March 2007 - cffi-devel - mailman3.common-lisp.net

[cffi-devel] cffi-sys::default-encoding returns nil on clisp/mingw
by Jack Unrue 01 May '07

01 May '07

Running CLISP on my system with the newtypes branch, I find that the CFFI-SYS::DEFAULT-ENCODING function is returning NIL. Some poking around reveals that CUSTOM:*FOREIGN-ENCODING* is set to #<ENCODING CHARSET:CP1252 :DOS> I looked at the symbol values for everything in the :charset package, and they all specify :UNIX instead of :DOS and so that's what CFFI-SYS::*ENCODINGS* and CFFI-SYS::*CLISP-ENCODINGS* get populated with. So I can see why DEFAULT-ENCODING is returning NIL. Before I head over to clisp-devel and ask about this, I just wanted to see whether this situation surprises anyone here, or if you think it might be a CLISP build configuration issue (which would be funny because I'm one of the MingW package maintainers), or ??? For instance, can anyone point me at a spot in the CLISP manual that states that *FOREIGN-ENCODING* will always correspond to the value of one of the symbols in the :charset package? This is on WinXP SP2, CLISP 2.41 (mingw special) with nothing related to encoding for command-line arguments. -- Jack Unrue

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[cffi-devel] Patch that adds an example of arrays to the documentation of defcstruct
by Ignas Mikalajunas 17 Apr '07

17 Apr '07

Hi, some users are not very attentive when reading documentation and rely on examples so i just though that it would be useful to have an example of an array defined as a member of a c struct in the manual. Ignas

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[cffi-devel] load-foreign-library on LispWorks 5.0.1
by Jack Unrue 29 Mar '07

29 Mar '07

I believe there is a problem with how fli:register-module is called (this is on LispWorks 5.0.1) when the application uses load-foreign-library. The short story is that this is causing load-foreign-library to throw an error on LispWorks. Long story...assume that I haven't added anything to *foreign-library-directories* and consider the following (cffi:load-foreign-library "user32.dll") This causes cffi::load-foreign-library-helper to be called because I'm passing a string rather than a symbol. Thus we call cffi:load-foreign-library-path, passing nil for the library parameter, which calls the LW-specific %load-foreign-library function. That ends up calling fli:register-module which apparently wants a non-nil value for its first argument. Like so: CL-USER 5 > (fli:register-module nil :connection-style :immediate :real-name "user32.dll") NIL CL-USER 6 > (fli:register-module 'mylib :connection-style :immediate :real-name "user32.dll") MYLIB The latter is effectively what happens when the application uses define-foreign-library and then use-foreign-library, and I confirmed that this latter approach works where load-foreign-library doesn't. I'm not sure what the proper fix is (i.e., creating a symbol out of the path string might not be such a hot idea), otherwise I'd offer a patch. BTW, I think this may be a behavioral change going from LW 5.0 to 5.0.1, because I don't remember having this problem on 5.0. -- Jack Unrue

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[cffi-devel] newtypes compile error with LispWorks 5.0.1
by Jack Unrue 28 Mar '07

28 Mar '07

Hello. I'm getting the following compile errors in cffi-lispworks.lisp from the newtypes branch under LW 5.0.1 (WinXP): **++++ Error in CFFI-SYS:%FOREIGN-STRING-LENGTH: Undefined operator CONVERT-FOREIGN-TYPED-AREF-TYPE in form (CONVERT-FOREIGN-TYPED-AREF-TYPE TYPE). **++++ Error in CFFI-SYS:%LISP-STRING-INTO-FOREIGN: Undefined operator CONVERT-FOREIGN-TYPED-AREF-TYPE in form (CONVERT-FOREIGN-TYPED-AREF-TYPE TYPE). I see that there are compiler macros defined for %MEM-REF and %MEM-SET which call CONVERT-FOREIGN-TYPED-AREF-TYPE. With a copy&paste into the REPL, I'm able to define that function manually. Also (cl:find-symbol "FOREIGN-TYPED-AREF" "FLI") returns T on my machine. And that's about where my expertise with compiler macros drops off into the abyss. Any idea what's going wrong? Thanks. -- Jack Unrue

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[cffi-devel] cffi-tests coverage report
by Luis Oliveira 20 Mar '07

