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authorDavid Rientjes <rientjes@google.com>2007-05-09 02:35:27 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-09 12:30:56 -0700
commit0d7ebbbc6eaa5539f78ab20ed6ff1725a4e332ef (patch)
treeddef8183ac6440e96678fd4d1159ee86619e2a97 /include/linux/compiler-gcc4.h
parentf7e4217b007d1f73e7e3cf10ba4fea4a608c603f (diff)
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.h3
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))