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/Support/ConvertUTF.h"
13#include "llvm/Support/ExitCodes.h"
14#include "llvm/Support/FileSystem.h"
15#include "llvm/Support/Path.h"
16#include "llvm/Support/Process.h"
17#include "llvm/Support/WindowsError.h"
18#include <algorithm>
19#include <io.h>
20#include <signal.h>
21#include <stdio.h>
22
23#include "llvm/Support/Format.h"
24#include "llvm/Support/raw_ostream.h"
25
26// The Windows.h header must be after LLVM and standard headers.
27#include "llvm/Support/Windows/WindowsSupport.h"
28
29#ifdef __MINGW32__
30#include <imagehlp.h>
31#else
32#include <crtdbg.h>
33#include <dbghelp.h>
34#endif
35#include <psapi.h>
36
37#ifdef _MSC_VER
38#pragma comment(lib, "psapi.lib")
39#elif __MINGW32__
40// The version of g++ that comes with MinGW does *not* properly understand
41// the ll format specifier for printf. However, MinGW passes the format
42// specifiers on to the MSVCRT entirely, and the CRT understands the ll
43// specifier. So these warnings are spurious in this case. Since we compile
44// with -Wall, this will generate these warnings which should be ignored. So
45// we will turn off the warnings for this just file. However, MinGW also does
46// not support push and pop for diagnostics, so we have to manually turn it
47// back on at the end of the file.
48#pragma GCC diagnostic ignored "-Wformat"
49#pragma GCC diagnostic ignored "-Wformat-extra-args"
50
51#if !defined(__MINGW64_VERSION_MAJOR)
52// MinGW.org does not have updated support for the 64-bit versions of the
53// DebugHlp APIs. So we will have to load them manually. The structures and
54// method signatures were pulled from DbgHelp.h in the Windows Platform SDK,
55// and adjusted for brevity.
56typedef struct _IMAGEHLP_LINE64 {
57  DWORD SizeOfStruct;
58  PVOID Key;
59  DWORD LineNumber;
60  PCHAR FileName;
61  DWORD64 Address;
62} IMAGEHLP_LINE64, *PIMAGEHLP_LINE64;
63
64typedef struct _IMAGEHLP_SYMBOL64 {
65  DWORD SizeOfStruct;
66  DWORD64 Address;
67  DWORD Size;
68  DWORD Flags;
69  DWORD MaxNameLength;
70  CHAR Name[1];
71} IMAGEHLP_SYMBOL64, *PIMAGEHLP_SYMBOL64;
72
73typedef struct _tagADDRESS64 {
74  DWORD64 Offset;
75  WORD Segment;
76  ADDRESS_MODE Mode;
77} ADDRESS64, *LPADDRESS64;
78
79typedef struct _KDHELP64 {
80  DWORD64 Thread;
81  DWORD ThCallbackStack;
82  DWORD ThCallbackBStore;
83  DWORD NextCallback;
84  DWORD FramePointer;
85  DWORD64 KiCallUserMode;
86  DWORD64 KeUserCallbackDispatcher;
87  DWORD64 SystemRangeStart;
88  DWORD64 KiUserExceptionDispatcher;
89  DWORD64 StackBase;
90  DWORD64 StackLimit;
91  DWORD64 Reserved[5];
92} KDHELP64, *PKDHELP64;
93
94typedef struct _tagSTACKFRAME64 {
95  ADDRESS64 AddrPC;
96  ADDRESS64 AddrReturn;
97  ADDRESS64 AddrFrame;
98  ADDRESS64 AddrStack;
99  ADDRESS64 AddrBStore;
100  PVOID FuncTableEntry;
101  DWORD64 Params[4];
102  BOOL Far;
103  BOOL Virtual;
104  DWORD64 Reserved[3];
105  KDHELP64 KdHelp;
106} STACKFRAME64, *LPSTACKFRAME64;
107#endif // !defined(__MINGW64_VERSION_MAJOR)
108#endif // __MINGW32__
109
110typedef BOOL(__stdcall *PREAD_PROCESS_MEMORY_ROUTINE64)(
111    HANDLE hProcess, DWORD64 qwBaseAddress, PVOID lpBuffer, DWORD nSize,
112    LPDWORD lpNumberOfBytesRead);
113
114typedef PVOID(__stdcall *PFUNCTION_TABLE_ACCESS_ROUTINE64)(HANDLE ahProcess,
115                                                           DWORD64 AddrBase);
116
117typedef DWORD64(__stdcall *PGET_MODULE_BASE_ROUTINE64)(HANDLE hProcess,
118                                                       DWORD64 Address);
119
120typedef DWORD64(__stdcall *PTRANSLATE_ADDRESS_ROUTINE64)(HANDLE hProcess,
121                                                         HANDLE hThread,
122                                                         LPADDRESS64 lpaddr);
123
124typedef BOOL(WINAPI *fpMiniDumpWriteDump)(HANDLE, DWORD, HANDLE, MINIDUMP_TYPE,
125                                          PMINIDUMP_EXCEPTION_INFORMATION,
