//===- lib/Support/ErrorHandling.cpp - Callbacks for errors ---------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file defines an API used to indicate fatal error conditions.  Non-fatal

// errors (most of them) should be handled through LLVMContext.

//

//===----------------------------------------------------------------------===//

#include "llvm/Support/ErrorHandling.h"

#include "llvm-c/ErrorHandling.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/Twine.h"

#include "llvm/Config/config.h"

#include "llvm/Support/Debug.h"

#include "llvm/Support/Errc.h"

#include "llvm/Support/Error.h"

#include "llvm/Support/Process.h"

#include "llvm/Support/Signals.h"

#include "llvm/Support/Threading.h"

#include "llvm/Support/WindowsError.h"

#include "llvm/Support/raw_ostream.h"

#include <cassert>

#include <cstdlib>

#include <mutex>

#include <new>

#if defined(HAVE_UNISTD_H)

# include <unistd.h>

#endif

#if defined(_MSC_VER)

# include <io.h>

# include <fcntl.h>

#endif

using namespace llvm;

static fatal_error_handler_t ErrorHandler = nullptr;

static void *ErrorHandlerUserData = nullptr;

static fatal_error_handler_t BadAllocErrorHandler = nullptr;

static void *BadAllocErrorHandlerUserData = nullptr;

#if LLVM_ENABLE_THREADS == 1

// Mutexes to synchronize installing error handlers and calling error handlers.

// Do not use ManagedStatic, or that may allocate memory while attempting to

// report an OOM.

//

// This usage of std::mutex has to be conditionalized behind ifdefs because

// of this script:

//   compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh

// That script attempts to statically link the LLVM symbolizer library with the

// STL and hide all of its symbols with 'opt -internalize'. To reduce size, it

// cuts out the threading portions of the hermetic copy of libc++ that it

// builds. We can remove these ifdefs if that script goes away.

static std::mutex ErrorHandlerMutex;

static std::mutex BadAllocErrorHandlerMutex;

#endif

void llvm::install_fatal_error_handler(fatal_error_handler_t handler,

                                       void *user_data) {

#if LLVM_ENABLE_THREADS == 1

  std::lock_guard<std::mutex> Lock(ErrorHandlerMutex);

#endif

  assert(!ErrorHandler && "Error handler already registered!\n");

  ErrorHandler = handler;

  ErrorHandlerUserData = user_data;

}

void llvm::remove_fatal_error_handler() {

#if LLVM_ENABLE_THREADS == 1

  std::lock_guard<std::mutex> Lock(ErrorHandlerMutex);

#endif

  ErrorHandler = nullptr;

  ErrorHandlerUserData = nullptr;

}

void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) {

  report_fatal_error(Twine(Reason), GenCrashDiag);

}

void llvm::report_fatal_error(const std::string &Reason, bool GenCrashDiag) {

  report_fatal_error(Twine(Reason), GenCrashDiag);

}

void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) {

  report_fatal_error(Twine(Reason), GenCrashDiag);

}

void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {

  llvm::fatal_error_handler_t handler = nullptr;

  void* handlerData = nullptr;

  {

    // Only acquire the mutex while reading the handler, so as not to invoke a

    // user-supplied callback under a lock.

#if LLVM_ENABLE_THREADS == 1

    std::lock_guard<std::mutex> Lock(ErrorHandlerMutex);

#endif

    handler = ErrorHandler;

    handlerData = ErrorHandlerUserData;

  }

  if (handler) {

    handler(handlerData, Reason.str(), GenCrashDiag);

  } else {

    // Blast the result out to stderr.  We don't try hard to make sure this

    // succeeds (e.g. handling EINTR) and we can't use errs() here because

    // raw ostreams can call report_fatal_error.

    SmallVector<char, 64> Buffer;

    raw_svector_ostream OS(Buffer);

    OS << "LLVM ERROR: " << Reason << "\n";

    StringRef MessageStr = OS.str();

    ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());

    (void)written; // If something went wrong, we deliberately just give up.

  }

  // If we reached here, we are failing ungracefully. Run the interrupt handlers

  // to make sure any special cleanups get done, in particular that we remove

  // files registered with RemoveFileOnSignal.

  sys::RunInterruptHandlers();

  abort();

}

void llvm::install_bad_alloc_error_handler(fatal_error_handler_t handler,

                                           void *user_data) {

#if LLVM_ENABLE_THREADS == 1

  std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);

#endif

  assert(!ErrorHandler && "Bad alloc error handler already registered!\n");

  BadAllocErrorHandler = handler;

  BadAllocErrorHandlerUserData = user_data;

}

void llvm::remove_bad_alloc_error_handler() {

#if LLVM_ENABLE_THREADS == 1

  std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);

#endif

  BadAllocErrorHandler = nullptr;

  BadAllocErrorHandlerUserData = nullptr;

}

void llvm::report_bad_alloc_error(const char *Reason, bool GenCrashDiag) {

  fatal_error_handler_t Handler = nullptr;

  void *HandlerData = nullptr;

  {

    // Only acquire the mutex while reading the handler, so as not to invoke a

    // user-supplied callback under a lock.

