Native windows dll, proxy methods, Unsupported Dwarf2 information for...

[Stephen Crowley]

Hi,  I have a win32 dll which exports about 30 functions. I've used
winedump with the -f and -I flags to create stub/proxy functions which
use LoadLibrary.  Please CC my on all responses as I am not subscribed
to the list.

It generates functions like so..

HGTBSESSION __stdcall GTBAPI_gtbCreateSession(HWND hParent,
GTBSessionCallback * lpCallBack, void * lpParam)
{
        HGTBSESSION (__stdcall *pFunc)(HWND, const GTBSessionCallback
*, void *);
        HGTBSESSION retVal;
        pFunc=(void*)GetProcAddress(hDLL,"gtbCreateSession");
        TRACE("((HWND)%p,(GTBSessionCallback *)%p,(void *)%p):
forward\n",hParent,lpCallBack,lpParam);
        retVal = pFunc(hParent,lpCallBack,lpParam);
        TRACE("Returned (%p)\n",retVal);
        return retVal;
}

For compatibility with existing code I removed the GTBAPI_ from the
function and switched back to the native prototype.

GTAPIB_EXTERN HGTBSESSION WINAPI gtbCreateSession(HWND hParent, const
GTBSessionCallback *lpCallBack, void *lpParam)


Compiled and linked like so.

gcc -shared GTAPIB_main.c -I/usr/include/wine/windows
-I../GenSrc/API/GTAPIB -o ../lib/libgtapib.so
/usr/lib/wine/kernel32.dll.so


Then I have a small test app that I compile/link:

winegcc TestAPIB.c -I/usr/include/wine/windows -I
../../../GenSrc/API/GTAPIB -L../../../lib -lgtapib -lkernel32 -o
TestAPIB

Running ./TestAPIB throws the following error

WineDbg starting on pid 0x8
Unhandled exception: page fault on read access to 0x00000000 in 32-bit
code (0x00000000).
In 32 bit mode.
.....
Backtrace:
=>1 0x00000000 (0x406efe60)
fixme:dbghelp:elf_load_debug_info_from_map Unsupported Dwarf2
information for testapib<elf>
  2 0x405e5276 WinMain in testapib (0x406efe90)
  3 0x405e5173 __wine_exe_main in testapib (0x406eff20)
  4 0x404e0de2 in kernel32 (+0x50de2) (0x406efff4)
  5 0x4001d181 wine_switch_to_stack in libwine.so.1 (0x00000000)
0x00000000: addb        %al,0x0(%eax)

My wine version is 20050310

Any tips would be greatly appreciated.

Thanks,
Stephen

[Robert Shearman]

Stephen Crowley wrote:
> Hi,  I have a win32 dll which exports about 30 functions. I've used
> winedump with the -f and -I flags to create stub/proxy functions which
> use LoadLibrary.  Please CC my on all responses as I am not subscribed
> to the list.
>
> It generates functions like so..
>
> HGTBSESSION __stdcall GTBAPI_gtbCreateSession(HWND hParent,
> GTBSessionCallback * lpCallBack, void * lpParam)
> {
>        HGTBSESSION (__stdcall *pFunc)(HWND, const GTBSessionCallback
> *, void *);
>        HGTBSESSION retVal;
>        pFunc=(void*)GetProcAddress(hDLL,"gtbCreateSession");
>        TRACE("((HWND)%p,(GTBSessionCallback *)%p,(void *)%p):
> forward\n",hParent,lpCallBack,lpParam);
>        retVal = pFunc(hParent,lpCallBack,lpParam);
>        TRACE("Returned (%p)\n",retVal);
>        return retVal;
> }
>
> For compatibility with existing code I removed the GTBAPI_ from the
> function and switched back to the native prototype.
>
> GTAPIB_EXTERN HGTBSESSION WINAPI gtbCreateSession(HWND hParent, const
> GTBSessionCallback *lpCallBack, void *lpParam)
>
> Compiled and linked like so.
>
> gcc -shared GTAPIB_main.c -I/usr/include/wine/windows
> -I../GenSrc/API/GTAPIB -o ../lib/libgtapib.so
> /usr/lib/wine/kernel32.dll.so
>
> Then I have a small test app that I compile/link:
>
> winegcc TestAPIB.c -I/usr/include/wine/windows -I
> ../../../GenSrc/API/GTAPIB -L../../../lib -lgtapib -lkernel32 -o
> TestAPIB
>
> Running ./TestAPIB throws the following error
>
> WineDbg starting on pid 0x8
> Unhandled exception: page fault on read access to 0x00000000 in 32-bit
> code (0x00000000).
> In 32 bit mode.
> .....
> Backtrace:
> =>1 0x00000000 (0x406efe60)
> fixme:dbghelp:elf_load_debug_info_from_map Unsupported Dwarf2
> information for testapib<elf>
>  2 0x405e5276 WinMain in testapib (0x406efe90)
>  3 0x405e5173 __wine_exe_main in testapib (0x406eff20)
>  4 0x404e0de2 in kernel32 (+0x50de2) (0x406efff4)
>  5 0x4001d181 wine_switch_to_stack in libwine.so.1 (0x00000000)
> 0x00000000: addb        %al,0x0(%eax)
>
> My wine version is 20050310
>
> Any tips would be greatly appreciated.

Compile your program with the "-gstabs+" flag and you will get debugging 
information compatible with winedbg. From there, it should be easier to 
work out the real cause of the crash.

Rob