Add comments explaining the workaround for mingw 3.2.3

[wxWidgets.git] / src / msw / main.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        msw/main.cpp
// Purpose:     WinMain/DllMain
// Author:      Julian Smart
// Modified by:
// Created:     04/01/98
// RCS-ID:      $Id$
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

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

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

#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
    #pragma implementation
#endif

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

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#include "wx/event.h"
#include "wx/app.h"
#include "wx/cmdline.h"

#include "wx/msw/private.h"

#if wxUSE_ON_FATAL_EXCEPTION
    #include "wx/datetime.h"
    #include "wx/msw/crashrpt.h"

    #ifdef __VISUALC__
        #include <eh.h>
    #endif // __VISUALC__
#endif // wxUSE_ON_FATAL_EXCEPTION

#ifdef __WXWINCE__
    // there is no ExitProcess() under CE but exiting the main thread has the
    // same effect
    #ifndef ExitProcess
        #define ExitProcess ExitThread
    #endif
#endif // __WXWINCE__

#ifdef __BORLANDC__
    // BC++ has to be special: its run-time expects the DLL entry point to be
    // named DllEntryPoint instead of the (more) standard DllMain
    #define DllMain DllEntryPoint
#endif // __BORLANDC__

#if defined(__WXMICROWIN__)
    #define HINSTANCE HANDLE
#endif

// defined in common/init.cpp
extern int wxEntryReal(int& argc, wxChar **argv);

// ============================================================================
// implementation: various entry points
// ============================================================================

#if wxUSE_BASE

#if wxUSE_ON_FATAL_EXCEPTION && defined(__VISUALC__) && !defined(__WXWINCE__)
    // VC++ (at least from 4.0 up to version 7.1) is incredibly broken in that
    // a "catch ( ... )" will *always* catch SEH exceptions in it even though
    // it should have never been the case... to prevent such catches from
    // stealing the exceptions from our wxGlobalSEHandler which is only called
    // if the exception is not handled elsewhere, we have to also call it from
    // a special SEH translator function which is called by VC CRT when a Win32
    // exception occurs

    // this warns that /EHa (async exceptions) should be used when using
    // _set_se_translator but, in fact, this doesn't seem to change anything
    // with VC++ up to 7.1 -- to be confirmed with VC++ 8
    #if _MSC_VER <= 1310
        #pragma warning(disable:4535)
    #endif

    // note that the SE translator must be called wxSETranslator!
    #define DisableAutomaticSETranslator() _set_se_translator(wxSETranslator)
#else // !__VISUALC__
    #define DisableAutomaticSETranslator()
#endif // __VISUALC__/!__VISUALC__

// ----------------------------------------------------------------------------
// wrapper wxEntry catching all Win32 exceptions occuring in a wx program
// ----------------------------------------------------------------------------

// wrap real wxEntry in a try-except block to be able to call
// OnFatalException() if necessary
#if wxUSE_ON_FATAL_EXCEPTION

// global pointer to exception information, only valid inside OnFatalException,
// used by wxStackWalker and wxCrashReport
extern EXCEPTION_POINTERS *wxGlobalSEInformation = NULL;

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

static void wxFatalExit()
{
    // use the same exit code as abort()
    ::ExitProcess(3);
}

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;
}

#ifdef __VISUALC__

static void wxSETranslator(unsigned int WXUNUSED(code), EXCEPTION_POINTERS *ep)
{
    switch ( wxGlobalSEHandler(ep) )
    {
        default:
            wxFAIL_MSG( _T("unexpected wxGlobalSEHandler() return value") );
            // fall through

        case EXCEPTION_EXECUTE_HANDLER:
            // if wxApp::OnFatalException() had been called we should exit the
            // application -- but we shouldn't kill our host when we're a DLL
#ifndef WXMAKINGDLL
            wxFatalExit();
#endif // not a DLL
            break;

        case EXCEPTION_CONTINUE_SEARCH:
            // we're called for each "catch ( ... )" and if we (re)throw from
            // here, the catch handler body is not executed, so the effect is
            // as if had inhibited translation of SE to C++ ones because the
            // handler will never see any structured exceptions
            throw;
    }
}

#endif // __VISUALC__

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

#if wxUSE_CRASHREPORT
    if ( doit )
    {
        // try to find a place where we can put out report file later
        wxChar fullname[MAX_PATH];
        if ( !::GetTempPath(WXSIZEOF(fullname), fullname) )
        {
            wxLogLastError(_T("GetTempPath"));

