From: Thomas Weißschuh Date: Mon, 30 Sep 2024 05:35:19 +0000 (+0200) Subject: tools/nolibc: compiler: add macro __nolibc_fallthrough X-Git-Tag: v6.13-rc1~201^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=079ec6a3cf529d86c2895059eb8be1b36cc9fd72;p=thirdparty%2Fkernel%2Flinux.git tools/nolibc: compiler: add macro __nolibc_fallthrough Recent version of GCC and clang gained -Wimplicit-fallthrough, warning about implicit fall-through between switch labels. As nolibc does not control the compilation flags, this can trigger warnings for when built by the user. Make use of the "fallthrough" attribute to explicitly annotate the expected fall-throughs and silence the warning. Link: https://lore.kernel.org/r/20240930-nolibc-fallthrough-v2-1-2e8d10fe3430@weissschuh.net Signed-off-by: Thomas Weißschuh --- diff --git a/tools/include/nolibc/compiler.h b/tools/include/nolibc/compiler.h index 9bc6a706a3323..fa1f547e7f13d 100644 --- a/tools/include/nolibc/compiler.h +++ b/tools/include/nolibc/compiler.h @@ -32,4 +32,10 @@ # define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector"))) #endif /* __nolibc_has_attribute(no_stack_protector) */ +#if __nolibc_has_attribute(fallthrough) +# define __nolibc_fallthrough do { } while (0); __attribute__((fallthrough)) +#else +# define __nolibc_fallthrough do { } while (0) +#endif /* __nolibc_has_attribute(fallthrough) */ + #endif /* _NOLIBC_COMPILER_H */ diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h index c968dbbc4ef81..3892034198dd5 100644 --- a/tools/include/nolibc/stdio.h +++ b/tools/include/nolibc/stdio.h @@ -15,6 +15,7 @@ #include "stdarg.h" #include "stdlib.h" #include "string.h" +#include "compiler.h" #ifndef EOF #define EOF (-1) @@ -264,7 +265,7 @@ int vfprintf(FILE *stream, const char *fmt, va_list args) case 'p': *(out++) = '0'; *(out++) = 'x'; - /* fall through */ + __nolibc_fallthrough; default: /* 'x' and 'p' above */ u64toh_r(v, out); break;