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/Process.h" 23 #include "llvm/Support/Signals.h" 24 #include "llvm/Support/Threading.h" 25 #include "llvm/Support/WindowsError.h" 26 #include "llvm/Support/raw_ostream.h" 27 #include <cassert> 28 #include <cstdlib> 29 #include <mutex> 30 #include <new> 31 32 #if defined(HAVE_UNISTD_H) 33 # include <unistd.h> 34 #endif 35 #if defined(_MSC_VER) 36 # include <io.h> 37 # include <fcntl.h> 38 #endif 39 40 using namespace llvm; 41 42 static fatal_error_handler_t ErrorHandler = nullptr; 43 static void *ErrorHandlerUserData = nullptr; 44 45 static fatal_error_handler_t BadAllocErrorHandler = nullptr; 46 static void *BadAllocErrorHandlerUserData = nullptr; 47 48 #if LLVM_ENABLE_THREADS == 1 49 // Mutexes to synchronize installing error handlers and calling error handlers. 50 // Do not use ManagedStatic, or that may allocate memory while attempting to 51 // report an OOM. 52 // 53 // This usage of std::mutex has to be conditionalized behind ifdefs because 54 // of this script: 55 // compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh 56 // That script attempts to statically link the LLVM symbolizer library with the 57 // STL and hide all of its symbols with 'opt -internalize'. To reduce size, it 58 // cuts out the threading portions of the hermetic copy of libc++ that it 59 // builds. We can remove these ifdefs if that script goes away. 60 static std::mutex ErrorHandlerMutex; 61 static std::mutex BadAllocErrorHandlerMutex; 62 #endif 63 64 void llvm::install_fatal_error_handler(fatal_error_handler_t handler, 65 void *user_data) { 66 #if LLVM_ENABLE_THREADS == 1 67 std::lock_guard<std::mutex> Lock(ErrorHandlerMutex); 68 #endif 69 assert(!ErrorHandler && "Error handler already registered!\n"); 70 ErrorHandler = handler; 71 ErrorHandlerUserData = user_data; 72 } 73 74 void llvm::remove_fatal_error_handler() { 75 #if LLVM_ENABLE_THREADS == 1 76 std::lock_guard<std::mutex> Lock(ErrorHandlerMutex); 77 #endif 78 ErrorHandler = nullptr; 79 ErrorHandlerUserData = nullptr; 80 } 81 82 void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) { 83 report_fatal_error(Twine(Reason), GenCrashDiag); 84 } 85 86 void llvm::report_fatal_error(const std::string &Reason, bool GenCrashDiag) { 87 report_fatal_error(Twine(Reason), GenCrashDiag); 88 } 89 90 void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) { 91 report_fatal_error(Twine(Reason), GenCrashDiag); 92 } 93 94 void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) { 95 llvm::fatal_error_handler_t handler = nullptr; 96 void* handlerData = nullptr; 97 { 98 // Only acquire the mutex while reading the handler, so as not to invoke a 99 // user-supplied callback under a lock. 100 #if LLVM_ENABLE_THREADS == 1 101 std::lock_guard<std::mutex> Lock(ErrorHandlerMutex); 102 #endif 103 handler = ErrorHandler; 104 handlerData = ErrorHandlerUserData; 105 } 106 107 if (handler) { 108 handler(handlerData, Reason.str(), GenCrashDiag); 109 } else { 110 // Blast the result out to stderr. We don't try hard to make sure this 111 // succeeds (e.g. handling EINTR) and we can't use errs() here because 112 // raw ostreams can call report_fatal_error. 113 SmallVector<char, 64> Buffer; 114 raw_svector_ostream OS(Buffer); 115 OS << "LLVM ERROR: " << Reason << "\n"; 116 StringRef MessageStr = OS.str(); 117 ssize_t written = ::write(2, MessageStr.data(), MessageStr.size()); 118 (void)written; // If something went wrong, we deliberately just give up. 119 } 120 121 // If we reached here, we are failing ungracefully. Run the interrupt handlers 122 // to make sure any special cleanups get done, in particular that we remove 123 // files registered with RemoveFileOnSignal. 124 sys::RunInterruptHandlers(); 125 126 abort(); 127 } 128 129 void llvm::install_bad_alloc_error_handler(fatal_error_handler_t handler, 130 void *user_data) { 131 #if LLVM_ENABLE_THREADS == 1 132 std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex); 133 #endif 134 assert(!ErrorHandler && "Bad alloc error handler already registered!\n"); 135 BadAllocErrorHandler = handler; 136 BadAllocErrorHandlerUserData = user_data; 137 } 138 139 void llvm::remove_bad_alloc_error_handler() { 140 #if LLVM_ENABLE_THREADS == 1 141 std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex); 142 #endif 143 BadAllocErrorHandler = nullptr; 144 BadAllocErrorHandlerUserData = nullptr; 145 } 146 147 void llvm::report_bad_alloc_error(const char *Reason, bool GenCrashDiag) { 148 fatal_error_handler_t Handler = nullptr; 149 void *HandlerData = nullptr; 150 { 151 // Only acquire the mutex while reading the handler, so as not to invoke a 152 // user-supplied callback under a lock. 153 #if LLVM_ENABLE_THREADS == 1 154 std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex); 155 #endif 156 Handler = BadAllocErrorHandler; 157 HandlerData = BadAllocErrorHandlerUserData; 158 } 159 160 if (Handler) { 161 Handler(HandlerData, Reason, GenCrashDiag); 162 llvm_unreachable("bad alloc handler should not return"); 163 } 164 165 #ifdef LLVM_ENABLE_EXCEPTIONS 166 // If exceptions are enabled, make OOM in malloc look like OOM in new. 167 throw std::bad_alloc(); 168 #else 169 // Don't call the normal error handler. It may allocate memory. Directly write 170 // an OOM to stderr and abort. 171 char OOMMessage[] = "LLVM ERROR: out of memory\n"; 172 ssize_t written = ::write(2, OOMMessage, strlen(OOMMessage)); 173 (void)written; 174 abort(); 175 #endif 176 } 177 178 #ifdef LLVM_ENABLE_EXCEPTIONS 179 // Do not set custom new handler if exceptions are enabled. In this case OOM 180 // errors are handled by throwing 'std::bad_alloc'. 