+#define LLVM_ATTRIBUTE_NORETURN __declspec(noreturn)
+#else
+#define LLVM_ATTRIBUTE_NORETURN
+#endif
+
+// LLVM_EXTENSION - Support compilers where we have a keyword to suppress
+// pedantic diagnostics.
+#ifdef __GNUC__
+#define LLVM_EXTENSION __extension__
+#else
+#define LLVM_EXTENSION
+#endif
+
+// LLVM_ATTRIBUTE_DEPRECATED(decl, "message")
+#if __has_feature(attribute_deprecated_with_message)
+# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
+ decl __attribute__((deprecated(message)))
+#elif defined(__GNUC__)
+# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
+ decl __attribute__((deprecated))
+#elif defined(_MSC_VER)
+# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
+ __declspec(deprecated(message)) decl
+#else
+# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
+ decl
+#endif
+
+// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands
+// to an expression which states that it is undefined behavior for the
+// compiler to reach this point. Otherwise is not defined.
+#if defined(__clang__) || (__GNUC__ > 4) \
+ || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+# define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
+#endif
+
+// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression
+// which causes the program to exit abnormally.
+#if defined(__clang__) || (__GNUC__ > 4) \
+ || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
+# define LLVM_BUILTIN_TRAP __builtin_trap()