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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.
#include "llvm/ADT/StringRef.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,
bool gen_crash_diag);
/// install_fatal_error_handler - Installs a new error handler to be used
/// whenever a serious (non-recoverable) error is encountered by LLVM.
/// 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 = nullptr);
/// Restores default error handling behaviour.
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 = nullptr) {
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.
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason,
bool gen_crash_diag = true);
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const std::string &reason,
bool gen_crash_diag = true);
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(StringRef reason,
bool gen_crash_diag = true);
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const Twine &reason,
bool gen_crash_diag = true);
/// 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.
llvm_unreachable_internal(const char *msg=nullptr, const char *file=nullptr,
unsigned line=0);
/// 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.
/// 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__)
#define llvm_unreachable(msg) LLVM_BUILTIN_UNREACHABLE
#define llvm_unreachable(msg) ::llvm::llvm_unreachable_internal()