126                                          PMINIDUMP_USER_STREAM_INFORMATION,
127                                          PMINIDUMP_CALLBACK_INFORMATION);
128static fpMiniDumpWriteDump fMiniDumpWriteDump;
129
130typedef BOOL(WINAPI *fpStackWalk64)(DWORD, HANDLE, HANDLE, LPSTACKFRAME64,
131                                    PVOID, PREAD_PROCESS_MEMORY_ROUTINE64,
132                                    PFUNCTION_TABLE_ACCESS_ROUTINE64,
133                                    PGET_MODULE_BASE_ROUTINE64,
134                                    PTRANSLATE_ADDRESS_ROUTINE64);
135static fpStackWalk64 fStackWalk64;
136
137typedef DWORD64(WINAPI *fpSymGetModuleBase64)(HANDLE, DWORD64);
138static fpSymGetModuleBase64 fSymGetModuleBase64;
139
140typedef BOOL(WINAPI *fpSymGetSymFromAddr64)(HANDLE, DWORD64, PDWORD64,
141                                            PIMAGEHLP_SYMBOL64);
142static fpSymGetSymFromAddr64 fSymGetSymFromAddr64;
143
144typedef BOOL(WINAPI *fpSymGetLineFromAddr64)(HANDLE, DWORD64, PDWORD,
145                                             PIMAGEHLP_LINE64);
146static fpSymGetLineFromAddr64 fSymGetLineFromAddr64;
147
148typedef BOOL(WINAPI *fpSymGetModuleInfo64)(HANDLE hProcess, DWORD64 dwAddr,
149                                           PIMAGEHLP_MODULE64 ModuleInfo);
150static fpSymGetModuleInfo64 fSymGetModuleInfo64;
151
152typedef PVOID(WINAPI *fpSymFunctionTableAccess64)(HANDLE, DWORD64);
153static fpSymFunctionTableAccess64 fSymFunctionTableAccess64;
154
155typedef DWORD(WINAPI *fpSymSetOptions)(DWORD);
156static fpSymSetOptions fSymSetOptions;
157
158typedef BOOL(WINAPI *fpSymInitialize)(HANDLE, PCSTR, BOOL);
159static fpSymInitialize fSymInitialize;
160
161typedef BOOL(WINAPI *fpEnumerateLoadedModules)(HANDLE,
162                                               PENUMLOADED_MODULES_CALLBACK64,
163                                               PVOID);
164static fpEnumerateLoadedModules fEnumerateLoadedModules;
165
166static bool isDebugHelpInitialized() {
167  return fStackWalk64 && fSymInitialize && fSymSetOptions && fMiniDumpWriteDump;
168}
169
170static bool load64BitDebugHelp(void) {
171  HMODULE hLib = ::LoadLibraryW(L"Dbghelp.dll");
172  if (hLib) {
173    fMiniDumpWriteDump =
174        (fpMiniDumpWriteDump)::GetProcAddress(hLib, "MiniDumpWriteDump");
175    fStackWalk64 = (fpStackWalk64)::GetProcAddress(hLib, "StackWalk64");
176    fSymGetModuleBase64 =
177        (fpSymGetModuleBase64)::GetProcAddress(hLib, "SymGetModuleBase64");
178    fSymGetSymFromAddr64 =
179        (fpSymGetSymFromAddr64)::GetProcAddress(hLib, "SymGetSymFromAddr64");
180    fSymGetLineFromAddr64 =
181        (fpSymGetLineFromAddr64)::GetProcAddress(hLib, "SymGetLineFromAddr64");
182    fSymGetModuleInfo64 =
183        (fpSymGetModuleInfo64)::GetProcAddress(hLib, "SymGetModuleInfo64");
184    fSymFunctionTableAccess64 = (fpSymFunctionTableAccess64)::GetProcAddress(
185        hLib, "SymFunctionTableAccess64");
186    fSymSetOptions = (fpSymSetOptions)::GetProcAddress(hLib, "SymSetOptions");
187    fSymInitialize = (fpSymInitialize)::GetProcAddress(hLib, "SymInitialize");
188    fEnumerateLoadedModules = (fpEnumerateLoadedModules)::GetProcAddress(
189        hLib, "EnumerateLoadedModules64");
190  }
191  return isDebugHelpInitialized();
192}
193
194using namespace llvm;
195
196// Forward declare.
197static LONG WINAPI LLVMUnhandledExceptionFilter(LPEXCEPTION_POINTERS ep);
198static BOOL WINAPI LLVMConsoleCtrlHandler(DWORD dwCtrlType);
199
200// The function to call if ctrl-c is pressed.
201static void (*InterruptFunction)() = 0;
202
203static std::vector<std::string> *FilesToRemove = NULL;
204static bool RegisteredUnhandledExceptionFilter = false;
205static bool CleanupExecuted = false;
206static PTOP_LEVEL_EXCEPTION_FILTER OldFilter = NULL;
207
208/// The function to call on "SIGPIPE" (one-time use only).
