February 2006 - cffi-devel - mailman3.common-lisp.net

[cffi-devel] Problem with SDL_Init using CFFI with Clisp in Windows 98
by Jeremy Smith 01 Feb '06

01 Feb '06

Hi, I'm posting this to the CFFI discussion group, I previously posted it to the Lisp Application Builder list. Anyway, the L/AB people have made an SDL module that lets CFFI-supported Lisps use SDL (it's a very portable gaming library). I use Clisp exclusively, so I wanted to see SDL work properly with it, just so I can develop my application using it. At first I wrote my own SDL header module using ah2cl.lisp, but later I came across the L/AB module, and used that instead. What I'm getting to is, I read on comp.lang.lisp that the CFFI-based SDL module does not work on Windows 98 under Clisp. I just tested it on my Windows 98 laptop (P166 :-) and it says the same thing. "FFI: FOREIGN-LIBRARY-FUNCTION: No dynamic object named 'SDL_Init' in library :DEFAULT" My hack that uses FFI (not CFFI) to run SDL works fine on Windows 98, so the issue is definitely part of CFFI. I did a little bit of detective work: Clisp's top-level view shows the scope, at the time of the above error as (from src/cffi-clisp.lisp): `(funcall (load-time-value (ffi::foreign-library-function ,name (ffi::foreign-library :default) nil (ffi:parse-c-type ',ctype))) ,@fargs)))) The FFI documentation says nothing about a load-time-value, and ffi::foreign-library is not mentioned either. Strange! My best guess is that CFFI is doing something strange with CLisp's FFI that has a better alternative. This feature of FFI that the CFFI developers chose may be broken on Windows 98. For a comparison, here is my SDL header code, which does work on Windows 98: (ffi:def-call-out SDL_Init (:name "SDL_Init") (:library "sdl.dll") (:return-type ffi:int) (:arguments (flags Uint32))) Okay, I could say "it works this way, but CFFI does it another way that is broken", but I don't know the ins and outs of CFFI, and why the developers chose to use the load-time-vaue macro (or whatever it is), so I won't comment on a better way to do it. But maybe CFFI's CLisp module could use a different feature of FFI to do its run-time DLL calls. Anyway, CFFI is a great project, and I had no headaches setting it up, so I'm very pleased with it. I don't even use Windows 98 (I'm on Windows XP), but it seems best to fix things so that my application and others will run on that platform, without people cursing Lisp. Cheers, Jeremy. -- | Jeremy Smith BSc (Hons) | Chief Scientist, Decompiler Technologies | Member, British Computer Society | England

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[cffi-devel] darcs patch: Add check for FreeBSD and remove some redundant assign...
by keriax＠gmail.com 01 Feb '06

01 Feb '06

Wed Feb 1 22:40:58 VLAT 2006 keriax(a)gmail.com * Add check for FreeBSD and remove some redundant assignments.

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[cffi-devel] darcs patch: Add check for FreeBSD and remove some redundant assign...
by keriax＠gmail.com 01 Feb '06

01 Feb '06

Wed Feb 1 22:40:58 VLAT 2006 keriax(a)gmail.com * Add check for FreeBSD and remove some redundant assignments.

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[cffi-devel] darcs patch: Added check for FreeBSD and removed some redundant code.
by keriax＠gmail.com 01 Feb '06

01 Feb '06

Wed Feb 1 21:50:45 VLAT 2006 keriax(a)gmail.com * Added check for FreeBSD and removed some redundant code.

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[cffi-devel] Bitfields and defcenum
by Luís Oliveira 01 Feb '06

01 Feb '06

Hello, While building CFFI bindings for GLUT and using enums for defining bitfield masks, I came across this example: (defcenum display-mode (:rgb 0) (:rgba 0) (:index 1) (:single 0) (:double 2) (:accum 4) (:alpha 8) (:depth 16) (:stencil 32) (:multisample 128) (:stereo 256) (:luminance 512)) defcenum won't accept this because it contains duplicate values. This a misfeature introduced by myself that I forgot to fix and people have complained[1] about this before. Unless someone has any objections, I'll implement something like what CLISP has. But this makes me wonder if another abstraction, say DEFBITFIELD would be useful. Something like: (defbitfield name (0 sym1 sym2 ...) (1 sym3) (2 sym4) ...) Along with type translator on these types that would construct an integer from a list of these symbols and vice-versa. Any other suggestions before I push a patch with something like this? BTW, I silently pushed a patch that adds a new option to defcenum by allowing a base-type (when the default, :int, is not appropriate). [1] http://article.gmane.org/gmane.lisp.cffi.devel/26 -- Luís Oliveira http://student.dei.uc.pt/~lmoliv/ Equipa Portuguesa do Translation Project http://www.iro.umontreal.ca/translation/registry.cgi?team=pt

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