src/msw/crashrpt.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        msw/crashrpt.cpp
// Purpose:     helpers for structured exception handling (SEH)
// Author:      Vadim Zeitlin
// Modified by:
// Created:     13.07.03
// RCS-ID:      $Id$
// Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

/*
    The code in this file is heavily based on Matt Pietrek's column from
    the March 2002 issue of MSDN Magazine.
 */

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#if wxUSE_ON_FATAL_EXCEPTION

#ifndef WX_PRECOMP
#endif  //WX_PRECOMP

#include "wx/longlong.h"
#include "wx/datetime.h"
#include "wx/dynload.h"

#include "wx/msw/crashrpt.h"

#include "wx/msw/wrapwin.h"
#include <imagehlp.h>
#include "wx/msw/private.h"

// we need to determine whether we have the declarations for the function in
// debughlp.dll version 5.81 (at least) and we check for DBHLPAPI to test this
//
// reasons:
//  - VC6 version of imagehlp.h doesn't define it
//  - VC7 one does
//  - testing for compiler version doesn't work as you can install and use
//    the new SDK headers with VC6
//
// in any case, the user may override by defining wxUSE_DBGHELP himself
#ifndef wxUSE_DBGHELP
    #ifdef DBHLPAPI
        #define wxUSE_DBGHELP 1
    #else
        #define wxUSE_DBGHELP 0
    #endif
#endif

#if wxUSE_DBGHELP

// ----------------------------------------------------------------------------
// types of imagehlp.h functions
// ----------------------------------------------------------------------------

typedef DWORD (WINAPI *SymSetOptions_t)(DWORD);
typedef BOOL (WINAPI *SymInitialize_t)(HANDLE, LPSTR, BOOL);
typedef BOOL (WINAPI *StackWalk_t)(DWORD, HANDLE, HANDLE, LPSTACKFRAME,
                                   LPVOID, PREAD_PROCESS_MEMORY_ROUTINE,
                                   PFUNCTION_TABLE_ACCESS_ROUTINE,
                                   PGET_MODULE_BASE_ROUTINE,
                                   PTRANSLATE_ADDRESS_ROUTINE);
typedef BOOL (WINAPI *SymFromAddr_t)(HANDLE, DWORD64, PDWORD64, PSYMBOL_INFO);
typedef LPVOID (WINAPI *SymFunctionTableAccess_t)(HANDLE, DWORD);
typedef DWORD (WINAPI *SymGetModuleBase_t)(HANDLE, DWORD);
typedef BOOL (WINAPI *SymGetLineFromAddr_t)(HANDLE, DWORD,
                                            PDWORD, PIMAGEHLP_LINE);
typedef BOOL (WINAPI *SymSetContext_t)(HANDLE, PIMAGEHLP_STACK_FRAME,
                                       PIMAGEHLP_CONTEXT);
typedef BOOL (WINAPI *SymEnumSymbols_t)(HANDLE, ULONG64, PCSTR,
                                        PSYM_ENUMERATESYMBOLS_CALLBACK, PVOID);
typedef BOOL (WINAPI *SymGetTypeInfo_t)(HANDLE, DWORD64, ULONG,
                                        IMAGEHLP_SYMBOL_TYPE_INFO, PVOID);

// ----------------------------------------------------------------------------
// constant
// ----------------------------------------------------------------------------

// Stolen from CVCONST.H in the DIA 2.0 SDK
enum BasicType
{
    BASICTYPE_NOTYPE = 0,
    BASICTYPE_VOID = 1,
    BASICTYPE_CHAR = 2,
    BASICTYPE_WCHAR = 3,
    BASICTYPE_INT = 6,
    BASICTYPE_UINT = 7,
    BASICTYPE_FLOAT = 8,
    BASICTYPE_BCD = 9,
    BASICTYPE_BOOL = 10,
    BASICTYPE_LONG = 13,
    BASICTYPE_ULONG = 14,
    BASICTYPE_CURRENCY = 25,
    BASICTYPE_DATE = 26,
    BASICTYPE_VARIANT = 27,
    BASICTYPE_COMPLEX = 28,
    BASICTYPE_BIT = 29,
    BASICTYPE_BSTR = 30,
    BASICTYPE_HRESULT = 31
};

// Same as above
enum SymbolTag
{
    SYMBOL_TAG_NULL,
    SYMBOL_TAG_FUNCTION = 5,
    SYMBOL_TAG_DATA = 7,
    SYMBOL_TAG_PUBLIC = 10,             // appears in .DBGs
    SYMBOL_TAG_UDT,
    SYMBOL_TAG_ENUM,
    SYMBOL_TAG_FUNCTION_TYPE,
    SYMBOL_TAG_POINTER_TYPE,
    SYMBOL_TAG_ARRAY_TYPE,
    SYMBOL_TAG_BASE_TYPE,
    SYMBOL_TAG_TYPEDEF,
    SYMBOL_TAG_BASECLASS
};