209static std::atomic<void (*)()> OneShotPipeSignalFunction(nullptr);
210
211// Windows creates a new thread to execute the console handler when an event
212// (such as CTRL/C) occurs.  This causes concurrency issues with the above
213// globals which this critical section addresses.
214static CRITICAL_SECTION CriticalSection;
215static bool CriticalSectionInitialized = false;
216
217static StringRef Argv0;
218
219enum {
220#if defined(_M_X64)
221  NativeMachineType = IMAGE_FILE_MACHINE_AMD64
222#elif defined(_M_ARM64)
223  NativeMachineType = IMAGE_FILE_MACHINE_ARM64
224#elif defined(_M_IX86)
225  NativeMachineType = IMAGE_FILE_MACHINE_I386
226#elif defined(_M_ARM)
227  NativeMachineType = IMAGE_FILE_MACHINE_ARMNT
228#else
229  NativeMachineType = IMAGE_FILE_MACHINE_UNKNOWN
230#endif
231};
232
233static bool printStackTraceWithLLVMSymbolizer(llvm::raw_ostream &OS,
234                                              HANDLE hProcess, HANDLE hThread,
235                                              STACKFRAME64 &StackFrameOrig,
236                                              CONTEXT *ContextOrig) {
237  // StackWalk64 modifies the incoming stack frame and context, so copy them.
238  STACKFRAME64 StackFrame = StackFrameOrig;
239
240  // Copy the register context so that we don't modify it while we unwind. We
241  // could use InitializeContext + CopyContext, but that's only required to get
242  // at AVX registers, which typically aren't needed by StackWalk64. Reduce the
243  // flag set to indicate that there's less data.
244  CONTEXT Context = *ContextOrig;
245  Context.ContextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER;
246
247  static void *StackTrace[256];
248  size_t Depth = 0;
249  while (fStackWalk64(NativeMachineType, hProcess, hThread, &StackFrame,
250                      &Context, 0, fSymFunctionTableAccess64,
251                      fSymGetModuleBase64, 0)) {
252    if (StackFrame.AddrFrame.Offset == 0)
253      break;
254    StackTrace[Depth++] = (void *)(uintptr_t)StackFrame.AddrPC.Offset;
255    if (Depth >= std::size(StackTrace))
256      break;
257  }
258
259  return printSymbolizedStackTrace(Argv0, &StackTrace[0], Depth, OS);
260}
261
262namespace {
263struct FindModuleData {
264  void **StackTrace;
265  int Depth;
266  const char **Modules;
267  intptr_t *Offsets;
268  StringSaver *StrPool;
269};
270} // namespace
271
272static BOOL CALLBACK findModuleCallback(PCSTR ModuleName, DWORD64 ModuleBase,
273                                        ULONG ModuleSize, void *VoidData) {
274  FindModuleData *Data = (FindModuleData *)VoidData;
275  intptr_t Beg = ModuleBase;
276  intptr_t End = Beg + ModuleSize;
277  for (int I = 0; I < Data->Depth; I++) {
278    if (Data->Modules[I])
279      continue;
280    intptr_t Addr = (intptr_t)Data->StackTrace[I];
281    if (Beg <= Addr && Addr < End) {
282      Data->Modules[I] = Data->StrPool->save(ModuleName).data();
283      Data->Offsets[I] = Addr - Beg;
284    }
285  }
286  return TRUE;
287}
288
289static bool findModulesAndOffsets(void **StackTrace, int Depth,
290                                  const char **Modules, intptr_t *Offsets,
291                                  const char *MainExecutableName,
292                                  StringSaver &StrPool) {
293  if (!fEnumerateLoadedModules)
294    return false;
295  FindModuleData Data;
296  Data.StackTrace = StackTrace;
297  Data.Depth = Depth;
298  Data.Modules = Modules;
299  Data.Offsets = Offsets;
300  Data.StrPool = &StrPool;
301  fEnumerateLoadedModules(GetCurrentProcess(), findModuleCallback, &Data);
302  return true;
303}
304
305static bool printMarkupContext(llvm::raw_ostream &OS,
306                               const char *MainExecutableName) {
307  return false;
308}
309
310static void PrintStackTraceForThread(llvm::raw_ostream &OS, HANDLE hProcess,
311                                     HANDLE hThread, STACKFRAME64 &StackFrame,
312                                     CONTEXT *Context) {
313  // It's possible that DbgHelp.dll hasn't been loaded yet (e.g. if this
314  // function is called before the main program called `llvm::InitLLVM`).
315  // In this case just return, not stacktrace will be printed.
316  if (!isDebugHelpInitialized())
317    return;
318
319  // Initialize the symbol handler.
