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/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/ManagedStatic.h"
24 #include "llvm/Support/Mutex.h"
25 #include "llvm/Support/MutexGuard.h"
26 #include "llvm/Support/Signals.h"
27 #include "llvm/Support/Threading.h"
28 #include "llvm/Support/WindowsError.h"
29 #include "llvm/Support/raw_ostream.h"
30 #include <cassert>
31 #include <cstdlib>
32 #include <new>
33 
34 #if defined(HAVE_UNISTD_H)
35 # include <unistd.h>
36 #endif
37 #if defined(_MSC_VER)
38 # include <io.h>
39 # include <fcntl.h>
40 #endif
41 
42 using namespace llvm;
43 
44 static fatal_error_handler_t ErrorHandler = nullptr;
45 static void *ErrorHandlerUserData = nullptr;
46 static ManagedStatic<sys::Mutex> ErrorHandlerMutex;
47 
48 static fatal_error_handler_t BadAllocErrorHandler = nullptr;
49 static void *BadAllocErrorHandlerUserData = nullptr;
50 static ManagedStatic<sys::Mutex> BadAllocErrorHandlerMutex;
51 
52 void llvm::install_fatal_error_handler(fatal_error_handler_t handler,
53                                        void *user_data) {
54   llvm::MutexGuard Lock(*ErrorHandlerMutex);
55   assert(!ErrorHandler && "Error handler already registered!\n");
56   ErrorHandler = handler;
57   ErrorHandlerUserData = user_data;
58 }
59 
60 void llvm::remove_fatal_error_handler() {
61   llvm::MutexGuard Lock(*ErrorHandlerMutex);
62   ErrorHandler = nullptr;
63   ErrorHandlerUserData = nullptr;
64 }
65 
66 void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) {
67   report_fatal_error(Twine(Reason), GenCrashDiag);
68 }
69 
70 void llvm::report_fatal_error(const std::string &Reason, bool GenCrashDiag) {
71   report_fatal_error(Twine(Reason), GenCrashDiag);
72 }
73 
74 void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) {
75   report_fatal_error(Twine(Reason), GenCrashDiag);
76 }
77 
78 void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
79   llvm::fatal_error_handler_t handler = nullptr;
80   void* handlerData = nullptr;
81   {
82     // Only acquire the mutex while reading the handler, so as not to invoke a
83     // user-supplied callback under a lock.
84     llvm::MutexGuard Lock(*ErrorHandlerMutex);
85     handler = ErrorHandler;
86     handlerData = ErrorHandlerUserData;
87   }
88 
89   if (handler) {
90     handler(handlerData, Reason.str(), GenCrashDiag);
91   } else {
92     // Blast the result out to stderr.  We don't try hard to make sure this
93     // succeeds (e.g. handling EINTR) and we can't use errs() here because
94     // raw ostreams can call report_fatal_error.
95     SmallVector<char, 64> Buffer;
96     raw_svector_ostream OS(Buffer);
97     OS << "LLVM ERROR: " << Reason << "\n";
98     StringRef MessageStr = OS.str();
99     ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
100     (void)written; // If something went wrong, we deliberately just give up.
101   }
102 
103   // If we reached here, we are failing ungracefully. Run the interrupt handlers
104   // to make sure any special cleanups get done, in particular that we remove
105   // files registered with RemoveFileOnSignal.
106   sys::RunInterruptHandlers();
107 
108   exit(1);
109 }
110 
111 void llvm::install_bad_alloc_error_handler(fatal_error_handler_t handler,
112                                            void *user_data) {
113   MutexGuard Lock(*BadAllocErrorHandlerMutex);
114   assert(!ErrorHandler && "Bad alloc error handler already registered!\n");
115   BadAllocErrorHandler = handler;
116   BadAllocErrorHandlerUserData = user_data;
117 }
118 
119 void llvm::remove_bad_alloc_error_handler() {
120   MutexGuard Lock(*BadAllocErrorHandlerMutex);
121   BadAllocErrorHandler = nullptr;
122   BadAllocErrorHandlerUserData = nullptr;
123 }
124 
125 void llvm::report_bad_alloc_error(const char *Reason, bool GenCrashDiag) {
126   fatal_error_handler_t Handler = nullptr;
127   void *HandlerData = nullptr;
128   {
129     // Only acquire the mutex while reading the handler, so as not to invoke a
130     // user-supplied callback under a lock.
