xref: /freebsd/contrib/llvm-project/llvm/lib/Support/Windows/Signals.inc (revision 1ed2ef42e01771f5d8ca9be61e07dcf0fd47feba) 
1//===- Win32/Signals.cpp - Win32 Signals Implementation ---------*- C++ -*-===//
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 provides the Win32 specific implementation of the Signals class.
10//
11//===----------------------------------------------------------------------===//
12#include "llvm/Config/llvm-config.h"
13#include "llvm/Support/ConvertUTF.h"
14#include "llvm/Support/ExitCodes.h"
15#include "llvm/Support/FileSystem.h"
16#include "llvm/Support/Path.h"
17#include "llvm/Support/Process.h"
18#include "llvm/Support/WindowsError.h"
19#include <algorithm>
20#include <io.h>
21#include <signal.h>
22#include <stdio.h>
23
24#include "llvm/Support/Format.h"
25#include "llvm/Support/raw_ostream.h"
26
27// The Windows.h header must be after LLVM and standard headers.
28#include "llvm/Support/Windows/WindowsSupport.h"
29
30#ifdef __MINGW32__
31#include <imagehlp.h>
32#else
33#include <crtdbg.h>
34#include <dbghelp.h>
35#endif
36#include <psapi.h>
37
38#ifdef _MSC_VER
39#pragma comment(lib, "psapi.lib")
40#elif __MINGW32__
41// The version of g++ that comes with MinGW does *not* properly understand
42// the ll format specifier for printf. However, MinGW passes the format
43// specifiers on to the MSVCRT entirely, and the CRT understands the ll
44// specifier. So these warnings are spurious in this case. Since we compile
45// with -Wall, this will generate these warnings which should be ignored. So
46// we will turn off the warnings for this just file. However, MinGW also does
47// not support push and pop for diagnostics, so we have to manually turn it
48// back on at the end of the file.
49#pragma GCC diagnostic ignored "-Wformat"
50#pragma GCC diagnostic ignored "-Wformat-extra-args"
51#endif // __MINGW32__
52
53typedef BOOL(__stdcall *PREAD_PROCESS_MEMORY_ROUTINE64)(
54    HANDLE hProcess, DWORD64 qwBaseAddress, PVOID lpBuffer, DWORD nSize,
55    LPDWORD lpNumberOfBytesRead);
56
57typedef PVOID(__stdcall *PFUNCTION_TABLE_ACCESS_ROUTINE64)(HANDLE ahProcess,
58                                                           DWORD64 AddrBase);
59
60typedef DWORD64(__stdcall *PGET_MODULE_BASE_ROUTINE64)(HANDLE hProcess,
61                                                       DWORD64 Address);
62
63typedef DWORD64(__stdcall *PTRANSLATE_ADDRESS_ROUTINE64)(HANDLE hProcess,
64                                                         HANDLE hThread,
65                                                         LPADDRESS64 lpaddr);
66
67typedef BOOL(WINAPI *fpMiniDumpWriteDump)(HANDLE, DWORD, HANDLE, MINIDUMP_TYPE,
68                                          PMINIDUMP_EXCEPTION_INFORMATION,
69                                          PMINIDUMP_USER_STREAM_INFORMATION,
70                                          PMINIDUMP_CALLBACK_INFORMATION);
71static fpMiniDumpWriteDump fMiniDumpWriteDump;
72
73typedef BOOL(WINAPI *fpStackWalk64)(DWORD, HANDLE, HANDLE, LPSTACKFRAME64,
74                                    PVOID, PREAD_PROCESS_MEMORY_ROUTINE64,
75                                    PFUNCTION_TABLE_ACCESS_ROUTINE64,
76                                    PGET_MODULE_BASE_ROUTINE64,
77                                    PTRANSLATE_ADDRESS_ROUTINE64);
78static fpStackWalk64 fStackWalk64;
79
80typedef DWORD64(WINAPI *fpSymGetModuleBase64)(HANDLE, DWORD64);
81static fpSymGetModuleBase64 fSymGetModuleBase64;
82
83typedef BOOL(WINAPI *fpSymGetSymFromAddr64)(HANDLE, DWORD64, PDWORD64,
84                                            PIMAGEHLP_SYMBOL64);
85static fpSymGetSymFromAddr64 fSymGetSymFromAddr64;
86
87typedef BOOL(WINAPI *fpSymGetLineFromAddr64)(HANDLE, DWORD64, PDWORD,
88                                             PIMAGEHLP_LINE64);
89static fpSymGetLineFromAddr64 fSymGetLineFromAddr64;
90
91typedef BOOL(WINAPI *fpSymGetModuleInfo64)(HANDLE hProcess, DWORD64 dwAddr,
92                                           PIMAGEHLP_MODULE64 ModuleInfo);
