1//===- lib/Support/ErrorHandling.cpp - Callbacks for errors ---------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines an API used to indicate fatal error conditions.  Non-fatal
11// errors (most of them) should be handled through LLVMContext.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/Support/ErrorHandling.h"
16#include "llvm-c/Core.h"
17#include "llvm/ADT/SmallVector.h"
18#include "llvm/ADT/Twine.h"
19#include "llvm/Config/config.h"
20#include "llvm/Support/Debug.h"
21#include "llvm/Support/Errc.h"
22#include "llvm/Support/ManagedStatic.h"
23#include "llvm/Support/Mutex.h"
24#include "llvm/Support/MutexGuard.h"
25#include "llvm/Support/Signals.h"
26#include "llvm/Support/Threading.h"
27#include "llvm/Support/WindowsError.h"
28#include "llvm/Support/raw_ostream.h"
29#include <cassert>
30#include <cstdlib>
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
40using namespace llvm;
41
42static fatal_error_handler_t ErrorHandler = nullptr;
43static void *ErrorHandlerUserData = nullptr;
44
45static ManagedStatic<sys::Mutex> ErrorHandlerMutex;
46
47void llvm::install_fatal_error_handler(fatal_error_handler_t handler,
48                                       void *user_data) {
49  llvm::MutexGuard Lock(*ErrorHandlerMutex);
50  assert(!ErrorHandler && "Error handler already registered!\n");
51  ErrorHandler = handler;
52  ErrorHandlerUserData = user_data;
53}
54
55void llvm::remove_fatal_error_handler() {
56  llvm::MutexGuard Lock(*ErrorHandlerMutex);
57  ErrorHandler = nullptr;
58  ErrorHandlerUserData = nullptr;
59}
60
61void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) {
62  report_fatal_error(Twine(Reason), GenCrashDiag);
63}
64
65void llvm::report_fatal_error(const std::string &Reason, bool GenCrashDiag) {
66  report_fatal_error(Twine(Reason), GenCrashDiag);
67}
68
69void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) {
70  report_fatal_error(Twine(Reason), GenCrashDiag);
71}
72
73void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
74  llvm::fatal_error_handler_t handler = nullptr;
75  void* handlerData = nullptr;
76  {
77    // Only acquire the mutex while reading the handler, so as not to invoke a
78    // user-supplied callback under a lock.
79    llvm::MutexGuard Lock(*ErrorHandlerMutex);
80    handler = ErrorHandler;
81    handlerData = ErrorHandlerUserData;
82  }
83
84  if (handler) {
85    handler(handlerData, Reason.str(), GenCrashDiag);
86  } else {
87    // Blast the result out to stderr.  We don't try hard to make sure this
88    // succeeds (e.g. handling EINTR) and we can't use errs() here because
89    // raw ostreams can call report_fatal_error.
90    SmallVector<char, 64> Buffer;
91    raw_svector_ostream OS(Buffer);
92    OS << "LLVM ERROR: " << Reason << "\n";
93    StringRef MessageStr = OS.str();
94    ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
95    (void)written; // If something went wrong, we deliberately just give up.
96  }
97
98  // If we reached here, we are failing ungracefully. Run the interrupt handlers
99  // to make sure any special cleanups get done, in particular that we remove
100  // files registered with RemoveFileOnSignal.
101  sys::RunInterruptHandlers();
102
103  exit(1);
104}
105
106void llvm::llvm_unreachable_internal(const char *msg, const char *file,
107                                     unsigned line) {
108  // This code intentionally doesn't call the ErrorHandler callback, because
109  // llvm_unreachable is intended to be used to indicate "impossible"
110  // situations, and not legitimate runtime errors.
111  if (msg)
112    dbgs() << msg << "\n";
113  dbgs() << "UNREACHABLE executed";
114  if (file)
115    dbgs() << " at " << file << ":" << line;
116  dbgs() << "!\n";
117  abort();
118#ifdef LLVM_BUILTIN_UNREACHABLE
119  // Windows systems and possibly others don't declare abort() to be noreturn,
120  // so use the unreachable builtin to avoid a Clang self-host warning.
121  LLVM_BUILTIN_UNREACHABLE;
122#endif
123}
124
125static void bindingsErrorHandler(void *user_data, const std::string& reason,
126                                 bool gen_crash_diag) {
127  LLVMFatalErrorHandler handler =
128      LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data);
129  handler(reason.c_str());
130}
131
132void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) {
133  install_fatal_error_handler(bindingsErrorHandler,
134                              LLVM_EXTENSION reinterpret_cast<void *>(Handler));
135}
136
137void LLVMResetFatalErrorHandler() {
138  remove_fatal_error_handler();
139}
140
141#ifdef LLVM_ON_WIN32
142
143#include <winerror.h>
144
145// I'd rather not double the line count of the following.
146#define MAP_ERR_TO_COND(x, y)                                                  \
147  case x:                                                                      \
148    return make_error_code(errc::y)
149
150std::error_code llvm::mapWindowsError(unsigned EV) {
151  switch (EV) {
152    MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied);
153    MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists);
154    MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device);
155    MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long);
156    MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy);
157    MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy);
158    MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied);
159    MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error);
160    MAP_ERR_TO_COND(ERROR_CANTREAD, io_error);
161    MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error);
162    MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied);
163    MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device);
164    MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy);
165    MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty);
166    MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument);
167    MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device);
168    MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);
169    MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);
170    MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);
171    MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);
172    MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);
173    MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);
174    MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument);
175    MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument);
176    MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available);
177    MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available);
178    MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument);
179    MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied);
180    MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory);
181    MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again);
182    MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error);
183    MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy);
184    MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory);
185    MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory);
186    MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory);
187    MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error);
188    MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again);
189    MAP_ERR_TO_COND(ERROR_SEEK, io_error);
190    MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied);
191    MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);
192    MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error);
193    MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied);
194    MAP_ERR_TO_COND(WSAEACCES, permission_denied);
195    MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor);
196    MAP_ERR_TO_COND(WSAEFAULT, bad_address);
197    MAP_ERR_TO_COND(WSAEINTR, interrupted);
198    MAP_ERR_TO_COND(WSAEINVAL, invalid_argument);
199    MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open);
200    MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long);
201  default:
202    return std::error_code(EV, std::system_category());
203  }
204}
205
206#endif
207