OpenEuphoria

Re: ECW weird behavior

• Posted by Robert Craig <rds at RapidEuphoria.com> Oct 19, 2005
• 492 views

André Drummond wrote:
> 
> Robert Craig wrote:
> > 
> > André Drummond wrote:
> > > I´m using the GD library to create some gif images, and it seems not to
> > > work
> > > when the program is translated to C (then compiled with Borland).
> > > 
> > > The following function (from GD wrapper gd.e) could only work after I
> > > introduced
> > > the "if 1 then end if" statement below:
> > > }}}
<eucode>
> > > global function gdImageCreateFromGif(sequence fd)
> > > atom lpfd, ret, str, mode, oldmode
> > > 	if equal(fd, GD_FILE_STDIO) then
> > > 		if platform() = 2 then
> > > 			oldmode = c_func(setmode, {0, #8000})
> > > 		end if
> > > 		mode = allocate_string("rb")
> > > 		lpfd = c_func(fdopen, {0, mode})
> > > 	else
> > > 		str = allocate_string(fd)
> > > 		mode = allocate_string("rb")
> > > 		lpfd = c_func(fopen, {str, mode})
> > > 		free(str)
> > > 	end if
> > > 	free(mode)
> > > 	if lpfd = 0 then
> > > 		return 0
> > > 	end if
> > > 	ret = c_func(GdImageCreateFromGif, {lpfd})
> > > 	str = c_func(fclose, {lpfd})
> > > 
> > > 	-- Look Here!!!	
> > > 	if 1 then	end if
> > > 	--
> > > 
> > > 	if equal(fd, GD_FILE_STDIO) and platform() = 2 then
> > > 		oldmode = c_func(setmode, {0, oldmode})
> > > 	end if
> > > 	return ret
> > > end function
> > > </eucode>
{{{

> > >  
> > > The same thing happens with this other procedure (also in gd.e):
> > > 
> > > }}}
<eucode>
> > > global procedure gdImageGif(gdImagePtr im, sequence out)
> > > 	atom lpfd, str, mode, oldmode
> > > 	if equal(out, GD_FILE_STDIO) then
> > > 		if platform() = 2 then
> > > 			oldmode = c_func(setmode, {1, #8000})
> > > 		end if
> > > 		mode = allocate_string("wb")
> > > 		lpfd = c_func(fdopen, {1, mode})
> > > 	else
> > > 		str = allocate_string(out)
> > > 		mode = allocate_string("wb")
> > > 		lpfd = c_func(fopen, {str, mode})
> > > 		free(str)
> > > 	end if
> > > 	free(mode)
> > > 	if lpfd = 0 then
> > > 		return
> > > 	end if
> > > 	c_proc(GdImageGif, {im, lpfd})
> > > 	str = c_func(fclose, {lpfd})
> > > 
> > > 	-- Look Here!!!	
> > > 	if 1 then	end if
> > > 	--
> > > 
> > > 	if equal(out, GD_FILE_STDIO) and platform() = 2 then
> > > 		oldmode = c_func(setmode, {1, oldmode})
> > > 	end if
> > > end procedure
> > > </eucode>
{{{

> > > If I run the program with exw it works fine, but if I translate it them is
> > > doesn´t
> > > work... I narrow down the bug to those two pieces of code presented. By
> > > bebugging
> > > it I see that any usual command before the "Look Here!!!" points leads to
> > > an
> > > machine error.
> > > 
> > > Then, I desperately try to introduce the dummy line "if 1 then end if" and
> > > see
> > > what happens then, for my surprise, it started to work.
> > > 
> > > Does anyone have a clue of whats happening?
> > 
> > The author of gd.e apparently forgot to specify the CDECL calling
> > convention in his define_c_func()/proc() statements. Most .dlls, other
> > than those written by Microsoft as part of the WIN32 API, use CDECL.
> > In most cases, the Euphoria interpreter will handle 
> > CDECL correctly, even when it's declared incorrectly as STDCALL 
> > (the default). It will also work if you translate to C and compile 
> > with WATCOM. The error doesn't show up until you translate and 
> > compile with Borland (or Lcc).
> > 
> > The solution is to add a "+" sign to all the define_c_func/proc
> > calls that you depend on. e.g. in gd.e:
> >   GdImageCreateFromGif = define_c_func(GD_LIB, "gdImageCreateFromGif", ...
> > becomes:
> >   GdImageCreateFromGif = define_c_func(GD_LIB, "+gdImageCreateFromGif", ...
> > 
> > Also fclose() etc.
> > 
> > You should let the author know about it.
> > 
> > Regards,
> >    Rob Craig
> >    Rapid Deployment Software
> >    <a href="http://www.RapidEuphoria.com">http://www.RapidEuphoria.com</a>
> > 
> 
> Hi Robert,
> 
> I´ve put "+"s in all define_c_func and define_c_proc the way you've said. But
> the problem stills persists.
> 
> Now, I am out of tricks... what else can we try?

Did you add "+"'s on *all* the routines that you are using,
e.g. fopen, fdopen, setmode etc.? Basically anything that
isn't in Microsoft's WIN32 API.

Regards,
   Rob Craig
   Rapid Deployment Software
   http://www.RapidEuphoria.com