#endif // wxUSE_DBGHELP

// ----------------------------------------------------------------------------
// classes
// ----------------------------------------------------------------------------

// the real crash report generator
class wxCrashReportImpl
{
public:
    wxCrashReportImpl(const wxChar *filename);

    bool Generate(int flags);

    ~wxCrashReportImpl()
    {
        if ( m_hFile != INVALID_HANDLE_VALUE )
        {
            ::CloseHandle(m_hFile);
        }
    }

private:
    // formatted output to m_hFile
    void Output(const wxChar *format, ...);

    // output end of line
    void OutputEndl() { Output(_T("\r\n")); }

#if wxUSE_DBGHELP
    // translate exception code to its symbolic name
    static wxString GetExceptionString(DWORD dwCode);

    // return the type from "type index"
    static BasicType GetBasicType(DWORD64 modBase, DWORD typeIndex);

    // return the name for the type index
    static wxString GetSymbolName(DWORD64 modBase, DWORD dwTypeIndex);

    // return the string representation of the variable value
    static wxString FormatSimpleValue(BasicType bt,
                                      DWORD64 length,
                                      PVOID pAddress);

    // return string representation of a struct field (which may itself be a
    // struct, of course)
    static wxString FormatField(DWORD64 modBase,
                                DWORD dwTypeIndex,
                                void *pVariable,
                                unsigned level);

    // show the name and value of the given symbol
    static wxString FormatSymbol(PSYMBOL_INFO pSym, STACKFRAME *sf);

    // show value described by SYMBOL_INFO located at pVariable
    static wxString FormatAnyValue(PSYMBOL_INFO pSym, void *pVariable);

    // show value of possibly complex (user-defined) type
    static wxString FormatUDT(DWORD64 modBase,
                              DWORD dwTypeIndex,
                              void *pVariable,
                              unsigned level = 0);

    // outputs information about the given symbol
    void OutputSymbol(PSYMBOL_INFO pSymInfo, STACKFRAME *sf);

    // load all the functions we need from dbghelp.dll, return true if all ok
    bool ResolveSymFunctions(const wxDynamicLibrary& dllDbgHelp);

    // map address to module (and also section:offset), retunr true if ok
    static bool GetLogicalAddress(PVOID addr,
                                  PTSTR szModule,
                                  DWORD len,
                                  DWORD& section,
                                  DWORD& offset);

    // callback used with SymEnumSymbols() to process all variables
    static BOOL CALLBACK EnumerateSymbolsCallback(PSYMBOL_INFO  pSymInfo,
                                                  ULONG         SymbolSize,
                                                  PVOID         UserContext);


    // show the general information about exception which should be always
    // available
    //
    // returns the module of the handle where the crash occured
    HANDLE OutputBasicContext(EXCEPTION_RECORD *pExceptionRecord, CONTEXT *pCtx);

    // output the call stack and local variables values
    void OutputStack(const CONTEXT *pCtx, int flags);

    // output the global variables values
    void OutputGlobals(HANDLE hModuleCrash);


    // the current stack frame (may be NULL)
    STACKFRAME *m_sfCurrent;


    // dynamically loaded dbghelp.dll functions
    #define DECLARE_SYM_FUNCTION(func) static func ## _t func

    DECLARE_SYM_FUNCTION(SymSetOptions);
    DECLARE_SYM_FUNCTION(SymInitialize);
    DECLARE_SYM_FUNCTION(StackWalk);
    DECLARE_SYM_FUNCTION(SymFromAddr);
    DECLARE_SYM_FUNCTION(SymFunctionTableAccess);
    DECLARE_SYM_FUNCTION(SymGetModuleBase);
    DECLARE_SYM_FUNCTION(SymGetLineFromAddr);
    DECLARE_SYM_FUNCTION(SymSetContext);
    DECLARE_SYM_FUNCTION(SymEnumSymbols);
    DECLARE_SYM_FUNCTION(SymGetTypeInfo);
#endif // wxUSE_DBGHELP

    // the handle of the report file
    HANDLE m_hFile;
};

// ----------------------------------------------------------------------------
// globals
// ----------------------------------------------------------------------------

// global pointer to exception information, only valid inside OnFatalException
extern WXDLLIMPEXP_BASE EXCEPTION_POINTERS *wxGlobalSEInformation = NULL;


// flag telling us whether the application wants to handle exceptions at all
static bool gs_handleExceptions = false;

// the file name where the report about exception is written
static wxChar gs_reportFilename[MAX_PATH];

// ============================================================================
// implementation
// ============================================================================

