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;;;; -*- Mode: Lisp; Syntax: Common-Lisp; Package: CLOS -*-
;;;;
;;;; Copyright (c) 1992, Giuseppe Attardi.
;;;; Copyright (c) 2010, Jean-Claude Beaudoin.
;;;;
;;;; This program is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
;;;; version 3 of the License, or (at your option) any later version.
;;;;
;;;; See file '../../Copyright' for full details.
(defpackage "CLOS"
(:use "CL")
(:import-from "SI"
"UNBOUND" "GET-SYSPROP" "PUT-SYSPROP" "REM-SYSPROP"
"SIMPLE-PROGRAM-ERROR"))
(in-package "CLOS")
(do-external-symbols (sym) (unexport sym)) ;; clear the package exports. JCB
;;; During bootstrap these need to be redefined at some point
;;; and thus cannot be load-time evaluated.
#+mkcl-bootstrap
(proclaim '(notinline clos::find-slot-definition
cl::ensure-generic-function
clos::method-p
cl::make-method
cl::add-method
cl::find-method
cl::remove-method
clos::register-method-as-spec-user
clos::compute-effective-method
clos::setf-find-class
cl::warn
si::universal-error-handler))
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;;;
;;;
(defvar *warn-on-redefinition* #|'(:class :generic-function :method :function)|# nil)
;;;
;;;
(defvar +inside-make-instance+ nil)
(defvar +metadata-lock+ (mt:make-lock :name '+metadata-lock+ :recursive t))
(defmacro with-metadata-lock (&body body)
`(mt:with-lock (+metadata-lock+) ,@body)
)
(defmacro without-metadata-lock (&body body)
`(mt:without-lock (+metadata-lock+) ,@body)
)
;;;----------------------------------------------------------------------
;;; BOOTSTRAP FUNCTIONS TO ACCESS SLOTS
;;;
;;; MKCL has some restictions regarding the basic classes CLASS,
;;; STANDARD-CLASS and STANDARD-GENERIC-FUNCTION. These are that, certain
;;; slots must have pre-defined positions which cannot change. That means
;;; that a user can extend these classes, but they must be the first ones
;;; in the class hierarchy, and the position of their slots must not change.
(eval-when (compile eval)
(defun create-accessors (slotds type)
(let ((i 0)
(output '())
name)
(dolist (s slotds `(progn ,@output))
(when (setf name (getf (cdr s) :accessor))
(remf (cdr s) :accessor)
(setf output
(append output
`((defun ,name (obj)
(si:instance-ref obj ,i))
(defsetf ,name (obj) (x)
`(si:instance-set ,obj ,,i ,x))
#+nil
(define-compiler-macro ,name (obj)
`(si:instance-ref ,obj ,,i))
))))
(incf i))))
)
;;; ----------------------------------------------------------------------
;;; Class CLASS
;; The position of the first 5 slots of this object is hardcoded in object.h
(eval-when (compile eval)
(defparameter +class-slots+
'((name :initarg :name :initform nil :accessor class-id)
(direct-superclasses :initarg :direct-superclasses :accessor class-direct-superclasses)
(direct-subclasses :initform nil :accessor class-direct-subclasses)
(slots :accessor class-slots)
(precedence-list :accessor class-precedence-list)
(direct-slots :initarg :direct-slots :accessor class-direct-slots)
(direct-default-initargs :initarg :direct-default-initargs
:initform nil :accessor class-direct-default-initargs)
(default-initargs :accessor class-default-initargs)
(finalized :initform nil :accessor class-finalized-p)
(documentation :initarg :documentation :initform nil :accessor class-documentation)
(size :accessor class-size)
(sealedp :initarg :sealedp :initform nil :accessor class-sealedp)
(cached-make-instance :initform nil :accessor class-cached-make-instance)
(prototype)
(version :initarg :version :initform 0 :accessor class-version)
(previous :initarg :previous :initform nil :accessor class-previous)
(source :initarg :source :initform nil :accessor class-source)
(spec-users :initarg :spec-users :initform nil :accessor class-spec-users)
)))
#.(create-accessors +class-slots+ 'class)
;;; ----------------------------------------------------------------------
;;; STANDARD-CLASS
(eval-when (compile eval)
(defparameter +standard-class-slots+
(append +class-slots+
'((slot-table :accessor slot-table) ;; Not MOP! JCB
(optimize-slot-access :accessor class-optimize-slot-access) ;; Not MOP either! JCB
))))
