src/code/alien-type.lisp

   1 ;;;; ALIEN-related type system stuff, done later
   2 ;;;; than other type system stuff because it depends on the definition
   3 ;;;; of the ALIEN-VALUE target structure type
   4
   5 ;;;; This software is part of the SBCL system. See the README file for
   6 ;;;; more information.
   7 ;;;;
   8 ;;;; This software is derived from the CMU CL system, which was
   9 ;;;; written at Carnegie Mellon University and released into the
  10 ;;;; public domain. The software is in the public domain and is
  11 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  12 ;;;; files for more information.
  13
  14 (in-package "SB!KERNEL")
  15
  16 (/show0 "code/alien-type.lisp 16")
  17
  18 (!begin-collecting-cold-init-forms)
  19
  20 (!define-type-class alien :enumerable nil :might-contain-other-types nil)
  21
  22 (!define-type-method (alien :negate) (type)
  23   (make-negation-type :type type))
  24
  25 (!define-type-method (alien :unparse) (type)
  26   `(alien ,(unparse-alien-type (alien-type-type-alien-type type))))
  27
  28 (!define-type-method (alien :simple-subtypep) (type1 type2)
  29   (values (alien-subtype-p (alien-type-type-alien-type type1)
  30                            (alien-type-type-alien-type type2))
  31           t))
  32
  33 ;;; KLUDGE: This !DEFINE-SUPERCLASSES gets executed much later than the
  34 ;;; others (toplevel form time instead of cold load init time) because
  35 ;;; ALIEN-VALUE itself is a structure which isn't defined until fairly
  36 ;;; late.
  37 (!define-superclasses alien ((alien-value)) progn)
  38
  39 (!define-type-method (alien :simple-=) (type1 type2)
  40   (let ((alien-type-1 (alien-type-type-alien-type type1))
  41         (alien-type-2 (alien-type-type-alien-type type2)))
  42     (values (or (eq alien-type-1 alien-type-2)
  43                 (alien-type-= alien-type-1 alien-type-2))
  44             t)))
  45
  46 (!def-type-translator alien (&optional (alien-type nil))
  47   (typecase alien-type
  48     (null
  49      (make-alien-type-type))
  50     (alien-type
  51      (make-alien-type-type alien-type))
  52     (t
  53      (make-alien-type-type (parse-alien-type alien-type (make-null-lexenv))))))
  54
  55 (defun make-alien-type-type (&optional alien-type)
  56   (if alien-type
  57       (let ((lisp-rep-type (compute-lisp-rep-type alien-type)))
  58         (if lisp-rep-type
  59             (single-value-specifier-type lisp-rep-type)
  60             (%make-alien-type-type alien-type)))
  61       *universal-type*))
  62
  63 (!defun-from-collected-cold-init-forms !alien-type-cold-init)
  64
  65 (/show0 "code/alien-type.lisp end of file")