows, the function swprintf() has a different signature than
+      on Unix; we use the _snwprintf() function instead.  */
+#  define SNPRINTF _snwprintf
+# else
+   /* Unix.  */
+#  define SNPRINTF swprintf
+# endif
+#else
+# define VASNPRINTF vasnprintf
+# define CHAR_T char
+# define DIRECTIVE char_directive
+# define DIRECTIVES char_directives
+# define PRINTF_PARSE printf_parse
+# define USE_SNPRINTF (HAVE_DECL__SNPRINTF || HAVE_SNPRINTF)
+# if HAVE_DECL__SNPRINTF
+   /* Windows.  */
+#  define SNPRINTF _snprintf
+# else
+   /* Unix.  */
+#  define SNPRINTF snprintf
+# endif
+#endif
+
+CHAR_T *
+VASNPRINTF (CHAR_T *resultbuf, size_t *lengthp, const CHAR_T *format, va_list args)
+{
+  DIRECTIVES d;
+  arguments a;
+
+  if (PRINTF_PARSE (format, &d, &a) < 0)
+    {
+      errno = EINVAL;
+      return NULL;
+    }
+
+#define CLEANUP() \
+  free (d.dir);								\
+  if (a.arg)								\
+    free (a.arg);
+
+  if (printf_fetchargs (args, &a) < 0)
+    {
+      CLEANUP ();
+      errno = EINVAL;
+      return NULL;
+    }
+
+  {
+    size_t buf_neededlength;
+    CHAR_T *buf;
+    CHAR_T *buf_malloced;
+    const CHAR_T *cp;
+    size_t i;
+    DIRECTIVE *dp;
+    /* Output string accumulator.  */
+    CHAR_T *result;
+    size_t allocated;
+    size_t length;
+
+    /* Allocate a small buffer that will hold a directive passed to
+       sprintf or snprintf.  */
+    buf_neededlength =
+      xsum4 (7, d.max_width_length, d.max_precision_length, 6);
+#if HAVE_ALLOCA
+    if (buf_neededlength < 4000 / sizeof (CHAR_T))
+      {
+	buf = (CHAR_T *) alloca (buf_neededlength * sizeof (CHAR_T));
+	buf_malloced = NULL;
+      }
+    else
+#endif
+      {
+	size_t buf_memsize = xtimes (buf_neededlength, sizeof (CHAR_T));
+	if (size_overflow_p (buf_memsize))
+	  goto out_of_memory_1;
+	buf = (CHAR_T *) malloc (buf_memsize);
+	if (buf == NULL)
+	  goto out_of_memory_1;
+	buf_malloced = buf;
+      }
+
+    if (resultbuf != NULL)
+      {
+	result = resultbuf;
+	allocated = *lengthp;
+      }
+    else
+      {
+	result = NULL;
+	allocated = 0;
+      }
+    length = 0;
+    /* Invariants:
+       result is either == resultbuf or == NULL or malloc-allocated.
+       If length > 0, then result != NULL.  */
+
+    /* Ensures that allocated >= needed.  Aborts through a jump to
+       out_of_memory if needed is SIZE_MAX or otherwise too big.  */
+#define ENSURE_ALLOCATION(needed) \
+    if ((needed) > allocated)						     \
+      {									     \
+	size_t memory_size;						     \
+	CHAR_T *memory;							     \
+									     \
+	allocated = (allocated > 0 ? xtimes (allocated, 2) : 12);	     \
+	if ((needed) > allocated)					     \
+	  allocated = (needed);						     \
+	memory_size = xtimes (allocated, sizeof (CHAR_T));		     \
+	if (size_overflow_p (memory_size))				     \
+	  goto out_of_memory;						     \
+	if (result == resultbuf || result == NULL)			     \
+	  memory = (CHAR_T *) malloc (memory_size);			     \
+	else								     \
+	  memory = (CHAR_T *) realloc (result, memory_size);		     \
+	if (memory == NULL)						     \
+	  goto out_of_memory;						     \
+	if (result == resultbuf && length > 0)				     \
+	  memcpy (memory, result, length * sizeof (CHAR_T));		     \
+	result = memory;						     \
+      }
+
+    for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
+      {
+	if (cp != dp->dir_start)
+	  {
+	    size_t n = dp->dir_start - cp;
+	    size_t augmented_length = xsum (length, n);
+
+	    ENSURE_ALLOCATION (augmented_length);
+	    memcpy (result + length, cp, n * sizeof (CHAR_T));
+	    length = augmented_length;
+	  }
+	if (i == d.count)
+	  break;
+
+	/* Execute a single directive.  */
+	if (dp->conversion == '%')
+	  {
+	    size_t augmented_length;
+
+	    if (!(dp->arg_index == ARG_NONE))
+	      abort ();
+	    augmented_length = xsum (length, 1);
+	    ENSURE_ALLOCATION (augmented_length);
+	    result[length] = '%';
+	    length = augmented_length;
+	  }
+	else
+	  {
+	    if (!(dp->arg_index != ARG_NONE))
+	      abort ();
+
+	    if (dp->conversion == 'n')
+	      {
+		switch (a.arg[dp->arg_index].type)
+		  {
+		  case TYPE_COUNT_SCHAR_POINTER:
+		    *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
+		    break;
+		  case TYPE_COUNT_SHORT_POINTER:
+		    *a.arg[dp->arg_index].a.a_count_short_pointer = length;
+		    break;
+		  case TYPE_COUNT_INT_POINTER:
+		    *a.arg[dp->arg_index].a.a_count_int_pointer = length;
+		    break;
+		  case TYPE_COUNT_LONGINT_POINTER:
+		    *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
+		    break;
+#ifdef HAVE_LONG_LONG_INT
+		  case TYPE_COUNT_LONGLONGINT_POINTER:
+		    *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
+		    break;
+#endif
+		  default:
+		    abort ();
+		  }
+	      }
+	    else
+	      {
+		arg_type type = a.arg[dp->arg_index].type;
+		CHAR_T *p;
+		unsigned int prefix_count;
+		int prefixes[2];
+#if !USE_SNPRINTF
+		size_t tmp_length;
+		CHAR_T tmpbuf[700];
+		CHAR_T *tmp;
+
+		/* Allocate a temporary buffer of sufficient size for calling
+		   sprintf.  */
+		{
+		  size_t width;
+		  size_t precision;
+
+		  width = 0;
+		  if (dp->width_start != dp->width_end)
+		    {
+		      if (dp->width_arg_index != ARG_NONE)
+			{
+			  int arg;
+
+			  if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
+			    abort ();
+			  arg = a.arg[dp->width_arg_index].a.a_int;
+			  width = (arg < 0 ? (unsigned int) (-arg) : arg);
+			}
+		      else
+			{
+			  const CHAR_T *digitp = dp->width_start;
+
+			  do
+			    width = xsum (xtimes (width, 10), *digitp++ - '0');
+			  while (digitp != dp->width_end);
+			}
+		    }
+
+		  precision = 6;
+		  if (dp->precision_start != dp->precision_end)
+		    {
+		      if (dp->precision_arg_index != ARG_NONE)
+			{
+			  int arg;
+
+			  if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
+			    abort ();
+			  arg = a.arg[dp->precision_arg_index].a.a_int;
+			  precision = (arg < 0 ? 0 : arg);
+			}
+		      else
+			{
+			  const CHAR_T *digitp = dp->precision_start + 1;
+
+			  precision = 0;
+			  while (digitp != dp->precision_end)
+			    precision = xsum (xtimes (precision, 10), *digitp++ - '0');
+			}
+		    }
+
+		  switch (dp->conversion)
+		    {
+
+		    case 'd': case 'i': case 'u':
+# ifdef HAVE_LONG_LONG_INT
+		      if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
+					  * 0.30103 /* binary -> decimal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      else
+# endif
+		      if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned long) * CHAR_BIT
+					  * 0.30103 /* binary -> decimal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      else
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
+					  * 0.30103 /* binary -> decimal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      if (tmp_length < precision)
+			tmp_length = precision;
+		      /* Multiply by 2, as an estimate for FLAG_GROUP.  */
+		      tmp_length = xsum (tmp_length, tmp_length);
+		      /* Add 1, to account for a leading sign.  */
+		      tmp_length = xsum (tmp_length, 1);
+		      break;
+
+		    case 'o':
+# ifdef HAVE_LONG_LONG_INT
+		      if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
+					  * 0.333334 /* binary -> octal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      else
+# endif
+		      if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned long) * CHAR_BIT
+					  * 0.333334 /* binary -> octal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      else
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
+					  * 0.333334 /* binary -> octal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      if (tmp_length < precision)
+			tmp_length = precision;
+		      /* Add 1, to account for a leading sign.  */
+		      tmp_length = xsum (tmp_length, 1);
+		      break;
+
+		    case 'x': case 'X':
+# ifdef HAVE_LONG_LONG_INT
+		      if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
+					  * 0.25 /* binary -> hexadecimal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      else
+# endif
+		      if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned long) * CHAR_BIT
+					  * 0.25 /* binary -> hexadecimal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      else
+			tmp_length =
+			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
+					  * 0.25 /* binary -> hexadecimal */
+					 )
+			  + 1; /* turn floor into ceil */
+		      if (tmp_length < precision)
+			tmp_length = precision;
+		      /* Add 2, to account for a leading sign or alternate form.  */
+		      tmp_length = xsum (tmp_length, 2);
+		      break;
+
+		    case 'f': case 'F':
+# ifdef HAVE_LONG_DOUBLE
+		      if (type == TYPE_LONGDOUBLE)
+			tmp_length =
+			  (unsigned int) (LDBL_MAX_EXP
+					  * 0.30103 /* binary -> decimal */
+					  * 2 /* estimate for FLAG_GROUP */
+					 )
+			  + 1 /* turn floor into ceil */
+			  + 10; /* sign, decimal point etc. */
+		      else
+# endif
+			tmp_length =
+			  (unsigned int) (DBL_MAX_EXP
+					  * 0.30103 /* binary -> decimal */
+					  * 2 /* estimate for FLAG_GROUP */
+					 )
+			  + 1 /* turn floor into ceil */
+			  + 10; /* sign, decimal point etc. */
+		      tmp_length = xsum (tmp_length, precision);
+		      break;
+
+		    case 'e': case 'E': case 'g': case 'G':
+		    case 'a': case 'A':
+		      tmp_length =
+			12; /* sign, decimal point, exponent etc. */
+		      tmp_length = xsum (tmp_length, precision);
+		      break;
+
+		    case 'c':
+# if defined HAVE_WINT_T && !WIDE_CHAR_VERSION
+		      if (type == TYPE_WIDE_CHAR)
+			tmp_length = MB_CUR_MAX;
+		      else
+# endif
+			tmp_length = 1;
+		      break;
+
+		    case 's':
+# ifdef HAVE_WCHAR_T
+		      if (type == TYPE_WIDE_STRING)
+			{
+			  tmp_length =
+			    local_wcslen (a.arg[dp->arg_index].a.a_wide_string);
+
+#  if !WIDE_CHAR_VERSION
+			  tmp_length = xtimes (tmp_length, MB_CUR_MAX);
+#  endif
+			}
+		      else
+# endif
+			tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
+		      break;
+
+		    case 'p':
+		      tmp_length =
+			(unsigned int) (sizeof (void *) * CHAR_BIT
+					* 0.25 /* binary -> hexadecimal */
+				       )
+			  + 1 /* turn floor into ceil */
+			  + 2; /* account for leading 0x */
+		      break;
+
+		    default:
+		      abort ();
+		    }
+
+		  if (tmp_length < width)
+		    tmp_length = width;
+
+		  tmp_length = xsum (tmp_length, 1); /* account for trailing NUL */
+		}
+
+		if (tmp_length <= sizeof (tmpbuf) / sizeof (CHAR_T))
+		  tmp = tmpbuf;
+		else
+		  {
+		    size_t tmp_memsize = xtimes (tmp_length, sizeof (CHAR_T));
+
+		    if (size_overflow_p (tmp_memsize))
+		      /* Overflow, would lead to out of memory.  */
+		      goto out_of_memory;
+		    tmp = (CHAR_T *) malloc (tmp_memsize);
+		    if (tmp == NULL)
+		      /* Out of memory.  */
+		      goto out_of_memory;
+		  }
+#endif
+
+		/* Construct the format string for calling snprintf or
+		   sprintf.  */
+		p = buf;
+		*p++ = '%';
+		if (dp->flags & FLAG_GROUP)
+		  *p++ = '\'';
+		if (dp->flags & FLAG_LEFT)
+		  *p++ = '-';
+		if (dp->flags & FLAG_SHOWSIGN)
+		  *p++ = '+';
+		if (dp->flags & FLAG_SPACE)
+		  *p++ = ' ';
+		if (dp->flags & FLAG_ALT)
+		  *p++ = '#';
+		if (dp->flags & FLAG_ZERO)
+		  *p++ = '0';
+		if (dp->width_start != dp->width_end)
+		  {
+		    size_t n = dp->width_end - dp->width_start;
+		    memcpy (p, dp->width_start, n * sizeof (CHAR_T));
+		    p += n;
+		  }
+		if (dp->precision_start != dp->precision_end)
+		  {
+		    size_t n = dp->precision_end - dp->precision_start;
+		    memcpy (p, dp->precision_start, n * sizeof (CHAR_T));
+		    p += n;
+		  }
+
+		switch (type)
+		  {
+#ifdef HAVE_LONG_LONG_INT
+		  case TYPE_LONGLONGINT:
+		  case TYPE_ULONGLONGINT:
+		    *p++ = 'l';
+		    /*FALLTHROUGH*/
+#endif
+		  case TYPE_LONGINT:
+		  case TYPE_ULONGINT:
+#ifdef HAVE_WINT_T
+		  case TYPE_WIDE_CHAR:
+#endif
+#ifdef HAVE_WCHAR_T
+		  case TYPE_WIDE_STRING:
+#endif
+		    *p++ = 'l';
+		    break;
+#ifdef HAVE_LONG_DOUBLE
+		  case TYPE_LONGDOUBLE:
+		    *p++ = 'L';
+		    break;
+#endif
+		  default:
+		    break;
+		  }
+		*p = dp->conversion;
+#if USE_SNPRINTF
+		p[1] = '%';
+		p[2] = 'n';
+		p[3] = '\0';
+#else
+		p[1] = '\0';
+#endif
+
+		/* Construct the arguments for calling snprintf or sprintf.  */
+		prefix_count = 0;
+		if (dp->width_arg_index != ARG_NONE)
+		  {
+		    if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
+		      abort ();
+		    prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
+		  }
+		if (dp->precision_arg_index != ARG_NONE)
+		  {
+		    if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
+		      abort ();
+		    prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
+		  }
+
+#if USE_SNPRINTF
+		/* Prepare checking whether snprintf returns the count
+		   via %n.  */
+		ENSURE_ALLOCATION (xsum (length, 1));
+		result[length] = '\0';
+#endif
+
+		for (;;)
+		  {
+		    size_t maxlen;
+		    int count;
+		    int retcount;
+
+		    maxlen = allocated - length;
+		    count = -1;
+		    retcount = 0;
+
+#if USE_SNPRINTF
+# define SNPRINTF_BUF(arg) \
+		    switch (prefix_count)				    \
+		      {							    \
+		      case 0:						    \
+			retcount = SNPRINTF (result + length, maxlen, buf,  \
+					     arg, &count);		    \
+			break;						    \
+		      case 1:						    \
+			retcount = SNPRINTF (result + length, maxlen, buf,  \
+					     prefixes[0], arg, &count);	    \
+			break;						    \
+		      case 2:						    \
+			retcount = SNPRINTF (result + length, maxlen, buf,  \
+					     prefixes[0], prefixes[1], arg, \
+					     &count);			    \
+			break;						    \
+		      default:						    \
+			abort ();					    \
+		      }
+#else
+# define SNPRINTF_BUF(arg) \
+		    switch (prefix_count)				    \
+		      {							    \
+		      case 0:						    \
+			count = sprintf (tmp, buf, arg);		    \
+			break;						    \
+		      case 1:						    \
+			count = sprintf (tmp, buf, prefixes[0], arg);	    \
+			break;						    \
+		      case 2:						    \
+			count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
+					 arg);				    \
+			break;						    \
+		      default:						    \
+			abort ();					    \
+		      }
+#endif
+
+		    switch (type)
+		      {
+		      case TYPE_SCHAR:
+			{
+			  int arg = a.arg[dp->arg_index].a.a_schar;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_UCHAR:
+			{
+			  unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_SHORT:
+			{
+			  int arg = a.arg[dp->arg_index].a.a_short;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_USHORT:
+			{
+			  unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_INT:
+			{
+			  int arg = a.arg[dp->arg_index].a.a_int;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_UINT:
+			{
+			  unsigned int arg = a.arg[dp->arg_index].a.a_uint;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_LONGINT:
+			{
+			  long int arg = a.arg[dp->arg_index].a.a_longint;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_ULONGINT:
+			{
+			  unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#ifdef HAVE_LONG_LONG_INT
+		      case TYPE_LONGLONGINT:
+			{
+			  long long int arg = a.arg[dp->arg_index].a.a_longlongint;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      case TYPE_ULONGLONGINT:
+			{
+			  unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#endif
+		      case TYPE_DOUBLE:
+			{
+			  double arg = a.arg[dp->arg_index].a.a_double;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#ifdef HAVE_LONG_DOUBLE
+		      case TYPE_LONGDOUBLE:
+			{
+			  long double arg = a.arg[dp->arg_index].a.a_longdouble;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#endif
+		      case TYPE_CHAR:
+			{
+			  int arg = a.arg[dp->arg_index].a.a_char;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#ifdef HAVE_WINT_T
+		      case TYPE_WIDE_CHAR:
+			{
+			  wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#endif
+		      case TYPE_STRING:
+			{
+			  const char *arg = a.arg[dp->arg_index].a.a_string;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#ifdef HAVE_WCHAR_T
+		      case TYPE_WIDE_STRING:
+			{
+			  const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+#endif
+		      case TYPE_POINTER:
+			{
+			  void *arg = a.arg[dp->arg_index].a.a_pointer;
+			  SNPRINTF_BUF (arg);
+			}
+			break;
+		      default:
+			abort ();
+		      }
+
+#if USE_SNPRINTF
+		    /* Portability: Not all implementations of snprintf()
+		       are ISO C 99 compliant.  Determine the number of
+		       bytes that snprintf() has produced or would have
+		       produced.  */
+		    if (count >= 0)
+		      {
+			/* Verify that snprintf() has NUL-terminated its
+			   result.  */
+			if (count < maxlen && result[length + count] != '\0')
+			  abort ();
+			/* Portability hack.  */
+			if (retcount > count)
+			  count = retcount;
+		      }
+		    else
+		      {
+			/* snprintf() doesn't understand the '%n'
+			   directive.  */
+			if (p[1] != '\0')
+			  {
+			    /* Don't use the '%n' directive; instead, look
+			       at the snprintf() return value.  */
+			    p[1] = '\0';
+			    continue;
+			  }
+			else
+			  {
+			    /* Look at the snprintf() return value.  */
+			    if (retcount < 0)
+			      {
+				/* HP-UX 10.20 snprintf() is doubly deficient:
+				   It doesn't understand the '%n' directive,
+				   *and* it returns -1 (rather than the length
+				   that would have been required) when the
+				   buffer is too small.  */
+				size_t bigger_need =
+				  xsum (xtimes (allocated, 2), 12);
+				ENSURE_ALLOCATION (bigger_need);
+				continue;
+			      }
+			    else
+			      count = retcount;
+			  }
+		      }
+#endif
+
+		    /* Attempt to handle failure.  */
+		    if (count < 0)
+		      {
+			if (!(result == resultbuf || result == NULL))
+			  free (result);
+			if (buf_malloced != NULL)
+			  free (buf_malloced);
+			CLEANUP ();
+			errno = EINVAL;
+			return NULL;
+		      }
+
+#if !USE_SNPRINTF
+		    if (count >= tmp_length)
+		      /* tmp_length was incorrectly calculated - fix the
+			 code above!  */
+		      abort ();
+#endif
+
+		    /* Make room for the result.  */
+		    if (count >= maxlen)
+		      {
+			/* Need at least count bytes.  But allocate
+			   proportionally, to avoid looping eternally if
+			   snprintf() reports a too small count.  */
+			size_t n =
+			  xmax (xsum (length, count), xtimes (allocated, 2));
+
+			ENSURE_ALLOCATION (n);
+#if USE_SNPRINTF
+			continue;
+#endif
+		      }
+
+#if USE_SNPRINTF
+		    /* The snprintf() result did fit.  */
+#else
+		    /* Append the sprintf() result.  */
+		    memcpy (result + length, tmp, count * sizeof (CHAR_T));
+		    if (tmp != tmpbuf)
+		      free (tmp);
+#endif
+
+		    length += count;
+		    break;
+		  }
+	      }
+	  }
+      }
+
+    /* Add the final NUL.  */
+    ENSURE_ALLOCATION (xsum (length, 1));
+    result[length] = '\0';
+
+    if (result != resultbuf && length + 1 < allocated)
+      {
+	/* Shrink the allocated memory if possible.  */
+	CHAR_T *memory;
+
+	memory = (CHAR_T *) realloc (result, (length + 1) * sizeof (CHAR_T));
+	if (memory != NULL)
+	  result = memory;
+      }
+
+    if (buf_malloced != NULL)
+      free (buf_malloced);
+    CLEANUP ();
+    *lengthp = length;
+    /* Note that we can produce a big string of a length > INT_MAX.  POSIX
+       says that snprintf() fails with errno = EOVERFLOW in this case, but
+       that's only because snprintf() returns an 'int'.  This function does
+       not have this limitation.  */
+    return result;
+
+  out_of_memory:
+    if (!(result == resultbuf || result == NULL))
+      free (result);
+    if (buf_malloced != NULL)
+      free (buf_malloced);
+  out_of_memory_1:
+    CLEANUP ();
+    errno = ENOMEM;
+    return NULL;
+  }
+}
+
+#undef SNPRINTF
+#undef USE_SNPRINTF
+#undef PRINTF_PARSE
+#undef DIRECTIVES
+#undef DIRECTIVE
+#undef CHAR_T
+#undef VASNPRINTF
diff --git a/src/bin/m4/lib/vasnprintf.h b/src/bin/m4/lib/vasnprintf.h
new file mode 100644
index 0000000000..894008caec
--- /dev/null
+++ b/src/bin/m4/lib/vasnprintf.h
@@ -0,0 +1,77 @@
+/* vsprintf with automatic memory allocation.
+   Copyright (C) 2002-2004 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _VASNPRINTF_H
+#define _VASNPRINTF_H
+
+/* Get va_list.  */
+#include <stdarg.h>
+
+/* Get size_t.  */
+#include <stddef.h>
+
+#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
+#  define __attribute__(Spec) /* empty */
+# endif
+/* The __-protected variants of `format' and `printf' attributes
+   are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
+#  define __format__ format
+#  define __printf__ printf
+# endif
+#endif
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* Write formatted output to a string dynamically allocated with malloc().
+   You can pass a preallocated buffer for the result in RESULTBUF and its
+   size in *LENGTHP; otherwise you pass RESULTBUF = NULL.
+   If successful, return the address of the string (this may be = RESULTBUF
+   if no dynamic memory allocation was necessary) and set *LENGTHP to the
+   number of resulting bytes, excluding the trailing NUL.  Upon error, set
+   errno and return NULL.
+
+   When dynamic memory allocation occurs, the preallocated buffer is left
+   alone (with possibly modified contents).  This makes it possible to use
+   a statically allocated or stack-allocated buffer, like this:
+
+          char buf[100];
+          size_t len = sizeof (buf);
+          char *output = vasnprintf (buf, &len, format, args);
+          if (output == NULL)
+            ... error handling ...;
+          else
+            {
+              ... use the output string ...;
+              if (output != buf)
+                free (output);
+            }
+  */
+extern char * asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...)
+       __attribute__ ((__format__ (__printf__, 3, 4)));
+extern char * vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args)
+       __attribute__ ((__format__ (__printf__, 3, 0)));
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* _VASNPRINTF_H */
diff --git a/src/bin/m4/lib/vasprintf.c b/src/bin/m4/lib/vasprintf.c
new file mode 100644
index 0000000000..824707345a
--- /dev/null
+++ b/src/bin/m4/lib/vasprintf.c
@@ -0,0 +1,52 @@
+/* Formatted output to strings.
+   Copyright (C) 1999, 2002, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "vasprintf.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+
+#include "vasnprintf.h"
+
+/* Some systems, like OSF/1 4.0 and Woe32, don't have EOVERFLOW.  */
+#ifndef EOVERFLOW
+# define EOVERFLOW E2BIG
+#endif
+
+int
+vasprintf (char **resultp, const char *format, va_list args)
+{
+  size_t length;
+  char *result = vasnprintf (NULL, &length, format, args);
+  if (result == NULL)
+    return -1;
+
+  if (length > INT_MAX)
+    {
+      free (result);
+      errno = EOVERFLOW;
+      return -1;
+    }
+
+  *resultp = result;
+  /* Return the number of resulting bytes, excluding the trailing NUL.  */
+  return length;
+}
diff --git a/src/bin/m4/lib/vasprintf.h b/src/bin/m4/lib/vasprintf.h
new file mode 100644
index 0000000000..ab5515ce7f
--- /dev/null
+++ b/src/bin/m4/lib/vasprintf.h
@@ -0,0 +1,63 @@
+/* vsprintf with automatic memory allocation.
+   Copyright (C) 2002-2003 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _VASPRINTF_H
+#define _VASPRINTF_H
+
+#if HAVE_VASPRINTF
+
+/* Get asprintf(), vasprintf() declarations.  */
+#include <stdio.h>
+
+#else
+
+/* Get va_list.  */
+#include <stdarg.h>
+
+#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
+#  define __attribute__(Spec) /* empty */
+# endif
+/* The __-protected variants of `format' and `printf' attributes
+   are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
+#  define __format__ format
+#  define __printf__ printf
+# endif
+#endif
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* Write formatted output to a string dynamically allocated with malloc().
+   If the memory allocation succeeds, store the address of the string in
+   *RESULT and return the number of resulting bytes, excluding the trailing
+   NUL.  Upon memory allocation error, or some other error, return -1.  */
+extern int asprintf (char **result, const char *format, ...)
+       __attribute__ ((__format__ (__printf__, 2, 3)));
+extern int vasprintf (char **result, const char *format, va_list args)
+       __attribute__ ((__format__ (__printf__, 2, 0)));
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif
+
+#endif /* _VASPRINTF_H */
diff --git a/src/bin/m4/lib/verify.h b/src/bin/m4/lib/verify.h
new file mode 100644
index 0000000000..d603b17379
--- /dev/null
+++ b/src/bin/m4/lib/verify.h
@@ -0,0 +1,141 @@
+/* Compile-time assert-like macros.
+
+   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert, Bruno Haible, and Jim Meyering.  */
+
+#ifndef VERIFY_H
+# define VERIFY_H 1
+
+/* Each of these macros verifies that its argument R is nonzero.  To
+   be portable, R should be an integer constant expression.  Unlike
+   assert (R), there is no run-time overhead.
+
+   There are two macros, since no single macro can be used in all
+   contexts in C.  verify_true (R) is for scalar contexts, including
+   integer constant expression contexts.  verify (R) is for declaration
+   contexts, e.g., the top level.
+
+   Symbols ending in "__" are private to this header.
+
+   The code below uses several ideas.
+
+   * The first step is ((R) ? 1 : -1).  Given an expression R, of
+     integral or boolean or floating-point type, this yields an
+     expression of integral type, whose value is later verified to be
+     constant and nonnegative.
+
+   * Next this expression W is wrapped in a type
+     struct verify_type__ { unsigned int verify_error_if_negative_size__: W; }.
+     If W is negative, this yields a compile-time error.  No compiler can
+     deal with a bit-field of negative size.
+
+     One might think that an array size check would have the same
+     effect, that is, that the type struct { unsigned int dummy[W]; }
+     would work as well.  However, inside a function, some compilers
+     (such as C++ compilers and GNU C) allow local parameters and
+     variables inside array size expressions.  With these compilers,
+     an array size check would not properly diagnose this misuse of
+     the verify macro:
+
+       void function (int n) { verify (n < 0); }
+
+   * For the verify macro, the struct verify_type__ will need to
+     somehow be embedded into a declaration.  To be portable, this
+     declaration must declare an object, a constant, a function, or a
+     typedef name.  If the declared entity uses the type directly,
+     such as in
+
+       struct dummy {...};
+       typedef struct {...} dummy;
+       extern struct {...} *dummy;
+       extern void dummy (struct {...} *);
+       extern struct {...} *dummy (void);
+
+     two uses of the verify macro would yield colliding declarations
+     if the entity names are not disambiguated.  A workaround is to
+     attach the current line number to the entity name:
+
+       #define GL_CONCAT0(x, y) x##y
+       #define GL_CONCAT(x, y) GL_CONCAT0 (x, y)
+       extern struct {...} * GL_CONCAT(dummy,__LINE__);
+
+     But this has the problem that two invocations of verify from
+     within the same macro would collide, since the __LINE__ value
+     would be the same for both invocations.
+
+     A solution is to use the sizeof operator.  It yields a number,
+     getting rid of the identity of the type.  Declarations like
+
+       extern int dummy [sizeof (struct {...})];
+       extern void dummy (int [sizeof (struct {...})]);
+       extern int (*dummy (void)) [sizeof (struct {...})];
+
+     can be repeated.
+
+   * Should the implementation use a named struct or an unnamed struct?
+     Which of the following alternatives can be used?
+
+       extern int dummy [sizeof (struct {...})];
+       extern int dummy [sizeof (struct verify_type__ {...})];
+       extern void dummy (int [sizeof (struct {...})]);
+       extern void dummy (int [sizeof (struct verify_type__ {...})]);
+       extern int (*dummy (void)) [sizeof (struct {...})];
+       extern int (*dummy (void)) [sizeof (struct verify_type__ {...})];
+
+     In the second and sixth case, the struct type is exported to the
+     outer scope; two such declarations therefore collide.  GCC warns
+     about the first, third, and fourth cases.  So the only remaining
+     possibility is the fifth case:
+
+       extern int (*dummy (void)) [sizeof (struct {...})];
+
+   * This implementation exploits the fact that GCC does not warn about
+     the last declaration mentioned above.  If a future version of GCC
+     introduces a warning for this, the problem could be worked around
+     by using code specialized to GCC, e.g.,:
+
+       #if 4 <= __GNUC__
+       # define verify(R) \
+	   extern int (* verify_function__ (void)) \
+		      [__builtin_constant_p (R) && (R) ? 1 : -1]
+       #endif
+
+   * In C++, any struct definition inside sizeof is invalid.
+     Use a template type to work around the problem.  */
+
+
+/* Verify requirement R at compile-time, as an integer constant expression.
+   Return 1.  */
+
+# ifdef __cplusplus
+template <int w>
+  struct verify_type__ { unsigned int verify_error_if_negative_size__: w; };
+#  define verify_true(R) \
+     (!!sizeof (verify_type__<(R) ? 1 : -1>))
+# else
+#  define verify_true(R) \
+     (!!sizeof \
+      (struct { unsigned int verify_error_if_negative_size__: (R) ? 1 : -1; }))
+# endif
+
+/* Verify requirement R at compile-time, as a declaration without a
+   trailing ';'.  */
+
+# define verify(R) extern int (* verify_function__ (void)) [verify_true (R)]
+
+#endif
diff --git a/src/bin/m4/lib/verror.c b/src/bin/m4/lib/verror.c
new file mode 100644
index 0000000000..531e4edb5f
--- /dev/null
+++ b/src/bin/m4/lib/verror.c
@@ -0,0 +1,77 @@
+/* va_list error handler for noninteractive utilities
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Eric Blake.  */
+
+#include <config.h>
+
+#include "verror.h"
+#include "xvasprintf.h"
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
+#if ENABLE_NLS
+# include "gettext.h"
+#endif
+
+#ifndef _
+# define _(String) String
+#endif
+
+/* Print a message with `vfprintf (stderr, FORMAT, ARGS)';
+   if ERRNUM is nonzero, follow it with ": " and strerror (ERRNUM).
+   If STATUS is nonzero, terminate the program with `exit (STATUS)'.
+   Use the globals error_print_progname and error_message_count similarly
+   to error().  */
+void
+verror (int status, int errnum, const char *format, va_list args)
+{
+  verror_at_line (status, errnum, NULL, 0, format, args);
+}
+
+/* Print a message with `vfprintf (stderr, FORMAT, ARGS)';
+   if ERRNUM is nonzero, follow it with ": " and strerror (ERRNUM).
+   If STATUS is nonzero, terminate the program with `exit (STATUS)'.
+   If FNAME is not NULL, prepend the message with `FNAME:LINENO:'.
+   Use the globals error_print_progname, error_message_count, and
+   error_one_per_line similarly to error_at_line().  */
+void
+verror_at_line (int status, int errnum, const char *file,
+                unsigned int line_number, const char *format, va_list args)
+{
+  char *message = xvasprintf (format, args);
+  if (message)
+    {
+      /* Until http://sourceware.org/bugzilla/show_bug.cgi?id=2997 is fixed,
+	 glibc violates GNU Coding Standards when the file argument to
+	 error_at_line is NULL.  */
+      if (file)
+        error_at_line (status, errnum, file, line_number, "%s", message);
+      else
+        error (status, errnum, "%s", message);
+    }
+  else
+    {
+      /* EOVERFLOW, EINVAL, and EILSEQ from xvasprintf are signs of
+         serious programmer errors.  */
+      error (0, errno, _("unable to display error message"));
+      abort ();
+    }
+  free (message);
+}
diff --git a/src/bin/m4/lib/verror.h b/src/bin/m4/lib/verror.h
new file mode 100644
index 0000000000..625ef102ee
--- /dev/null
+++ b/src/bin/m4/lib/verror.h
@@ -0,0 +1,54 @@
+/* Declaration for va_list error-reporting function
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _VERROR_H
+#define _VERROR_H 1
+
+#include "error.h"
+#include <stdarg.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* Print a message with `vfprintf (stderr, FORMAT, ARGS)';
+   if ERRNUM is nonzero, follow it with ": " and strerror (ERRNUM).
+   If STATUS is nonzero, terminate the program with `exit (STATUS)'.
+   Use the globals error_print_progname and error_message_count similarly
+   to error().  */
+
+extern void verror (int __status, int __errnum, const char *__format,
+                    va_list __args)
+     __attribute__ ((__format__ (__printf__, 3, 0)));
+
+/* Print a message with `vfprintf (stderr, FORMAT, ARGS)';
+   if ERRNUM is nonzero, follow it with ": " and strerror (ERRNUM).
+   If STATUS is nonzero, terminate the program with `exit (STATUS)'.
+   If FNAME is not NULL, prepend the message with `FNAME:LINENO:'.
+   Use the globals error_print_progname, error_message_count, and
+   error_one_per_line similarly to error_at_line().  */
+
+extern void verror_at_line (int __status, int __errnum, const char *__fname,
+                            unsigned int __lineno, const char *__format,
+                            va_list __args)
+     __attribute__ ((__format__ (__printf__, 5, 0)));
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* verror.h */
diff --git a/src/bin/m4/lib/wcwidth.h b/src/bin/m4/lib/wcwidth.h
new file mode 100644
index 0000000000..83da8fb0fb
--- /dev/null
+++ b/src/bin/m4/lib/wcwidth.h
@@ -0,0 +1,81 @@
+/* Determine the number of screen columns needed for a character.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _gl_WCWIDTH_H
+#define _gl_WCWIDTH_H
+
+#if HAVE_WCHAR_T
+
+/* Get wcwidth if available, along with wchar_t.  */
+# if HAVE_WCHAR_H
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
+   <wchar.h>.  */
+#  include <stdio.h>
+#  include <time.h>
+#  include <wchar.h>
+# endif
+
+/* Get iswprint.  */
+# if HAVE_WCTYPE_H
+#  include <wctype.h>
+# endif
+# if !defined iswprint && !HAVE_ISWPRINT
+static inline int
+#  if HAVE_WINT_T
+iswprint (wint_t wc)
+#  else
+iswprint (int wc)
+#  endif
+{
+  return (wc >= 0 && wc < 128
+	  ? wc >= ' ' && wc <= '~'
+	  : 1);
+}
+#  define iswprint iswprint
+# endif
+
+# ifndef HAVE_DECL_WCWIDTH
+"this configure-time declaration test was not run"
+# endif
+# ifndef wcwidth
+#  if !HAVE_WCWIDTH
+
+/* wcwidth doesn't exist, so assume all printable characters have
+   width 1.  */
+static inline int
+wcwidth (wchar_t wc)
+{
+  return wc == 0 ? 0 : iswprint (wc) ? 1 : -1;
+}
+
+#  elif !HAVE_DECL_WCWIDTH
+
+/* wcwidth exists but is not declared.  */
+extern
+#   ifdef __cplusplus
+"C"
+#   endif
+int wcwidth (int /* actually wchar_t */);
+
+#  endif
+# endif
+
+#endif /* HAVE_WCHAR_H */
+
+#endif /* _gl_WCWIDTH_H */
diff --git a/src/bin/m4/lib/xalloc-die.c b/src/bin/m4/lib/xalloc-die.c
new file mode 100644
index 0000000000..090f060df7
--- /dev/null
+++ b/src/bin/m4/lib/xalloc-die.c
@@ -0,0 +1,42 @@
+/* Report a memory allocation failure and exit.
+
+   Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#include "xalloc.h"
+
+#include <stdlib.h>
+
+#include "error.h"
+#include "exitfail.h"
+
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
+void
+xalloc_die (void)
+{
+  error (exit_failure, 0, "%s", _("memory exhausted"));
+
+  /* The `noreturn' cannot be given to error, since it may return if
+     its first argument is 0.  To help compilers understand the
+     xalloc_die does not return, call abort.  Also, the abort is a
+     safety feature if exit_failure is 0 (which shouldn't happen).  */
+  abort ();
+}
diff --git a/src/bin/m4/lib/xalloc.h b/src/bin/m4/lib/xalloc.h
new file mode 100644
index 0000000000..17ab514218
--- /dev/null
+++ b/src/bin/m4/lib/xalloc.h
@@ -0,0 +1,267 @@
+/* xalloc.h -- malloc with out-of-memory checking
+
+   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+   1999, 2000, 2003, 2004, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef XALLOC_H_
+# define XALLOC_H_
+
+# include <stddef.h>
+
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+
+# ifndef __attribute__
+#  if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
+#   define __attribute__(x)
+#  endif
+# endif
+
+# ifndef ATTRIBUTE_NORETURN
+#  define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
+# endif
+
+/* This function is always triggered when memory is exhausted.
+   It must be defined by the application, either explicitly
+   or by using gnulib's xalloc-die module.  This is the
+   function to call when one wants the program to die because of a
+   memory allocation failure.  */
+extern void xalloc_die (void) ATTRIBUTE_NORETURN;
+
+void *xmalloc (size_t s);
+void *xzalloc (size_t s);
+void *xcalloc (size_t n, size_t s);
+void *xrealloc (void *p, size_t s);
+void *x2realloc (void *p, size_t *pn);
+void *xmemdup (void const *p, size_t s);
+char *xstrdup (char const *str);
+
+/* Return 1 if an array of N objects, each of size S, cannot exist due
+   to size arithmetic overflow.  S must be positive and N must be
+   nonnegative.  This is a macro, not an inline function, so that it
+   works correctly even when SIZE_MAX < N.
+
+   By gnulib convention, SIZE_MAX represents overflow in size
+   calculations, so the conservative dividend to use here is
+   SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
+   However, malloc (SIZE_MAX) fails on all known hosts where
+   sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
+   exactly-SIZE_MAX allocations on such hosts; this avoids a test and
+   branch when S is known to be 1.  */
+# define xalloc_oversized(n, s) \
+    ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
+
+
+/* In the following macros, T must be an elementary or structure/union or
+   typedef'ed type, or a pointer to such a type.  To apply one of the
+   following macros to a function pointer or array type, you need to typedef
+   it first and use the typedef name.  */
+
+/* Allocate an object of type T dynamically, with error checking.  */
+/* extern t *XMALLOC (typename t); */
+# define XMALLOC(t) ((t *) xmalloc (sizeof (t)))
+
+/* Allocate memory for N elements of type T, with error checking.  */
+/* extern t *XNMALLOC (size_t n, typename t); */
+# define XNMALLOC(n, t) \
+    ((t *) (sizeof (t) == 1 ? xmalloc (n) : xnmalloc (n, sizeof (t))))
+
+/* Allocate an object of type T dynamically, with error checking,
+   and zero it.  */
+/* extern t *XZALLOC (typename t); */
+# define XZALLOC(t) ((t *) xzalloc (sizeof (t)))
+
+/* Allocate memory for N elements of type T, with error checking,
+   and zero it.  */
+/* extern t *XCALLOC (size_t n, typename t); */
+# define XCALLOC(n, t) \
+    ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t))))
+
+
+# if HAVE_INLINE
+#  define static_inline static inline
+# else
+   void *xnmalloc (size_t n, size_t s);
+   void *xnrealloc (void *p, size_t n, size_t s);
+   void *x2nrealloc (void *p, size_t *pn, size_t s);
+   char *xcharalloc (size_t n);
+# endif
+
+# ifdef static_inline
+
+/* Allocate an array of N objects, each with S bytes of memory,
+   dynamically, with error checking.  S must be nonzero.  */
+
+static_inline void *
+xnmalloc (size_t n, size_t s)
+{
+  if (xalloc_oversized (n, s))
+    xalloc_die ();
+  return xmalloc (n * s);
+}
+
+/* Change the size of an allocated block of memory P to an array of N
+   objects each of S bytes, with error checking.  S must be nonzero.  */
+
+static_inline void *
+xnrealloc (void *p, size_t n, size_t s)
+{
+  if (xalloc_oversized (n, s))
+    xalloc_die ();
+  return xrealloc (p, n * s);
+}
+
+/* If P is null, allocate a block of at least *PN such objects;
+   otherwise, reallocate P so that it contains more than *PN objects
+   each of S bytes.  *PN must be nonzero unless P is null, and S must
+   be nonzero.  Set *PN to the new number of objects, and return the
+   pointer to the new block.  *PN is never set to zero, and the
+   returned pointer is never null.
