libroot: Replace memmove() with musl's.

Includes an optimization to use memcpy where possible, and protection
against aliasing undefined behavior.

Also clean up the Jamrules for the kernel's usage of musl methods.

src/system/boot/Jamfile

@@ -299,6 +299,7 @@ for platform in [ MultiBootSubDirSetup ] {
 									$(TARGET_KERNEL_ARCH_DIR) ] ;
 		}
 
+		SEARCH_SOURCE += [ FDirName $(SUBDIR) $(DOTDOT) libroot posix musl string ] ;
 		SEARCH_SOURCE += [ FDirName $(SUBDIR) $(DOTDOT) libroot posix string ] ;
 		SEARCH_SOURCE += [ FDirName $(SUBDIR) $(DOTDOT) libroot posix stdlib ] ;
 		SEARCH_SOURCE += [ FDirName $(SUBDIR) $(DOTDOT) libroot posix locale ] ;

src/system/kernel/lib/Jamfile

@@ -45,20 +45,13 @@ SEARCH_SOURCE += [ FDirName $(posixSources) string ] ;
 SEARCH_SOURCE += [ FDirName $(posixSources) sys ] ;
 SEARCH_SOURCE += [ FDirName $(posixSources) time ] ;
 SEARCH_SOURCE += [ FDirName $(posixSources) unistd ] ;
-SEARCH_SOURCE += [ FDirName $(gnuSources) ] ;
+SEARCH_SOURCE += [ FDirName $(posixSources) musl string ] ;
+#SEARCH_SOURCE += [ FDirName $(gnuSources) ] ;
 
 local muslSources =
 	ffs.c
 	rand.c
 	rand_r.c
-
-	memmem.c
-	stpcpy.c
-	strchrnul.c
-	strcspn.c
-	strpbrk.c
-	strspn.c
-	strstr.c
 	;
 
 SourceHdrs $(muslSources) :
@@ -76,12 +69,14 @@ KernelMergeObject kernel_lib_posix.o :
 	fcntl.cpp
 	poll.cpp
 	utime.c
+
 	# locale
 	ctype_loc.cpp
 	ctype_l.cpp
 	ctype.cpp
 	localeconv.cpp
 	LocaleData.cpp
+
 	# stdlib
 	abs.c
 	atoi.c
@@ -94,6 +89,7 @@ KernelMergeObject kernel_lib_posix.o :
 	strtoll.c
 	strtoul.c
 	strtoull.c
+
 	# sys
 	chmod.c
 	stat.c
@@ -101,13 +97,14 @@ KernelMergeObject kernel_lib_posix.o :
 	select.cpp
 	gettimeofday.c
 	uio.c
+
 	# time
 	time.c
+
 	# unistd
 	access.c
 	chown.c
 	close.c
-	#conf.c
 	directory.c
 	dup.c
 	ioctl.c
@@ -119,16 +116,21 @@ KernelMergeObject kernel_lib_posix.o :
 	truncate.c
 	usergroup.cpp
 	write.c
+
 	# string
 	memchr.c
 	memcmp.c
+	memmem.c
 	memmove.c
+	stpcpy.c
 	strcasecmp.c
 	strcasestr.c
 	strcat.c
 	strchr.c
+	strchrnul.c
 	strcmp.c
 	strcpy.c
+	strcspn.c
 	strdup.cpp
 	strerror.c
 	strlcat.c
@@ -139,7 +141,10 @@ KernelMergeObject kernel_lib_posix.o :
 	strncpy.cpp
 	strndup.cpp
 	strnlen.cpp
+	strpbrk.c
 	strrchr.c
+	strspn.c
+	strstr.c
 	strtok.c
 	strupr.c
 
@@ -149,7 +154,6 @@ KernelMergeObject kernel_lib_posix.o :
 
 SEARCH on [ FGristFiles $(muslSources) ] += [ FDirName $(posixSources) musl misc ] ;
 SEARCH on [ FGristFiles $(muslSources) ] += [ FDirName $(posixSources) musl prng ] ;
-SEARCH on [ FGristFiles $(muslSources) ] += [ FDirName $(posixSources) musl string ] ;
 
