From 8c87df457cb58fe75b9b893007917cf8095660a0 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 22 Sep 2009 16:43:52 -0700 Subject: BUILD_BUG_ON(): fix it and a couple of bogus uses of it gcc permitting variable length arrays makes the current construct used for BUILD_BUG_ON() useless, as that doesn't produce any diagnostic if the controlling expression isn't really constant. Instead, this patch makes it so that a bit field gets used here. Consequently, those uses where the condition isn't really constant now also need fixing. Note that in the gfp.h, kmemcheck.h, and virtio_config.h cases MAYBE_BUILD_BUG_ON() really just serves documentation purposes - even if the expression is compile time constant (__builtin_constant_p() yields true), the array is still deemed of variable length by gcc, and hence the whole expression doesn't have the intended effect. [akpm@linux-foundation.org: make arch/sparc/include/asm/vio.h compile] [akpm@linux-foundation.org: more nonsensical assertions in tpm.c..] Signed-off-by: Jan Beulich Cc: Andi Kleen Cc: Rusty Russell Cc: Catalin Marinas Cc: "David S. Miller" Cc: Rajiv Andrade Cc: Mimi Zohar Cc: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/virtio_config.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include/linux/virtio_config.h') diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index e547e3c8ee9..0093dd7c1d6 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -109,8 +109,7 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev, unsigned int fbit) { /* Did you forget to fix assumptions on max features? */ - if (__builtin_constant_p(fbit)) - BUILD_BUG_ON(fbit >= 32); + MAYBE_BUILD_BUG_ON(fbit >= 32); if (fbit < VIRTIO_TRANSPORT_F_START) virtio_check_driver_offered_feature(vdev, fbit); -- cgit v1.2.3