stk/Lib/ffi.stk

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1998-04-10 06:59:06 -04:00
;;;;
;;;; f f i . s t k -- Foreign Function Interface for STk
;;;;
;;;; Copyright <20> 1997-1998 Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr>
;;;;
;;;; Permission to use, copy, and/or distribute this software and its
;;;; documentation for any purpose and without fee is hereby granted, provided
;;;; that both the above copyright notice and this permission notice appear in
;;;; all copies and derived works. Fees for distribution or use of this
;;;; software or derived works may only be charged with express written
;;;; permission of the copyright holder.
;;;; This software is provided ``as is'' without express or implied warranty.
;;;;
;;;; Author: Erick Gallesio [eg@unice.fr]
;;;; Creation date: 17-Sep-1997 12:35
;;;; Last file update: 8-Apr-1998 10:18
(select-module STk)
(define (ffi:arg-type type return?)
(let ((type (if (and (pair? type) (eq? '* (cadr type)))
;; We have (:xxx *). If xxx=char return :string,
;; :dynamic-ptr otherwise
(if (eq? :char (car type)) :string :dynamic-ptr)
type)))
;; DO NOT CHANGE the following values without changing the correponding
;; constants in the file dynload.c!!!!
(case type
((:void) (if return?
0
(error "define-external: void argument forbidden")))
((:char) 1)
((:short) 2)
((:ushort) 3)
((:int) 4)
((:uint) 5)
((:long) 6)
((:ulong) 7)
((:float) 8)
((:double) 9)
((:static-ptr) 10)
((:dynamic-ptr) 11)
((:string) 12)
((:boolean) 13)
(else (error "define-external: bad type: ~S" type)))))
(define (ffi:interface-type type) ;available calling conventions
(case type
((:c) 0) ;args pushed right-to-left, caller pops
((:argc/argv) 1) ;argv pushed, then argc, caller pops
((:winapi) 2))) ;args pushed left-to-right, callee pops
(define (ffi:parse-arglist l)
(letrec ((aux (lambda (l names types)
(cond
((null? l) (list names types names))
((pair? l) (aux (cdr l)
(append names (list (caar l)))
(append types
(list (ffi:arg-type (cadar l) #f)))))
(else (list (append names l)
(append types (ffi:arg-type :void #t))
(append names (list l))))))))
(aux l '() '())))
(define-macro (define-external name args . l)
(let* ((args (ffi:parse-arglist args))
(lib-name (get-keyword :library-name l ""))
(entry-name (get-keyword :entry-name l (symbol->string name)))
(return-type (ffi:arg-type (get-keyword :return-type l :void) #t))
(interface (ffi:interface-type (get-keyword :interface l :C)))
(names (car args))
(types (cadr args))
(actuals (caddr args))
(prologue `(,(if (string=? lib-name "")
""
(string-append lib-name "." *shared-suffix*))
,entry-name
,return-type
',names
',types)))
`(define ,name (lambda ,names
,(if (list? names)
`(%call-external ,@prologue ,@(copy-tree actuals))
`(apply %call-external ,@prologue
,@(copy-tree actuals)))))))
(define (external-exists? entry . lib)
(apply %external-exists?
entry
(list (if (null? lib)
""
(string-append (car lib) "." *shared-suffix*)))))
(provide "ffi")