93static fpSymGetModuleInfo64 fSymGetModuleInfo64;
94
95typedef PVOID(WINAPI *fpSymFunctionTableAccess64)(HANDLE, DWORD64);
96static fpSymFunctionTableAccess64 fSymFunctionTableAccess64;
97
98typedef DWORD(WINAPI *fpSymSetOptions)(DWORD);
99static fpSymSetOptions fSymSetOptions;
100
101typedef BOOL(WINAPI *fpSymInitialize)(HANDLE, PCSTR, BOOL);
102static fpSymInitialize fSymInitialize;
103
104typedef BOOL(WINAPI *fpEnumerateLoadedModules)(HANDLE,
105                                               PENUMLOADED_MODULES_CALLBACK64,
106                                               PVOID);
107static fpEnumerateLoadedModules fEnumerateLoadedModules;
108
109static bool isDebugHelpInitialized() {
110  return fStackWalk64 && fSymInitialize && fSymSetOptions && fMiniDumpWriteDump;
111}
112
113static bool load64BitDebugHelp(void) {
114  HMODULE hLib =
115      ::LoadLibraryExA("Dbghelp.dll", NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
116  if (hLib) {
117    fMiniDumpWriteDump = (fpMiniDumpWriteDump)(void *)::GetProcAddress(
118        hLib, "MiniDumpWriteDump");
119    fStackWalk64 = (fpStackWalk64)(void *)::GetProcAddress(hLib, "StackWalk64");
120    fSymGetModuleBase64 = (fpSymGetModuleBase64)(void *)::GetProcAddress(
121        hLib, "SymGetModuleBase64");
122    fSymGetSymFromAddr64 = (fpSymGetSymFromAddr64)(void *)::GetProcAddress(
123        hLib, "SymGetSymFromAddr64");
124    fSymGetLineFromAddr64 = (fpSymGetLineFromAddr64)(void *)::GetProcAddress(
125        hLib, "SymGetLineFromAddr64");
126    fSymGetModuleInfo64 = (fpSymGetModuleInfo64)(void *)::GetProcAddress(
127        hLib, "SymGetModuleInfo64");
128    fSymFunctionTableAccess64 =
129        (fpSymFunctionTableAccess64)(void *)::GetProcAddress(
130            hLib, "SymFunctionTableAccess64");
131    fSymSetOptions =
132        (fpSymSetOptions)(void *)::GetProcAddress(hLib, "SymSetOptions");
133    fSymInitialize =
134        (fpSymInitialize)(void *)::GetProcAddress(hLib, "SymInitialize");
135    fEnumerateLoadedModules =
136        (fpEnumerateLoadedModules)(void *)::GetProcAddress(
137            hLib, "EnumerateLoadedModules64");
138  }
139  return isDebugHelpInitialized();
140}
141
142using namespace llvm;
143
144// Forward declare.
145static LONG WINAPI LLVMUnhandledExceptionFilter(LPEXCEPTION_POINTERS ep);
146static BOOL WINAPI LLVMConsoleCtrlHandler(DWORD dwCtrlType);
147
148// The function to call if ctrl-c is pressed.
149static void (*InterruptFunction)() = 0;
150
151static std::vector<std::string> *FilesToRemove = NULL;
152static bool RegisteredUnhandledExceptionFilter = false;
153static bool CleanupExecuted = false;
154static PTOP_LEVEL_EXCEPTION_FILTER OldFilter = NULL;
155
156/// The function to call on "SIGPIPE" (one-time use only).
157static std::atomic<void (*)()> OneShotPipeSignalFunction(nullptr);
158
159// Windows creates a new thread to execute the console handler when an event
160// (such as CTRL/C) occurs.  This causes concurrency issues with the above
161// globals which this critical section addresses.
162static CRITICAL_SECTION CriticalSection;
163static bool CriticalSectionInitialized = false;
164
165static StringRef Argv0;
166
167enum {
168#if defined(_M_X64)
169  NativeMachineType = IMAGE_FILE_MACHINE_AMD64
170#elif defined(_M_ARM64)
171  NativeMachineType = IMAGE_FILE_MACHINE_ARM64
172#elif defined(_M_IX86)
173  NativeMachineType = IMAGE_FILE_MACHINE_I386
174#elif defined(_M_ARM)
175  NativeMachineType = IMAGE_FILE_MACHINE_ARMNT
176#else
177  NativeMachineType = IMAGE_FILE_MACHINE_UNKNOWN
178#endif
179};
180
181static bool printStackTraceWithLLVMSymbolizer(llvm::raw_ostream &OS,
182                                              HANDLE hProcess, HANDLE hThread,
183                                              STACKFRAME64 &StackFrameOrig,
184                                              CONTEXT *ContextOrig) {
185  // StackWalk64 modifies the incoming stack frame and context, so copy them.
