My OpenAL code also uses stuff from alc.h, so I modified my binding def: (defbinding "openal-library" (nicknames "al") (flags "") (include "AL/al.h" "AL/alc.h" "AL/alut.h") (export "alenable" "aldisable") (override "")) This yielded amongst other good stuff: (cffi:defcstruct alcdevice-struct) ...on which we get divide-by-zero in CFFI because notice-foreign-struct-definition initializes max-align to zero and that never gets bumped up (because there are no slots and that is when it gets adjusted) and then gets used in a rem to determine padding. Checking alc.h and the rest of the al includes, I do not see any actual definition for alcdevice-struct. I guess the type is needed to define the functions which get passed a pointer to a device struct, but the actual make-up of the struct is pure internal. I will let you all fight it out, but it looks as if CFFI needs to be more tolerant? I will try initializing the max-align to 2 and see how much further I get. -- Kenny Why Lisp? http://lisp.tech.coop/RtL%20Highlight%20Film "I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it." Elwood P. Dowd, "Harvey", 1950
On 7/set/2005, at 04:49, Kenny Tilton wrote:
(cffi:defcstruct alcdevice-struct) [...] I will let you all fight it out, but it looks as if CFFI needs to be more tolerant? I will try initializing the max-align to 2 and see how much further I get.
CFFI needs bug fixing that's what it is. :-) Well, I can't find anything specific about empty structures in the ABI docs so I'm going to assume an empty struct indeed has size 0 and alignment 1 (or 0, whatever). I'll add a test for this too. -- Luís Oliveira http://student.dei.uc.pt/~lmoliv/ Equipa Portuguesa do Translation Project http://www2.iro.umontreal.ca/~pinard/po/registry.cgi?team=pt
Entertainingly enough, the C and C++ ABIs differ in this regard. C (even C99) says that sizeof(empty-struct) = 0, alignof(empty-struct) = 1 C++ says that sizeof(empty-struct) = 1, alignof(empty-struct) = 1 I say use the C layout, since Verrazano does its own layout for C++ that doesn't depend on what CFFI thinks the sizeof a type is. Sincerely, Rayiner hashem On 9/7/05, Luis Oliveira <luismbo@gmail.com> wrote:
On 7/set/2005, at 04:49, Kenny Tilton wrote:
(cffi:defcstruct alcdevice-struct) [...] I will let you all fight it out, but it looks as if CFFI needs to be more tolerant? I will try initializing the max-align to 2 and see how much further I get.
CFFI needs bug fixing that's what it is. :-)
Well, I can't find anything specific about empty structures in the ABI docs so I'm going to assume an empty struct indeed has size 0 and alignment 1 (or 0, whatever).
I'll add a test for this too.
-- Luís Oliveira http://student.dei.uc.pt/~lmoliv/ Equipa Portuguesa do Translation Project http://www2.iro.umontreal.ca/~pinard/po/registry.cgi?team=pt
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Luis Oliveira <luismbo@gmail.com> writes:
CFFI needs bug fixing that's what it is. :-)
Ah, right. Just above notice-foreign-struct-definition there was this comment of mine: ;;; TODO: figure out what to do with empty structures. Well, max-align should have been 1. Kenny, setting max-align to 2 is a bad idea. It'll break structs that have only chars. So, I've pushed a patch that fixes this and the respective regression test. -- Luis Oliveira luismbo (@) gmail (.) com Equipa Portuguesa do Translation Project http://www2.iro.umontreal.ca/~pinard/po/registry.cgi?team=pt
participants (3)
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Kenny Tilton -
Luis Oliveira -
Rayiner Hashem