nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

bug.h: prevent double evaulation of `condition' in BUILD_BUG_ON

Browse source 
When calling BUILD_BUG_ON in an optimized build using gcc 4.3 and later,
the condition will be evaulated twice, possibily with side-effects.  This
patch eliminates that error.

[akpm@linux-foundation.org: tweak code layout]
Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Daniel Santos 2013-02-21 16:41:45 -08:00 committed by Linus Torvalds
parent ca623c914e
commit 1d6a0d19c8
1 changed files with 4 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

7
include/linux/bug.h
View file

@ -59,9 +59,10 @@ struct pt_regs;
extern int __build_bug_on_failed; extern int __build_bug_on_failed;
#define BUILD_BUG_ON(condition) \ #define BUILD_BUG_ON(condition) \
do { \ do { \
((void)sizeof(char[1 - 2*!!(condition)])); \ bool __cond = !!(condition); \
if (condition) __build_bug_on_failed = 1; \ ((void)sizeof(char[1 - 2 * __cond])); \
} while(0) if (__cond) __build_bug_on_failed = 1; \
} while (0)
#endif #endif
/** /**