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authorPaul Gortmaker <paul.gortmaker@windriver.com>2011-11-16 23:51:05 -0500
committerPaul Gortmaker <paul.gortmaker@windriver.com>2012-03-04 17:54:35 -0500
commit35edd9103c84f2b37f63227d12765c38f30495c5 (patch)
treefd8afa6aee69f6353f7d0d6f927c6c5c2a6ecdd4 /include/linux/kernel.h
parent187f1882b5b0748b3c4c22274663fdb372ac0452 (diff)
bug: consolidate BUILD_BUG_ON with other bug code
The support for BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h -- with this chunk off separate, you can run into situations where a person gets a compile fail even when they've included linux/bug.h, like this: CC lib/string.o lib/string.c: In function 'strlcat': lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON' make[2]: *** [lib/string.o] Error 1 $ $ grep linux/bug.h lib/string.c #include <linux/bug.h> $ Since the above violates the principle of least surprise, move the BUG chunks from kernel.h to bug.h so it is all together. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'include/linux/kernel.h')
-rw-r--r--include/linux/kernel.h61
1 files changed, 0 insertions, 61 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index e8343422240a..5dba983b8d65 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -662,67 +662,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
662 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 662 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
663 (type *)( (char *)__mptr - offsetof(type,member) );}) 663 (type *)( (char *)__mptr - offsetof(type,member) );})
664 664
665#ifdef __CHECKER__
666#define BUILD_BUG_ON_NOT_POWER_OF_2(n)
667#define BUILD_BUG_ON_ZERO(e) (0)
668#define BUILD_BUG_ON_NULL(e) ((void*)0)
669#define BUILD_BUG_ON(condition)
670#define BUILD_BUG() (0)
671#else /* __CHECKER__ */
672
673/* Force a compilation error if a constant expression is not a power of 2 */
674#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
675 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
676
677/* Force a compilation error if condition is true, but also produce a
678 result (of value 0 and type size_t), so the expression can be used
679 e.g. in a structure initializer (or where-ever else comma expressions
680 aren't permitted). */
681#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
682#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
683
684/**
685 * BUILD_BUG_ON - break compile if a condition is true.
686 * @condition: the condition which the compiler should know is false.
687 *
688 * If you have some code which relies on certain constants being equal, or
689 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
690 * detect if someone changes it.
691 *
692 * The implementation uses gcc's reluctance to create a negative array, but
693 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
694 * to inline functions). So as a fallback we use the optimizer; if it can't
695 * prove the condition is false, it will cause a link error on the undefined
696 * "__build_bug_on_failed". This error message can be harder to track down
697 * though, hence the two different methods.
698 */
699#ifndef __OPTIMIZE__
700#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
701#else
702extern int __build_bug_on_failed;
703#define BUILD_BUG_ON(condition) \
704 do { \
705 ((void)sizeof(char[1 - 2*!!(condition)])); \
706 if (condition) __build_bug_on_failed = 1; \
707 } while(0)
708#endif
709
710/**
711 * BUILD_BUG - break compile if used.
712 *
713 * If you have some code that you expect the compiler to eliminate at
714 * build time, you should use BUILD_BUG to detect if it is
715 * unexpectedly used.
716 */
717#define BUILD_BUG() \
718 do { \
719 extern void __build_bug_failed(void) \
720 __linktime_error("BUILD_BUG failed"); \
721 __build_bug_failed(); \
722 } while (0)
723
724#endif /* __CHECKER__ */
725
726/* Trap pasters of __FUNCTION__ at compile-time */ 665/* Trap pasters of __FUNCTION__ at compile-time */
727#define __FUNCTION__ (__func__) 666#define __FUNCTION__ (__func__)
728 667