3rdparties/software/cffi_0.21.0/src/foreign-vars.lisp (4066 bytes)
1 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*- 2 ;;; 3 ;;; foreign-vars.lisp --- High-level interface to foreign globals. 4 ;;; 5 ;;; Copyright (C) 2005-2008, Luis Oliveira <loliveira(@)common-lisp.net> 6 ;;; 7 ;;; Permission is hereby granted, free of charge, to any person 8 ;;; obtaining a copy of this software and associated documentation 9 ;;; files (the "Software"), to deal in the Software without 10 ;;; restriction, including without limitation the rights to use, copy, 11 ;;; modify, merge, publish, distribute, sublicense, and/or sell copies 12 ;;; of the Software, and to permit persons to whom the Software is 13 ;;; furnished to do so, subject to the following conditions: 14 ;;; 15 ;;; The above copyright notice and this permission notice shall be 16 ;;; included in all copies or substantial portions of the Software. 17 ;;; 18 ;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19 ;;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 ;;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 21 ;;; NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 22 ;;; HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 23 ;;; WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 24 ;;; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 25 ;;; DEALINGS IN THE SOFTWARE. 26 ;;; 27 28 (in-package #:cffi) 29 30 ;;;# Accessing Foreign Globals 31 32 ;;; Called by FOREIGN-OPTIONS in functions.lisp. 33 (defun parse-defcvar-options (options) 34 (destructuring-bind (&key (library :default) read-only) options 35 (list :library library :read-only read-only))) 36 37 (defun get-var-pointer (symbol) 38 "Return a pointer to the foreign global variable relative to SYMBOL." 39 (foreign-symbol-pointer (get symbol 'foreign-var-name) 40 :library (get symbol 'foreign-var-library))) 41 42 ;;; Note: this will lookup not only variables but also functions. 43 (defun foreign-symbol-pointer (name &key (library :default)) 44 (check-type name string) 45 (%foreign-symbol-pointer 46 name (if (eq library :default) 47 :default 48 (foreign-library-handle 49 (get-foreign-library library))))) 50 51 (defun fs-pointer-or-lose (foreign-name library) 52 "Like foreign-symbol-ptr but throws an error instead of 53 returning nil when foreign-name is not found." 54 (or (foreign-symbol-pointer foreign-name :library library) 55 (error "Trying to access undefined foreign variable ~S." foreign-name))) 56 57 (defmacro defcvar (name-and-options type &optional documentation) 58 "Define a foreign global variable." 59 (multiple-value-bind (lisp-name foreign-name options) 60 (parse-name-and-options name-and-options t) 61 (let ((fn (symbolicate '#:%var-accessor- lisp-name)) 62 (read-only (getf options :read-only)) 63 (library (getf options :library))) 64 ;; We can't really setf an aggregate type. 65 (when (aggregatep (parse-type type)) 66 (setq read-only t)) 67 `(progn 68 (setf (documentation ',lisp-name 'variable) ,documentation) 69 ;; Save foreign-name and library for posterior access by 70 ;; GET-VAR-POINTER. 71 (setf (get ',lisp-name 'foreign-var-name) ,foreign-name) 72 (setf (get ',lisp-name 'foreign-var-library) ',library) 73 ;; Getter 74 (defun ,fn () 75 (mem-ref (fs-pointer-or-lose ,foreign-name ',library) ',type)) 76 ;; Setter 77 (defun (setf ,fn) (value) 78 ,(if read-only '(declare (ignore value)) (values)) 79 ,(if read-only 80 `(error ,(format nil 81 "Trying to modify read-only foreign var: ~A." 82 lisp-name)) 83 `(setf (mem-ref (fs-pointer-or-lose ,foreign-name ',library) 84 ',type) 85 value))) 86 ;; While most Lisps already expand DEFINE-SYMBOL-MACRO to an 87 ;; EVAL-WHEN form like this, that is not required by the 88 ;; standard so we do it ourselves. 89 (eval-when (:compile-toplevel :load-toplevel :execute) 90 (define-symbol-macro ,lisp-name (,fn)))))))