186  STACKFRAME64 StackFrame = StackFrameOrig;
187
188  // Copy the register context so that we don't modify it while we unwind. We
189  // could use InitializeContext + CopyContext, but that's only required to get
190  // at AVX registers, which typically aren't needed by StackWalk64. Reduce the
191  // flag set to indicate that there's less data.
192  CONTEXT Context = *ContextOrig;
193  Context.ContextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER;
194
195  static void *StackTrace[256];
196  size_t Depth = 0;
197  while (fStackWalk64(NativeMachineType, hProcess, hThread, &StackFrame,
198                      &Context, 0, fSymFunctionTableAccess64,
199                      fSymGetModuleBase64, 0)) {
200    if (StackFrame.AddrFrame.Offset == 0)
201      break;
202    StackTrace[Depth++] = (void *)(uintptr_t)StackFrame.AddrPC.Offset;
203    if (Depth >= std::size(StackTrace))
204      break;
205  }
206
207  return printSymbolizedStackTrace(Argv0, &StackTrace[0], Depth, OS);
208}
209
210namespace {
211struct FindModuleData {
212  void **StackTrace;
213  int Depth;
214  const char **Modules;
215  intptr_t *Offsets;
216  StringSaver *StrPool;
217};
218} // namespace
219
220static BOOL CALLBACK findModuleCallback(PCSTR ModuleName, DWORD64 ModuleBase,
221                                        ULONG ModuleSize, void *VoidData) {
222  FindModuleData *Data = (FindModuleData *)VoidData;
223  intptr_t Beg = ModuleBase;
224  intptr_t End = Beg + ModuleSize;
225  for (int I = 0; I < Data->Depth; I++) {
226    if (Data->Modules[I])
227      continue;
228    intptr_t Addr = (intptr_t)Data->StackTrace[I];
229    if (Beg <= Addr && Addr < End) {
230      Data->Modules[I] = Data->StrPool->save(ModuleName).data();
231      Data->Offsets[I] = Addr - Beg;
232    }
233  }
234  return TRUE;
235}
236
237static bool findModulesAndOffsets(void **StackTrace, int Depth,
238                                  const char **Modules, intptr_t *Offsets,
239                                  const char *MainExecutableName,
240                                  StringSaver &StrPool) {
241  if (!fEnumerateLoadedModules)
242    return false;
243  FindModuleData Data;
244  Data.StackTrace = StackTrace;
245  Data.Depth = Depth;
246  Data.Modules = Modules;
247  Data.Offsets = Offsets;
248  Data.StrPool = &StrPool;
249  fEnumerateLoadedModules(GetCurrentProcess(), findModuleCallback, &Data);
250  return true;
251}
252
253static bool printMarkupContext(llvm::raw_ostream &OS,
254                               const char *MainExecutableName) {
255  return false;
256}
257
258static void PrintStackTraceForThread(llvm::raw_ostream &OS, HANDLE hProcess,
259                                     HANDLE hThread, STACKFRAME64 &StackFrame,
260                                     CONTEXT *Context) {
261  // It's possible that DbgHelp.dll hasn't been loaded yet (e.g. if this
262  // function is called before the main program called `llvm::InitLLVM`).
263  // In this case just return, not stacktrace will be printed.
264  if (!isDebugHelpInitialized())
265    return;
266
267  // Initialize the symbol handler.
268  fSymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_LOAD_LINES);
269  fSymInitialize(hProcess, NULL, TRUE);
270
271  // Try llvm-symbolizer first. llvm-symbolizer knows how to deal with both PDBs
272  // and DWARF, so it should do a good job regardless of what debug info or
273  // linker is in use.
274  if (printStackTraceWithLLVMSymbolizer(OS, hProcess, hThread, StackFrame,
275                                        Context)) {
276    return;
277  }
278
279  while (true) {
280    if (!fStackWalk64(NativeMachineType, hProcess, hThread, &StackFrame,
281                      Context, 0, fSymFunctionTableAccess64,
282                      fSymGetModuleBase64, 0)) {
283      break;
284    }
285
286    if (StackFrame.AddrFrame.Offset == 0)
287      break;
288
289    using namespace llvm;
290    // Print the PC in hexadecimal.
291    DWORD64 PC = StackFrame.AddrPC.Offset;
292#if defined(_M_X64) || defined(_M_ARM64)
293    OS << format("0x%016llX", PC);
294#elif defined(_M_IX86) || defined(_M_ARM)
295    OS << format("0x%08lX", static_cast<DWORD>(PC));
296#endif
297
298    // Verify the PC belongs to a module in this process.
