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.

Signed-off-by: Daniel Santos <daniel.san...@pobox.com>
---
 include/linux/bug.h |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/bug.h b/include/linux/bug.h
index 1b2465d..98bdbb3d 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -58,8 +58,9 @@ 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
 
-- 
1.7.3.4

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