ErrorHandling.cpp revision 353358
1//===- lib/Support/ErrorHandling.cpp - Callbacks for errors ---------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file defines an API used to indicate fatal error conditions. Non-fatal 10// errors (most of them) should be handled through LLVMContext. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/Support/ErrorHandling.h" 15#include "llvm-c/ErrorHandling.h" 16#include "llvm/ADT/SmallVector.h" 17#include "llvm/ADT/Twine.h" 18#include "llvm/Config/config.h" 19#include "llvm/Support/Debug.h" 20#include "llvm/Support/Errc.h" 21#include "llvm/Support/Error.h" 22#include "llvm/Support/Signals.h" 23#include "llvm/Support/Threading.h" 24#include "llvm/Support/WindowsError.h" 25#include "llvm/Support/raw_ostream.h" 26#include <cassert> 27#include <cstdlib> 28#include <mutex> 29#include <new> 30 31#if defined(HAVE_UNISTD_H) 32# include <unistd.h> 33#endif 34#if defined(_MSC_VER) 35# include <io.h> 36# include <fcntl.h> 37#endif 38 39using namespace llvm; 40 41static fatal_error_handler_t ErrorHandler = nullptr; 42static void *ErrorHandlerUserData = nullptr; 43 44static fatal_error_handler_t BadAllocErrorHandler = nullptr; 45static void *BadAllocErrorHandlerUserData = nullptr; 46 47#if LLVM_ENABLE_THREADS == 1 48// Mutexes to synchronize installing error handlers and calling error handlers. 49// Do not use ManagedStatic, or that may allocate memory while attempting to 50// report an OOM. 51// 52// This usage of std::mutex has to be conditionalized behind ifdefs because 53// of this script: 54// compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh 55// That script attempts to statically link the LLVM symbolizer library with the 56// STL and hide all of its symbols with 'opt -internalize'. To reduce size, it 57// cuts out the threading portions of the hermetic copy of libc++ that it 58// builds. We can remove these ifdefs if that script goes away. 59static std::mutex ErrorHandlerMutex; 60static std::mutex BadAllocErrorHandlerMutex; 61#endif 62 63void llvm::install_fatal_error_handler(fatal_error_handler_t handler, 64 void *user_data) { 65#if LLVM_ENABLE_THREADS == 1 66 std::lock_guard<std::mutex> Lock(ErrorHandlerMutex); 67#endif 68 assert(!ErrorHandler && "Error handler already registered!\n"); 69 ErrorHandler = handler; 70 ErrorHandlerUserData = user_data; 71} 72 73void llvm::remove_fatal_error_handler() { 74#if LLVM_ENABLE_THREADS == 1 75 std::lock_guard<std::mutex> Lock(ErrorHandlerMutex); 76#endif 77 ErrorHandler = nullptr; 78 ErrorHandlerUserData = nullptr; 79} 80 81void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) { 82 report_fatal_error(Twine(Reason), GenCrashDiag); 83} 84 85void llvm::report_fatal_error(const std::string &Reason, bool GenCrashDiag) { 86 report_fatal_error(Twine(Reason), GenCrashDiag); 87} 88 89void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) { 90 report_fatal_error(Twine(Reason), GenCrashDiag); 91} 92 93void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) { 94 llvm::fatal_error_handler_t handler = nullptr; 95 void* handlerData = nullptr; 96 { 97 // Only acquire the mutex while reading the handler, so as not to invoke a 98 // user-supplied callback under a lock. 99#if LLVM_ENABLE_THREADS == 1 100 std::lock_guard<std::mutex> Lock(ErrorHandlerMutex); 101#endif 102 handler = ErrorHandler; 103 handlerData = ErrorHandlerUserData; 104 } 105 106 if (handler) { 107 handler(handlerData, Reason.str(), GenCrashDiag); 108 } else { 109 // Blast the result out to stderr. We don't try hard to make sure this 110 // succeeds (e.g. handling EINTR) and we can't use errs() here because 111 // raw ostreams can call report_fatal_error. 112 SmallVector<char, 64> Buffer; 113 raw_svector_ostream OS(Buffer); 114 OS << "LLVM ERROR: " << Reason << "\n"; 115 StringRef MessageStr = OS.str(); 116 ssize_t written = ::write(2, MessageStr.data(), MessageStr.size()); 117 (void)written; // If something went wrong, we deliberately just give up. 118 } 119 120 // If we reached here, we are failing ungracefully. Run the interrupt handlers 121 // to make sure any special cleanups get done, in particular that we remove 122 // files registered with RemoveFileOnSignal. 123 sys::RunInterruptHandlers(); 124 125 exit(1); 126} 127 128void llvm::install_bad_alloc_error_handler(fatal_error_handler_t handler, 129 void *user_data) { 130#if LLVM_ENABLE_THREADS == 1 131 std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex); 132#endif 133 assert(!ErrorHandler && "Bad alloc error handler already registered!\n"); 134 BadAllocErrorHandler = handler; 135 BadAllocErrorHandlerUserData = user_data; 136} 137 138void llvm::remove_bad_alloc_error_handler() { 139#if LLVM_ENABLE_THREADS == 1 140 std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex); 141#endif 142 BadAllocErrorHandler = nullptr; 143 BadAllocErrorHandlerUserData = nullptr; 144} 145 146void llvm::report_bad_alloc_error(const char *Reason, bool GenCrashDiag) { 147 fatal_error_handler_t Handler = nullptr; 148 void *HandlerData = nullptr; 149 { 150 // Only acquire the mutex while reading the handler, so as not to invoke a 151 // user-supplied callback under a lock. 152#if LLVM_ENABLE_THREADS == 1 153 std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex); 154#endif 155 Handler = BadAllocErrorHandler; 156 HandlerData = BadAllocErrorHandlerUserData; 157 } 158 159 if (Handler) { 160 Handler(HandlerData, Reason, GenCrashDiag); 161 llvm_unreachable("bad alloc handler should not return"); 162 } 163 164#ifdef LLVM_ENABLE_EXCEPTIONS 165 // If exceptions are enabled, make OOM in malloc look like OOM in new. 166 throw std::bad_alloc(); 167#else 168 // Don't call the normal error handler. It may allocate memory. Directly write 169 // an OOM to stderr and abort. 