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authorMarcelo Tosatti <mtosatti@redhat.com>2013-03-04 20:10:32 -0300
committerMarcelo Tosatti <mtosatti@redhat.com>2013-03-04 20:10:32 -0300
commitee2c25efdd46d7ed5605d6fe877bdf4b47a4ab2e (patch)
tree35890281e93e667a8e262d76ef250025eb30a8c1 /include/linux/bug.h
parent3ab66e8a455a4877889c65a848f2fb32be502f2c (diff)
parent6dbe51c251a327e012439c4772097a13df43c5b8 (diff)
Merge branch 'master' into queue
* master: (15791 commits) Linux 3.9-rc1 btrfs/raid56: Add missing #include <linux/vmalloc.h> fix compat_sys_rt_sigprocmask() SUNRPC: One line comment fix ext4: enable quotas before orphan cleanup ext4: don't allow quota mount options when quota feature enabled ext4: fix a warning from sparse check for ext4_dir_llseek ext4: convert number of blocks to clusters properly ext4: fix possible memory leak in ext4_remount() jbd2: fix ERR_PTR dereference in jbd2__journal_start metag: Provide dma_get_sgtable() metag: prom.h: remove declaration of metag_dt_memblock_reserve() metag: copy devicetree to non-init memory metag: cleanup metag_ksyms.c includes metag: move mm/init.c exports out of metag_ksyms.c metag: move usercopy.c exports out of metag_ksyms.c metag: move setup.c exports out of metag_ksyms.c metag: move kick.c exports out of metag_ksyms.c metag: move traps.c exports out of metag_ksyms.c metag: move irq enable out of irqflags.h on SMP ... Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Conflicts: arch/x86/kernel/kvmclock.c
Diffstat (limited to 'include/linux/bug.h')
-rw-r--r--include/linux/bug.h47
1 files changed, 26 insertions, 21 deletions
diff --git a/include/linux/bug.h b/include/linux/bug.h
index b1cf40de847e..7f4818673c41 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -2,6 +2,7 @@
#define _LINUX_BUG_H
#include <asm/bug.h>
+#include <linux/compiler.h>
enum bug_trap_type {
BUG_TRAP_TYPE_NONE = 0,
@@ -12,11 +13,12 @@ enum bug_trap_type {
struct pt_regs;
#ifdef __CHECKER__
-#define BUILD_BUG_ON_NOT_POWER_OF_2(n)
+#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
#define BUILD_BUG_ON_ZERO(e) (0)
#define BUILD_BUG_ON_NULL(e) ((void*)0)
#define BUILD_BUG_ON_INVALID(e) (0)
-#define BUILD_BUG_ON(condition)
+#define BUILD_BUG_ON_MSG(cond, msg) (0)
+#define BUILD_BUG_ON(condition) (0)
#define BUILD_BUG() (0)
#else /* __CHECKER__ */
@@ -39,29 +41,37 @@ struct pt_regs;
#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
/**
+ * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
+ * error message.
+ * @condition: the condition which the compiler should know is false.
+ *
+ * See BUILD_BUG_ON for description.
+ */
+#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
+
+/**
* BUILD_BUG_ON - break compile if a condition is true.
* @condition: 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
+ * some 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.
+ * The implementation uses gcc's reluctance to create a negative array, but gcc
+ * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
+ * inline functions). Luckily, in 4.3 they added the "error" function
+ * attribute just for this type of case. Thus, we use a negative sized array
+ * (should always create an error on gcc versions older than 4.4) and then call
+ * an undefined function with the error attribute (should always create an
+ * error on gcc 4.3 and later). If for some reason, neither creates a
+ * compile-time error, we'll still have a link-time error, which is harder to
+ * track down.
*/
#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)
+#define BUILD_BUG_ON(condition) \
+ BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
#endif
/**
@@ -71,12 +81,7 @@ extern int __build_bug_on_failed;
* build time, you should use BUILD_BUG to detect if it is
* unexpectedly used.
*/
-#define BUILD_BUG() \
- do { \
- extern void __build_bug_failed(void) \
- __linktime_error("BUILD_BUG failed"); \
- __build_bug_failed(); \
- } while (0)
+#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
#endif /* __CHECKER__ */