-//===- llvm/Support/ErrorHandling.h - Callbacks for errors ------*- C++ -*-===//
+//===- llvm/Support/ErrorHandling.h - Fatal error handling ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
//
-// This file defines an API used to indicate error conditions.
-// Callbacks can be registered for these errors through this API.
+// This file defines an API used to indicate fatal error conditions. Non-fatal
+// errors (most of them) should be handled through LLVMContext.
//
//===----------------------------------------------------------------------===//
#include <string>
namespace llvm {
+ class Twine;
+
/// An error handler callback.
- typedef void (*llvm_error_handler_t)(const std::string& reason);
+ typedef void (*fatal_error_handler_t)(void *user_data,
+ const std::string& reason);
- /// Installs a new error handler: this function will be called whenever a
- /// serious error is encountered by LLVM.
+ /// install_fatal_error_handler - Installs a new error handler to be used
+ /// whenever a serious (non-recoverable) error is encountered by LLVM.
+ ///
/// If you are using llvm_start_multithreaded, you should register the handler
/// before doing that.
///
/// If no error handler is installed the default is to print the error message
- /// to stderr, and call exit(1).
- /// If an error handler is installed then it is the handler's responsibility
- /// to log the message, it will no longer be printed to stderr.
- /// If the error handler returns, then exit(1) will be called.
- void llvm_install_error_handler(llvm_error_handler_t handler);
+ /// to stderr, and call exit(1). If an error handler is installed then it is
+ /// the handler's responsibility to log the message, it will no longer be
+ /// printed to stderr. If the error handler returns, then exit(1) will be
+ /// called.
+ ///
+ /// It is dangerous to naively use an error handler which throws an exception.
+ /// Even though some applications desire to gracefully recover from arbitrary
+ /// faults, blindly throwing exceptions through unfamiliar code isn't a way to
+ /// achieve this.
+ ///
+ /// \param user_data - An argument which will be passed to the install error
+ /// handler.
+ void install_fatal_error_handler(fatal_error_handler_t handler,
+ void *user_data = 0);
/// Restores default error handling behaviour.
/// This must not be called between llvm_start_multithreaded() and
/// llvm_stop_multithreaded().
- void llvm_remove_error_handler(void);
+ void remove_fatal_error_handler();
- /// Reports a serious error, calling any installed error handler.
+ /// ScopedFatalErrorHandler - This is a simple helper class which just
+ /// calls install_fatal_error_handler in its constructor and
+ /// remove_fatal_error_handler in its destructor.
+ struct ScopedFatalErrorHandler {
+ explicit ScopedFatalErrorHandler(fatal_error_handler_t handler,
+ void *user_data = 0) {
+ install_fatal_error_handler(handler, user_data);
+ }
+
+ ~ScopedFatalErrorHandler() { remove_fatal_error_handler(); }
+ };
+
+ /// Reports a serious error, calling any installed error handler. These
+ /// functions are intended to be used for error conditions which are outside
+ /// the control of the compiler (I/O errors, invalid user input, etc.)
+ ///
/// If no error handler is installed the default is to print the message to
/// standard error, followed by a newline.
/// After the error handler is called this function will call exit(1), it
/// does not return.
- void llvm_report_error(const std::string &reason) NORETURN;
+ 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(const Twine &reason);
/// This function calls abort(), and prints the optional message to stderr.
- /// Call this instead of assert(0), so that compiler knows the path is not
- /// reachable even for NDEBUG builds.
- void llvm_unreachable(const char *msg=0) NORETURN;
+ /// Use the llvm_unreachable macro (that adds location info), instead of
+ /// calling this function directly.
+ 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.
+///
+/// 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.
#ifndef NDEBUG
-#define LLVM_UNREACHABLE(msg) llvm_unreachable(msg)
+#define llvm_unreachable(msg) \
+ ::llvm::llvm_unreachable_internal(msg, __FILE__, __LINE__)
#else
-#define LLVM_UNREACHABLE(msg) llvm_unreachable()
+#define llvm_unreachable(msg) ::llvm::llvm_unreachable_internal()
#endif
#endif
-