+
+   Repeated reallocations are guaranteed to make progress, either by
+   allocating an initial block with a nonzero size, or by allocating a
+   larger block.
+
+   In the following implementation, nonzero sizes are doubled so that
+   repeated reallocations have O(N log N) overall cost rather than
+   O(N**2) cost, but the specification for this function does not
+   guarantee that sizes are doubled.
+
+   Here is an example of use:
+
+     int *p = NULL;
+     size_t used = 0;
+     size_t allocated = 0;
+
+     void
+     append_int (int value)
+       {
+	 if (used == allocated)
+	   p = x2nrealloc (p, &allocated, sizeof *p);
+	 p[used++] = value;
+       }
+
+   This causes x2nrealloc to allocate a block of some nonzero size the
+   first time it is called.
+
+   To have finer-grained control over the initial size, set *PN to a
+   nonzero value before calling this function with P == NULL.  For
+   example:
+
+     int *p = NULL;
+     size_t used = 0;
+     size_t allocated = 0;
+     size_t allocated1 = 1000;
+
+     void
+     append_int (int value)
+       {
+	 if (used == allocated)
+	   {
+	     p = x2nrealloc (p, &allocated1, sizeof *p);
+	     allocated = allocated1;
+	   }
+	 p[used++] = value;
+       }
+
+   */
+
+static_inline void *
+x2nrealloc (void *p, size_t *pn, size_t s)
+{
+  size_t n = *pn;
+
+  if (! p)
+    {
+      if (! n)
+	{
+	  /* The approximate size to use for initial small allocation
+	     requests, when the invoking code specifies an old size of
+	     zero.  64 bytes is the largest "small" request for the
+	     GNU C library malloc.  */
+	  enum { DEFAULT_MXFAST = 64 };
+
+	  n = DEFAULT_MXFAST / s;
+	  n += !n;
+	}
+    }
+  else
+    {
+      if (((size_t) -1) / 2 / s < n)
+	xalloc_die ();
+      n *= 2;
+    }
+
+  *pn = n;
+  return xrealloc (p, n * s);
+}
+
+/* Return a pointer to a new buffer of N bytes.  This is like xmalloc,
+   except it returns char *.  */
+
+static_inline char *
+xcharalloc (size_t n)
+{
+  return XNMALLOC (n, char);
+}
+
+# endif
+
+# ifdef __cplusplus
+}
+
+/* C++ does not allow conversions from void * to other pointer types
+   without a cast.  Use templates to work around the problem when
+   possible.  */
+
+template <typename T> inline T *
+xrealloc (T *p, size_t s)
+{
+  return (T *) xrealloc ((void *) p, s);
+}
+
+template <typename T> inline T *
+xnrealloc (T *p, size_t n, size_t s)
+{
+  return (T *) xnrealloc ((void *) p, n, s);
+}
+
+template <typename T> inline T *
+x2realloc (T *p, size_t *pn)
+{
+  return (T *) x2realloc ((void *) p, pn);
+}
+
+template <typename T> inline T *
+x2nrealloc (T *p, size_t *pn, size_t s)
+{
+  return (T *) x2nrealloc ((void *) p, pn, s);
+}
+
+template <typename T> inline T *
+xmemdup (T const *p, size_t s)
+{
+  return (T *) xmemdup ((void const *) p, s);
+}
+
+# endif
+
+
+#endif /* !XALLOC_H_ */
diff --git a/src/bin/m4/lib/xallocsa.c b/src/bin/m4/lib/xallocsa.c
new file mode 100644
index 0000000000..c69128a365
--- /dev/null
+++ b/src/bin/m4/lib/xallocsa.c
@@ -0,0 +1,35 @@
+/* Safe automatic memory allocation with out of memory checking.
+   Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "xallocsa.h"
+
+#include "xalloc.h"
+
+void *
+xmallocsa (size_t n)
+{
+  void *p;
+
+  p = mallocsa (n);
+  if (p == NULL)
+    xalloc_die ();
+  return p;
+}
diff --git a/src/bin/m4/lib/xallocsa.h b/src/bin/m4/lib/xallocsa.h
new file mode 100644
index 0000000000..baede95775
--- /dev/null
+++ b/src/bin/m4/lib/xallocsa.h
@@ -0,0 +1,54 @@
+/* Safe automatic memory allocation with out of memory checking.
+   Copyright (C) 2003, 2005 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _XALLOCSA_H
+#define _XALLOCSA_H
+
+#include "allocsa.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* xallocsa(N) is a checking safe variant of alloca(N).  It allocates N bytes
+   of memory allocated on the stack, that must be freed using freesa() before
+   the function returns.  Upon failure, it exits with an error message.  */
+#if HAVE_ALLOCA
+# define xallocsa(N) \
+  ((N) < 4032 - sa_increment					    \
+   ? (void *) ((char *) alloca ((N) + sa_increment) + sa_increment) \
+   : xmallocsa (N))
+extern void * xmallocsa (size_t n);
+#else
+# define xallocsa(N) \
+  xmalloc (N)
+#endif
+
+/* Maybe we should also define a variant
+    xnallocsa (size_t n, size_t s) - behaves like xallocsa (n * s)
+   If this would be useful in your application. please speak up.  */
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* _XALLOCSA_H */
diff --git a/src/bin/m4/lib/xasprintf.c b/src/bin/m4/lib/xasprintf.c
new file mode 100644
index 0000000000..cf1b8a5ee4
--- /dev/null
+++ b/src/bin/m4/lib/xasprintf.c
@@ -0,0 +1,34 @@
+/* vasprintf and asprintf with out-of-memory checking.
+   Copyright (C) 1999, 2002-2004, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "xvasprintf.h"
+
+char *
+xasprintf (const char *format, ...)
+{
+  va_list args;
+  char *result;
+
+  va_start (args, format);
+  result = xvasprintf (format, args);
+  va_end (args);
+
+  return result;
+}
diff --git a/src/bin/m4/lib/xmalloc.c b/src/bin/m4/lib/xmalloc.c
new file mode 100644
index 0000000000..318e0ddb5a
--- /dev/null
+++ b/src/bin/m4/lib/xmalloc.c
@@ -0,0 +1,123 @@
+/* xmalloc.c -- malloc with out of memory checking
+
+   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+   1999, 2000, 2002, 2003, 2004, 2005, 2006 Free Software Foundation,
+   Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#if ! HAVE_INLINE
+# define static_inline
+#endif
+#include "xalloc.h"
+#undef static_inline
+
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+/* 1 if calloc is known to be compatible with GNU calloc.  This
+   matters if we are not also using the calloc module, which defines
+   HAVE_CALLOC and supports the GNU API even on non-GNU platforms.  */
+#if defined HAVE_CALLOC || defined __GLIBC__
+enum { HAVE_GNU_CALLOC = 1 };
+#else
+enum { HAVE_GNU_CALLOC = 0 };
+#endif
+
+/* Allocate N bytes of memory dynamically, with error checking.  */
+
+void *
+xmalloc (size_t n)
+{
+  void *p = malloc (n);
+  if (!p && n != 0)
+    xalloc_die ();
+  return p;
+}
+
+/* Change the size of an allocated block of memory P to N bytes,
+   with error checking.  */
+
+void *
+xrealloc (void *p, size_t n)
+{
+  p = realloc (p, n);
+  if (!p && n != 0)
+    xalloc_die ();
+  return p;
+}
+
+/* If P is null, allocate a block of at least *PN bytes; otherwise,
+   reallocate P so that it contains more than *PN bytes.  *PN must be
+   nonzero unless P is null.  Set *PN to the new block's size, and
+   return the pointer to the new block.  *PN is never set to zero, and
+   the returned pointer is never null.  */
+
+void *
+x2realloc (void *p, size_t *pn)
+{
+  return x2nrealloc (p, pn, 1);
+}
+
+/* Allocate S bytes of zeroed memory dynamically, with error checking.
+   There's no need for xnzalloc (N, S), since it would be equivalent
+   to xcalloc (N, S).  */
+
+void *
+xzalloc (size_t s)
+{
+  return memset (xmalloc (s), 0, s);
+}
+
+/* Allocate zeroed memory for N elements of S bytes, with error
+   checking.  S must be nonzero.  */
+
+void *
+xcalloc (size_t n, size_t s)
+{
+  void *p;
+  /* Test for overflow, since some calloc implementations don't have
+     proper overflow checks.  But omit overflow and size-zero tests if
+     HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
+     returns NULL if successful.  */
+  if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s))
+      || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))
+    xalloc_die ();
+  return p;
+}
+
+/* Clone an object P of size S, with error checking.  There's no need
+   for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any
+   need for an arithmetic overflow check.  */
+
+void *
+xmemdup (void const *p, size_t s)
+{
+  return memcpy (xmalloc (s), p, s);
+}
+
+/* Clone STRING.  */
+
+char *
+xstrdup (char const *string)
+{
+  return xmemdup (string, strlen (string) + 1);
+}
diff --git a/src/bin/m4/lib/xsize.h b/src/bin/m4/lib/xsize.h
new file mode 100644
index 0000000000..341fb16ca7
--- /dev/null
+++ b/src/bin/m4/lib/xsize.h
@@ -0,0 +1,108 @@
+/* xsize.h -- Checked size_t computations.
+
+   Copyright (C) 2003 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _XSIZE_H
+#define _XSIZE_H
+
+/* Get size_t.  */
+#include <stddef.h>
+
+/* Get SIZE_MAX.  */
+#include <limits.h>
+#if HAVE_STDINT_H
+# include <stdint.h>
+#endif
+
+/* The size of memory objects is often computed through expressions of
+   type size_t. Example:
+      void* p = malloc (header_size + n * element_size).
+   These computations can lead to overflow.  When this happens, malloc()
+   returns a piece of memory that is way too small, and the program then
+   crashes while attempting to fill the memory.
+   To avoid this, the functions and macros in this file check for overflow.
+   The convention is that SIZE_MAX represents overflow.
+   malloc (SIZE_MAX) is not guaranteed to fail -- think of a malloc
+   implementation that uses mmap --, it's recommended to use size_overflow_p()
+   or size_in_bounds_p() before invoking malloc().
+   The example thus becomes:
+      size_t size = xsum (header_size, xtimes (n, element_size));
+      void *p = (size_in_bounds_p (size) ? malloc (size) : NULL);
+*/
+
+/* Convert an arbitrary value >= 0 to type size_t.  */
+#define xcast_size_t(N) \
+  ((N) <= SIZE_MAX ? (size_t) (N) : SIZE_MAX)
+
+/* Sum of two sizes, with overflow check.  */
+static inline size_t
+#if __GNUC__ >= 3
+__attribute__ ((__pure__))
+#endif
+xsum (size_t size1, size_t size2)
+{
+  size_t sum = size1 + size2;
+  return (sum >= size1 ? sum : SIZE_MAX);
+}
+
+/* Sum of three sizes, with overflow check.  */
+static inline size_t
+#if __GNUC__ >= 3
+__attribute__ ((__pure__))
+#endif
+xsum3 (size_t size1, size_t size2, size_t size3)
+{
+  return xsum (xsum (size1, size2), size3);
+}
+
+/* Sum of four sizes, with overflow check.  */
+static inline size_t
+#if __GNUC__ >= 3
+__attribute__ ((__pure__))
+#endif
+xsum4 (size_t size1, size_t size2, size_t size3, size_t size4)
+{
+  return xsum (xsum (xsum (size1, size2), size3), size4);
+}
+
+/* Maximum of two sizes, with overflow check.  */
+static inline size_t
+#if __GNUC__ >= 3
+__attribute__ ((__pure__))
+#endif
+xmax (size_t size1, size_t size2)
+{
+  /* No explicit check is needed here, because for any n:
+     max (SIZE_MAX, n) == SIZE_MAX and max (n, SIZE_MAX) == SIZE_MAX.  */
+  return (size1 >= size2 ? size1 : size2);
+}
+
+/* Multiplication of a count with an element size, with overflow check.
+   The count must be >= 0 and the element size must be > 0.
+   This is a macro, not an inline function, so that it works correctly even
+   when N is of a wider tupe and N > SIZE_MAX.  */
+#define xtimes(N, ELSIZE) \
+  ((N) <= SIZE_MAX / (ELSIZE) ? (size_t) (N) * (ELSIZE) : SIZE_MAX)
+
+/* Check for overflow.  */
+#define size_overflow_p(SIZE) \
+  ((SIZE) == SIZE_MAX)
+/* Check against overflow.  */
+#define size_in_bounds_p(SIZE) \
+  ((SIZE) != SIZE_MAX)
+
+#endif /* _XSIZE_H */
diff --git a/src/bin/m4/lib/xvasprintf.c b/src/bin/m4/lib/xvasprintf.c
new file mode 100644
index 0000000000..b68442764d
--- /dev/null
+++ b/src/bin/m4/lib/xvasprintf.c
@@ -0,0 +1,116 @@
+/* vasprintf and asprintf with out-of-memory checking.
+   Copyright (C) 1999, 2002-2004, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "xvasprintf.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <string.h>
+
+#include "vasprintf.h"
+#include "xalloc.h"
+
+/* Checked size_t computations.  */
+#include "xsize.h"
+
+/* Some systems, like OSF/1 4.0 and Woe32, don't have EOVERFLOW.  */
+#ifndef EOVERFLOW
+# define EOVERFLOW E2BIG
+#endif
+
+static inline char *
+xstrcat (size_t argcount, va_list args)
+{
+  char *result;
+  va_list ap;
+  size_t totalsize;
+  size_t i;
+  char *p;
+
+  /* Determine the total size.  */
+  totalsize = 0;
+  va_copy (ap, args);
+  for (i = argcount; i > 0; i--)
+    {
+      const char *next = va_arg (ap, const char *);
+      totalsize = xsum (totalsize, strlen (next));
+    }
+  va_end (ap);
+
+  /* Test for overflow in the summing pass above or in (totalsize + 1) below.
+     Also, don't return a string longer than INT_MAX, for consistency with
+     vasprintf().  */
+  if (totalsize == SIZE_MAX || totalsize > INT_MAX)
+    {
+      errno = EOVERFLOW;
+      return NULL;
+    }
+
+  /* Allocate and fill the result string.  */
+  result = XNMALLOC (totalsize + 1, char);
+  p = result;
+  for (i = argcount; i > 0; i--)
+    {
+      const char *next = va_arg (args, const char *);
+      size_t len = strlen (next);
+      memcpy (p, next, len);
+      p += len;
+    }
+  *p = '\0';
+
+  return result;
+}
+
+char *
+xvasprintf (const char *format, va_list args)
+{
+  char *result;
+
+  /* Recognize the special case format = "%s...%s".  It is a frequently used
+     idiom for string concatenation and needs to be fast.  We don't want to
+     have a separate function xstrcat() for this purpose.  */
+  {
+    size_t argcount = 0;
+    const char *f;
+
+    for (f = format;;)
+      {
+	if (*f == '\0')
+	  /* Recognized the special case of string concatenation.  */
+	  return xstrcat (argcount, args);
+	if (*f != '%')
+	  break;
+	f++;
+	if (*f != 's')
+	  break;
+	f++;
+	argcount++;
+      }
+  }
+
+  if (vasprintf (&result, format, args) < 0)
+    {
+      if (errno == ENOMEM)
+	xalloc_die ();
+      return NULL;
+    }
+
+  return result;
+}
diff --git a/src/bin/m4/lib/xvasprintf.h b/src/bin/m4/lib/xvasprintf.h
new file mode 100644
index 0000000000..de55a9f0c8
--- /dev/null
+++ b/src/bin/m4/lib/xvasprintf.h
@@ -0,0 +1,57 @@
+/* vasprintf and asprintf with out-of-memory checking.
+   Copyright (C) 2002-2004, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _XVASPRINTF_H
+#define _XVASPRINTF_H
+
+/* Get va_list.  */
+#include <stdarg.h>
+
+#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
+#  define __attribute__(Spec) /* empty */
+# endif
+/* The __-protected variants of `format' and `printf' attributes
+   are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
+#  define __format__ format
+#  define __printf__ printf
+# endif
+#endif
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* Write formatted output to a string dynamically allocated with malloc(),
+   and return it.  Upon [ENOMEM] memory allocation error, call xalloc_die.
+   On some other error
+     - [EOVERFLOW] resulting string length is > INT_MAX,
+     - [EINVAL] invalid format string,
+     - [EILSEQ] error during conversion between wide and multibyte characters,
+   return NULL.  */
+extern char *xasprintf (const char *format, ...)
+       __attribute__ ((__format__ (__printf__, 1, 2)));
+extern char *xvasprintf (const char *format, va_list args)
+       __attribute__ ((__format__ (__printf__, 1, 0)));
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* _XVASPRINTF_H */
diff --git a/src/bin/m4/src/Jamfile b/src/bin/m4/src/Jamfile
new file mode 100644
index 0000000000..e19888352e
--- /dev/null
+++ b/src/bin/m4/src/Jamfile
@@ -0,0 +1,24 @@
+SubDir HAIKU_TOP src bin m4 src ;
+
+#SubDirCcFlags -DHAVE_CONFIG_H   -DPKGDATADIR=\'\"/etc\"\' -DLOCALEDIR=\'\"/etc/locale\"\' ;
+
+SubDirSysHdrs [ FDirName $(SUBDIR) $(DOTDOT) lib ] ;
+SubDirSysHdrs [ FDirName $(SUBDIR) $(DOTDOT) ] ;
+
+BinCommand m4 :
+	builtin.c
+	debug.c
+	eval.c
+	format.c
+	freeze.c
+	input.c
+	m4.c
+	macro.c
+	output.c
+	path.c
+	#stackovf.c
+	symtab.c
+	: libm4.a
+	: m4.rdef
+;
+
diff --git a/src/bin/m4/src/Makefile.am b/src/bin/m4/src/Makefile.am
new file mode 100644
index 0000000000..ac7f1a82fc
--- /dev/null
+++ b/src/bin/m4/src/Makefile.am
@@ -0,0 +1,30 @@
+## This file is part of GNU M4.
+##
+## Copyright (C) 2006 Free Software Foundation, Inc.
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; see the file COPYING.  If not, write to
+## the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+## Boston, MA 02110-1301, USA.
+##
+## This file written by Eric Blake <ebb9@byu.net>
+
+AUTOMAKE_OPTIONS = nostdinc
+AM_CPPFLAGS = -I$(top_srcdir)/lib -I../lib
+bin_PROGRAMS = m4
+m4_SOURCES = m4.h m4.c builtin.c debug.c eval.c format.c freeze.c input.c \
+macro.c output.c path.c symtab.c
+if STACKOVF
+m4_SOURCES += stackovf.c
+endif
+m4_LDADD = ../lib/libm4.a $(LIBM4_LIBDEPS)
diff --git a/src/bin/m4/src/Makefile.in b/src/bin/m4/src/Makefile.in
new file mode 100644
index 0000000000..c73eeebd0e
--- /dev/null
+++ b/src/bin/m4/src/Makefile.in
@@ -0,0 +1,510 @@
+# Makefile.in generated by automake 1.10 from Makefile.am.
+# @configure_input@
+
+# Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
+# 2003, 2004, 2005, 2006  Free Software Foundation, Inc.
+# This Makefile.in is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+@SET_MAKE@
+
+VPATH = @srcdir@
+pkgdatadir = $(datadir)/@PACKAGE@
+pkglibdir = $(libdir)/@PACKAGE@
+pkgincludedir = $(includedir)/@PACKAGE@
+am__cd = CDPATH="$${ZSH_VERSION+.}$(PATH_SEPARATOR)" && cd
+install_sh_DATA = $(install_sh) -c -m 644
+install_sh_PROGRAM = $(install_sh) -c
+install_sh_SCRIPT = $(install_sh) -c
+INSTALL_HEADER = $(INSTALL_DATA)
+transform = $(program_transform_name)
+NORMAL_INSTALL = :
+PRE_INSTALL = :
+POST_INSTALL = :
+NORMAL_UNINSTALL = :
+PRE_UNINSTALL = :
+POST_UNINSTALL = :
+build_triplet = @build@
+host_triplet = @host@
+bin_PROGRAMS = m4$(EXEEXT)
+@STACKOVF_TRUE@am__append_1 = stackovf.c
+subdir = src
+DIST_COMMON = $(srcdir)/Makefile.am $(srcdir)/Makefile.in
+ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
+am__aclocal_m4_deps = $(top_srcdir)/m4/absolute-header.m4 \
+	$(top_srcdir)/m4/alloca.m4 $(top_srcdir)/m4/allocsa.m4 \
+	$(top_srcdir)/m4/cloexec.m4 $(top_srcdir)/m4/close-stream.m4 \
+	$(top_srcdir)/m4/closeout.m4 $(top_srcdir)/m4/codeset.m4 \
+	$(top_srcdir)/m4/config-h.m4 $(top_srcdir)/m4/eealloc.m4 \
+	$(top_srcdir)/m4/eoverflow.m4 $(top_srcdir)/m4/error.m4 \
+	$(top_srcdir)/m4/exitfail.m4 $(top_srcdir)/m4/extensions.m4 \
+	$(top_srcdir)/m4/fatal-signal.m4 $(top_srcdir)/m4/fpending.m4 \
+	$(top_srcdir)/m4/free.m4 $(top_srcdir)/m4/getopt.m4 \
+	$(top_srcdir)/m4/gl_list.m4 $(top_srcdir)/m4/gnulib-comp.m4 \
+	$(top_srcdir)/m4/inline.m4 $(top_srcdir)/m4/intmax_t.m4 \
+	$(top_srcdir)/m4/inttypes_h.m4 $(top_srcdir)/m4/longdouble.m4 \
+	$(top_srcdir)/m4/longlong.m4 $(top_srcdir)/m4/mbchar.m4 \
+	$(top_srcdir)/m4/mbiter.m4 $(top_srcdir)/m4/mbrtowc.m4 \
+	$(top_srcdir)/m4/mbstate_t.m4 $(top_srcdir)/m4/memchr.m4 \
+	$(top_srcdir)/m4/mkdtemp.m4 $(top_srcdir)/m4/mkstemp.m4 \
+	$(top_srcdir)/m4/pathmax.m4 $(top_srcdir)/m4/quotearg.m4 \
+	$(top_srcdir)/m4/regex.m4 $(top_srcdir)/m4/sig_atomic_t.m4 \
+	$(top_srcdir)/m4/signalblocking.m4 \
+	$(top_srcdir)/m4/size_max.m4 $(top_srcdir)/m4/ssize_t.m4 \
+	$(top_srcdir)/m4/stdarg.m4 $(top_srcdir)/m4/stdbool.m4 \
+	$(top_srcdir)/m4/stdint.m4 $(top_srcdir)/m4/stdint_h.m4 \
+	$(top_srcdir)/m4/stdio-safer.m4 \
+	$(top_srcdir)/m4/stdlib-safer.m4 $(top_srcdir)/m4/strcase.m4 \
+	$(top_srcdir)/m4/strstr.m4 $(top_srcdir)/m4/strtol.m4 \
+	$(top_srcdir)/m4/sys_stat_h.m4 $(top_srcdir)/m4/tempname.m4 \
+	$(top_srcdir)/m4/tmpdir.m4 $(top_srcdir)/m4/ulonglong.m4 \
+	$(top_srcdir)/m4/unistd-safer.m4 $(top_srcdir)/m4/unistd_h.m4 \
+	$(top_srcdir)/m4/unlocked-io.m4 $(top_srcdir)/m4/vasnprintf.m4 \
+	$(top_srcdir)/m4/vasprintf.m4 $(top_srcdir)/m4/wchar_t.m4 \
+	$(top_srcdir)/m4/wcwidth.m4 $(top_srcdir)/m4/wint_t.m4 \
+	$(top_srcdir)/m4/xalloc.m4 $(top_srcdir)/m4/xsize.m4 \
+	$(top_srcdir)/m4/xvasprintf.m4 $(top_srcdir)/acinclude.m4 \
+	$(top_srcdir)/configure.ac
+am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
+	$(ACLOCAL_M4)
+mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = $(top_builddir)/lib/config.h
+CONFIG_CLEAN_FILES =
+am__installdirs = "$(DESTDIR)$(bindir)"
+binPROGRAMS_INSTALL = $(INSTALL_PROGRAM)
+PROGRAMS = $(bin_PROGRAMS)
+am__m4_SOURCES_DIST = m4.h m4.c builtin.c debug.c eval.c format.c \
+	freeze.c input.c macro.c output.c path.c symtab.c stackovf.c
+@STACKOVF_TRUE@am__objects_1 = stackovf.$(OBJEXT)
+am_m4_OBJECTS = m4.$(OBJEXT) builtin.$(OBJEXT) debug.$(OBJEXT) \
+	eval.$(OBJEXT) format.$(OBJEXT) freeze.$(OBJEXT) \
+	input.$(OBJEXT) macro.$(OBJEXT) output.$(OBJEXT) \
+	path.$(OBJEXT) symtab.$(OBJEXT) $(am__objects_1)
+m4_OBJECTS = $(am_m4_OBJECTS)
+am__DEPENDENCIES_1 =
+m4_DEPENDENCIES = ../lib/libm4.a $(am__DEPENDENCIES_1)
+DEFAULT_INCLUDES = 
+depcomp = $(SHELL) $(top_srcdir)/depcomp
+am__depfiles_maybe = depfiles
+COMPILE = $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
+	$(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
+CCLD = $(CC)
+LINK = $(CCLD) $(AM_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@
+SOURCES = $(m4_SOURCES)
+DIST_SOURCES = $(am__m4_SOURCES_DIST)
+ETAGS = etags
+CTAGS = ctags
+DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
+ABSOLUTE_STDINT_H = @ABSOLUTE_STDINT_H@
+ABSOLUTE_SYS_STAT_H = @ABSOLUTE_SYS_STAT_H@
+ACLOCAL = @ACLOCAL@
+ALLOCA = @ALLOCA@
+ALLOCA_H = @ALLOCA_H@
+AMTAR = @AMTAR@
+AUTOCONF = @AUTOCONF@
+AUTOHEADER = @AUTOHEADER@
+AUTOMAKE = @AUTOMAKE@
+AWK = @AWK@
+BITSIZEOF_PTRDIFF_T = @BITSIZEOF_PTRDIFF_T@
+BITSIZEOF_SIG_ATOMIC_T = @BITSIZEOF_SIG_ATOMIC_T@
+BITSIZEOF_SIZE_T = @BITSIZEOF_SIZE_T@
+BITSIZEOF_WCHAR_T = @BITSIZEOF_WCHAR_T@
+BITSIZEOF_WINT_T = @BITSIZEOF_WINT_T@
+CC = @CC@
+CCDEPMODE = @CCDEPMODE@
+CFLAGS = @CFLAGS@
+CPP = @CPP@
+CPPFLAGS = @CPPFLAGS@
+CYGPATH_W = @CYGPATH_W@
+DEFS = @DEFS@
+DEPDIR = @DEPDIR@
+ECHO_C = @ECHO_C@
+ECHO_N = @ECHO_N@
+ECHO_T = @ECHO_T@
+EGREP = @EGREP@
+EOVERFLOW = @EOVERFLOW@
+EXEEXT = @EXEEXT@
+GETOPT_H = @GETOPT_H@
+GREP = @GREP@
+HAVE_INTTYPES_H = @HAVE_INTTYPES_H@
+HAVE_LONG_LONG_INT = @HAVE_LONG_LONG_INT@
+HAVE_SIGNED_SIG_ATOMIC_T = @HAVE_SIGNED_SIG_ATOMIC_T@
+HAVE_SIGNED_WCHAR_T = @HAVE_SIGNED_WCHAR_T@
+HAVE_SIGNED_WINT_T = @HAVE_SIGNED_WINT_T@
+HAVE_STDINT_H = @HAVE_STDINT_H@
+HAVE_SYS_BITYPES_H = @HAVE_SYS_BITYPES_H@
+HAVE_SYS_INTTYPES_H = @HAVE_SYS_INTTYPES_H@
+HAVE_SYS_TYPES_H = @HAVE_SYS_TYPES_H@
+HAVE_UNSIGNED_LONG_LONG_INT = @HAVE_UNSIGNED_LONG_LONG_INT@
+HAVE_WCHAR_H = @HAVE_WCHAR_H@
+HAVE__BOOL = @HAVE__BOOL@
+INSTALL = @INSTALL@
+INSTALL_DATA = @INSTALL_DATA@
+INSTALL_PROGRAM = @INSTALL_PROGRAM@
+INSTALL_SCRIPT = @INSTALL_SCRIPT@
+INSTALL_STRIP_PROGRAM = @INSTALL_STRIP_PROGRAM@
+LDFLAGS = @LDFLAGS@
+LIBM4_LIBDEPS = @LIBM4_LIBDEPS@
+LIBM4_LTLIBDEPS = @LIBM4_LTLIBDEPS@
+LIBOBJS = @LIBOBJS@
+LIBS = @LIBS@
+LTLIBOBJS = @LTLIBOBJS@
+M4_LIBOBJS = @M4_LIBOBJS@
+M4_LTLIBOBJS = @M4_LTLIBOBJS@
+MAKEINFO = @MAKEINFO@
+MKDIR_P = @MKDIR_P@
+OBJEXT = @OBJEXT@
+PACKAGE = @PACKAGE@
+PACKAGE_BUGREPORT = @PACKAGE_BUGREPORT@
+PACKAGE_NAME = @PACKAGE_NAME@
+PACKAGE_STRING = @PACKAGE_STRING@
+PACKAGE_TARNAME = @PACKAGE_TARNAME@
+PACKAGE_VERSION = @PACKAGE_VERSION@
+PATH_SEPARATOR = @PATH_SEPARATOR@
+PTRDIFF_T_SUFFIX = @PTRDIFF_T_SUFFIX@
+RANLIB = @RANLIB@
+SET_MAKE = @SET_MAKE@
+SHELL = @SHELL@
+SIG_ATOMIC_T_SUFFIX = @SIG_ATOMIC_T_SUFFIX@
+SIZE_T_SUFFIX = @SIZE_T_SUFFIX@
+STDBOOL_H = @STDBOOL_H@
+STDINT_H = @STDINT_H@
+STRIP = @STRIP@
+SYS_STAT_H = @SYS_STAT_H@
+UNISTD_H = @UNISTD_H@
+VERSION = @VERSION@
+WCHAR_T_SUFFIX = @WCHAR_T_SUFFIX@
+WINT_T_SUFFIX = @WINT_T_SUFFIX@
+abs_builddir = @abs_builddir@
+abs_srcdir = @abs_srcdir@
+abs_top_builddir = @abs_top_builddir@
+abs_top_srcdir = @abs_top_srcdir@
+ac_ct_CC = @ac_ct_CC@
+am__include = @am__include@
+am__leading_dot = @am__leading_dot@
+am__quote = @am__quote@
+am__tar = @am__tar@
+am__untar = @am__untar@
+bindir = @bindir@
+build = @build@
+build_alias = @build_alias@
+build_cpu = @build_cpu@
+build_os = @build_os@
+build_vendor = @build_vendor@
+builddir = @builddir@
+datadir = @datadir@
+datarootdir = @datarootdir@
+docdir = @docdir@
+dvidir = @dvidir@
+exec_prefix = @exec_prefix@
+host = @host@
+host_alias = @host_alias@
+host_cpu = @host_cpu@
+host_os = @host_os@
+host_vendor = @host_vendor@
+htmldir = @htmldir@
+includedir = @includedir@
+infodir = @infodir@
+install_sh = @install_sh@
+libdir = @libdir@
+libexecdir = @libexecdir@
+localedir = @localedir@
+localstatedir = @localstatedir@
+mandir = @mandir@
+mkdir_p = @mkdir_p@
+oldincludedir = @oldincludedir@
+pdfdir = @pdfdir@
+prefix = @prefix@
+program_transform_name = @program_transform_name@
+psdir = @psdir@
+sbindir = @sbindir@
+sharedstatedir = @sharedstatedir@
+srcdir = @srcdir@
+sysconfdir = @sysconfdir@
+target_alias = @target_alias@
+top_builddir = @top_builddir@
+top_srcdir = @top_srcdir@
+AUTOMAKE_OPTIONS = nostdinc
+AM_CPPFLAGS = -I$(top_srcdir)/lib -I../lib
+m4_SOURCES = m4.h m4.c builtin.c debug.c eval.c format.c freeze.c \
+	input.c macro.c output.c path.c symtab.c $(am__append_1)
+m4_LDADD = ../lib/libm4.a $(LIBM4_LIBDEPS)
+all: all-am
+
+.SUFFIXES:
+.SUFFIXES: .c .o .obj
+$(srcdir)/Makefile.in:  $(srcdir)/Makefile.am  $(am__configure_deps)
+	@for dep in $?; do \
+	  case '$(am__configure_deps)' in \
+	    *$$dep*) \
+	      cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh \
+		&& exit 0; \
+	      exit 1;; \
+	  esac; \
+	done; \
+	echo ' cd $(top_srcdir) && $(AUTOMAKE) --gnu  src/Makefile'; \
+	cd $(top_srcdir) && \
+	  $(AUTOMAKE) --gnu  src/Makefile
+.PRECIOUS: Makefile
+Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
+	@case '$?' in \
+	  *config.status*) \
+	    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
+	  *) \
+	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe)'; \
+	    cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe);; \
+	esac;
+
+$(top_builddir)/config.status: $(top_srcdir)/configure $(CONFIG_STATUS_DEPENDENCIES)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+
+$(top_srcdir)/configure:  $(am__configure_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+$(ACLOCAL_M4):  $(am__aclocal_m4_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+install-binPROGRAMS: $(bin_PROGRAMS)
+	@$(NORMAL_INSTALL)
+	test -z "$(bindir)" || $(MKDIR_P) "$(DESTDIR)$(bindir)"
+	@list='$(bin_PROGRAMS)'; for p in $$list; do \
+	  p1=`echo $$p|sed 's/$(EXEEXT)$$//'`; \
+	  if test -f $$p \
+	  ; then \
+	    f=`echo "$$p1" | sed 's,^.*/,,;$(transform);s/$$/$(EXEEXT)/'`; \
+	   echo " $(INSTALL_PROGRAM_ENV) $(binPROGRAMS_INSTALL) '$$p' '$(DESTDIR)$(bindir)/$$f'"; \
+	   $(INSTALL_PROGRAM_ENV) $(binPROGRAMS_INSTALL) "$$p" "$(DESTDIR)$(bindir)/$$f" || exit 1; \
+	  else :; fi; \
+	done
+
+uninstall-binPROGRAMS:
+	@$(NORMAL_UNINSTALL)
+	@list='$(bin_PROGRAMS)'; for p in $$list; do \
+	  f=`echo "$$p" | sed 's,^.*/,,;s/$(EXEEXT)$$//;$(transform);s/$$/$(EXEEXT)/'`; \
+	  echo " rm -f '$(DESTDIR)$(bindir)/$$f'"; \
+	  rm -f "$(DESTDIR)$(bindir)/$$f"; \
+	done
+
+clean-binPROGRAMS:
+	-test -z "$(bin_PROGRAMS)" || rm -f $(bin_PROGRAMS)
+m4$(EXEEXT): $(m4_OBJECTS) $(m4_DEPENDENCIES) 
+	@rm -f m4$(EXEEXT)
+	$(LINK) $(m4_OBJECTS) $(m4_LDADD) $(LIBS)
+
+mostlyclean-compile:
+	-rm -f *.$(OBJEXT)
+
+distclean-compile:
+	-rm -f *.tab.c
+
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/builtin.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/debug.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/eval.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/format.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/freeze.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/input.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/m4.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/macro.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/output.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/path.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/stackovf.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/symtab.Po@am__quote@
+
+.c.o:
+@am__fastdepCC_TRUE@	$(COMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $<
+@am__fastdepCC_TRUE@	mv -f $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(COMPILE) -c $<
+
+.c.obj:
+@am__fastdepCC_TRUE@	$(COMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ `$(CYGPATH_W) '$<'`
+@am__fastdepCC_TRUE@	mv -f $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(COMPILE) -c `$(CYGPATH_W) '$<'`
+
+ID: $(HEADERS) $(SOURCES) $(LISP) $(TAGS_FILES)
+	list='$(SOURCES) $(HEADERS) $(LISP) $(TAGS_FILES)'; \
+	unique=`for i in $$list; do \
+	    if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
+	  done | \
+	  $(AWK) '    { files[$$0] = 1; } \
+	       END { for (i in files) print i; }'`; \
+	mkid -fID $$unique
+tags: TAGS
+
+TAGS:  $(HEADERS) $(SOURCES)  $(TAGS_DEPENDENCIES) \
+		$(TAGS_FILES) $(LISP)
+	tags=; \
+	here=`pwd`; \
+	list='$(SOURCES) $(HEADERS)  $(LISP) $(TAGS_FILES)'; \
+	unique=`for i in $$list; do \
+	    if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
+	  done | \
+	  $(AWK) '    { files[$$0] = 1; } \
+	       END { for (i in files) print i; }'`; \
+	if test -z "$(ETAGS_ARGS)$$tags$$unique"; then :; else \
+	  test -n "$$unique" || unique=$$empty_fix; \
+	  $(ETAGS) $(ETAGSFLAGS) $(AM_ETAGSFLAGS) $(ETAGS_ARGS) \
+	    $$tags $$unique; \
+	fi
+ctags: CTAGS
+CTAGS:  $(HEADERS) $(SOURCES)  $(TAGS_DEPENDENCIES) \
+		$(TAGS_FILES) $(LISP)
+	tags=; \
+	here=`pwd`; \
+	list='$(SOURCES) $(HEADERS)  $(LISP) $(TAGS_FILES)'; \
+	unique=`for i in $$list; do \
+	    if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
+	  done | \
+	  $(AWK) '    { files[$$0] = 1; } \
+	       END { for (i in files) print i; }'`; \
+	test -z "$(CTAGS_ARGS)$$tags$$unique" \
+	  || $(CTAGS) $(CTAGSFLAGS) $(AM_CTAGSFLAGS) $(CTAGS_ARGS) \
+	     $$tags $$unique
+
+GTAGS:
+	here=`$(am__cd) $(top_builddir) && pwd` \
+	  && cd $(top_srcdir) \
+	  && gtags -i $(GTAGS_ARGS) $$here
+
+distclean-tags:
+	-rm -f TAGS ID GTAGS GRTAGS GSYMS GPATH tags
+
+distdir: $(DISTFILES)
+	@srcdirstrip=`echo "$(srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
+	topsrcdirstrip=`echo "$(top_srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
+	list='$(DISTFILES)'; \
+	  dist_files=`for file in $$list; do echo $$file; done | \
+	  sed -e "s|^$$srcdirstrip/||;t" \
+	      -e "s|^$$topsrcdirstrip/|$(top_builddir)/|;t"`; \
+	case $$dist_files in \
+	  */*) $(MKDIR_P) `echo "$$dist_files" | \
+			   sed '/\//!d;s|^|$(distdir)/|;s,/[^/]*$$,,' | \
+			   sort -u` ;; \
+	esac; \
+	for file in $$dist_files; do \
+	  if test -f $$file || test -d $$file; then d=.; else d=$(srcdir); fi; \
+	  if test -d $$d/$$file; then \
+	    dir=`echo "/$$file" | sed -e 's,/[^/]*$$,,'`; \
+	    if test -d $(srcdir)/$$file && test $$d != $(srcdir); then \
+	      cp -pR $(srcdir)/$$file $(distdir)$$dir || exit 1; \
+	    fi; \
+	    cp -pR $$d/$$file $(distdir)$$dir || exit 1; \
+	  else \
+	    test -f $(distdir)/$$file \
+	    || cp -p $$d/$$file $(distdir)/$$file \
+	    || exit 1; \
+	  fi; \
+	done
+check-am: all-am
+check: check-am
+all-am: Makefile $(PROGRAMS)
+installdirs:
+	for dir in "$(DESTDIR)$(bindir)"; do \
+	  test -z "$$dir" || $(MKDIR_P) "$$dir"; \
+	done
+install: install-am
+install-exec: install-exec-am
+install-data: install-data-am
+uninstall: uninstall-am
+
+install-am: all-am
+	@$(MAKE) $(AM_MAKEFLAGS) install-exec-am install-data-am
+
+installcheck: installcheck-am
+install-strip:
+	$(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
+	  install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
+	  `test -z '$(STRIP)' || \
+	    echo "INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'"` install
+mostlyclean-generic:
+
+clean-generic:
+
+distclean-generic:
+	-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
+
+maintainer-clean-generic:
+	@echo "This command is intended for maintainers to use"
+	@echo "it deletes files that may require special tools to rebuild."
