From c5e631cf65f4d6875efcd571275436f2964a8b48 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 6 May 2007 14:51:05 -0700 Subject: 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 Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/compiler-gcc.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/compiler-gcc.h') 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)) -- cgit v1.2.3