#define LLVM_SUPPORT_ERRORHANDLING_H
#include "llvm/Support/Compiler.h"
+#include "llvm/ADT/StringRef.h"
#include <string>
namespace llvm {
/// standard error, followed by a newline.
/// After the error handler is called this function will call exit(1), it
/// does not return.
- NORETURN void report_fatal_error(const char *reason);
- NORETURN void report_fatal_error(const std::string &reason);
- NORETURN void report_fatal_error(const Twine &reason);
+ LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason);
+ LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const std::string &reason);
+ LLVM_ATTRIBUTE_NORETURN void report_fatal_error(StringRef reason);
+ LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const Twine &reason);
/// This function calls abort(), and prints the optional message to stderr.
/// Use the llvm_unreachable macro (that adds location info), instead of
/// calling this function directly.
- NORETURN void llvm_unreachable_internal(const char *msg=0,
- const char *file=0, unsigned line=0);
+ LLVM_ATTRIBUTE_NORETURN void llvm_unreachable_internal(const char *msg=0,
+ const char *file=0,
+ unsigned line=0);
}
-/// Prints the message and location info to stderr in !NDEBUG builds.
-/// This is intended to be used for "impossible" situations that imply
-/// a bug in the compiler.
+/// Marks that the current location is not supposed to be reachable.
+/// In !NDEBUG builds, prints the message and location info to stderr.
+/// In NDEBUG builds, becomes an optimizer hint that the current location
+/// is not supposed to be reachable. On compilers that don't support
+/// such hints, prints a reduced message instead.
///
-/// In NDEBUG mode it only prints "UNREACHABLE executed".
-/// Use this instead of assert(0), so that the compiler knows this path
-/// is not reachable even for NDEBUG builds.
+/// Use this instead of assert(0). It conveys intent more clearly and
+/// allows compilers to omit some unnecessary code.
#ifndef NDEBUG
#define llvm_unreachable(msg) \
::llvm::llvm_unreachable_internal(msg, __FILE__, __LINE__)
+#elif defined(LLVM_BUILTIN_UNREACHABLE)
+#define llvm_unreachable(msg) LLVM_BUILTIN_UNREACHABLE
#else
#define llvm_unreachable(msg) ::llvm::llvm_unreachable_internal()
#endif