#.(create-accessors +standard-class-slots+ 'standard-class)
;;; ----------------------------------------------------------------------
;;; STANDARD-GENERIC-FUNCTION
;; The position of the first 3 slots of this object are hardcoded in gfun.d and internal.h
(eval-when (compile eval)
(defparameter +standard-generic-function-slots+
'((name :initarg :name :initform nil
:accessor generic-function-name)
(spec-list :initform nil :accessor generic-function-spec-list)
(method-combination
:initarg :method-combination :initform '(standard)
:accessor generic-function-method-combination)
(lambda-list :initarg :lambda-list
:accessor generic-function-lambda-list)
(argument-precedence-order
:initarg :argument-precedence-order
:initform nil
:accessor generic-function-argument-precedence-order)
(method-class
:initarg :method-class
:initform (find-class 'standard-method)
:accessor generic-function-method-class)
(documentation :initarg :documentation :initform nil :accessor generic-function-documentation)
(methods :initform nil :accessor generic-function-methods)
(a-p-o-function :initform nil :accessor generic-function-a-p-o-function)
(version :initarg :version :initform 0 :accessor generic-function-version)
(previous :initarg :previous :initform nil :accessor generic-function-previous)
(source :initarg :source :initform nil :accessor generic-function-source)
(closed-p :initarg :closed-p :initform nil :accessor generic-function-closed-p)
)))
#.(create-accessors +standard-generic-function-slots+ 'standard-generic-function)
;;; ----------------------------------------------------------------------
;;; STANDARD-METHOD
(eval-when (compile eval)
(defparameter +standard-method-slots+
'((generic-function :initarg :generic-function :initform nil
:accessor method-generic-function)
(lambda-list :initarg :lambda-list :initform t
:accessor method-lambda-list)
(specializers :initarg :specializers :initform t :accessor method-specializers)
(qualifiers :initarg :qualifiers :initform nil :accessor method-qualifiers)
(function :initarg :function :accessor method-function)
(fun-context-setter :initarg :fun-context-setter :accessor method-fun-context-setter)
(documentation :initarg :documentation :initform nil :accessor method-documentation)
(plist :initarg :plist :initform nil :accessor method-plist)
(version :initarg :version :initform 0 :accessor method-version)
(previous :initarg :previous :initform nil :accessor method-previous)
(source :initarg :source :initform nil :accessor method-source)
)))
#.(create-accessors +standard-method-slots+ 'standard-method)
;;; ----------------------------------------------------------------------
;;;
;;; FIND-CLASS naming classes.
;;;
;;;
;;; (FIND-CLASS <name>) returns the class named <name>. setf can be used
;;; with find-class to set the class named <name>. These are "extrinsic"
;;; names. Neither find-class nor setf of find-class do anything with the
;;; name slot of the class, they only lookup and change the association from
;;; name to class.
;;;
;;; This is only used during boot. The real one is in built-in.
(eval-when (compile)
(defun setf-find-class (new-value class &optional errorp env)
(declare (ignore new-value errorp env))
#+mkcl-bootstrap
(format t "~&;;; Bootstrap note: Ignoring class definition for ~S" class)
#-mkcl-bootstrap
(warn "Ignoring class definition for ~S" class)))
(defun setf-find-class (new-value name &optional errorp env)
(declare (ignore errorp env))
(with-metadata-lock
(let ((old-class (find-class name nil)))
(cond
((and old-class
(or (typep old-class 'built-in-class)
(member name '(class built-in-class) :test #'eq)))
(error "The class associated to the CL specifier ~S cannot be changed." name))
((classp new-value)
(si:set-class-proper-name name new-value))
((null new-value)
(si:set-class-proper-name name nil))
(t (error "~A is not a class." new-value)))))
new-value)
(defsetf find-class (&rest x) (v) `(setf-find-class ,v ,@x))
(defun classp (obj)
(and (si:instancep obj)
(let ((topmost (find-class 'CLASS nil)))
;; All instances can be classes until the class CLASS has
;; been installed. Otherwise, we check the parents.