+clean: clean-am
+
+clean-am: clean-binPROGRAMS clean-generic mostlyclean-am
+
+distclean: distclean-am
+	-rm -rf ./$(DEPDIR)
+	-rm -f Makefile
+distclean-am: clean-am distclean-compile distclean-generic \
+	distclean-tags
+
+dvi: dvi-am
+
+dvi-am:
+
+html: html-am
+
+info: info-am
+
+info-am:
+
+install-data-am:
+
+install-dvi: install-dvi-am
+
+install-exec-am: install-binPROGRAMS
+
+install-html: install-html-am
+
+install-info: install-info-am
+
+install-man:
+
+install-pdf: install-pdf-am
+
+install-ps: install-ps-am
+
+installcheck-am:
+
+maintainer-clean: maintainer-clean-am
+	-rm -rf ./$(DEPDIR)
+	-rm -f Makefile
+maintainer-clean-am: distclean-am maintainer-clean-generic
+
+mostlyclean: mostlyclean-am
+
+mostlyclean-am: mostlyclean-compile mostlyclean-generic
+
+pdf: pdf-am
+
+pdf-am:
+
+ps: ps-am
+
+ps-am:
+
+uninstall-am: uninstall-binPROGRAMS
+
+.MAKE: install-am install-strip
+
+.PHONY: CTAGS GTAGS all all-am check check-am clean clean-binPROGRAMS \
+	clean-generic ctags distclean distclean-compile \
+	distclean-generic distclean-tags distdir dvi dvi-am html \
+	html-am info info-am install install-am install-binPROGRAMS \
+	install-data install-data-am install-dvi install-dvi-am \
+	install-exec install-exec-am install-html install-html-am \
+	install-info install-info-am install-man install-pdf \
+	install-pdf-am install-ps install-ps-am install-strip \
+	installcheck installcheck-am installdirs maintainer-clean \
+	maintainer-clean-generic mostlyclean mostlyclean-compile \
+	mostlyclean-generic pdf pdf-am ps ps-am tags uninstall \
+	uninstall-am uninstall-binPROGRAMS
+
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/src/bin/m4/src/builtin.c b/src/bin/m4/src/builtin.c
new file mode 100644
index 0000000000..e7b120224d
--- /dev/null
+++ b/src/bin/m4/src/builtin.c
@@ -0,0 +1,2081 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2000, 2004, 2006
+   Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* Code for all builtin macros, initialization of symbol table, and
+   expansion of user defined macros.  */
+
+#include "m4.h"
+
+extern FILE *popen ();
+
+#include "regex.h"
+#include "strstr.h"
+
+#if HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
+
+#define ARG(i)	(argc > (i) ? TOKEN_DATA_TEXT (argv[i]) : "")
+
+/* Initialization of builtin and predefined macros.  The table
+   "builtin_tab" is both used for initialization, and by the "builtin"
+   builtin.  */
+
+#define DECLARE(name) \
+  static void name (struct obstack *, int, token_data **)
+
+DECLARE (m4___file__);
+DECLARE (m4___line__);
+DECLARE (m4___program__);
+DECLARE (m4_builtin);
+DECLARE (m4_changecom);
+DECLARE (m4_changequote);
+#ifdef ENABLE_CHANGEWORD
+DECLARE (m4_changeword);
+#endif
+DECLARE (m4_debugmode);
+DECLARE (m4_debugfile);
+DECLARE (m4_decr);
+DECLARE (m4_define);
+DECLARE (m4_defn);
+DECLARE (m4_divert);
+DECLARE (m4_divnum);
+DECLARE (m4_dnl);
+DECLARE (m4_dumpdef);
+DECLARE (m4_errprint);
+DECLARE (m4_esyscmd);
+DECLARE (m4_eval);
+DECLARE (m4_format);
+DECLARE (m4_ifdef);
+DECLARE (m4_ifelse);
+DECLARE (m4_include);
+DECLARE (m4_incr);
+DECLARE (m4_index);
+DECLARE (m4_indir);
+DECLARE (m4_len);
+DECLARE (m4_m4exit);
+DECLARE (m4_m4wrap);
+DECLARE (m4_maketemp);
+DECLARE (m4_mkstemp);
+DECLARE (m4_patsubst);
+DECLARE (m4_popdef);
+DECLARE (m4_pushdef);
+DECLARE (m4_regexp);
+DECLARE (m4_shift);
+DECLARE (m4_sinclude);
+DECLARE (m4_substr);
+DECLARE (m4_syscmd);
+DECLARE (m4_sysval);
+DECLARE (m4_traceoff);
+DECLARE (m4_traceon);
+DECLARE (m4_translit);
+DECLARE (m4_undefine);
+DECLARE (m4_undivert);
+
+#undef DECLARE
+
+static builtin
+builtin_tab[] =
+{
+
+  /* name		GNUext	macros	blind	function */
+
+  { "__file__",		true,	false,	false,	m4___file__ },
+  { "__line__",		true,	false,	false,	m4___line__ },
+  { "__program__",	true,	false,	false,	m4___program__ },
+  { "builtin",		true,	true,	true,	m4_builtin },
+  { "changecom",	false,	false,	false,	m4_changecom },
+  { "changequote",	false,	false,	false,	m4_changequote },
+#ifdef ENABLE_CHANGEWORD
+  { "changeword",	true,	false,	true,	m4_changeword },
+#endif
+  { "debugmode",	true,	false,	false,	m4_debugmode },
+  { "debugfile",	true,	false,	false,	m4_debugfile },
+  { "decr",		false,	false,	true,	m4_decr },
+  { "define",		false,	true,	true,	m4_define },
+  { "defn",		false,	false,	true,	m4_defn },
+  { "divert",		false,	false,	false,	m4_divert },
+  { "divnum",		false,	false,	false,	m4_divnum },
+  { "dnl",		false,	false,	false,	m4_dnl },
+  { "dumpdef",		false,	false,	false,	m4_dumpdef },
+  { "errprint",		false,	false,	true,	m4_errprint },
+  { "esyscmd",		true,	false,	true,	m4_esyscmd },
+  { "eval",		false,	false,	true,	m4_eval },
+  { "format",		true,	false,	true,	m4_format },
+  { "ifdef",		false,	false,	true,	m4_ifdef },
+  { "ifelse",		false,	false,	true,	m4_ifelse },
+  { "include",		false,	false,	true,	m4_include },
+  { "incr",		false,	false,	true,	m4_incr },
+  { "index",		false,	false,	true,	m4_index },
+  { "indir",		true,	true,	true,	m4_indir },
+  { "len",		false,	false,	true,	m4_len },
+  { "m4exit",		false,	false,	false,	m4_m4exit },
+  { "m4wrap",		false,	false,	true,	m4_m4wrap },
+  { "maketemp",		false,	false,	true,	m4_maketemp },
+  { "mkstemp",		false,	false,	true,	m4_mkstemp },
+  { "patsubst",		true,	false,	true,	m4_patsubst },
+  { "popdef",		false,	false,	true,	m4_popdef },
+  { "pushdef",		false,	true,	true,	m4_pushdef },
+  { "regexp",		true,	false,	true,	m4_regexp },
+  { "shift",		false,	false,	true,	m4_shift },
+  { "sinclude",		false,	false,	true,	m4_sinclude },
+  { "substr",		false,	false,	true,	m4_substr },
+  { "syscmd",		false,	false,	true,	m4_syscmd },
+  { "sysval",		false,	false,	false,	m4_sysval },
+  { "traceoff",		false,	false,	false,	m4_traceoff },
+  { "traceon",		false,	false,	false,	m4_traceon },
+  { "translit",		false,	false,	true,	m4_translit },
+  { "undefine",		false,	false,	true,	m4_undefine },
+  { "undivert",		false,	false,	false,	m4_undivert },
+
+  { 0,			false,	false,	false,	0 },
+
+  /* placeholder is intentionally stuck after the table end delimiter,
+     so that we can easily find it, while not treating it as a real
+     builtin.  */
+  { "placeholder",	true,	false,	false,	m4_placeholder },
+};
+
+static predefined const
+predefined_tab[] =
+{
+#if UNIX
+  { "unix",	"__unix__",	"" },
+#elif W32_NATIVE
+  { "windows",	"__windows__",	"" },
+#elif OS2
+  { "os2",	"__os2__",	"" },
+#else
+# warning Platform macro not provided
+#endif
+  { NULL,	"__gnu__",	"" },
+
+  { NULL,	NULL,		NULL },
+};
+
+/*----------------------------------------.
+| Find the builtin, which lives on ADDR.  |
+`----------------------------------------*/
+
+const builtin *
+find_builtin_by_addr (builtin_func *func)
+{
+  const builtin *bp;
+
+  for (bp = &builtin_tab[0]; bp->name != NULL; bp++)
+    if (bp->func == func)
+      return bp;
+  if (func == m4_placeholder)
+    return bp + 1;
+  return NULL;
+}
+
+/*----------------------------------------------------------.
+| Find the builtin, which has NAME.  On failure, return the |
+| placeholder builtin.                                      |
+`----------------------------------------------------------*/
+
+const builtin *
+find_builtin_by_name (const char *name)
+{
+  const builtin *bp;
+
+  for (bp = &builtin_tab[0]; bp->name != NULL; bp++)
+    if (strcmp (bp->name, name) == 0)
+      return bp;
+  return bp + 1;
+}
+
+/*-------------------------------------------------------------------------.
+| Install a builtin macro with name NAME, bound to the C function given in |
+| BP.  MODE is SYMBOL_INSERT or SYMBOL_PUSHDEF.  TRACED defines whether	   |
+| NAME is to be traced.							   |
+`-------------------------------------------------------------------------*/
+
+void
+define_builtin (const char *name, const builtin *bp, symbol_lookup mode)
+{
+  symbol *sym;
+
+  sym = lookup_symbol (name, mode);
+  SYMBOL_TYPE (sym) = TOKEN_FUNC;
+  SYMBOL_MACRO_ARGS (sym) = bp->groks_macro_args;
+  SYMBOL_BLIND_NO_ARGS (sym) = bp->blind_if_no_args;
+  SYMBOL_FUNC (sym) = bp->func;
+}
+
+/*-------------------------------------------------------------------------.
+| Define a predefined or user-defined macro, with name NAME, and expansion |
+| TEXT.  MODE destinguishes between the "define" and the "pushdef" case.   |
+| It is also used from main ().						   |
+`-------------------------------------------------------------------------*/
+
+void
+define_user_macro (const char *name, const char *text, symbol_lookup mode)
+{
+  symbol *s;
+
+  s = lookup_symbol (name, mode);
+  if (SYMBOL_TYPE (s) == TOKEN_TEXT)
+    free (SYMBOL_TEXT (s));
+
+  SYMBOL_TYPE (s) = TOKEN_TEXT;
+  SYMBOL_TEXT (s) = xstrdup (text ? text : "");
+}
+
+/*-----------------------------------------------.
+| Initialize all builtin and predefined macros.	 |
+`-----------------------------------------------*/
+
+void
+builtin_init (void)
+{
+  const builtin *bp;
+  const predefined *pp;
+  char *string;
+
+  for (bp = &builtin_tab[0]; bp->name != NULL; bp++)
+    if (!no_gnu_extensions || !bp->gnu_extension)
+      {
+	if (prefix_all_builtins)
+	  {
+	    string = (char *) xmalloc (strlen (bp->name) + 4);
+	    strcpy (string, "m4_");
+	    strcat (string, bp->name);
+	    define_builtin (string, bp, SYMBOL_INSERT);
+	    free (string);
+	  }
+	else
+	  define_builtin (bp->name, bp, SYMBOL_INSERT);
+      }
+
+  for (pp = &predefined_tab[0]; pp->func != NULL; pp++)
+    if (no_gnu_extensions)
+      {
+	if (pp->unix_name != NULL)
+	  define_user_macro (pp->unix_name, pp->func, SYMBOL_INSERT);
+      }
+    else
+      {
+	if (pp->gnu_name != NULL)
+	  define_user_macro (pp->gnu_name, pp->func, SYMBOL_INSERT);
+      }
+}
+
+/*------------------------------------------------------------------------.
+| Give friendly warnings if a builtin macro is passed an inappropriate	  |
+| number of arguments.  NAME is macro name for messages, ARGC is actual	  |
+| number of arguments, MIN is the minimum number of acceptable arguments, |
+| negative if not applicable, MAX is the maximum number, negative if not  |
+| applicable.								  |
+`------------------------------------------------------------------------*/
+
+static bool
+bad_argc (token_data *name, int argc, int min, int max)
+{
+  bool isbad = false;
+
+  if (min > 0 && argc < min)
+    {
+      if (!suppress_warnings)
+	M4ERROR ((warning_status, 0,
+		  "Warning: too few arguments to builtin `%s'",
+		  TOKEN_DATA_TEXT (name)));
+      isbad = true;
+    }
+  else if (max > 0 && argc > max && !suppress_warnings)
+    M4ERROR ((warning_status, 0,
+	      "Warning: excess arguments to builtin `%s' ignored",
+	      TOKEN_DATA_TEXT (name)));
+
+  return isbad;
+}
+
+/*--------------------------------------------------------------------------.
+| The function numeric_arg () converts ARG to an int pointed to by VALUEP.  |
+| If the conversion fails, print error message for macro MACRO.  Return	    |
+| true iff conversion succeeds.						    |
+`--------------------------------------------------------------------------*/
+
+static bool
+numeric_arg (token_data *macro, const char *arg, int *valuep)
+{
+  char *endp;
+
+  if (*arg == '\0')
+    {
+      *valuep = 0;
+      M4ERROR ((warning_status, 0,
+		"empty string treated as 0 in builtin `%s'",
+		TOKEN_DATA_TEXT (macro)));
+    }
+  else
+    {
+      errno = 0;
+      *valuep = strtol (arg, &endp, 10);
+      if (*endp != '\0')
+	{
+	  M4ERROR ((warning_status, 0,
+		    "non-numeric argument to builtin `%s'",
+		    TOKEN_DATA_TEXT (macro)));
+	  return false;
+	}
+      if (isspace (to_uchar (*arg)))
+	M4ERROR ((warning_status, 0,
+		  "leading whitespace ignored in builtin `%s'",
+		  TOKEN_DATA_TEXT (macro)));
+      else if (errno == ERANGE)
+	M4ERROR ((warning_status, 0,
+		  "numeric overflow detected in builtin `%s'",
+		  TOKEN_DATA_TEXT (macro)));
+    }
+  return true;
+}
+
+/*------------------------------------------------------------------------.
+| The function ntoa () converts VALUE to a signed ascii representation in |
+| radix RADIX.								  |
+`------------------------------------------------------------------------*/
+
+/* Digits for number to ascii conversions.  */
+static char const digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
+
+static const char *
+ntoa (eval_t value, int radix)
+{
+  bool negative;
+  unsigned_eval_t uvalue;
+  static char str[256];
+  char *s = &str[sizeof str];
+
+  *--s = '\0';
+
+  if (value < 0)
+    {
+      negative = true;
+      uvalue = (unsigned_eval_t) -value;
+    }
+  else
+    {
+      negative = false;
+      uvalue = (unsigned_eval_t) value;
+    }
+
+  do
+    {
+      *--s = digits[uvalue % radix];
+      uvalue /= radix;
+    }
+  while (uvalue > 0);
+
+  if (negative)
+    *--s = '-';
+  return s;
+}
+
+/*----------------------------------------------------------------------.
+| Format an int VAL, and stuff it into an obstack OBS.  Used for macros |
+| expanding to numbers.						        |
+`----------------------------------------------------------------------*/
+
+static void
+shipout_int (struct obstack *obs, int val)
+{
+  const char *s;
+
+  s = ntoa ((eval_t) val, 10);
+  obstack_grow (obs, s, strlen (s));
+}
+
+/*----------------------------------------------------------------------.
+| Print ARGC arguments from the table ARGV to obstack OBS, separated by |
+| SEP, and quoted by the current quotes, if QUOTED is true.	        |
+`----------------------------------------------------------------------*/
+
+static void
+dump_args (struct obstack *obs, int argc, token_data **argv,
+	   const char *sep, bool quoted)
+{
+  int i;
+  size_t len = strlen (sep);
+
+  for (i = 1; i < argc; i++)
+    {
+      if (i > 1)
+	obstack_grow (obs, sep, len);
+      if (quoted)
+	obstack_grow (obs, lquote.string, lquote.length);
+      obstack_grow (obs, TOKEN_DATA_TEXT (argv[i]),
+		    strlen (TOKEN_DATA_TEXT (argv[i])));
+      if (quoted)
+	obstack_grow (obs, rquote.string, rquote.length);
+    }
+}
+
+/* The rest of this file is code for builtins and expansion of user
+   defined macros.  All the functions for builtins have a prototype as:
+
+	void m4_MACRONAME (struct obstack *obs, int argc, char *argv[]);
+
+   The function are expected to leave their expansion on the obstack OBS,
+   as an unfinished object.  ARGV is a table of ARGC pointers to the
+   individual arguments to the macro.  Please note that in general
+   argv[argc] != NULL.  */
+
+/* The first section are macros for definining, undefining, examining,
+   changing, ... other macros.  */
+
+/*-------------------------------------------------------------------------.
+| The function define_macro is common for the builtins "define",	   |
+| "undefine", "pushdef" and "popdef".  ARGC and ARGV is as for the caller, |
+| and MODE argument determines how the macro name is entered into the	   |
+| symbol table.								   |
+`-------------------------------------------------------------------------*/
+
+static void
+define_macro (int argc, token_data **argv, symbol_lookup mode)
+{
+  const builtin *bp;
+
+  if (bad_argc (argv[0], argc, 2, 3))
+    return;
+
+  if (TOKEN_DATA_TYPE (argv[1]) != TOKEN_TEXT)
+    {
+      M4ERROR ((warning_status, 0,
+		"Warning: %s: invalid macro name ignored", ARG (0)));
+      return;
+    }
+
+  if (argc == 2)
+    {
+      define_user_macro (ARG (1), "", mode);
+      return;
+    }
+
+  switch (TOKEN_DATA_TYPE (argv[2]))
+    {
+    case TOKEN_TEXT:
+      define_user_macro (ARG (1), ARG (2), mode);
+      break;
+
+    case TOKEN_FUNC:
+      bp = find_builtin_by_addr (TOKEN_DATA_FUNC (argv[2]));
+      if (bp == NULL)
+	return;
+      else
+	define_builtin (ARG (1), bp, mode);
+      break;
+
+    default:
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: bad token data type in define_macro ()"));
+      abort ();
+    }
+}
+
+static void
+m4_define (struct obstack *obs, int argc, token_data **argv)
+{
+  define_macro (argc, argv, SYMBOL_INSERT);
+}
+
+static void
+m4_undefine (struct obstack *obs, int argc, token_data **argv)
+{
+  int i;
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  for (i = 1; i < argc; i++)
+    lookup_symbol (ARG (i), SYMBOL_DELETE);
+}
+
+static void
+m4_pushdef (struct obstack *obs, int argc, token_data **argv)
+{
+  define_macro (argc, argv,  SYMBOL_PUSHDEF);
+}
+
+static void
+m4_popdef (struct obstack *obs, int argc, token_data **argv)
+{
+  int i;
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  for (i = 1; i < argc; i++)
+    lookup_symbol (ARG (i), SYMBOL_POPDEF);
+}
+
+/*---------------------.
+| Conditionals of m4.  |
+`---------------------*/
+
+static void
+m4_ifdef (struct obstack *obs, int argc, token_data **argv)
+{
+  symbol *s;
+  const char *result;
+
+  if (bad_argc (argv[0], argc, 3, 4))
+    return;
+  s = lookup_symbol (ARG (1), SYMBOL_LOOKUP);
+
+  if (s != NULL && SYMBOL_TYPE (s) != TOKEN_VOID)
+    result = ARG (2);
+  else if (argc >= 4)
+    result = ARG (3);
+  else
+    result = NULL;
+
+  if (result != NULL)
+    obstack_grow (obs, result, strlen (result));
+}
+
+static void
+m4_ifelse (struct obstack *obs, int argc, token_data **argv)
+{
+  const char *result;
+  token_data *argv0;
+
+  if (argc == 2)
+    return;
+
+  if (bad_argc (argv[0], argc, 4, -1))
+    return;
+  else
+    /* Diagnose excess arguments if 5, 8, 11, etc., actual arguments.  */
+    bad_argc (argv[0], (argc + 2) % 3, -1, 1);
+
+  argv0 = argv[0];
+  argv++;
+  argc--;
+
+  result = NULL;
+  while (result == NULL)
+
+    if (strcmp (ARG (0), ARG (1)) == 0)
+      result = ARG (2);
+
+    else
+      switch (argc)
+	{
+	case 3:
+	  return;
+
+	case 4:
+	case 5:
+	  result = ARG (3);
+	  break;
+
+	default:
+	  argc -= 3;
+	  argv += 3;
+	}
+
+  obstack_grow (obs, result, strlen (result));
+}
+
+/*---------------------------------------------------------------------.
+| The function dump_symbol () is for use by "dumpdef".  It builds up a |
+| table of all defined, un-shadowed, symbols.			       |
+`---------------------------------------------------------------------*/
+
+/* The structure dump_symbol_data is used to pass the information needed
+   from call to call to dump_symbol.  */
+
+struct dump_symbol_data
+{
+  struct obstack *obs;		/* obstack for table */
+  symbol **base;		/* base of table */
+  int size;			/* size of table */
+};
+
+static void
+dump_symbol (symbol *sym, void *arg)
+{
+  struct dump_symbol_data *data = (struct dump_symbol_data *) arg;
+  if (!SYMBOL_SHADOWED (sym) && SYMBOL_TYPE (sym) != TOKEN_VOID)
+    {
+      obstack_blank (data->obs, sizeof (symbol *));
+      data->base = (symbol **) obstack_base (data->obs);
+      data->base[data->size++] = sym;
+    }
+}
+
+/*------------------------------------------------------------------------.
+| qsort comparison routine, for sorting the table made in m4_dumpdef ().  |
+`------------------------------------------------------------------------*/
+
+static int
+dumpdef_cmp (const void *s1, const void *s2)
+{
+  return strcmp (SYMBOL_NAME (* (symbol *const *) s1),
+		 SYMBOL_NAME (* (symbol *const *) s2));
+}
+
+/*-------------------------------------------------------------------------.
+| Implementation of "dumpdef" itself.  It builds up a table of pointers to |
+| symbols, sorts it and prints the sorted table.			   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_dumpdef (struct obstack *obs, int argc, token_data **argv)
+{
+  symbol *s;
+  int i;
+  struct dump_symbol_data data;
+  const builtin *bp;
+
+  data.obs = obs;
+  data.base = (symbol **) obstack_base (obs);
+  data.size = 0;
+
+  if (argc == 1)
+    {
+      hack_all_symbols (dump_symbol, &data);
+    }
+  else
+    {
+      for (i = 1; i < argc; i++)
+	{
+	  s = lookup_symbol (TOKEN_DATA_TEXT (argv[i]), SYMBOL_LOOKUP);
+	  if (s != NULL && SYMBOL_TYPE (s) != TOKEN_VOID)
+	    dump_symbol (s, &data);
+	  else
+	    M4ERROR ((warning_status, 0,
+		      "undefined macro `%s'", TOKEN_DATA_TEXT (argv[i])));
+	}
+    }
+
+  /* Make table of symbols invisible to expand_macro ().  */
+
+  obstack_finish (obs);
+
+  qsort (data.base, data.size, sizeof (symbol *), dumpdef_cmp);
+
+  for (; data.size > 0; --data.size, data.base++)
+    {
+      DEBUG_PRINT1 ("%s:\t", SYMBOL_NAME (data.base[0]));
+
+      switch (SYMBOL_TYPE (data.base[0]))
+	{
+	case TOKEN_TEXT:
+	  if (debug_level & DEBUG_TRACE_QUOTE)
+	    DEBUG_PRINT3 ("%s%s%s\n",
+			  lquote.string, SYMBOL_TEXT (data.base[0]), rquote.string);
+	  else
+	    DEBUG_PRINT1 ("%s\n", SYMBOL_TEXT (data.base[0]));
+	  break;
+
+	case TOKEN_FUNC:
+	  bp = find_builtin_by_addr (SYMBOL_FUNC (data.base[0]));
+	  if (bp == NULL)
+	    {
+	      M4ERROR ((warning_status, 0, "\
+INTERNAL ERROR: builtin not found in builtin table"));
+	      abort ();
+	    }
+	  DEBUG_PRINT1 ("<%s>\n", bp->name);
+	  break;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: bad token data type in m4_dumpdef ()"));
+	  abort ();
+	  break;
+	}
+    }
+}
+
+/*---------------------------------------------------------------------.
+| The builtin "builtin" allows calls to builtin macros, even if their  |
+| definition has been overridden or shadowed.  It is thus possible to  |
+| redefine builtins, and still access their original definition.  This |
+| macro is not available in compatibility mode.			       |
+`---------------------------------------------------------------------*/
+
+static void
+m4_builtin (struct obstack *obs, int argc, token_data **argv)
+{
+  const builtin *bp;
+  const char *name;
+
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  if (TOKEN_DATA_TYPE (argv[1]) != TOKEN_TEXT)
+    {
+      M4ERROR ((warning_status, 0,
+		"Warning: %s: invalid macro name ignored", ARG (0)));
+      return;
+    }
+
+  name = ARG (1);
+  bp = find_builtin_by_name (name);
+  if (bp->func == m4_placeholder)
+    M4ERROR ((warning_status, 0,
+	      "undefined builtin `%s'", name));
+  else
+    {
+      int i;
+      if (! bp->groks_macro_args)
+	for (i = 2; i < argc; i++)
+	  if (TOKEN_DATA_TYPE (argv[i]) != TOKEN_TEXT)
+	    {
+	      TOKEN_DATA_TYPE (argv[i]) = TOKEN_TEXT;
+	      TOKEN_DATA_TEXT (argv[i]) = (char *) "";
+	    }
+      bp->func (obs, argc - 1, argv + 1);
+    }
+}
+
+/*------------------------------------------------------------------------.
+| The builtin "indir" allows indirect calls to macros, even if their name |
+| is not a proper macro name.  It is thus possible to define macros with  |
+| ill-formed names for internal use in larger macro packages.  This macro |
+| is not available in compatibility mode.				  |
+`------------------------------------------------------------------------*/
+
+static void
+m4_indir (struct obstack *obs, int argc, token_data **argv)
+{
+  symbol *s;
+  const char *name;
+
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  if (TOKEN_DATA_TYPE (argv[1]) != TOKEN_TEXT)
+    {
+      M4ERROR ((warning_status, 0,
+		"Warning: %s: invalid macro name ignored", ARG (0)));
+      return;
+    }
+
+  name = ARG (1);
+  s = lookup_symbol (name, SYMBOL_LOOKUP);
+  if (s == NULL || SYMBOL_TYPE (s) == TOKEN_VOID)
+    M4ERROR ((warning_status, 0,
+	      "undefined macro `%s'", name));
+  else
+    {
+      int i;
+      if (! SYMBOL_MACRO_ARGS (s))
+	for (i = 2; i < argc; i++)
+	  if (TOKEN_DATA_TYPE (argv[i]) != TOKEN_TEXT)
+	    {
+	      TOKEN_DATA_TYPE (argv[i]) = TOKEN_TEXT;
+	      TOKEN_DATA_TEXT (argv[i]) = (char *) "";
+	    }
+      call_macro (s, argc - 1, argv + 1, obs);
+    }
+}
+
+/*-------------------------------------------------------------------------.
+| The macro "defn" returns the quoted definition of the macro named by the |
+| first argument.  If the macro is builtin, it will push a special	   |
+| macro-definition token on the input stack.				   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_defn (struct obstack *obs, int argc, token_data **argv)
+{
+  symbol *s;
+  builtin_func *b;
+
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+
+  s = lookup_symbol (ARG (1), SYMBOL_LOOKUP);
+  if (s == NULL)
+    return;
+
+  switch (SYMBOL_TYPE (s))
+    {
+    case TOKEN_TEXT:
+      obstack_grow (obs, lquote.string, lquote.length);
+      obstack_grow (obs, SYMBOL_TEXT (s), strlen (SYMBOL_TEXT (s)));
+      obstack_grow (obs, rquote.string, rquote.length);
+      break;
+
+    case TOKEN_FUNC:
+      b = SYMBOL_FUNC (s);
+      if (b == m4_placeholder)
+	M4ERROR ((warning_status, 0, "\
+builtin `%s' requested by frozen file is not supported", ARG (1)));
+      else
+	push_macro (b);
+      break;
+
+    case TOKEN_VOID:
+      break;
+
+    default:
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: bad symbol type in m4_defn ()"));
+      abort ();
+    }
+}
+
+/*------------------------------------------------------------------------.
+| This section contains macros to handle the builtins "syscmd", "esyscmd" |
+| and "sysval".  "esyscmd" is GNU specific.				  |
+`------------------------------------------------------------------------*/
+
+/* Helper macros for readability.  */
+#if UNIX || defined WEXITSTATUS
+# define M4SYSVAL_EXITBITS(status)                       \
+   (WIFEXITED (status) ? WEXITSTATUS (status) : 0)
+# define M4SYSVAL_TERMSIGBITS(status)                    \
+   (WIFSIGNALED (status) ? WTERMSIG (status) << 8 : 0)
+
+#else /* ! UNIX && ! defined WEXITSTATUS */
+/* Platforms such as mingw do not support the notion of reporting
+   which signal terminated a process.  Furthermore if WEXITSTATUS was
+   not provided, then the exit value is in the low eight bits.  */
+# define M4SYSVAL_EXITBITS(status) status
+# define M4SYSVAL_TERMSIGBITS(status) 0
+#endif /* ! UNIX && ! defined WEXITSTATUS */
+
+/* Fallback definitions if <stdlib.h> or <sys/wait.h> are inadequate.  */
+#ifndef WEXITSTATUS
+# define WEXITSTATUS(status) (((status) >> 8) & 0xff)
+#endif
+#ifndef WTERMSIG
+# define WTERMSIG(status) ((status) & 0x7f)
+#endif
+#ifndef WIFSIGNALED
+# define WIFSIGNALED(status) (WTERMSIG (status) != 0)
+#endif
+#ifndef WIFEXITED
+# define WIFEXITED(status) (WTERMSIG (status) == 0)
+#endif
+
+/* Exit code from last "syscmd" command.  */
+static int sysval;
+
+static void
+m4_syscmd (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, 2))
+    {
+      /* The empty command is successful.  */
+      sysval = 0;
+      return;
+    }
+
+  debug_flush_files ();
+  sysval = system (ARG (1));
+#if FUNC_SYSTEM_BROKEN
+  /* OS/2 has a buggy system() that returns exit status in the lowest eight
+     bits, although pclose() and WEXITSTATUS are defined to return exit
+     status in the next eight bits.  This approach can't detect signals, but
+     at least syscmd(`ls') still works when stdout is a terminal.  An
+     alternate approach is popen/insert_file/pclose, but that makes stdout
+     a pipe, which can change how some child processes behave.  */
+  if (sysval != -1)
+    sysval <<= 8;
+#endif /* FUNC_SYSTEM_BROKEN */
+}
+
+static void
+m4_esyscmd (struct obstack *obs, int argc, token_data **argv)
+{
+  FILE *pin;
+  int ch;
+
+  if (bad_argc (argv[0], argc, 2, 2))
+    {
+      /* The empty command is successful.  */
+      sysval = 0;
+      return;
+    }
+
+  debug_flush_files ();
+  errno = 0;
+  pin = popen (ARG (1), "r");
+  if (pin == NULL)
+    {
+      M4ERROR ((warning_status, errno,
+		"cannot open pipe to command `%s'", ARG (1)));
+      sysval = -1;
+    }
+  else
+    {
+      while ((ch = getc (pin)) != EOF)
+	obstack_1grow (obs, (char) ch);
+      sysval = pclose (pin);
+    }
+}
+
+static void
+m4_sysval (struct obstack *obs, int argc, token_data **argv)
+{
+  shipout_int (obs, (sysval == -1 ? 127
+		     : (M4SYSVAL_EXITBITS (sysval)
+			| M4SYSVAL_TERMSIGBITS (sysval))));
+}
+
+/*-------------------------------------------------------------------------.
+| This section contains the top level code for the "eval" builtin.  The	   |
+| actual work is done in the function evaluate (), which lives in eval.c.  |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_eval (struct obstack *obs, int argc, token_data **argv)
+{
+  eval_t value = 0;
+  int radix = 10;
+  int min = 1;
+  const char *s;
+
+  if (bad_argc (argv[0], argc, 2, 4))
+    return;
+
+  if (*ARG (2) && !numeric_arg (argv[0], ARG (2), &radix))
+    return;
+
+  if (radix < 1 || radix > (int) strlen (digits))
+    {
+      M4ERROR ((warning_status, 0,
+		"radix in builtin `%s' out of range (radix = %d)",
+		ARG (0), radix));
+      return;
+    }
+
+  if (argc >= 4 && !numeric_arg (argv[0], ARG (3), &min))
+    return;
+  if (min < 0)
+    {
+      M4ERROR ((warning_status, 0,
+		"negative width to builtin `%s'", ARG (0)));
+      return;
+    }
+
+  if (!*ARG (1))
+    M4ERROR ((warning_status, 0,
+	      "empty string treated as 0 in builtin `%s'", ARG (0)));
+  else if (evaluate (ARG (1), &value))
+    return;
+
+  if (radix == 1)
+    {
+      if (value < 0)
+	{
+	  obstack_1grow (obs, '-');
+	  value = -value;
+	}
+      /* This assumes 2's-complement for correctly handling INT_MIN.  */
+      while (min-- - value > 0)
+	obstack_1grow (obs, '0');
+      while (value-- != 0)
+	obstack_1grow (obs, '1');
+      obstack_1grow (obs, '\0');
+      return;
+    }
+
+  s = ntoa (value, radix);
+
+  if (*s == '-')
+    {
+      obstack_1grow (obs, '-');
+      s++;
+    }
+  for (min -= strlen (s); --min >= 0;)
+    obstack_1grow (obs, '0');
+
+  obstack_grow (obs, s, strlen (s));
+}
+
+static void
+m4_incr (struct obstack *obs, int argc, token_data **argv)
+{
+  int value;
+
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+
+  if (!numeric_arg (argv[0], ARG (1), &value))
+    return;
+
+  shipout_int (obs, value + 1);
+}
+
+static void
+m4_decr (struct obstack *obs, int argc, token_data **argv)
+{
+  int value;
+
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+
+  if (!numeric_arg (argv[0], ARG (1), &value))
+    return;
+
+  shipout_int (obs, value - 1);
+}
+
+/* This section contains the macros "divert", "undivert" and "divnum" for
+   handling diversion.  The utility functions used lives in output.c.  */
+
+/*-----------------------------------------------------------------------.
+| Divert further output to the diversion given by ARGV[1].  Out of range |
+| means discard further output.						 |
+`-----------------------------------------------------------------------*/
+
+static void
+m4_divert (struct obstack *obs, int argc, token_data **argv)
+{
+  int i = 0;
+
+  if (bad_argc (argv[0], argc, 1, 2))
+    return;
+
+  if (argc >= 2 && !numeric_arg (argv[0], ARG (1), &i))
+    return;
+
+  make_diversion (i);
+}
+
+/*-----------------------------------------------------.
+| Expand to the current diversion number, -1 if none.  |
+`-----------------------------------------------------*/
+
+static void
+m4_divnum (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 1))
+    return;
+  shipout_int (obs, current_diversion);
+}
+
+/*-----------------------------------------------------------------------.
+| Bring back the diversion given by the argument list.  If none is	 |
+| specified, bring back all diversions.  GNU specific is the option of	 |
+| undiverting named files, by passing a non-numeric argument to undivert |
+| ().									 |
+`-----------------------------------------------------------------------*/
+
+static void
+m4_undivert (struct obstack *obs, int argc, token_data **argv)
+{
+  int i, file;
+  FILE *fp;
+  char *endp;
+
+  if (argc == 1)
+    undivert_all ();
+  else
+    for (i = 1; i < argc; i++)
+      {
+	file = strtol (ARG (i), &endp, 10);
+	if (*endp == '\0' && !isspace (to_uchar (*ARG (i))))
+	  insert_diversion (file);
+	else if (no_gnu_extensions)
+	  M4ERROR ((warning_status, 0,
+		    "non-numeric argument to builtin `%s'", ARG (0)));
+	else
+	  {
+	    fp = m4_path_search (ARG (i), NULL);
+	    if (fp != NULL)
+	      {
+		insert_file (fp);
+		if (fclose (fp) == EOF)
+		  M4ERROR ((warning_status, errno,
+			    "error undiverting `%s'", ARG (i)));
+	      }
+	    else
+	      M4ERROR ((warning_status, errno,
+			"cannot undivert `%s'", ARG (i)));
+	  }
+      }
+}
+
+/* This section contains various macros, which does not fall into any
+   specific group.  These are "dnl", "shift", "changequote", "changecom"
+   and "changeword".  */
+
+/*------------------------------------------------------------------------.
+| Delete all subsequent whitespace from input.  The function skip_line () |
+| lives in input.c.							  |
+`------------------------------------------------------------------------*/
+
+static void
+m4_dnl (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 1))
+    return;
+
+  skip_line ();
+}
+
+/*-------------------------------------------------------------------------.
+| Shift all argument one to the left, discarding the first argument.  Each |
+| output argument is quoted with the current quotes.			   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_shift (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  dump_args (obs, argc - 1, argv + 1, ",", true);
+}
+
+/*--------------------------------------------------------------------------.
+| Change the current quotes.  The function set_quotes () lives in input.c.  |
+`--------------------------------------------------------------------------*/
+
+static void
+m4_changequote (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 3))
+    return;
+
+  /* Explicit NULL distinguishes between empty and missing argument.  */
+  set_quotes ((argc >= 2) ? TOKEN_DATA_TEXT (argv[1]) : NULL,
+	     (argc >= 3) ? TOKEN_DATA_TEXT (argv[2]) : NULL);
+}
+
+/*--------------------------------------------------------------------.
+| Change the current comment delimiters.  The function set_comment () |
+| lives in input.c.						      |
+`--------------------------------------------------------------------*/
+
+static void
+m4_changecom (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 3))
+    return;
+
+  /* Explicit NULL distinguishes between empty and missing argument.  */
+  set_comment ((argc >= 2) ? TOKEN_DATA_TEXT (argv[1]) : NULL,
+	       (argc >= 3) ? TOKEN_DATA_TEXT (argv[2]) : NULL);
+}
+
+#ifdef ENABLE_CHANGEWORD
+
+/*-----------------------------------------------------------------------.
+| Change the regular expression used for breaking the input into words.	 |
+| The function set_word_regexp () lives in input.c.			 |
+`-----------------------------------------------------------------------*/
+
+static void
+m4_changeword (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+
+  set_word_regexp (TOKEN_DATA_TEXT (argv[1]));
+}
+
+#endif /* ENABLE_CHANGEWORD */
+
+/* This section contains macros for inclusion of other files -- "include"
+   and "sinclude".  This differs from bringing back diversions, in that
+   the input is scanned before being copied to the output.  */
+
+/*-------------------------------------------------------------------------.
+| Generic include function.  Include the file given by the first argument, |
+| if it exists.  Complain about inaccesible files iff SILENT is false.	   |
+`-------------------------------------------------------------------------*/
+
+static void
+include (int argc, token_data **argv, bool silent)
+{
+  FILE *fp;
+  char *name;
+
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+
+  fp = m4_path_search (ARG (1), &name);
+  if (fp == NULL)
+    {
+      if (!silent)
+	M4ERROR ((warning_status, errno,
+		  "cannot open `%s'", ARG (1)));
+      return;
+    }
+
+  push_file (fp, name, true);
+  free (name);
+}
+
+/*------------------------------------------------.
+| Include a file, complaining in case of errors.  |
+`------------------------------------------------*/
+
+static void
+m4_include (struct obstack *obs, int argc, token_data **argv)
+{
+  include (argc, argv, false);
+}
+
+/*----------------------------------.
+| Include a file, ignoring errors.  |
+`----------------------------------*/
+
+static void
+m4_sinclude (struct obstack *obs, int argc, token_data **argv)
+{
+  include (argc, argv, true);
+}
+
+/* More miscellaneous builtins -- "maketemp", "errprint", "__file__",
+   "__line__", and "__program__".  The last three are GNU specific.  */
+
+/*------------------------------------------------------------------.
+| Use the first argument as at template for a temporary file name.  |
+`------------------------------------------------------------------*/
+
+/* Add trailing 'X' to NAME if necessary, securely create the file,
+   and place the new file name on OBS.  */
+static void
+mkstemp_helper (struct obstack *obs, const char *name)
+{
+  int fd;
+  int len;
+  int i;
+
+  /* Guarantee that there are six trailing 'X' characters, even if the
+     user forgot to supply them.  */
+  len = strlen (name);
+  obstack_grow (obs, name, len);
+  for (i = 0; len > 0 && i < 6; i++)
+    if (name[--len] != 'X')
+      break;
+  for (; i < 6; i++)
+    obstack_1grow (obs, 'X');
+  obstack_1grow (obs, '\0');
+
+  errno = 0;
+  fd = mkstemp ((char *) obstack_base (obs));
+  if (fd < 0)
+    {
+      M4ERROR ((0, errno, "cannot create tempfile `%s'", name));
+      obstack_free (obs, obstack_finish (obs));
+    }
+  else
+    close (fd);
+}
+
+static void
+m4_maketemp (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+  if (no_gnu_extensions)
+    {
+      /* POSIX states "any trailing 'X' characters [are] replaced with
+	 the current process ID as a string", without referencing the
+	 file system.  Horribly insecure, but we have to do it when we
+	 are in traditional mode.
