src/msw/stackwalk.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        msw/stackwalk.cpp
   3 // Purpose:     wxStackWalker implementation for Win32
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     2005-01-08
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2003-2005 Vadim Zeitlin <vadim@wxwindows.org>
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #include "wx/wxprec.h"
  21
  22 #ifdef __BORLANDC__
  23     #pragma hdrstop
  24 #endif
  25
  26 #if wxUSE_STACKWALKER
  27
  28 #ifndef WX_PRECOMP
  29     #include "wx/string.h"
  30 #endif
  31
  32 #include "wx/stackwalk.h"
  33
  34 #include "wx/msw/debughlp.h"
  35
  36 #if wxUSE_DBGHELP
  37
  38 // ============================================================================
  39 // implementation
  40 // ============================================================================
  41
  42 // ----------------------------------------------------------------------------
  43 // wxStackFrame
  44 // ----------------------------------------------------------------------------
  45
  46 void wxStackFrame::OnGetName()
  47 {
  48     if ( m_hasName )
  49         return;
  50
  51     m_hasName = true;
  52
  53     // get the name of the function for this stack frame entry
  54     static const size_t MAX_NAME_LEN = 1024;
  55     BYTE symbolBuffer[sizeof(SYMBOL_INFO) + MAX_NAME_LEN];
  56     wxZeroMemory(symbolBuffer);
  57
  58     PSYMBOL_INFO pSymbol = (PSYMBOL_INFO)symbolBuffer;
  59     pSymbol->SizeOfStruct = sizeof(symbolBuffer);
  60     pSymbol->MaxNameLen = MAX_NAME_LEN;
  61
  62     DWORD64 symDisplacement = 0;
  63     if ( !wxDbgHelpDLL::SymFromAddr
  64                         (
  65                             ::GetCurrentProcess(),
  66                             GetSymAddr(),
  67                             &symDisplacement,
  68                             pSymbol
  69                         ) )
  70     {
  71         wxDbgHelpDLL::LogError(_T("SymFromAddr"));
  72         return;
  73     }
  74
  75     m_name = wxString::FromAscii(pSymbol->Name);
  76     m_offset = symDisplacement;
  77 }
  78
  79 void wxStackFrame::OnGetLocation()
  80 {
  81     if ( m_hasLocation )
  82         return;
  83
  84     m_hasLocation = true;
  85
  86     // get the source line for this stack frame entry
  87     IMAGEHLP_LINE lineInfo = { sizeof(IMAGEHLP_LINE) };
  88     DWORD dwLineDisplacement;
  89     if ( !wxDbgHelpDLL::SymGetLineFromAddr
  90                         (
  91                             ::GetCurrentProcess(),
  92                             GetSymAddr(),
  93                             &dwLineDisplacement,
  94                             &lineInfo
  95                         ) )
  96     {
  97         // it is normal that we don't have source info for some symbols,
  98         // notably all the ones from the system DLLs...
  99         //wxDbgHelpDLL::LogError(_T("SymGetLineFromAddr"));
 100         return;
 101     }
 102
 103     m_filename = wxString::FromAscii(lineInfo.FileName);
 104     m_line = lineInfo.LineNumber;
 105 }
 106
 107 bool
 108 wxStackFrame::GetParam(size_t n,
 109                        wxString *type,
 110                        wxString *name,
 111                        wxString *value) const
 112 {
 113     if ( !DoGetParamCount() )
 114         ConstCast()->OnGetParam();
 115
 116     if ( n >= DoGetParamCount() )
 117         return false;
 118
 119     if ( type )
 120         *type = m_paramTypes[n];
 121     if ( name )
 122         *name = m_paramNames[n];
 123     if ( value )
 124         *value = m_paramValues[n];
 125
 126     return true;
 127 }
 128
 129 void wxStackFrame::OnParam(PSYMBOL_INFO pSymInfo)
 130 {
 131     m_paramTypes.Add(wxEmptyString);
 132
 133     m_paramNames.Add(wxString::FromAscii(pSymInfo->Name));
 134
 135     // if symbol information is corrupted and we crash, the exception is going
 136     // to be ignored when we're called from WalkFromException() because of the
 137     // exception handler there returning EXCEPTION_CONTINUE_EXECUTION, but we'd
 138     // be left in an inconsistent state, so deal with it explicitly here (even
 139     // if normally we should never crash, of course...)
