lib/Support/ErrorHandling.cpp

   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