+
+	 For reference, Solaris m4 does:
+	   maketemp() -> `'
+	   maketemp(X) -> `X'
+	   maketemp(XX) -> `Xn', where n is last digit of pid
+	   maketemp(XXXXXXXX) -> `X00nnnnn', where nnnnn is 16-bit pid
+      */
+      const char *str = ARG (1);
+      int len = strlen (str);
+      int i;
+      int len2;
+
+      M4ERROR ((warning_status, 0, "recommend using mkstemp instead"));
+      for (i = len; i > 1; i--)
+	if (str[i - 1] != 'X')
+	  break;
+      obstack_grow (obs, str, i);
+      str = ntoa ((eval_t) getpid (), 10);
+      len2 = strlen (str);
+      if (len2 > len - i)
+	obstack_grow0 (obs, str + len2 - (len - i), len - i);
+      else
+	{
+	  while (i++ < len - len2)
+	    obstack_1grow (obs, '0');
+	  obstack_grow0 (obs, str, len2);
+	}
+    }
+  else
+    mkstemp_helper (obs, ARG (1));
+}
+
+static void
+m4_mkstemp (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+  mkstemp_helper (obs, ARG (1));
+}
+
+/*----------------------------------------.
+| Print all arguments on standard error.  |
+`----------------------------------------*/
+
+static void
+m4_errprint (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  dump_args (obs, argc, argv, " ", false);
+  obstack_1grow (obs, '\0');
+  debug_flush_files ();
+  fprintf (stderr, "%s", (char *) obstack_finish (obs));
+  fflush (stderr);
+}
+
+static void
+m4___file__ (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 1))
+    return;
+  obstack_grow (obs, lquote.string, lquote.length);
+  obstack_grow (obs, current_file, strlen (current_file));
+  obstack_grow (obs, rquote.string, rquote.length);
+}
+
+static void
+m4___line__ (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 1))
+    return;
+  shipout_int (obs, current_line);
+}
+
+static void
+m4___program__ (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 1))
+    return;
+  obstack_grow (obs, lquote.string, lquote.length);
+  obstack_grow (obs, program_name, strlen (program_name));
+  obstack_grow (obs, rquote.string, rquote.length);
+}
+
+/* This section contains various macros for exiting, saving input until
+   EOF is seen, and tracing macro calls.  That is: "m4exit", "m4wrap",
+   "traceon" and "traceoff".  */
+
+/*-------------------------------------------------------------------------.
+| Exit immediately, with exitcode specified by the first argument, 0 if no |
+| arguments are present.						   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_m4exit (struct obstack *obs, int argc, token_data **argv)
+{
+  int exit_code = EXIT_SUCCESS;
+
+  /* Warn on bad arguments, but still exit.  */
+  bad_argc (argv[0], argc, 1, 2);
+  if (argc >= 2 && !numeric_arg (argv[0], ARG (1), &exit_code))
+    exit_code = EXIT_FAILURE;
+  if (exit_code < 0 || exit_code > 255)
+    {
+      M4ERROR ((warning_status, 0,
+		"exit status out of range: `%d'", exit_code));
+      exit_code = EXIT_FAILURE;
+    }
+  /* Change debug stream back to stderr, to force flushing debug stream and
+     detect any errors it might have encountered.  */
+  debug_set_output (NULL);
+  debug_flush_files ();
+  if (exit_code == EXIT_SUCCESS && retcode != EXIT_SUCCESS)
+    exit_code = retcode;
+  /* Propagate non-zero status to atexit handlers.  */
+  if (exit_code != EXIT_SUCCESS)
+    exit_failure = exit_code;
+  exit (exit_code);
+}
+
+/*-------------------------------------------------------------------------.
+| Save the argument text until EOF has been seen, allowing for user	   |
+| specified cleanup action.  GNU version saves all arguments, the standard |
+| version only the first.						   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_m4wrap (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  if (no_gnu_extensions)
+    obstack_grow (obs, ARG (1), strlen (ARG (1)));
+  else
+    dump_args (obs, argc, argv, " ", false);
+  obstack_1grow (obs, '\0');
+  push_wrapup ((char *) obstack_finish (obs));
+}
+
+/* Enable tracing of all specified macros, or all, if none is specified.
+   Tracing is disabled by default, when a macro is defined.  This can be
+   overridden by the "t" debug flag.  */
+
+/*-----------------------------------------------------------------------.
+| Set_trace () is used by "traceon" and "traceoff" to enable and disable |
+| tracing of a macro.  It disables tracing if DATA is NULL, otherwise it |
+| enable tracing.							 |
+`-----------------------------------------------------------------------*/
+
+static void
+set_trace (symbol *sym, void *data)
+{
+  SYMBOL_TRACED (sym) = data != NULL;
+  /* Remove placeholder from table if macro is undefined and untraced.  */
+  if (SYMBOL_TYPE (sym) == TOKEN_VOID && data == NULL)
+    lookup_symbol (SYMBOL_NAME (sym), SYMBOL_POPDEF);
+}
+
+static void
+m4_traceon (struct obstack *obs, int argc, token_data **argv)
+{
+  symbol *s;
+  int i;
+
+  if (argc == 1)
+    hack_all_symbols (set_trace, obs);
+  else
+    for (i = 1; i < argc; i++)
+      {
+	s = lookup_symbol (TOKEN_DATA_TEXT (argv[i]), SYMBOL_INSERT);
+	set_trace (s, obs);
+      }
+}
+
+/*------------------------------------------------------------------------.
+| Disable tracing of all specified macros, or all, if none is specified.  |
+`------------------------------------------------------------------------*/
+
+static void
+m4_traceoff (struct obstack *obs, int argc, token_data **argv)
+{
+  symbol *s;
+  int i;
+
+  if (argc == 1)
+    hack_all_symbols (set_trace, NULL);
+  else
+    for (i = 1; i < argc; i++)
+      {
+	s = lookup_symbol (TOKEN_DATA_TEXT (argv[i]), SYMBOL_LOOKUP);
+	if (s != NULL)
+	  set_trace (s, NULL);
+      }
+}
+
+/*----------------------------------------------------------------------.
+| On-the-fly control of the format of the tracing output.  It takes one |
+| argument, which is a character string like given to the -d option, or |
+| none in which case the debug_level is zeroed.			        |
+`----------------------------------------------------------------------*/
+
+static void
+m4_debugmode (struct obstack *obs, int argc, token_data **argv)
+{
+  int new_debug_level;
+  int change_flag;
+
+  if (bad_argc (argv[0], argc, 1, 2))
+    return;
+
+  if (argc == 1)
+    debug_level = 0;
+  else
+    {
+      if (ARG (1)[0] == '+' || ARG (1)[0] == '-')
+	{
+	  change_flag = ARG (1)[0];
+	  new_debug_level = debug_decode (ARG (1) + 1);
+	}
+      else
+	{
+	  change_flag = 0;
+	  new_debug_level = debug_decode (ARG (1));
+	}
+
+      if (new_debug_level < 0)
+	M4ERROR ((warning_status, 0,
+		  "Debugmode: bad debug flags: `%s'", ARG (1)));
+      else
+	{
+	  switch (change_flag)
+	    {
+	    case 0:
+	      debug_level = new_debug_level;
+	      break;
+
+	    case '+':
+	      debug_level |= new_debug_level;
+	      break;
+
+	    case '-':
+	      debug_level &= ~new_debug_level;
+	      break;
+	    }
+	}
+    }
+}
+
+/*-------------------------------------------------------------------------.
+| Specify the destination of the debugging output.  With one argument, the |
+| argument is taken as a file name, with no arguments, revert to stderr.   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_debugfile (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 1, 2))
+    return;
+
+  if (argc == 1)
+    debug_set_output (NULL);
+  else if (!debug_set_output (ARG (1)))
+    M4ERROR ((warning_status, errno,
+	      "cannot set error file: `%s'", ARG (1)));
+}
+
+/* This section contains text processing macros: "len", "index",
+   "substr", "translit", "format", "regexp" and "patsubst".  The last
+   three are GNU specific.  */
+
+/*---------------------------------------------.
+| Expand to the length of the first argument.  |
+`---------------------------------------------*/
+
+static void
+m4_len (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, 2))
+    return;
+  shipout_int (obs, strlen (ARG (1)));
+}
+
+/*-------------------------------------------------------------------------.
+| The macro expands to the first index of the second argument in the first |
+| argument.								   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_index (struct obstack *obs, int argc, token_data **argv)
+{
+  const char *haystack;
+  const char *result;
+  int retval;
+
+  if (bad_argc (argv[0], argc, 3, 3))
+    {
+      /* builtin(`index') is blank, but index(`abc') is 0.  */
+      if (argc == 2)
+	shipout_int (obs, 0);
+      return;
+    }
+
+  haystack = ARG (1);
+  result = strstr (haystack, ARG (2));
+  retval = result ? result - haystack : -1;
+
+  shipout_int (obs, retval);
+}
+
+/*-------------------------------------------------------------------------.
+| The macro "substr" extracts substrings from the first argument, starting |
+| from the index given by the second argument, extending for a length	   |
+| given by the third argument.  If the third argument is missing, the	   |
+| substring extends to the end of the first argument.			   |
+`-------------------------------------------------------------------------*/
+
+static void
+m4_substr (struct obstack *obs, int argc, token_data **argv)
+{
+  int start = 0;
+  int length, avail;
+
+  if (bad_argc (argv[0], argc, 3, 4))
+    {
+      /* builtin(`substr') is blank, but substr(`abc') is abc.  */
+      if (argc == 2)
+	obstack_grow (obs, ARG (1), strlen (ARG (1)));
+      return;
+    }
+
+  length = avail = strlen (ARG (1));
+  if (!numeric_arg (argv[0], ARG (2), &start))
+    return;
+
+  if (argc >= 4 && !numeric_arg (argv[0], ARG (3), &length))
+    return;
+
+  if (start < 0 || length <= 0 || start >= avail)
+    return;
+
+  if (start + length > avail)
+    length = avail - start;
+  obstack_grow (obs, ARG (1) + start, length);
+}
+
+/*------------------------------------------------------------------------.
+| For "translit", ranges are allowed in the second and third argument.	  |
+| They are expanded in the following function, and the expanded strings,  |
+| without any ranges left, are used to translate the characters of the	  |
+| first argument.  A single - (dash) can be included in the strings by	  |
+| being the first or the last character in the string.  If the first	  |
+| character in a range is after the first in the character set, the range |
+| is made backwards, thus 9-0 is the string 9876543210.			  |
+`------------------------------------------------------------------------*/
+
+static const char *
+expand_ranges (const char *s, struct obstack *obs)
+{
+  unsigned char from;
+  unsigned char to;
+
+  for (from = '\0'; *s != '\0'; from = to_uchar (*s++))
+    {
+      if (*s == '-' && from != '\0')
+	{
+	  to = to_uchar (*++s);
+	  if (to == '\0')
+	    {
+	      /* trailing dash */
+	      obstack_1grow (obs, '-');
+	      break;
+	    }
+	  else if (from <= to)
+	    {
+	      while (from++ < to)
+		obstack_1grow (obs, from);
+	    }
+	  else
+	    {
+	      while (--from >= to)
+		obstack_1grow (obs, from);
+	    }
+	}
+      else
+	obstack_1grow (obs, *s);
+    }
+  obstack_1grow (obs, '\0');
+  return (char *) obstack_finish (obs);
+}
+
+/*----------------------------------------------------------------------.
+| The macro "translit" translates all characters in the first argument, |
+| which are present in the second argument, into the corresponding      |
+| character from the third argument.  If the third argument is shorter  |
+| than the second, the extra characters in the second argument, are     |
+| deleted from the first (pueh).				        |
+`----------------------------------------------------------------------*/
+
+static void
+m4_translit (struct obstack *obs, int argc, token_data **argv)
+{
+  const char *data;
+  const char *from;
+  const char *to;
+  char map[256] = {0};
+  char found[256] = {0};
+  unsigned char ch;
+
+  if (bad_argc (argv[0], argc, 3, 4))
+    {
+      /* builtin(`translit') is blank, but translit(`abc') is abc.  */
+      if (argc == 2)
+	obstack_grow (obs, ARG (1), strlen (ARG (1)));
+      return;
+    }
+
+  from = ARG (2);
+  if (strchr (from, '-') != NULL)
+    {
+      from = expand_ranges (from, obs);
+      if (from == NULL)
+	return;
+    }
+
+  to = ARG (3);
+  if (strchr (to, '-') != NULL)
+    {
+      to = expand_ranges (to, obs);
+      if (to == NULL)
+	return;
+    }
+
+  /* Calling strchr(from) for each character in data is quadratic,
+     since both strings can be arbitrarily long.  Instead, create a
+     from-to mapping in one pass of from, then use that map in one
+     pass of data, for linear behavior.  Traditional behavior is that
+     only the first instance of a character in from is consulted,
+     hence the found map.  */
+  for ( ; (ch = *from) != '\0'; from++)
+    {
+      if (! found[ch])
+	{
+	  found[ch] = 1;
+	  map[ch] = *to;
+	}
+      if (*to != '\0')
+	to++;
+    }
+
+  for (data = ARG (1); (ch = *data) != '\0'; data++)
+    {
+      if (! found[ch])
+	obstack_1grow (obs, ch);
+      else if (map[ch])
+	obstack_1grow (obs, map[ch]);
+    }
+}
+
+/*----------------------------------------------------------------------.
+| Frontend for printf like formatting.  The function format () lives in |
+| the file format.c.						        |
+`----------------------------------------------------------------------*/
+
+static void
+m4_format (struct obstack *obs, int argc, token_data **argv)
+{
+  if (bad_argc (argv[0], argc, 2, -1))
+    return;
+  format (obs, argc - 1, argv + 1);
+}
+
+/*-------------------------------------------------------------------------.
+| Function to perform substitution by regular expressions.  Used by the	   |
+| builtins regexp and patsubst.  The changed text is placed on the	   |
+| obstack.  The substitution is REPL, with \& substituted by this part of  |
+| VICTIM matched by the last whole regular expression, taken from REGS[0], |
+| and \N substituted by the text matched by the Nth parenthesized	   |
+| sub-expression, taken from REGS[N].					   |
+`-------------------------------------------------------------------------*/
+
+static int substitute_warned = 0;
+
+static void
+substitute (struct obstack *obs, const char *victim, const char *repl,
+	    struct re_registers *regs)
+{
+  int ch;
+
+  for (;;)
+    {
+      while ((ch = *repl++) != '\\')
+	{
+	  if (ch == '\0')
+	    return;
+	  obstack_1grow (obs, ch);
+	}
+
+      switch ((ch = *repl++))
+	{
+	case '0':
+	  if (!substitute_warned)
+	    {
+	      M4ERROR ((warning_status, 0, "\
+Warning: \\0 will disappear, use \\& instead in replacements"));
+	      substitute_warned = 1;
+	    }
+	  /* Fall through.  */
+
+	case '&':
+	  obstack_grow (obs, victim + regs->start[0],
+			regs->end[0] - regs->start[0]);
+	  break;
+
+	case '1': case '2': case '3': case '4': case '5': case '6':
+	case '7': case '8': case '9':
+	  ch -= '0';
+	  if (regs->num_regs - 1 <= ch)
+	    M4ERROR ((warning_status, 0, "\
+Warning: sub-expression %d not present", ch));
+	  else if (regs->end[ch] > 0)
+	    obstack_grow (obs, victim + regs->start[ch],
+			  regs->end[ch] - regs->start[ch]);
+	  break;
+
+	case '\0':
+	  M4ERROR ((warning_status, 0, "\
+Warning: trailing \\ ignored in replacement"));
+	  return;
+
+	default:
+	  obstack_1grow (obs, ch);
+	  break;
+	}
+    }
+}
+
+/*------------------------------------------.
+| Initialize regular expression variables.  |
+`------------------------------------------*/
+
+static void
+init_pattern_buffer (struct re_pattern_buffer *buf, struct re_registers *regs)
+{
+  buf->translate = NULL;
+  buf->fastmap = NULL;
+  buf->buffer = NULL;
+  buf->allocated = 0;
+  regs->start = NULL;
+  regs->end = NULL;
+}
+
+/*----------------------------------------.
+| Clean up regular expression variables.  |
+`----------------------------------------*/
+
+static void
+free_pattern_buffer (struct re_pattern_buffer *buf, struct re_registers *regs)
+{
+  regfree (buf);
+  free (regs->start);
+  free (regs->end);
+}
+
+/*--------------------------------------------------------------------------.
+| Regular expression version of index.  Given two arguments, expand to the  |
+| index of the first match of the second argument (a regexp) in the first.  |
+| Expand to -1 if here is no match.  Given a third argument, is changes	    |
+| the expansion to this argument.					    |
+`--------------------------------------------------------------------------*/
+
+static void
+m4_regexp (struct obstack *obs, int argc, token_data **argv)
+{
+  const char *victim;		/* first argument */
+  const char *regexp;		/* regular expression */
+  const char *repl;		/* replacement string */
+
+  struct re_pattern_buffer buf;	/* compiled regular expression */
+  struct re_registers regs;	/* for subexpression matches */
+  const char *msg;		/* error message from re_compile_pattern */
+  int startpos;			/* start position of match */
+  int length;			/* length of first argument */
+
+  if (bad_argc (argv[0], argc, 3, 4))
+    {
+      /* builtin(`regexp') is blank, but regexp(`abc') is 0.  */
+      if (argc == 2)
+	shipout_int (obs, 0);
+      return;
+    }
+
+  victim = TOKEN_DATA_TEXT (argv[1]);
+  regexp = TOKEN_DATA_TEXT (argv[2]);
+
+  init_pattern_buffer (&buf, &regs);
+  msg = re_compile_pattern (regexp, strlen (regexp), &buf);
+
+  if (msg != NULL)
+    {
+      M4ERROR ((warning_status, 0,
+		"bad regular expression: `%s': %s", regexp, msg));
+      free_pattern_buffer (&buf, &regs);
+      return;
+    }
+
+  length = strlen (victim);
+  /* Avoid overhead of allocating regs if we won't use it.  */
+  startpos = re_search (&buf, victim, length, 0, length,
+			argc == 3 ? NULL : &regs);
+
+  if (startpos == -2)
+    M4ERROR ((warning_status, 0,
+	       "error matching regular expression `%s'", regexp));
+  else if (argc == 3)
+    shipout_int (obs, startpos);
+  else if (startpos >= 0)
+    {
+      repl = TOKEN_DATA_TEXT (argv[3]);
+      substitute (obs, victim, repl, &regs);
+    }
+
+  free_pattern_buffer (&buf, &regs);
+}
+
+/*--------------------------------------------------------------------------.
+| Substitute all matches of a regexp occuring in a string.  Each match of   |
+| the second argument (a regexp) in the first argument is changed to the    |
+| third argument, with \& substituted by the matched text, and \N	    |
+| substituted by the text matched by the Nth parenthesized sub-expression.  |
+`--------------------------------------------------------------------------*/
+
+static void
+m4_patsubst (struct obstack *obs, int argc, token_data **argv)
+{
+  const char *victim;		/* first argument */
+  const char *regexp;		/* regular expression */
+
+  struct re_pattern_buffer buf;	/* compiled regular expression */
+  struct re_registers regs;	/* for subexpression matches */
+  const char *msg;		/* error message from re_compile_pattern */
+  int matchpos;			/* start position of match */
+  int offset;			/* current match offset */
+  int length;			/* length of first argument */
+
+  if (bad_argc (argv[0], argc, 3, 4))
+    {
+      /* builtin(`patsubst') is blank, but patsubst(`abc') is abc.  */
+      if (argc == 2)
+	obstack_grow (obs, ARG (1), strlen (ARG (1)));
+      return;
+    }
+
+  regexp = TOKEN_DATA_TEXT (argv[2]);
+
+  init_pattern_buffer (&buf, &regs);
+  msg = re_compile_pattern (regexp, strlen (regexp), &buf);
+
+  if (msg != NULL)
+    {
+      M4ERROR ((warning_status, 0,
+		"bad regular expression `%s': %s", regexp, msg));
+      free (buf.buffer);
+      return;
+    }
+
+  victim = TOKEN_DATA_TEXT (argv[1]);
+  length = strlen (victim);
+
+  offset = 0;
+  matchpos = 0;
+  while (offset <= length)
+    {
+      matchpos = re_search (&buf, victim, length,
+			    offset, length - offset, &regs);
+      if (matchpos < 0)
+	{
+
+	  /* Match failed -- either error or there is no match in the
+	     rest of the string, in which case the rest of the string is
+	     copied verbatim.  */
+
+	  if (matchpos == -2)
+	    M4ERROR ((warning_status, 0,
+		      "error matching regular expression `%s'", regexp));
+	  else if (offset < length)
+	    obstack_grow (obs, victim + offset, length - offset);
+	  break;
+	}
+
+      /* Copy the part of the string that was skipped by re_search ().  */
+
+      if (matchpos > offset)
+	obstack_grow (obs, victim + offset, matchpos - offset);
+
+      /* Handle the part of the string that was covered by the match.  */
+
+      substitute (obs, victim, ARG (3), &regs);
+
+      /* Update the offset to the end of the match.  If the regexp
+	 matched a null string, advance offset one more, to avoid
+	 infinite loops.  */
+
+      offset = regs.end[0];
+      if (regs.start[0] == regs.end[0])
+	obstack_1grow (obs, victim[offset++]);
+    }
+  obstack_1grow (obs, '\0');
+
+  free_pattern_buffer (&buf, &regs);
+}
+
+/* Finally, a placeholder builtin.  This builtin is not installed by
+   default, but when reading back frozen files, this is associated
+   with any builtin we don't recognize (for example, if the frozen
+   file was created with a changeword capable m4, but is then loaded
+   by a different m4 that does not support changeword).  This way, we
+   can keep 'm4 -R' quiet in the common case that the user did not
+   know or care about the builtin when the frozen file was created,
+   while still flagging it as a potential error if an attempt is made
+   to actually use the builtin.  */
+
+/*--------------------------------------------------------------------.
+| Issue a warning that this macro is a placeholder for an unsupported |
+| builtin that was requested while reloading a frozen file.           |
+`--------------------------------------------------------------------*/
+
+void
+m4_placeholder (struct obstack *obs, int argc, token_data **argv)
+{
+  M4ERROR ((warning_status, 0, "\
+builtin `%s' requested by frozen file is not supported", ARG (0)));
+}
+
+/*-------------------------------------------------------------------------.
+| This function handles all expansion of user defined and predefined	   |
+| macros.  It is called with an obstack OBS, where the macros expansion	   |
+| will be placed, as an unfinished object.  SYM points to the macro	   |
+| definition, giving the expansion text.  ARGC and ARGV are the arguments, |
+| as usual.								   |
+`-------------------------------------------------------------------------*/
+
+void
+expand_user_macro (struct obstack *obs, symbol *sym,
+		   int argc, token_data **argv)
+{
+  const char *text;
+  int i;
+
+  for (text = SYMBOL_TEXT (sym); *text != '\0';)
+    {
+      if (*text != '$')
+	{
+	  obstack_1grow (obs, *text);
+	  text++;
+	  continue;
+	}
+      text++;
+      switch (*text)
+	{
+	case '0': case '1': case '2': case '3': case '4':
+	case '5': case '6': case '7': case '8': case '9':
+	  if (no_gnu_extensions)
+	    {
+	      i = *text++ - '0';
+	    }
+	  else
+	    {
+	      for (i = 0; isdigit (to_uchar (*text)); text++)
+		i = i*10 + (*text - '0');
+	    }
+	  if (i < argc)
+	    obstack_grow (obs, TOKEN_DATA_TEXT (argv[i]),
+			  strlen (TOKEN_DATA_TEXT (argv[i])));
+	  break;
+
+	case '#':		/* number of arguments */
+	  shipout_int (obs, argc - 1);
+	  text++;
+	  break;
+
+	case '*':		/* all arguments */
+	case '@':		/* ... same, but quoted */
+	  dump_args (obs, argc, argv, ",", *text == '@');
+	  text++;
+	  break;
+
+	default:
+	  obstack_1grow (obs, '$');
+	  break;
+	}
+    }
+}
diff --git a/src/bin/m4/src/debug.c b/src/bin/m4/src/debug.c
new file mode 100644
index 0000000000..44354d0249
--- /dev/null
+++ b/src/bin/m4/src/debug.c
@@ -0,0 +1,448 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1991, 1992, 1993, 1994, 2004, 2006 Free Software
+   Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+#include "m4.h"
+
+#include <stdarg.h>
+#include <sys/stat.h>
+
+/* File for debugging output.  */
+FILE *debug = NULL;
+
+/* Obstack for trace messages.  */
+static struct obstack trace;
+
+extern int expansion_level;
+
+static void debug_set_file (FILE *);
+
+/*----------------------------------.
+| Initialise the debugging module.  |
+`----------------------------------*/
+
+void
+debug_init (void)
+{
+  debug_set_file (stderr);
+  obstack_init (&trace);
+}
+
+/*-----------------------------------------------------------------.
+| Function to decode the debugging flags OPTS.  Used by main while |
+| processing option -d, and by the builtin debugmode ().	   |
+`-----------------------------------------------------------------*/
+
+int
+debug_decode (const char *opts)
+{
+  int level;
+
+  if (opts == NULL || *opts == '\0')
+    level = DEBUG_TRACE_DEFAULT;
+  else
+    {
+      for (level = 0; *opts; opts++)
+	{
+	  switch (*opts)
+	    {
+	    case 'a':
+	      level |= DEBUG_TRACE_ARGS;
+	      break;
+
+	    case 'e':
+	      level |= DEBUG_TRACE_EXPANSION;
+	      break;
+
+	    case 'q':
+	      level |= DEBUG_TRACE_QUOTE;
+	      break;
+
+	    case 't':
+	      level |= DEBUG_TRACE_ALL;
+	      break;
+
+	    case 'l':
+	      level |= DEBUG_TRACE_LINE;
+	      break;
+
+	    case 'f':
+	      level |= DEBUG_TRACE_FILE;
+	      break;
+
+	    case 'p':
+	      level |= DEBUG_TRACE_PATH;
+	      break;
+
+	    case 'c':
+	      level |= DEBUG_TRACE_CALL;
+	      break;
+
+	    case 'i':
+	      level |= DEBUG_TRACE_INPUT;
+	      break;
+
+	    case 'x':
+	      level |= DEBUG_TRACE_CALLID;
+	      break;
+
+	    case 'V':
+	      level |= DEBUG_TRACE_VERBOSE;
+	      break;
+
+	    default:
+	      return -1;
+	    }
+	}
+    }
+
+  /* This is to avoid screwing up the trace output due to changes in the
+     debug_level.  */
+
+  obstack_free (&trace, obstack_finish (&trace));
+
+  return level;
+}
+
+/*------------------------------------------------------------------------.
+| Change the debug output stream to FP.  If the underlying file is the	  |
+| same as stdout, use stdout instead so that debug messages appear in the |
+| correct relative position.						  |
+`------------------------------------------------------------------------*/
+
+static void
+debug_set_file (FILE *fp)
+{
+  struct stat stdout_stat, debug_stat;
+
+  if (debug != NULL && debug != stderr && debug != stdout
+      && close_stream (debug) != 0)
+    {
+      M4ERROR ((warning_status, errno, "error writing to debug stream"));
+      retcode = EXIT_FAILURE;
+    }
+  debug = fp;
+
+  if (debug != NULL && debug != stdout)
+    {
+      if (fstat (STDOUT_FILENO, &stdout_stat) < 0)
+	return;
+      if (fstat (fileno (debug), &debug_stat) < 0)
+	return;
+
+      /* mingw has a bug where fstat on a regular file reports st_ino
+	 of 0.  On normal system, st_ino should never be 0.  */
+      if (stdout_stat.st_ino == debug_stat.st_ino
+	  && stdout_stat.st_dev == debug_stat.st_dev
+	  && stdout_stat.st_ino != 0)
+	{
+	  if (debug != stderr && close_stream (debug) != 0)
+	    {
+	      M4ERROR ((warning_status, errno,
+			"error writing to debug stream"));
+	      retcode = EXIT_FAILURE;
+	    }
+	  debug = stdout;
+	}
+    }
+}
+
+/*-----------------------------------------------------------.
+| Serialize files.  Used before executing a system command.  |
+`-----------------------------------------------------------*/
+
+void
+debug_flush_files (void)
+{
+  fflush (stdout);
+  fflush (stderr);
+  if (debug != NULL && debug != stdout && debug != stderr)
+    fflush (debug);
+  /* POSIX requires that if m4 doesn't consume all input, but stdin is
+     opened on a seekable file, that the file pointer be left at the
+     next character on exit (but places no restrictions on the file
+     pointer location on a non-seekable file).  It also requires that
+     fflush() followed by fseek() on an input file set the underlying
+     file pointer.  However, fflush() on a non-seekable file can lose
+     buffered data, which we might otherwise want to process after
+     syscmd.  Hence, we must check whether stdin is seekable.  We must
+     also be tolerant of operating with stdin closed, so we don't
+     report any failures in this attempt.  The stdio-safer module and
+     friends are essential, so that if stdin was closed, this lseek is
+     not on some other file that we have since opened.  Mingw has bugs
+     when using fseek on text files, so we only strive for POSIX
+     behavior when we detect a UNIX environment.  */
+#if UNIX
+  if (lseek (STDIN_FILENO, 0, SEEK_CUR) >= 0
+      && fflush (stdin) == 0)
+    {
+      fseek (stdin, 0, SEEK_CUR);
+    }
+#endif /* UNIX */
+}
+
+/*-------------------------------------------------------------------------.
+| Change the debug output to file NAME.  If NAME is NULL, debug output is  |
+| reverted to stderr, and if empty debug output is discarded.  Return true |
+| iff the output stream was changed.					   |
+`-------------------------------------------------------------------------*/
+
+bool
+debug_set_output (const char *name)
+{
+  FILE *fp;
+
+  if (name == NULL)
+    debug_set_file (stderr);
+  else if (*name == '\0')
+    debug_set_file (NULL);
+  else
+    {
+      fp = fopen (name, "a");
+      if (fp == NULL)
+	return false;
+
+      if (set_cloexec_flag (fileno (fp), true) != 0)
+	M4ERROR ((warning_status, errno,
+		  "Warning: cannot protect debug file across forks"));
+      debug_set_file (fp);
+    }
+  return true;
+}
+
+/*-----------------------------------------------------------------------.
+| Print the header of a one-line debug message, starting by "m4 debug".	 |
+`-----------------------------------------------------------------------*/
+
+void
+debug_message_prefix (void)
+{
+  fprintf (debug, "m4debug:");
+  if (current_line)
+  {
+    if (debug_level & DEBUG_TRACE_FILE)
+      fprintf (debug, "%s:", current_file);
+    if (debug_level & DEBUG_TRACE_LINE)
+      fprintf (debug, "%d:", current_line);
+  }
+  putc (' ', debug);
+}
+
+/* The rest of this file contains the functions for macro tracing output.
+   All tracing output for a macro call is collected on an obstack TRACE,
+   and printed whenever the line is complete.  This prevents tracing
+   output from interfering with other debug messages generated by the
+   various builtins.  */
+
+/*---------------------------------------------------------------------.
+| Tracing output is formatted here, by a simplified printf-to-obstack  |
+| function trace_format ().  Understands only %S, %s, %d, %l (optional |
+| left quote) and %r (optional right quote).			       |
+`---------------------------------------------------------------------*/
+
+static void
+trace_format (const char *fmt, ...)
+{
+  va_list args;
+  char ch;
+
+  int d;
+  char nbuf[32];
+  const char *s;
+  int slen;
+  int maxlen;
+
+  va_start (args, fmt);
+
+  while (true)
+    {
+      while ((ch = *fmt++) != '\0' && ch != '%')
+	obstack_1grow (&trace, ch);
+
+      if (ch == '\0')
+	break;
+
+      maxlen = 0;
+      switch (*fmt++)
+	{
+	case 'S':
+	  maxlen = max_debug_argument_length;
+	  /* fall through */
+
+	case 's':
+	  s = va_arg (args, const char *);
+	  break;
+
+	case 'l':
+	  s = (debug_level & DEBUG_TRACE_QUOTE) ? lquote.string : "";
+	  break;
+
+	case 'r':
+	  s = (debug_level & DEBUG_TRACE_QUOTE) ? rquote.string : "";
+	  break;
+
+	case 'd':
+	  d = va_arg (args, int);
+	  sprintf (nbuf, "%d", d);
+	  s = nbuf;
+	  break;
+
+	default:
+	  s = "";
+	  break;
+	}
+
+      slen = strlen (s);
+      if (maxlen == 0 || maxlen > slen)
+	obstack_grow (&trace, s, slen);
+      else
+	{
+	  obstack_grow (&trace, s, maxlen);
+	  obstack_grow (&trace, "...", 3);
+	}
+    }
+
+  va_end (args);
+}
+
+/*------------------------------------------------------------------.
+| Format the standard header attached to all tracing output lines.  |
+`------------------------------------------------------------------*/
+
+static void
+trace_header (int id)
+{
+  trace_format ("m4trace:");
+  if (current_line)
+    {
+      if (debug_level & DEBUG_TRACE_FILE)
+	trace_format ("%s:", current_file);
+      if (debug_level & DEBUG_TRACE_LINE)
+	trace_format ("%d:", current_line);
+    }
+  trace_format (" -%d- ", expansion_level);
+  if (debug_level & DEBUG_TRACE_CALLID)
+    trace_format ("id %d: ", id);
+}
+
+/*----------------------------------------------------.
+| Print current tracing line, and clear the obstack.  |
+`----------------------------------------------------*/
+
+static void
+trace_flush (void)
+{
+  char *line;
+
+  obstack_1grow (&trace, '\0');
+  line = (char *) obstack_finish (&trace);
+  DEBUG_PRINT1 ("%s\n", line);
+  obstack_free (&trace, line);
+}
+
+/*-------------------------------------------------------------.
+| Do pre-argument-collction tracing for macro NAME.  Used from |
+| expand_macro ().					       |
+`-------------------------------------------------------------*/
+
+void
+trace_prepre (const char *name, int id)
+{
+  trace_header (id);
+  trace_format ("%s ...", name);
+  trace_flush ();
+}
+
+/*-----------------------------------------------------------------------.
+| Format the parts of a trace line, that can be made before the macro is |
+| actually expanded.  Used from expand_macro ().			 |
+`-----------------------------------------------------------------------*/
+
+void
+trace_pre (const char *name, int id, int argc, token_data **argv)
+{
+  int i;
+  const builtin *bp;
+
+  trace_header (id);
+  trace_format ("%s", name);
+
+  if (argc > 1 && (debug_level & DEBUG_TRACE_ARGS))
+    {
+      trace_format ("(");
+
+      for (i = 1; i < argc; i++)
+	{
+	  if (i != 1)
+	    trace_format (", ");
+
+	  switch (TOKEN_DATA_TYPE (argv[i]))
+	    {
+	    case TOKEN_TEXT:
+	      trace_format ("%l%S%r", TOKEN_DATA_TEXT (argv[i]));
+	      break;
+
+	    case TOKEN_FUNC:
+	      bp = find_builtin_by_addr (TOKEN_DATA_FUNC (argv[i]));
+	      if (bp == NULL)
+		{
+		  M4ERROR ((warning_status, 0, "\
+INTERNAL ERROR: builtin not found in builtin table! (trace_pre ())"));
+		  abort ();
+		}
+	      trace_format ("<%s>", bp->name);
+	      break;
+
+	    default:
+	      M4ERROR ((warning_status, 0,
+			"INTERNAL ERROR: bad token data type (trace_pre ())"));
+	      abort ();
+	    }
+
+	}
+      trace_format (")");
+    }
+
+  if (debug_level & DEBUG_TRACE_CALL)
+    {
+      trace_format (" -> ???");
+      trace_flush ();
+    }
+}
+
+/*-------------------------------------------------------------------.
+| Format the final part of a trace line and print it all.  Used from |
+| expand_macro ().						     |
+`-------------------------------------------------------------------*/
+
+void
+trace_post (const char *name, int id, int argc, token_data **argv,
+	    const char *expanded)
+{
+  if (debug_level & DEBUG_TRACE_CALL)
+    {
+      trace_header (id);
+      trace_format ("%s%s", name, (argc > 1) ? "(...)" : "");
+    }
+
+  if (expanded && (debug_level & DEBUG_TRACE_EXPANSION))
+    trace_format (" -> %l%S%r", expanded);
+  trace_flush ();
+}
diff --git a/src/bin/m4/src/eval.c b/src/bin/m4/src/eval.c
new file mode 100644
index 0000000000..c2a55cbf7c
--- /dev/null
+++ b/src/bin/m4/src/eval.c
@@ -0,0 +1,799 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2006
+   Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* This file contains the functions to evaluate integer expressions for
+   the "eval" macro.  It is a little, fairly self-contained module, with
+   its own scanner, and a recursive descent parser.  The only entry point
+   is evaluate ().  For POSIX semantics of the "eval" macro, the type
+   eval_t must be a 32-bit signed integer.  */
+
+#include "m4.h"
+
+/* Evaluates token types.  */
+
+typedef enum eval_token
+  {
+    ERROR,
+    PLUS, MINUS,
+    EXPONENT,
+    TIMES, DIVIDE, MODULO,
+    EQ, NOTEQ, GT, GTEQ, LS, LSEQ,
+    LSHIFT, RSHIFT,
+    LNOT, LAND, LOR,
+    NOT, AND, OR, XOR,
+    LEFTP, RIGHTP,
+    NUMBER, EOTEXT
+  }
+eval_token;
+
+/* Error types.  */
+
+typedef enum eval_error
+  {
+    NO_ERROR,
+    MISSING_RIGHT,
+    SYNTAX_ERROR,
+    UNKNOWN_INPUT,
+    EXCESS_INPUT,
+    DIVIDE_ZERO,
+    MODULO_ZERO
+  }
+eval_error;
+
+static eval_error logical_or_term (eval_token, eval_t *);
+static eval_error logical_and_term (eval_token, eval_t *);
+static eval_error or_term (eval_token, eval_t *);
+static eval_error xor_term (eval_token, eval_t *);
+static eval_error and_term (eval_token, eval_t *);
+static eval_error not_term (eval_token, eval_t *);
+static eval_error logical_not_term (eval_token, eval_t *);
+static eval_error cmp_term (eval_token, eval_t *);
+static eval_error shift_term (eval_token, eval_t *);
+static eval_error add_term (eval_token, eval_t *);
+static eval_error mult_term (eval_token, eval_t *);
+static eval_error exp_term (eval_token, eval_t *);
+static eval_error unary_term (eval_token, eval_t *);
+static eval_error simple_term (eval_token, eval_t *);
+
+/*--------------------.
+| Lexical functions.  |
+`--------------------*/
+
+/* Pointer to next character of input text.  */
+static const char *eval_text;
+
+/* Value of eval_text, from before last call of eval_lex ().  This is so we
+   can back up, if we have read too much.  */
+static const char *last_text;
+
+static void
+eval_init_lex (const char *text)
+{
+  eval_text = text;
+  last_text = NULL;
+}
+
+static void
+eval_undo (void)
+{
+  eval_text = last_text;
+}
+
+/* VAL is numerical value, if any.  */
+
+static eval_token
+eval_lex (eval_t *val)
+{
+  while (isspace (to_uchar (*eval_text)))
+    eval_text++;
+
+  last_text = eval_text;
+
+  if (*eval_text == '\0')
+    return EOTEXT;
+
+  if (isdigit (to_uchar (*eval_text)))
+    {
+      int base, digit;
+
+      if (*eval_text == '0')
+	{
+	  eval_text++;
+	  switch (*eval_text)
+	    {
+	    case 'x':
+	    case 'X':
+	      base = 16;
+	      eval_text++;
+	      break;
+
+	    case 'b':
+	    case 'B':
+	      base = 2;
+	      eval_text++;
+	      break;
+
+	    case 'r':
+	    case 'R':
+	      base = 0;
+	      eval_text++;
+	      while (isdigit (to_uchar (*eval_text)) && base <= 36)
+		base = 10 * base + *eval_text++ - '0';
+	      if (base == 0 || base > 36 || *eval_text != ':')
+		return ERROR;
+	      eval_text++;
+	      break;
+
+	    default:
+	      base = 8;
+	    }
+	}
+      else
+	base = 10;
+
+      (*val) = 0;
+      for (; *eval_text; eval_text++)
+	{
+	  if (isdigit (to_uchar (*eval_text)))
+	    digit = *eval_text - '0';
+	  else if (islower (to_uchar (*eval_text)))
+	    digit = *eval_text - 'a' + 10;
+	  else if (isupper (to_uchar (*eval_text)))
+	    digit = *eval_text - 'A' + 10;
+	  else
+	    break;
+
+	  if (base == 1)
+	    {
+	      if (digit == 1)
+		(*val)++;
+	      else if (digit == 0 && !*val)
+		continue;
+	      else
+		break;
+	    }
+	  else if (digit >= base)
+	    break;
+	  else
+	    (*val) = (*val) * base + digit;
+	}
+      return NUMBER;
+    }
+
+  switch (*eval_text++)
+    {
+    case '+':
+      return PLUS;
+    case '-':
+      return MINUS;
+    case '*':
+      if (*eval_text == '*')
+	{
+	  eval_text++;
+	  return EXPONENT;
+	}
+      else
+	return TIMES;
+    case '/':
+      return DIVIDE;
+    case '%':
+      return MODULO;
+    case '=':
+      if (*eval_text == '=')
+	eval_text++;
+      return EQ;
+    case '!':
+      if (*eval_text == '=')
+	{
+	  eval_text++;
+	  return NOTEQ;
+	}
+      else
+	return LNOT;
+    case '>':
+      if (*eval_text == '=')
+	{
+	  eval_text++;
+	  return GTEQ;
+	}
+      else if (*eval_text == '>')
+	{
+	  eval_text++;
+	  return RSHIFT;
+	}
+      else
+	return GT;
+    case '<':
+      if (*eval_text == '=')
+	{
+	  eval_text++;
+	  return LSEQ;
+	}
+      else if (*eval_text == '<')
+	{
+	  eval_text++;
+	  return LSHIFT;
+	}
+      else
+	return LS;
+    case '^':
+      return XOR;
+    case '~':
+      return NOT;
+    case '&':
+      if (*eval_text == '&')
+	{
+	  eval_text++;
+	  return LAND;
+	}
+      else
+	return AND;
+    case '|':
+      if (*eval_text == '|')
+	{
+	  eval_text++;
+	  return LOR;
+	}
+      else
+	return OR;
+    case '(':
+      return LEFTP;
+    case ')':
+      return RIGHTP;
+    default:
+      return ERROR;
+    }
+}
+
+/*---------------------------------------.