320  fSymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_LOAD_LINES);
321  fSymInitialize(hProcess, NULL, TRUE);
322
323  // Try llvm-symbolizer first. llvm-symbolizer knows how to deal with both PDBs
324  // and DWARF, so it should do a good job regardless of what debug info or
325  // linker is in use.
326  if (printStackTraceWithLLVMSymbolizer(OS, hProcess, hThread, StackFrame,
327                                        Context)) {
328    return;
329  }
330
331  while (true) {
332    if (!fStackWalk64(NativeMachineType, hProcess, hThread, &StackFrame,
333                      Context, 0, fSymFunctionTableAccess64,
334                      fSymGetModuleBase64, 0)) {
335      break;
336    }
337
338    if (StackFrame.AddrFrame.Offset == 0)
339      break;
340
341    using namespace llvm;
342    // Print the PC in hexadecimal.
343    DWORD64 PC = StackFrame.AddrPC.Offset;
344#if defined(_M_X64) || defined(_M_ARM64)
345    OS << format("0x%016llX", PC);
346#elif defined(_M_IX86) || defined(_M_ARM)
347    OS << format("0x%08lX", static_cast<DWORD>(PC));
348#endif
349
350    // Verify the PC belongs to a module in this process.
351    if (!fSymGetModuleBase64(hProcess, PC)) {
352      OS << " <unknown module>\n";
353      continue;
354    }
355
356    IMAGEHLP_MODULE64 M;
357    memset(&M, 0, sizeof(IMAGEHLP_MODULE64));
358    M.SizeOfStruct = sizeof(IMAGEHLP_MODULE64);
359    if (fSymGetModuleInfo64(hProcess, fSymGetModuleBase64(hProcess, PC), &M)) {
360      DWORD64 const disp = PC - M.BaseOfImage;
361      OS << format(", %s(0x%016llX) + 0x%llX byte(s)",
362                   static_cast<char *>(M.ImageName), M.BaseOfImage,
363                   static_cast<long long>(disp));
364    } else {
365      OS << ", <unknown module>";
366    }
367
368    // Print the symbol name.
369    char buffer[512];
370    IMAGEHLP_SYMBOL64 *symbol = reinterpret_cast<IMAGEHLP_SYMBOL64 *>(buffer);
371    memset(symbol, 0, sizeof(IMAGEHLP_SYMBOL64));
372    symbol->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
373    symbol->MaxNameLength = 512 - sizeof(IMAGEHLP_SYMBOL64);
374
375    DWORD64 dwDisp;
376    if (!fSymGetSymFromAddr64(hProcess, PC, &dwDisp, symbol)) {
377      OS << '\n';
378      continue;
379    }
380
381    buffer[511] = 0;
382    OS << format(", %s() + 0x%llX byte(s)", static_cast<char *>(symbol->Name),
383                 static_cast<long long>(dwDisp));
384
385    // Print the source file and line number information.
386    IMAGEHLP_LINE64 line = {};
387    DWORD dwLineDisp;
388    line.SizeOfStruct = sizeof(line);
389    if (fSymGetLineFromAddr64(hProcess, PC, &dwLineDisp, &line)) {
390      OS << format(", %s, line %lu + 0x%lX byte(s)", line.FileName,
391                   line.LineNumber, dwLineDisp);
392    }
393
394    OS << '\n';
395  }
396}
397
398namespace llvm {
399
400//===----------------------------------------------------------------------===//
401//=== WARNING: Implementation here must contain only Win32 specific code
402//===          and must not be UNIX code
403//===----------------------------------------------------------------------===//
404
405#ifdef _MSC_VER
406/// Emulates hitting "retry" from an "abort, retry, ignore" CRT debug report
407/// dialog. "retry" raises an exception which ultimately triggers our stack
408/// dumper.
409static LLVM_ATTRIBUTE_UNUSED int
410AvoidMessageBoxHook(int ReportType, char *Message, int *Return) {
411  // Set *Return to the retry code for the return value of _CrtDbgReport:
412  // http://msdn.microsoft.com/en-us/library/8hyw4sy7(v=vs.71).aspx
413  // This may also trigger just-in-time debugging via DebugBreak().
414  if (Return)
415    *Return = 1;
416  // Don't call _CrtDbgReport.
417  return TRUE;
418}
419
420#endif
421
422extern "C" void HandleAbort(int Sig) {
423  if (Sig == SIGABRT) {
424    LLVM_BUILTIN_TRAP;
425  }
426}
427
428static void InitializeThreading() {
429  if (CriticalSectionInitialized)
430    return;
431
432  // Now's the time to create the critical section. This is the first time
433  // through here, and there's only one thread.
434  InitializeCriticalSection(&CriticalSection);
435  CriticalSectionInitialized = true;
436}
437
438static void RegisterHandler() {
439  // If we cannot load up the APIs (which would be unexpected as they should
440  // exist on every version of Windows we support), we will bail out since
441  // there would be nothing to report.
