# define __has_attribute(x) 0
#endif
+#ifndef __has_cpp_attribute
+# define __has_cpp_attribute(x) 0
+#endif
+
#ifndef __has_builtin
# define __has_builtin(x) 0
#endif
#define LLVM_THREAD_LOCAL
#endif
+/// \macro LLVM_FALLTHROUGH
+/// \brief Marks an empty statement preceding a deliberate switch fallthrough.
+#if __has_cpp_attribute(clang::fallthrough)
+#define LLVM_FALLTHROUGH [[clang::fallthrough]]
+#else
+#define LLVM_FALLTHROUGH
+#endif
+
#endif