external/cffi.darcs/tests/union.lisp

   1 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*-
   2 ;;;
   3 ;;; union.lisp --- Tests on C unions.
   4 ;;;
   5 ;;; Copyright (C) 2005-2006, James Bielman  <jamesjb@jamesjb.com>
   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-tests)
  29
  30 (defcunion uint32-bytes
  31   (int-value :unsigned-int)
  32   (bytes :unsigned-char :count 4))
  33
  34 (defun int-to-bytes (n)
  35   "Convert N to a list of bytes using a union."
  36   (with-foreign-object (obj 'uint32-bytes)
  37     (setf (foreign-slot-value obj 'uint32-bytes 'int-value) n)
  38     (loop for i from 0 below 4
  39           collect (mem-aref
  40                    (foreign-slot-value obj 'uint32-bytes 'bytes)
  41                    :unsigned-char i))))
  42
  43 (deftest union.1
  44     (let ((bytes (int-to-bytes #x12345678)))
  45       (cond ((equal bytes '(#x12 #x34 #x56 #x78))
  46              t)
  47             ((equal bytes '(#x78 #x56 #x34 #x12))
  48              t)
  49             (t bytes)))
  50   t)