#if wxUSE_DBGHELP

#define DEFINE_SYM_FUNCTION(func) func ## _t wxCrashReportImpl::func = 0

DEFINE_SYM_FUNCTION(SymSetOptions);
DEFINE_SYM_FUNCTION(SymInitialize);
DEFINE_SYM_FUNCTION(StackWalk);
DEFINE_SYM_FUNCTION(SymFromAddr);
DEFINE_SYM_FUNCTION(SymFunctionTableAccess);
DEFINE_SYM_FUNCTION(SymGetModuleBase);
DEFINE_SYM_FUNCTION(SymGetLineFromAddr);
DEFINE_SYM_FUNCTION(SymSetContext);
DEFINE_SYM_FUNCTION(SymEnumSymbols);
DEFINE_SYM_FUNCTION(SymGetTypeInfo);

#undef DEFINE_SYM_FUNCTION

#endif // wxUSE_DBGHELP

// ----------------------------------------------------------------------------
// wxCrashReportImpl
// ----------------------------------------------------------------------------

wxCrashReportImpl::wxCrashReportImpl(const wxChar *filename)
{
#if wxUSE_DBGHELP
    m_sfCurrent = NULL;
#endif // wxUSE_DBGHELP

    m_hFile = ::CreateFile
                (
                    filename,
                    GENERIC_WRITE,
                    0,                          // no sharing
                    NULL,                       // default security
                    CREATE_ALWAYS,
                    FILE_FLAG_WRITE_THROUGH,
                    NULL                        // no template file
                );
}

void wxCrashReportImpl::Output(const wxChar *format, ...)
{
    va_list argptr;
    va_start(argptr, format);

    DWORD cbWritten;

    wxString s = wxString::FormatV(format, argptr);
    ::WriteFile(m_hFile, s, s.length() * sizeof(wxChar), &cbWritten, 0);

    va_end(argptr);
}

#if wxUSE_DBGHELP

bool
wxCrashReportImpl::GetLogicalAddress(PVOID addr,
                                     PTSTR szModule,
                                     DWORD len,
                                     DWORD& section,
                                     DWORD& offset)
{
    MEMORY_BASIC_INFORMATION mbi;

    if ( !::VirtualQuery(addr, &mbi, sizeof(mbi)) )
        return false;

    DWORD hMod = (DWORD)mbi.AllocationBase;

    if ( !::GetModuleFileName((HMODULE)hMod, szModule, len) )
        return false;

    // Point to the DOS header in memory
    PIMAGE_DOS_HEADER pDosHdr = (PIMAGE_DOS_HEADER)hMod;

    // From the DOS header, find the NT (PE) header
    PIMAGE_NT_HEADERS pNtHdr = (PIMAGE_NT_HEADERS)(hMod + pDosHdr->e_lfanew);

    PIMAGE_SECTION_HEADER pSection = IMAGE_FIRST_SECTION( pNtHdr );

    DWORD rva = (DWORD)addr - hMod; // RVA is offset from module load address

    // Iterate through the section table, looking for the one that encompasses
    // the linear address.
    const DWORD nSections = pNtHdr->FileHeader.NumberOfSections;
    for ( DWORD i = 0; i < nSections; i++, pSection++ )
    {
        DWORD sectionStart = pSection->VirtualAddress;
        DWORD sectionEnd = sectionStart
                    + max(pSection->SizeOfRawData, pSection->Misc.VirtualSize);

        // Is the address in this section?
        if ( (rva >= sectionStart) && (rva <= sectionEnd) )
        {
            // Yes, address is in the section.  Calculate section and offset,
            // and store in the "section" & "offset" params, which were
            // passed by reference.
            section = i + 1;
            offset = rva - sectionStart;

            return true;
        }
    }

    // failed to map to logical address...
    return false;
}

/* static */ BasicType
wxCrashReportImpl::GetBasicType(DWORD64 modBase, DWORD typeIndex)
{
    const HANDLE hProcess = GetCurrentProcess();

    // try the index we have
    BasicType bt;
    if ( SymGetTypeInfo(hProcess, modBase, typeIndex, TI_GET_BASETYPE, &bt) )
    {
        return bt;
    }

    // if failed, try to get the "real" typeid first
    DWORD typeId;
    if ( SymGetTypeInfo(hProcess, modBase, typeIndex, TI_GET_TYPEID, &typeId)
            &&
         (typeId != typeIndex &&
            SymGetTypeInfo(hProcess, modBase, typeId, TI_GET_BASETYPE, &bt)) )
    {
        return bt;
    }

    return BASICTYPE_NOTYPE;
}

/* static */ wxString
wxCrashReportImpl::FormatSimpleValue(BasicType bt,
                                     DWORD64 length,
                                     PVOID pAddress)
{
    wxString s;
    s.reserve(256);

