[fetter-devel] various

[Kenny Tilton]

After a little wrestling with Verrazano I am now trying to port my 
existing OpenAL demo to use the CFFI bindings generated by VZN.

I got a couple of warnings from ACL:

Warning: :call-direct ignored; no argument types specified.
; While compiling (:TOP-LEVEL-FORM "openal-lib2.lisp" 10554) in 
C:\0dev\cl-openal\openal-lib2.lisp:

Why the Hell are they not reporting on which defun? I will go digging to 
see if I can find which, but it may not matter. Anyway, I took a look at 
the expansion of:

(cffi:defcfun ("alutUnloadWAV" alutunloadwav) alvoid
         (anonymous1 :int) (anonymous2 :pointer)
         (anonymous3 :unsigned-int) (anonymous4 :unsigned-int))

namely....

(PROGN (FF:DEF-FOREIGN-CALL (|%cffi-foreign-function/ALUTUNLOADWAV| 
"alutUnloadWAV")
                            ((#:G1004 :INT INTEGER) (#:G1005 (* :VOID) 
INTEGER)
                             (#:G1006 :UNSIGNED-INT INTEGER) (#:G1007 
:UNSIGNED-INT INTEGER))
                            :RETURNING (:VOID NULL) :CALL-DIRECT T 
:ARG-CHECKING NIL
                            :STRINGS-CONVERT NIL)
       (DEFUN ALUTUNLOADWAV (ANONYMOUS1 ANONYMOUS2 ANONYMOUS3 ANONYMOUS4)
         (CFFI::TRANSLATE-OBJECTS (#:G1000 #:G1001 #:G1002 #:G1003)
           (ANONYMOUS1 ANONYMOUS2 ANONYMOUS3 ANONYMOUS4)
           (:INT :POINTER :UNSIGNED-INT :UNSIGNED-INT) ALVOID
           (|%cffi-foreign-function/ALUTUNLOADWAV| #:G1000 #:G1001 
#:G1002 #:G1003))))

I think there is a problem here in that the raw entry 
|%cffi-foreign-function/ALUTUNLOADWAV| is not really an inviting way to 
code raw calls to the API. Maybe I am wrong on this--perhaps the idea is 
that one would relatively rarely want to convert values explicitly and 
then call the raw function, so it is OK to make users write something like:

(defun alutunloadwav-raw (a1 a2 a3 a4) 
(|%cffi-foreign-function/ALUTUNLOADWAV a1 a2 a3 a4)

But is that raw name reliable between CFFI releases?

What I did with my FFI utils was reserve the C name for raw functions 
and use the Lispified name for functions which autoconverted parameters 
and return values. I also allowed for pre- and post-processing.

-- 
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