(or (null topmost)
(si::subclassp (si::instance-class obj) topmost)))
t))
;;; ----------------------------------------------------------------------
;;; Methods
(defun mangle-internal-method-name (name qualifiers specializers)
(let ((name-str (cond ((symbolp name) (symbol-name name))
((consp name) (concatenate 'base-string
"setf-" (symbol-name (cadr name))))
(t (setq name ""))))
qual-str
spec-str
mangled
)
(dolist (qual qualifiers)
(setq qual-str
(concatenate 'base-string
qual-str "_"
(if (symbolp qual)
(symbol-name qual)
"???")))
)
(dolist (spec specializers)
(setq spec-str
(concatenate 'base-string
spec-str "_"
(cond ((null spec) "nil")
((consp spec) "eql")
((si::instancep spec) (symbol-name (class-name spec)))
(t (symbol-name spec)))))
)
(setq mangled name-str)
(when spec-str
(setq mangled (concatenate 'base-string mangled "_" spec-str)))
(when qual-str
(setq mangled (concatenate 'base-string mangled "_" qual-str)))
(let ((internal-name (intern mangled)))
internal-name)
)
)
(defun install-method (name qualifiers specializers lambda-list doc plist fun fun-context-setter
&optional method-class &rest options)
(declare (notinline ensure-generic-function))
(with-metadata-lock
(let* ((gf (ensure-generic-function name :source (getf options :source)))
(internal-name (mangle-internal-method-name name qualifiers specializers))
(specializers (mapcar #'(lambda (x) ;; here class names are turned into class objects.
(cond ((null x) x)
((consp x) x)
((si::instancep x) x)
(t (find-class x))))
specializers))
(method (make-method (or method-class
(generic-function-method-class gf))
qualifiers specializers lambda-list doc
fun fun-context-setter plist options)))
(si:set-compiled-function-name fun internal-name)
(si:set-compiled-function-owner fun method)
(when fun-context-setter (funcall fun-context-setter gf method))
(add-method gf method)
method)))
;;; ----------------------------------------------------------------------
;;; early versions
;;; early version used during bootstrap
(defun ensure-generic-function (name &key (lambda-list (si::unbound) l-l-p) source)
(if (and (fboundp name) (si::instancep (fdefinition name)))
(fdefinition name)
;; create a fake standard-generic-function object:
(let ((gfun (si:allocate-raw-instance nil (find-class 't)
#.(length +standard-generic-function-slots+))))
(declare (type standard-object gfun))
;; create a new gfun
(si::instance-sig-set gfun)
(setf (generic-function-name gfun) name
(generic-function-lambda-list gfun) lambda-list
(generic-function-method-combination gfun) '(standard)
(generic-function-methods gfun) nil
(generic-function-spec-list gfun) nil
(generic-function-method-class gfun) 'standard-method)
(setf (generic-function-documentation gfun) nil
(generic-function-methods gfun) nil
(generic-function-a-p-o-function gfun) nil
(generic-function-version gfun) 0
(generic-function-previous gfun) nil
(generic-function-source gfun) source
(generic-function-closed-p gfun) nil)
(when l-l-p
(setf (generic-function-argument-precedence-order gfun)
(si::process-lambda-list lambda-list t)))
(set-funcallable-instance-function gfun t)
(setf (fdefinition name) gfun)
gfun)))
;;; ----------------------------------------------------------------------
;;; COMPUTE-APPLICABLE-METHODS
;;;
;;; FIXME! This should be split int an internal function, like
;;; raw-compute-... and a higher level interface, because the current
;;; version does not check _any_ of the arguments but it is
;;; nevertheless exported by the ANSI specification!
