;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10; Package: UFFI -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:          objects.cl
;;;; Purpose:       UFFI source to handle objects and pointers
;;;; Programmer:    Kevin M. Rosenberg
;;;; Date Started:  Feb 2002
;;;;
;;;; $Id: objects.lisp,v 1.4 2002/10/16 11:56:43 kevin Exp $
;;;;
;;;; This file, part of UFFI, is Copyright (c) 2002 by Kevin M. Rosenberg
;;;;
;;;; UFFI users are granted the rights to distribute and use this software
;;;; as governed by the terms of the Lisp Lesser GNU Public License
;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
;;;; *************************************************************************

(declaim (optimize (debug 3) (speed 3) (safety 1) (compilation-speed 0)))
(in-package :uffi)

(defun size-of-foreign-type (type)
  #+lispworks (fli:size-of type)
  #+allegro (ff:sizeof-fobject type)
  #+(or cmu scl)  (ash (eval `(alien:alien-size ,type)) -3) ;; convert from bits to bytes
  #+sbcl  (ash (eval `(sb-alien:alien-size ,type)) -3) ;; convert from bits to bytes
  #+clisp (values (ffi:size-of type))
  #+(and mcl (not openmcl))
  (let ((mcl-type (ccl:find-mactype type nil t)))
    (if mcl-type 
	(ccl::mactype-record-size mcl-type)
      (ccl::record-descriptor-length (ccl:find-record-descriptor type t t)))) ;error if not a record
  #+openmcl (ccl::%foreign-type-or-record-size type :bytes)
  )


(defmacro allocate-foreign-object (type &optional (size :unspecified))
  "Allocates an instance of TYPE. If size is specified, then allocate
an array of TYPE with size SIZE. The TYPE parameter is evaluated."
  (if (eq size :unspecified)
      (progn
	#+(or cmu scl)
	`(alien:make-alien ,(convert-from-uffi-type (eval type) :allocation))
	#+sbcl
	`(sb-alien:make-alien ,(convert-from-uffi-type (eval type) :allocation))
	#+lispworks
	`(fli:allocate-foreign-object :type ',(convert-from-uffi-type type :allocate))
	#+allegro
	`(ff:allocate-fobject ,(convert-from-uffi-type type :allocate) :c)
	#+mcl
	`(new-ptr ,(size-of-foreign-type (convert-from-uffi-type type :allocation)))
	)
      (progn
	#+(or cmu scl)
	`(alien:make-alien ,(convert-from-uffi-type (eval type) :allocation) ,size)
	#+sbcl
	`(sb-alien:make-alien ,(convert-from-uffi-type (eval type) :allocation) ,size)
	#+lispworks
	`(fli:allocate-foreign-object :type ',(convert-from-uffi-type type :allocate) :nelems ,size)
	#+allegro
	`(ff:allocate-fobject '(:array ,(convert-from-uffi-type (eval type) :allocate) ,(eval size)) :c)
	#+mcl
	`(new-ptr (* ,size ,(size-of-foreign-type (convert-from-uffi-type type :allocation))))
	)))

(defmacro free-foreign-object (obj)
  #+(or cmu scl)
  `(alien:free-alien ,obj)
  #+sbcl
  `(sb-alien:free-alien ,obj)
  #+lispworks
  `(fli:free-foreign-object ,obj)
  #+allegro
  `(ff:free-fobject ,obj)
  #+mcl
  `(dispose-ptr ,obj)
  )

(defmacro null-pointer-p (obj)
  #+lispworks `(fli:null-pointer-p ,obj)
  #+allegro `(zerop ,obj)
  #+(or cmu scl)   `(alien:null-alien ,obj)
  #+sbcl   `(sb-alien:null-alien ,obj)
  #+mcl   `(ccl:%null-ptr-p ,obj)
  )

(defmacro make-null-pointer (type)
  #+(or allegro mcl) (declare (ignore type))
  #+(or cmu scl) `(alien:sap-alien (system:int-sap 0) (* ,(convert-from-uffi-type (eval type) :type)))
  #+sbcl `(sb-alien:sap-alien (sb-sys:int-sap 0) (* ,(convert-from-uffi-type (eval type) :type)))
  #+lispworks `(fli:make-pointer :address 0 :type (quote ,(convert-from-uffi-type (eval type) :type)))
  #+allegro 0
  #+mcl `(ccl:%null-ptr)
  )