 140 #ifdef _CPPUNWIND
 141     try
 142 #else
 143     __try
 144 #endif
 145     {
 146         // as it is a parameter (and not a global var), it is always offset by
 147         // the frame address
 148         DWORD_PTR pValue = m_addrFrame + pSymInfo->Address;
 149         m_paramValues.Add(wxDbgHelpDLL::DumpSymbol(pSymInfo, (void *)pValue));
 150     }
 151 #ifdef _CPPUNWIND
 152     catch ( ... )
 153 #else
 154     __except ( EXCEPTION_EXECUTE_HANDLER )
 155 #endif
 156     {
 157         m_paramValues.Add(wxEmptyString);
 158     }
 159 }
 160
 161 BOOL CALLBACK
 162 EnumSymbolsProc(PSYMBOL_INFO pSymInfo, ULONG WXUNUSED(SymSize), PVOID data)
 163 {
 164     wxStackFrame *frame = wx_static_cast(wxStackFrame *, data);
 165
 166     // we're only interested in parameters
 167     if ( pSymInfo->Flags & IMAGEHLP_SYMBOL_INFO_PARAMETER )
 168     {
 169         frame->OnParam(pSymInfo);
 170     }
 171
 172     // return true to continue enumeration, false would have stopped it
 173     return TRUE;
 174 }
 175
 176 void wxStackFrame::OnGetParam()
 177 {
 178     // use SymSetContext to get just the locals/params for this frame
 179     IMAGEHLP_STACK_FRAME imagehlpStackFrame;
 180     wxZeroMemory(imagehlpStackFrame);
 181     imagehlpStackFrame.InstructionOffset = GetSymAddr();
 182     if ( !wxDbgHelpDLL::SymSetContext
 183                         (
 184                             ::GetCurrentProcess(),
 185                             &imagehlpStackFrame,
 186                             0           // unused
 187                         ) )
 188     {
 189         // for symbols from kernel DLL we might not have access to their
 190         // address, this is not a real error
 191         if ( ::GetLastError() != ERROR_INVALID_ADDRESS )
 192         {
 193             wxDbgHelpDLL::LogError(_T("SymSetContext"));
 194         }
 195
 196         return;
 197     }
 198
 199     if ( !wxDbgHelpDLL::SymEnumSymbols
 200                         (
 201                             ::GetCurrentProcess(),
 202                             NULL,               // DLL base: use current context
 203                             NULL,               // no mask, get all symbols
 204                             EnumSymbolsProc,    // callback
 205                             this                // data to pass to it
 206                         ) )
 207     {
 208         wxDbgHelpDLL::LogError(_T("SymEnumSymbols"));
 209     }
 210 }
 211
 212
 213 // ----------------------------------------------------------------------------
 214 // wxStackWalker
 215 // ----------------------------------------------------------------------------
 216
 217 void wxStackWalker::WalkFrom(const CONTEXT *pCtx, size_t skip)
 218 {
 219     if ( !wxDbgHelpDLL::Init() )
 220     {
 221         // don't log a user-visible error message here because the stack trace
 222         // is only needed for debugging/diagnostics anyhow and we shouldn't
 223         // confuse the user by complaining that we couldn't generate it
 224         wxLogDebug(_T("Failed to get stack backtrace: %s"),
 225                    wxDbgHelpDLL::GetErrorMessage().c_str());
 226         return;
 227     }
 228
 229     // according to MSDN, the first parameter should be just a unique value and
 230     // not process handle (although the parameter is prototyped as "HANDLE
 231     // hProcess") and actually it advises to use the process id and not handle
 232     // for Win9x, but then we need to use the same value in StackWalk() call
 233     // below which should be a real handle... so this is what we use
 234     const HANDLE hProcess = ::GetCurrentProcess();
 235
 236     if ( !wxDbgHelpDLL::SymInitialize
 237                         (
 238                             hProcess,
 239                             NULL,   // use default symbol search path
 240                             TRUE    // load symbols for all loaded modules
 241                         ) )
 242     {
 243         wxDbgHelpDLL::LogError(_T("SymInitialize"));
 244
 245         return;
 246     }
 247
 248     CONTEXT ctx = *pCtx; // will be modified by StackWalk()
 249
 250     DWORD dwMachineType;
 251
 252     // initialize the initial frame: currently we can do it for x86 only
 253     STACKFRAME sf;
 254     wxZeroMemory(sf);
 255
 256 #ifdef _M_IX86
 257     sf.AddrPC.Offset       = ctx.Eip;
 258     sf.AddrPC.Mode         = AddrModeFlat;
 259     sf.AddrStack.Offset    = ctx.Esp;
 260     sf.AddrStack.Mode      = AddrModeFlat;
 261     sf.AddrFrame.Offset    = ctx.Ebp;
 262     sf.AddrFrame.Mode      = AddrModeFlat;
 263
 264     dwMachineType = IMAGE_FILE_MACHINE_I386;
 265 #else
 266     #error "Need to initialize STACKFRAME on non x86"
 267 #endif // _M_IX86
 268
 269     // iterate over all stack frames
 270     for ( size_t nLevel = 0; ; nLevel++ )
 271     {
 272         // get the next stack frame
 273         if ( !wxDbgHelpDLL::StackWalk
 274                             (
 275                                 dwMachineType,
 276                                 hProcess,
 277                                 ::GetCurrentThread(),
 278                                 &sf,
 279                                 &ctx,
 280                                 NULL,       // read memory function (default)
 281                                 wxDbgHelpDLL::SymFunctionTableAccess,
 282                                 wxDbgHelpDLL::SymGetModuleBase,
 283                                 NULL        // address translator for 16 bit
 284                             ) )
 285         {
 286             if ( ::GetLastError() )
 287                 wxDbgHelpDLL::LogError(_T("StackWalk"));
 288
 289             break;
 290         }
 291
 292         // don't show this frame itself in the output
 293         if ( nLevel >= skip )
 294         {
 295             wxStackFrame frame(nLevel - skip,
 296                                (void *)sf.AddrPC.Offset,
 297                                sf.AddrFrame.Offset);
 298
 299             OnStackFrame(frame);
 300         }
 301     }
 302
 303     // this results in crashes inside ntdll.dll when called from
 304     // exception handler ...
