diff options
| author | Andi Kleen | 2005-09-13 01:25:13 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2005-09-13 08:22:28 -0700 |
| commit | 921717a2a1cde78c9b2aa971c16510d63efe7320 (patch) | |
| tree | 500ce20507a4c75e1e179492b7d70f2135e1ca94 /include | |
| parent | 0f3d2bd54f8fb178f516fc6903366e16e20f7428 (diff) | |
[PATCH] Make BUILD_BUG_ON fail at compile time.
Force a compiler error instead of a link error, because they are easier to
track down. Idea stolen from code by Jan Beulich <jbeulich@novell.com>
If the argument to BUILD_BUG_ON evaluates to non-zero the compiler will do:
t.c:6: error: size of array `type name' is negative
(surprised that gcc doesn't have an extension for this)
Signed-off-by: "Andi Kleen" <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kernel.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 687ba8c9973d..4367ce4db52a 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -307,8 +307,8 @@ struct sysinfo { char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */ }; -extern void BUILD_BUG(void); -#define BUILD_BUG_ON(condition) do { if (condition) BUILD_BUG(); } while(0) +/* Force a compilation error if condition is false */ +#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) #ifdef CONFIG_SYSCTL extern int randomize_va_space; |