src/compiler/compiler-deftype.lisp

   1 ;;;; that part of DEFTYPE which runs within the compiler itself
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!IMPL")
  13
  14 (/show0 "compiler-deftype.lisp 14")
  15
  16 (defun %compiler-deftype (name lambda-list expander doc source-location)
  17   (with-single-package-locked-error
  18       (:symbol name "defining ~A as a type specifier"))
  19   (ecase (info :type :kind name)
  20     (:primitive
  21      (when *type-system-initialized*
  22        (error "illegal to redefine standard type: ~S" name)))
  23     (:instance
  24      (warn "The class ~S is being redefined to be a DEFTYPE." name)
  25      (undeclare-structure (find-classoid name) t)
  26      ;; FIXME: shouldn't this happen only at eval-time?
  27      (setf (classoid-cell-classoid (find-classoid-cell name :create t)) nil)
  28      (setf (info :type :compiler-layout name) nil)
  29      (setf (info :type :kind name) :defined))
  30     (:defined
  31      ;; Note: It would be nice to warn here when a type is being
  32      ;; incompatibly redefined, but it's hard to tell, since type
  33      ;; expanders are often function objects which can't easily be
  34      ;; compared for equivalence. And just warning on redefinition
  35      ;; isn't good, since DEFTYPE necessarily does its thing once at
  36      ;; compile time and again at load time, so that it's very common
  37      ;; and normal for types to be defined twice. So since there
  38      ;; doesn't seem to be anything simple and obvious to do, and
  39      ;; since mistakenly redefining a type isn't a common error
  40      ;; anyway, we just don't worry about trying to warn about it.
  41      )
  42     ((nil :forthcoming-defclass-type)
  43      (setf (info :type :kind name) :defined)))
  44   (setf (info :type :expander name) expander
  45         (info :type :lambda-list name) lambda-list)
  46   (sb!c:with-source-location (source-location)
  47     (setf (info :type :source-location name) source-location))
  48   (when doc
  49     (setf (fdocumentation name 'type) doc))
  50   ;; ### Bootstrap hack -- we need to define types before %NOTE-TYPE-DEFINED
  51   ;; is defined. (FIXME: Do we still need to do this? -- WHN 19990310)
  52   (if (fboundp 'sb!c::%note-type-defined)
  53     (sb!c::%note-type-defined name)
  54     (warn "defining type before %NOTE-TYPE-DEFINED is defined"))
  55   name)
  56
  57 (/show0 "compiler-deftype.lisp end of file")