LLVM  8.0.0svn
ErrorHandling.cpp
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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 
16 #include "llvm-c/ErrorHandling.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/Error.h"
23 #include "llvm/Support/Signals.h"
24 #include "llvm/Support/Threading.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 
43 static void *ErrorHandlerUserData = nullptr;
44 
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 
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 
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(const std::string &Reason, bool GenCrashDiag) {
87  report_fatal_error(Twine(Reason), GenCrashDiag);
88 }
89 
90 void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) {
91  report_fatal_error(Twine(Reason), GenCrashDiag);
92 }
93 
94 void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
95  llvm::fatal_error_handler_t handler = nullptr;
96  void* handlerData = nullptr;
97  {
98  // Only acquire the mutex while reading the handler, so as not to invoke a
99  // user-supplied callback under a lock.
100 #if LLVM_ENABLE_THREADS == 1
101  std::lock_guard<std::mutex> Lock(ErrorHandlerMutex);
102 #endif
103  handler = ErrorHandler;
104  handlerData = ErrorHandlerUserData;
105  }
106 
107  if (handler) {
108  handler(handlerData, Reason.str(), GenCrashDiag);
109  } else {
110  // Blast the result out to stderr. We don't try hard to make sure this
111  // succeeds (e.g. handling EINTR) and we can't use errs() here because
112  // raw ostreams can call report_fatal_error.
113  SmallVector<char, 64> Buffer;
114  raw_svector_ostream OS(Buffer);
115  OS << "LLVM ERROR: " << Reason << "\n";
116  StringRef MessageStr = OS.str();
117  ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
118  (void)written; // If something went wrong, we deliberately just give up.
119  }
120 
121  // If we reached here, we are failing ungracefully. Run the interrupt handlers
122  // to make sure any special cleanups get done, in particular that we remove
123  // files registered with RemoveFileOnSignal.
125 
126  exit(1);
127 }
128 
130  void *user_data) {
131 #if LLVM_ENABLE_THREADS == 1
132  std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);
133 #endif
134  assert(!ErrorHandler && "Bad alloc error handler already registered!\n");
135  BadAllocErrorHandler = handler;
136  BadAllocErrorHandlerUserData = user_data;
137 }
138 
140 #if LLVM_ENABLE_THREADS == 1
141  std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);
142 #endif
143  BadAllocErrorHandler = nullptr;
145 }
146 
147 void llvm::report_bad_alloc_error(const char *Reason, bool GenCrashDiag) {
148  fatal_error_handler_t Handler = nullptr;
149  void *HandlerData = nullptr;
150  {
151  // Only acquire the mutex while reading the handler, so as not to invoke a
152  // user-supplied callback under a lock.
153 #if LLVM_ENABLE_THREADS == 1
154  std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);
155 #endif
156  Handler = BadAllocErrorHandler;
157  HandlerData = BadAllocErrorHandlerUserData;
158  }
159 
160  if (Handler) {
161  Handler(HandlerData, Reason, GenCrashDiag);
162  llvm_unreachable("bad alloc handler should not return");
163  }
164 
165 #ifdef LLVM_ENABLE_EXCEPTIONS
166  // If exceptions are enabled, make OOM in malloc look like OOM in new.
167  throw std::bad_alloc();
168 #else
169  // Don't call the normal error handler. It may allocate memory. Directly write
170  // an OOM to stderr and abort.
171  char OOMMessage[] = "LLVM ERROR: out of memory\n";
172  ssize_t written = ::write(2, OOMMessage, strlen(OOMMessage));
173  (void)written;
174  abort();
175 #endif
176 }
177 
178 #ifdef LLVM_ENABLE_EXCEPTIONS
179 // Do not set custom new handler if exceptions are enabled. In this case OOM
180 // errors are handled by throwing 'std::bad_alloc'.
182 }
183 #else
184 // Causes crash on allocation failure. It is called prior to the handler set by
185 // 'install_bad_alloc_error_handler'.
187  llvm::report_bad_alloc_error("Allocation failed");
188 }
189 
190 // Installs new handler that causes crash on allocation failure. It does not
191 // need to be called explicitly, if this file is linked to application, because
192 // in this case it is called during construction of 'new_handler_installer'.
194  static bool out_of_memory_new_handler_installed = false;
195  if (!out_of_memory_new_handler_installed) {
196  std::set_new_handler(out_of_memory_new_handler);
197  out_of_memory_new_handler_installed = true;
198  }
199 }
200 
201 // Static object that causes installation of 'out_of_memory_new_handler' before
202 // execution of 'main'.
203 static class NewHandlerInstaller {
204 public:
207  }
209 #endif
210 
211 void llvm::llvm_unreachable_internal(const char *msg, const char *file,
212  unsigned line) {
213  // This code intentionally doesn't call the ErrorHandler callback, because
214  // llvm_unreachable is intended to be used to indicate "impossible"
215  // situations, and not legitimate runtime errors.