 # misc
 

src/system/libroot/posix/musl/string/Jamfile

@@ -11,6 +11,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 		MergeObject <$(architecture)>posix_musl_string.o :
 			memccpy.c
 			memmem.c
+			memmove.c
 			memrchr.c
 			stpcpy.c
 			stpncpy.c

src/system/libroot/posix/musl/string/memmove.c

@@ -0,0 +1,42 @@
+#include <string.h>
+#include <stdint.h>
+
+#if defined(__GNUC__) && __GNUC__ >= 4
+typedef __attribute__((__may_alias__)) size_t WT;
+#define WS (sizeof(WT))
+#endif
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+	char *d = dest;
+	const char *s = src;
+
+	if (d==s) return d;
+	if ((uintptr_t)s-(uintptr_t)d-n <= -2*n) return memcpy(d, s, n);
+
+	if (d<s) {
+#if defined(__GNUC__) && __GNUC__ >= 4
+		if ((uintptr_t)s % WS == (uintptr_t)d % WS) {
+			while ((uintptr_t)d % WS) {
+				if (!n--) return dest;
+				*d++ = *s++;
+			}
+			for (; n>=WS; n-=WS, d+=WS, s+=WS) *(WT *)d = *(WT *)s;
+		}
+#endif
+		for (; n; n--) *d++ = *s++;
+	} else {
+#if defined(__GNUC__) && __GNUC__ >= 4
+		if ((uintptr_t)s % WS == (uintptr_t)d % WS) {
+			while ((uintptr_t)(d+n) % WS) {
+				if (!n--) return dest;
+				d[n] = s[n];
+			}
+			while (n>=WS) n-=WS, *(WT *)(d+n) = *(WT *)(s+n);
+		}
+#endif
+		while (n) n--, d[n] = s[n];
+	}
+
+	return dest;
+}

src/system/libroot/posix/string/Jamfile

@@ -22,7 +22,6 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			bzero.c
 			memchr.c
 			memcmp.c
-			memmove.c
 			strcasecmp.c
 			strcasestr.c
 			strcat.c

src/system/libroot/posix/string/memmove.c

@@ -1,78 +0,0 @@
-/*
- * Copyright 2001, Travis Geiselbrecht. All rights reserved.
- * Distributed under the terms of the NewOS License.
- */
-
-
-#include <sys/types.h>
-#include <string.h>
-
-#if !_ASM_MEMCPY
-
-typedef int word;
-
-#define lsize sizeof(word)
-#define lmask (lsize - 1)
-
-
-void*
-memmove(void* dest, void const* src, size_t count)
-{
-	char* d = (char*)dest;
-	const char* s = (const char*)src;
-	int len;
-
-	if (count == 0 || dest == src)
-		return dest;
-
-	if ((long)d < (long)s) {
-		if (((long)d | (long)s) & lmask) {
-			// src and/or dest do not align on word boundary
-			if ((((long)d ^ (long)s) & lmask) || (count < lsize))
-				len = count; // copy the rest of the buffer with the byte mover
-			else
-				len = lsize - ((long)d & lmask); // move the ptrs up to a word boundary
-
-			count -= len;
-			for (; len > 0; len--)
-				*d++ = *s++;
-		}
-		for (len = count / lsize; len > 0; len--) {
-			*(word*)d = *(word*)s;
-			d += lsize;
-			s += lsize;
-		}
-		for (len = count & lmask; len > 0; len--)
-			*d++ = *s++;
-	} else {
-		d += count;
-		s += count;
-		if (((long)d | (long)s) & lmask) {
-			// src and/or dest do not align on word boundary
-			if ((((long)d ^ (long)s) & lmask) || (count <= lsize))
-				len = count;
-			else
-				len = ((long)d & lmask);
-
-			count -= len;
-			for (; len > 0; len--)
-				*--d = *--s;
-		}
-		for (len = count / lsize; len > 0; len--) {
-			d -= lsize;
-			s -= lsize;
-			*(word*)d = *(word*)s;
-		}
-		for (len = count & lmask; len > 0; len--)
-			*--d = *--s;
-	}
-
-	return dest;
-}
-
-#if defined(__arm__)
-void* __aeabi_memmove(void* dest, void const* src, size_t count)
-	__attribute__((__alias__("memmove")));
-#endif
-
-#endif

src/system/runtime_loader/Jamfile

@@ -52,6 +52,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			<src!system!libroot!posix!locale!$(architecture)>ctype_loc.o
 			<src!system!libroot!posix!locale!$(architecture)>LocaleData.o
 
+			<src!system!libroot!posix!musl!string!$(architecture)>memmove.o
 			<src!system!libroot!posix!musl!string!$(architecture)>strchrnul.o
 			<src!system!libroot!posix!musl!string!$(architecture)>strcspn.o
 			<src!system!libroot!posix!musl!string!$(architecture)>strpbrk.o
@@ -60,7 +61,6 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 
 			<src!system!libroot!posix!string!$(architecture)>memchr.o
 			<src!system!libroot!posix!string!$(architecture)>memcmp.o
-			<src!system!libroot!posix!string!$(architecture)>memmove.o
 			<src!system!libroot!posix!string!$(architecture)>strcasecmp.o
 			<src!system!libroot!posix!string!$(architecture)>strcat.o
 			<src!system!libroot!posix!string!$(architecture)>strchr.o