+| Main entry point, called from "eval".	 |
+`---------------------------------------*/
+
+bool
+evaluate (const char *expr, eval_t *val)
+{
+  eval_token et;
+  eval_error err;
+
+  eval_init_lex (expr);
+  et = eval_lex (val);
+  err = logical_or_term (et, val);
+
+  if (err == NO_ERROR && *eval_text != '\0')
+    err = EXCESS_INPUT;
+
+  switch (err)
+    {
+    case NO_ERROR:
+      break;
+
+    case MISSING_RIGHT:
+      M4ERROR ((warning_status, 0,
+		"bad expression in eval (missing right parenthesis): %s",
+		expr));
+      break;
+
+    case SYNTAX_ERROR:
+      M4ERROR ((warning_status, 0,
+		"bad expression in eval: %s", expr));
+      break;
+
+    case UNKNOWN_INPUT:
+      M4ERROR ((warning_status, 0,
+		"bad expression in eval (bad input): %s", expr));
+      break;
+
+    case EXCESS_INPUT:
+      M4ERROR ((warning_status, 0,
+		"bad expression in eval (excess input): %s", expr));
+      break;
+
+    case DIVIDE_ZERO:
+      M4ERROR ((warning_status, 0,
+		"divide by zero in eval: %s", expr));
+      break;
+
+    case MODULO_ZERO:
+      M4ERROR ((warning_status, 0,
+		"modulo by zero in eval: %s", expr));
+      break;
+
+    default:
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: bad error code in evaluate ()"));
+      abort ();
+    }
+
+  return err != NO_ERROR;
+}
+
+/*---------------------------.
+| Recursive descent parser.  |
+`---------------------------*/
+
+static eval_error
+logical_or_term (eval_token et, eval_t *v1)
+{
+  eval_t v2;
+  eval_error er;
+
+  if ((er = logical_and_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((et = eval_lex (&v2)) == LOR)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = logical_and_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      *v1 = *v1 || v2;
+    }
+  if (et == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+logical_and_term (eval_token et, eval_t *v1)
+{
+  eval_t v2;
+  eval_error er;
+
+  if ((er = or_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((et = eval_lex (&v2)) == LAND)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = or_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      *v1 = *v1 && v2;
+    }
+  if (et == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+or_term (eval_token et, eval_t *v1)
+{
+  eval_t v2;
+  eval_error er;
+
+  if ((er = xor_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((et = eval_lex (&v2)) == OR)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = xor_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      *v1 = *v1 | v2;
+    }
+  if (et == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+xor_term (eval_token et, eval_t *v1)
+{
+  eval_t v2;
+  eval_error er;
+
+  if ((er = and_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((et = eval_lex (&v2)) == XOR)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = and_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      *v1 = *v1 ^ v2;
+    }
+  if (et == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+and_term (eval_token et, eval_t *v1)
+{
+  eval_t v2;
+  eval_error er;
+
+  if ((er = not_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((et = eval_lex (&v2)) == AND)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = not_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      *v1 = *v1 & v2;
+    }
+  if (et == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+not_term (eval_token et, eval_t *v1)
+{
+  eval_error er;
+
+  if (et == NOT)
+    {
+      et = eval_lex (v1);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = not_term (et, v1)) != NO_ERROR)
+	return er;
+      *v1 = ~*v1;
+    }
+  else
+    if ((er = logical_not_term (et, v1)) != NO_ERROR)
+      return er;
+
+  return NO_ERROR;
+}
+
+static eval_error
+logical_not_term (eval_token et, eval_t *v1)
+{
+  eval_error er;
+
+  if (et == LNOT)
+    {
+      et = eval_lex (v1);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = logical_not_term (et, v1)) != NO_ERROR)
+	return er;
+      *v1 = !*v1;
+    }
+  else
+    if ((er = cmp_term (et, v1)) != NO_ERROR)
+      return er;
+
+  return NO_ERROR;
+}
+
+static eval_error
+cmp_term (eval_token et, eval_t *v1)
+{
+  eval_token op;
+  eval_t v2;
+  eval_error er;
+
+  if ((er = shift_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((op = eval_lex (&v2)) == EQ || op == NOTEQ
+	 || op == GT || op == GTEQ
+	 || op == LS || op == LSEQ)
+    {
+
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = shift_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      switch (op)
+	{
+	case EQ:
+	  *v1 = *v1 == v2;
+	  break;
+
+	case NOTEQ:
+	  *v1 = *v1 != v2;
+	  break;
+
+	case GT:
+	  *v1 = *v1 > v2;
+	  break;
+
+	case GTEQ:
+	  *v1 = *v1 >= v2;
+	  break;
+
+	case LS:
+	  *v1 = *v1 < v2;
+	  break;
+
+	case LSEQ:
+	  *v1 = *v1 <= v2;
+	  break;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: bad comparison operator in cmp_term ()"));
+	  abort ();
+	}
+    }
+  if (op == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+shift_term (eval_token et, eval_t *v1)
+{
+  eval_token op;
+  eval_t v2;
+  eval_error er;
+
+  if ((er = add_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((op = eval_lex (&v2)) == LSHIFT || op == RSHIFT)
+    {
+
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = add_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      /* Shifting by a negative number, or by greater than the width, is
+	 undefined in C, but POSIX requires eval to operate on 32-bit signed
+	 numbers.  Explicitly mask the right argument to ensure defined
+	 behavior.  */
+      switch (op)
+	{
+	case LSHIFT:
+	  *v1 = *v1 << (v2 & 0x1f);
+	  break;
+
+	case RSHIFT:
+	  /* This assumes 2's-complement with sign-extension, since shifting
+	     a negative number right is implementation-defined in C.  */
+	  *v1 = *v1 >> (v2 & 0x1f);
+	  break;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: bad shift operator in shift_term ()"));
+	  abort ();
+	}
+    }
+  if (op == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+add_term (eval_token et, eval_t *v1)
+{
+  eval_token op;
+  eval_t v2;
+  eval_error er;
+
+  if ((er = mult_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((op = eval_lex (&v2)) == PLUS || op == MINUS)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = mult_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      if (op == PLUS)
+	*v1 = *v1 + v2;
+      else
+	*v1 = *v1 - v2;
+    }
+  if (op == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+mult_term (eval_token et, eval_t *v1)
+{
+  eval_token op;
+  eval_t v2;
+  eval_error er;
+
+  if ((er = exp_term (et, v1)) != NO_ERROR)
+    return er;
+
+  while ((op = eval_lex (&v2)) == TIMES || op == DIVIDE || op == MODULO)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = exp_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      switch (op)
+	{
+	case TIMES:
+	  *v1 = *v1 * v2;
+	  break;
+
+	case DIVIDE:
+	  if (v2 == 0)
+	    return DIVIDE_ZERO;
+	  else if (v2 == -1)
+	    /* Avoid the x86 SIGFPE on INT_MIN / -1.  */
+	    *v1 = -*v1;
+	  else
+	    *v1 = *v1 / v2;
+	  break;
+
+	case MODULO:
+	  if (v2 == 0)
+	    return MODULO_ZERO;
+	  else if (v2 == -1)
+	    /* Avoid the x86 SIGFPE on INT_MIN % -1.  */
+	    *v1 = 0;
+	  else
+	    *v1 = *v1 % v2;
+	  break;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: bad operator in mult_term ()"));
+	  abort ();
+	}
+    }
+  if (op == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+exp_term (eval_token et, eval_t *v1)
+{
+  register eval_t result;
+  eval_t v2;
+  eval_error er;
+
+  if ((er = unary_term (et, v1)) != NO_ERROR)
+    return er;
+  result = *v1;
+
+  while ((et = eval_lex (&v2)) == EXPONENT)
+    {
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = exp_term (et, &v2)) != NO_ERROR)
+	return er;
+
+      result = 1;
+      while (v2-- > 0)
+	result *= *v1;
+      *v1 = result;
+    }
+  if (et == ERROR)
+    return UNKNOWN_INPUT;
+
+  eval_undo ();
+  return NO_ERROR;
+}
+
+static eval_error
+unary_term (eval_token et, eval_t *v1)
+{
+  eval_token et2 = et;
+  eval_error er;
+
+  if (et == PLUS || et == MINUS)
+    {
+      et2 = eval_lex (v1);
+      if (et2 == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = simple_term (et2, v1)) != NO_ERROR)
+	return er;
+
+      if (et == MINUS)
+	*v1 = -*v1;
+    }
+  else
+    if ((er = simple_term (et, v1)) != NO_ERROR)
+      return er;
+
+  return NO_ERROR;
+}
+
+static eval_error
+simple_term (eval_token et, eval_t *v1)
+{
+  eval_t v2;
+  eval_error er;
+
+  switch (et)
+    {
+    case LEFTP:
+      et = eval_lex (v1);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if ((er = logical_or_term (et, v1)) != NO_ERROR)
+	return er;
+
+      et = eval_lex (&v2);
+      if (et == ERROR)
+	return UNKNOWN_INPUT;
+
+      if (et != RIGHTP)
+	return MISSING_RIGHT;
+
+      break;
+
+    case NUMBER:
+      break;
+
+    default:
+      return SYNTAX_ERROR;
+    }
+  return NO_ERROR;
+}
diff --git a/src/bin/m4/src/format.c b/src/bin/m4/src/format.c
new file mode 100644
index 0000000000..2482041521
--- /dev/null
+++ b/src/bin/m4/src/format.c
@@ -0,0 +1,298 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2006
+   Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* printf like formatting for m4.  */
+
+#include "m4.h"
+#include "xvasprintf.h"
+
+/* Simple varargs substitute.  */
+
+#define ARG_INT(argc, argv) \
+	((argc == 0) ? 0 : \
+	 (--argc, argv++, atoi (TOKEN_DATA_TEXT (argv[-1]))))
+
+#define ARG_UINT(argc, argv) \
+	((argc == 0) ? 0 : \
+	 (--argc, argv++, (unsigned int) atoi (TOKEN_DATA_TEXT (argv[-1]))))
+
+#define ARG_LONG(argc, argv) \
+	((argc == 0) ? 0 : \
+	 (--argc, argv++, atol (TOKEN_DATA_TEXT (argv[-1]))))
+
+#define ARG_ULONG(argc, argv) \
+	((argc == 0) ? 0 : \
+	 (--argc, argv++, (unsigned long) atol (TOKEN_DATA_TEXT (argv[-1]))))
+
+#define ARG_STR(argc, argv) \
+	((argc == 0) ? "" : \
+	 (--argc, argv++, TOKEN_DATA_TEXT (argv[-1])))
+
+#define ARG_DOUBLE(argc, argv) \
+	((argc == 0) ? 0 : \
+	 (--argc, argv++, atof (TOKEN_DATA_TEXT (argv[-1]))))
+
+
+/*------------------------------------------------------------------------.
+| The main formatting function.  Output is placed on the obstack OBS, the |
+| first argument in ARGV is the formatting string, and the rest is	  |
+| arguments for the string.						  |
+`------------------------------------------------------------------------*/
+
+void
+format (struct obstack *obs, int argc, token_data **argv)
+{
+  char *fmt;			/* format control string */
+  const char *fstart;		/* beginning of current format spec */
+  int c;			/* a simple character */
+
+  /* Flags.  */
+  char flags;			/* 1 iff treating flags */
+
+  /* Precision specifiers.  */
+  int width;			/* minimum field width */
+  int prec;			/* precision */
+  char lflag;			/* long flag */
+  char hflag;			/* short flag */
+
+  /* Buffer and stuff.  */
+  char *str;			/* malloc'd buffer of formatted text */
+  enum {INT, UINT, LONG, ULONG, DOUBLE, STR} datatype;
+
+  fmt = (char *) ARG_STR (argc, argv);
+  for (;;)
+    {
+      while ((c = *fmt++) != '%')
+	{
+	  if (c == 0)
+	    return;
+	  obstack_1grow (obs, c);
+	}
+
+      fstart = fmt - 1;
+
+      if (*fmt == '%')
+	{
+	  obstack_1grow (obs, '%');
+	  fmt++;
+	  continue;
+	}
+
+      /* Parse flags.  */
+      flags = 1;
+      do
+	{
+	  switch (*fmt)
+	    {
+	    case '-':		/* left justification */
+	    case '+':		/* mandatory sign */
+	    case ' ':		/* space instead of positive sign */
+	    case '0':		/* zero padding */
+	    case '#':		/* alternate output */
+	      break;
+
+	    default:
+	      flags = 0;
+	      break;
+	    }
+	}
+      while (flags && fmt++);
+
+      /* Minimum field width.  */
+      width = -1;
+      if (*fmt == '*')
+	{
+	  width = ARG_INT (argc, argv);
+	  fmt++;
+	}
+      else if (isdigit (to_uchar (*fmt)))
+	{
+	  do
+	    {
+	      fmt++;
+	    }
+	  while (isdigit (to_uchar (*fmt)));
+	}
+
+      /* Maximum precision.  */
+      prec = -1;
+      if (*fmt == '.')
+	{
+	  if (*(++fmt) == '*')
+	    {
+	      prec = ARG_INT (argc, argv);
+	      ++fmt;
+	    }
+	  else if (isdigit (to_uchar (*fmt)))
+	    {
+	      do
+		{
+		  fmt++;
+		}
+	      while (isdigit (to_uchar (*fmt)));
+	    }
+	}
+
+      /* Length modifiers.  */
+      lflag = (*fmt == 'l');
+      hflag = (*fmt == 'h');
+      if (lflag || hflag)
+	fmt++;
+
+      switch (*fmt++)
+	{
+
+	case '\0':
+	  return;
+
+	case 'c':
+	  datatype = INT;
+	  break;
+
+	case 's':
+	  datatype = STR;
+	  break;
+
+	case 'd':
+	case 'i':
+	  if (lflag)
+	    {
+	      datatype = LONG;
+	    }
+	  else
+	    {
+	      datatype = INT;
+	    }
+	  break;
+
+	case 'o':
+	case 'x':
+	case 'X':
+	case 'u':
+	  if (lflag)
+	    {
+	      datatype = ULONG;
+	    }
+	  else
+	    {
+	      datatype = UINT;
+	    }
+	  break;
+
+	case 'e':
+	case 'E':
+	case 'f':
+	case 'F':
+	case 'g':
+	case 'G':
+	  datatype = DOUBLE;
+	  break;
+
+	default:
+	  continue;
+	}
+
+      c = *fmt;
+      *fmt = '\0';
+
+      switch(datatype)
+	{
+	case INT:
+	  if (width != -1 && prec != -1)
+	    str = xasprintf (fstart, width, prec, ARG_INT(argc, argv));
+	  else if (width != -1)
+	    str = xasprintf (fstart, width, ARG_INT(argc, argv));
+	  else if (prec != -1)
+	    str = xasprintf (fstart, prec, ARG_INT(argc, argv));
+	  else
+	    str = xasprintf (fstart, ARG_INT(argc, argv));
+	  break;
+
+	case UINT:
+	  if (width != -1 && prec != -1)
+	    str = xasprintf (fstart, width, prec, ARG_UINT(argc, argv));
+	  else if (width != -1)
+	    str = xasprintf (fstart, width, ARG_UINT(argc, argv));
+	  else if (prec != -1)
+	    str = xasprintf (fstart, prec, ARG_UINT(argc, argv));
+	  else
+	    str = xasprintf (fstart, ARG_UINT(argc, argv));
+	  break;
+
+	case LONG:
+	  if (width != -1 && prec != -1)
+	    str = xasprintf (fstart, width, prec, ARG_LONG(argc, argv));
+	  else if (width != -1)
+	    str = xasprintf (fstart, width, ARG_LONG(argc, argv));
+	  else if (prec != -1)
+	    str = xasprintf (fstart, prec, ARG_LONG(argc, argv));
+	  else
+	    str = xasprintf (fstart, ARG_LONG(argc, argv));
+	  break;
+
+	case ULONG:
+	  if (width != -1 && prec != -1)
+	    str = xasprintf (fstart, width, prec, ARG_ULONG(argc, argv));
+	  else if (width != -1)
+	    str = xasprintf (fstart, width, ARG_ULONG(argc, argv));
+	  else if (prec != -1)
+	    str = xasprintf (fstart, prec, ARG_ULONG(argc, argv));
+	  else
+	    str = xasprintf (fstart, ARG_ULONG(argc, argv));
+	  break;
+
+	case DOUBLE:
+	  if (width != -1 && prec != -1)
+	    str = xasprintf (fstart, width, prec, ARG_DOUBLE(argc, argv));
+	  else if (width != -1)
+	    str = xasprintf (fstart, width, ARG_DOUBLE(argc, argv));
+	  else if (prec != -1)
+	    str = xasprintf (fstart, prec, ARG_DOUBLE(argc, argv));
+	  else
+	    str = xasprintf (fstart, ARG_DOUBLE(argc, argv));
+	  break;
+
+	case STR:
+	  if (width != -1 && prec != -1)
+	    str = xasprintf (fstart, width, prec, ARG_STR(argc, argv));
+	  else if (width != -1)
+	    str = xasprintf (fstart, width, ARG_STR(argc, argv));
+	  else if (prec != -1)
+	    str = xasprintf (fstart, prec, ARG_STR(argc, argv));
+	  else
+	    str = xasprintf (fstart, ARG_STR(argc, argv));
+	  break;
+
+	default:
+	  abort();
+	}
+
+      *fmt = c;
+
+      /* NULL was returned on failure, such as invalid format string.  For
+	 now, just silently ignore that bad specifier.  */
+      if (str == NULL)
+	continue;
+
+      obstack_grow (obs, str, strlen (str));
+      free (str);
+    }
+}
diff --git a/src/bin/m4/src/freeze.c b/src/bin/m4/src/freeze.c
new file mode 100644
index 0000000000..7b8a7bc30c
--- /dev/null
+++ b/src/bin/m4/src/freeze.c
@@ -0,0 +1,379 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2006
+   Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* This module handles frozen files.  */
+
+#include "m4.h"
+
+/*-------------------------------------------------------------------.
+| Destructively reverse a symbol list and return the reversed list.  |
+`-------------------------------------------------------------------*/
+
+static symbol *
+reverse_symbol_list (symbol *sym)
+{
+  symbol *result;
+  symbol *next;
+
+  result = NULL;
+  while (sym)
+    {
+      next = SYMBOL_NEXT (sym);
+      SYMBOL_NEXT (sym) = result;
+      result = sym;
+      sym = next;
+    }
+  return result;
+}
+
+/*------------------------------------------------.
+| Produce a frozen state to the given file NAME.  |
+`------------------------------------------------*/
+
+void
+produce_frozen_state (const char *name)
+{
+  FILE *file;
+  int h;
+  symbol *sym;
+  const builtin *bp;
+
+  if (file = fopen (name, O_BINARY ? "wb" : "w"), !file)
+    {
+      M4ERROR ((warning_status, errno, name));
+      return;
+    }
+
+  /* Write a recognizable header.  */
+
+  fprintf (file, "# This is a frozen state file generated by %s\n",
+	   PACKAGE_STRING);
+  fprintf (file, "V1\n");
+
+  /* Dump quote delimiters.  */
+
+  if (strcmp (lquote.string, DEF_LQUOTE) || strcmp (rquote.string, DEF_RQUOTE))
+    {
+      fprintf (file, "Q%d,%d\n", (int) lquote.length, (int) rquote.length);
+      fputs (lquote.string, file);
+      fputs (rquote.string, file);
+      fputc ('\n', file);
+    }
+
+  /* Dump comment delimiters.  */
+
+  if (strcmp (bcomm.string, DEF_BCOMM) || strcmp (ecomm.string, DEF_ECOMM))
+    {
+      fprintf (file, "C%d,%d\n", (int) bcomm.length, (int) ecomm.length);
+      fputs (bcomm.string, file);
+      fputs (ecomm.string, file);
+      fputc ('\n', file);
+    }
+
+  /* Dump all symbols.  */
+
+  for (h = 0; h < hash_table_size; h++)
+    {
+
+      /* Process all entries in one bucket, from the last to the first.
+	 This order ensures that, at reload time, pushdef's will be
+	 executed with the oldest definitions first.  */
+
+      symtab[h] = reverse_symbol_list (symtab[h]);
+      for (sym = symtab[h]; sym; sym = SYMBOL_NEXT (sym))
+	{
+	  switch (SYMBOL_TYPE (sym))
+	    {
+	    case TOKEN_TEXT:
+	      fprintf (file, "T%d,%d\n",
+		       (int) strlen (SYMBOL_NAME (sym)),
+		       (int) strlen (SYMBOL_TEXT (sym)));
+	      fputs (SYMBOL_NAME (sym), file);
+	      fputs (SYMBOL_TEXT (sym), file);
+	      fputc ('\n', file);
+	      break;
+
+	    case TOKEN_FUNC:
+	      bp = find_builtin_by_addr (SYMBOL_FUNC (sym));
+	      if (bp == NULL)
+		{
+		  M4ERROR ((warning_status, 0, "\
+INTERNAL ERROR: builtin not found in builtin table!"));
+		  abort ();
+		}
+	      fprintf (file, "F%d,%d\n",
+		       (int) strlen (SYMBOL_NAME (sym)),
+		       (int) strlen (bp->name));
+	      fputs (SYMBOL_NAME (sym), file);
+	      fputs (bp->name, file);
+	      fputc ('\n', file);
+	      break;
+
+	    default:
+	      M4ERROR ((warning_status, 0, "\
+INTERNAL ERROR: bad token data type in freeze_one_symbol ()"));
+	      abort ();
+	      break;
+	    }
+	}
+
+      /* Reverse the bucket once more, putting it back as it was.  */
+
+      symtab[h] = reverse_symbol_list (symtab[h]);
+    }
+
+  /* Let diversions be issued from output.c module, its cleaner to have this
+     piece of code there.  */
+
+  freeze_diversions (file);
+
+  /* All done.  */
+
+  fputs ("# End of frozen state file\n", file);
+  if (close_stream (file) != 0)
+    M4ERROR ((EXIT_FAILURE, errno, "unable to create frozen state"));
+}
+
+/*----------------------------------------------------------------------.
+| Issue a message saying that some character is an EXPECTED character.  |
+`----------------------------------------------------------------------*/
+
+static void
+issue_expect_message (int expected)
+{
+  if (expected == '\n')
+    M4ERROR ((EXIT_FAILURE, 0, "expecting line feed in frozen file"));
+  else
+    M4ERROR ((EXIT_FAILURE, 0, "expecting character `%c' in frozen file",
+	      expected));
+}
+
+/*-------------------------------------------------.
+| Reload a frozen state from the given file NAME.  |
+`-------------------------------------------------*/
+
+/* We are seeking speed, here.  */
+
+void
+reload_frozen_state (const char *name)
+{
+  FILE *file;
+  int character;
+  int operation;
+  char *string[2];
+  int allocated[2];
+  int number[2];
+  const builtin *bp;
+
+#define GET_CHARACTER \
+  (character = getc (file))
+
+#define GET_NUMBER(Number) \
+  do								\
+    {								\
+      (Number) = 0;						\
+      while (isdigit (character))				\
+	{							\
+	  (Number) = 10 * (Number) + character - '0';		\
+	  GET_CHARACTER;					\
+	}							\
+    }								\
+  while (0)
+
+#define VALIDATE(Expected) \
+  do								\
+    {								\
+      if (character != (Expected))				\
+	issue_expect_message ((Expected));			\
+    }								\
+  while (0)
+
+  /* Skip comments (`#' at beginning of line) and blank lines, setting
+     character to the next directive or to EOF.  */
+
+#define GET_DIRECTIVE \
+  do                                                            \
+    {                                                           \
+      GET_CHARACTER;                                            \
+      if (character == '#')                                     \
+        {                                                       \
+          while (character != EOF && character != '\n')         \
+            GET_CHARACTER;                                      \
+          VALIDATE ('\n');                                      \
+        }                                                       \
+    }                                                           \
+  while (character == '\n')
+
+  file = m4_path_search (name, NULL);
+  if (file == NULL)
+    M4ERROR ((EXIT_FAILURE, errno, "cannot open %s", name));
+
+  allocated[0] = 100;
+  string[0] = xcharalloc ((size_t) allocated[0]);
+  allocated[1] = 100;
+  string[1] = xcharalloc ((size_t) allocated[1]);
+
+  /* Validate format version.  Only `1' is acceptable for now.  */
+  GET_DIRECTIVE;
+  VALIDATE ('V');
+  GET_CHARACTER;
+  GET_NUMBER (number[0]);
+  if (number[0] > 1)
+    M4ERROR ((EXIT_MISMATCH, 0,
+              "frozen file version %d greater than max supported of 1",
+	      number[0]));
+  else if (number[0] < 1)
+    M4ERROR ((EXIT_FAILURE, 0,
+              "ill-formed frozen file, version directive expected"));
+  VALIDATE ('\n');
+
+  GET_DIRECTIVE;
+  while (character != EOF)
+    {
+      switch (character)
+        {
+        default:
+          M4ERROR ((EXIT_FAILURE, 0, "ill-formed frozen file"));
+
+        case 'C':
+        case 'D':
+        case 'F':
+        case 'T':
+        case 'Q':
+          operation = character;
+          GET_CHARACTER;
+
+          /* Get string lengths.  Accept a negative diversion number.  */
+
+          if (operation == 'D' && character == '-')
+            {
+              GET_CHARACTER;
+              GET_NUMBER (number[0]);
+              number[0] = -number[0];
+            }
+          else
+            GET_NUMBER (number[0]);
+          VALIDATE (',');
+          GET_CHARACTER;
+          GET_NUMBER (number[1]);
+          VALIDATE ('\n');
+
+          if (operation != 'D')
+            {
+
+              /* Get first string contents.  */
+
+              if (number[0] + 1 > allocated[0])
+                {
+                  free (string[0]);
+                  allocated[0] = number[0] + 1;
+                  string[0] = xcharalloc ((size_t) allocated[0]);
+                }
+
+              if (number[0] > 0)
+                if (!fread (string[0], (size_t) number[0], 1, file))
+                  M4ERROR ((EXIT_FAILURE, 0, "premature end of frozen file"));
+
+              string[0][number[0]] = '\0';
+            }
+
+          /* Get second string contents.  */
+
+          if (number[1] + 1 > allocated[1])
+            {
+              free (string[1]);
+              allocated[1] = number[1] + 1;
+              string[1] = xcharalloc ((size_t) allocated[1]);
+            }
+
+          if (number[1] > 0)
+            if (!fread (string[1], (size_t) number[1], 1, file))
+              M4ERROR ((EXIT_FAILURE, 0, "premature end of frozen file"));
+
+          string[1][number[1]] = '\0';
+          GET_CHARACTER;
+          VALIDATE ('\n');
+
+          /* Act according to operation letter.  */
+
+          switch (operation)
+            {
+            case 'C':
+
+              /* Change comment strings.  */
+
+              set_comment (string[0], string[1]);
+              break;
+
+            case 'D':
+
+              /* Select a diversion and add a string to it.  */
+
+              make_diversion (number[0]);
+              if (number[1] > 0)
+                shipout_text (NULL, string[1], number[1]);
+              break;
+
+            case 'F':
+
+              /* Enter a macro having a builtin function as a definition.  */
+
+              bp = find_builtin_by_name (string[1]);
+              define_builtin (string[0], bp, SYMBOL_PUSHDEF);
+              break;
+
+            case 'T':
+
+              /* Enter a macro having an expansion text as a definition.  */
+
+              define_user_macro (string[0], string[1], SYMBOL_PUSHDEF);
+              break;
+
+            case 'Q':
+
+              /* Change quote strings.  */
+
+              set_quotes (string[0], string[1]);
+              break;
+
+            default:
+
+              /* Cannot happen.  */
+
+              break;
+            }
+          break;
+
+        }
+      GET_DIRECTIVE;
+    }
+
+  free (string[0]);
+  free (string[1]);
+  errno = 0;
+  if (ferror (file) || fclose (file) != 0)
+    M4ERROR ((EXIT_FAILURE, errno, "unable to read frozen state"));
+
+#undef GET_CHARACTER
+#undef GET_DIRECTIVE
+#undef GET_NUMBER
+#undef VALIDATE
+}
diff --git a/src/bin/m4/src/input.c b/src/bin/m4/src/input.c
new file mode 100644
index 0000000000..6296281bf6
--- /dev/null
+++ b/src/bin/m4/src/input.c
@@ -0,0 +1,1129 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006
+   Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* Handling of different input sources, and lexical analysis.  */
+
+#include "m4.h"
+
+/* Unread input can be either files, that should be read (eg. included
+   files), strings, which should be rescanned (eg. macro expansion text),
+   or quoted macro definitions (as returned by the builtin "defn").
+   Unread input are organised in a stack, implemented with an obstack.
+   Each input source is described by a "struct input_block".  The obstack
+   is "current_input".  The top of the input stack is "isp".
+
+   The macro "m4wrap" places the text to be saved on another input
+   stack, on the obstack "wrapup_stack", whose top is "wsp".  When EOF
+   is seen on normal input (eg, when "current_input" is empty), input is
+   switched over to "wrapup_stack", and the original "current_input" is
+   freed.  A new stack is allocated for "wrapup_stack", which will
+   accept any text produced by calls to "m4wrap" from within the
+   wrapped text.  This process of shuffling "wrapup_stack" to
+   "current_input" can continue indefinitely, even generating infinite
+   loops (e.g. "define(`f',`m4wrap(`f')')f"), without memory leaks.
+
+   Pushing new input on the input stack is done by push_file (),
+   push_string (), push_wrapup () (for wrapup text), and push_macro ()
+   (for macro definitions).  Because macro expansion needs direct access
+   to the current input obstack (for optimisation), push_string () are
+   split in two functions, push_string_init (), which returns a pointer
+   to the current input stack, and push_string_finish (), which return a
+   pointer to the final text.  The input_block *next is used to manage
+   the coordination between the different push routines.
+
+   The current file and line number are stored in two global
+   variables, for use by the error handling functions in m4.c.  Macro
+   expansion wants to report the line where a macro name was detected,
+   rather than where it finished collecting arguments.  This also
+   applies to text resulting from macro expansions.  So each input
+   block maintains its own notion of the current file and line, and
+   swapping between input blocks updates the global variables
+   accordingly.  */
+
+#ifdef ENABLE_CHANGEWORD
+#include "regex.h"
+#endif
+
+enum input_type
+{
+  INPUT_STRING,		/* String resulting from macro expansion.  */
+  INPUT_FILE,		/* File from command line or include.  */
+  INPUT_MACRO		/* Builtin resulting from defn.  */
+};
+
+typedef enum input_type input_type;
+
+struct input_block
+{
+  struct input_block *prev;	/* previous input_block on the input stack */
+  input_type type;		/* see enum values */
+  const char *file;		/* file where this input is from */
+  int line;			/* line where this input is from */
+  union
+    {
+      struct
+	{
+	  char *string;		/* remaining string value */
+	}
+	u_s;	/* INPUT_STRING */
+      struct
+	{
+	  FILE *fp;		/* input file handle */
+	  bool end : 1;		/* true if peek has seen EOF */
+	  bool close : 1;	/* true if we should close file on pop */
+	  bool advance_line : 1; /* track previous start_of_input_line */
+	}
+	u_f;	/* INPUT_FILE */
+      builtin_func *func;	/* pointer to macro's function */
+    }
+  u;
+};
+
+typedef struct input_block input_block;
+
+
+/* Current input file name.  */
+const char *current_file;
+
+/* Current input line number.  */
+int current_line;
+
+/* Obstack for storing individual tokens.  */
+static struct obstack token_stack;
+
+/* Obstack for storing file names.  */
+static struct obstack file_names;
+
+/* Wrapup input stack.  */
+static struct obstack *wrapup_stack;
+
+/* Current stack, from input or wrapup.  */
+static struct obstack *current_input;
+
+/* Bottom of token_stack, for obstack_free.  */
+static void *token_bottom;
+
+/* Pointer to top of current_input.  */
+static input_block *isp;
+
+/* Pointer to top of wrapup_stack.  */
+static input_block *wsp;
+
+/* Aux. for handling split push_string ().  */
+static input_block *next;
+
+/* Flag for next_char () to increment current_line.  */
+static bool start_of_input_line;
+
+/* Flag for next_char () to recognize change in input block.  */
+static bool input_change;
+
+#define CHAR_EOF	256	/* character return on EOF */
+#define CHAR_MACRO	257	/* character return for MACRO token */
+
+/* Quote chars.  */
+STRING rquote;
+STRING lquote;
+
+/* Comment chars.  */
+STRING bcomm;
+STRING ecomm;
+
+#ifdef ENABLE_CHANGEWORD
+
+# define DEFAULT_WORD_REGEXP "[_a-zA-Z][_a-zA-Z0-9]*"
+
+static char *word_start;
+static struct re_pattern_buffer word_regexp;
+static int default_word_regexp;
+static struct re_registers regs;
+
+#else /* ! ENABLE_CHANGEWORD */
+# define default_word_regexp 1
+#endif /* ! ENABLE_CHANGEWORD */
+
+#ifdef DEBUG_INPUT
+static const char *token_type_string (token_type);
+#endif
+
+
+/*-------------------------------------------------------------------.
+| push_file () pushes an input file on the input stack, saving the   |
+| current file name and line number.  If next is non-NULL, this push |
+| invalidates a call to push_string_init (), whose storage is        |
+| consequently released.  If CLOSE, then close FP after EOF is       |
+| detected.                                                          |
+`-------------------------------------------------------------------*/
+
+void
+push_file (FILE *fp, const char *title, bool close)
+{
+  input_block *i;
+
+  if (next != NULL)
+    {
+      obstack_free (current_input, next);
+      next = NULL;
+    }
+
+  if (debug_level & DEBUG_TRACE_INPUT)
+    DEBUG_MESSAGE1 ("input read from %s", title);
+
+  i = (input_block *) obstack_alloc (current_input,
+				     sizeof (struct input_block));
+  i->type = INPUT_FILE;
+  i->file = (char *) obstack_copy0 (&file_names, title, strlen (title));
+  i->line = 1;
+  input_change = true;
+
+  i->u.u_f.fp = fp;
+  i->u.u_f.end = false;
+  i->u.u_f.close = close;
+  i->u.u_f.advance_line = start_of_input_line;
+  output_current_line = -1;
+
+  i->prev = isp;
+  isp = i;
+}
+
+/*---------------------------------------------------------------.
+| push_macro () pushes a builtin macro's definition on the input |
+| stack.  If next is non-NULL, this push invalidates a call to   |
+| push_string_init (), whose storage is consequently released.   |
+`---------------------------------------------------------------*/
+
+void
+push_macro (builtin_func *func)
+{
+  input_block *i;
+
+  if (next != NULL)
+    {
+      obstack_free (current_input, next);
+      next = NULL;
+    }
+
+  i = (input_block *) obstack_alloc (current_input,
+				     sizeof (struct input_block));
+  i->type = INPUT_MACRO;
+  i->file = current_file;
+  i->line = current_line;
+  input_change = true;
+
+  i->u.func = func;
+  i->prev = isp;
+  isp = i;
+}
+
+/*------------------------------------------------------------------.
+| First half of push_string ().  The pointer next points to the new |
+| input_block.							    |
+`------------------------------------------------------------------*/
+
+struct obstack *
+push_string_init (void)
+{
+  if (next != NULL)
+    {
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: recursive push_string!"));
+      abort ();
+    }
+
+  next = (input_block *) obstack_alloc (current_input,
+					sizeof (struct input_block));
+  next->type = INPUT_STRING;
+  next->file = current_file;
+  next->line = current_line;
+
+  return current_input;
+}
+
+/*------------------------------------------------------------------------.
+| Last half of push_string ().  If next is now NULL, a call to push_file  |
+| () has invalidated the previous call to push_string_init (), so we just |
+| give up.  If the new object is void, we do not push it.  The function	  |
+| push_string_finish () returns a pointer to the finished object.  This	  |
+| pointer is only for temporary use, since reading the next token might	  |
+| release the memory used for the object.				  |
+`------------------------------------------------------------------------*/
+
+const char *
+push_string_finish (void)
+{
+  const char *ret = NULL;
+
+  if (next == NULL)
+    return NULL;
+
+  if (obstack_object_size (current_input) > 0)
+    {
+      obstack_1grow (current_input, '\0');
+      next->u.u_s.string = (char *) obstack_finish (current_input);
+      next->prev = isp;
+      isp = next;
+      ret = isp->u.u_s.string;	/* for immediate use only */
+      input_change = true;
+    }
+  else
+    obstack_free (current_input, next); /* people might leave garbage on it. */
+  next = NULL;
+  return ret;
+}
+
+/*------------------------------------------------------------------.
+| The function push_wrapup () pushes a string on the wrapup stack.  |
+| When the normal input stack gets empty, the wrapup stack will     |
+| become the input stack, and push_string () and push_file () will  |
+| operate on wrapup_stack.  Push_wrapup should be done as           |
+| push_string (), but this will suffice, as long as arguments to    |
+| m4_m4wrap () are moderate in size.                                |
+`------------------------------------------------------------------*/
+
+void
+push_wrapup (const char *s)
+{
+  input_block *i;
+  i = (input_block *) obstack_alloc (wrapup_stack,
+				     sizeof (struct input_block));
+  i->prev = wsp;
+  i->type = INPUT_STRING;
+  i->file = current_file;
+  i->line = current_line;
+  i->u.u_s.string = (char *) obstack_copy0 (wrapup_stack, s, strlen (s));
+  wsp = i;
+}
+
+
+/*-------------------------------------------------------------------------.
+| The function pop_input () pops one level of input sources.  If the	   |
+| popped input_block is a file, current_file and current_line are reset to |
+| the saved values before the memory for the input_block are released.	   |
+`-------------------------------------------------------------------------*/
+
+static void
+pop_input (void)
+{
+  input_block *tmp = isp->prev;
+
+  switch (isp->type)
+    {
+    case INPUT_STRING:
+    case INPUT_MACRO:
+      break;
+
+    case INPUT_FILE:
+      if (debug_level & DEBUG_TRACE_INPUT)
+	{
+	  if (tmp)
+	    DEBUG_MESSAGE2 ("input reverted to %s, line %d",
+			    tmp->file, tmp->line);
+	  else
+	    DEBUG_MESSAGE ("input exhausted");
+	}
+
+      if (ferror (isp->u.u_f.fp))
+	{
+	  M4ERROR ((warning_status, 0, "read error"));
+	  if (isp->u.u_f.close)
+	    fclose (isp->u.u_f.fp);
+	  retcode = EXIT_FAILURE;
+	}
+      else if (isp->u.u_f.close && fclose (isp->u.u_f.fp) == EOF)
+	{
+	  M4ERROR ((warning_status, errno, "error reading file"));
+	  retcode = EXIT_FAILURE;
+	}
+      start_of_input_line = isp->u.u_f.advance_line;
+      output_current_line = -1;
+      break;
+
+    default:
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: input stack botch in pop_input ()"));
+      abort ();
+    }
+  obstack_free (current_input, isp);
+  next = NULL;			/* might be set in push_string_init () */
+
+  isp = tmp;
+  input_change = true;
+}
+
+/*------------------------------------------------------------------------.
+| To switch input over to the wrapup stack, main () calls pop_wrapup ().  |
+| Since wrapup text can install new wrapup text, pop_wrapup () returns	  |
+| false when there is no wrapup text on the stack, and true otherwise.	  |
+`------------------------------------------------------------------------*/
+
+bool
+pop_wrapup (void)
+{
+  next = NULL;
+  obstack_free (current_input, NULL);
+  free (current_input);
+
+  if (wsp == NULL)
+    {
+      /* End of the program.  Free all memory even though we are about
+	 to exit, since it makes leak detection easier.  */
+      obstack_free (&token_stack, NULL);
+      obstack_free (&file_names, NULL);
+      obstack_free (wrapup_stack, NULL);
+      free (wrapup_stack);
+      return false;
+    }
+
+  current_input = wrapup_stack;
+  wrapup_stack = (struct obstack *) xmalloc (sizeof (struct obstack));
+  obstack_init (wrapup_stack);
+
+  isp = wsp;
+  wsp = NULL;
+  input_change = true;
+
+  return true;
+}
+
+/*-------------------------------------------------------------------.
+| When a MACRO token is seen, next_token () uses init_macro_token () |
+| to retrieve the value of the function pointer.                     |
+`-------------------------------------------------------------------*/
+
+static void
+init_macro_token (token_data *td)
+{
+  if (isp->type != INPUT_MACRO)
+    {
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: bad call to init_macro_token ()"));
+      abort ();
+    }
+
+  TOKEN_DATA_TYPE (td) = TOKEN_FUNC;
+  TOKEN_DATA_FUNC (td) = isp->u.func;
+}
+
+
+/*------------------------------------------------------------------------.