442  if (!load64BitDebugHelp()) {
443    assert(false && "These APIs should always be available");
444    return;
445  }
446
447  if (RegisteredUnhandledExceptionFilter) {
448    EnterCriticalSection(&CriticalSection);
449    return;
450  }
451
452  InitializeThreading();
453
454  // Enter it immediately.  Now if someone hits CTRL/C, the console handler
455  // can't proceed until the globals are updated.
456  EnterCriticalSection(&CriticalSection);
457
458  RegisteredUnhandledExceptionFilter = true;
459  OldFilter = SetUnhandledExceptionFilter(LLVMUnhandledExceptionFilter);
460  SetConsoleCtrlHandler(LLVMConsoleCtrlHandler, TRUE);
461
462  // IMPORTANT NOTE: Caller must call LeaveCriticalSection(&CriticalSection) or
463  // else multi-threading problems will ensue.
464}
465
466// The public API
467bool sys::RemoveFileOnSignal(StringRef Filename, std::string *ErrMsg) {
468  RegisterHandler();
469
470  if (CleanupExecuted) {
471    if (ErrMsg)
472      *ErrMsg = "Process terminating -- cannot register for removal";
473    return true;
474  }
475
476  if (FilesToRemove == NULL)
477    FilesToRemove = new std::vector<std::string>;
478
479  FilesToRemove->push_back(std::string(Filename));
480
481  LeaveCriticalSection(&CriticalSection);
482  return false;
483}
484
485// The public API
486void sys::DontRemoveFileOnSignal(StringRef Filename) {
487  if (FilesToRemove == NULL)
488    return;
489
490  RegisterHandler();
491
492  std::vector<std::string>::reverse_iterator I =
493      find(reverse(*FilesToRemove), Filename);
494  if (I != FilesToRemove->rend())
495    FilesToRemove->erase(I.base() - 1);
496
497  LeaveCriticalSection(&CriticalSection);
498}
499
500void sys::DisableSystemDialogsOnCrash() {
501  // Crash to stack trace handler on abort.
502  signal(SIGABRT, HandleAbort);
503
504  // The following functions are not reliably accessible on MinGW.
505#ifdef _MSC_VER
506  // We're already handling writing a "something went wrong" message.
507  _set_abort_behavior(0, _WRITE_ABORT_MSG);
508  // Disable Dr. Watson.
509  _set_abort_behavior(0, _CALL_REPORTFAULT);
510  _CrtSetReportHook(AvoidMessageBoxHook);
511#endif
512
513  // Disable standard error dialog box.
514  SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX |
515               SEM_NOOPENFILEERRORBOX);
516  _set_error_mode(_OUT_TO_STDERR);
517}
518
519/// When an error signal (such as SIGABRT or SIGSEGV) is delivered to the
520/// process, print a stack trace and then exit.
521void sys::PrintStackTraceOnErrorSignal(StringRef Argv0,
522                                       bool DisableCrashReporting) {
523  ::Argv0 = Argv0;
524
525  if (DisableCrashReporting || getenv("LLVM_DISABLE_CRASH_REPORT"))
526    Process::PreventCoreFiles();
527
528  DisableSystemDialogsOnCrash();
529  RegisterHandler();
530  LeaveCriticalSection(&CriticalSection);
531}
532} // namespace llvm
533
534#if defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR)
535// Provide a prototype for RtlCaptureContext, mingw32 from mingw.org is
536// missing it but mingw-w64 has it.
537extern "C" VOID WINAPI RtlCaptureContext(PCONTEXT ContextRecord);
538#endif
539
540static void LocalPrintStackTrace(raw_ostream &OS, PCONTEXT C) {
541  STACKFRAME64 StackFrame{};
542  CONTEXT Context{};
543  if (!C) {
544    ::RtlCaptureContext(&Context);
545    C = &Context;
546  }
547#if defined(_M_X64)
548  StackFrame.AddrPC.Offset = Context.Rip;
549  StackFrame.AddrStack.Offset = Context.Rsp;
550  StackFrame.AddrFrame.Offset = Context.Rbp;
551#elif defined(_M_IX86)
552  StackFrame.AddrPC.Offset = Context.Eip;
553  StackFrame.AddrStack.Offset = Context.Esp;
554  StackFrame.AddrFrame.Offset = Context.Ebp;
555#elif defined(_M_ARM64)
556  StackFrame.AddrPC.Offset = Context.Pc;
557  StackFrame.AddrStack.Offset = Context.Sp;
558  StackFrame.AddrFrame.Offset = Context.Fp;
559#elif defined(_M_ARM)
560  StackFrame.AddrPC.Offset = Context.Pc;
561  StackFrame.AddrStack.Offset = Context.Sp;
562  StackFrame.AddrFrame.Offset = Context.R11;
563#endif
564  StackFrame.AddrPC.Mode = AddrModeFlat;
565  StackFrame.AddrStack.Mode = AddrModeFlat;
566  StackFrame.AddrFrame.Mode = AddrModeFlat;
567  PrintStackTraceForThread(OS, GetCurrentProcess(), GetCurrentThread(),
568                           StackFrame, C);
569}
570
571void llvm::sys::PrintStackTrace(raw_ostream &OS, int Depth) {
572  // FIXME: Handle "Depth" parameter to print stack trace upto specified Depth
573  LocalPrintStackTrace(OS, nullptr);
574}
575
576void llvm::sys::SetInterruptFunction(void (*IF)()) {
577  RegisterHandler();
578  InterruptFunction = IF;
579  LeaveCriticalSection(&CriticalSection);
580}
581
582void llvm::sys::SetInfoSignalFunction(void (*Handler)()) {
583  // Unimplemented.
