bianbu-repo-mirror/bianbu-linux-6.6
1
0
Fork 0
mirror of https://gitee.com/bianbu-linux/linux-6.6 synced 2025-04-24 14:07:52 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

compiler: introduce __used and __maybe_unused

Browse source 
__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>
This commit is contained in:
David Rientjes 2007-05-09 02:35:27 -07:00 • committed by Linus Torvalds
parent f7e4217b00
commit 0d7ebbbc6e
4 changed files with 25 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

1
include/linux/compiler-gcc.h
View file

@ -40,3 +40,4 @@
#define noinline __attribute__((noinline))
#define __attribute_pure__ __attribute__((pure))
#define __attribute_const__ __attribute__((__const__))
#define __maybe_unused __attribute__((unused))