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