diff options
| author | Vegard Nossum <vegard.nossum@oracle.com> | 2020-04-06 20:09:37 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-07 10:43:42 -0700 |
| commit | af9c5d2e3b355854ff0e4acfbfbfadcd5198a349 (patch) | |
| tree | 0773e3ed616da23129f891c4ecdcf7a4bc684a19 /include/linux/compiler.h | |
| parent | 889b3c1245de48ed0cacf7aebb25c489d3e4a3e9 (diff) | |
compiler.h: fix error in BUILD_BUG_ON() reporting
compiletime_assert() uses __LINE__ to create a unique function name. This
means that if you have more than one BUILD_BUG_ON() in the same source
line (which can happen if they appear e.g. in a macro), then the error
message from the compiler might output the wrong condition.
For this source file:
#include <linux/build_bug.h>
#define macro() \
BUILD_BUG_ON(1); \
BUILD_BUG_ON(0);
void foo()
{
macro();
}
gcc would output:
./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_9' declared with attribute error: BUILD_BUG_ON failed: 0
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
However, it was not the BUILD_BUG_ON(0) that failed, so it should say 1
instead of 0. With this patch, we use __COUNTER__ instead of __LINE__, so
each BUILD_BUG_ON() gets a different function name and the correct
condition is printed:
./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_0' declared with attribute error: BUILD_BUG_ON failed: 1
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200331112637.25047-1-vegard.nossum@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 5e88e7e33abe..034b0a644efc 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -347,7 +347,7 @@ static inline void *offset_to_ptr(const int *off) * compiler has support to do so. */ #define compiletime_assert(condition, msg) \ - _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) + _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) #define compiletime_assert_atomic_type(t) \ compiletime_assert(__native_word(t), \ |