299    if (!fSymGetModuleBase64(hProcess, PC)) {
300      OS << " <unknown module>\n";
301      continue;
302    }
303
304    IMAGEHLP_MODULE64 M;
305    memset(&M, 0, sizeof(IMAGEHLP_MODULE64));
306    M.SizeOfStruct = sizeof(IMAGEHLP_MODULE64);
307    if (fSymGetModuleInfo64(hProcess, fSymGetModuleBase64(hProcess, PC), &M)) {
308      DWORD64 const disp = PC - M.BaseOfImage;
309      OS << format(", %s(0x%016llX) + 0x%llX byte(s)",
310                   static_cast<char *>(M.ImageName), M.BaseOfImage,
311                   static_cast<long long>(disp));
312    } else {
313      OS << ", <unknown module>";
314    }
315
316    // Print the symbol name.
317    char buffer[512];
318    IMAGEHLP_SYMBOL64 *symbol = reinterpret_cast<IMAGEHLP_SYMBOL64 *>(buffer);
319    memset(symbol, 0, sizeof(IMAGEHLP_SYMBOL64));
320    symbol->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
321    symbol->MaxNameLength = 512 - sizeof(IMAGEHLP_SYMBOL64);
322
323    DWORD64 dwDisp;
324    if (!fSymGetSymFromAddr64(hProcess, PC, &dwDisp, symbol)) {
325      OS << '\n';
326      continue;
327    }
328
329    buffer[511] = 0;
330    OS << format(", %s() + 0x%llX byte(s)", static_cast<char *>(symbol->Name),
331                 static_cast<long long>(dwDisp));
332
333    // Print the source file and line number information.
334    IMAGEHLP_LINE64 line = {};
335    DWORD dwLineDisp;
336    line.SizeOfStruct = sizeof(line);
337    if (fSymGetLineFromAddr64(hProcess, PC, &dwLineDisp, &line)) {
338      OS << format(", %s, line %lu + 0x%lX byte(s)", line.FileName,
339                   line.LineNumber, dwLineDisp);
340    }
341
342    OS << '\n';
343  }
344}
345
346namespace llvm {
347
348//===----------------------------------------------------------------------===//
349//=== WARNING: Implementation here must contain only Win32 specific code
350//===          and must not be UNIX code
351//===----------------------------------------------------------------------===//
352
353#ifdef _MSC_VER
354/// Emulates hitting "retry" from an "abort, retry, ignore" CRT debug report
355/// dialog. "retry" raises an exception which ultimately triggers our stack
356/// dumper.
357static LLVM_ATTRIBUTE_UNUSED int
358AvoidMessageBoxHook(int ReportType, char *Message, int *Return) {
359  // Set *Return to the retry code for the return value of _CrtDbgReport:
360  // http://msdn.microsoft.com/en-us/library/8hyw4sy7(v=vs.71).aspx
361  // This may also trigger just-in-time debugging via DebugBreak().
362  if (Return)
363    *Return = 1;
364  // Don't call _CrtDbgReport.
365  return TRUE;
366}
367
368#endif
369
370extern "C" void HandleAbort(int Sig) {
371  if (Sig == SIGABRT) {
372    LLVM_BUILTIN_TRAP;
373  }
374}
375
376static void InitializeThreading() {
377  if (CriticalSectionInitialized)
378    return;
379
380  // Now's the time to create the critical section. This is the first time
381  // through here, and there's only one thread.
382  InitializeCriticalSection(&CriticalSection);
383  CriticalSectionInitialized = true;
384}
385
386static void RegisterHandler() {
387  // If we cannot load up the APIs (which would be unexpected as they should
388  // exist on every version of Windows we support), we will bail out since
389  // there would be nothing to report.
390  if (!load64BitDebugHelp()) {
391    assert(false && "These APIs should always be available");
392    return;
393  }
394
395  if (RegisteredUnhandledExceptionFilter) {
396    EnterCriticalSection(&CriticalSection);
397    return;
398  }
399
400  InitializeThreading();
401
402  // Enter it immediately.  Now if someone hits CTRL/C, the console handler
403  // can't proceed until the globals are updated.
404  EnterCriticalSection(&CriticalSection);
405
406  RegisteredUnhandledExceptionFilter = true;
407  OldFilter = SetUnhandledExceptionFilter(LLVMUnhandledExceptionFilter);
408  SetConsoleCtrlHandler(LLVMConsoleCtrlHandler, TRUE);
409
410  // IMPORTANT NOTE: Caller must call LeaveCriticalSection(&CriticalSection) or
411  // else multi-threading problems will ensue.
