[GSLL-devel] grid, foreign-array, fsbv and libffi

[Sumant Oemrawsingh]

Hi Liam,

Thanks for your answer. I am using quicklisp as well under windows, so
I have fsbv installed, and that is when I noticed the problems
concerning libffi under windows. While trying to fix the issues, I
noticed that it was more intricate than I expected.

Integrating fsbv into cffi would indeed be an elegant solution. And I
understand that libffi is required for by-value calls; thanks for the
explanation. I never realised that this can't be done with the (lisp
implementation dependent) ffi. I just assumed it was only a matter of
wrapping those functions into cffi.

Anyway, thanks again. I'll get the new fsbv and try to get
foreign-array working under windows. And maybe with some effort and
the miracle of christmas, I can manage to get fsbv working _with_
libffi under windows!

-Sumant

On Tue, Nov 30, 2010 at 12:38:41PM -0500, Liam Healy wrote:
> Yes.
> 
> I'm in the process of changing FSBV (and GSLL, and to some extent GSD)
> with two intertwined goals.  One goal is to have all foreign struct
> interface handled in one place, so that e.g. complex-double-c (in GSD)
> and sf-result (in GSLL) are handled the same way.  Since this is (for
> now) being done in FSBV, it has the effect of splitting FSBV into two
> parts, say "FS" (foreign structures) and "FSBV" (foreign structures by
> value).   The first part will handle conversions between foreign and
> CL objects, as with #'object and #'(setf object).  It happens that GSD
> defines complex foreign types but call functions with those arguments
> by value; GSLL optionally uses them by value.
> 
> The second goal is a long-term one of integrating FSBV into CFFI.
> When I do that, the part that just addresses foreign structures (not
> by-value calls) will (I'm hoping) be loaded automatically.   Then,
> foreign-array will only require CFFI (which it already does).  The "by
> value" part will be an optional system for CFFI users,  because it
> requires libffi.
> 
> I hope the explanation is clear.  To answer your specific question:
> I've pushed a new version of FSBV; in that version, you only have to
> load pkgdcl.lisp and convert.lisp, and you won't need libffi.  Sorry
> for the awkward state; for the time being FSBV is mandatory, but I'm
> hoping that goes away in the not-too-distant future.  I didn't make a
> separate branch because it does work as-is, and I figured most people
> were getting these systems via quicklisp, which already installs the
> entire FSBV.
> 
> Liam
> 
> On Tue, Nov 30, 2010 at 11:58 AM, Sumant Oemrawsingh <soemraws at xs4all.nl> wrote:
> > Hi Liam,
> >
> > Recently, I tried getting foreign-array working on windows (with
> > sbcl). I noticed that foreign-array uses fsbv (apparently) and fsbv
> > uses libffi. I haven't dug around in the code yet, but I was wondering
> > if you have a quick explanation why libffi is used, and why cffi is
> > not sufficient. The reason I ask is because I'm wondering if it would
> > be possible to hack it under windows so it doesn't need libffi (which
> > apparently is quite difficult to get working there).
> >
> > Thanks,
> > Sumant
> >
> > _______________________________________________
> > GSLL-devel mailing list
> > GSLL-devel at common-lisp.net
> > http://common-lisp.net/cgi-bin/mailman/listinfo/gsll-devel
> >
> 
> _______________________________________________
> GSLL-devel mailing list
> GSLL-devel at common-lisp.net
> http://common-lisp.net/cgi-bin/mailman/listinfo/gsll-devel