summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/bug.h28
-rw-r--r--include/linux/compiler.h26
2 files changed, 38 insertions, 16 deletions
diff --git a/include/linux/bug.h b/include/linux/bug.h
index dc11dc762fc..7f4818673c4 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -17,6 +17,7 @@ struct pt_regs;
#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_MSG(cond, msg) (0)
#define BUILD_BUG_ON(condition) (0)
#define BUILD_BUG() (0)
#else /* __CHECKER__ */
@@ -40,6 +41,15 @@ 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.
*
@@ -60,15 +70,8 @@ struct pt_regs;
#ifndef __OPTIMIZE__
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
#else
-#define BUILD_BUG_ON(condition) \
- do { \
- bool __cond = !!(condition); \
- extern void __build_bug_on_failed(void) \
- __compiletime_error("BUILD_BUG_ON failed"); \
- if (__cond) \
- __build_bug_on_failed(); \
- __compiletime_error_fallback(__cond); \
- } while (0)
+#define BUILD_BUG_ON(condition) \
+ BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
#endif
/**
@@ -78,12 +81,7 @@ struct pt_regs;
* build time, you should use BUILD_BUG to detect if it is
* unexpectedly used.
*/
-#define BUILD_BUG() \
- do { \
- extern void __build_bug_failed(void) \
- __compiletime_error("BUILD_BUG failed");\
- __build_bug_failed(); \
- } while (0)
+#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
#endif /* __CHECKER__ */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 423bb6bd660..10b8f23fab0 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -308,11 +308,35 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
#ifndef __compiletime_error
# define __compiletime_error(message)
# define __compiletime_error_fallback(condition) \
- do { ((void)sizeof(char[1 - 2*!!(condition)])); } while (0)
+ do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
#else
# define __compiletime_error_fallback(condition) do { } while (0)
#endif
+#define __compiletime_assert(condition, msg, prefix, suffix) \
+ do { \
+ bool __cond = !(condition); \
+ extern void prefix ## suffix(void) __compiletime_error(msg); \
+ if (__cond) \
+ prefix ## suffix(); \
+ __compiletime_error_fallback(__cond); \
+ } while (0)
+
+#define _compiletime_assert(condition, msg, prefix, suffix) \
+ __compiletime_assert(condition, msg, prefix, suffix)
+
+/**
+ * compiletime_assert - break build and emit msg if condition is false
+ * @condition: a compile-time constant condition to check
+ * @msg: a message to emit if condition is false
+ *
+ * In tradition of POSIX assert, this macro will break the build if the
+ * supplied condition is *false*, emitting the supplied error message if the
+ * compiler has support to do so.
+ */
+#define compiletime_assert(condition, msg) \
+ _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
+
/*
* Prevent the compiler from merging or refetching accesses. The compiler
* is also forbidden from reordering successive instances of ACCESS_ONCE(),