170 char OOMMessage[] = "LLVM ERROR: out of memory\n"; 171 ssize_t written = ::write(2, OOMMessage, strlen(OOMMessage)); 172 (void)written; 173 abort(); 174#endif 175} 176 177#ifdef LLVM_ENABLE_EXCEPTIONS 178// Do not set custom new handler if exceptions are enabled. In this case OOM 179// errors are handled by throwing 'std::bad_alloc'. 180void llvm::install_out_of_memory_new_handler() { 181} 182#else 183// Causes crash on allocation failure. It is called prior to the handler set by 184// 'install_bad_alloc_error_handler'. 185static void out_of_memory_new_handler() { 186 llvm::report_bad_alloc_error("Allocation failed"); 187} 188 189// Installs new handler that causes crash on allocation failure. It is called by 190// InitLLVM. 191void llvm::install_out_of_memory_new_handler() { 192 std::new_handler old = std::set_new_handler(out_of_memory_new_handler); 193 (void)old; 194 assert(old == nullptr && "new-handler already installed"); 195} 196#endif 197 198void llvm::llvm_unreachable_internal(const char *msg, const char *file, 199 unsigned line) { 200 // This code intentionally doesn't call the ErrorHandler callback, because 201 // llvm_unreachable is intended to be used to indicate "impossible" 202 // situations, and not legitimate runtime errors. 203 if (msg) 204 dbgs() << msg << "\n"; 205 dbgs() << "UNREACHABLE executed"; 206 if (file) 207 dbgs() << " at " << file << ":" << line; 208 dbgs() << "!\n"; 209 abort(); 210#ifdef LLVM_BUILTIN_UNREACHABLE 211 // Windows systems and possibly others don't declare abort() to be noreturn, 212 // so use the unreachable builtin to avoid a Clang self-host warning. 213 LLVM_BUILTIN_UNREACHABLE; 214#endif 215} 216 217static void bindingsErrorHandler(void *user_data, const std::string& reason, 218 bool gen_crash_diag) { 219 LLVMFatalErrorHandler handler = 220 LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data); 221 handler(reason.c_str()); 222} 223 224void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) { 225 install_fatal_error_handler(bindingsErrorHandler, 226 LLVM_EXTENSION reinterpret_cast<void *>(Handler)); 227} 228 229void LLVMResetFatalErrorHandler() { 230 remove_fatal_error_handler(); 231} 232 233#ifdef _WIN32 234 235#include <winerror.h> 236 237// I'd rather not double the line count of the following. 238#define MAP_ERR_TO_COND(x, y) \ 239 case x: \ 240 return make_error_code(errc::y) 241 242std::error_code llvm::mapWindowsError(unsigned EV) { 243 switch (EV) { 244 MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied); 245 MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists); 246 MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device); 247 MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long); 248 MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy); 249 MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy); 250 MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied); 251 MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error); 252 MAP_ERR_TO_COND(ERROR_CANTREAD, io_error); 253 MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error); 254 MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied); 255 MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device); 256 MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy); 257 MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty); 258 MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument); 259 MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device); 260 MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists); 261 MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory); 262 MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device); 263 MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied); 264 MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device); 265 MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported); 266 MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument); 267 MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument); 268 MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available); 269 MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available); 270 MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument); 271 MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied); 272 MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory); 273 MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again); 274 MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error); 275 MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy); 276 MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory); 277 MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory); 278 MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory); 279 MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error); 280 MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again); 281 MAP_ERR_TO_COND(ERROR_SEEK, io_error); 282 MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied); 283 MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open); 284 MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error); 285 MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied); 286 MAP_ERR_TO_COND(WSAEACCES, permission_denied); 287 MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor); 288 MAP_ERR_TO_COND(WSAEFAULT, bad_address); 289 MAP_ERR_TO_COND(WSAEINTR, interrupted); 290 MAP_ERR_TO_COND(WSAEINVAL, invalid_argument); 291 MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open); 292 MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long); 293 default: 294 return std::error_code(EV, std::system_category()); 295 } 296} 297 298#endif 299