4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
commit b5bf1733d6a391c4e90ea8f8468d83023be74a2a upstream.
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 <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: William Cohen <wcohen@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-qnpig0xfop4hwv6k4mv1wts5@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/include/linux/compiler.h | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -126,4 +126,13 @@ static __always_inline void __write_once
#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 */