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author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2021-12-09 11:58:17 +0100 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2021-12-13 23:17:00 +0100 |
commit | 7daf1c9835672a1a0731bcac30e5ae9751273c58 (patch) | |
tree | 7c3bc34aa5b655a8d78a7101be007d6665f82147 /include | |
parent | 16a656139c27c5dc0cd51f06b105e82f78068ef5 (diff) | |
download | barebox-7daf1c9835672a1a0731bcac30e5ae9751273c58.tar.gz barebox-7daf1c9835672a1a0731bcac30e5ae9751273c58.tar.xz |
include: <linux/build_bug.h>: define static_assert
BUILD_BUG_ON can't be used outside of a function, unlike static_assert.
Import the macro definition.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20211209105817.3518258-1-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/build_bug.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/build_bug.h b/include/linux/build_bug.h index 43d1fd50d4..40cd504f63 100644 --- a/include/linux/build_bug.h +++ b/include/linux/build_bug.h @@ -80,4 +80,23 @@ #endif /* __CHECKER__ */ +/** + * static_assert - check integer constant expression at build time + * + * static_assert() is a wrapper for the C11 _Static_assert, with a + * little macro magic to make the message optional (defaulting to the + * stringification of the tested expression). + * + * Contrary to BUILD_BUG_ON(), static_assert() can be used at global + * scope, but requires the expression to be an integer constant + * expression (i.e., it is not enough that __builtin_constant_p() is + * true for expr). + * + * Also note that BUILD_BUG_ON() fails the build if the condition is + * true, while static_assert() fails the build if the expression is + * false. + */ +#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr) +#define __static_assert(expr, msg, ...) _Static_assert(expr, msg) + #endif /* _LINUX_BUILD_BUG_H */ |