From b5bf1733d6a391c4e90ea8f8468d83023be74a2a Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 8 Feb 2017 17:01:46 -0300 Subject: [PATCH] tools include: Add a __fallthrough statement For cases where implicit fall through case labels are intended, to let us inform that to gcc >= 7: CC /tmp/build/perf/util/string.o util/string.c: In function 'perf_atoll': util/string.c:22:7: error: this statement may fall through [-Werror=implicit-fallthrough=] if (*p) ^ util/string.c:24:3: note: here case '\0': ^~~~ So we introduce: #define __fallthrough __attribute__ ((fallthrough)) And use it in such cases. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Cc: William Cohen Link: http://lkml.kernel.org/n/tip-qnpig0xfop4hwv6k4mv1wts5@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/compiler.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index e33fc1df3935..d94179f94caa 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -126,4 +126,13 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s #define WRITE_ONCE(x, val) \ ({ union { typeof(x) __val; char __c[1]; } __u = { .__val = (val) }; __write_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) + +#ifndef __fallthrough +# if defined(__GNUC__) && __GNUC__ >= 7 +# define __fallthrough __attribute__ ((fallthrough)) +# else +# define __fallthrough +# endif +#endif + #endif /* _TOOLS_LINUX_COMPILER_H */