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Diffstat (limited to 'include/linux/compiler.h')
-rw-r--r--include/linux/compiler.h43
1 files changed, 40 insertions, 3 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index f430e4162f41..10b8f23fab0f 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -10,6 +10,7 @@
# define __force __attribute__((force))
# define __nocast __attribute__((nocast))
# define __iomem __attribute__((noderef, address_space(2)))
+# define __must_hold(x) __attribute__((context(x,1,1)))
# define __acquires(x) __attribute__((context(x,0,1)))
# define __releases(x) __attribute__((context(x,1,0)))
# define __acquire(x) __context__(x,1)
@@ -33,6 +34,7 @@ extern void __chk_io_ptr(const volatile void __iomem *);
# define __chk_user_ptr(x) (void)0
# define __chk_io_ptr(x) (void)0
# define __builtin_warning(x, y...) (1)
+# define __must_hold(x)
# define __acquires(x)
# define __releases(x)
# define __acquire(x) (void)0
@@ -42,6 +44,10 @@ extern void __chk_io_ptr(const volatile void __iomem *);
# define __rcu
#endif
+/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
+#define ___PASTE(a,b) a##b
+#define __PASTE(a,b) ___PASTE(a,b)
+
#ifdef __KERNEL__
#ifdef __GNUC__
@@ -164,6 +170,11 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
(typeof(ptr)) (__ptr + (off)); })
#endif
+/* Not-quite-unique ID. */
+#ifndef __UNIQUE_ID
+# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
+#endif
+
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
@@ -296,10 +307,36 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
#endif
#ifndef __compiletime_error
# define __compiletime_error(message)
+# define __compiletime_error_fallback(condition) \
+ do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
+#else
+# define __compiletime_error_fallback(condition) do { } while (0)
#endif
-#ifndef __linktime_error
-# define __linktime_error(message)
-#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(),