#if LLVM_ENABLE_THREADS == 1

    std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);

#endif

    Handler = BadAllocErrorHandler;

    HandlerData = BadAllocErrorHandlerUserData;

  }

  if (Handler) {

    Handler(HandlerData, Reason, GenCrashDiag);

    llvm_unreachable("bad alloc handler should not return");

  }

#ifdef LLVM_ENABLE_EXCEPTIONS

  // If exceptions are enabled, make OOM in malloc look like OOM in new.

  throw std::bad_alloc();

#else

  // Don't call the normal error handler. It may allocate memory. Directly write

  // an OOM to stderr and abort.

  char OOMMessage[] = "LLVM ERROR: out of memory\n";

  ssize_t written = ::write(2, OOMMessage, strlen(OOMMessage));

  (void)written;

  abort();

#endif

}

#ifdef LLVM_ENABLE_EXCEPTIONS

// Do not set custom new handler if exceptions are enabled. In this case OOM

// errors are handled by throwing 'std::bad_alloc'.

void llvm::install_out_of_memory_new_handler() {

}

#else

// Causes crash on allocation failure. It is called prior to the handler set by

// 'install_bad_alloc_error_handler'.

static void out_of_memory_new_handler() {

  llvm::report_bad_alloc_error("Allocation failed");

}

// Installs new handler that causes crash on allocation failure. It is called by

// InitLLVM.

void llvm::install_out_of_memory_new_handler() {

  std::new_handler old = std::set_new_handler(out_of_memory_new_handler);

  (void)old;

  assert(old == nullptr && "new-handler already installed");

}

#endif

void llvm::llvm_unreachable_internal(const char *msg, const char *file,

                                     unsigned line) {

  // This code intentionally doesn't call the ErrorHandler callback, because

  // llvm_unreachable is intended to be used to indicate "impossible"

  // situations, and not legitimate runtime errors.

  if (msg)

    dbgs() << msg << "\n";

  dbgs() << "UNREACHABLE executed";

  if (file)

    dbgs() << " at " << file << ":" << line;

  dbgs() << "!\n";

  abort();

#ifdef LLVM_BUILTIN_UNREACHABLE

  // Windows systems and possibly others don't declare abort() to be noreturn,

  // so use the unreachable builtin to avoid a Clang self-host warning.

  LLVM_BUILTIN_UNREACHABLE;

#endif

}

static void bindingsErrorHandler(void *user_data, const std::string& reason,

                                 bool gen_crash_diag) {

  LLVMFatalErrorHandler handler =

      LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data);

  handler(reason.c_str());

}

void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) {

  install_fatal_error_handler(bindingsErrorHandler,

                              LLVM_EXTENSION reinterpret_cast<void *>(Handler));

}

void LLVMResetFatalErrorHandler() {

  remove_fatal_error_handler();

}

#ifdef _WIN32

#include <winerror.h>

// I'd rather not double the line count of the following.

#define MAP_ERR_TO_COND(x, y)                                                  \

  case x:                                                                      \

    return make_error_code(errc::y)

std::error_code llvm::mapWindowsError(unsigned EV) {

  switch (EV) {

    MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied);

    MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists);

    MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device);

    MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long);

    MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy);

    MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy);

    MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied);

    MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error);

    MAP_ERR_TO_COND(ERROR_CANTREAD, io_error);

    MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error);

    MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied);

    MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device);

    MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy);

    MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty);

    MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument);

    MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device);

    MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);

    MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);

    MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);

    MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);

    MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);

    MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);

    MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument);

    MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument);

    MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available);

    MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available);

    MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument);

    MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied);

    MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory);

    MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again);

    MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error);

    MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy);

    MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory);

    MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory);

    MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory);

    MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error);

    MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again);

    MAP_ERR_TO_COND(ERROR_SEEK, io_error);

    MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied);

    MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);

    MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error);

    MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied);

    MAP_ERR_TO_COND(WSAEACCES, permission_denied);

    MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor);

    MAP_ERR_TO_COND(WSAEFAULT, bad_address);

    MAP_ERR_TO_COND(WSAEINTR, interrupted);

    MAP_ERR_TO_COND(WSAEINVAL, invalid_argument);

    MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open);

    MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long);

  default:

    return std::error_code(EV, std::system_category());

  }

}

#endif