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