llvm/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/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