1 files changed, 72 insertions, 12 deletions

diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h
index ff872dc2637c..f40bd2b04c29 100644
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -2,6 +2,8 @@
 #ifndef _TOOLS_LINUX_COMPILER_H_
 #define _TOOLS_LINUX_COMPILER_H_
 
+#ifndef __ASSEMBLY__
+
 #include <linux/compiler_types.h>
 
 #ifndef __compiletime_error
@@ -42,15 +44,65 @@
 # define __always_inline	inline __attribute__((always_inline))
 #endif
 
+#ifndef __always_unused
+#define __always_unused __attribute__((__unused__))
+#endif
+
+#ifndef __noreturn
+#define __noreturn __attribute__((__noreturn__))
+#endif
+
+#ifndef unreachable
+#define unreachable() __builtin_unreachable()
+#endif
+
 #ifndef noinline
 #define noinline
 #endif
 
+#ifndef __nocf_check
+#define __nocf_check __attribute__((nocf_check))
+#endif
+
+#ifndef __naked
+#define __naked __attribute__((__naked__))
+#endif
+
 /* Are two types/vars the same type (ignoring qualifiers)? */
 #ifndef __same_type
 # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
 #endif
 
+/*
+ * This returns a constant expression while determining if an argument is
+ * a constant expression, most importantly without evaluating the argument.
+ * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
+ */
+#define __is_constexpr(x) \
+	(sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
+
+/*
+ * Similar to statically_true() but produces a constant expression
+ *
+ * To be used in conjunction with macros, such as BUILD_BUG_ON_ZERO(),
+ * which require their input to be a constant expression and for which
+ * statically_true() would otherwise fail.
+ *
+ * This is a trade-off: const_true() requires all its operands to be
+ * compile time constants. Else, it would always returns false even on
+ * the most trivial cases like:
+ *
+ *   true || non_const_var
+ *
+ * On the opposite, statically_true() is able to fold more complex
+ * tautologies and will return true on expressions such as:
+ *
+ *   !(non_const_var * 8 % 4)
+ *
+ * For the general case, statically_true() is better.
+ */
+#define const_true(x) __builtin_choose_expr(__is_constexpr(x), x, false)
+
 #ifdef __ANDROID__
 /*
  * FIXME: Big hammer to get rid of tons of:
@@ -86,6 +138,10 @@
 # define __force
 #endif
 
+#ifndef __iomem
+# define __iomem
+#endif
+
 #ifndef __weak
 # define __weak			__attribute__((weak))
 #endif
@@ -98,14 +154,6 @@
 # define unlikely(x)		__builtin_expect(!!(x), 0)
 #endif
 
-#ifndef __init
-# define __init
-#endif
-
-#ifndef noinline
-# define noinline
-#endif
-
 #include <linux/types.h>
 
 /*
@@ -190,12 +238,24 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 })
 
 
-#ifndef __fallthrough
-# define __fallthrough
-#endif
-
 /* Indirect macros required for expanded argument pasting, eg. __LINE__. */
 #define ___PASTE(a, b) a##b
 #define __PASTE(a, b) ___PASTE(a, b)
 
+#ifndef OPTIMIZER_HIDE_VAR
+/* Make the optimizer believe the variable can be manipulated arbitrarily. */
+#define OPTIMIZER_HIDE_VAR(var)						\
+	__asm__ ("" : "=r" (var) : "0" (var))
+#endif
+
+#ifndef __BUILD_BUG_ON_ZERO_MSG
+#if defined(__clang__)
+#define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)(sizeof(struct { int:(-!!(e)); })))
+#else
+#define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)sizeof(struct {_Static_assert(!(e), msg);}))
+#endif
+#endif
+
+#endif /* __ASSEMBLY__ */
+
 #endif /* _TOOLS_LINUX_COMPILER_H */