20 Mar '07

Hello, Juho Snellman recently[1] posted a very useful SBCL-specific coverage tool. I did this for CFFI to test the coverage of cffi-tests. The report can be found here: <http://common-lisp.net/~loliveira/tmp/cffi-tests-coverage/> The results seem pretty good to me: 80.5% code coverage. It does reveal some missed spots so if someone feels like writing some tests, look at this report for picking where to start. :-) A significant percentage of these missed spots are a result of compiler macros (or type expansions) kicking in or error branches not being exercised. [1] http://thread.gmane.org/gmane.lisp.steel-bank.devel/8721 -- Luís Oliveira http://student.dei.uc.pt/~lmoliv/

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[cffi-devel] Mac OS X / intel support
by Carlos Lenz 19 Mar '07

19 Mar '07

Hi The "implementation support" section of the CFFI manual lists darwin/ppc as being supported for several lisps, but says nothing about darwin/intel. Nevertheless I have tried to install it in CLISP - Mac OS X and got several errors. Is it supported? Do you want to see the errors? Regards Carlos

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[cffi-devel] how to revise foreign type translators to work with cffi-newtypes
by Jack Unrue 15 Mar '07

15 Mar '07

Hi there. I'm looking into some compile errors that are reported by SBCL when compiling Graphic-Forms using the cffi-newtypes branch. I have a number of foreign types defined, and for a couple of these, I also declare aliases for :pointer such that I am then able to implement type translators. Here's an example (assume there are existing CL structures called RECTANGLE, SIZE, and POINT, and it is instances of RECTANGLE which are to be translated into and out of the foreign struct RECT that I'm defining below): (cffi:defctype rect-pointer :pointer) (cffi:defcstruct rect (left :long) (top :long) (right :long) (bottom :long)) (defmethod cffi:free-translated-object (ptr (name (eql 'rect-pointer)) param) (declare (ignore param)) (cffi:foreign-free ptr)) (defmethod cffi:translate-from-foreign (ptr (name (eql 'rect-pointer))) (if (cffi:null-pointer-p ptr) (make-rectangle) (cffi:with-foreign-slots ((left top right bottom) ptr rect) (let ((pnt (make-point :x left :y top)) (size (make-size :width (- right left) :height (- bottom top)))) (make-rectangle :location pnt :size size))))) (defmethod cffi:translate-to-foreign ((lisp-rect rectangle) (name (eql 'rect-pointer))) (let ((ptr (cffi:foreign-alloc 'rect)) (pnt (location lisp-rect)) (size (size lisp-rect))) (cffi:with-foreign-slots ((left top right bottom) ptr rect) (setf left (gfs:point-x pnt) top (gfs:point-y pnt) right (+ (gfs:point-x pnt) (gfs:size-width size)) bottom (+ (gfs:point-y pnt) (gfs:size-height size)))) ptr)) Can anyone make suggestions as to what I should change to be compatible with the cffi-newtypes branch? Second question -- do the WITH-FOREIGN-SLOTS and WITH-FOREIGN-OBJECT macros work the same way on cffi-newtypes as they did before? I imagine so, but it's worth asking just to be sure. Thanks in advance. -- Jack Unrue

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Re: [cffi-devel] Re: Passing Lisp values into and back out of C?
by Luís Oliveira 14 Mar '07

14 Mar '07

On 14/03/07, Robert Goldman <rpgoldman(a)real-time.com> wrote: > IIUC, this is pretty similar to what Allegro does with its memref trick. > So you might want a big #-allegro around this if you were going to do it! Hmm, I don't think so. SYS:MEMREF seems pretty low-level to me: <http://www.franz.com/support/documentation/8.0/doc/operators/system/memref.…> -- Luís Oliveira http://student.dei.uc.pt/~lmoliv/

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[cffi-devel] Passing Lisp values into and back out of C?
by Peter Seibel 14 Mar '07

14 Mar '07

This must either be really trivial or completely impossible: suppose I need to create an instance of a C structure that has a void* slot. I want to fill that slot with (some representation of) an arbitrary Lisp value so that when that structure is handed back to my Lisp code I can get back to the Lisp object. Other than keeping my own integer->object mapping and passing the integer to C and translating it back to the object when I get it back, is there some easier way to do this in CFFI? -Peter -- Peter Seibel : peter(a)gigamonkeys.com Gigamonkeys Consulting : http://www.gigamonkeys.com/

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[cffi-devel] How would you like an extra $500 - $1000 a week with 15 minutes of your time ?
by Work＠common-lisp.net 08 Mar '07

08 Mar '07

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