From 7daf1c9835672a1a0731bcac30e5ae9751273c58 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Thu, 9 Dec 2021 11:58:17 +0100 Subject: include: : 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 Link: https://lore.barebox.org/20211209105817.3518258-1-a.fatoum@pengutronix.de Signed-off-by: Sascha Hauer --- include/linux/build_bug.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include') 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 */ -- cgit v1.2.3