131     MutexGuard Lock(*BadAllocErrorHandlerMutex);
132     Handler = BadAllocErrorHandler;
133     HandlerData = BadAllocErrorHandlerUserData;
134   }
135 
136   if (Handler) {
137     Handler(HandlerData, Reason, GenCrashDiag);
138     llvm_unreachable("bad alloc handler should not return");
139   }
140 
141 #ifdef LLVM_ENABLE_EXCEPTIONS
142   // If exceptions are enabled, make OOM in malloc look like OOM in new.
143   throw std::bad_alloc();
144 #else
145   // Otherwise, fall back to the normal fatal error handler.
146   report_fatal_error("out of memory: " + Twine(Reason));
147 #endif
148 }
149 
150 void llvm::llvm_unreachable_internal(const char *msg, const char *file,
151                                      unsigned line) {
152   // This code intentionally doesn't call the ErrorHandler callback, because
153   // llvm_unreachable is intended to be used to indicate "impossible"
154   // situations, and not legitimate runtime errors.
155   if (msg)
156     dbgs() << msg << "\n";
157   dbgs() << "UNREACHABLE executed";
158   if (file)
159     dbgs() << " at " << file << ":" << line;
160   dbgs() << "!\n";
161   abort();
162 #ifdef LLVM_BUILTIN_UNREACHABLE
163   // Windows systems and possibly others don't declare abort() to be noreturn,
164   // so use the unreachable builtin to avoid a Clang self-host warning.
165   LLVM_BUILTIN_UNREACHABLE;
166 #endif
167 }
168 
169 static void bindingsErrorHandler(void *user_data, const std::string& reason,
170                                  bool gen_crash_diag) {
171   LLVMFatalErrorHandler handler =
172       LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data);
173   handler(reason.c_str());
174 }
175 
176 void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) {
177   install_fatal_error_handler(bindingsErrorHandler,
178                               LLVM_EXTENSION reinterpret_cast<void *>(Handler));
179 }
180 
181 void LLVMResetFatalErrorHandler() {
182   remove_fatal_error_handler();
183 }
184 
185 #ifdef LLVM_ON_WIN32
186 
187 #include <winerror.h>
188 
189 // I'd rather not double the line count of the following.
190 #define MAP_ERR_TO_COND(x, y)                                                  \
191   case x:                                                                      \
192     return make_error_code(errc::y)
193 
194 std::error_code llvm::mapWindowsError(unsigned EV) {
195   switch (EV) {
196     MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied);
197     MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists);
198     MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device);
199     MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long);
200     MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy);
201     MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy);
202     MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied);
203     MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error);
204     MAP_ERR_TO_COND(ERROR_CANTREAD, io_error);
205     MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error);
206     MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied);
207     MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device);
208     MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy);
209     MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty);
210     MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument);
211     MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device);
212     MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);
213     MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);
214     MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);
215     MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);
216     MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);
217     MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);
218     MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument);
219     MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument);
220     MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available);
221     MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available);
222     MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument);
223     MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied);
224     MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory);
225     MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again);
226     MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error);
227     MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy);
228     MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory);
229     MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory);
230     MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory);
231     MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error);
232     MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again);
233     MAP_ERR_TO_COND(ERROR_SEEK, io_error);
234     MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied);
235     MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);
236     MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error);
237     MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied);
238     MAP_ERR_TO_COND(WSAEACCES, permission_denied);
239     MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor);
240     MAP_ERR_TO_COND(WSAEFAULT, bad_address);
241     MAP_ERR_TO_COND(WSAEINTR, interrupted);
242     MAP_ERR_TO_COND(WSAEINVAL, invalid_argument);
243     MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open);
244     MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long);
245   default:
246     return std::error_code(EV, std::system_category());
247   }
248 }
249 
250 #endif
251