584}
585
586void llvm::sys::SetOneShotPipeSignalFunction(void (*Handler)()) {
587  OneShotPipeSignalFunction.exchange(Handler);
588}
589
590void llvm::sys::DefaultOneShotPipeSignalHandler() {
591  llvm::sys::Process::Exit(EX_IOERR, /*NoCleanup=*/true);
592}
593
594void llvm::sys::CallOneShotPipeSignalHandler() {
595  if (auto OldOneShotPipeFunction = OneShotPipeSignalFunction.exchange(nullptr))
596    OldOneShotPipeFunction();
597}
598
599/// Add a function to be called when a signal is delivered to the process. The
600/// handler can have a cookie passed to it to identify what instance of the
601/// handler it is.
602void llvm::sys::AddSignalHandler(sys::SignalHandlerCallback FnPtr,
603                                 void *Cookie) {
604  insertSignalHandler(FnPtr, Cookie);
605  RegisterHandler();
606  LeaveCriticalSection(&CriticalSection);
607}
608
609static void Cleanup(bool ExecuteSignalHandlers) {
610  if (CleanupExecuted)
611    return;
612
613  EnterCriticalSection(&CriticalSection);
614
615  // Prevent other thread from registering new files and directories for
616  // removal, should we be executing because of the console handler callback.
617  CleanupExecuted = true;
618
619  // FIXME: open files cannot be deleted.
620  if (FilesToRemove != NULL)
621    while (!FilesToRemove->empty()) {
622      llvm::sys::fs::remove(FilesToRemove->back());
623      FilesToRemove->pop_back();
624    }
625
626  if (ExecuteSignalHandlers)
627    llvm::sys::RunSignalHandlers();
628
629  LeaveCriticalSection(&CriticalSection);
630}
631
632void llvm::sys::RunInterruptHandlers() {
633  // The interrupt handler may be called from an interrupt, but it may also be
634  // called manually (such as the case of report_fatal_error with no registered
635  // error handler). We must ensure that the critical section is properly
636  // initialized.
637  InitializeThreading();
638  Cleanup(true);
639}
640
641/// Find the Windows Registry Key for a given location.
642///
643/// \returns a valid HKEY if the location exists, else NULL.
644static HKEY FindWERKey(const llvm::Twine &RegistryLocation) {
645  HKEY Key;
646  if (ERROR_SUCCESS != ::RegOpenKeyExA(HKEY_LOCAL_MACHINE,
647                                       RegistryLocation.str().c_str(), 0,
648                                       KEY_QUERY_VALUE | KEY_READ, &Key))
649    return NULL;
650
651  return Key;
652}
653
654/// Populate ResultDirectory with the value for "DumpFolder" for a given
655/// Windows Registry key.
656///
657/// \returns true if a valid value for DumpFolder exists, false otherwise.
658static bool GetDumpFolder(HKEY Key,
659                          llvm::SmallVectorImpl<char> &ResultDirectory) {
660  using llvm::sys::windows::UTF16ToUTF8;
661
662  if (!Key)
663    return false;
664
665  DWORD BufferLengthBytes = 0;
666
667  if (ERROR_SUCCESS != ::RegGetValueW(Key, 0, L"DumpFolder", REG_EXPAND_SZ,
668                                      NULL, NULL, &BufferLengthBytes))
669    return false;
670
671  SmallVector<wchar_t, MAX_PATH> Buffer(BufferLengthBytes);
672
673  if (ERROR_SUCCESS != ::RegGetValueW(Key, 0, L"DumpFolder", REG_EXPAND_SZ,
674                                      NULL, Buffer.data(), &BufferLengthBytes))
675    return false;
676
677  DWORD ExpandBufferSize = ::ExpandEnvironmentStringsW(Buffer.data(), NULL, 0);
678
679  if (!ExpandBufferSize)
680    return false;
681
682  SmallVector<wchar_t, MAX_PATH> ExpandBuffer(ExpandBufferSize);
683
684  if (ExpandBufferSize != ::ExpandEnvironmentStringsW(Buffer.data(),
685                                                      ExpandBuffer.data(),
686                                                      ExpandBufferSize))
687    return false;
688
689  if (UTF16ToUTF8(ExpandBuffer.data(), ExpandBufferSize - 1, ResultDirectory))
690    return false;
691
692  return true;
693}
694
695/// Populate ResultType with a valid MINIDUMP_TYPE based on the value of
696/// "DumpType" for a given Windows Registry key.