(defmacro char-array-to-pointer (obj)
  #+(or cmu scl) `(alien:cast ,obj (* (alien:unsigned 8)))
  #+sbcl `(sb-alien:cast ,obj (* (sb-alien:unsigned 8)))
  #+lispworks `(fli:make-pointer :type '(:unsigned :char)
				:address (fli:pointer-address ,obj))
  #+allegro obj
  #+mcl obj
  )

(defmacro deref-pointer (ptr type)
  "Returns a object pointed"
  #+(or cmu sbcl lispworks scl) (declare (ignore type))
  #+(or cmu scl)  `(alien:deref ,ptr)
  #+sbcl  `(sb-alien:deref ,ptr)
  #+lispworks `(fli:dereference ,ptr)
  #+allegro `(ff:fslot-value-typed ,(convert-from-uffi-type type :deref) :c ,ptr)
  #+mcl `(ccl:pref ,ptr ,(convert-from-uffi-type type :deref))
  )

#+mcl
(defmacro deref-pointer-set (ptr type value)
  `(setf (ccl:pref ,ptr ,(convert-from-uffi-type type :deref)) ,value))

#+mcl
(defsetf deref-pointer deref-pointer-set)

#+(or lispworks (and mcl (not openmcl))) ;; with LW, deref is a character
(defmacro ensure-char-character (obj)
  obj)

#+(or allegro cmu sbcl scl openmcl)
(defmacro ensure-char-character (obj)
  `(code-char ,obj))
  
#+(or lispworks (and mcl (not openmcl)))
(defmacro ensure-char-integer (obj)
 `(char-code ,obj))

#+(or allegro cmu sbcl scl openmcl)
(defmacro ensure-char-integer (obj)
  obj)

(defmacro pointer-address (obj)
  #+(or cmu scl)
  `(system:sap-int (alien:alien-sap ,obj))
  #+sbcl
  `(sb-sys:sap-int (sb-alien:alien-sap ,obj))
  #+lispworks
  `(fli:pointer-address ,obj)
  #+allegro
  obj
  #+mcl
  `(ccl:%ptr-to-int ,obj)  
  )

;; TYPE is evaluated.
#-mcl
(defmacro with-foreign-object ((var type) &rest body)
  #-(or cmu sbcl lispworks scl) ; default version
  `(let ((,var (allocate-foreign-object ,type)))
    (unwind-protect
	 (progn ,@body)
      (free-foreign-object ,var)))
  #+(or cmu scl)
  (let ((obj (gensym)))
    `(alien:with-alien ((,obj ,(convert-from-uffi-type (eval type) :allocate)))
       (let ((,var (alien:addr ,obj)))
	 ,@body)))
  #+sbcl
  (let ((obj (gensym)))
    `(sb-alien:with-alien ((,obj ,(convert-from-uffi-type (eval type) :allocate)))
       (let ((,var (sb-alien:addr ,obj)))
	 ,@body)))
  #+lispworks
  `(fli:with-dynamic-foreign-objects ((,var ,(convert-from-uffi-type
					      (eval type) :allocate)))
    ,@body)
  )

#-mcl
(defmacro with-foreign-objects (bindings &rest body)
  (if bindings
      `(with-foreign-object ,(car bindings)
	(with-foreign-objects ,(cdr bindings)
	  ,@body))
      `(progn ,@body)))

#+mcl
(defmacro with-foreign-objects (bindings &rest body)
  (let ((params nil) type count)
    (dolist (spec (reverse bindings)) ;keep order - macroexpands to let*
      (setf type (convert-from-uffi-type (eval (nth 1 spec)) :allocate))
      (setf count 1)
      (when (and (listp type) (eq (first type) :array))
        (setf count (nth 2 type))
        (unless (integerp count) (error "Invalid size for array: ~a" type))
        (setf type (nth 1 type)))
      (push (list (first spec) (* count (size-of-foreign-type type))) params))
    `(ccl:%stack-block ,params ,@body)))
				 
#+mcl
(defmacro with-foreign-object ((var type) &rest body)
  `(with-foreign-objects ((,var ,type)) 
     ,@body))