From 8d304a3740232f018fca19d529cbc8d13afac755 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Mon, 7 Feb 2022 17:23:47 +0100 Subject: [PATCH] tools/nolibc/string: export memset() and memmove() "clang -Os" and "gcc -Ofast" without -ffreestanding may ignore memset() and memmove(), hoping to provide their builtin equivalents, and finally not find them. Thus we must export these functions for these rare cases. Note that as they're set in their own sections, they will be eliminated by the linker if not used. In addition, they do not prevent gcc from identifying them and replacing them with the shorter "rep movsb" or "rep stosb" when relevant. Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney --- tools/include/nolibc/string.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h index c166158..4554b6f 100644 --- a/tools/include/nolibc/string.h +++ b/tools/include/nolibc/string.h @@ -47,7 +47,10 @@ void *_nolibc_memcpy_down(void *dst, const void *src, size_t len) return dst; } -static __attribute__((unused)) +/* might be ignored by the compiler without -ffreestanding, then found as + * missing. + */ +__attribute__((weak,unused,section(".text.nolibc_memmove"))) void *memmove(void *dst, const void *src, size_t len) { size_t dir, pos; @@ -75,7 +78,10 @@ void *memcpy(void *dst, const void *src, size_t len) return _nolibc_memcpy_up(dst, src, len); } -static __attribute__((unused)) +/* might be ignored by the compiler without -ffreestanding, then found as + * missing. + */ +__attribute__((weak,unused,section(".text.nolibc_memset"))) void *memset(void *dst, int b, size_t len) { char *p = dst; -- 2.7.4