216  if (msg)
217  dbgs() << msg << "\n";
218  dbgs() << "UNREACHABLE executed";
219  if (file)
220  dbgs() << " at " << file << ":" << line;
221  dbgs() << "!\n";
222  abort();
223 #ifdef LLVM_BUILTIN_UNREACHABLE
224  // Windows systems and possibly others don't declare abort() to be noreturn,
225  // so use the unreachable builtin to avoid a Clang self-host warning.
226  LLVM_BUILTIN_UNREACHABLE;
227 #endif
228 }
229 
230 static void bindingsErrorHandler(void *user_data, const std::string& reason,
231  bool gen_crash_diag) {
232  LLVMFatalErrorHandler handler =
233  LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data);
234  handler(reason.c_str());
235 }
236 
239  LLVM_EXTENSION reinterpret_cast<void *>(Handler));
240 }
241 
244 }
245 
246 #ifdef _WIN32
247 
248 #include <winerror.h>
249 
250 // I'd rather not double the line count of the following.
251 #define MAP_ERR_TO_COND(x, y) \
252  case x: \
253  return make_error_code(errc::y)
254 
255 std::error_code llvm::mapWindowsError(unsigned EV) {
256  switch (EV) {
257  MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied);
258  MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists);
259  MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device);
260  MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long);
261  MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy);
262  MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy);
263  MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied);
264  MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error);
265  MAP_ERR_TO_COND(ERROR_CANTREAD, io_error);
266  MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error);
267  MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied);
268  MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device);
269  MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy);
270  MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty);
271  MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument);
272  MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device);
273  MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);
274  MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);
275  MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);
276  MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);
277  MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);
278  MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);
279  MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument);
280  MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument);
281  MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available);
282  MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available);
283  MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument);
284  MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied);
285  MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory);
286  MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again);
287  MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error);
288  MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy);
289  MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory);
290  MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory);
291  MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory);
292  MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error);
293  MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again);
294  MAP_ERR_TO_COND(ERROR_SEEK, io_error);
295  MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied);
296  MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);
297  MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error);
298  MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied);
299  MAP_ERR_TO_COND(WSAEACCES, permission_denied);
300  MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor);
301  MAP_ERR_TO_COND(WSAEFAULT, bad_address);
302  MAP_ERR_TO_COND(WSAEINTR, interrupted);
303  MAP_ERR_TO_COND(WSAEINVAL, invalid_argument);
304  MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open);
305  MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long);
306  default:
307  return std::error_code(EV, std::system_category());
308  }
309 }
310 
311 #endif
void(* LLVMFatalErrorHandler)(const char *Reason)
Definition: ErrorHandling.h:21
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LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:139
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Definition: AllocatorList.h:24
static void bindingsErrorHandler(void *user_data, const std::string &reason, bool gen_crash_diag)
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t size() const
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Definition: StringRef.h:138
static sys::Mutex Lock
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:510
void install_bad_alloc_error_handler(fatal_error_handler_t handler, void *user_data=nullptr)
Installs a new bad alloc error handler that should be used whenever a bad alloc error, e.g.
static class NewHandlerInstaller new_handler_installer
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:128
static void * ErrorHandlerUserData
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
static fatal_error_handler_t ErrorHandler
void remove_fatal_error_handler()
Restores default error handling behaviour.
void(* fatal_error_handler_t)(void *user_data, const std::string &reason, bool gen_crash_diag)
An error handler callback.
Definition: ErrorHandling.h:26
void remove_bad_alloc_error_handler()
Restores default bad alloc error handling behavior.
static void * BadAllocErrorHandlerUserData
#define LLVM_EXTENSION
LLVM_EXTENSION - Support compilers where we have a keyword to suppress pedantic diagnostics.
Definition: Compiler.h:263
void RunInterruptHandlers()
This function runs all the registered interrupt handlers, including the removal of files registered b...
std::error_code mapWindowsError(unsigned EV)
static std::mutex BadAllocErrorHandlerMutex
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static void out_of_memory_new_handler()
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void report_bad_alloc_error(const char *Reason, bool GenCrashDiag=true)
Reports a bad alloc error, calling any user defined bad alloc error handler.
void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler)
Install a fatal error handler.
static fatal_error_handler_t BadAllocErrorHandler
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Definition: SmallVector.h:847
StringRef str()
Return a StringRef for the vector contents.
Definition: raw_ostream.h:535
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:133
LLVM_ATTRIBUTE_NORETURN void llvm_unreachable_internal(const char *msg=nullptr, const char *file=nullptr, unsigned line=0)
This function calls abort(), and prints the optional message to stderr.
void LLVMResetFatalErrorHandler()
Reset the fatal error handler.
static std::mutex ErrorHandlerMutex
std::string str() const
Return the twine contents as a std::string.
Definition: Twine.cpp:18
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Definition: StringRef.h:49
void install_out_of_memory_new_handler()
void install_fatal_error_handler(fatal_error_handler_t handler, void *user_data=nullptr)
install_fatal_error_handler - Installs a new error handler to be used whenever a serious (non-recover...