+| Low level input is done a character at a time.  The function peek_input |
+| () is used to look at the next character in the input stream.  At any	  |
+| given time, it reads from the input_block on the top of the current	  |
+| input stack.								  |
+`------------------------------------------------------------------------*/
+
+static int
+peek_input (void)
+{
+  int ch;
+  input_block *block = isp;
+
+  while (1)
+    {
+      if (block == NULL)
+	return CHAR_EOF;
+
+      switch (block->type)
+	{
+	case INPUT_STRING:
+	  ch = to_uchar (block->u.u_s.string[0]);
+	  if (ch != '\0')
+	    return ch;
+	  break;
+
+	case INPUT_FILE:
+	  ch = getc (block->u.u_f.fp);
+	  if (ch != EOF)
+	    {
+	      ungetc (ch, block->u.u_f.fp);
+	      return ch;
+	    }
+	  block->u.u_f.end = true;
+	  break;
+
+	case INPUT_MACRO:
+	  return CHAR_MACRO;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: input stack botch in peek_input ()"));
+	  abort ();
+	}
+      block = block->prev;
+    }
+}
+
+/*-------------------------------------------------------------------------.
+| The function next_char () is used to read and advance the input to the   |
+| next character.  It also manages line numbers for error messages, so	   |
+| they do not get wrong, due to lookahead.  The token consisting of a	   |
+| newline alone is taken as belonging to the line it ends, and the current |
+| line number is not incremented until the next character is read.	   |
+| 99.9% of all calls will read from a string, so factor that out into a    |
+| macro for speed.                                                         |
+`-------------------------------------------------------------------------*/
+
+#define next_char() \
+  (isp && isp->type == INPUT_STRING && isp->u.u_s.string[0]	\
+   && !input_change						\
+   ? to_uchar (*isp->u.u_s.string++)				\
+   : next_char_1 ())
+
+static int
+next_char_1 (void)
+{
+  int ch;
+
+  while (1)
+    {
+      if (isp == NULL)
+	{
+	  current_file = "";
+	  current_line = 0;
+	  return CHAR_EOF;
+	}
+
+      if (input_change)
+	{
+	  current_file = isp->file;
+	  current_line = isp->line;
+	  input_change = false;
+	}
+
+      switch (isp->type)
+	{
+	case INPUT_STRING:
+	  ch = to_uchar (*isp->u.u_s.string++);
+	  if (ch != '\0')
+	    return ch;
+	  break;
+
+	case INPUT_FILE:
+	  if (start_of_input_line)
+	    {
+	      start_of_input_line = false;
+	      current_line = ++isp->line;
+	    }
+
+	  /* If stdin is a terminal, calling getc after peek_input
+	     already called it would make the user have to hit ^D
+	     twice to quit.  */
+	  ch = isp->u.u_f.end ? EOF : getc (isp->u.u_f.fp);
+	  if (ch != EOF)
+	    {
+	      if (ch == '\n')
+		start_of_input_line = true;
+	      return ch;
+	    }
+	  break;
+
+	case INPUT_MACRO:
+	  pop_input ();		/* INPUT_MACRO input sources has only one
+				   token */
+	  return CHAR_MACRO;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: input stack botch in next_char ()"));
+	  abort ();
+	}
+
+      /* End of input source --- pop one level.  */
+      pop_input ();
+    }
+}
+
+/*------------------------------------------------------------------------.
+| skip_line () simply discards all immediately following characters, upto |
+| the first newline.  It is only used from m4_dnl ().			  |
+`------------------------------------------------------------------------*/
+
+void
+skip_line (void)
+{
+  int ch;
+  const char *file = current_file;
+  int line = current_line;
+
+  while ((ch = next_char ()) != CHAR_EOF && ch != '\n')
+    ;
+  if (ch == CHAR_EOF)
+    /* current_file changed to "" if we see CHAR_EOF, use the
+       previous value we stored earlier.  */
+    M4ERROR_AT_LINE ((warning_status, 0, file, line,
+		      "Warning: end of file treated as newline"));
+  /* On the rare occasion that dnl crosses include file boundaries
+     (either the input file did not end in a newline, or changeword
+     was used), calling next_char can update current_file and
+     current_line, and that update will be undone as we return to
+     expand_macro.  This informs next_char to fix things again.  */
+  if (file != current_file || line != current_line)
+    input_change = true;
+}
+
+
+/*------------------------------------------------------------------.
+| This function is for matching a string against a prefix of the    |
+| input stream.  If the string matches the input and consume is     |
+| true, the input is discarded; otherwise any characters read are   |
+| pushed back again.  The function is used only when multicharacter |
+| quotes or comment delimiters are used.                            |
+`------------------------------------------------------------------*/
+
+static bool
+match_input (const char *s, bool consume)
+{
+  int n;			/* number of characters matched */
+  int ch;			/* input character */
+  const char *t;
+  bool result = false;
+
+  ch = peek_input ();
+  if (ch != to_uchar (*s))
+    return false;			/* fail */
+
+  if (s[1] == '\0')
+    {
+      if (consume)
+	(void) next_char ();
+      return true;			/* short match */
+    }
+
+  (void) next_char ();
+  for (n = 1, t = s++; (ch = peek_input ()) == to_uchar (*s++); )
+    {
+      (void) next_char ();
+      n++;
+      if (*s == '\0')		/* long match */
+	{
+	  if (consume)
+	    return true;
+	  result = true;
+	  break;
+	}
+    }
+
+  /* Failed or shouldn't consume, push back input.  */
+  {
+    struct obstack *h = push_string_init ();
+
+    /* `obstack_grow' may be macro evaluating its arg 1 several times. */
+    obstack_grow (h, t, n);
+  }
+  push_string_finish ();
+  return result;
+}
+
+/*--------------------------------------------------------------------.
+| The macro MATCH() is used to match a string S against the input.    |
+| The first character is handled inline, for speed.  Hopefully, this  |
+| will not hurt efficiency too much when single character quotes and  |
+| comment delimiters are used.  If CONSUME, then CH is the result of  |
+| next_char, and a successful match will discard the matched string.  |
+| Otherwise, CH is the result of peek_char, and the input stream is   |
+| effectively unchanged.                                              |
+`--------------------------------------------------------------------*/
+
+#define MATCH(ch, s, consume)                                           \
+  (to_uchar ((s)[0]) == (ch)                                            \
+   && (ch) != '\0'                                                      \
+   && ((s)[1] == '\0' || (match_input ((s) + (consume), consume))))
+
+
+/*----------------------------------------------------------.
+| Inititialise input stacks, and quote/comment characters.  |
+`----------------------------------------------------------*/
+
+void
+input_init (void)
+{
+  current_file = "";
+  current_line = 0;
+
+  current_input = (struct obstack *) xmalloc (sizeof (struct obstack));
+  obstack_init (current_input);
+  wrapup_stack = (struct obstack *) xmalloc (sizeof (struct obstack));
+  obstack_init (wrapup_stack);
+
+  obstack_init (&file_names);
+
+  /* Allocate an object in the current chunk, so that obstack_free
+     will always work even if the first token parsed spills to a new
+     chunk.  */
+  obstack_init (&token_stack);
+  obstack_alloc (&token_stack, 1);
+  token_bottom = obstack_base (&token_stack);
+
+  isp = NULL;
+  wsp = NULL;
+  next = NULL;
+
+  start_of_input_line = false;
+
+  lquote.string = xstrdup (DEF_LQUOTE);
+  lquote.length = strlen (lquote.string);
+  rquote.string = xstrdup (DEF_RQUOTE);
+  rquote.length = strlen (rquote.string);
+  bcomm.string = xstrdup (DEF_BCOMM);
+  bcomm.length = strlen (bcomm.string);
+  ecomm.string = xstrdup (DEF_ECOMM);
+  ecomm.length = strlen (ecomm.string);
+
+#ifdef ENABLE_CHANGEWORD
+  set_word_regexp (user_word_regexp);
+#endif
+}
+
+
+/*------------------------------------------------------------------.
+| Functions for setting quotes and comment delimiters.  Used by	    |
+| m4_changecom () and m4_changequote ().  Pass NULL if the argument |
+| was not present, to distinguish from an explicit empty string.    |
+`------------------------------------------------------------------*/
+
+void
+set_quotes (const char *lq, const char *rq)
+{
+  free (lquote.string);
+  free (rquote.string);
+
+  /* POSIX states that with 0 arguments, the default quotes are used.
+     POSIX XCU ERN 112 states that behavior is implementation-defined
+     if there was only one argument, or if there is an empty string in
+     either position when there are two arguments.  We allow an empty
+     left quote to disable quoting, but a non-empty left quote will
+     always create a non-empty right quote.  See the texinfo for what
+     some other implementations do.  */
+  if (!lq)
+    {
+      lq = DEF_LQUOTE;
+      rq = DEF_RQUOTE;
+    }
+  else if (!rq || (*lq && !*rq))
+    rq = DEF_RQUOTE;
+
+  lquote.string = xstrdup (lq);
+  lquote.length = strlen (lquote.string);
+  rquote.string = xstrdup (rq);
+  rquote.length = strlen (rquote.string);
+}
+
+void
+set_comment (const char *bc, const char *ec)
+{
+  free (bcomm.string);
+  free (ecomm.string);
+
+  /* POSIX requires no arguments to disable comments.  It requires
+     empty arguments to be used as-is, but this is counter to
+     traditional behavior, because a non-null begin and null end makes
+     it impossible to end a comment.  An aardvark has been filed:
+     http://www.opengroup.org/austin/mailarchives/ag-review/msg02168.html
+     This implementation assumes the aardvark will be approved.  See
+     the texinfo for what some other implementations do.  */
+  if (!bc)
+    bc = ec = "";
+  else if (!ec || (*bc && !*ec))
+    ec = DEF_ECOMM;
+
+  bcomm.string = xstrdup (bc);
+  bcomm.length = strlen (bcomm.string);
+  ecomm.string = xstrdup (ec);
+  ecomm.length = strlen (ecomm.string);
+}
+
+#ifdef ENABLE_CHANGEWORD
+
+static void
+init_pattern_buffer (struct re_pattern_buffer *buf)
+{
+  buf->translate = NULL;
+  buf->fastmap = NULL;
+  buf->buffer = NULL;
+  buf->allocated = 0;
+}
+
+void
+set_word_regexp (const char *regexp)
+{
+  int i;
+  char test[2];
+  const char *msg;
+  struct re_pattern_buffer new_word_regexp;
+
+  if (!*regexp || !strcmp (regexp, DEFAULT_WORD_REGEXP))
+    {
+      default_word_regexp = true;
+      return;
+    }
+
+  /* Dry run to see whether the new expression is compilable.  */
+  init_pattern_buffer (&new_word_regexp);
+  msg = re_compile_pattern (regexp, strlen (regexp), &new_word_regexp);
+  regfree (&new_word_regexp);
+
+  if (msg != NULL)
+    {
+      M4ERROR ((warning_status, 0,
+		"bad regular expression `%s': %s", regexp, msg));
+      return;
+    }
+
+  /* If compilation worked, retry using the word_regexp struct.
+     Can't rely on struct assigns working, so redo the compilation.  */
+  regfree (&word_regexp);
+  msg = re_compile_pattern (regexp, strlen (regexp), &word_regexp);
+  re_set_registers (&word_regexp, &regs, regs.num_regs, regs.start, regs.end);
+
+  if (msg != NULL)
+    {
+      M4ERROR ((EXIT_FAILURE, 0,
+		"INTERNAL ERROR: expression recompilation `%s': %s",
+		regexp, msg));
+    }
+
+  default_word_regexp = false;
+
+  if (word_start == NULL)
+    word_start = (char *) xmalloc (256);
+
+  word_start[0] = '\0';
+  test[1] = '\0';
+  for (i = 1; i < 256; i++)
+    {
+      test[0] = i;
+      word_start[i] = re_search (&word_regexp, test, 1, 0, 0, NULL) >= 0;
+    }
+}
+
+#endif /* ENABLE_CHANGEWORD */
+
+
+/*-------------------------------------------------------------------------.
+| Parse and return a single token from the input stream.  A token can	   |
+| either be TOKEN_EOF, if the input_stack is empty; it can be TOKEN_STRING |
+| for a quoted string; TOKEN_WORD for something that is a potential macro  |
+| name; and TOKEN_SIMPLE for any single character that is not a part of	   |
+| any of the previous types.						   |
+|									   |
+| Next_token () return the token type, and passes back a pointer to the	   |
+| token data through TD.  The token text is collected on the obstack	   |
+| token_stack, which never contains more than one token text at a time.	   |
+| The storage pointed to by the fields in TD is therefore subject to	   |
+| change the next time next_token () is called.				   |
+`-------------------------------------------------------------------------*/
+
+token_type
+next_token (token_data *td)
+{
+  int ch;
+  int quote_level;
+  token_type type;
+#ifdef ENABLE_CHANGEWORD
+  int startpos;
+  char *orig_text = NULL;
+#endif
+  const char *file;
+  int line;
+
+  obstack_free (&token_stack, token_bottom);
+
+ /* Can't consume character until after CHAR_MACRO is handled.  */
+  ch = peek_input ();
+  if (ch == CHAR_EOF)
+    {
+#ifdef DEBUG_INPUT
+      fprintf (stderr, "next_token -> EOF\n");
+#endif
+      next_char ();
+      return TOKEN_EOF;
+    }
+  if (ch == CHAR_MACRO)
+    {
+      init_macro_token (td);
+      next_char ();
+#ifdef DEBUG_INPUT
+      fprintf (stderr, "next_token -> MACDEF (%s)\n",
+	       find_builtin_by_addr (TOKEN_DATA_FUNC (td))->name);
+#endif
+      return TOKEN_MACDEF;
+    }
+
+  next_char (); /* Consume character we already peeked at.  */
+  file = current_file;
+  line = current_line;
+  if (MATCH (ch, bcomm.string, true))
+    {
+      obstack_grow (&token_stack, bcomm.string, bcomm.length);
+      while ((ch = next_char ()) != CHAR_EOF
+	     && !MATCH (ch, ecomm.string, true))
+	obstack_1grow (&token_stack, ch);
+      if (ch != CHAR_EOF)
+	obstack_grow (&token_stack, ecomm.string, ecomm.length);
+      else
+	/* current_file changed to "" if we see CHAR_EOF, use the
+	   previous value we stored earlier.  */
+	M4ERROR_AT_LINE ((EXIT_FAILURE, 0, file, line,
+			  "ERROR: end of file in comment"));
+
+      type = TOKEN_STRING;
+    }
+  else if (default_word_regexp && (isalpha (ch) || ch == '_'))
+    {
+      obstack_1grow (&token_stack, ch);
+      while ((ch = peek_input ()) != CHAR_EOF && (isalnum (ch) || ch == '_'))
+	{
+	  obstack_1grow (&token_stack, ch);
+	  (void) next_char ();
+	}
+      type = TOKEN_WORD;
+    }
+
+#ifdef ENABLE_CHANGEWORD
+
+  else if (!default_word_regexp && word_start[ch])
+    {
+      obstack_1grow (&token_stack, ch);
+      while (1)
+	{
+	  ch = peek_input ();
+	  if (ch == CHAR_EOF)
+	    break;
+	  obstack_1grow (&token_stack, ch);
+	  startpos = re_search (&word_regexp,
+				(char *) obstack_base (&token_stack),
+				obstack_object_size (&token_stack), 0, 0,
+				&regs);
+	  if (startpos != 0 ||
+	      regs.end [0] != obstack_object_size (&token_stack))
+	    {
+	      *(((char *) obstack_base (&token_stack)
+		 + obstack_object_size (&token_stack)) - 1) = '\0';
+	      break;
+	    }
+	  next_char ();
+	}
+
+      obstack_1grow (&token_stack, '\0');
+      orig_text = (char *) obstack_finish (&token_stack);
+
+      if (regs.start[1] != -1)
+	obstack_grow (&token_stack,orig_text + regs.start[1],
+		      regs.end[1] - regs.start[1]);
+      else
+	obstack_grow (&token_stack, orig_text,regs.end[0]);
+
+      type = TOKEN_WORD;
+    }
+
+#endif /* ENABLE_CHANGEWORD */
+
+  else if (!MATCH (ch, lquote.string, true))
+    {
+      switch (ch)
+	{
+	case '(':
+	  type = TOKEN_OPEN;
+	  break;
+	case ',':
+	  type = TOKEN_COMMA;
+	  break;
+	case ')':
+	  type = TOKEN_CLOSE;
+	  break;
+	default:
+	  type = TOKEN_SIMPLE;
+	  break;
+	}
+      obstack_1grow (&token_stack, ch);
+    }
+  else
+    {
+      quote_level = 1;
+      while (1)
+	{
+	  ch = next_char ();
+	  if (ch == CHAR_EOF)
+	    /* current_file changed to "" if we see CHAR_EOF, use
+	       the previous value we stored earlier.  */
+	    M4ERROR_AT_LINE ((EXIT_FAILURE, 0, file, line,
+			      "ERROR: end of file in string"));
+
+	  if (MATCH (ch, rquote.string, true))
+	    {
+	      if (--quote_level == 0)
+		break;
+	      obstack_grow (&token_stack, rquote.string, rquote.length);
+	    }
+	  else if (MATCH (ch, lquote.string, true))
+	    {
+	      quote_level++;
+	      obstack_grow (&token_stack, lquote.string, lquote.length);
+	    }
+	  else
+	    obstack_1grow (&token_stack, ch);
+	}
+      type = TOKEN_STRING;
+    }
+
+  obstack_1grow (&token_stack, '\0');
+
+  TOKEN_DATA_TYPE (td) = TOKEN_TEXT;
+  TOKEN_DATA_TEXT (td) = (char *) obstack_finish (&token_stack);
+#ifdef ENABLE_CHANGEWORD
+  if (orig_text == NULL)
+    orig_text = TOKEN_DATA_TEXT (td);
+  TOKEN_DATA_ORIG_TEXT (td) = orig_text;
+#endif
+#ifdef DEBUG_INPUT
+  fprintf (stderr, "next_token -> %s (%s)\n",
+	   token_type_string (type), TOKEN_DATA_TEXT (td));
+#endif
+  return type;
+}
+
+/*-----------------------------------------------.
+| Peek at the next token from the input stream.  |
+`-----------------------------------------------*/
+
+token_type
+peek_token (void)
+{
+  token_type result;
+  int ch = peek_input ();
+
+  if (ch == CHAR_EOF)
+    {
+      result = TOKEN_EOF;
+    }
+  else if (ch == CHAR_MACRO)
+    {
+      result = TOKEN_MACDEF;
+    }
+  else if (MATCH (ch, bcomm.string, false))
+    {
+      result = TOKEN_STRING;
+    }
+  else if ((default_word_regexp && (isalpha (ch) || ch == '_'))
+#ifdef ENABLE_CHANGEWORD
+      || (! default_word_regexp && word_start[ch])
+#endif /* ENABLE_CHANGEWORD */
+      )
+    {
+      result = TOKEN_WORD;
+    }
+  else if (MATCH (ch, lquote.string, false))
+    {
+      result = TOKEN_STRING;
+    }
+  else
+    switch (ch)
+      {
+      case '(':
+	result = TOKEN_OPEN;
+	break;
+      case ',':
+	result = TOKEN_COMMA;
+	break;
+      case ')':
+	result = TOKEN_CLOSE;
+	break;
+      default:
+	result = TOKEN_SIMPLE;
+      }
+
+#ifdef DEBUG_INPUT
+  fprintf (stderr, "peek_token -> %s\n", token_type_string (result));
+#endif /* DEBUG_INPUT */
+  return result;
+}
+
+
+#ifdef DEBUG_INPUT
+
+static const char *
+token_type_string (token_type t)
+{
+ switch (t)
+    {				/* TOKSW */
+    case TOKEN_EOF:
+      return "EOF";
+    case TOKEN_STRING:
+      return "STRING";
+    case TOKEN_WORD:
+      return "WORD";
+    case TOKEN_OPEN:
+      return "OPEN";
+    case TOKEN_COMMA:
+      return "COMMA";
+    case TOKEN_CLOSE:
+      return "CLOSE";
+    case TOKEN_SIMPLE:
+      return "SIMPLE";
+    case TOKEN_MACDEF:
+      return "MACDEF";
+    default:
+      abort ();
+    }
+ }
+
+static void
+print_token (const char *s, token_type t, token_data *td)
+{
+  fprintf (stderr, "%s: ", s);
+  switch (t)
+    {				/* TOKSW */
+    case TOKEN_OPEN:
+    case TOKEN_COMMA:
+    case TOKEN_CLOSE:
+    case TOKEN_SIMPLE:
+      fprintf (stderr, "char:");
+      break;
+
+    case TOKEN_WORD:
+      fprintf (stderr, "word:");
+      break;
+
+    case TOKEN_STRING:
+      fprintf (stderr, "string:");
+      break;
+
+    case TOKEN_MACDEF:
+      fprintf (stderr, "macro: %p\n", TOKEN_DATA_FUNC (td));
+      break;
+
+    case TOKEN_EOF:
+      fprintf (stderr, "eof\n");
+      break;
+    }
+  fprintf (stderr, "\t\"%s\"\n", TOKEN_DATA_TEXT (td));
+}
+
+static void M4_GNUC_UNUSED
+lex_debug (void)
+{
+  token_type t;
+  token_data td;
+
+  while ((t = next_token (&td)) != TOKEN_EOF)
+    print_token ("lex", t, &td);
+}
+#endif
diff --git a/src/bin/m4/src/m4.c b/src/bin/m4/src/m4.c
new file mode 100644
index 0000000000..98b2582cf8
--- /dev/null
+++ b/src/bin/m4/src/m4.c
@@ -0,0 +1,581 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+#include "m4.h"
+
+#include <getopt.h>
+#include <limits.h>
+#include <signal.h>
+
+static void usage (int);
+
+/* Enable sync output for /lib/cpp (-s).  */
+int sync_output = 0;
+
+/* Debug (-d[flags]).  */
+int debug_level = 0;
+
+/* Hash table size (should be a prime) (-Hsize).  */
+size_t hash_table_size = HASHMAX;
+
+/* Disable GNU extensions (-G).  */
+int no_gnu_extensions = 0;
+
+/* Prefix all builtin functions by `m4_'.  */
+int prefix_all_builtins = 0;
+
+/* Max length of arguments in trace output (-lsize).  */
+int max_debug_argument_length = 0;
+
+/* Suppress warnings about missing arguments.  */
+int suppress_warnings = 0;
+
+/* If not zero, then value of exit status for warning diagnostics.  */
+int warning_status = 0;
+
+/* Artificial limit for expansion_level in macro.c.  */
+int nesting_limit = 1024;
+
+#ifdef ENABLE_CHANGEWORD
+/* User provided regexp for describing m4 words.  */
+const char *user_word_regexp = "";
+#endif
+
+/* The name this program was run with. */
+const char *program_name;
+
+struct macro_definition
+{
+  struct macro_definition *next;
+  int code;			/* D, U, s, t, or '\1' */
+  const char *arg;
+};
+typedef struct macro_definition macro_definition;
+
+/* Error handling functions.  */
+
+/*-----------------------.
+| Wrapper around error.  |
+`-----------------------*/
+
+void
+m4_error (int status, int errnum, const char *format, ...)
+{
+  va_list args;
+  va_start (args, format);
+  verror_at_line (status, errnum, current_line ? current_file : NULL,
+		  current_line, format, args);
+}
+
+/*-------------------------------.
+| Wrapper around error_at_line.  |
+`-------------------------------*/
+
+void
+m4_error_at_line (int status, int errnum, const char *file, int line,
+		  const char *format, ...)
+{
+  va_list args;
+  va_start (args, format);
+  verror_at_line (status, errnum, line ? file : NULL, line, format, args);
+}
+
+#ifdef USE_STACKOVF
+
+/*---------------------------------------.
+| Tell user stack overflowed and abort.	 |
+`---------------------------------------*/
+
+static void
+stackovf_handler (void)
+{
+  M4ERROR ((EXIT_FAILURE, 0,
+	    "ERROR: stack overflow.  (Infinite define recursion?)"));
+}
+
+#endif /* USE_STACKOV */
+
+
+/*---------------------------------------------.
+| Print a usage message and exit with STATUS.  |
+`---------------------------------------------*/
+
+static void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    fprintf (stderr, "Try `%s --help' for more information.\n", program_name);
+  else
+    {
+      printf ("Usage: %s [OPTION]... [FILE]...\n", program_name);
+      fputs ("\
+Process macros in FILEs.  If no FILE or if FILE is `-', standard input\n\
+is read.\n\
+", stdout);
+      fputs ("\
+\n\
+Mandatory or optional arguments to long options are mandatory or optional\n\
+for short options too.\n\
+\n\
+Operation modes:\n\
+      --help                   display this help and exit\n\
+      --version                output version information and exit\n\
+  -E, --fatal-warnings         stop execution after first warning\n\
+  -i, --interactive            unbuffer output, ignore interrupts\n\
+  -P, --prefix-builtins        force a `m4_' prefix to all builtins\n\
+  -Q, --quiet, --silent        suppress some warnings for builtins\n\
+", stdout);
+#ifdef ENABLE_CHANGEWORD
+      fputs ("\
+  -W, --word-regexp=REGEXP     use REGEXP for macro name syntax\n\
+", stdout);
+#endif
+      fputs ("\
+\n\
+Preprocessor features:\n\
+  -D, --define=NAME[=VALUE]    define NAME as having VALUE, or empty\n\
+  -I, --include=DIRECTORY      append DIRECTORY to include path\n\
+  -s, --synclines              generate `#line NUM \"FILE\"' lines\n\
+  -U, --undefine=NAME          undefine NAME\n\
+", stdout);
+      fputs ("\
+\n\
+Limits control:\n\
+  -G, --traditional            suppress all GNU extensions\n\
+  -H, --hashsize=PRIME         set symbol lookup hash table size [509]\n\
+  -L, --nesting-limit=NUMBER   change artificial nesting limit [1024]\n\
+", stdout);
+      fputs ("\
+\n\
+Frozen state files:\n\
+  -F, --freeze-state=FILE      produce a frozen state on FILE at end\n\
+  -R, --reload-state=FILE      reload a frozen state from FILE at start\n\
+", stdout);
+      fputs ("\
+\n\
+Debugging:\n\
+  -d, --debug[=FLAGS]          set debug level (no FLAGS implies `aeq')\n\
+      --debugfile=FILE         redirect debug and trace output\n\
+  -l, --arglength=NUM          restrict macro tracing size\n\
+  -t, --trace=NAME             trace NAME when it is defined\n\
+", stdout);
+      fputs ("\
+\n\
+FLAGS is any of:\n\
+  a   show actual arguments\n\
+  c   show before collect, after collect and after call\n\
+  e   show expansion\n\
+  f   say current input file name\n\
+  i   show changes in input files\n\
+  l   say current input line number\n\
+  p   show results of path searches\n\
+  q   quote values as necessary, with a or e flag\n\
+  t   trace for all macro calls, not only traceon'ed\n\
+  x   add a unique macro call id, useful with c flag\n\
+  V   shorthand for all of the above flags\n\
+", stdout);
+      fputs ("\
+\n\
+If defined, the environment variable `M4PATH' is a colon-separated list\n\
+of directories included after any specified by `-I'.\n\
+", stdout);
+      fputs ("\
+\n\
+Exit status is 0 for success, 1 for failure, 63 for frozen file version\n\
+mismatch, or whatever value was passed to the m4exit macro.\n\
+", stdout);
+      printf ("\nReport bugs to <%s>.\n", PACKAGE_BUGREPORT);
+    }
+  exit (status);
+}
+
+/*--------------------------------------.
+| Decode options and launch execution.  |
+`--------------------------------------*/
+
+/* For long options that have no equivalent short option, use a
+   non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
+enum
+{
+  DEBUGFILE_OPTION = CHAR_MAX + 1,	/* no short opt */
+  DIVERSIONS_OPTION,			/* not quite -N, because of message */
+
+  HELP_OPTION,				/* no short opt */
+  VERSION_OPTION			/* no short opt */
+};
+
+static const struct option long_options[] =
+{
+  {"arglength", required_argument, NULL, 'l'},
+  {"debug", optional_argument, NULL, 'd'},
+  {"define", required_argument, NULL, 'D'},
+  {"error-output", required_argument, NULL, 'o'}, /* FIXME: deprecate in 2.0 */
+  {"fatal-warnings", no_argument, NULL, 'E'},
+  {"freeze-state", required_argument, NULL, 'F'},
+  {"hashsize", required_argument, NULL, 'H'},
+  {"include", required_argument, NULL, 'I'},
+  {"interactive", no_argument, NULL, 'i'},
+  {"nesting-limit", required_argument, NULL, 'L'},
+  {"prefix-builtins", no_argument, NULL, 'P'},
+  {"quiet", no_argument, NULL, 'Q'},
+  {"reload-state", required_argument, NULL, 'R'},
+  {"silent", no_argument, NULL, 'Q'},
+  {"synclines", no_argument, NULL, 's'},
+  {"trace", required_argument, NULL, 't'},
+  {"traditional", no_argument, NULL, 'G'},
+  {"undefine", required_argument, NULL, 'U'},
+  {"word-regexp", required_argument, NULL, 'W'},
+
+  {"debugfile", required_argument, NULL, DEBUGFILE_OPTION},
+  {"diversions", required_argument, NULL, DIVERSIONS_OPTION},
+
+  {"help", no_argument, NULL, HELP_OPTION},
+  {"version", no_argument, NULL, VERSION_OPTION},
+
+  { NULL, 0, NULL, 0 },
+};
+
+/* Global catchall for any errors that should affect final error status, but
+   where we try to continue execution in the meantime.  */
+int retcode;
+
+/* Process a command line file NAME, and return true only if it was
+   stdin.  */
+static bool
+process_file (const char *name)
+{
+  bool result = false;
+  if (strcmp (name, "-") == 0)
+    {
+      /* If stdin is a terminal, we want to allow 'm4 - file -'
+	 to read input from stdin twice, like GNU cat.  Besides,
+	 there is no point closing stdin before wrapped text, to
+	 minimize bugs in syscmd called from wrapped text.  */
+      push_file (stdin, "stdin", false);
+      result = true;
+    }
+  else
+    {
+      char *full_name;
+      FILE *fp = m4_path_search (name, &full_name);
+      if (fp == NULL)
+	{
+	  error (0, errno, "%s", name);
+	  /* Set the status to EXIT_FAILURE, even though we
+	     continue to process files after a missing file.  */
+	  retcode = EXIT_FAILURE;
+	  return false;
+	}
+      push_file (fp, full_name, true);
+      free (full_name);
+    }
+  expand_input ();
+  return result;
+}
+
+/* POSIX requires only -D, -U, and -s; and says that the first two
+   must be recognized when interspersed with file names.  Traditional
+   behavior also handles -s between files.  Starting OPTSTRING with
+   '-' forces getopt_long to hand back file names as arguments to opt
+   '\1', rather than reordering the command line.  */
+#ifdef ENABLE_CHANGEWORD
+#define OPTSTRING "-B:D:EF:GH:I:L:N:PQR:S:T:U:W:d::eil:o:st:"
+#else
+#define OPTSTRING "-B:D:EF:GH:I:L:N:PQR:S:T:U:d::eil:o:st:"
+#endif
+
+int
+main (int argc, char *const *argv, char *const *envp)
+{
+  macro_definition *head;	/* head of deferred argument list */
+  macro_definition *tail;
+  macro_definition *defn;
+  int optchar;			/* option character */
+
+  macro_definition *defines;
+  bool read_stdin = false;
+  bool interactive = false;
+  bool seen_file = false;
+  const char *debugfile = NULL;
+  const char *frozen_file_to_read = NULL;
+  const char *frozen_file_to_write = NULL;
+
+  program_name = argv[0];
+  retcode = EXIT_SUCCESS;
+  atexit (close_stdout);
+
+  include_init ();
+  debug_init ();
+#ifdef USE_STACKOVF
+  setup_stackovf_trap (argv, envp, stackovf_handler);
+#endif
+
+  /* First, we decode the arguments, to size up tables and stuff.  */
+
+  head = tail = NULL;
+
+  while ((optchar = getopt_long (argc, (char **) argv, OPTSTRING,
+				 long_options, NULL)) != -1)
+    switch (optchar)
+      {
+      default:
+	usage (EXIT_FAILURE);
+
+      case 'B':
+      case 'S':
+      case 'T':
+	/* Compatibility junk: options that other implementations
+	   support, but which we ignore as no-ops and don't list in
+	   --help.  */
+	error (0, 0, "Warning: `m4 -%c' may be removed in a future release",
+	       optchar);
+	break;
+
+      case 'N':
+      case DIVERSIONS_OPTION:
+	/* -N became an obsolete no-op in 1.4.x.  */
+	error (0, 0, "Warning: `m4 %s' is deprecated",
+	       optchar == 'N' ? "-N" : "--diversions");
+
+      case 'D':
+      case 'U':
+      case 's':
+      case 't':
+      case '\1':
+	/* Arguments that cannot be handled until later are accumulated.  */
+
+	defn = (macro_definition *) xmalloc (sizeof (macro_definition));
+	defn->code = optchar;
+	defn->arg = optarg;
+	defn->next = NULL;
+
+	if (head == NULL)
+	  head = defn;
+	else
+	  tail->next = defn;
+	tail = defn;
+
+	break;
+
+      case 'E':
+	warning_status = EXIT_FAILURE;
+	break;
+
+      case 'F':
+	frozen_file_to_write = optarg;
+	break;
+
+      case 'G':
+	no_gnu_extensions = 1;
+	break;
+
+      case 'H':
+	hash_table_size = atol (optarg);
+	if (hash_table_size == 0)
+	  hash_table_size = HASHMAX;
+	break;
+
+      case 'I':
+	add_include_directory (optarg);
+	break;
+
+      case 'L':
+	nesting_limit = atoi (optarg);
+	break;
+
+      case 'P':
+	prefix_all_builtins = 1;
+	break;
+
+      case 'Q':
+	suppress_warnings = 1;
+	break;
+
+      case 'R':
+	frozen_file_to_read = optarg;
+	break;
+
+#ifdef ENABLE_CHANGEWORD
+      case 'W':
+	user_word_regexp = optarg;
+	break;
+#endif
+
+      case 'd':
+	debug_level = debug_decode (optarg);
+	if (debug_level < 0)
+	  {
+	    error (0, 0, "bad debug flags: `%s'", optarg);
+	    debug_level = 0;
+	  }
+	break;
+
+      case 'e':
+	error (0, 0, "Warning: `m4 -e' is deprecated, use `-i' instead");
+	/* fall through */
+      case 'i':
+	interactive = true;
+	break;
+
+      case 'l':
+	max_debug_argument_length = atoi (optarg);
+	if (max_debug_argument_length <= 0)
+	  max_debug_argument_length = 0;
+	break;
+
+      case 'o':
+	/* -o/--error-output are deprecated synonyms of --debugfile,
+	   but don't issue a deprecation warning until autoconf 2.61
+	   or later is more widely established, as such a warning
+	   would interfere with all earlier versions of autoconf.  */
+      case DEBUGFILE_OPTION:
+	/* Don't call debug_set_output here, as it has side effects.  */
+	debugfile = optarg;
+	break;
+
+      case VERSION_OPTION:
+	printf ("%s\n", PACKAGE_STRING);
+	fputs ("\
+Copyright (C) 2006 Free Software Foundation, Inc.\n\
+This is free software; see the source for copying conditions.  There is NO\n\
+warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
+\n\
+Written by Rene' Seindal.\n\
+", stdout);
+	exit (EXIT_SUCCESS);
+	break;
+
+      case HELP_OPTION:
+	usage (EXIT_SUCCESS);
+	break;
+      }
+
+  defines = head;
+
+  /* Do the basic initializations.  */
+  if (debugfile && !debug_set_output (debugfile))
+    M4ERROR ((0, errno, "cannot set debug file `%s'", debugfile));
+
+  input_init ();
+  output_init ();
+  symtab_init ();
+  include_env_init ();
+
+  if (frozen_file_to_read)
+    reload_frozen_state (frozen_file_to_read);
+  else
+    builtin_init ();
+
+  /* Interactive mode means unbuffered output, and interrupts ignored.  */
+
+  if (interactive)
+    {
+      signal (SIGINT, SIG_IGN);
+      setbuf (stdout, (char *) NULL);
+    }
+
+  /* Handle deferred command line macro definitions.  Must come after
+     initialization of the symbol table.  */
+
+  while (defines != NULL)
+    {
+      macro_definition *next;
+      symbol *sym;
+
+      switch (defines->code)
+	{
+	case 'D':
+	  {
+	    /* defines->arg is read-only, so we need a copy.  */
+	    char *macro_name = xstrdup (defines->arg);
+	    char *macro_value = strchr (macro_name, '=');
+	    if (macro_value)
+	      *macro_value++ = '\0';
+	    define_user_macro (macro_name, macro_value, SYMBOL_INSERT);
+	    free (macro_name);
+	  }
+	  break;
+
+	case 'U':
+	  lookup_symbol (defines->arg, SYMBOL_DELETE);
+	  break;
+
+	case 't':
+	  sym = lookup_symbol (defines->arg, SYMBOL_INSERT);
+	  SYMBOL_TRACED (sym) = true;
+	  break;
+
+	case 's':
+	  sync_output = 1;
+	  break;
+
+	case '\1':
+	  seen_file = true;
+	  if (process_file (defines->arg))
+	    read_stdin = true;
+	  break;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: bad code in deferred arguments"));
+	  abort ();
+	}
+
+      next = defines->next;
+      free (defines);
+      defines = next;
+    }
+
+  /* Handle remaining input files.  Each file is pushed on the input,
+     and the input read.  Wrapup text is handled separately later.  */
+
+  if (optind == argc && !seen_file)
+    read_stdin = process_file ("-");
+  else
+    for (; optind < argc; optind++)
+      if (process_file (defines->arg))
+	read_stdin = true;
+
+  /* Now handle wrapup text.  */
+
+  while (pop_wrapup ())
+    expand_input ();
+
+  /* Change debug stream back to stderr, to force flushing the debug
+     stream and detect any errors it might have encountered.  Close
+     stdin if we read from it, to detect any errors.  */
+  debug_set_output (NULL);
+  if (read_stdin && fclose (stdin) == EOF)
+    {
+      M4ERROR ((warning_status, errno, "error reading file"));
+      retcode = EXIT_FAILURE;
+    }
+
+  if (frozen_file_to_write)
+    produce_frozen_state (frozen_file_to_write);
+  else
+    {
+      make_diversion (0);
+      undivert_all ();
+    }
+  output_exit ();
+  exit (retcode);
+}
diff --git a/src/bin/m4/src/m4.h b/src/bin/m4/src/m4.h
new file mode 100644
index 0000000000..809da2ec15
--- /dev/null
+++ b/src/bin/m4/src/m4.h
@@ -0,0 +1,458 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* We use <config.h> instead of "config.h" so that a compilation
+   using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
+   (which it would do because it found this file in $srcdir).  */
+
+#include <config.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "binary-io.h"
+#include "clean-temp.h"
+#include "cloexec.h"
+#include "close-stream.h"
+#include "closeout.h"
+#include "error.h"
+#include "exit.h"
+#include "exitfail.h"
+#include "obstack.h"
+#include "stdio--.h"
+#include "stdlib--.h"
+#include "unistd--.h"
+#include "verror.h"
+#include "xalloc.h"
+#include "xvasprintf.h"
+
+/* Canonicalize UNIX recognition macros.  */
+#if defined unix || defined __unix || defined __unix__ \
+  || defined _POSIX_VERSION || defined _POSIX2_VERSION \
+  || defined __NetBSD__ || defined __OpenBSD__ \
+  || defined __APPLE__ || defined __APPLE_CC__
+# define UNIX 1
+#endif
+
+/* Canonicalize Windows recognition macros.  */
+#if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
+# define W32_NATIVE 1
+#endif
+
+/* Canonicalize OS/2 recognition macro.  */
+#ifdef __EMX__
+# define OS2 1
+#endif
+
+/* Used for version mismatch, when -R detects a frozen file it can't parse.  */
+#define EXIT_MISMATCH 63
+
+/* Various declarations.  */
+
+struct string
+  {
+    char *string;		/* characters of the string */
+    size_t length;		/* length of the string */
+  };
+typedef struct string STRING;
+
+/* Memory allocation.  */
+#define obstack_chunk_alloc	xmalloc
+#define obstack_chunk_free	free
+
+/* Those must come first.  */
+typedef struct token_data token_data;
+typedef void builtin_func (struct obstack *, int, token_data **);
+
+/* Take advantage of GNU C compiler source level optimization hints,
+   using portable macros.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 6)
+#  define M4_GNUC_ATTRIBUTE(args)	__attribute__(args)
+#else
+#  define M4_GNUC_ATTRIBUTE(args)
+#endif  /* __GNUC__ */
+
+#define M4_GNUC_UNUSED		M4_GNUC_ATTRIBUTE((__unused__))
+#define M4_GNUC_PRINTF(fmt, arg)			\
+  M4_GNUC_ATTRIBUTE((__format__ (__printf__, fmt, arg)))
+
+/* File: m4.c  --- global definitions.  */
+
+/* Option flags.  */
+extern int sync_output;			/* -s */
+extern int debug_level;			/* -d */
+extern size_t hash_table_size;		/* -H */
+extern int no_gnu_extensions;		/* -G */
+extern int prefix_all_builtins;		/* -P */
+extern int max_debug_argument_length;	/* -l */
+extern int suppress_warnings;		/* -Q */
+extern int warning_status;		/* -E */
+extern int nesting_limit;		/* -L */
+#ifdef ENABLE_CHANGEWORD
+extern const char *user_word_regexp;	/* -W */
+#endif
+
+/* Error handling.  */
+extern int retcode;
+extern const char *program_name;
+
+void m4_error (int, int, const char *, ...) M4_GNUC_PRINTF(3, 4);
+void m4_error_at_line (int, int, const char *, int,
