mirror of
git://git.yoctoproject.org/linux-yocto.git
synced 2025-08-21 16:31:14 +02:00
e098eebb63
The current entrypoint attributes optimize("Os", "omit-frame-pointer")
are intended to avoid all compiler generated code, like function
porologue and epilogue.
This is the exact usecase implemented by the attribute "naked".
Unfortunately this is not implemented by GCC for all targets,
so only use it where available.
This also provides compatibility with clang, which recognizes the
"naked" attribute but not the previously used attribute "optimized".
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-6-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
36 lines
1.1 KiB
C
36 lines
1.1 KiB
C
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
|
|
/*
|
|
* NOLIBC compiler support header
|
|
* Copyright (C) 2023 Thomas Weißschuh <linux@weissschuh.net>
|
|
*/
|
|
#ifndef _NOLIBC_COMPILER_H
|
|
#define _NOLIBC_COMPILER_H
|
|
|
|
#if defined(__has_attribute)
|
|
# define __nolibc_has_attribute(attr) __has_attribute(attr)
|
|
#else
|
|
# define __nolibc_has_attribute(attr) 0
|
|
#endif
|
|
|
|
#if __nolibc_has_attribute(naked)
|
|
# define __nolibc_entrypoint __attribute__((naked))
|
|
# define __nolibc_entrypoint_epilogue()
|
|
#else
|
|
# define __nolibc_entrypoint __attribute__((optimize("Os", "omit-frame-pointer")))
|
|
# define __nolibc_entrypoint_epilogue() __builtin_unreachable()
|
|
#endif /* __nolibc_has_attribute(naked) */
|
|
|
|
#if defined(__SSP__) || defined(__SSP_STRONG__) || defined(__SSP_ALL__) || defined(__SSP_EXPLICIT__)
|
|
|
|
#define _NOLIBC_STACKPROTECTOR
|
|
|
|
#endif /* defined(__SSP__) ... */
|
|
|
|
#if __nolibc_has_attribute(no_stack_protector)
|
|
# define __no_stack_protector __attribute__((no_stack_protector))
|
|
#else
|
|
# define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
|
|
#endif /* __nolibc_has_attribute(no_stack_protector) */
|
|
|
|
#endif /* _NOLIBC_COMPILER_H */
|