697///
698/// According to
699/// https://msdn.microsoft.com/en-us/library/windows/desktop/bb787181(v=vs.85).aspx
700/// valid values for DumpType are:
701///   * 0: Custom dump
702///   * 1: Mini dump
703///   * 2: Full dump
704/// If "Custom dump" is specified then the "CustomDumpFlags" field is read
705/// containing a bitwise combination of MINIDUMP_TYPE values.
706///
707/// \returns true if a valid value for ResultType can be set, false otherwise.
708static bool GetDumpType(HKEY Key, MINIDUMP_TYPE &ResultType) {
709  if (!Key)
710    return false;
711
712  DWORD DumpType;
713  DWORD TypeSize = sizeof(DumpType);
714  if (ERROR_SUCCESS != ::RegGetValueW(Key, NULL, L"DumpType", RRF_RT_REG_DWORD,
715                                      NULL, &DumpType, &TypeSize))
716    return false;
717
718  switch (DumpType) {
719  case 0: {
720    DWORD Flags = 0;
721    if (ERROR_SUCCESS != ::RegGetValueW(Key, NULL, L"CustomDumpFlags",
722                                        RRF_RT_REG_DWORD, NULL, &Flags,
723                                        &TypeSize))
724      return false;
725
726    ResultType = static_cast<MINIDUMP_TYPE>(Flags);
727    break;
728  }
729  case 1:
730    ResultType = MiniDumpNormal;
731    break;
732  case 2:
733    ResultType = MiniDumpWithFullMemory;
734    break;
735  default:
736    return false;
737  }
738  return true;
739}
740
741/// Write a Windows dump file containing process information that can be
742/// used for post-mortem debugging.
743///
744/// \returns zero error code if a mini dump created, actual error code
745/// otherwise.
746static std::error_code WINAPI
747WriteWindowsDumpFile(PMINIDUMP_EXCEPTION_INFORMATION ExceptionInfo) {
748  struct ScopedCriticalSection {
749    ScopedCriticalSection() { EnterCriticalSection(&CriticalSection); }
750    ~ScopedCriticalSection() { LeaveCriticalSection(&CriticalSection); }
751  } SCS;
752
753  using namespace llvm;
754  using namespace llvm::sys;
755
756  std::string MainExecutableName = fs::getMainExecutable(nullptr, nullptr);
757  StringRef ProgramName;
758
759  if (MainExecutableName.empty()) {
760    // If we can't get the executable filename,
761    // things are in worse shape than we realize
762    // and we should just bail out.
763    return mapWindowsError(::GetLastError());
764  }
765
766  ProgramName = path::filename(MainExecutableName.c_str());
767
768  // The Windows Registry location as specified at
769  // https://msdn.microsoft.com/en-us/library/windows/desktop/bb787181%28v=vs.85%29.aspx
770  // "Collecting User-Mode Dumps" that may optionally be set to collect crash
771  // dumps in a specified location.
772  StringRef LocalDumpsRegistryLocation =
773      "SOFTWARE\\Microsoft\\Windows\\Windows Error Reporting\\LocalDumps";
774
775  // The key pointing to the Registry location that may contain global crash
776  // dump settings.  This will be NULL if the location can not be found.
777  ScopedRegHandle DefaultLocalDumpsKey(FindWERKey(LocalDumpsRegistryLocation));
778
779  // The key pointing to the Registry location that may contain
780  // application-specific crash dump settings.  This will be NULL if the
781  // location can not be found.
782  ScopedRegHandle AppSpecificKey(
783      FindWERKey(Twine(LocalDumpsRegistryLocation) + "\\" + ProgramName));
784
785  // Look to see if a dump type is specified in the registry; first with the
786  // app-specific key and failing that with the global key.  If none are found
787  // default to a normal dump (GetDumpType will return false either if the key
788  // is NULL or if there is no valid DumpType value at its location).
789  MINIDUMP_TYPE DumpType;
790  if (!GetDumpType(AppSpecificKey, DumpType))
791    if (!GetDumpType(DefaultLocalDumpsKey, DumpType))
792      DumpType = MiniDumpNormal;
793
794  // Look to see if a dump location is specified on the command line.  If not,
795  // look to see if a dump location is specified in the registry; first with the
796  // app-specific key and failing that with the global key.  If none are found
797  // we'll just create the dump file in the default temporary file location
798  // (GetDumpFolder will return false either if the key is NULL or if there is
799  // no valid DumpFolder value at its location).