412}
413
414// The public API
415bool sys::RemoveFileOnSignal(StringRef Filename, std::string *ErrMsg) {
416  RegisterHandler();
417
418  if (CleanupExecuted) {
419    if (ErrMsg)
420      *ErrMsg = "Process terminating -- cannot register for removal";
421    return true;
422  }
423
424  if (FilesToRemove == NULL)
425    FilesToRemove = new std::vector<std::string>;
426
427  FilesToRemove->push_back(std::string(Filename));
428
429  LeaveCriticalSection(&CriticalSection);
430  return false;
431}
432
433// The public API
434void sys::DontRemoveFileOnSignal(StringRef Filename) {
435  if (FilesToRemove == NULL)
436    return;
437
438  RegisterHandler();
439
440  std::vector<std::string>::reverse_iterator I =
441      find(reverse(*FilesToRemove), Filename);
442  if (I != FilesToRemove->rend())
443    FilesToRemove->erase(I.base() - 1);
444
445  LeaveCriticalSection(&CriticalSection);
446}
447
448void sys::DisableSystemDialogsOnCrash() {
449  // Crash to stack trace handler on abort.
450  signal(SIGABRT, HandleAbort);
451
452  // The following functions are not reliably accessible on MinGW.
453#ifdef _MSC_VER
454  // We're already handling writing a "something went wrong" message.
455  _set_abort_behavior(0, _WRITE_ABORT_MSG);
456  // Disable Dr. Watson.
457  _set_abort_behavior(0, _CALL_REPORTFAULT);
458  _CrtSetReportHook(AvoidMessageBoxHook);
459#endif
460
461  // Disable standard error dialog box.
462  SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX |
463               SEM_NOOPENFILEERRORBOX);
464  _set_error_mode(_OUT_TO_STDERR);
465}
466
467/// When an error signal (such as SIGABRT or SIGSEGV) is delivered to the
468/// process, print a stack trace and then exit.
469void sys::PrintStackTraceOnErrorSignal(StringRef Argv0,
470                                       bool DisableCrashReporting) {
471  ::Argv0 = Argv0;
472
473  if (DisableCrashReporting || getenv("LLVM_DISABLE_CRASH_REPORT"))
474    Process::PreventCoreFiles();
475
476  DisableSystemDialogsOnCrash();
477  RegisterHandler();
478  LeaveCriticalSection(&CriticalSection);
479}
480} // namespace llvm
481
482#if LLVM_ENABLE_DEBUGLOC_TRACKING_ORIGIN
483#error DebugLoc origin-tracking currently unimplemented for Windows.
484#endif
485
486static void LocalPrintStackTrace(raw_ostream &OS, PCONTEXT C) {
487  STACKFRAME64 StackFrame{};
488  CONTEXT Context{};
489  if (!C) {
490    ::RtlCaptureContext(&Context);
491    C = &Context;
492  }
493#if defined(_M_X64)
494  StackFrame.AddrPC.Offset = Context.Rip;
495  StackFrame.AddrStack.Offset = Context.Rsp;
496  StackFrame.AddrFrame.Offset = Context.Rbp;
497#elif defined(_M_IX86)
498  StackFrame.AddrPC.Offset = Context.Eip;
499  StackFrame.AddrStack.Offset = Context.Esp;
500  StackFrame.AddrFrame.Offset = Context.Ebp;
501#elif defined(_M_ARM64)
502  StackFrame.AddrPC.Offset = Context.Pc;
503  StackFrame.AddrStack.Offset = Context.Sp;
504  StackFrame.AddrFrame.Offset = Context.Fp;
505#elif defined(_M_ARM)
506  StackFrame.AddrPC.Offset = Context.Pc;
507  StackFrame.AddrStack.Offset = Context.Sp;
508  StackFrame.AddrFrame.Offset = Context.R11;
509#endif
510  StackFrame.AddrPC.Mode = AddrModeFlat;
511  StackFrame.AddrStack.Mode = AddrModeFlat;
512  StackFrame.AddrFrame.Mode = AddrModeFlat;
513  PrintStackTraceForThread(OS, GetCurrentProcess(), GetCurrentThread(),
514                           StackFrame, C);
515}
516
517void llvm::sys::PrintStackTrace(raw_ostream &OS, int Depth) {
518  // FIXME: Handle "Depth" parameter to print stack trace upto specified Depth
519  LocalPrintStackTrace(OS, nullptr);
520}
521
522void llvm::sys::SetInterruptFunction(void (*IF)()) {
523  RegisterHandler();
524  InterruptFunction = IF;
525  LeaveCriticalSection(&CriticalSection);
526}
527
528void llvm::sys::SetInfoSignalFunction(void (*Handler)()) {
529  // Unimplemented.