    // Format appropriately (assuming it's a 1, 2, or 4 bytes (!!!)
    if ( length == 1 )
    {
        s.Printf(_T("%#04x"), *(PBYTE)pAddress);
    }
    else if ( length == 2 )
    {
        s.Printf(_T("%#06x"), *(PWORD)pAddress);
    }
    else if ( length == 4 )
    {
        bool handled = false;

        if ( bt == BASICTYPE_FLOAT )
        {
            s.Printf(_T("%f"), *(PFLOAT)pAddress);

            handled = true;
        }
        else if ( bt == BASICTYPE_CHAR )
        {
            static const size_t NUM_CHARS = 32;

            const char * const pc = *(PSTR *)pAddress;
            if ( !::IsBadStringPtrA(pc, NUM_CHARS) )
            {
                s << _T('"') << wxString(pc, wxConvLibc, NUM_CHARS) << _T('"');

                handled = true;
            }
        }

        if ( !handled )
        {
            // treat just as an opaque DWORD
            s.Printf(_T("%#x"), *(PDWORD)pAddress);
        }
    }
    else if ( length == 8 )
    {
        if ( bt == BASICTYPE_FLOAT )
        {
            s.Printf(_T("%lf"), *(double *)pAddress);
        }
        else // opaque 64 bit value
        {
            s.Printf(_T("%#" wxLongLongFmtSpec _T("x")), *(PDWORD *)pAddress);
        }
    }

    return s;
}

/* static */
wxString wxCrashReportImpl::GetSymbolName(DWORD64 modBase, DWORD dwTypeIndex)
{
    wxString s;

    WCHAR *pwszTypeName;
    if ( SymGetTypeInfo
         (
            GetCurrentProcess(),
            modBase,
            dwTypeIndex,
            TI_GET_SYMNAME,
            &pwszTypeName
         ) )
    {
        s = wxConvCurrent->cWC2WX(pwszTypeName);

        ::LocalFree(pwszTypeName);
    }

    return s;
}

// this is called for the struct members/base classes
wxString
wxCrashReportImpl::FormatField(DWORD64 modBase,
                               DWORD dwTypeIndex,
                               void *pVariable,
                               unsigned level)
{
    wxString s;

    // avoid infinite recursion
    if ( level > 10 )
    {
        return s;
    }

    const HANDLE hProcess = GetCurrentProcess();

    DWORD dwTag = 0;
    SymGetTypeInfo(hProcess, modBase, dwTypeIndex, TI_GET_SYMTAG, &dwTag);

    switch ( dwTag )
    {
        case SYMBOL_TAG_UDT:
        case SYMBOL_TAG_BASECLASS:
            s = FormatUDT(modBase, dwTypeIndex, pVariable, level);
            break;

        case SYMBOL_TAG_FUNCTION:
            // don't show
            break;

        default:
            // try to treat all the rest as data even though it's not clear if
            // it's really a good idea...

            // Get the offset of the child member, relative to its parent
            DWORD dwMemberOffset = 0;
            SymGetTypeInfo(hProcess, modBase, dwTypeIndex,
                           TI_GET_OFFSET, &dwMemberOffset);

            // Get the real "TypeId" of the child.  We need this for the
            // SymGetTypeInfo(TI_GET_LENGTH) call below.
            DWORD typeId;
            if ( !SymGetTypeInfo(hProcess, modBase, dwTypeIndex,
                                 TI_GET_TYPEID, &typeId) )
            {
                typeId = dwTypeIndex;
            }

            // Get the size of the child member
            ULONG64 size;
            SymGetTypeInfo(hProcess, modBase, typeId, TI_GET_LENGTH, &size);

            // Calculate the address of the member
            DWORD_PTR dwFinalOffset = (DWORD_PTR)pVariable + dwMemberOffset;

            BasicType basicType = GetBasicType(modBase, dwTypeIndex);

            s = FormatSimpleValue(basicType, size, (PVOID)dwFinalOffset);
            break;

    }

    if ( s.empty() )
    {
        // don't show if no value -- what for?
        return s;
    }

    return wxString(_T('\t'), level + 1) +
                GetSymbolName(modBase, dwTypeIndex) +
                    _T(" = ") + s + _T("\r\n");
}

// If it's a user defined type (UDT), recurse through its members until we're
// at fundamental types.
wxString
wxCrashReportImpl::FormatUDT(DWORD64 modBase,
                             DWORD dwTypeIndex,
                             void *pVariable,
                             unsigned level)
{
    wxString s;
    s.reserve(512);
    s = GetSymbolName(modBase, dwTypeIndex) + _T(" {\r\n");

    const HANDLE hProcess = GetCurrentProcess();

    // Determine how many children this type has.
    DWORD dwChildrenCount = 0;
    SymGetTypeInfo(hProcess, modBase, dwTypeIndex, TI_GET_CHILDRENCOUNT,
                   &dwChildrenCount);

    // Prepare to get an array of "TypeIds", representing each of the children.
    TI_FINDCHILDREN_PARAMS *children = (TI_FINDCHILDREN_PARAMS *)
        malloc(sizeof(TI_FINDCHILDREN_PARAMS) +
                    (dwChildrenCount - 1)*sizeof(ULONG));
    if ( !children )
        return s;

    children->Count = dwChildrenCount;
    children->Start = 0;

    // Get the array of TypeIds, one for each child type
    if ( !SymGetTypeInfo(hProcess, modBase, dwTypeIndex, TI_FINDCHILDREN,
                         children) )
    {
        return s;
    }

