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(StringRef Reason, bool GenCrashDiag) { 87 report_fatal_error(Twine(Reason), GenCrashDiag); 88 } 89 90 void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) { 91 llvm::fatal_error_handler_t handler = nullptr; 92 void* handlerData = nullptr; 93 { 94 // Only acquire the mutex while reading the handler, so as not to invoke a 95 // user-supplied callback under a lock. 96 #if LLVM_ENABLE_THREADS == 1 97 std::lock_guard<std::mutex> Lock(ErrorHandlerMutex); 98 #endif 99 handler = ErrorHandler; 100 handlerData = ErrorHandlerUserData; 101 } 102 103 if (handler) { 104 handler(handlerData, Reason.str().c_str(), GenCrashDiag); 105 } else { 106 // Blast the result out to stderr. We don't try hard to make sure this 107 // succeeds (e.g. handling EINTR) and we can't use errs() here because 108 // raw ostreams can call report_fatal_error. 109 SmallVector<char, 64> Buffer; 110 raw_svector_ostream OS(Buffer); 111 OS << "LLVM ERROR: " << Reason << "\n"; 112 StringRef MessageStr = OS.str(); 113 ssize_t written = ::write(2, MessageStr.data(), MessageStr.size()); 114 (void)written; // If something went wrong, we deliberately just give up. 115 } 116 117 // If we reached here, we are failing ungracefully. Run the interrupt handlers 118 // to make sure any special cleanups get done, in particular that we remove 119 // files registered with RemoveFileOnSignal. 120 sys::RunInterruptHandlers(); 121 122 if (GenCrashDiag) 123 abort(); 124 else 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 const char *OOMMessage = "LLVM ERROR: out of memory\n"; 171 const char *Newline = "\n"; 172 (void)!::write(2, OOMMessage, strlen(OOMMessage)); 173 (void)!::write(2, Reason, strlen(Reason)); 174 (void)!::write(2, Newline, strlen(Newline)); 175 abort(); 176 #endif 177 } 178 179 #ifdef LLVM_ENABLE_EXCEPTIONS 180 // Do not set custom new handler if exceptions are enabled. In this case OOM 181 // errors are handled by throwing 'std::bad_alloc'. 182 void llvm::install_out_of_memory_new_handler() { 183 } 184 #else 185 // Causes crash on allocation failure. It is called prior to the handler set by 186 // 'install_bad_alloc_error_handler'. 187 static void out_of_memory_new_handler() { 188 llvm::report_bad_alloc_error("Allocation failed"); 189 } 190 191 // Installs new handler that causes crash on allocation failure. It is called by 192 // InitLLVM. 193 void llvm::install_out_of_memory_new_handler() { 194 std::new_handler old = std::set_new_handler(out_of_memory_new_handler); 195 (void)old; 196 assert((old == nullptr || old == out_of_memory_new_handler) && 197 "new-handler already installed"); 198 } 199 #endif 200 201 void llvm::llvm_unreachable_internal(const char *msg, const char *file, 202 unsigned line) { 203 // This code intentionally doesn't call the ErrorHandler callback, because 204 // llvm_unreachable is intended to be used to indicate "impossible" 205 // situations, and not legitimate runtime errors. 206 if (msg) 207 dbgs() << msg << "\n"; 208 dbgs() << "UNREACHABLE executed"; 209 if (file) 210 dbgs() << " at " << file << ":" << line; 211 dbgs() << "!\n"; 212 abort(); 213 #ifdef LLVM_BUILTIN_UNREACHABLE 214 // Windows systems and possibly others don't declare abort() to be noreturn, 215 // so use the unreachable builtin to avoid a Clang self-host warning. 216 LLVM_BUILTIN_UNREACHABLE; 217 #endif 218 } 219 220 static void bindingsErrorHandler(void *user_data, const char *reason, 221 bool gen_crash_diag) { 222 LLVMFatalErrorHandler handler = 223 LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data); 224 handler(reason); 225 } 226 227 void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) { 228 install_fatal_error_handler(bindingsErrorHandler, 229 LLVM_EXTENSION reinterpret_cast<void *>(Handler)); 230 } 231 232 void LLVMResetFatalErrorHandler() { 233 remove_fatal_error_handler(); 234 } 235 236 #ifdef _WIN32 237 238 #include <winerror.h> 239 240 // I'd rather not double the line count of the following. 241 #define MAP_ERR_TO_COND(x, y) \ 242 case x: \ 243 return make_error_code(errc::y) 244 245 std::error_code llvm::mapWindowsError(unsigned EV) { 246 switch (EV) { 247 MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied); 248 MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists); 249 MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory); 250 MAP_ERR_TO_COND(ERROR_BAD_PATHNAME, no_such_file_or_directory); 251 MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device); 252 MAP_ERR_TO_COND(ERROR_BROKEN_PIPE, broken_pipe); 253 MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long); 254 MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy); 255 MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy); 256 MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied); 257 MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error); 258 MAP_ERR_TO_COND(ERROR_CANTREAD, io_error); 259 MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error); 260 MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied); 261 MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device); 262 MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy); 263 MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty); 264 MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument); 265 MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device); 266 MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists); 267 MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory); 268 MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device); 269 MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied); 270 MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device); 271 MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported); 272 MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument); 273 MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument); 274 MAP_ERR_TO_COND(ERROR_INVALID_PARAMETER, invalid_argument); 275 MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available); 276 MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available); 277 MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument); 278 MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied); 279 MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory); 280 MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again); 281 MAP_ERR_TO_COND(ERROR_NOT_SUPPORTED, not_supported); 282 MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error); 283 MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy); 284 MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory); 285 MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory); 286 MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error); 287 MAP_ERR_TO_COND(ERROR_REPARSE_TAG_INVALID, invalid_argument); 288 MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again); 289 MAP_ERR_TO_COND(ERROR_SEEK, io_error); 290 MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied); 291 MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open); 292 MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error); 293 MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied); 294 MAP_ERR_TO_COND(WSAEACCES, permission_denied); 295 MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor); 296 MAP_ERR_TO_COND(WSAEFAULT, bad_address); 297 MAP_ERR_TO_COND(WSAEINTR, interrupted); 298 MAP_ERR_TO_COND(WSAEINVAL, invalid_argument); 299 MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open); 300 MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long); 301 default: 302 return std::error_code(EV, std::system_category()); 303 } 304 } 305 306 #endif 307