530}
531
532void llvm::sys::SetOneShotPipeSignalFunction(void (*Handler)()) {
533  OneShotPipeSignalFunction.exchange(Handler);
534}
535
536void llvm::sys::DefaultOneShotPipeSignalHandler() {
537  llvm::sys::Process::Exit(EX_IOERR, /*NoCleanup=*/true);
538}
539
540void llvm::sys::CallOneShotPipeSignalHandler() {
541  if (auto OldOneShotPipeFunction = OneShotPipeSignalFunction.exchange(nullptr))
542    OldOneShotPipeFunction();
543}
544
545/// Add a function to be called when a signal is delivered to the process. The
546/// handler can have a cookie passed to it to identify what instance of the
547/// handler it is.
548void llvm::sys::AddSignalHandler(sys::SignalHandlerCallback FnPtr,
549                                 void *Cookie) {
550  insertSignalHandler(FnPtr, Cookie);
551  RegisterHandler();
552  LeaveCriticalSection(&CriticalSection);
553}
554
555static void Cleanup(bool ExecuteSignalHandlers) {
556  if (CleanupExecuted)
557    return;
558
559  EnterCriticalSection(&CriticalSection);
560
561  // Prevent other thread from registering new files and directories for
562  // removal, should we be executing because of the console handler callback.
563  CleanupExecuted = true;
564
565  // FIXME: open files cannot be deleted.
566  if (FilesToRemove != NULL)
567    while (!FilesToRemove->empty()) {
568      llvm::sys::fs::remove(FilesToRemove->back());
569      FilesToRemove->pop_back();
570    }
571
572  if (ExecuteSignalHandlers)
573    llvm::sys::RunSignalHandlers();
574
575  LeaveCriticalSection(&CriticalSection);
576}
577
578void llvm::sys::RunInterruptHandlers() {
579  // The interrupt handler may be called from an interrupt, but it may also be
580  // called manually (such as the case of report_fatal_error with no registered
581  // error handler). We must ensure that the critical section is properly
582  // initialized.
583  InitializeThreading();
584  Cleanup(true);
585}
586
587/// Find the Windows Registry Key for a given location.
588///
589/// \returns a valid HKEY if the location exists, else NULL.
590static HKEY FindWERKey(const llvm::Twine &RegistryLocation) {
591  HKEY Key;
592  if (ERROR_SUCCESS != ::RegOpenKeyExA(HKEY_LOCAL_MACHINE,
593                                       RegistryLocation.str().c_str(), 0,
594                                       KEY_QUERY_VALUE | KEY_READ, &Key))
595    return NULL;
596
597  return Key;
598}
599
600/// Populate ResultDirectory with the value for "DumpFolder" for a given
601/// Windows Registry key.
602///
603/// \returns true if a valid value for DumpFolder exists, false otherwise.
604static bool GetDumpFolder(HKEY Key,
605                          llvm::SmallVectorImpl<char> &ResultDirectory) {
606  using llvm::sys::windows::UTF16ToUTF8;
607
608  if (!Key)
609    return false;
610
611  DWORD BufferLengthBytes = 0;
612
613  if (ERROR_SUCCESS != ::RegGetValueW(Key, 0, L"DumpFolder", REG_EXPAND_SZ,
614                                      NULL, NULL, &BufferLengthBytes))
615    return false;
616
617  SmallVector<wchar_t, MAX_PATH> Buffer(BufferLengthBytes);
618
619  if (ERROR_SUCCESS != ::RegGetValueW(Key, 0, L"DumpFolder", REG_EXPAND_SZ,
620                                      NULL, Buffer.data(), &BufferLengthBytes))
621    return false;
622
623  DWORD ExpandBufferSize = ::ExpandEnvironmentStringsW(Buffer.data(), NULL, 0);
624
625  if (!ExpandBufferSize)
626    return false;
627
628  SmallVector<wchar_t, MAX_PATH> ExpandBuffer(ExpandBufferSize);
629
630  if (ExpandBufferSize != ::ExpandEnvironmentStringsW(Buffer.data(),
631                                                      ExpandBuffer.data(),
632                                                      ExpandBufferSize))
633    return false;
634
635  if (UTF16ToUTF8(ExpandBuffer.data(), ExpandBufferSize - 1, ResultDirectory))
636    return false;
637
638  return true;
639}
640
641/// Populate ResultType with a valid MINIDUMP_TYPE based on the value of
642/// "DumpType" for a given Windows Registry key.
643///
644/// According to
645/// https://msdn.microsoft.com/en-us/library/windows/desktop/bb787181(v=vs.85).aspx
646/// valid values for DumpType are:
647///   * 0: Custom dump
648///   * 1: Mini dump
649///   * 2: Full dump
650/// If "Custom dump" is specified then the "CustomDumpFlags" field is read
651/// containing a bitwise combination of MINIDUMP_TYPE values.