    // Iterate through all children
    for ( unsigned i = 0; i < dwChildrenCount; i++ )
    {
        s += FormatField(modBase, children->ChildId[i], pVariable, level + 1);
    }

    free(children);

    s << wxString(_T('\t'), level + 1) << _T('}');

    return s;
}

// return the string containing the symbol of the given symbol
/* static */ wxString
wxCrashReportImpl::FormatAnyValue(PSYMBOL_INFO pSym, void *pVariable)
{
    DWORD dwTag = 0;
    SymGetTypeInfo(GetCurrentProcess(), pSym->ModBase, pSym->TypeIndex,
                   TI_GET_SYMTAG, &dwTag);

    wxString s;
    switch ( dwTag )
    {
        case SYMBOL_TAG_FUNCTION:
            break;

        case SYMBOL_TAG_UDT:
        case SYMBOL_TAG_BASECLASS:
            // show UDT recursively
            s = FormatUDT(pSym->ModBase, pSym->TypeIndex, pVariable);
            break;

        default:
            // variable of simple type (but could be array which we don't
            // handle correctly yet...), format it using its type and size
            BasicType bt = GetBasicType(pSym->ModBase, pSym->TypeIndex);

            s = FormatSimpleValue(bt, pSym->Size, pVariable);
            break;

    }

    return s;
}

// display contents and type of the given variable
/* static */ wxString
wxCrashReportImpl::FormatSymbol(PSYMBOL_INFO pSym, STACKFRAME *sf)
{
    wxString s;

    if ( pSym->Tag == SYMBOL_TAG_FUNCTION )
    {
        // If it's a function, don't do anything.
        return s;
    }

    if ( pSym->Flags & IMAGEHLP_SYMBOL_INFO_REGISTER )
    {
        // Don't try to report register variable
        return s;
    }

    s.reserve(512);

    // Indicate if the variable is a local or parameter
    if ( pSym->Flags & IMAGEHLP_SYMBOL_INFO_PARAMETER )
        s += _T("\t[param] ");
    else if ( pSym->Flags & IMAGEHLP_SYMBOL_INFO_LOCAL )
        s += _T("\t[local] ");

    // Will point to the variable's data in memory
    DWORD_PTR pVariable = 0;

    if ( (pSym->Flags & IMAGEHLP_SYMBOL_INFO_REGRELATIVE) && sf )
    {
        pVariable = sf->AddrFrame.Offset;
        pVariable += (DWORD_PTR)pSym->Address;
    }
    else // It must be a global variable
    {
        pVariable = (DWORD_PTR)pSym->Address;
    }

    s << wxString(pSym->Name, wxConvLibc)
      << _T(" = ")
      << FormatAnyValue(pSym, (PVOID)pVariable);

    return s;
}

void
wxCrashReportImpl::OutputSymbol(PSYMBOL_INFO pSymInfo, STACKFRAME  *sf)
{
    wxString s = FormatSymbol(pSymInfo, sf);
    if ( !s.empty() )
    {
        Output(_T("%s\r\n"), s.c_str());
    }
    //else: not an interesting symbol
}

// callback for SymEnumSymbols()
/* static */
BOOL CALLBACK
wxCrashReportImpl::EnumerateSymbolsCallback(PSYMBOL_INFO  pSymInfo,
                                            ULONG         WXUNUSED(SymbolSize),
                                            PVOID         UserContext)
{
    wxCrashReportImpl *self = (wxCrashReportImpl *)UserContext;

    __try
    {
        self->OutputSymbol(pSymInfo, self->m_sfCurrent);
    }
    __except ( EXCEPTION_EXECUTE_HANDLER )
    {
        self->Output(_T("Can't process symbol %hs\r\n"), pSymInfo->Name);
    }

    // continue with enumeration
    return true;
}

HANDLE
wxCrashReportImpl::OutputBasicContext(EXCEPTION_RECORD *pExceptionRecord,
                                    CONTEXT *pCtx)
{
    // First print information about the type of fault
    const DWORD dwCode = pExceptionRecord->ExceptionCode;
    Output(_T("Exception code: %s (%#10x)\r\n"),
           GetExceptionString(dwCode).c_str(), dwCode);

    // Now print information about where the fault occured
    TCHAR szFaultingModule[MAX_PATH];
    DWORD section,
          offset;
    void * const pExceptionAddress = pExceptionRecord->ExceptionAddress;
    if ( !GetLogicalAddress(pExceptionAddress,
                            szFaultingModule,
                            WXSIZEOF(szFaultingModule),
                            section, offset) )
    {
        section =
        offset = 0;

        wxStrcpy(szFaultingModule, _T("<< unknown >>"));
    }

    Output(_T("Fault address:  %08x %02x:%08x %s\r\n"),
           pExceptionAddress, section, offset, szFaultingModule);

#ifdef _M_IX86
    // Show the registers
    Output( _T("\r\nRegisters:\r\n") );

