Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1d6a0d19 authored by Daniel Santos's avatar Daniel Santos Committed by Linus Torvalds
Browse files

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



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: default avatarDaniel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ca623c91

include/linux/bug.h

+4 −3
Original line number Diff line number Diff line
@@ -59,8 +59,9 @@ struct pt_regs; 
extern int __build_bug_on_failed;

#define BUILD_BUG_ON(condition)					\

	do {							\

		((void)sizeof(char[1 - 2*!!(condition)]));	\

		if (condition) __build_bug_on_failed = 1;	\

		bool __cond = !!(condition);			\

		((void)sizeof(char[1 - 2 * __cond]));		\

		if (__cond) __build_bug_on_failed = 1;		\

	} while (0)

#endif