xref: /freebsd/contrib/llvm-project/llvm/lib/Support/ErrorHandling.cpp (revision dab59af3bcc7cb7ba01569d3044894b3e860ad56)
1 //===- lib/Support/ErrorHandling.cpp - Callbacks for errors ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines an API used to indicate fatal error conditions.  Non-fatal
10 // errors (most of them) should be handled through LLVMContext.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Support/ErrorHandling.h"
15 #include "llvm-c/ErrorHandling.h"
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/ADT/Twine.h"
18 #include "llvm/Config/config.h"
19 #include "llvm/Support/Debug.h"
20 #include "llvm/Support/Errc.h"
21 #include "llvm/Support/Error.h"
22 #include "llvm/Support/Process.h"
23 #include "llvm/Support/Signals.h"
24 #include "llvm/Support/Threading.h"
25 #include "llvm/Support/WindowsError.h"
26 #include "llvm/Support/raw_ostream.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 
42 static fatal_error_handler_t ErrorHandler = nullptr;
43 static void *ErrorHandlerUserData = nullptr;
44 
45 static fatal_error_handler_t BadAllocErrorHandler = nullptr;
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 
64 void llvm::install_fatal_error_handler(fatal_error_handler_t handler,
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 
74 void llvm::remove_fatal_error_handler() {
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(StringRef Reason, bool GenCrashDiag) {
87   report_fatal_error(Twine(Reason), GenCrashDiag);
88 }
89 
90 void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
91   llvm::fatal_error_handler_t handler = nullptr;
92   void* handlerData = nullptr;
93   {
94     // Only acquire the mutex while reading the handler, so as not to invoke a
95     // user-supplied callback under a lock.
96 #if LLVM_ENABLE_THREADS == 1
97     std::lock_guard<std::mutex> Lock(ErrorHandlerMutex);
98 #endif
99     handler = ErrorHandler;
100     handlerData = ErrorHandlerUserData;
101   }
102 
103   if (handler) {
104     handler(handlerData, Reason.str().c_str(), GenCrashDiag);
105   } else {
106     // Blast the result out to stderr.  We don't try hard to make sure this
107     // succeeds (e.g. handling EINTR) and we can't use errs() here because
108     // raw ostreams can call report_fatal_error.
109     SmallVector<char, 64> Buffer;
110     raw_svector_ostream OS(Buffer);
111     OS << "LLVM ERROR: " << Reason << "\n";
112     StringRef MessageStr = OS.str();
113     ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
114     (void)written; // If something went wrong, we deliberately just give up.
115   }
116 
117   // If we reached here, we are failing ungracefully. Run the interrupt handlers
118   // to make sure any special cleanups get done, in particular that we remove
119   // files registered with RemoveFileOnSignal.
120   sys::RunInterruptHandlers();
121 
122   if (GenCrashDiag)
123     abort();
124   else
125     exit(1);
126 }
127 
128 void llvm::install_bad_alloc_error_handler(fatal_error_handler_t handler,
129                                            void *user_data) {
130 #if LLVM_ENABLE_THREADS == 1
131   std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);
132 #endif
133   assert(!BadAllocErrorHandler &&
134          "Bad alloc error handler already registered!\n");
135   BadAllocErrorHandler = handler;
136   BadAllocErrorHandlerUserData = user_data;
137 }
138 
139 void llvm::remove_bad_alloc_error_handler() {
140 #if LLVM_ENABLE_THREADS == 1
141   std::lock_guard<std::mutex> Lock(BadAllocErrorHandlerMutex);
142 #endif
143   BadAllocErrorHandler = nullptr;
144   BadAllocErrorHandlerUserData = 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   const char *OOMMessage = "LLVM ERROR: out of memory\n";
172   const char *Newline = "\n";
173   (void)!::write(2, OOMMessage, strlen(OOMMessage));
174   (void)!::write(2, Reason, strlen(Reason));
175   (void)!::write(2, Newline, strlen(Newline));
176   abort();
177 #endif
178 }
179 
180 #ifdef LLVM_ENABLE_EXCEPTIONS
181 // Do not set custom new handler if exceptions are enabled. In this case OOM
182 // errors are handled by throwing 'std::bad_alloc'.
183 void llvm::install_out_of_memory_new_handler() {
184 }
185 #else
186 // Causes crash on allocation failure. It is called prior to the handler set by
187 // 'install_bad_alloc_error_handler'.
188 static void out_of_memory_new_handler() {
189   llvm::report_bad_alloc_error("Allocation failed");
190 }
191 
192 // Installs new handler that causes crash on allocation failure. It is called by
193 // InitLLVM.
194 void llvm::install_out_of_memory_new_handler() {
195   std::new_handler old = std::set_new_handler(out_of_memory_new_handler);
196   (void)old;
197   assert((old == nullptr || old == out_of_memory_new_handler) &&
198          "new-handler already installed");
199 }
200 #endif
201 
202 void llvm::llvm_unreachable_internal(const char *msg, const char *file,
203                                      unsigned line) {
204   // This code intentionally doesn't call the ErrorHandler callback, because
205   // llvm_unreachable is intended to be used to indicate "impossible"
206   // situations, and not legitimate runtime errors.