    Output(_T("EAX: %08x EBX: %08x ECX: %08x EDX: %08x ESI: %08x EDI: %08x\r\n"),
            pCtx->Eax, pCtx->Ebx, pCtx->Ecx, pCtx->Edx, pCtx->Esi, pCtx->Edi);

    Output(_T("CS:EIP: %04x:%08x SS:ESP: %04x:%08x  EBP: %08x\r\n"),
           pCtx->SegCs, pCtx->Eip, pCtx->SegSs, pCtx->Esp, pCtx->Ebp );
    Output(_T("DS: %04x  ES: %04x  FS: %04x  GS: %04x\r\n"),
           pCtx->SegDs, pCtx->SegEs, pCtx->SegFs, pCtx->SegGs);
    Output(_T("Flags: %08x\r\n"), pCtx->EFlags );
#endif // _M_IX86

    return ::GetModuleHandle(szFaultingModule);
}

void wxCrashReportImpl::OutputStack(const CONTEXT *pCtx, int flags)
{
    enum
    {
        Output_Stack,
        Output_Locals,
        Output_Max
#ifndef _M_IX86
        // can't show locals under other architectures
            = Output_Locals
#endif
    };

    for ( int step = 0; step < Output_Max; step++ )
    {
        // don't do things we're not asked for
        if ( (step == Output_Stack) && !(flags & wxCRASH_REPORT_STACK) ||
                (step == Output_Locals) && !(flags & wxCRASH_REPORT_LOCALS) )
        {
            continue;
        }

        // the context is going to be modified below so make a copy
        CONTEXT ctx = *pCtx;

        Output(_T("\r\n%s\r\n")
               _T(" # Address   Frame     Function            SourceFile\r\n"),
               step == Output_Stack ? _T("Call stack") : _T("Local variables"));

        DWORD dwMachineType = 0;

        STACKFRAME sf;
        wxZeroMemory(sf);

#ifdef _M_IX86
        // Initialize the STACKFRAME structure for the first call.  This is
        // only necessary for Intel CPUs, and isn't mentioned in the
        // documentation.
        sf.AddrPC.Offset       = ctx.Eip;
        sf.AddrPC.Mode         = AddrModeFlat;
        sf.AddrStack.Offset    = ctx.Esp;
        sf.AddrStack.Mode      = AddrModeFlat;
        sf.AddrFrame.Offset    = ctx.Ebp;
        sf.AddrFrame.Mode      = AddrModeFlat;

        dwMachineType = IMAGE_FILE_MACHINE_I386;
#endif // _M_IX86

        const HANDLE hProcess = GetCurrentProcess();
        const HANDLE hThread = GetCurrentThread();

        // first show just the call stack
        int frame = 0;
        for ( ;; )
        {
            // Get the next stack frame
            if ( !StackWalk(dwMachineType,
                            hProcess,
                            hThread,
                            &sf,
                            &ctx,
                            0,
                            SymFunctionTableAccess,
                            SymGetModuleBase,
                            0) )
            {
                break;
            }

            // Basic sanity check to make sure the frame is OK.
            if ( !sf.AddrFrame.Offset )
                break;

            Output(_T("%2d %08x  %08x  "),
                   frame++, sf.AddrPC.Offset, sf.AddrFrame.Offset);

            // Get the name of the function for this stack frame entry
            BYTE symbolBuffer[ sizeof(SYMBOL_INFO) + 1024 ];
            PSYMBOL_INFO pSymbol = (PSYMBOL_INFO)symbolBuffer;
            pSymbol->SizeOfStruct = sizeof(symbolBuffer);
            pSymbol->MaxNameLen = 1024;

            // Displacement of the input address, relative to the start of the
            // symbol
            DWORD64 symDisplacement = 0;

            if ( SymFromAddr(hProcess, sf.AddrPC.Offset,
                             &symDisplacement,pSymbol) )
            {
                Output(_T("%hs()+%#") wxLongLongFmtSpec _T("x"),
                       pSymbol->Name, symDisplacement);
            }
            else    // No symbol found.  Print out the logical address instead.
            {
                TCHAR szModule[MAX_PATH];
                DWORD section,
                      offset;

                if ( !GetLogicalAddress((PVOID)sf.AddrPC.Offset,
                                        szModule, sizeof(szModule),
                                        section, offset) )
                {
                    szModule[0] = _T('\0');
                    section =
                    offset = 0;
                }

                Output(_T("%04x:%08x %s"), section, offset, szModule);
            }

            // Get the source line for this stack frame entry
            IMAGEHLP_LINE lineInfo = { sizeof(IMAGEHLP_LINE) };
            DWORD dwLineDisplacement;
            if ( SymGetLineFromAddr(hProcess, sf.AddrPC.Offset,
                                    &dwLineDisplacement, &lineInfo ))
            {
                Output(_T("  %s line %u"),
                       lineInfo.FileName, lineInfo.LineNumber);
            }