 305 #if 0
 306     if ( !wxDbgHelpDLL::SymCleanup(hProcess) )
 307     {
 308         wxDbgHelpDLL::LogError(_T("SymCleanup"));
 309     }
 310 #endif
 311 }
 312
 313 void wxStackWalker::WalkFrom(const _EXCEPTION_POINTERS *ep, size_t skip)
 314 {
 315     WalkFrom(ep->ContextRecord, skip);
 316 }
 317
 318 void wxStackWalker::WalkFromException()
 319 {
 320     extern EXCEPTION_POINTERS *wxGlobalSEInformation;
 321
 322     wxCHECK_RET( wxGlobalSEInformation,
 323                  _T("wxStackWalker::WalkFromException() can only be called from wxApp::OnFatalException()") );
 324
 325     // don't skip any frames, the first one is where we crashed
 326     WalkFrom(wxGlobalSEInformation, 0);
 327 }
 328
 329 void wxStackWalker::Walk(size_t skip)
 330 {
 331     // to get a CONTEXT for the current location, simply force an exception and
 332     // get EXCEPTION_POINTERS from it
 333     //
 334     // note:
 335     //  1. we additionally skip RaiseException() and WalkFromException() frames
 336     //  2. explicit cast to EXCEPTION_POINTERS is needed with VC7.1 even if it
 337     //     shouldn't have been according to the docs
 338     __try
 339     {
 340         RaiseException(0x1976, 0, 0, NULL);
 341     }
 342     __except( WalkFrom((EXCEPTION_POINTERS *)GetExceptionInformation(),
 343                        skip + 2), EXCEPTION_CONTINUE_EXECUTION )
 344     {
 345         // never executed because of WalkFromException() return value
 346     }
 347 }
 348
 349 #else // !wxUSE_DBGHELP
 350
 351 // ============================================================================
 352 // stubs
 353 // ============================================================================
 354
 355 // ----------------------------------------------------------------------------
 356 // wxStackFrame
 357 // ----------------------------------------------------------------------------
 358
 359 void wxStackFrame::OnGetName()
 360 {
 361 }
 362
 363 void wxStackFrame::OnGetLocation()
 364 {
 365 }
 366
 367 bool
 368 wxStackFrame::GetParam(size_t WXUNUSED(n),
 369                        wxString * WXUNUSED(type),
 370                        wxString * WXUNUSED(name),
 371                        wxString * WXUNUSED(value)) const
 372 {
 373     return false;
 374 }
 375
 376 void wxStackFrame::OnParam(_SYMBOL_INFO * WXUNUSED(pSymInfo))
 377 {
 378 }
 379
 380 void wxStackFrame::OnGetParam()
 381 {
 382 }
 383
 384 // ----------------------------------------------------------------------------
 385 // wxStackWalker
 386 // ----------------------------------------------------------------------------
 387
 388 void
 389 wxStackWalker::WalkFrom(const CONTEXT * WXUNUSED(pCtx), size_t WXUNUSED(skip))
 390 {
 391 }
 392
 393 void
 394 wxStackWalker::WalkFrom(const _EXCEPTION_POINTERS * WXUNUSED(ep),
 395                         size_t WXUNUSED(skip))
 396 {
 397 }
 398
 399 void wxStackWalker::WalkFromException()
 400 {
 401 }
 402
 403 void wxStackWalker::Walk(size_t WXUNUSED(skip))
 404 {
 405 }
 406
 407 #endif // wxUSE_DBGHELP/!wxUSE_DBGHELP
 408
 409 #endif // wxUSE_STACKWALKER
 410