src/syscalls/designators.lisp

   1 ;;;; -*- Mode: Lisp; indent-tabs-mode: nil -*-
   2 ;;;
   3 ;;; --- CFFI type designators.
   4 ;;;
   5
   6 (in-package :iolib.syscalls)
   7
   8 ;;;-------------------------------------------------------------------------
   9 ;;; CFFI Type Designators
  10 ;;;-------------------------------------------------------------------------
  11
  12 (defmacro define-designator (name cffi-type &body type-clauses)
  13   (let ((type `(quote (or ,@(mapcar #'car type-clauses))))
  14         (ctype (format-symbol t "~A-~A" (string name) (string '#:designator))))
  15     `(progn
  16        (deftype ,name () ,type)
  17        (defun ,name (,name)
  18          (etypecase ,name
  19            ,@type-clauses))
  20        (define-foreign-type ,ctype ()
  21          ()
  22          (:simple-parser ,ctype)
  23          (:actual-type ,cffi-type))
  24        (defmethod expand-to-foreign (value (type ,ctype))
  25          `(convert-to-foreign
  26            (let ((,',name ,value))
  27              (etypecase ,',name ,@',type-clauses))
  28            ,',cffi-type)))))
  29
  30 (define-designator pointer-or-nil :pointer
  31   (null (null-pointer))
  32   (foreign-pointer pointer-or-nil))
  33
  34 (define-designator bool :int
  35   (null 0)
  36   (t    1))
  37 \f
  38
  39 ;;;-------------------------------------------------------------------------
  40 ;;; Other Types
  41 ;;;-------------------------------------------------------------------------
  42
  43 ;;; FIXME: with fd namespaces on Linux, someday this might be no
  44 ;;; longer correct
  45 (deftype fd   () '(integer 0 65535))