            OutputEndl();


#ifdef _M_IX86
            // on the second iteration also show the local variables and
            // parameters
            if ( step == Output_Locals )
            {
                // Use SymSetContext to get just the locals/params for this
                // frame
                IMAGEHLP_STACK_FRAME imagehlpStackFrame;
                imagehlpStackFrame.InstructionOffset = sf.AddrPC.Offset;
                SymSetContext(hProcess, &imagehlpStackFrame, 0);

                // Enumerate the locals/parameters
                m_sfCurrent = &sf;
                SymEnumSymbols(hProcess, 0, 0, EnumerateSymbolsCallback, this);

                OutputEndl();
            }
#endif // _M_IX86
        }
    }
}

void wxCrashReportImpl::OutputGlobals(HANDLE hModule)
{
#ifdef _M_IX86
    Output(_T("\r\nGlobal variables:\r\n"));

    m_sfCurrent = NULL;
    SymEnumSymbols(::GetCurrentProcess(), (DWORD64)hModule, NULL,
                   EnumerateSymbolsCallback, this);
#endif // _M_IX86
}

bool wxCrashReportImpl::ResolveSymFunctions(const wxDynamicLibrary& dllDbgHelp)
{
    #define LOAD_SYM_FUNCTION(name)                                           \
        name = (name ## _t) dllDbgHelp.GetSymbol(_T(#name));                  \
        if ( !name )                                                          \
        {                                                                     \
            Output(_T("\r\nFunction ") _T(#name)                              \
                   _T("() not found.\r\n"));                                  \
            return false;                                                     \
        }

    LOAD_SYM_FUNCTION(SymSetOptions);
    LOAD_SYM_FUNCTION(SymInitialize);
    LOAD_SYM_FUNCTION(StackWalk);
    LOAD_SYM_FUNCTION(SymFromAddr);
    LOAD_SYM_FUNCTION(SymFunctionTableAccess);
    LOAD_SYM_FUNCTION(SymGetModuleBase);
    LOAD_SYM_FUNCTION(SymGetLineFromAddr);
    LOAD_SYM_FUNCTION(SymSetContext);
    LOAD_SYM_FUNCTION(SymEnumSymbols);
    LOAD_SYM_FUNCTION(SymGetTypeInfo);

    #undef LOAD_SYM_FUNCTION

    return true;
}

/* static */
wxString wxCrashReportImpl::GetExceptionString(DWORD dwCode)
{
    wxString s;

    #define CASE_EXCEPTION( x ) case EXCEPTION_##x: s = _T(#x); break

    switch ( dwCode )
    {
        CASE_EXCEPTION(ACCESS_VIOLATION);
        CASE_EXCEPTION(DATATYPE_MISALIGNMENT);
        CASE_EXCEPTION(BREAKPOINT);
        CASE_EXCEPTION(SINGLE_STEP);
        CASE_EXCEPTION(ARRAY_BOUNDS_EXCEEDED);
        CASE_EXCEPTION(FLT_DENORMAL_OPERAND);
        CASE_EXCEPTION(FLT_DIVIDE_BY_ZERO);
        CASE_EXCEPTION(FLT_INEXACT_RESULT);
        CASE_EXCEPTION(FLT_INVALID_OPERATION);
        CASE_EXCEPTION(FLT_OVERFLOW);
        CASE_EXCEPTION(FLT_STACK_CHECK);
        CASE_EXCEPTION(FLT_UNDERFLOW);
        CASE_EXCEPTION(INT_DIVIDE_BY_ZERO);
        CASE_EXCEPTION(INT_OVERFLOW);
        CASE_EXCEPTION(PRIV_INSTRUCTION);
        CASE_EXCEPTION(IN_PAGE_ERROR);
        CASE_EXCEPTION(ILLEGAL_INSTRUCTION);
        CASE_EXCEPTION(NONCONTINUABLE_EXCEPTION);
        CASE_EXCEPTION(STACK_OVERFLOW);
        CASE_EXCEPTION(INVALID_DISPOSITION);
        CASE_EXCEPTION(GUARD_PAGE);
        CASE_EXCEPTION(INVALID_HANDLE);

        default:
            // unknown exception, ask NTDLL for the name
            if ( !::FormatMessage
                    (
                     FORMAT_MESSAGE_IGNORE_INSERTS |
                     FORMAT_MESSAGE_FROM_HMODULE,
                     ::GetModuleHandle(_T("NTDLL.DLL")),
                     dwCode,
                     0,
                     wxStringBuffer(s, 1024),
                     1024,
                     0
                    ) )
            {
                s = _T("UNKNOWN_EXCEPTION");
            }
    }

    #undef CASE_EXCEPTION

    return s;
}

#endif // wxUSE_DBGHELP

// Remove warning
#if wxUSE_DBGHELP
#define _WXUNUSED(x) x
#else
#define _WXUNUSED WXUNUSED
#endif

bool wxCrashReportImpl::Generate(int _WXUNUSED(flags))
{
    if ( m_hFile == INVALID_HANDLE_VALUE )
        return false;

