llvm-6502/include/llvm/Support/ErrorHandling.h
Dan Gohman e16068240e Introduce a ScopedFatalErrorHandler class to make it easy to register
fatal error handlers which automatically get unregistered at the end
of a scope.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111398 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18 20:16:39 +00:00

101 lines
4.1 KiB
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//===- llvm/Support/ErrorHandling.h - Fatal error handling ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines an API used to indicate fatal error conditions. Non-fatal
// errors (most of them) should be handled through LLVMContext.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_ERRORHANDLING_H
#define LLVM_SUPPORT_ERRORHANDLING_H
#include "llvm/Support/Compiler.h"
#include <string>
namespace llvm {
class Twine;
/// An error handler callback.
typedef void (*fatal_error_handler_t)(void *user_data,
const std::string& reason);
/// 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.
///
/// 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 remove_fatal_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.
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);
/// 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);
}
/// 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::llvm_unreachable_internal(msg, __FILE__, __LINE__)
#else
#define llvm_unreachable(msg) ::llvm::llvm_unreachable_internal()
#endif
#endif