Sometimes we want to check some expressions correctness in compile-time without generating extra code. "(void)(e)" does not work if expression has side-effects. This patch introduces macro unused_expression() which helps in this situation. Cast to "long" required because sizeof does not work for bit-fields. Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx> --- include/linux/compiler.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 923d093..46fbda3 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -310,4 +310,6 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); */ #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) +#define unused_expression(e) ((void)(sizeof((__force long)(e)))) + #endif /* __LINUX_COMPILER_H */ -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
