Commit d315777b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'BUG_ON' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* 'BUG_ON' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  Remove MAYBE_BUILD_BUG_ON
  BUILD_BUG_ON: make it handle more cases
parents 5a05a6d7 1765e3a4
......@@ -249,7 +249,7 @@ static inline enum zone_type gfp_zone(gfp_t flags)
((1 << ZONES_SHIFT) - 1);
if (__builtin_constant_p(bit))
MAYBE_BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
else {
#ifdef CONFIG_DEBUG_VM
BUG_ON((GFP_ZONE_BAD >> bit) & 1);
......
......@@ -575,12 +575,6 @@ struct sysinfo {
char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
};
/* Force a compilation error if condition is true */
#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
/* Force a compilation error if condition is constant and true */
#define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
/* Force a compilation error if a constant expression is not a power of 2 */
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
......@@ -592,6 +586,32 @@ struct sysinfo {
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
/**
* BUILD_BUG_ON - break compile if a condition is true.
* @cond: the condition which the compiler should know is false.
*
* If you have some code which relies on certain constants being equal, or
* other compile-time-evaluated condition, you should use BUILD_BUG_ON to
* detect if someone changes it.
*
* The implementation uses gcc's reluctance to create a negative array, but
* gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
* to inline functions). So as a fallback we use the optimizer; if it can't
* prove the condition is false, it will cause a link error on the undefined
* "__build_bug_on_failed". This error message can be harder to track down
* though, hence the two different methods.
*/
#ifndef __OPTIMIZE__
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
#else
extern int __build_bug_on_failed;
#define BUILD_BUG_ON(condition) \
do { \
((void)sizeof(char[1 - 2*!!(condition)])); \
if (condition) __build_bug_on_failed = 1; \
} while(0)
#endif
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
......
......@@ -76,7 +76,7 @@ bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size);
\
_n = (long) &((ptr)->name##_end) \
- (long) &((ptr)->name##_begin); \
MAYBE_BUILD_BUG_ON(_n < 0); \
BUILD_BUG_ON(_n < 0); \
\
kmemcheck_mark_initialized(&((ptr)->name##_begin), _n); \
} while (0)
......
......@@ -109,7 +109,10 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
unsigned int fbit)
{
/* Did you forget to fix assumptions on max features? */
MAYBE_BUILD_BUG_ON(fbit >= 32);
if (__builtin_constant_p(fbit))
BUILD_BUG_ON(fbit >= 32);
else
BUG_ON(fbit >= 32);
if (fbit < VIRTIO_TRANSPORT_F_START)
virtio_check_driver_offered_feature(vdev, fbit);
......
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