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| author | David Rientjes <rientjes@google.com> | 2007-05-09 02:35:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:56 -0700 |
| commit | 0d7ebbbc6eaa5539f78ab20ed6ff1725a4e332ef (patch) | |
| tree | ddef8183ac6440e96678fd4d1159ee86619e2a97 /include/linux/compiler-gcc4.h | |
| parent | f7e4217b007d1f73e7e3cf10ba4fea4a608c603f (diff) | |
| download | lwn-0d7ebbbc6eaa5539f78ab20ed6ff1725a4e332ef.tar.gz lwn-0d7ebbbc6eaa5539f78ab20ed6ff1725a4e332ef.zip | |
compiler: introduce __used and __maybe_unused
__used is defined to be __attribute__((unused)) for all pre-3.3 gcc
compilers to suppress warnings for unused functions because perhaps they
are referenced only in inline assembly. It is defined to be
__attribute__((used)) for gcc 3.3 and later so that the code is still
emitted for such functions.
__maybe_unused is defined to be __attribute__((unused)) for both function
and variable use if it could possibly be unreferenced due to the evaluation
of preprocessor macros. Function prototypes shall be marked with
__maybe_unused if the actual definition of the function is dependant on
preprocessor macros.
No update to compiler-intel.h is necessary because ICC supports both
__attribute__((used)) and __attribute__((unused)) as specified by the gcc
manual.
__attribute_used__ is deprecated and will be removed once all current
code is converted to using __used.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/compiler-gcc4.h')
| -rw-r--r-- | include/linux/compiler-gcc4.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index fd0cc7c4a636..a03e9398a6c2 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -12,7 +12,8 @@ # define __inline __inline __attribute__((always_inline)) #endif -#define __attribute_used__ __attribute__((__used__)) +#define __used __attribute__((__used__)) +#define __attribute_used__ __used /* deprecated */ #define __must_check __attribute__((warn_unused_result)) #define __compiler_offsetof(a,b) __builtin_offsetof(a,b) #define __always_inline inline __attribute__((always_inline)) |