652///
653/// \returns true if a valid value for ResultType can be set, false otherwise.
654static bool GetDumpType(HKEY Key, MINIDUMP_TYPE &ResultType) {
655  if (!Key)
656    return false;
657
658  DWORD DumpType;
659  DWORD TypeSize = sizeof(DumpType);
660  if (ERROR_SUCCESS != ::RegGetValueW(Key, NULL, L"DumpType", RRF_RT_REG_DWORD,
661                                      NULL, &DumpType, &TypeSize))
662    return false;
663
664  switch (DumpType) {
665  case 0: {
666    DWORD Flags = 0;
667    if (ERROR_SUCCESS != ::RegGetValueW(Key, NULL, L"CustomDumpFlags",
668                                        RRF_RT_REG_DWORD, NULL, &Flags,
669                                        &TypeSize))
670      return false;
671
672    ResultType = static_cast<MINIDUMP_TYPE>(Flags);
673    break;
674  }
675  case 1:
676    ResultType = MiniDumpNormal;
677    break;
678  case 2:
679    ResultType = MiniDumpWithFullMemory;
680    break;
681  default:
682    return false;
683  }
684  return true;
685}
686
687/// Write a Windows dump file containing process information that can be
688/// used for post-mortem debugging.
689///
690/// \returns zero error code if a mini dump created, actual error code
691/// otherwise.
692static std::error_code WINAPI
693WriteWindowsDumpFile(PMINIDUMP_EXCEPTION_INFORMATION ExceptionInfo) {
694  struct ScopedCriticalSection {
695    ScopedCriticalSection() { EnterCriticalSection(&CriticalSection); }
696    ~ScopedCriticalSection() { LeaveCriticalSection(&CriticalSection); }
697  } SCS;
698
699  using namespace llvm;
700  using namespace llvm::sys;
701
702  std::string MainExecutableName = fs::getMainExecutable(nullptr, nullptr);
703  StringRef ProgramName;
704
705  if (MainExecutableName.empty()) {
706    // If we can't get the executable filename,
707    // things are in worse shape than we realize
708    // and we should just bail out.
709    return mapWindowsError(::GetLastError());
710  }
711
712  ProgramName = path::filename(MainExecutableName.c_str());
713
714  // The Windows Registry location as specified at
715  // https://msdn.microsoft.com/en-us/library/windows/desktop/bb787181%28v=vs.85%29.aspx
716  // "Collecting User-Mode Dumps" that may optionally be set to collect crash
717  // dumps in a specified location.
718  StringRef LocalDumpsRegistryLocation =
719      "SOFTWARE\\Microsoft\\Windows\\Windows Error Reporting\\LocalDumps";
720
721  // The key pointing to the Registry location that may contain global crash
722  // dump settings.  This will be NULL if the location can not be found.
723  ScopedRegHandle DefaultLocalDumpsKey(FindWERKey(LocalDumpsRegistryLocation));
724
725  // The key pointing to the Registry location that may contain
726  // application-specific crash dump settings.  This will be NULL if the
727  // location can not be found.
728  ScopedRegHandle AppSpecificKey(
729      FindWERKey(Twine(LocalDumpsRegistryLocation) + "\\" + ProgramName));
730
731  // Look to see if a dump type is specified in the registry; first with the
732  // app-specific key and failing that with the global key.  If none are found
733  // default to a normal dump (GetDumpType will return false either if the key
734  // is NULL or if there is no valid DumpType value at its location).
735  MINIDUMP_TYPE DumpType;
736  if (!GetDumpType(AppSpecificKey, DumpType))
737    if (!GetDumpType(DefaultLocalDumpsKey, DumpType))
738      DumpType = MiniDumpNormal;
739
740  // Look to see if a dump location is specified on the command line.  If not,
741  // look to see if a dump location is specified in the registry; first with the
742  // app-specific key and failing that with the global key.  If none are found
743  // we'll just create the dump file in the default temporary file location
744  // (GetDumpFolder will return false either if the key is NULL or if there is
745  // no valid DumpFolder value at its location).
746  bool ExplicitDumpDirectorySet = true;
747  SmallString<MAX_PATH> DumpDirectory(*CrashDiagnosticsDirectory);
748  if (DumpDirectory.empty())
749    if (!GetDumpFolder(AppSpecificKey, DumpDirectory))
750      if (!GetDumpFolder(DefaultLocalDumpsKey, DumpDirectory))
751        ExplicitDumpDirectorySet = false;
752
753  int FD;
754  SmallString<MAX_PATH> DumpPath;
755
756  if (ExplicitDumpDirectorySet) {
757    if (std::error_code EC = fs::create_directories(DumpDirectory))
758      return EC;
759    if (std::error_code EC = fs::createUniqueFile(
760            Twine(DumpDirectory) + "\\" + ProgramName + ".%%%%%%.dmp", FD,
761            DumpPath))
762      return EC;
763  } else if (std::error_code EC =
764                 fs::createTemporaryFile(ProgramName, "dmp", FD, DumpPath))
765    return EC;
766
767  // Our support functions return a file descriptor but Windows wants a handle.