800  bool ExplicitDumpDirectorySet = true;
801  SmallString<MAX_PATH> DumpDirectory(*CrashDiagnosticsDirectory);
802  if (DumpDirectory.empty())
803    if (!GetDumpFolder(AppSpecificKey, DumpDirectory))
804      if (!GetDumpFolder(DefaultLocalDumpsKey, DumpDirectory))
805        ExplicitDumpDirectorySet = false;
806
807  int FD;
808  SmallString<MAX_PATH> DumpPath;
809
810  if (ExplicitDumpDirectorySet) {
811    if (std::error_code EC = fs::create_directories(DumpDirectory))
812      return EC;
813    if (std::error_code EC = fs::createUniqueFile(
814            Twine(DumpDirectory) + "\\" + ProgramName + ".%%%%%%.dmp", FD,
815            DumpPath))
816      return EC;
817  } else if (std::error_code EC =
818                 fs::createTemporaryFile(ProgramName, "dmp", FD, DumpPath))
819    return EC;
820
821  // Our support functions return a file descriptor but Windows wants a handle.
822  ScopedCommonHandle FileHandle(reinterpret_cast<HANDLE>(_get_osfhandle(FD)));
823
824  if (!fMiniDumpWriteDump(::GetCurrentProcess(), ::GetCurrentProcessId(),
825                          FileHandle, DumpType, ExceptionInfo, NULL, NULL))
826    return mapWindowsError(::GetLastError());
827
828  llvm::errs() << "Wrote crash dump file \"" << DumpPath << "\"\n";
829  return std::error_code();
830}
831
832void sys::CleanupOnSignal(uintptr_t Context) {
833  LPEXCEPTION_POINTERS EP = (LPEXCEPTION_POINTERS)Context;
834  // Broken pipe is not a crash.
835  //
836  // 0xE0000000 is combined with the return code in the exception raised in
837  // CrashRecoveryContext::HandleExit().
838  unsigned RetCode = EP->ExceptionRecord->ExceptionCode;
839  if (RetCode == (0xE0000000 | EX_IOERR))
840    return;
841  LLVMUnhandledExceptionFilter(EP);
842}
843
844static LONG WINAPI LLVMUnhandledExceptionFilter(LPEXCEPTION_POINTERS ep) {
845  Cleanup(true);
846
847  // Write out the exception code.
848  if (ep && ep->ExceptionRecord)
849    llvm::errs() << format("Exception Code: 0x%08X",
850                           ep->ExceptionRecord->ExceptionCode)
851                 << "\n";
852
853  // We'll automatically write a Minidump file here to help diagnose
854  // the nasty sorts of crashes that aren't 100% reproducible from a set of
855  // inputs (or in the event that the user is unable or unwilling to provide a
856  // reproducible case).
857  if (!llvm::sys::Process::AreCoreFilesPrevented()) {
858    MINIDUMP_EXCEPTION_INFORMATION ExceptionInfo;
859    ExceptionInfo.ThreadId = ::GetCurrentThreadId();
860    ExceptionInfo.ExceptionPointers = ep;
861    ExceptionInfo.ClientPointers = FALSE;
862
863    if (std::error_code EC = WriteWindowsDumpFile(&ExceptionInfo))
864      llvm::errs() << "Could not write crash dump file: " << EC.message()
865                   << "\n";
866  }
867
868  // Stack unwinding appears to modify the context. Copy it to preserve the
869  // caller's context.
870  CONTEXT ContextCopy;
871  if (ep)
872    memcpy(&ContextCopy, ep->ContextRecord, sizeof(ContextCopy));
873
874  LocalPrintStackTrace(llvm::errs(), ep ? &ContextCopy : nullptr);
875
876  return EXCEPTION_EXECUTE_HANDLER;
877}
878
879static BOOL WINAPI LLVMConsoleCtrlHandler(DWORD dwCtrlType) {
880  // We are running in our very own thread, courtesy of Windows.
881  EnterCriticalSection(&CriticalSection);
882  // This function is only ever called when a CTRL-C or similar control signal
883  // is fired. Killing a process in this way is normal, so don't trigger the
884  // signal handlers.
885  Cleanup(false);
886
887  // If an interrupt function has been set, go and run one it; otherwise,
888  // the process dies.
889  void (*IF)() = InterruptFunction;
890  InterruptFunction = 0; // Don't run it on another CTRL-C.
891
892  if (IF) {
893    // Note: if the interrupt function throws an exception, there is nothing
894    // to catch it in this thread so it will kill the process.
895    IF(); // Run it now.
896    LeaveCriticalSection(&CriticalSection);
897    return TRUE; // Don't kill the process.
898  }
899
900  // Allow normal processing to take place; i.e., the process dies.
901  LeaveCriticalSection(&CriticalSection);
902  return FALSE;
903}
904
905#if __MINGW32__
906// We turned these warnings off for this file so that MinGW-g++ doesn't
907// complain about the ll format specifiers used.  Now we are turning the
908// warnings back on.  If MinGW starts to support diagnostic stacks, we can
909// replace this with a pop.
910#pragma GCC diagnostic warning "-Wformat"
911#pragma GCC diagnostic warning "-Wformat-extra-args"
912#endif
913
914void sys::unregisterHandlers() {}
915