ia64/xen-unstable

changeset 18909:1419a73316e1

Fix BUILD_BUG_ON()

As was noticed on the Linux side, using an array here isn't appropriate
if the condition is not a compile time constant - gcc allows such
arrays, and hence the intended effect of producing a compiler error is
not achieved in that case. Bit field widths do not know similar
language extensions, and hence always produce a compiler error.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Dec 11 11:19:01 2008 +0000 (2008-12-11)
parents 6401c9533ef5
children 147c646a2836
files xen/include/xen/lib.h
line diff
     1.1 --- a/xen/include/xen/lib.h	Wed Dec 10 14:05:41 2008 +0000
     1.2 +++ b/xen/include/xen/lib.h	Thu Dec 11 11:19:01 2008 +0000
     1.3 @@ -16,7 +16,7 @@ void __warn(char *file, int line);
     1.4  #define WARN_ON(p) do { if (p) WARN(); } while (0)
     1.5  
     1.6  /* Force a compilation error if condition is true */
     1.7 -#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2 * !!(condition)]))
     1.8 +#define BUILD_BUG_ON(condition) ((void)sizeof(struct { int:-!!(condition); }))
     1.9  
    1.10  #ifndef assert_failed
    1.11  #define assert_failed(p)                                        \