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authorRusty Russell <rusty@rustcorp.com.au>2007-05-07 01:51:05 +0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-07 23:13:00 +0400
commitc5e631cf65f4d6875efcd571275436f2964a8b48 (patch)
tree1aee9d61560ee369b4a2f077a79e37ab868a4b2d /include/linux/compiler-gcc.h
parentf34d9d2dcb7f17b64124841345b23adc0843e7a5 (diff)
downloadlinux-c5e631cf65f4d6875efcd571275436f2964a8b48.tar.xz
ARRAY_SIZE: check for type
We can use a gcc extension to ensure that ARRAY_SIZE() is handed an array, not a pointer. This is especially important when code is changed from a fixed array to a pointer. I assume the Intel compiler doesn't support __builtin_types_compatible_p. [jdike@addtoit.com: uml: update UML definition of ARRAY_SIZE] Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/compiler-gcc.h')
-rw-r--r--include/linux/compiler-gcc.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 9008eabb9c3d..a9f794716a81 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -22,6 +22,9 @@
__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
(typeof(ptr)) (__ptr + (off)); })
+/* &a[0] degrades to a pointer: a different type from an array */
+#define __must_be_array(a) \
+ BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
#define inline inline __attribute__((always_inline))
#define __inline__ __inline__ __attribute__((always_inline))