+                       const char *, ...) M4_GNUC_PRINTF(5, 6);
+
+#define M4ERROR(Arglist) (m4_error Arglist)
+#define M4ERROR_AT_LINE(Arglist) (m4_error_at_line Arglist)
+
+#ifdef USE_STACKOVF
+void setup_stackovf_trap (char *const *, char *const *,
+                          void (*handler) (void));
+#endif
+
+/* File: debug.c  --- debugging and tracing function.  */
+
+extern FILE *debug;
+
+/* The value of debug_level is a bitmask of the following.  */
+
+/* a: show arglist in trace output */
+#define DEBUG_TRACE_ARGS 1
+/* e: show expansion in trace output */
+#define DEBUG_TRACE_EXPANSION 2
+/* q: quote args and expansion in trace output */
+#define DEBUG_TRACE_QUOTE 4
+/* t: trace all macros -- overrides trace{on,off} */
+#define DEBUG_TRACE_ALL 8
+/* l: add line numbers to trace output */
+#define DEBUG_TRACE_LINE 16
+/* f: add file name to trace output */
+#define DEBUG_TRACE_FILE 32
+/* p: trace path search of include files */
+#define DEBUG_TRACE_PATH 64
+/* c: show macro call before args collection */
+#define DEBUG_TRACE_CALL 128
+/* i: trace changes of input files */
+#define DEBUG_TRACE_INPUT 256
+/* x: add call id to trace output */
+#define DEBUG_TRACE_CALLID 512
+
+/* V: very verbose --  print everything */
+#define DEBUG_TRACE_VERBOSE 1023
+/* default flags -- equiv: aeq */
+#define DEBUG_TRACE_DEFAULT 7
+
+#define DEBUG_PRINT1(Fmt, Arg1) \
+  do								\
+    {								\
+      if (debug != NULL)					\
+	fprintf (debug, Fmt, Arg1);				\
+    }								\
+  while (0)
+
+#define DEBUG_PRINT3(Fmt, Arg1, Arg2, Arg3) \
+  do								\
+    {								\
+      if (debug != NULL)					\
+	fprintf (debug, Fmt, Arg1, Arg2, Arg3);			\
+    }								\
+  while (0)
+
+#define DEBUG_MESSAGE(Fmt) \
+  do								\
+    {								\
+      if (debug != NULL)					\
+	{							\
+	  debug_message_prefix ();				\
+	  fprintf (debug, Fmt);					\
+	  putc ('\n', debug);					\
+	}							\
+    }								\
+  while (0)
+
+#define DEBUG_MESSAGE1(Fmt, Arg1) \
+  do								\
+    {								\
+      if (debug != NULL)					\
+	{							\
+	  debug_message_prefix ();				\
+	  fprintf (debug, Fmt, Arg1);				\
+	  putc ('\n', debug);					\
+	}							\
+    }								\
+  while (0)
+
+#define DEBUG_MESSAGE2(Fmt, Arg1, Arg2) \
+  do								\
+    {								\
+      if (debug != NULL)					\
+	{							\
+	  debug_message_prefix ();				\
+	  fprintf (debug, Fmt, Arg1, Arg2);			\
+	  putc ('\n', debug);					\
+	}							\
+    }								\
+  while (0)
+
+void debug_init (void);
+int debug_decode (const char *);
+void debug_flush_files (void);
+bool debug_set_output (const char *);
+void debug_message_prefix (void);
+
+void trace_prepre (const char *, int);
+void trace_pre (const char *, int, int, token_data **);
+void trace_post (const char *, int, int, token_data **, const char *);
+
+/* File: input.c  --- lexical definitions.  */
+
+/* Various different token types.  */
+enum token_type
+{
+  TOKEN_EOF,			/* end of file */
+  TOKEN_STRING,			/* a quoted string or comment */
+  TOKEN_WORD,			/* an identifier */
+  TOKEN_OPEN,			/* ( */
+  TOKEN_COMMA,			/* , */
+  TOKEN_CLOSE,			/* ) */
+  TOKEN_SIMPLE,			/* any other single character */
+  TOKEN_MACDEF			/* a macro's definition (see "defn") */
+};
+
+/* The data for a token, a macro argument, and a macro definition.  */
+enum token_data_type
+{
+  TOKEN_VOID,
+  TOKEN_TEXT,
+  TOKEN_FUNC
+};
+
+struct token_data
+{
+  enum token_data_type type;
+  union
+    {
+      struct
+	{
+	  char *text;
+#ifdef ENABLE_CHANGEWORD
+	  char *original_text;
+#endif
+	}
+      u_t;
+      builtin_func *func;
+    }
+  u;
+};
+
+#define TOKEN_DATA_TYPE(Td)		((Td)->type)
+#define TOKEN_DATA_TEXT(Td)		((Td)->u.u_t.text)
+#ifdef ENABLE_CHANGEWORD
+# define TOKEN_DATA_ORIG_TEXT(Td)	((Td)->u.u_t.original_text)
+#endif
+#define TOKEN_DATA_FUNC(Td)		((Td)->u.func)
+
+typedef enum token_type token_type;
+typedef enum token_data_type token_data_type;
+
+void input_init (void);
+token_type peek_token (void);
+token_type next_token (token_data *);
+void skip_line (void);
+
+/* push back input */
+void push_file (FILE *, const char *, bool);
+void push_macro (builtin_func *);
+struct obstack *push_string_init (void);
+const char *push_string_finish (void);
+void push_wrapup (const char *);
+bool pop_wrapup (void);
+
+/* current input file, and line */
+extern const char *current_file;
+extern int current_line;
+
+/* left and right quote, begin and end comment */
+extern STRING bcomm, ecomm;
+extern STRING lquote, rquote;
+
+#define DEF_LQUOTE "`"
+#define DEF_RQUOTE "\'"
+#define DEF_BCOMM "#"
+#define DEF_ECOMM "\n"
+
+void set_quotes (const char *, const char *);
+void set_comment (const char *, const char *);
+#ifdef ENABLE_CHANGEWORD
+void set_word_regexp (const char *);
+#endif
+
+/* File: output.c --- output functions.  */
+extern int current_diversion;
+extern int output_current_line;
+
+void output_init (void);
+void output_exit (void);
+void shipout_text (struct obstack *, const char *, int);
+void make_diversion (int);
+void insert_diversion (int);
+void insert_file (FILE *);
+void freeze_diversions (FILE *);
+
+/* File symtab.c  --- symbol table definitions.  */
+
+/* Operation modes for lookup_symbol ().  */
+enum symbol_lookup
+{
+  SYMBOL_LOOKUP,
+  SYMBOL_INSERT,
+  SYMBOL_DELETE,
+  SYMBOL_PUSHDEF,
+  SYMBOL_POPDEF
+};
+
+/* Symbol table entry.  */
+struct symbol
+{
+  struct symbol *next;
+  bool traced : 1;
+  bool shadowed : 1;
+  bool macro_args : 1;
+  bool blind_no_args : 1;
+  bool deleted : 1;
+  int pending_expansions;
+
+  char *name;
+  token_data data;
+};
+
+#define SYMBOL_NEXT(S)		((S)->next)
+#define SYMBOL_TRACED(S)	((S)->traced)
+#define SYMBOL_SHADOWED(S)	((S)->shadowed)
+#define SYMBOL_MACRO_ARGS(S)	((S)->macro_args)
+#define SYMBOL_BLIND_NO_ARGS(S)	((S)->blind_no_args)
+#define SYMBOL_DELETED(S)	((S)->deleted)
+#define SYMBOL_PENDING_EXPANSIONS(S) ((S)->pending_expansions)
+#define SYMBOL_NAME(S)		((S)->name)
+#define SYMBOL_TYPE(S)		(TOKEN_DATA_TYPE (&(S)->data))
+#define SYMBOL_TEXT(S)		(TOKEN_DATA_TEXT (&(S)->data))
+#define SYMBOL_FUNC(S)		(TOKEN_DATA_FUNC (&(S)->data))
+
+typedef enum symbol_lookup symbol_lookup;
+typedef struct symbol symbol;
+typedef void hack_symbol (symbol *, void *);
+
+#define HASHMAX 509		/* default, overridden by -Hsize */
+
+extern symbol **symtab;
+
+void free_symbol (symbol *sym);
+void symtab_init (void);
+symbol *lookup_symbol (const char *, symbol_lookup);
+void hack_all_symbols (hack_symbol *, void *);
+
+/* File: macro.c  --- macro expansion.  */
+
+void expand_input (void);
+void call_macro (symbol *, int, token_data **, struct obstack *);
+
+/* File: builtin.c  --- builtins.  */
+
+struct builtin
+{
+  const char *name;
+  bool gnu_extension : 1;
+  bool groks_macro_args : 1;
+  bool blind_if_no_args : 1;
+  builtin_func *func;
+};
+
+struct predefined
+{
+  const char *unix_name;
+  const char *gnu_name;
+  const char *func;
+};
+
+typedef struct builtin builtin;
+typedef struct predefined predefined;
+
+void builtin_init (void);
+void define_builtin (const char *, const builtin *, symbol_lookup);
+void define_user_macro (const char *, const char *, symbol_lookup);
+void undivert_all (void);
+void expand_user_macro (struct obstack *, symbol *, int, token_data **);
+void m4_placeholder (struct obstack *, int, token_data **);
+
+const builtin *find_builtin_by_addr (builtin_func *);
+const builtin *find_builtin_by_name (const char *);
+
+/* File: path.c  --- path search for include files.  */
+
+void include_init (void);
+void include_env_init (void);
+void add_include_directory (const char *);
+FILE *m4_path_search (const char *, char **);
+
+/* File: eval.c  --- expression evaluation.  */
+
+/* eval_t and unsigned_eval_t should be at least 32 bits.  */
+typedef int eval_t;
+typedef unsigned int unsigned_eval_t;
+
+bool evaluate (const char *, eval_t *);
+
+/* File: format.c  --- printf like formatting.  */
+
+void format (struct obstack *, int, token_data **);
+
+/* File: freeze.c --- frozen state files.  */
+
+void produce_frozen_state (const char *);
+void reload_frozen_state (const char *);
+
+/* Debugging the memory allocator.  */
+
+#ifdef WITH_DMALLOC
+# define DMALLOC_FUNC_CHECK
+# include <dmalloc.h>
+#endif
+
+/* Other debug stuff.  */
+
+#ifdef DEBUG
+# define DEBUG_INCL   1
+# define DEBUG_INPUT  1
+# define DEBUG_MACRO  1
+# define DEBUG_OUTPUT 1
+# define DEBUG_STKOVF 1
+# define DEBUG_SYM    1
+#endif
+
+/* Convert a possibly-signed character to an unsigned character.  This is
+   a bit safer than casting to unsigned char, since it catches some type
+   errors that the cast doesn't.  */
+#if HAVE_INLINE
+static inline unsigned char to_uchar (char ch) { return ch; }
+#else
+# define to_uchar(C) ((unsigned char) (C))
+#endif
diff --git a/src/bin/m4/src/m4.rdef b/src/bin/m4/src/m4.rdef
new file mode 100644
index 0000000000..0c2ad9a581
--- /dev/null
+++ b/src/bin/m4/src/m4.rdef
@@ -0,0 +1,11 @@
+resource app_version
+{
+	major = 1,
+	middle = 4,
+	minor = 8,
+	variety = B_APPV_FINAL,
+	internal = 0,
+	short_info = "m4", 
+	long_info  = "m4 ©2006 The Free Software Foundation"
+};
+
diff --git a/src/bin/m4/src/macro.c b/src/bin/m4/src/macro.c
new file mode 100644
index 0000000000..a017ece231
--- /dev/null
+++ b/src/bin/m4/src/macro.c
@@ -0,0 +1,385 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2006 Free Software
+   Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* This file contains the functions, that performs the basic argument
+   parsing and macro expansion.  */
+
+#include "m4.h"
+
+static void expand_macro (symbol *);
+static void expand_token (struct obstack *, token_type, token_data *);
+
+/* Current recursion level in expand_macro ().  */
+int expansion_level = 0;
+
+/* The number of the current call of expand_macro ().  */
+static int macro_call_id = 0;
+
+/* The shared stack of collected arguments for macro calls; as each
+   argument is collected, it is finished and its location stored in
+   argv_stack.  Normally, this stack can be used simultaneously by
+   multiple macro calls; the exception is when an outer macro has
+   generated some text, then calls a nested macro, in which case the
+   nested macro must use a local stack to leave the unfinished text
+   alone.  Too bad obstack.h does not provide an easy way to reopen a
+   finished object for further growth, but in practice this does not
+   hurt us too much.  */
+static struct obstack argc_stack;
+
+/* The shared stack of pointers to collected arguments for macro
+   calls.  This object is never finished; we exploit the fact that
+   obstack_blank is documented to take a negative size to reduce the
+   size again.  */
+static struct obstack argv_stack;
+
+/*----------------------------------------------------------------------.
+| This function read all input, and expands each token, one at a time.  |
+`----------------------------------------------------------------------*/
+
+void
+expand_input (void)
+{
+  token_type t;
+  token_data td;
+
+  obstack_init (&argc_stack);
+  obstack_init (&argv_stack);
+
+  while ((t = next_token (&td)) != TOKEN_EOF)
+    expand_token ((struct obstack *) NULL, t, &td);
+
+  obstack_free (&argc_stack, NULL);
+  obstack_free (&argv_stack, NULL);
+}
+
+
+/*------------------------------------------------------------------------.
+| Expand one token, according to its type.  Potential macro names	  |
+| (TOKEN_WORD) are looked up in the symbol table, to see if they have a	  |
+| macro definition.  If they have, they are expanded as macros, otherwise |
+| the text are just copied to the output.				  |
+`------------------------------------------------------------------------*/
+
+static void
+expand_token (struct obstack *obs, token_type t, token_data *td)
+{
+  symbol *sym;
+
+  switch (t)
+    {				/* TOKSW */
+    case TOKEN_EOF:
+    case TOKEN_MACDEF:
+      break;
+
+    case TOKEN_OPEN:
+    case TOKEN_COMMA:
+    case TOKEN_CLOSE:
+    case TOKEN_SIMPLE:
+    case TOKEN_STRING:
+      shipout_text (obs, TOKEN_DATA_TEXT (td), strlen (TOKEN_DATA_TEXT (td)));
+      break;
+
+    case TOKEN_WORD:
+      sym = lookup_symbol (TOKEN_DATA_TEXT (td), SYMBOL_LOOKUP);
+      if (sym == NULL || SYMBOL_TYPE (sym) == TOKEN_VOID
+	  || (SYMBOL_TYPE (sym) == TOKEN_FUNC
+	      && SYMBOL_BLIND_NO_ARGS (sym)
+	      && peek_token () != TOKEN_OPEN))
+	{
+#ifdef ENABLE_CHANGEWORD
+	  shipout_text (obs, TOKEN_DATA_ORIG_TEXT (td),
+			strlen (TOKEN_DATA_ORIG_TEXT (td)));
+#else
+	  shipout_text (obs, TOKEN_DATA_TEXT (td),
+			strlen (TOKEN_DATA_TEXT (td)));
+#endif
+	}
+      else
+	expand_macro (sym);
+      break;
+
+    default:
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: bad token type in expand_token ()"));
+      abort ();
+    }
+}
+
+
+/*-------------------------------------------------------------------------.
+| This function parses one argument to a macro call.  It expects the first |
+| left parenthesis, or the separating comma to have been read by the	   |
+| caller.  It skips leading whitespace, and reads and expands tokens,	   |
+| until it finds a comma or an right parenthesis at the same level of	   |
+| parentheses.  It returns a flag indicating whether the argument read are |
+| the last for the active macro call.  The argument are build on the	   |
+| obstack OBS, indirectly through expand_token ().			   |
+`-------------------------------------------------------------------------*/
+
+static bool
+expand_argument (struct obstack *obs, token_data *argp)
+{
+  token_type t;
+  token_data td;
+  char *text;
+  int paren_level;
+  const char *file = current_file;
+  int line = current_line;
+
+  TOKEN_DATA_TYPE (argp) = TOKEN_VOID;
+
+  /* Skip leading white space.  */
+  do
+    {
+      t = next_token (&td);
+    }
+  while (t == TOKEN_SIMPLE && isspace (to_uchar (*TOKEN_DATA_TEXT (&td))));
+
+  paren_level = 0;
+
+  while (1)
+    {
+
+      switch (t)
+	{			/* TOKSW */
+	case TOKEN_COMMA:
+	case TOKEN_CLOSE:
+	  if (paren_level == 0)
+	    {
+	      /* The argument MUST be finished, whether we want it or not.  */
+	      obstack_1grow (obs, '\0');
+	      text = (char *) obstack_finish (obs);
+
+	      if (TOKEN_DATA_TYPE (argp) == TOKEN_VOID)
+		{
+		  TOKEN_DATA_TYPE (argp) = TOKEN_TEXT;
+		  TOKEN_DATA_TEXT (argp) = text;
+		}
+	      return t == TOKEN_COMMA;
+	    }
+	  /* fallthru */
+	case TOKEN_OPEN:
+	case TOKEN_SIMPLE:
+	  text = TOKEN_DATA_TEXT (&td);
+
+	  if (*text == '(')
+	    paren_level++;
+	  else if (*text == ')')
+	    paren_level--;
+	  expand_token (obs, t, &td);
+	  break;
+
+	case TOKEN_EOF:
+	  /* current_file changed to "" if we see TOKEN_EOF, use the
+	     previous value we stored earlier.  */
+	  M4ERROR_AT_LINE ((EXIT_FAILURE, 0, file, line,
+			    "ERROR: end of file in argument list"));
+	  break;
+
+	case TOKEN_WORD:
+	case TOKEN_STRING:
+	  expand_token (obs, t, &td);
+	  break;
+
+	case TOKEN_MACDEF:
+	  if (obstack_object_size (obs) == 0)
+	    {
+	      TOKEN_DATA_TYPE (argp) = TOKEN_FUNC;
+	      TOKEN_DATA_FUNC (argp) = TOKEN_DATA_FUNC (&td);
+	    }
+	  break;
+
+	default:
+	  M4ERROR ((warning_status, 0,
+		    "INTERNAL ERROR: bad token type in expand_argument ()"));
+	  abort ();
+	}
+
+      t = next_token (&td);
+    }
+}
+
+/*-------------------------------------------------------------------------.
+| Collect all the arguments to a call of the macro SYM.  The arguments are |
+| stored on the obstack ARGUMENTS and a table of pointers to the arguments |
+| on the obstack ARGPTR.						   |
+`-------------------------------------------------------------------------*/
+
+static void
+collect_arguments (symbol *sym, struct obstack *argptr,
+		   struct obstack *arguments)
+{
+  token_data td;
+  token_data *tdp;
+  bool more_args;
+  bool groks_macro_args = SYMBOL_MACRO_ARGS (sym);
+
+  TOKEN_DATA_TYPE (&td) = TOKEN_TEXT;
+  TOKEN_DATA_TEXT (&td) = SYMBOL_NAME (sym);
+  tdp = (token_data *) obstack_copy (arguments, &td, sizeof td);
+  obstack_ptr_grow (argptr, tdp);
+
+  if (peek_token () == TOKEN_OPEN)
+    {
+      next_token (&td);		/* gobble parenthesis */
+      do
+	{
+	  more_args = expand_argument (arguments, &td);
+
+	  if (!groks_macro_args && TOKEN_DATA_TYPE (&td) == TOKEN_FUNC)
+	    {
+	      TOKEN_DATA_TYPE (&td) = TOKEN_TEXT;
+	      TOKEN_DATA_TEXT (&td) = (char *) "";
+	    }
+	  tdp = (token_data *) obstack_copy (arguments, &td, sizeof td);
+	  obstack_ptr_grow (argptr, tdp);
+	}
+      while (more_args);
+    }
+}
+
+
+/*------------------------------------------------------------------------.
+| The actual call of a macro is handled by call_macro ().  call_macro ()  |
+| is passed a symbol SYM, whose type is used to call either a builtin	  |
+| function, or the user macro expansion function expand_user_macro ()	  |
+| (lives in builtin.c).  There are ARGC arguments to the call, stored in  |
+| the ARGV table.  The expansion is left on the obstack EXPANSION.  Macro |
+| tracing is also handled here.						  |
+`------------------------------------------------------------------------*/
+
+void
+call_macro (symbol *sym, int argc, token_data **argv,
+		 struct obstack *expansion)
+{
+  switch (SYMBOL_TYPE (sym))
+    {
+    case TOKEN_FUNC:
+      (*SYMBOL_FUNC (sym)) (expansion, argc, argv);
+      break;
+
+    case TOKEN_TEXT:
+      expand_user_macro (expansion, sym, argc, argv);
+      break;
+
+    default:
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: bad symbol type in call_macro ()"));
+      abort ();
+    }
+}
+
+/*-------------------------------------------------------------------------.
+| The macro expansion is handled by expand_macro ().  It parses the	   |
+| arguments, using collect_arguments (), and builds a table of pointers to |
+| the arguments.  The arguments themselves are stored on a local obstack.  |
+| Expand_macro () uses call_macro () to do the call of the macro.	   |
+|									   |
+| Expand_macro () is potentially recursive, since it calls expand_argument |
+| (), which might call expand_token (), which might call expand_macro ().  |
+`-------------------------------------------------------------------------*/
+
+static void
+expand_macro (symbol *sym)
+{
+  struct obstack arguments;	/* Alternate obstack if argc_stack is busy.  */
+  unsigned argv_base;		/* Size of argv_stack on entry.  */
+  bool use_argc_stack = true;	/* Whether argc_stack is safe.  */
+  token_data **argv;
+  int argc;
+  struct obstack *expansion;
+  const char *expanded;
+  bool traced;
+  int my_call_id;
+
+  /* Report errors at the location where the open parenthesis (if any)
+     was found, but after expansion, restore global state back to the
+     location of the close parenthesis.  This is safe since we
+     guarantee that macro expansion does not alter the state of
+     current_file/current_line (dnl, include, and sinclude are special
+     cased in the input engine to ensure this fact).  */
+  const char *loc_open_file = current_file;
+  int loc_open_line = current_line;
+  const char *loc_close_file;
+  int loc_close_line;
+
+  SYMBOL_PENDING_EXPANSIONS (sym)++;
+  expansion_level++;
+  if (nesting_limit > 0 && expansion_level > nesting_limit)
+    M4ERROR ((EXIT_FAILURE, 0,
+	      "ERROR: recursion limit of %d exceeded, use -L<N> to change it",
+	      nesting_limit));
+
+  macro_call_id++;
+  my_call_id = macro_call_id;
+
+  traced = (debug_level & DEBUG_TRACE_ALL) || SYMBOL_TRACED (sym);
+
+  argv_base = obstack_object_size (&argv_stack);
+  if (obstack_object_size (&argc_stack) > 0)
+    {
+      /* We cannot use argc_stack if this is a nested invocation, and an
+	 outer invocation has an unfinished argument being
+	 collected.  */
+      obstack_init (&arguments);
+      use_argc_stack = false;
+    }
+
+  if (traced && (debug_level & DEBUG_TRACE_CALL))
+    trace_prepre (SYMBOL_NAME (sym), my_call_id);
+
+  collect_arguments (sym, &argv_stack,
+		     use_argc_stack ? &argc_stack : &arguments);
+
+  argc = ((obstack_object_size (&argv_stack) - argv_base)
+	  / sizeof (token_data *));
+  argv = (token_data **) ((char *) obstack_base (&argv_stack) + argv_base);
+
+  loc_close_file = current_file;
+  loc_close_line = current_line;
+  current_file = loc_open_file;
+  current_line = loc_open_line;
+
+  if (traced)
+    trace_pre (SYMBOL_NAME (sym), my_call_id, argc, argv);
+
+  expansion = push_string_init ();
+  call_macro (sym, argc, argv, expansion);
+  expanded = push_string_finish ();
+
+  if (traced)
+    trace_post (SYMBOL_NAME (sym), my_call_id, argc, argv, expanded);
+
+  current_file = loc_close_file;
+  current_line = loc_close_line;
+
+  --expansion_level;
+  --SYMBOL_PENDING_EXPANSIONS (sym);
+
+  if (SYMBOL_DELETED (sym))
+    free_symbol (sym);
+
+  if (use_argc_stack)
+    obstack_free (&argc_stack, argv[0]);
+  else
+    obstack_free (&arguments, NULL);
+  obstack_blank (&argv_stack, -argc * sizeof (token_data *));
+}
diff --git a/src/bin/m4/src/output.c b/src/bin/m4/src/output.c
new file mode 100644
index 0000000000..d482bf7504
--- /dev/null
+++ b/src/bin/m4/src/output.c
@@ -0,0 +1,815 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+#include "m4.h"
+
+#include <limits.h>
+#include <sys/stat.h>
+
+#include "gl_avltree_oset.h"
+
+/* Size of initial in-memory buffer size for diversions.  Small diversions
+   would usually fit in.  */
+#define INITIAL_BUFFER_SIZE 512
+
+/* Maximum value for the total of all in-memory buffer sizes for
+   diversions.  */
+#define MAXIMUM_TOTAL_SIZE (512 * 1024)
+
+/* Size of buffer size to use while copying files.  */
+#define COPY_BUFFER_SIZE (32 * 512)
+
+/* Output functions.  Most of the complexity is for handling cpp like
+   sync lines.
+
+   This code is fairly entangled with the code in input.c, and maybe it
+   belongs there?  */
+
+typedef struct temp_dir m4_temp_dir;
+
+/* When part of diversion_table, each struct m4_diversion either
+   represents an open file (zero size, non-NULL u.file), an in-memory
+   buffer (non-zero size, non-NULL u.buffer), or an unused placeholder
+   diversion (zero size, u is NULL, non-zero used indicates that a
+   file has been created).  When not part of diversion_table, u.next
+   is a pointer to the free_list chain.  */
+
+typedef struct m4_diversion m4_diversion;
+
+struct m4_diversion
+  {
+    union
+      {
+	FILE *file;		/* diversion file on disk */
+	char *buffer;		/* in-memory diversion buffer */
+	m4_diversion *next;	/* free-list pointer */
+      } u;
+    int divnum;			/* which diversion this represents */
+    int size;			/* usable size before reallocation */
+    int used;			/* used length in characters */
+  };
+
+/* Table of diversions 1 through INT_MAX.  */
+static gl_oset_t diversion_table;
+
+/* Diversion 0 (not part of diversion_table).  */
+static m4_diversion div0;
+
+/* Linked list of reclaimed diversion storage.  */
+static m4_diversion *free_list;
+
+/* Obstack from which diversion storage is allocated.  */
+static struct obstack diversion_storage;
+
+/* Total size of all in-memory buffer sizes.  */
+static int total_buffer_size;
+
+/* The number of the currently active diversion.  This variable is
+   maintained for the `divnum' builtin function.  */
+int current_diversion;
+
+/* Current output diversion, NULL if output is being currently discarded.  */
+static m4_diversion *output_diversion;
+
+/* Values of some output_diversion fields, cached out for speed.  */
+static FILE *output_file;	/* current value of (file) */
+static char *output_cursor;	/* current value of (buffer + used) */
+static int output_unused;	/* current value of (size - used) */
+
+/* Number of input line we are generating output for.  */
+int output_current_line;
+
+/* Temporary directory holding all spilled diversion files.  */
+static m4_temp_dir *output_temp_dir;
+
+
+
+/*------------------------.
+| Output initialization.  |
+`------------------------*/
+
+/* Callback for comparing list elements ELT1 and ELT2 for order in
+   diversion_table.  */
+static int
+cmp_diversion_CB (const void *elt1, const void *elt2)
+{
+  const m4_diversion *d1 = (const m4_diversion *) elt1;
+  const m4_diversion *d2 = (const m4_diversion *) elt2;
+  /* No need to worry about overflow, since we don't create diversions
+     with negative divnum.  */
+  return d1->divnum - d2->divnum;
+}
+
+/* Callback for comparing list element ELT against THRESHOLD.  */
+static bool
+threshold_diversion_CB (const void *elt, const void *threshold)
+{
+  const m4_diversion *div = (const m4_diversion *) elt;
+  /* No need to worry about overflow, since we don't create diversions
+     with negative divnum.  */
+  return div->divnum >= *(const int *) threshold;
+}
+
+void
+output_init (void)
+{
+  diversion_table = gl_oset_create_empty (GL_AVLTREE_OSET, cmp_diversion_CB);
+  div0.u.file = stdout;
+  output_diversion = &div0;
+  output_file = stdout;
+  obstack_init (&diversion_storage);
+}
+
+void
+output_exit (void)
+{
+  /* Order is important, since we may have registered cleanup_tmpfile
+     as an atexit handler, and it must not traverse stale memory.  */
+  gl_oset_t table = diversion_table;
+  diversion_table = NULL;
+  gl_oset_free (table);
+  obstack_free (&diversion_storage, NULL);
+}
+
+/* Clean up any temporary directory.  Designed for use as an atexit
+   handler, where it is not safe to call exit() recursively; so this
+   calls _exit if a problem is encountered.  */
+static void
+cleanup_tmpfile (void)
+{
+  /* Close any open diversions.  */
+  bool fail = false;
+
+  if (diversion_table)
+    {
+      const void *elt;
+      gl_oset_iterator_t iter = gl_oset_iterator (diversion_table);
+      while (gl_oset_iterator_next (&iter, &elt))
+	{
+	  m4_diversion *diversion = (m4_diversion *) elt;
+	  if (!diversion->size && diversion->u.file
+	      && close_stream_temp (diversion->u.file) != 0)
+	    {
+	      M4ERROR ((0, errno,
+			"cannot clean temporary file for diversion"));
+	      fail = true;
+	    }
+	}
+      gl_oset_iterator_free (&iter);
+    }
+
+  /* Clean up the temporary directory.  */
+  if (cleanup_temp_dir (output_temp_dir) != 0)
+    fail = true;
+  if (fail)
+    _exit (exit_failure);
+}
+
+/* Convert DIVNUM into a temporary file name for use in m4_tmp*.  */
+static const char *
+m4_tmpname (int divnum)
+{
+  static char *buffer;
+  static char *tail;
+  if (buffer == NULL)
+    {
+      tail = xasprintf ("%s/m4-%d", output_temp_dir->dir_name, INT_MAX);
+      buffer = obstack_copy0 (&diversion_storage, tail, strlen (tail));
+      free (tail);
+      tail = strrchr (buffer, '-') + 1;
+    }
+  sprintf (tail, "%d", divnum);
+  return buffer;
+}
+
+/* Create a temporary file for diversion DIVNUM open for reading and
+   writing in a secure temp directory.  The file will be automatically
+   closed and deleted on a fatal signal.  The file can be closed and
+   reopened with m4_tmpclose and m4_tmpopen; when finally done with
+   the file, close it with m4_tmpremove.  Exits on failure, so the
+   return value is always an open file.  */
+static FILE *
+m4_tmpfile (int divnum)
+{
+  const char *name;
+  FILE *file;
+
+  if (output_temp_dir == NULL)
+    {
+      errno = 0;
+      output_temp_dir = create_temp_dir ("m4-", NULL, true);
+      if (output_temp_dir == NULL)
+	M4ERROR ((EXIT_FAILURE, errno,
+		  "cannot create temporary file for diversion"));
+      atexit (cleanup_tmpfile);
+    }
+  name = m4_tmpname (divnum);
+  register_temp_file (output_temp_dir, name);
+  errno = 0;
+  file = fopen_temp (name, O_BINARY ? "wb+" : "w+");
+  if (file == NULL)
+    {
+      unregister_temp_file (output_temp_dir, name);
+      M4ERROR ((EXIT_FAILURE, errno,
+		"cannot create temporary file for diversion"));
+    }
+  else if (set_cloexec_flag (fileno (file), true) != 0)
+    M4ERROR ((warning_status, errno,
+	      "Warning: cannot protect diversion across forks"));
+  return file;
+}
+
+/* Reopen a temporary file for diversion DIVNUM for reading and
+   writing in a secure temp directory.  Exits on failure, so the
+   return value is always an open file.  */
+static FILE *
+m4_tmpopen (int divnum)
+{
+  const char *name = m4_tmpname (divnum);
+  FILE *file;
+
+  errno = 0;
+  file = fopen_temp (name, O_BINARY ? "ab+" : "a+");
+  if (file == NULL)
+    M4ERROR ((EXIT_FAILURE, errno,
+	      "cannot create temporary file for diversion"));
+  else if (set_cloexec_flag (fileno (file), true) != 0)
+    M4ERROR ((warning_status, errno,
+	      "Warning: cannot protect diversion across forks"));
+  return file;
+}
+
+/* Close, but don't delete, a temporary FILE.  */
+static int
+m4_tmpclose (FILE *file)
+{
+  return close_stream_temp (file);
+}
+
+/* Delete a closed temporary FILE for diversion DIVNUM.  */
+static int
+m4_tmpremove (int divnum)
+{
+  return cleanup_temp_file (output_temp_dir, m4_tmpname (divnum));
+}
+
+/*-----------------------------------------------------------------------.
+| Reorganize in-memory diversion buffers so the current diversion can	 |
+| accomodate LENGTH more characters without further reorganization.  The |
+| current diversion buffer is made bigger if possible.  But to make room |
+| for a bigger buffer, one of the in-memory diversion buffers might have |
+| to be flushed to a newly created temporary file.  This flushed buffer	 |
+| might well be the current one.					 |
+`-----------------------------------------------------------------------*/
+
+static void
+make_room_for (int length)
+{
+  int wanted_size;
+  m4_diversion *selected_diversion = NULL;
+
+  /* Compute needed size for in-memory buffer.  Diversions in-memory
+     buffers start at 0 bytes, then 512, then keep doubling until it is
+     decided to flush them to disk.  */
+
+  output_diversion->used = output_diversion->size - output_unused;
+
+  for (wanted_size = output_diversion->size;
+       wanted_size < output_diversion->used + length;
+       wanted_size = wanted_size == 0 ? INITIAL_BUFFER_SIZE : wanted_size * 2)
+    ;
+
+  /* Check if we are exceeding the maximum amount of buffer memory.  */
+
+  if (total_buffer_size - output_diversion->size + wanted_size
+      > MAXIMUM_TOTAL_SIZE)
+    {
+      int selected_used;
+      char *selected_buffer;
+      m4_diversion *diversion;
+      int count;
+      gl_oset_iterator_t iter;
+      const void *elt;
+
+      /* Find out the buffer having most data, in view of flushing it to
+	 disk.  Fake the current buffer as having already received the
+	 projected data, while making the selection.  So, if it is
+	 selected indeed, we will flush it smaller, before it grows.  */
+
+      selected_diversion = output_diversion;
+      selected_used = output_diversion->used + length;
+
+      iter = gl_oset_iterator (diversion_table);
+      while (gl_oset_iterator_next (&iter, &elt))
+	{
+	  diversion = (m4_diversion *) elt;
+	  if (diversion->used > selected_used)
+	    {
+	      selected_diversion = diversion;
+	      selected_used = diversion->used;
+	    }
+	}
+      gl_oset_iterator_free (&iter);
+
+      /* Create a temporary file, write the in-memory buffer of the
+	 diversion to this file, then release the buffer.  Zero the
+	 diversion before doing anything that can exit () (including
+	 m4_tmpfile), so that the atexit handler doesn't try to close
+	 a garbage pointer as a file.  */
+
+      selected_buffer = selected_diversion->u.buffer;
+      total_buffer_size -= selected_diversion->size;
+      selected_diversion->size = 0;
+      selected_diversion->u.file = NULL;
+      selected_diversion->u.file = m4_tmpfile (selected_diversion->divnum);
+
+      if (selected_diversion->used > 0)
+	{
+	  count = fwrite (selected_buffer, (size_t) selected_diversion->used,
+			  1, selected_diversion->u.file);
+	  if (count != 1)
+	    M4ERROR ((EXIT_FAILURE, errno,
+		      "ERROR: cannot flush diversion to temporary file"));
+	}
+
+      /* Reclaim the buffer space for other diversions.  */
+
+      free (selected_buffer);
+      selected_diversion->used = 1;
+    }
+
+  /* Reload output_file, just in case the flushed diversion was current.  */
+
+  if (output_diversion == selected_diversion)
+    {
+      /* The flushed diversion was current indeed.  */
+
+      output_file = output_diversion->u.file;
+      output_cursor = NULL;
+      output_unused = 0;
+    }
+  else
+    {
+      /* Close any selected file since it is not the current diversion.  */
+      if (selected_diversion)
+	{
+	  FILE *file = selected_diversion->u.file;
+	  selected_diversion->u.file = 0;
+	  if (m4_tmpclose (file) != 0)
+	    M4ERROR ((0, errno, "cannot close temporary file for diversion"));
+	}
+
+      /* The current buffer may be safely reallocated.  */
+      output_diversion->u.buffer
+	= xrealloc (output_diversion->u.buffer, (size_t) wanted_size);
+
+      total_buffer_size += wanted_size - output_diversion->size;
+      output_diversion->size = wanted_size;
+
+      output_cursor = output_diversion->u.buffer + output_diversion->used;
+      output_unused = wanted_size - output_diversion->used;
+    }
+}
+
+/*------------------------------------------------------------------------.
+| Output one character CHAR, when it is known that it goes to a diversion |
+| file or an in-memory diversion buffer.				  |
+`------------------------------------------------------------------------*/
+
+#define OUTPUT_CHARACTER(Char) \
+  if (output_file)							\
+    putc ((Char), output_file);						\
+  else if (output_unused == 0)						\
+    output_character_helper ((Char));					\
+  else									\
+    (output_unused--, *output_cursor++ = (Char))
+
+static void
+output_character_helper (int character)
+{
+  make_room_for (1);
+
+  if (output_file)
+    putc (character, output_file);
+  else
+    {
+      *output_cursor++ = character;
+      output_unused--;
+    }
+}
+
+/*------------------------------------------------------------------------.
+| Output one TEXT having LENGTH characters, when it is known that it goes |
+| to a diversion file or an in-memory diversion buffer.			  |
+`------------------------------------------------------------------------*/
+
+static void
+output_text (const char *text, int length)
+{
+  int count;
+
+  if (!output_file && length > output_unused)
+    make_room_for (length);
+
+  if (output_file)
+    {
+      count = fwrite (text, length, 1, output_file);
+      if (count != 1)
+	M4ERROR ((EXIT_FAILURE, errno, "ERROR: copying inserted file"));
+    }
+  else
+    {
+      memcpy (output_cursor, text, (size_t) length);
+      output_cursor += length;
+      output_unused -= length;
+    }
+}
+
+/*-------------------------------------------------------------------------.
+| Add some text into an obstack OBS, taken from TEXT, having LENGTH	   |
+| characters.  If OBS is NULL, rather output the text to an external file  |
+| or an in-memory diversion buffer.  If OBS is NULL, and there is no	   |
+| output file, the text is discarded.					   |
+|									   |
+| If we are generating sync lines, the output have to be examined, because |
+| we need to know how much output each input line generates.  In general,  |
+| sync lines are output whenever a single input lines generates several	   |
+| output lines, or when several input lines does not generate any output.  |
+`-------------------------------------------------------------------------*/
+
+void
+shipout_text (struct obstack *obs, const char *text, int length)
+{
+  static bool start_of_output_line = true;
+  char line[20];
+  const char *cursor;
+
+  /* If output goes to an obstack, merely add TEXT to it.  */
+
+  if (obs != NULL)
+    {
+      obstack_grow (obs, text, length);
+      return;
+    }
+
+  /* Do nothing if TEXT should be discarded.  */
+
+  if (output_diversion == NULL)
+    return;
+
+  /* Output TEXT to a file, or in-memory diversion buffer.  */
+
+  if (!sync_output)
+    switch (length)
+      {
+
+	/* In-line short texts.  */
+
+      case 8: OUTPUT_CHARACTER (*text); text++;
+      case 7: OUTPUT_CHARACTER (*text); text++;
+      case 6: OUTPUT_CHARACTER (*text); text++;
+      case 5: OUTPUT_CHARACTER (*text); text++;
+      case 4: OUTPUT_CHARACTER (*text); text++;
+      case 3: OUTPUT_CHARACTER (*text); text++;
+      case 2: OUTPUT_CHARACTER (*text); text++;
+      case 1: OUTPUT_CHARACTER (*text);
+      case 0:
+	return;
+
+	/* Optimize longer texts.  */
+
+      default:
+	output_text (text, length);
+      }
+  else
+    for (; length-- > 0; text++)
+      {
+	if (start_of_output_line)
+	  {
+	    start_of_output_line = false;
+	    output_current_line++;
+
+#ifdef DEBUG_OUTPUT
+	    printf ("DEBUG: cur %d, cur out %d\n",
+		    current_line, output_current_line);
+#endif
+
+	    /* Output a `#line NUM' synchronization directive if needed.
+	       If output_current_line was previously given a negative
+	       value (invalidated), rather output `#line NUM "FILE"'.  */
+
+	    if (output_current_line != current_line)
+	      {
+		sprintf (line, "#line %d", current_line);
+		for (cursor = line; *cursor; cursor++)
+		  OUTPUT_CHARACTER (*cursor);
+		if (output_current_line < 1 && current_file[0] != '\0')
+		  {
+		    OUTPUT_CHARACTER (' ');
+		    OUTPUT_CHARACTER ('"');
+		    for (cursor = current_file; *cursor; cursor++)
+		      OUTPUT_CHARACTER (*cursor);
+		    OUTPUT_CHARACTER ('"');
+		  }
+		OUTPUT_CHARACTER ('\n');
+		output_current_line = current_line;
+	      }
+	  }
+	OUTPUT_CHARACTER (*text);
+	if (*text == '\n')
+	  start_of_output_line = true;
+      }
+}
+
+/* Functions for use by diversions.  */
+
+/*--------------------------------------------------------------------------.
