From aaeadfcb02fea79141251cd3a9f872d6f47fc244 Mon Sep 17 00:00:00 2001
From: Alex Smith <alex@alex-smith.me.uk>
Date: Thu, 16 Aug 2012 17:38:01 +0100
Subject: [PATCH] Do a separate libgcc build for the kernel as well.

Turns out that libgcc is needed, for some reason building the kernel
with -O0 does not end up referencing libgcc but -O2 does. A separate
build of it is done with -mno-red-zone, same reason as for libsupc++.
Ended up being easy to rebuild with different CFLAGS: previously I'd
tried doing `CFLAGS="-mno-red-zone" make` in the libgcc dir which
didn't override, the correct way is `make CFLAGS="-mno-red-zone"`
---
 build/scripts/build_cross_tools_gcc4 | 30 ++++++++++++++++++----------
 configure                            | 23 ++++++++++++---------
 2 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/build/scripts/build_cross_tools_gcc4 b/build/scripts/build_cross_tools_gcc4
index 9397c7a96a..3298bf4826 100755
--- a/build/scripts/build_cross_tools_gcc4
+++ b/build/scripts/build_cross_tools_gcc4
@@ -33,7 +33,7 @@ x86_64-*)
 	# failure
 	binutilsConfigureArgs=""
 	gccConfigureArgs=""
-	kernelSupcxxFlags="-mno-red-zone"
+	kernelCcFlags="-mno-red-zone"
 	;;
 m68k-*)
 	binutilsConfigureArgs="--enable-multilib"
@@ -46,7 +46,7 @@ arm-*)
 *)
 	binutilsConfigureArgs="--disable-multilib"
 	gccConfigureArgs="--disable-multilib"
-	kernelSupcxxFlags=
+	kernelCcFlags=
 	;;
 esac
 
@@ -166,18 +166,26 @@ $MAKE $additionalMakeArgs install || {
 	exit 1
 }
 
-# build libsupc++ for the kernel if the target arch requires it
-if [ -n "$kernelSupcxxFlags" ]; then
-	cd $stdcxxObjDir
-	CFLAGS="-O2 $kernelSupcxxFlags" CXXFLAGS="-O2 $kernelSupcxxFlags" \
-		$gccSourceDir/libstdc++-v3/configure --prefix=$installDir \
-		--target=$haikuMachine --host=$haikuMachine --disable-shared \
-		--disable-multilib || exit 1
-	$MAKE $additionalMakeArgs -C libsupc++ || {
+# build libraries for the kernel if the target arch requires it
+if [ -n "$kernelCcFlags" ]; then
+	$MAKE -C $haikuMachine/libgcc clean
+	$MAKE -C $haikuMachine/libgcc CFLAGS="-g -O2 $kernelCcFlags" || {
+		echo "Error: Building kernel libgcc failed." >&2
+		exit 1
+	}
+
+	cp $haikuMachine/libgcc/libgcc.a \
+		$installDir/$haikuMachine/lib/libgcc-kernel.a || exit 1
+
+	$MAKE -C $haikuMachine/libstdc++-v3/libsupc++ clean
+	$MAKE -C $haikuMachine/libstdc++-v3/libsupc++ CFLAGS="-g -O2 $kernelCcFlags" \
+		CXXFLAGS="-g -O2 $kernelCcFlags" || {
 		echo "Error: Building kernel libsupc++ failed." >&2
 		exit 1
 	}
-	cp libsupc++/.libs/libsupc++.a $installDir/$haikuMachine/lib/libsupc++-kernel.a
+
+	cp $haikuMachine/libstdc++-v3/libsupc++/.libs/libsupc++.a \
+		$installDir/$haikuMachine/lib/libsupc++-kernel.a || exit 1
 fi
 
 # cleanup
diff --git a/configure b/configure
index 571f3a0647..f43bac6864 100755
--- a/configure
+++ b/configure
@@ -188,6 +188,17 @@ standard_gcc_settings()
 			HAIKU_STATIC_LIBSUPCXX=`$HAIKU_CC -print-file-name=libsupc++.a`
 			HAIKU_SHARED_LIBSUPCXX=`$HAIKU_CC -print-file-name=libsupc++.so`
 
+			# If the architecture has separate runtime libraries for the
+			# kernel, use them.
+			HAIKU_KERNEL_LIBGCC=`$HAIKU_CC -print-file-name=libgcc-kernel.a`
+			if [ $HAIKU_KERNEL_LIBGCC = libgcc-kernel.a ]; then
+				HAIKU_KERNEL_LIBGCC=$HAIKU_GCC_LIBGCC
+			fi
+			HAIKU_KERNEL_LIBSUPCXX=`$HAIKU_CC -print-file-name=libsupc++-kernel.a`
+			if [ $HAIKU_KERNEL_LIBSUPCXX = libsupc++-kernel.a ]; then
+				HAIKU_KERNEL_LIBSUPCXX=$HAIKU_STATIC_LIBSUPCXX
+			fi
+
 			local headers
 			if [ -d $gccdir/../../../../$HAIKU_GCC_MACHINE/include/c++/$HAIKU_GCC_RAW_VERSION ]; then
 				headers=$gccdir/../../../../$HAIKU_GCC_MACHINE/include/c++/$HAIKU_GCC_RAW_VERSION
@@ -240,23 +251,17 @@ standard_gcc_settings()
 				echo "Please download it from www.haiku-os.org...";
 				exit 1;
 			fi
+
+			HAIKU_KERNEL_LIBGCC=$HAIKU_GCC_LIBGCC
+			HAIKU_KERNEL_LIBSUPCXX=
 		;;
 	esac
 
 	if [ "$targetArch" = "x86_64" ]; then
-		# Kernel doesn't need libgcc, and has a special version of libsupc++
-		# built with the correct flags. Note: Should libgcc ever be needed for
-		# the x86_64 kernel, a separate build of it will be needed with
-		# -mno-red-zone, like for libsupc++.
-		HAIKU_KERNEL_LIBGCC=
-		HAIKU_KERNEL_LIBSUPCXX=`$HAIKU_CC -print-file-name=libsupc++-kernel.a`
-
 		# Boot loader is 32-bit, need the 32-bit libs.
 		HAIKU_BOOT_LIBGCC=`$HAIKU_CC -m32 -print-libgcc-file-name`
 		HAIKU_BOOT_LIBSUPCXX=`$HAIKU_CC -m32 -print-file-name=libsupc++.a`
 	else
-		HAIKU_KERNEL_LIBGCC=$HAIKU_GCC_LIBGCC
-		HAIKU_KERNEL_LIBSUPCXX=$HAIKU_STATIC_LIBSUPCXX
 		HAIKU_BOOT_LIBGCC=$HAIKU_GCC_LIBGCC
 		HAIKU_BOOT_LIBSUPCXX=$HAIKU_STATIC_LIBSUPCXX
 	fi