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authorIngo Molnar <mingo@kernel.org>2012-04-13 09:50:21 +0200
committerIngo Molnar <mingo@kernel.org>2012-04-13 09:50:21 +0200
commit659c36fcda403013a01b85da07cf2d9711e6d6c7 (patch)
treeece2e7d0e2c19ea5a3d0ec172ad0b81a8a19021d /include/linux/bug.h
parent9521d830b6341d1887dcfc2aebde23fbfa5f1473 (diff)
parent5a7ed29c7572d00a75e8c4529e30c5ac2ef82271 (diff)
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Fixes and improvements for perf/core: . Overhaul the tools/ makefiles, gluing them to the top level Makefile, from Borislav Petkov. . Move the UI files from tools/perf/util/ui/ to tools/perf/ui/. Also move the GTK+ browser to tools/perf/ui/gtk/, from Namhyung Kim. . Only fallback to sw cycles counter on ENOENT for the hw cycles, from Robert Richter . Trivial fixes from Robert Richter . Handle the autogenerated bison/flex files better, from Namhyung and Jiri Olsa. . Navigate jump instructions in the annotate browser, just press enter or ->, still needs support for a jump navigation history, i.e. to go back. . Search string in the annotate browser: same keys as vim: / forward n next backward/forward ? backward . Clarify number of events/samples in the report header, from Ashay Rane Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/bug.h')
-rw-r--r--include/linux/bug.h61
1 files changed, 61 insertions, 0 deletions
diff --git a/include/linux/bug.h b/include/linux/bug.h
index d276b5510c8..72961c39576 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -11,6 +11,67 @@ enum bug_trap_type {
struct pt_regs;
+#ifdef __CHECKER__
+#define BUILD_BUG_ON_NOT_POWER_OF_2(n)
+#define BUILD_BUG_ON_ZERO(e) (0)
+#define BUILD_BUG_ON_NULL(e) ((void*)0)
+#define BUILD_BUG_ON(condition)
+#define BUILD_BUG() (0)
+#else /* __CHECKER__ */
+
+/* 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))
+
+/* Force a compilation error if condition is true, but also produce a
+ result (of value 0 and type size_t), so the expression can be used
+ e.g. in a structure initializer (or where-ever else comma expressions
+ aren't permitted). */
+#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.
+ * @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
+ * 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
+
+/**
+ * BUILD_BUG - break compile if used.
+ *
+ * If you have some code that you expect the compiler to eliminate at
+ * 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)
+
+#endif /* __CHECKER__ */
+
#ifdef CONFIG_GENERIC_BUG
#include <asm-generic/bug.h>