207   if (msg)
208     dbgs() << msg << "\n";
209   dbgs() << "UNREACHABLE executed";
210   if (file)
211     dbgs() << " at " << file << ":" << line;
212   dbgs() << "!\n";
213   abort();
214 #ifdef LLVM_BUILTIN_UNREACHABLE
215   // Windows systems and possibly others don't declare abort() to be noreturn,
216   // so use the unreachable builtin to avoid a Clang self-host warning.
217   LLVM_BUILTIN_UNREACHABLE;
218 #endif
219 }
220 
221 static void bindingsErrorHandler(void *user_data, const char *reason,
222                                  bool gen_crash_diag) {
223   LLVMFatalErrorHandler handler =
224       LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data);
225   handler(reason);
226 }
227 
228 void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) {
229   install_fatal_error_handler(bindingsErrorHandler,
230                               LLVM_EXTENSION reinterpret_cast<void *>(Handler));
231 }
232 
233 void LLVMResetFatalErrorHandler() {
234   remove_fatal_error_handler();
235 }
236 
237 #ifdef _WIN32
238 
239 #define WIN32_NO_STATUS
240 #include "llvm/Support/Windows/WindowsSupport.h"
241 #undef WIN32_NO_STATUS
242 #include <ntstatus.h>
243 #include <winerror.h>
244 
245 // This is equivalent to NtCurrentTeb()->LastStatusValue, but the public
246 // _TEB definition does not expose the LastStatusValue field directly.
247 // Avoid offsetting into this structure by calling RtlGetLastNtStatus
248 // from ntdll.dll.
249 //
250 // The return of this function will roughly match that of
251 // GetLastError, but this lower level API disambiguates some cases
252 // that GetLastError does not.
253 //
254 // For more information, see:
255 // https://www.geoffchappell.com/studies/windows/km/ntoskrnl/inc/api/pebteb/teb/index.htm
256 // https://github.com/llvm/llvm-project/issues/89137
257 extern "C" NTSYSAPI NTSTATUS NTAPI RtlGetLastNtStatus();
258 
259 // This function obtains the last error code and maps it. It may call
260 // RtlGetLastNtStatus, which is a lower level API that can return a
261 // more specific error code than GetLastError.
262 std::error_code llvm::mapLastWindowsError() {
263   unsigned EV = ::GetLastError();
264   // The mapping of NTSTATUS to Win32 error loses some information; special
265   // case the generic ERROR_ACCESS_DENIED code to check the underlying
266   // NTSTATUS and potentially return a more accurate error code.
267   if (EV == ERROR_ACCESS_DENIED) {
268     llvm::errc code = RtlGetLastNtStatus() == STATUS_DELETE_PENDING
269                           ? errc::delete_pending
270                           : errc::permission_denied;
271     return make_error_code(code);
272   }
273   return mapWindowsError(EV);
274 }
275 
276 // I'd rather not double the line count of the following.
277 #define MAP_ERR_TO_COND(x, y)                                                  \
278   case x:                                                                      \
279     return make_error_code(errc::y)
280 
281 std::error_code llvm::mapWindowsError(unsigned EV) {
282   switch (EV) {
283     MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied);
284     MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists);
285     MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory);
286     MAP_ERR_TO_COND(ERROR_BAD_PATHNAME, no_such_file_or_directory);
287     MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device);
288     MAP_ERR_TO_COND(ERROR_BROKEN_PIPE, broken_pipe);
289     MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long);
290     MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy);
291     MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy);
292     MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied);
293     MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error);
294     MAP_ERR_TO_COND(ERROR_CANTREAD, io_error);
295     MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error);
296     MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied);
297     MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device);
298     MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy);
299     MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty);
300     MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument);
301     MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device);
302     MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);
303     MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);
304     MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);
305     MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);
306     MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);
307     MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);
308     MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument);
309     MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument);
310     MAP_ERR_TO_COND(ERROR_INVALID_PARAMETER, invalid_argument);
311     MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available);
312     MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available);
313     MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument);
314     MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied);
315     MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory);
316     MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again);
317     MAP_ERR_TO_COND(ERROR_NOT_SUPPORTED, not_supported);
318     MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error);
319     MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy);
320     MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory);
321     MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory);
322     MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error);
323     MAP_ERR_TO_COND(ERROR_REPARSE_TAG_INVALID, invalid_argument);
324     MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again);
325     MAP_ERR_TO_COND(ERROR_SEEK, io_error);
326     MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied);
327     MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);
328     MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error);
329     MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied);
330     MAP_ERR_TO_COND(WSAEACCES, permission_denied);
331     MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor);
332     MAP_ERR_TO_COND(WSAEFAULT, bad_address);
333     MAP_ERR_TO_COND(WSAEINTR, interrupted);
334     MAP_ERR_TO_COND(WSAEINVAL, invalid_argument);
335     MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open);
336     MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long);
337   default:
338     return std::error_code(EV, std::system_category());
339   }
340 }
341 
342 #endif
343