| //===- llvm/Support/ErrorHandling.h - Fatal error handling ------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // 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" |
| |
| namespace llvm { |
| class StringRef; |
| class Twine; |
| |
| /// An error handler callback. |
| typedef void (*fatal_error_handler_t)(void *user_data, |
| const char *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 abort(), it |
| /// does not return. |
| /// NOTE: The std::string variant was removed to avoid a <string> dependency. |
| [[noreturn]] void report_fatal_error(const char *reason, |
| bool gen_crash_diag = true); |
| [[noreturn]] void report_fatal_error(StringRef reason, |
| bool gen_crash_diag = true); |
| [[noreturn]] void report_fatal_error(const Twine &reason, |
| bool gen_crash_diag = true); |
| |
| /// Installs a new bad alloc error handler that should be used whenever a |
| /// bad alloc error, e.g. failing malloc/calloc, is encountered by LLVM. |
| /// |
| /// The user can install a bad alloc handler, in order to define the behavior |
| /// in case of failing allocations, e.g. throwing an exception. Note that this |
| /// handler must not trigger any additional allocations itself. |
| /// |
| /// 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. |
| /// |
| /// |
| /// \param user_data - An argument which will be passed to the installed error |
| /// handler. |
| void install_bad_alloc_error_handler(fatal_error_handler_t handler, |
| void *user_data = nullptr); |
| |
| /// Restores default bad alloc error handling behavior. |
| void remove_bad_alloc_error_handler(); |
| |
| void install_out_of_memory_new_handler(); |
| |
| /// Reports a bad alloc error, calling any user defined bad alloc |
| /// error handler. In contrast to the generic 'report_fatal_error' |
| /// functions, this function might not terminate, e.g. the user |
| /// defined error handler throws an exception, but it won't return. |
| /// |
| /// Note: When throwing an exception in the bad alloc handler, make sure that |
| /// the following unwind succeeds, e.g. do not trigger additional allocations |
| /// in the unwind chain. |
| /// |
| /// If no error handler is installed (default), throws a bad_alloc exception |
| /// if LLVM is compiled with exception support. Otherwise prints the error |
| /// to standard error and calls abort(). |
| [[noreturn]] void report_bad_alloc_error(const char *Reason, |
| bool GenCrashDiag = 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. |
| [[noreturn]] void |
| 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 and aborts the program. |
| /// |
| /// 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 |
| |
| #endif |