;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10; Package: UFFI -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:          libraries.lisp
;;;; Purpose:       UFFI source to load foreign libraries
;;;; Programmer:    Kevin M. Rosenberg
;;;; Date Started:  Feb 2002
;;;;
;;;; $Id: libraries.lisp,v 1.8 2003/06/26 18:02:08 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.
;;;; *************************************************************************

(in-package #:uffi)

(defvar *loaded-libraries* nil
  "List of foreign libraries loaded. Used to prevent reloading a library")

(defun default-foreign-library-type ()
  "Returns string naming default library type for platform"
  #+(or win32 mswindows) "dll"
  #+(or macosx darwin ccl-5.0) "dylib"
  #-(or win32 mswindows macosx darwin ccl-5.0) "so"
)

(defun find-foreign-library (names directories &key types drive-letters)  
  "Looks for a foreign library. directories can be a single
string or a list of strings of candidate directories. Use default
library type if type is not specified."
  (unless types
    (setq types (default-foreign-library-type)))
  (unless (listp types)
    (setq types (list types)))
  (unless (listp names)
    (setq names (list names)))
  (unless (listp directories)
    (setq directories (list directories)))
  #+(or win32 mswindows)
  (unless (listp drive-letters)
    (setq drive-letters (list drive-letters)))
  #-(or win32 mswindows)
  (setq drive-letters '(nil))
  (dolist (drive-letter drive-letters)
    (dolist (name names)
      (dolist (dir directories)
	(dolist (type types)
	  (let ((path (make-pathname 
		       #+lispworks :host
		       #+lispworks (when drive-letter drive-letter)
		       #-lispworks :device
		       #-lispworks (when drive-letter drive-letter)
		       :name name 
		       :type type
		       :directory 
		       (etypecase dir
			 (pathname
			  (pathname-directory dir))
			 (list
			  dir)
			 (string
			  (pathname-directory 
			   (parse-namestring dir)))))))
	    (when (probe-file path)
	      (return-from find-foreign-library path)))))))
   nil)


(defun load-foreign-library (filename &key module supporting-libraries
					   force-load)
  #+(or allegro lispworks mcl) (declare (ignore module supporting-libraries))
  #+(or cmu scl sbcl) (declare (ignore module))
  
  (when (and filename (probe-file filename))
    (if (pathnamep filename)    ;; ensure filename is a string to check if
	(setq filename (namestring filename)))  ; already loaded

    (if (and (not force-load)
	     (find filename *loaded-libraries* :test #'string-equal))
	t ;; return T, but don't reload library
      (progn
	#+cmu
	(let ((type (pathname-type (parse-namestring filename))))
	  (if (string-equal type "so")
	      (sys::load-object-file filename)
	      (alien:load-foreign filename 
				  :libraries
				  (convert-supporting-libraries-to-string
				   supporting-libraries))))
	#+scl
	(let ((type (pathname-type (parse-namestring filename))))
	  (alien:load-foreign filename 
			      :libraries
			      (convert-supporting-libraries-to-string
			       supporting-libraries)))
	#+sbcl
	(if (string-equal type "so")
	    (sb-alien::load-1-foreign filename)
	    (sb-alien:load-foreign filename 
				   :libraries
				   (convert-supporting-libraries-to-string
				    supporting-libraries)))
	#+lispworks (fli:register-module module :real-name filename)
	#+allegro (load filename)
	#+openmcl (ccl:open-shared-library filename)
	#+(and mcl (not openmcl)) (ccl:add-to-shared-library-search-path filename t)
	
	(push filename *loaded-libraries*)
	t))))

(defun convert-supporting-libraries-to-string (libs)
  (let (lib-load-list)
    (dolist (lib libs)
      (push (format nil "-l~A" lib) lib-load-list))
    (nreverse lib-load-list)))