#if wxUSE_DBGHELP
    if ( !wxGlobalSEInformation )
        return false;

    PEXCEPTION_RECORD pExceptionRecord = wxGlobalSEInformation->ExceptionRecord;
    PCONTEXT pCtx = wxGlobalSEInformation->ContextRecord;

    if ( !pExceptionRecord || !pCtx )
        return false;

    HANDLE hModuleCrash = OutputBasicContext(pExceptionRecord, pCtx);

    // for everything else we need dbghelp.dll
    wxDynamicLibrary dllDbgHelp(_T("dbghelp.dll"), wxDL_VERBATIM);
    if ( dllDbgHelp.IsLoaded() )
    {
        if ( ResolveSymFunctions(dllDbgHelp) )
        {
            SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME);

            // Initialize DbgHelp
            if ( SymInitialize(GetCurrentProcess(), NULL, TRUE /* invade */) )
            {
                OutputStack(pCtx, flags);

                if ( hModuleCrash && (flags & wxCRASH_REPORT_GLOBALS) )
                {
                    OutputGlobals(hModuleCrash);
                }

                return true;
            }
        }
        else
        {
            Output(_T("Please update your dbghelp.dll version, ")
                   _T("at least version 5.1 is needed!\r\n"));
        }
    }
    else
    {
        Output(_T("Please install dbghelp.dll available free of charge ")
               _T("from Microsoft to get more detailed crash information!"));
    }

    Output(_T("\r\nLatest dbghelp.dll is available at ")
           _T("http://www.microsoft.com/whdc/ddk/debugging/\r\n"));

#else // !wxUSE_DBGHELP
    Output(_T("Support for crash report generation was not included ")
           _T("in this wxWindows version."));
#endif // wxUSE_DBGHELP/!wxUSE_DBGHELP

    return true;
}

// ----------------------------------------------------------------------------
// wxCrashReport
// ----------------------------------------------------------------------------

/* static */
void wxCrashReport::SetFileName(const wxChar *filename)
{
    wxStrncpy(gs_reportFilename, filename, WXSIZEOF(gs_reportFilename) - 1);
    gs_reportFilename[WXSIZEOF(gs_reportFilename) - 1] = _T('\0');
}

/* static */
const wxChar *wxCrashReport::GetFileName()
{
    return gs_reportFilename;
}

/* static */
bool wxCrashReport::Generate(int flags)
{
    wxCrashReportImpl impl(gs_reportFilename);

    return impl.Generate(flags);
}

// ----------------------------------------------------------------------------
// wxApp::OnFatalException() support
// ----------------------------------------------------------------------------

bool wxHandleFatalExceptions(bool doit)
{
    // assume this can only be called from the main thread
    gs_handleExceptions = doit;

    if ( doit )
    {
        // try to find a place where we can put out report file later
        if ( !::GetTempPath
                (
                    WXSIZEOF(gs_reportFilename),
                    gs_reportFilename
                ) )
        {
            wxLogLastError(_T("GetTempPath"));

            // when all else fails...
            wxStrcpy(gs_reportFilename, _T("c:\\"));
        }

        // use PID and date to make the report file name more unique
        wxString fname = wxString::Format
                         (
                            _T("%s_%s_%lu.rpt"),
                            wxTheApp ? wxTheApp->GetAppName().c_str()
                                     : _T("wxwindows"),
                            wxDateTime::Now().Format(_T("%Y%m%d")).c_str(),
                            ::GetCurrentProcessId()
                         );

        wxStrncat(gs_reportFilename, fname,
                  WXSIZEOF(gs_reportFilename) - wxStrlen(gs_reportFilename) - 1);
    }

    return true;
}

extern unsigned long wxGlobalSEHandler(EXCEPTION_POINTERS *pExcPtrs)
{
    if ( gs_handleExceptions && wxTheApp )
    {
        // store the pointer to exception info
        wxGlobalSEInformation = pExcPtrs;

        // give the user a chance to do something special about this
        __try
        {
            wxTheApp->OnFatalException();
        }
        __except ( EXCEPTION_EXECUTE_HANDLER )
        {
            // nothing to do here, just ignore the exception inside the
            // exception handler
            ;
        }

        wxGlobalSEInformation = NULL;

        // this will execute our handler and terminate the process
        return EXCEPTION_EXECUTE_HANDLER;
    }

    return EXCEPTION_CONTINUE_SEARCH;
}

#else // !wxUSE_ON_FATAL_EXCEPTION

bool wxHandleFatalExceptions(bool WXUNUSED(doit))
{
    wxFAIL_MSG(_T("set wxUSE_ON_FATAL_EXCEPTION to 1 to use this function"));

    return false;
}

#endif // wxUSE_ON_FATAL_EXCEPTION/!wxUSE_ON_FATAL_EXCEPTION