768  ScopedCommonHandle FileHandle(reinterpret_cast<HANDLE>(_get_osfhandle(FD)));
769
770  if (!fMiniDumpWriteDump(::GetCurrentProcess(), ::GetCurrentProcessId(),
771                          FileHandle, DumpType, ExceptionInfo, NULL, NULL))
772    return mapWindowsError(::GetLastError());
773
774  llvm::errs() << "Wrote crash dump file \"" << DumpPath << "\"\n";
775  return std::error_code();
776}
777
778void sys::CleanupOnSignal(uintptr_t Context) {
779  LPEXCEPTION_POINTERS EP = (LPEXCEPTION_POINTERS)Context;
780  // Broken pipe is not a crash.
781  //
782  // 0xE0000000 is combined with the return code in the exception raised in
783  // CrashRecoveryContext::HandleExit().
784  unsigned RetCode = EP->ExceptionRecord->ExceptionCode;
785  if (RetCode == (0xE0000000 | EX_IOERR))
786    return;
787  LLVMUnhandledExceptionFilter(EP);
788}
789
790static LONG WINAPI LLVMUnhandledExceptionFilter(LPEXCEPTION_POINTERS ep) {
791  Cleanup(true);
792
793  // Write out the exception code.
794  if (ep && ep->ExceptionRecord)
795    llvm::errs() << format("Exception Code: 0x%08X",
796                           ep->ExceptionRecord->ExceptionCode)
797                 << "\n";
798
799  // We'll automatically write a Minidump file here to help diagnose
800  // the nasty sorts of crashes that aren't 100% reproducible from a set of
801  // inputs (or in the event that the user is unable or unwilling to provide a
802  // reproducible case).
803  if (!llvm::sys::Process::AreCoreFilesPrevented()) {
804    MINIDUMP_EXCEPTION_INFORMATION ExceptionInfo;
805    ExceptionInfo.ThreadId = ::GetCurrentThreadId();
806    ExceptionInfo.ExceptionPointers = ep;
807    ExceptionInfo.ClientPointers = FALSE;
808
809    if (std::error_code EC = WriteWindowsDumpFile(&ExceptionInfo))
810      llvm::errs() << "Could not write crash dump file: " << EC.message()
811                   << "\n";
812  }
813
814  // Stack unwinding appears to modify the context. Copy it to preserve the
815  // caller's context.
816  CONTEXT ContextCopy;
817  if (ep)
818    memcpy(&ContextCopy, ep->ContextRecord, sizeof(ContextCopy));
819
820  LocalPrintStackTrace(llvm::errs(), ep ? &ContextCopy : nullptr);
821
822  return EXCEPTION_EXECUTE_HANDLER;
823}
824
825static BOOL WINAPI LLVMConsoleCtrlHandler(DWORD dwCtrlType) {
826  // We are running in our very own thread, courtesy of Windows.
827  EnterCriticalSection(&CriticalSection);
828  // This function is only ever called when a CTRL-C or similar control signal
829  // is fired. Killing a process in this way is normal, so don't trigger the
830  // signal handlers.
831  Cleanup(false);
832
833  // If an interrupt function has been set, go and run one it; otherwise,
834  // the process dies.
835  void (*IF)() = InterruptFunction;
836  InterruptFunction = 0; // Don't run it on another CTRL-C.
837
838  if (IF) {
839    // Note: if the interrupt function throws an exception, there is nothing
840    // to catch it in this thread so it will kill the process.
841    IF(); // Run it now.
842    LeaveCriticalSection(&CriticalSection);
843    return TRUE; // Don't kill the process.
844  }
845
846  // Allow normal processing to take place; i.e., the process dies.
847  LeaveCriticalSection(&CriticalSection);
848  return FALSE;
849}
850
851#if __MINGW32__
852// We turned these warnings off for this file so that MinGW-g++ doesn't
853// complain about the ll format specifiers used.  Now we are turning the
854// warnings back on.  If MinGW starts to support diagnostic stacks, we can
855// replace this with a pop.
856#pragma GCC diagnostic warning "-Wformat"
857#pragma GCC diagnostic warning "-Wformat-extra-args"
858#endif
859
860void sys::unregisterHandlers() {}
861