181 void llvm::install_out_of_memory_new_handler() { 182 } 183 #else 184 // Causes crash on allocation failure. It is called prior to the handler set by 185 // 'install_bad_alloc_error_handler'. 186 static void out_of_memory_new_handler() { 187 llvm::report_bad_alloc_error("Allocation failed"); 188 } 189 190 // Installs new handler that causes crash on allocation failure. It is called by 191 // InitLLVM. 192 void llvm::install_out_of_memory_new_handler() { 193 std::new_handler old = std::set_new_handler(out_of_memory_new_handler); 194 (void)old; 195 assert(old == nullptr && "new-handler already installed"); 196 } 197 #endif 198 199 void llvm::llvm_unreachable_internal(const char *msg, const char *file, 200 unsigned line) { 201 // This code intentionally doesn't call the ErrorHandler callback, because 202 // llvm_unreachable is intended to be used to indicate "impossible" 203 // situations, and not legitimate runtime errors. 204 if (msg) 205 dbgs() << msg << "\n"; 206 dbgs() << "UNREACHABLE executed"; 207 if (file) 208 dbgs() << " at " << file << ":" << line; 209 dbgs() << "!\n"; 210 abort(); 211 #ifdef LLVM_BUILTIN_UNREACHABLE 212 // Windows systems and possibly others don't declare abort() to be noreturn, 213 // so use the unreachable builtin to avoid a Clang self-host warning. 214 LLVM_BUILTIN_UNREACHABLE; 215 #endif 216 } 217 218 static void bindingsErrorHandler(void *user_data, const std::string& reason, 219 bool gen_crash_diag) { 220 LLVMFatalErrorHandler handler = 221 LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data); 222 handler(reason.c_str()); 223 } 224 225 void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) { 226 install_fatal_error_handler(bindingsErrorHandler, 227 LLVM_EXTENSION reinterpret_cast<void *>(Handler)); 228 } 229 230 void LLVMResetFatalErrorHandler() { 231 remove_fatal_error_handler(); 232 } 233 234 #ifdef _WIN32 235 236 #include <winerror.h> 237 238 // I'd rather not double the line count of the following. 239 #define MAP_ERR_TO_COND(x, y) \ 240 case x: \ 241 return make_error_code(errc::y) 242 243 std::error_code llvm::mapWindowsError(unsigned EV) { 244 switch (EV) { 245 MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied); 246 MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists); 247 MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device); 248 MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long); 249 MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy); 250 MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy); 251 MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied); 252 MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error); 253 MAP_ERR_TO_COND(ERROR_CANTREAD, io_error); 254 MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error); 255 MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied); 256 MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device); 257 MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy); 258 MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty); 259 MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument); 260 MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device); 261 MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists); 262 MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory); 263 MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device); 264 MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied); 265 MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device); 266 MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported); 267 MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument); 268 MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument); 269 MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available); 270 MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available); 271 MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument); 272 MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied); 273 MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory); 274 MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again); 275 MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error); 276 MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy); 277 MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory); 278 MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory); 279 MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory); 280 MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error); 281 MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again); 282 MAP_ERR_TO_COND(ERROR_SEEK, io_error); 283 MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied); 284 MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open); 285 MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error); 286 MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied); 287 MAP_ERR_TO_COND(WSAEACCES, permission_denied); 288 MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor); 289 MAP_ERR_TO_COND(WSAEFAULT, bad_address); 290 MAP_ERR_TO_COND(WSAEINTR, interrupted); 291 MAP_ERR_TO_COND(WSAEINVAL, invalid_argument); 292 MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open); 293 MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long); 294 default: 295 return std::error_code(EV, std::system_category()); 296 } 297 } 298 299 #endif 300