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(_T(""));
 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     // except handler there returning EXCEPTION_CONTINUE_EXECUTION, but we'd be
 138     // left in an inconsistent state, so deal with it explicitely here (even if
 139     // 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(_T(""));
 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         wxLogError(_("Failed to get stack backtrace:\n%s"),
 222                    wxDbgHelpDLL::GetErrorMessage().c_str());
 223     }
 224
 225     // according to MSDN, the first parameter should be just a unique value and
 226     // not process handle (although the parameter is prototyped as "HANDLE
 227     // hProcess") and actually it advises to use the process id and not handle
 228     // for Win9x, but then we need to use the same value in StackWalk() call
 229     // below which should be a real handle... so this is what we use
 230     const HANDLE hProcess = ::GetCurrentProcess();
 231
 232     if ( !wxDbgHelpDLL::SymInitialize
 233                         (
 234                             hProcess,
 235                             NULL,   // use default symbol search path
 236                             TRUE    // load symbols for all loaded modules
 237                         ) )
 238     {
 239         wxDbgHelpDLL::LogError(_T("SymInitialize"));
 240
 241         return;
 242     }
 243
 244     CONTEXT ctx = *pCtx; // will be modified by StackWalk()
 245
 246     DWORD dwMachineType;
 247
 248     // initialize the initial frame: currently we can do it for x86 only
 249     STACKFRAME sf;
 250     wxZeroMemory(sf);
 251
 252 #ifdef _M_IX86
 253     sf.AddrPC.Offset       = ctx.Eip;
 254     sf.AddrPC.Mode         = AddrModeFlat;
 255     sf.AddrStack.Offset    = ctx.Esp;
 256     sf.AddrStack.Mode      = AddrModeFlat;
 257     sf.AddrFrame.Offset    = ctx.Ebp;
 258     sf.AddrFrame.Mode      = AddrModeFlat;
 259
 260     dwMachineType = IMAGE_FILE_MACHINE_I386;
 261 #else
 262     #error "Need to initialize STACKFRAME on non x86"
 263 #endif // _M_IX86
 264
 265     // iterate over all stack frames
 266     for ( size_t nLevel = 0; ; nLevel++ )
 267     {
 268         // get the next stack frame
 269         if ( !wxDbgHelpDLL::StackWalk
 270                             (
 271                                 dwMachineType,
 272                                 hProcess,
 273                                 ::GetCurrentThread(),
 274                                 &sf,
 275                                 &ctx,
 276                                 NULL,       // read memory function (default)
 277                                 wxDbgHelpDLL::SymFunctionTableAccess,
 278                                 wxDbgHelpDLL::SymGetModuleBase,
 279                                 NULL        // address translator for 16 bit
 280                             ) )
 281         {
 282             if ( ::GetLastError() )
 283                 wxDbgHelpDLL::LogError(_T("StackWalk"));
 284
 285             break;
 286         }
 287
 288         // don't show this frame itself in the output
 289         if ( nLevel >= skip )
 290         {
 291             wxStackFrame frame(nLevel - skip,
 292                                (void *)sf.AddrPC.Offset,
 293                                sf.AddrFrame.Offset);
 294
 295             OnStackFrame(frame);
 296         }
 297     }
 298
 299     // this results in crashes inside ntdll.dll when called from
 300     // exception handler ...
 301 #if 0
 302     if ( !wxDbgHelpDLL::SymCleanup(hProcess) )
 303     {
 304         wxDbgHelpDLL::LogError(_T("SymCleanup"));
 305     }
 306 #endif
 307 }
 308
 309 void wxStackWalker::WalkFrom(const _EXCEPTION_POINTERS *ep, size_t skip)
 310 {
 311     WalkFrom(ep->ContextRecord, skip);
 312 }
 313
 314 void wxStackWalker::WalkFromException()
 315 {
 316     extern EXCEPTION_POINTERS *wxGlobalSEInformation;
 317
 318     wxCHECK_RET( wxGlobalSEInformation,
 319                  _T("wxStackWalker::WalkFromException() can only be called from wxApp::OnFatalException()") );
 320
 321     // don't skip any frames, the first one is where we crashed
 322     WalkFrom(wxGlobalSEInformation, 0);
 323 }
 324
 325 void wxStackWalker::Walk(size_t skip)
 326 {
 327     // to get a CONTEXT for the current location, simply force an exception and
 328     // get EXCEPTION_POINTERS from it
 329     //
 330     // note:
 331     //  1. we additionally skip RaiseException() and WalkFromException() frames
 332     //  2. explicit cast to EXCEPTION_POINTERS is needed with VC7.1 even if it
 333     //     shouldn't have been according to the docs
 334     __try
 335     {
 336         RaiseException(0x1976, 0, 0, NULL);
 337     }
 338     __except( WalkFrom((EXCEPTION_POINTERS *)GetExceptionInformation(),
 339                        skip + 2), EXCEPTION_CONTINUE_EXECUTION )
 340     {
 341         // never executed because of WalkFromException() return value
 342     }
 343 }
 344
 345 #else // !wxUSE_DBGHELP
 346
 347 // TODO: implement stubs
 348
 349 #endif // wxUSE_DBGHELP/!wxUSE_DBGHELP
 350
 351 #endif // wxUSE_STACKWALKER
 352