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 39 using namespace llvm; 40 41 static fatal_error_handler_t ErrorHandler = nullptr; 42 static void *ErrorHandlerUserData = nullptr; 43 44 static fatal_error_handler_t BadAllocErrorHandler = nullptr; 45 static 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. 59 static std::mutex ErrorHandlerMutex; 60 static std::mutex BadAllocErrorHandlerMutex; 61 #endif 62 63 void 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 73 void 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 81 void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) { 82 report_fatal_error(Twine(Reason), GenCrashDiag); 83 } 84 85 void llvm::report_fatal_error(const std::string &Reason, bool GenCrashDiag) { 86 report_fatal_error(Twine(Reason), GenCrashDiag); 87 } 88 89 void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) { 90 report_fatal_error(Twine(Reason), GenCrashDiag); 91 } 92 93 void 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 } 127 128 void 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 } 137 138 void 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 } 145 146 void 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'. 180 void 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'. 185 static 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 does not 190 // need to be called explicitly, if this file is linked to application, because 191 // in this case it is called during construction of 'new_handler_installer'. 192 void llvm::install_out_of_memory_new_handler() { 193 static bool out_of_memory_new_handler_installed = false; 194 if (!out_of_memory_new_handler_installed) { 195 std::set_new_handler(out_of_memory_new_handler); 196 out_of_memory_new_handler_installed = true; 197 } 198 } 199 200 // Static object that causes installation of 'out_of_memory_new_handler' before 201 // execution of 'main'. 202 static class NewHandlerInstaller { 203 public: 204 NewHandlerInstaller() { 205 install_out_of_memory_new_handler(); 206 } 207 } new_handler_installer; 208 #endif 209 210 void llvm::llvm_unreachable_internal(const char *msg, const char *file, 211 unsigned line) { 212 // This code intentionally doesn't call the ErrorHandler callback, because 213 // llvm_unreachable is intended to be used to indicate "impossible" 214 // situations, and not legitimate runtime errors. 215 if (msg) 216 dbgs() << msg << "\n"; 217 dbgs() << "UNREACHABLE executed"; 218 if (file) 219 dbgs() << " at " << file << ":" << line; 220 dbgs() << "!\n"; 221 abort(); 222 #ifdef LLVM_BUILTIN_UNREACHABLE 223 // Windows systems and possibly others don't declare abort() to be noreturn, 224 // so use the unreachable builtin to avoid a Clang self-host warning. 225 LLVM_BUILTIN_UNREACHABLE; 226 #endif 227 } 228 229 static void bindingsErrorHandler(void *user_data, const std::string& reason, 230 bool gen_crash_diag) { 231 LLVMFatalErrorHandler handler = 232 LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data); 233 handler(reason.c_str()); 234 } 235 236 void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) { 237 install_fatal_error_handler(bindingsErrorHandler, 238 LLVM_EXTENSION reinterpret_cast<void *>(Handler)); 239 } 240 241 void LLVMResetFatalErrorHandler() { 242 remove_fatal_error_handler(); 243 } 244 245 #ifdef _WIN32 246 247 #include <winerror.h> 248 249 // I'd rather not double the line count of the following. 250 #define MAP_ERR_TO_COND(x, y) \ 251 case x: \ 252 return make_error_code(errc::y) 253 254 std::error_code llvm::mapWindowsError(unsigned EV) { 255 switch (EV) { 256 MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied); 257 MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists); 258 MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device); 259 MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long); 260 MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy); 261 MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy); 262 MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied); 263 MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error); 264 MAP_ERR_TO_COND(ERROR_CANTREAD, io_error); 265 MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error); 266 MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied); 267 MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device); 268 MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy); 269 MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty); 270 MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument); 271 MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device); 272 MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists); 273 MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory); 274 MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device); 275 MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied); 276 MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device); 277 MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported); 278 MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument); 279 MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument); 280 MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available); 281 MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available); 282 MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument); 283 MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied); 284 MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory); 285 MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again); 286 MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error); 287 MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy); 288 MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory); 289 MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory); 290 MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory); 291 MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error); 292 MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again); 293 MAP_ERR_TO_COND(ERROR_SEEK, io_error); 294 MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied); 295 MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open); 296 MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error); 297 MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied); 298 MAP_ERR_TO_COND(WSAEACCES, permission_denied); 299 MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor); 300 MAP_ERR_TO_COND(WSAEFAULT, bad_address); 301 MAP_ERR_TO_COND(WSAEINTR, interrupted); 302 MAP_ERR_TO_COND(WSAEINVAL, invalid_argument); 303 MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open); 304 MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long); 305 default: 306 return std::error_code(EV, std::system_category()); 307 } 308 } 309 310 #endif 311