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

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

        wxStrncat(fullname, name, WXSIZEOF(fullname) - wxStrlen(fullname) - 1);

        wxCrashReport::SetFileName(fullname);
    }
#endif // wxUSE_CRASHREPORT

    return true;
}

int wxEntry(int& argc, wxChar **argv)
{
    DisableAutomaticSETranslator();

    __try
    {
        return wxEntryReal(argc, argv);
    }
    __except ( wxGlobalSEHandler(GetExceptionInformation()) )
    {
        wxFatalExit();

        // this code is unreachable but put it here to suppress warnings
        return -1;
    }
}

#else // !wxUSE_ON_FATAL_EXCEPTION

#if defined(__VISUALC__) && !defined(__WXWINCE__)

static void
wxSETranslator(unsigned int WXUNUSED(code), EXCEPTION_POINTERS * WXUNUSED(ep))
{
    // see wxSETranslator() version for wxUSE_ON_FATAL_EXCEPTION above
    throw;
}

#endif // __VISUALC__

int wxEntry(int& argc, wxChar **argv)
{
    DisableAutomaticSETranslator();

    return wxEntryReal(argc, argv);
}

#endif // wxUSE_ON_FATAL_EXCEPTION/!wxUSE_ON_FATAL_EXCEPTION

#endif // wxUSE_BASE

#if wxUSE_GUI

// ----------------------------------------------------------------------------
// Windows-specific wxEntry
// ----------------------------------------------------------------------------

WXDLLEXPORT int wxEntry(HINSTANCE hInstance,
                        HINSTANCE WXUNUSED(hPrevInstance),
                        wxCmdLineArgType WXUNUSED(pCmdLine),
                        int nCmdShow)
{
    // remember the parameters Windows gave us
    wxSetInstance(hInstance);
    wxApp::m_nCmdShow = nCmdShow;

    // parse the command line: we can't use pCmdLine in Unicode build so it is
    // simpler to never use it at all (this also results in a more correct
    // argv[0])

    // break the command line in words
    wxArrayString args;

    const wxChar *cmdLine = ::GetCommandLine();
    if ( cmdLine )
    {
        args = wxCmdLineParser::ConvertStringToArgs(cmdLine);
    }

#ifdef __WXWINCE__
    // WinCE doesn't insert the program itself, so do it ourselves.
    args.Insert(wxGetFullModuleName(), 0);
#endif

    int argc = args.GetCount();

    // +1 here for the terminating NULL
    wxChar **argv = new wxChar *[argc + 1];
    for ( int i = 0; i < argc; i++ )
    {
        argv[i] = wxStrdup(args[i]);
    }

    // argv[] must be NULL-terminated
    argv[argc] = NULL;

    return wxEntry(argc, argv);
}

// May wish not to have a DllMain or WinMain, e.g. if we're programming
// a Netscape plugin or if we're writing a console application
#if !defined(NOMAIN)

extern "C"
{

// ----------------------------------------------------------------------------
// WinMain
// ----------------------------------------------------------------------------

// Note that WinMain is also defined in dummy.obj, which is linked to
// an application that is using the DLL version of wxWidgets.

#if defined(_WINDLL)

// DLL entry point

BOOL WINAPI
DllMain(HINSTANCE hModule, DWORD fdwReason, LPVOID WXUNUSED(lpReserved))
{
    // Only call wxEntry if the application itself is part of the DLL.
    // If only the wxWidgets library is in the DLL, then the
    // initialisation will be called when the application implicitly
    // calls WinMain.
#ifndef WXMAKINGDLL
    switch (fdwReason)
    {
        case DLL_PROCESS_ATTACH:
            return wxEntry(hModule);

        case DLL_PROCESS_DETACH:
            wxEntryCleanup();
            break;
    }
#else
    (void)hModule;
    (void)fdwReason;
#endif // !WXMAKINGDLL

    return TRUE;
}

#endif // _WINDLL

} // extern "C"

#endif // !NOMAIN

#endif // wxUSE_GUI

// ----------------------------------------------------------------------------
// global HINSTANCE
// ----------------------------------------------------------------------------

#if wxUSE_BASE

HINSTANCE wxhInstance = 0;

extern "C" HINSTANCE wxGetInstance()
{
    return wxhInstance;
}

void wxSetInstance(HINSTANCE hInst)
{
    wxhInstance = hInst;
}

#endif // wxUSE_BASE