Messages in this thread Patch in this message | | | Date | Fri, 02 Nov 2012 14:47:40 +0000 | From | "Jan Beulich" <> | Subject | [PATCH] utilize _Static_assert() for BUILD_BUG_ON() when the compiler supports it |
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This makes the resulting diagnostics quite a bit more useful.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- include/linux/bug.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
--- 3.7-rc3/include/linux/bug.h +++ 3.7-rc3-static-assert/include/linux/bug.h @@ -27,8 +27,15 @@ struct pt_regs; result (of value 0 and type size_t), so the expression can be used e.g. in a structure initializer (or where-ever else comma expressions aren't permitted). */ +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) +#define BUILD_BUG_ON_ZERO(e) \ + sizeof(struct { _Static_assert(!(e), "!(" #e ")"); }) +#define BUILD_BUG_ON_NULL(e) \ + ((void *)sizeof(struct { _Static_assert(!(e), "!(" #e ")"); })) +#else #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) +#endif /* * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the @@ -54,6 +61,15 @@ struct pt_regs; */ #ifndef __OPTIMIZE__ #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) +#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) +#define __build_bug_on_failed(n) __build_bug_on_##n##_failed +#define _BUILD_BUG_ON(n, condition) \ + do { \ + extern void __compiletime_error(#condition) \ + __build_bug_on_failed(n)(void); \ + if (condition) __build_bug_on_failed(n)(); \ + } while(0) +#define BUILD_BUG_ON(condition...) _BUILD_BUG_ON(__COUNTER__, ##condition) #else extern int __build_bug_on_failed; #define BUILD_BUG_ON(condition) \
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