+| Make a file for diversion DIVNUM, and install it in the diversion table.  |
+| Grow the size of the diversion table as needed.			    |
+`--------------------------------------------------------------------------*/
+
+/* The number of possible diversions is limited only by memory and
+   available file descriptors (each overflowing diversion uses one).  */
+
+void
+make_diversion (int divnum)
+{
+  m4_diversion *diversion = NULL;
+
+  if (current_diversion == divnum)
+    return;
+
+  if (output_diversion)
+    {
+      if (!output_diversion->size && !output_diversion->u.file)
+	{
+	  if (!gl_oset_remove (diversion_table, output_diversion))
+	    error (EXIT_FAILURE, 0, "INTERNAL ERROR: make_diversion failed");
+	  output_diversion->u.next = free_list;
+	  output_diversion->used = 0;
+	  free_list = output_diversion;
+	}
+      else if (output_diversion->size)
+	output_diversion->used = output_diversion->size - output_unused;
+      else if (output_diversion->used)
+	{
+	  FILE *file = output_diversion->u.file;
+	  output_diversion->u.file = NULL;
+	  if (m4_tmpclose (file) != 0)
+	    M4ERROR ((0, errno, "cannot close temporary file for diversion"));
+	}
+      output_diversion = NULL;
+      output_file = NULL;
+      output_cursor = NULL;
+      output_unused = 0;
+    }
+
+  current_diversion = divnum;
+
+  if (divnum < 0)
+    return;
+
+  if (divnum == 0)
+    diversion = &div0;
+  else
+    {
+      const void *elt;
+      if (gl_oset_search_atleast (diversion_table, threshold_diversion_CB,
+				  &divnum, &elt))
+	{
+	  m4_diversion *temp = (m4_diversion *) elt;
+	  if (temp->divnum == divnum)
+	    diversion = temp;
+	}
+    }
+  if (diversion == NULL)
+    {
+      /* First time visiting this diversion.  */
+      if (free_list)
+	{
+	  diversion = free_list;
+	  free_list = diversion->u.next;
+	}
+      else
+	{
+	  diversion = (m4_diversion *) obstack_alloc (&diversion_storage,
+						      sizeof *diversion);
+	  diversion->size = 0;
+	  diversion->used = 0;
+	}
+      diversion->u.file = NULL;
+      diversion->divnum = divnum;
+      gl_oset_add (diversion_table, diversion);
+    }
+
+  output_diversion = diversion;
+  if (output_diversion->size)
+    {
+      output_cursor = output_diversion->u.buffer + output_diversion->used;
+      output_unused = output_diversion->size - output_diversion->used;
+    }
+  else
+    {
+      if (!output_diversion->u.file && output_diversion->used)
+	output_diversion->u.file = m4_tmpopen (output_diversion->divnum);
+      output_file = output_diversion->u.file;
+    }
+  output_current_line = -1;
+}
+
+/*-------------------------------------------------------------------.
+| Insert a FILE into the current output file, in the same manner     |
+| diversions are handled.  This allows files to be included, without |
+| having them rescanned by m4.					     |
+`-------------------------------------------------------------------*/
+
+void
+insert_file (FILE *file)
+{
+  char buffer[COPY_BUFFER_SIZE];
+  size_t length;
+
+  /* Optimize out inserting into a sink.  */
+
+  if (!output_diversion)
+    return;
+
+  /* Insert output by big chunks.  */
+
+  for (;;)
+    {
+      length = fread (buffer, 1, COPY_BUFFER_SIZE, file);
+      if (ferror (file))
+	M4ERROR ((EXIT_FAILURE, errno, "ERROR: reading inserted file"));
+      if (length == 0)
+	break;
+      output_text (buffer, length);
+    }
+}
+
+/*-------------------------------------------------------------------.
+| Insert DIVERSION (but not div0) into the current output file.  The |
+| diversion is NOT placed on the expansion obstack, because it must  |
+| not be rescanned.  When the file is closed, it is deleted by the   |
+| system.							     |
+`-------------------------------------------------------------------*/
+
+static void
+insert_diversion_helper (m4_diversion *diversion)
+{
+  /* Effectively undivert only if an output stream is active.  */
+  if (output_diversion)
+    {
+      if (diversion->size)
+	output_text (diversion->u.buffer, diversion->used);
+      else
+	{
+	  if (!diversion->u.file && diversion->used)
+	    diversion->u.file = m4_tmpopen (diversion->divnum);
+	  if (diversion->u.file)
+	    {
+	      rewind (diversion->u.file);
+	      insert_file (diversion->u.file);
+	    }
+	}
+
+      output_current_line = -1;
+    }
+
+  /* Return all space used by the diversion.  */
+  if (diversion->size)
+    {
+      free (diversion->u.buffer);
+      diversion->size = 0;
+      diversion->used = 0;
+    }
+  else
+    {
+      if (diversion->u.file)
+	{
+	  FILE *file = diversion->u.file;
+	  diversion->u.file = NULL;
+	  diversion->used = 0;
+	  if (m4_tmpclose (file) != 0)
+	    M4ERROR ((0, errno, "cannot clean temporary file for diversion"));
+	}
+      if (m4_tmpremove (diversion->divnum) != 0)
+	M4ERROR ((0, errno, "cannot clean temporary file for diversion"));
+    }
+  gl_oset_remove (diversion_table, diversion);
+  diversion->u.next = free_list;
+  free_list = diversion;
+}
+
+/*-------------------------------------------------------------------------.
+| Insert diversion number DIVNUM into the current output file.  The	   |
+| diversion is NOT placed on the expansion obstack, because it must not be |
+| rescanned.  When the file is closed, it is deleted by the system.	   |
+`-------------------------------------------------------------------------*/
+
+void
+insert_diversion (int divnum)
+{
+  const void *elt;
+
+  /* Do not care about nonexistent diversions, and undiverting stdout
+     or self is a no-op.  */
+  if (divnum <= 0 || current_diversion == divnum)
+    return;
+  if (gl_oset_search_atleast (diversion_table, threshold_diversion_CB,
+			      &divnum, &elt))
+    {
+      m4_diversion *diversion = (m4_diversion *) elt;
+      if (diversion->divnum == divnum)
+	insert_diversion_helper (diversion);
+    }
+}
+
+/*-------------------------------------------------------------------------.
+| Get back all diversions.  This is done just before exiting from main (), |
+| and from m4_undivert (), if called without arguments.			   |
+`-------------------------------------------------------------------------*/
+
+void
+undivert_all (void)
+{
+  const void *elt;
+  gl_oset_iterator_t iter = gl_oset_iterator (diversion_table);
+  while (gl_oset_iterator_next (&iter, &elt))
+    {
+      m4_diversion *diversion = (m4_diversion *) elt;
+      if (diversion->divnum != current_diversion)
+	insert_diversion_helper (diversion);
+    }
+  gl_oset_iterator_free (&iter);
+}
+
+/*-------------------------------------------------------------.
+| Produce all diversion information in frozen format on FILE.  |
+`-------------------------------------------------------------*/
+
+void
+freeze_diversions (FILE *file)
+{
+  int saved_number;
+  int last_inserted;
+  gl_oset_iterator_t iter;
+  const void *elt;
+
+  saved_number = current_diversion;
+  last_inserted = 0;
+  make_diversion (0);
+  output_file = file;		/* kludge in the frozen file */
+
+  iter = gl_oset_iterator (diversion_table);
+  while (gl_oset_iterator_next (&iter, &elt))
+    {
+      m4_diversion *diversion = (m4_diversion *) elt;;
+      if (diversion->size || diversion->u.file)
+	{
+	  if (diversion->size)
+	    fprintf (file, "D%d,%d\n", diversion->divnum, diversion->used);
+	  else
+	    {
+	      struct stat file_stat;
+	      fflush (diversion->u.file);
+	      if (fstat (fileno (diversion->u.file), &file_stat) < 0)
+		M4ERROR ((EXIT_FAILURE, errno, "cannot stat diversion"));
+	      if (file_stat.st_size < 0
+		  || file_stat.st_size != (unsigned long int) file_stat.st_size)
+		M4ERROR ((EXIT_FAILURE, 0, "diversion too large"));
+	      fprintf (file, "D%d,%lu", diversion->divnum,
+		       (unsigned long int) file_stat.st_size);
+	    }
+
+	  insert_diversion_helper (diversion);
+	  putc ('\n', file);
+
+	  last_inserted = diversion->divnum;
+	}
+    }
+  gl_oset_iterator_free (&iter);
+
+  /* Save the active diversion number, if not already.  */
+
+  if (saved_number != last_inserted)
+    fprintf (file, "D%d,0\n\n", saved_number);
+}
diff --git a/src/bin/m4/src/path.c b/src/bin/m4/src/path.c
new file mode 100644
index 0000000000..634b1ec641
--- /dev/null
+++ b/src/bin/m4/src/path.c
@@ -0,0 +1,193 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 2004, 2006 Free Software
+   Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* Handling of path search of included files via the builtins "include"
+   and "sinclude".  */
+
+#include "m4.h"
+
+struct includes
+{
+  struct includes *next;	/* next directory to search */
+  const char *dir;		/* directory */
+  int len;
+};
+
+typedef struct includes includes;
+
+static includes *dir_list;		/* the list of path directories */
+static includes *dir_list_end;		/* the end of same */
+static int dir_max_length;		/* length of longest directory name */
+
+
+void
+include_init (void)
+{
+  dir_list = NULL;
+  dir_list_end = NULL;
+  dir_max_length = 0;
+}
+
+void
+include_env_init (void)
+{
+  char *path;
+  char *path_end;
+  char *env_path;
+
+  if (no_gnu_extensions)
+    return;
+
+  env_path = getenv ("M4PATH");
+  if (env_path == NULL)
+    return;
+
+  env_path = xstrdup (env_path);
+  path = env_path;
+
+  do
+    {
+      path_end = strchr (path, ':');
+      if (path_end)
+	*path_end = '\0';
+      add_include_directory (path);
+      path = path_end + 1;
+    }
+  while (path_end);
+  free (env_path);
+}
+
+void
+add_include_directory (const char *dir)
+{
+  includes *incl;
+
+  if (no_gnu_extensions)
+    return;
+
+  if (*dir == '\0')
+    dir = ".";
+
+  incl = (includes *) xmalloc (sizeof (struct includes));
+  incl->next = NULL;
+  incl->len = strlen (dir);
+  incl->dir = xstrdup (dir);
+
+  if (incl->len > dir_max_length) /* remember len of longest directory */
+    dir_max_length = incl->len;
+
+  if (dir_list_end == NULL)
+    dir_list = incl;
+  else
+    dir_list_end->next = incl;
+  dir_list_end = incl;
+
+#ifdef DEBUG_INCL
+  fprintf (stderr, "add_include_directory (%s);\n", dir);
+#endif
+}
+
+/* Search for FILE, first in `.', then according to -I options.  If
+   successful, return the open file, and if RESULT is not NULL, set
+   *RESULT to a malloc'd string that represents the file found with
+   respect to the current working directory.  */
+
+FILE *
+m4_path_search (const char *file, char **result)
+{
+  FILE *fp;
+  includes *incl;
+  char *name;			/* buffer for constructed name */
+  int e;
+
+  if (result)
+    *result = NULL;
+
+  /* Reject empty file.  */
+  if (!*file)
+    {
+      errno = ENOENT;
+      return NULL;
+    }
+
+  /* Look in current working directory first.  */
+  fp = fopen (file, "r");
+  if (fp != NULL)
+    {
+      if (set_cloexec_flag (fileno (fp), true) != 0)
+	M4ERROR ((warning_status, errno,
+		  "Warning: cannot protect input file across forks"));
+      if (result)
+	*result = xstrdup (file);
+      return fp;
+    }
+
+  /* If file not found, and filename absolute, fail.  */
+  if (*file == '/' || no_gnu_extensions)
+    return NULL;
+  e = errno;
+
+  name = (char *) xmalloc (dir_max_length + 1 + strlen (file) + 1);
+
+  for (incl = dir_list; incl != NULL; incl = incl->next)
+    {
+      strncpy (name, incl->dir, incl->len);
+      name[incl->len] = '/';
+      strcpy (name + incl->len + 1, file);
+
+#ifdef DEBUG_INCL
+      fprintf (stderr, "m4_path_search (%s) -- trying %s\n", file, name);
+#endif
+
+      fp = fopen (name, "r");
+      if (fp != NULL)
+	{
+	  if (debug_level & DEBUG_TRACE_PATH)
+	    DEBUG_MESSAGE2 ("path search for `%s' found `%s'", file, name);
+	  if (set_cloexec_flag (fileno (fp), true) != 0)
+	    M4ERROR ((warning_status, errno,
+		      "Warning: cannot protect input file across forks"));
+	  if (result)
+	    *result = name;
+	  else
+	    free (name);
+	  errno = e;
+	  return fp;
+	}
+    }
+  free (name);
+  errno = e;
+  return fp;
+}
+
+#ifdef DEBUG_INCL
+
+static void M4_GNUC_UNUSED
+include_dump (void)
+{
+  includes *incl;
+
+  fprintf (stderr, "include_dump:\n");
+  for (incl = dir_list; incl != NULL; incl = incl->next)
+    fprintf (stderr, "\t%s\n", incl->dir);
+}
+
+#endif /* DEBUG_INCL */
diff --git a/src/bin/m4/src/stackovf.c b/src/bin/m4/src/stackovf.c
new file mode 100644
index 0000000000..2aae507643
--- /dev/null
+++ b/src/bin/m4/src/stackovf.c
@@ -0,0 +1,415 @@
+/* Detect stack overflow (when getrlimit and sigaction or sigvec are available)
+   Copyright (C) 1993, 1994, 2006 Free Software Foundation, Inc.
+   Jim Avera <jima@netcom.com>, October 1993.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+ */
+
+/* Compiled only when USE_STACKOVF is defined, which itself requires
+   getrlimit with the RLIMIT_STACK option, and support for alternate
+   signal stacks using either SVR4 or BSD interfaces.
+
+   This should compile on ANY system which supports either sigaltstack()
+   or sigstack(), with or without <siginfo.h> or another way to determine
+   the fault address.
+
+   There is no completely portable way to determine if a SIGSEGV signal
+   indicates a stack overflow.  The fault address can be used to infer
+   this.  However, the fault address is passed to the signal handler in
+   different ways on various systems.  One of three methods are used to
+   determine the fault address:
+
+      1. The siginfo parameter (with siginfo.h, i.e., SVR4).
+
+      2. 4th "addr" parameter (assumed if struct sigcontext is defined,
+	 i.e., SunOS 4.x/BSD).
+
+      3. None (if no method is available).  This case just prints a
+      message before aborting with a core dump.  That way the user at
+      least knows that it *might* be a recursion problem.
+
+   Jim Avera <jima@netcom.com> writes, on Tue, 5 Oct 93 19:27 PDT:
+
+      "I got interested finding out how a program could catch and
+      diagnose its own stack overflow, and ended up modifying m4 to do
+      this.  Now it prints a nice error message and exits.
+
+      How it works: SIGSEGV is caught using a separate signal stack.  The
+      signal handler declares a stack overflow if the fault address is
+      near the end of the stack region, or if the maximum VM address
+      space limit has been reached.  Otherwise, it returns to re-execute
+      the instruction with SIG_DFL set, so that any real bugs cause a
+      core dump as usual."
+
+   Jim Avera <jima@netcom.com> writes, on Fri, 24 Jun 94 12:14 PDT:
+
+      "The stack-overflow detection code would still be needed to avoid a
+      SIGSEGV abort if swap space was exhausted at the moment the stack
+      tried to grow.  This is probably unlikely to occur with the
+      explicit nesting limit option of GNU m4."
+
+   Jim Avera <jima@netcom.com> writes, on Wed, 6 Jul 1994 14:41 PDT:
+
+      "When a stack overflow occurs, a SIGSEGV signal is sent, which by
+      default aborts the process with a core dump.
+
+      The code in stackovf.c catches SIGSEGV using a separate signal
+      stack.  The signal handler determines whether or not the SIGSEGV
+      arose from a stack overflow.  If it is a stack overflow, an
+      external function is called (which, in m4, prints a message an
+      exits).  Otherwise the SIGSEGV represents an m4 bug, and the signal
+      is re-raised with SIG_DFL set, which results in an abort and core
+      dump in the usual way.  It seems important (to me) that internal m4
+      bugs not be reported as user recursion errors, or vice-versa."  */
+
+#include "m4.h"			/* stdlib.h, xmalloc() */
+
+#include <assert.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <signal.h>
+
+#if HAVE_SIGINFO_H
+# include <siginfo.h>
+#endif
+
+#ifndef SA_RESETHAND
+# define SA_RESETHAND 0
+#endif
+#ifndef SA_SIGINFO
+# define SA_SIGINFO 0
+#endif
+
+#ifndef SIGSTKSZ
+# define SIGSTKSZ 8192
+#endif
+
+/* If the trap address is within STACKOVF_DETECT bytes of the calculated
+   stack limit, we diagnose a stack overflow.  This must be large enough
+   to cover errors in our estimatation of the limit address, and to
+   account for the maximum size of local variables (the amount the
+   trapping reference might exceed the stack limit).  Also, some machines
+   may report an arbitrary address within the same page frame.
+   If the value is too large, we might call some other SIGSEGV a stack
+   overflow, masking a bug.  */
+
+#ifndef STACKOVF_DETECT
+# define STACKOVF_DETECT 16384
+#endif
+
+typedef void (*handler_t) (void);
+
+static const char *stackbot;
+static const char *stackend;
+static const char *arg0;
+static handler_t stackovf_handler;
+
+/* The following OS-independent procedure is called from the SIGSEGV
+   signal handler.  The signal handler obtains information about the trap
+   in an OS-dependent manner, and passes a parameter with the meanings as
+   explained below.
+
+   If the OS explicitly identifies a stack overflow trap, either pass
+   PARAM_STACKOVF if a stack overflow, or pass PARAM_NOSTACKOVF if not
+   (id est, it is a random bounds violation).  Otherwise, if the fault
+   address is available, pass the fault address.  Otherwise (if no
+   information is available), pass NULL.
+
+   Not given an explicit indication, we compare the fault address with
+   the estimated stack limit, and test to see if overall VM space is
+   exhausted.
+
+   If a stack overflow is identified, then the external *stackovf_handler
+   function is called, which should print an error message and exit.  If
+   it is NOT a stack overflow, then we silently abort with a core dump by
+   returning to re-raise the SIGSEGV with SIG_DFL set.  If indeterminate,
+   then we do not call *stackovf_handler, but instead print an ambiguous
+   message and abort with a core dump.  This only occurs on systems which
+   provide no information, but is better than nothing.  */
+
+#define PARAM_STACKOVF ((const char *) (1 + STACKOVF_DETECT))
+#define PARAM_NOSTACKOVF ((const char *) (2 + STACKOVF_DETECT))
+
+static void
+process_sigsegv (int signo, const char *p)
+{
+  long diff;
+  diff = (p - stackend);
+
+#ifdef DEBUG_STKOVF
+  {
+    char buf[140];
+
+    sprintf (buf, "process_sigsegv: p=%#lx stackend=%#lx diff=%ld bot=%#lx\n",
+	     (long) p, (long) stackend, (long) diff, (long) stackbot);
+    write (2, buf, strlen (buf));
+  }
+#endif
+
+  if (p != PARAM_NOSTACKOVF)
+    {
+      if ((long) sbrk (8192) == (long) -1)
+	{
+
+	  /* sbrk failed.  Assume the RLIMIT_VMEM prevents expansion even
+	     if the stack limit has not been reached.  */
+
+	  write (2, "VMEM limit exceeded?\n", 21);
+	  p = PARAM_STACKOVF;
+	}
+      if (diff >= -STACKOVF_DETECT && diff <= STACKOVF_DETECT)
+	{
+
+	  /* The fault address is "sufficiently close" to the stack lim.  */
+
+	  p = PARAM_STACKOVF;
+	}
+      if (p == PARAM_STACKOVF)
+	{
+
+	  /* We have determined that this is indeed a stack overflow.  */
+
+	  (*stackovf_handler) ();	/* should call exit() */
+	}
+    }
+  if (p == NULL)
+    {
+      const char *cp;
+
+      cp = "\
+Memory bounds violation detected (SIGSEGV).  Either a stack overflow\n\
+occurred, or there is a bug in ";
+      write (2, cp, strlen (cp));
+      write (2, arg0, strlen (arg0));
+      cp = ".  Check for possible infinite recursion.\n";
+      write (2, cp, strlen (cp));
+    }
+
+  /* Return to re-execute the instruction which caused the trap with
+     SIGSEGV set to SIG_DFL.  An abort with core dump should occur.  */
+
+  signal (signo, SIG_DFL);
+}
+
+#if HAVE_STRUCT_SIGACTION_SA_SIGACTION
+
+/* POSIX.  */
+
+static void
+sigsegv_handler (int signo, siginfo_t *ip, void *context)
+{
+  process_sigsegv
+    (signo, (ip != NULL
+	     && ip->si_signo == SIGSEGV ? (char *) ip->si_addr : NULL));
+}
+
+#elif HAVE_SIGINFO_T
+
+/* SVR4.  */
+
+static void
+sigsegv_handler (int signo, siginfo_t *ip)
+{
+  process_sigsegv
+    (signo, (ip != NULL
+	     && ip->si_signo == SIGSEGV ? (char *) ip->si_addr : NULL));
+}
+
+#elif HAVE_SIGCONTEXT
+
+/* SunOS 4.x (and BSD?).  (not tested) */
+
+static void
+sigsegv_handler (int signo, int code, struct sigcontext *scp, char *addr)
+{
+  process_sigsegv (signo, addr);
+}
+
+#else /* not HAVE_SIGCONTEXT */
+
+/* OS provides no information.  */
+
+static void
+sigsegv_handler (int signo)
+{
+  process_sigsegv (signo, NULL);
+}
+
+#endif /* not HAVE_SIGCONTEXT */
+
+/* Arrange to trap a stack-overflow and call a specified handler.  The
+   call is on a dedicated signal stack.
+
+   argv and envp are as passed to main().
+
+   If a stack overflow is not detected, then the SIGSEGV is re-raised
+   with action set to SIG_DFL, causing an abort and coredump in the usual
+   way.
+
+   Detection of a stack overflow depends on the trap address being near
+   the stack limit address.  The stack limit can not be directly
+   determined in a portable way, but we make an estimate based on the
+   address of the argv and environment vectors, their contents, and the
+   maximum stack size obtained using getrlimit.  */
+
+void
+setup_stackovf_trap (char *const *argv, char *const *envp, handler_t handler)
+{
+  struct rlimit rl;
+  rlim_t stack_len;
+  int grows_upward;
+  register char *const *v;
+  register char *p;
+#if HAVE_SIGACTION && defined SA_ONSTACK
+  struct sigaction act;
+#elif HAVE_SIGVEC && defined SV_ONSTACK
+  struct sigvec vec;
+#else
+
+Error - Do not know how to set up stack-ovf trap handler...
+
+#endif
+
+  arg0 = argv[0];
+  stackovf_handler = handler;
+
+  /* Calculate the approximate expected addr for a stack-ovf trap.  */
+
+  if (getrlimit (RLIMIT_STACK, &rl) < 0)
+    error (EXIT_FAILURE, errno, "getrlimit");
+  stack_len = (rl.rlim_cur < rl.rlim_max ? rl.rlim_cur : rl.rlim_max);
+  stackbot = (char *) argv;
+  grows_upward = ((char *) &stack_len > stackbot);
+  if (grows_upward)
+    {
+
+      /* Grows toward increasing addresses.  */
+
+      for (v = argv; (p = (char *) *v) != NULL; v++)
+	{
+	  if (p < stackbot)
+	    stackbot = p;
+	}
+      if ((char *) envp < stackbot)
+	stackbot = (char *) envp;
+      for (v = envp; (p = (char *) *v) != NULL; v++)
+	{
+	  if (p < stackbot)
+	    stackbot = p;
+	}
+      stackend = stackbot + stack_len;
+    }
+  else
+    {
+
+      /* The stack grows "downward" (toward decreasing addresses).  */
+
+      for (v = argv; (p = (char *) *v) != NULL; v++)
+	{
+	  if (p > stackbot)
+	    stackbot = p;
+	}
+      if ((char *) envp > stackbot)
+	stackbot = (char *) envp;
+      for (v = envp; (p = (char *) *v) != NULL; v++)
+	{
+	  if (p > stackbot)
+	    stackbot = p;
+	}
+      stackend = stackbot - stack_len;
+    }
+
+  /* Allocate a separate signal-handler stack.  */
+
+#if HAVE_SIGALTSTACK && (HAVE_SIGINFO_T || ! HAVE_SIGSTACK)
+
+  /* Use sigaltstack only if siginfo_t is available, unless there is no
+     choice.  */
+
+  {
+    stack_t ss;
+
+    ss.ss_size = SIGSTKSZ;
+    ss.ss_sp = xmalloc ((unsigned) ss.ss_size);
+    ss.ss_flags = 0;
+    if (sigaltstack (&ss, NULL) < 0)
+      {
+	/* Oops - sigaltstack exists but doesn't work.  We can't
+	   install the overflow detector, but should gracefully treat
+	   it as though sigaltstack doesn't exist.  For example, this
+	   happens when compiled with Linux 2.1 headers but run
+	   against Linux 2.0 kernel.  */
+	free (ss.ss_sp);
+	if (errno == ENOSYS)
+	  return;
+	error (EXIT_FAILURE, errno, "sigaltstack");
+      }
+  }
+
+#elif HAVE_SIGSTACK
+
+  {
+    struct sigstack ss;
+    char *stackbuf = xmalloc (2 * SIGSTKSZ);
+
+    ss.ss_sp = stackbuf + SIGSTKSZ;
+    ss.ss_onstack = 0;
+    if (sigstack (&ss, NULL) < 0)
+      {
+	/* Oops - sigstack exists but doesn't work.  We can't install
+	   the overflow detector, but should gracefully treat it as
+	   though sigstack doesn't exist.  For example, this happens
+	   when compiled with Linux 2.1 headers but run against Linux
+	   2.0 kernel.  */
+	free (stackbuf);
+	if (errno == ENOSYS)
+	  return;
+	error (EXIT_FAILURE, errno, "sigstack");
+      }
+  }
+
+#else /* not HAVE_SIGSTACK */
+
+Error - Do not know how to set up stack-ovf trap handler...
+
+#endif /* not HAVE_SIGSTACK */
+
+  /* Arm the SIGSEGV signal handler.  */
+
+#if HAVE_SIGACTION && defined SA_ONSTACK
+
+  sigaction (SIGSEGV, NULL, &act);
+# if HAVE_STRUCT_SIGACTION_SA_SIGACTION
+  act.sa_sigaction = sigsegv_handler;
+# else /* ! HAVE_STRUCT_SIGACTION_SA_SIGACTION */
+  act.sa_handler = (RETSIGTYPE (*) (int)) sigsegv_handler;
+# endif /* ! HAVE_STRUCT_SIGACTION_SA_SIGACTION */
+  sigemptyset (&act.sa_mask);
+  act.sa_flags = (SA_ONSTACK | SA_RESETHAND | SA_SIGINFO);
+  if (sigaction (SIGSEGV, &act, NULL) < 0)
+    error (EXIT_FAILURE, errno, "sigaction");
+
+#else /* ! HAVE_SIGACTION */
+
+  vec.sv_handler = (RETSIGTYPE (*) (int)) sigsegv_handler;
+  vec.sv_mask = 0;
+  vec.sv_flags = (SV_ONSTACK | SV_RESETHAND);
+  if (sigvec (SIGSEGV, &vec, NULL) < 0)
+    error (EXIT_FAILURE, errno, "sigvec");
+
+#endif /* ! HAVE_SIGACTION */
+
+}
diff --git a/src/bin/m4/src/symtab.c b/src/bin/m4/src/symtab.c
new file mode 100644
index 0000000000..4fadf884ac
--- /dev/null
+++ b/src/bin/m4/src/symtab.c
@@ -0,0 +1,403 @@
+/* GNU m4 -- A simple macro processor
+
+   Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2003, 2006 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301  USA
+*/
+
+/* This file handles all the low level work around the symbol table.  The
+   symbol table is a simple chained hash table.  Each symbol is described
+   by a struct symbol, which is placed in the hash table based upon the
+   symbol name.  Symbols that hash to the same entry in the table are
+   kept on a list, sorted by name.  As a special case, to facilitate the
+   "pushdef" and "popdef" builtins, a symbol can be several times in the
+   symbol table, one for each definition.  Since the name is the same,
+   all the entries for the symbol will be on the same list, and will
+   also, because the list is sorted, be adjacent.  All the entries for a
+   name are simply ordered on the list by age.  The current definition
+   will then always be the first found.  */
+
+#include "m4.h"
+#include <limits.h>
+
+#ifdef DEBUG_SYM
+/* When evaluating hash table performance, this profiling code shows
+   how many collisions were encountered.  */
+
+struct profile
+{
+  int entry; /* Number of times lookup_symbol called with this mode.  */
+  int comparisons; /* Number of times strcmp was called.  */
+  int misses; /* Number of times strcmp did not return 0.  */
+  long long bytes; /* Number of bytes compared.  */
+};
+
+static struct profile profiles[5];
+static symbol_lookup current_mode;
+
+/* On exit, show a profile of symbol table performance.  */
+static void
+show_profile (void)
+{
+  int i;
+  for (i = 0; i < 5; i++)
+    {
+      fprintf(stderr, "m4: lookup mode %d called %d times, %d compares, "
+	      "%d misses, %lld bytes\n",
+	      i, profiles[i].entry, profiles[i].comparisons,
+	      profiles[i].misses, profiles[i].bytes);
+    }
+}
+
+/* Like strcmp (S1, S2), but also track profiling statistics.  */
+static int
+profile_strcmp (const char *s1, const char *s2)
+{
+  int i = 1;
+  int result;
+  while (*s1 && *s1 == *s2)
+    {
+      s1++;
+      s2++;
+      i++;
+    }
+  result = (unsigned char) *s1 - (unsigned char) *s2;
+  profiles[current_mode].comparisons++;
+  if (result != 0)
+    profiles[current_mode].misses++;
+  profiles[current_mode].bytes += i;
+  return result;
+}
+
+# define strcmp profile_strcmp
+#endif /* DEBUG_SYM */
+
+
+/*----------------------------------------------------------------------.
+| Initialise the symbol table, by allocating the necessary storage, and |
+| zeroing all the entries.					        |
+`----------------------------------------------------------------------*/
+
+/* Pointer to symbol table.  */
+symbol **symtab;
+
+void
+symtab_init (void)
+{
+  size_t i;
+  symbol **s;
+
+  s = symtab = (symbol **) xnmalloc (hash_table_size, sizeof (symbol *));
+
+  for (i = 0; i < hash_table_size; i++)
+    s[i] = NULL;
+
+#ifdef DEBUG_SYM
+  {
+    int e = atexit(show_profile);
+    if (e != 0)
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: unable to show symtab profile"));
+  }
+#endif /* DEBUG_SYM */
+}
+
+/*--------------------------------------------------.
+| Return a hashvalue for a string, from GNU-emacs.  |
+`--------------------------------------------------*/
+
+static size_t
+hash (const char *s)
+{
+  register size_t val = 0;
+
+  register const char *ptr = s;
+  register char ch;
+
+  while ((ch = *ptr++) != '\0')
+    val = (val << 7) + (val >> (sizeof (val) * CHAR_BIT - 7)) + ch;
+  return val;
+}
+
+/*--------------------------------------------.
+| Free all storage associated with a symbol.  |
+`--------------------------------------------*/
+
+void
+free_symbol (symbol *sym)
+{
+  if (SYMBOL_PENDING_EXPANSIONS (sym) > 0)
+    SYMBOL_DELETED (sym) = true;
+  else
+    {
+      free (SYMBOL_NAME (sym));
+      if (SYMBOL_TYPE (sym) == TOKEN_TEXT)
+	free (SYMBOL_TEXT (sym));
+      free (sym);
+    }
+}
+
+/*-------------------------------------------------------------------.
+| Search in, and manipulation of the symbol table, are all done by   |
+| lookup_symbol ().  It basically hashes NAME to a list in the	     |
+| symbol table, and searches this list for the first occurrence of a |
+| symbol with the name.						     |
+|								     |
+| The MODE parameter determines what lookup_symbol () will do.  It   |
+| can either just do a lookup, do a lookup and insert if not	     |
+| present, do an insertion even if the name is already in the list,  |
+| delete the first occurrence of the name on the list, or delete all |
+| occurrences of the name on the list.				     |
+`-------------------------------------------------------------------*/
+
+symbol *
+lookup_symbol (const char *name, symbol_lookup mode)
+{
+  size_t h;
+  int cmp = 1;
+  symbol *sym, *prev;
+  symbol **spp;
+
+#if DEBUG_SYM
+  current_mode = mode;
+  profiles[mode].entry++;
+#endif /* DEBUG_SYM */
+
+  h = hash (name);
+  sym = symtab[h % hash_table_size];
+
+  for (prev = NULL; sym != NULL; prev = sym, sym = sym->next)
+    {
+      cmp = strcmp (SYMBOL_NAME (sym), name);
+      if (cmp >= 0)
+	break;
+    }
+
+  /* If just searching, return status of search.  */
+
+  if (mode == SYMBOL_LOOKUP)
+    return cmp == 0 ? sym : NULL;
+
+  /* Symbol not found.  */
+
+  spp = (prev != NULL) ?  &prev->next : &symtab[h % hash_table_size];
+
+  switch (mode)
+    {
+
+    case SYMBOL_INSERT:
+
+      /* If the name was found in the table, check whether it is still in
+	 use by a pending expansion.  If so, replace the table element with
+	 a new one; if not, just return the symbol.  If not found, just
+	 insert the name, and return the new symbol.  */
+
+      if (cmp == 0 && sym != NULL)
+	{
+	  if (SYMBOL_PENDING_EXPANSIONS (sym) > 0)
+	    {
+	      symbol *old = sym;
+	      SYMBOL_DELETED (old) = true;
+
+	      sym = (symbol *) xmalloc (sizeof (symbol));
+	      SYMBOL_TYPE (sym) = TOKEN_VOID;
+	      SYMBOL_TRACED (sym) = SYMBOL_TRACED (old);
+	      SYMBOL_NAME (sym) = xstrdup (name);
+	      SYMBOL_SHADOWED (sym) = false;
+	      SYMBOL_MACRO_ARGS (sym) = false;
+	      SYMBOL_BLIND_NO_ARGS (sym) = false;
+	      SYMBOL_DELETED (sym) = false;
+	      SYMBOL_PENDING_EXPANSIONS (sym) = 0;
+
+	      SYMBOL_NEXT (sym) = SYMBOL_NEXT (old);
+	      SYMBOL_NEXT (old) = NULL;
+	      (*spp) = sym;
+	    }
+	  return sym;
+	}
+      /* Fall through.  */
+
+    case SYMBOL_PUSHDEF:
+
+      /* Insert a name in the symbol table.  If there is already a symbol
+	 with the name, insert this in front of it, and mark the old
+	 symbol as "shadowed".  */
+
+      sym = (symbol *) xmalloc (sizeof (symbol));
+      SYMBOL_TYPE (sym) = TOKEN_VOID;
+      SYMBOL_TRACED (sym) = false;
+      SYMBOL_NAME (sym) = xstrdup (name);
+      SYMBOL_SHADOWED (sym) = false;
+      SYMBOL_MACRO_ARGS (sym) = false;
+      SYMBOL_BLIND_NO_ARGS (sym) = false;
+      SYMBOL_DELETED (sym) = false;
+      SYMBOL_PENDING_EXPANSIONS (sym) = 0;
+
+      SYMBOL_NEXT (sym) = *spp;
+      (*spp) = sym;
+
+      if (mode == SYMBOL_PUSHDEF && cmp == 0)
+	{
+	  SYMBOL_SHADOWED (SYMBOL_NEXT (sym)) = true;
+	  SYMBOL_TRACED (sym) = SYMBOL_TRACED (SYMBOL_NEXT (sym));
+	}
+      return sym;
+
+    case SYMBOL_DELETE:
+    case SYMBOL_POPDEF:
+
+      /* Delete occurrences of symbols with NAME.  SYMBOL_DELETE kills
+	 all definitions, SYMBOL_POPDEF kills only the first.
+	 However, if the last instance of a symbol is marked for
+	 tracing, reinsert a placeholder in the table.  And if the
+	 definition is still in use, let the caller free the memory
+	 after it is done with the symbol.  */
+
+      if (cmp != 0 || sym == NULL)
+	return NULL;
+      {
+	bool traced = false;
+	if (SYMBOL_NEXT (sym) != NULL
+	    && SYMBOL_SHADOWED (SYMBOL_NEXT (sym))
+	    && mode == SYMBOL_POPDEF)
+	  {
+	    SYMBOL_SHADOWED (SYMBOL_NEXT (sym)) = false;
+	    SYMBOL_TRACED (SYMBOL_NEXT (sym)) = SYMBOL_TRACED (sym);
+	  }
+	else
+	  traced = SYMBOL_TRACED (sym);
+	do
+	  {
+	    *spp = SYMBOL_NEXT (sym);
+	    free_symbol (sym);
+	    sym = *spp;
+	  }
+	while (*spp != NULL && SYMBOL_SHADOWED (*spp)
+	       && mode == SYMBOL_DELETE);
+	if (traced)
+	  {
+	    sym = (symbol *) xmalloc (sizeof (symbol));
+	    SYMBOL_TYPE (sym) = TOKEN_VOID;
+	    SYMBOL_TRACED (sym) = true;
+	    SYMBOL_NAME (sym) = xstrdup (name);
+	    SYMBOL_SHADOWED (sym) = false;
+	    SYMBOL_MACRO_ARGS (sym) = false;
+	    SYMBOL_BLIND_NO_ARGS (sym) = false;
+	    SYMBOL_DELETED (sym) = false;
+	    SYMBOL_PENDING_EXPANSIONS (sym) = 0;
+
+	    SYMBOL_NEXT (sym) = *spp;
+	    (*spp) = sym;
+	  }
+      }
+      return NULL;
+
+    default:
+      M4ERROR ((warning_status, 0,
+		"INTERNAL ERROR: invalid mode to symbol_lookup ()"));
+      abort ();
+    }
+}
+
+/*-----------------------------------------------------------------.
+| The following function is used for the cases where we want to do |
+| something to each and every symbol in the table.  The function   |
+| hack_all_symbols () traverses the symbol table, and calls a	   |
+| specified function FUNC for each symbol in the table.  FUNC is   |
+| called with a pointer to the symbol, and the DATA argument.	   |
+|								   |
+| FUNC may safely call lookup_symbol with mode SYMBOL_POPDEF or	   |
+| SYMBOL_LOOKUP, but any other mode can break the iteration.	   |
+`-----------------------------------------------------------------*/
+
+void
+hack_all_symbols (hack_symbol *func, void *data)
+{
+  size_t h;
+  symbol *sym;
+  symbol *next;
+
+  for (h = 0; h < hash_table_size; h++)
+    {
+      /* We allow func to call SYMBOL_POPDEF, which can invalidate
+	 sym, so we must grab the next element to traverse before
+	 calling func.  */
+      for (sym = symtab[h]; sym != NULL; sym = next)
+	{
+	  next = SYMBOL_NEXT (sym);
+	  func (sym, data);
+	}
+    }
+}
+
+#ifdef DEBUG_SYM
+
+static void symtab_print_list (int i);
+
+static void M4_GNUC_UNUSED
+symtab_debug (void)
+{
+  token_data td;
+  const char *text;
+  symbol *s;
+  int delete;
+  static int i;
+
+  while (next_token (&td) == TOKEN_WORD)
+    {
+      text = TOKEN_DATA_TEXT (&td);
+      if (*text == '_')
+	{
+	  delete = 1;
+	  text++;
+	}
+      else
+	delete = 0;
+
+      s = lookup_symbol (text, SYMBOL_LOOKUP);
+
+      if (s == NULL)
+	printf ("Name `%s' is unknown\n", text);
+
+      if (delete)
+	(void) lookup_symbol (text, SYMBOL_DELETE);
+      else
+	(void) lookup_symbol (text, SYMBOL_INSERT);
+    }
+  symtab_print_list (i++);
+}
+
+static void
+symtab_print_list (int i)
+{
+  symbol *sym;
+  size_t h;
+
+  printf ("Symbol dump #%d:\n", i);
+  for (h = 0; h < hash_table_size; h++)
+    for (sym = symtab[h]; sym != NULL; sym = sym->next)
+      printf ("\tname %s, bucket %lu, addr %p, next %p, "
+	      "flags%s%s%s, pending %d\n",
+	      SYMBOL_NAME (sym),
+	      (unsigned long int) h, sym, SYMBOL_NEXT (sym),
+	      SYMBOL_TRACED (sym) ? " traced" : "",
+	      SYMBOL_SHADOWED (sym) ? " shadowed" : "",
+	      SYMBOL_DELETED (sym) ? " deleted" : "",
+	      SYMBOL_PENDING_EXPANSIONS (sym));
+}
+
+#endif /* DEBUG_SYM */