;;;
(defun compute-applicable-methods (gf args)
(with-metadata-lock
(let* ((methods (generic-function-methods gf))
(f (generic-function-a-p-o-function gf))
applicable-list
args-specializers)
;; first compute the applicable method list
(dolist (method methods)
;; for each method in the list
(do* ((scan-args args (cdr scan-args))
(scan-specializers (method-specializers method)
(cdr scan-specializers))
(arg)
(spec))
;; check if the method is applicable verifying
;; if each argument satisfies the corresponding
;; parameter specializers
((null scan-args) (push method applicable-list))
(setq arg (first scan-args)
spec (first scan-specializers))
(cond ((null spec))
((listp spec)
(unless (eql arg (second spec))
(return)))
((not (si::of-class-p arg spec))
(return)))))
(dolist (arg args)
(push (class-of arg) args-specializers))
(setq args-specializers (nreverse args-specializers))
;; reorder args to match the precedence order
(when f
(setf args-specializers
(funcall f (subseq args-specializers 0
(length (generic-function-argument-precedence-order gf))))))
;; then order the list
(do* ((scan applicable-list)
(most-specific (first scan) (first scan))
(ordered-list))
((null (cdr scan)) (when most-specific
;; at least one method
;;(print (mapcar #'method-specializers
;; (reverse (cons most-specific ordered-list))))
(nreverse
(push most-specific ordered-list))))
(dolist (meth (cdr scan))
(when (eq (compare-methods most-specific
meth args-specializers f) 2)
(setq most-specific meth)))
(setq scan (delete most-specific scan))
(push most-specific ordered-list)))))
;;; ----------------------------------------------------------------------
;;; method comparison
(defun compare-methods (method-1 method-2 args-specializers f)
(let* ((specializers-list-1 (method-specializers method-1))
(specializers-list-2 (method-specializers method-2)))
(compare-specializers-lists (if f (funcall f specializers-list-1) specializers-list-1)
(if f (funcall f specializers-list-2) specializers-list-2)
args-specializers)))
(defun compare-specializers-lists (spec-list-1 spec-list-2 args-specializers)
(when (or spec-list-1 spec-list-2)
(ecase (compare-specializers (first spec-list-1)
(first spec-list-2)
(first args-specializers))
(1 '1)
(2 '2)
(=
(compare-specializers-lists (cdr spec-list-1)
(cdr spec-list-2)
(cdr args-specializers)))
((nil)
(error "The type specifiers ~S and ~S can not be disambiguated~
with respect to the argument specializer: ~S"
(or (car spec-list-1) t)
(or (car spec-list-2) t)
(car args-specializers)))))
)
(defun fast-subtypep (spec1 spec2)
;; Specialized version of subtypep which uses the fact that spec1
;; and spec2 are either classes or of the form (EQL x)
(if (atom spec1)
(if (atom spec2)
(si::subclassp spec1 spec2)
;; There is only one class with a single element, which
;; is NIL = (MEMBER NIL).
(and (null (second spec2))
(eq (class-name (first spec1)) 'nil)))
(if (atom spec2)
(si::of-class-p (second spec1) spec2)
(eql (second spec1) (second spec2)))))
(defun compare-specializers (spec-1 spec-2 arg-class)
(let* ((cpl (class-precedence-list arg-class)))
(cond ((equal spec-1 spec-2) '=)
((null spec-1) '2)
((null spec-2) '1)
((fast-subtypep spec-1 spec-2) '1)
((fast-subtypep spec-2 spec-1) '2)
((and (listp spec-1) (eq (car spec-1) 'eql)) '1) ; is this engough?
((and (listp spec-2) (eq (car spec-2) 'eql)) '2) ; Beppe
((member spec-1 (member spec-2 cpl)) '2)
((member spec-2 (member spec-1 cpl)) '1)
;;(t (error "Complex type specifiers are not yet supported."))
;; This will force an error in the caller
(t nil))))
(defun compute-g-f-spec-list (gf)
(flet ((nupdate-spec-how-list (spec-how-list specializers gf)
;; FIXME! This check should have happened before, shouldn't it???
(let ((l (length specializers)))
(if spec-how-list
(unless (= (length spec-how-list) l)
(error "The generic function ~A~%has ~D required arguments, ~
but the new specialization provides ~D."
gf (length spec-how-list) l))
(setf spec-how-list (make-list l))))
;; update the spec-how of the gfun
;; computing the or of the previous value and the new one
(do* ((l specializers (cdr l))
(l2 spec-how-list (cdr l2))
(spec-how)
(spec-how-old))
((null l))
(setq spec-how (first l) spec-how-old (first l2))
(setf (first l2)
(if (consp spec-how) ; an eql list
(if (consp spec-how-old)
(list* (second spec-how) spec-how-old)
(cdr spec-how))
(if (consp spec-how-old)
spec-how-old
(or spec-how spec-how-old)))))
spec-how-list))
(let* ((spec-how-list nil)
(function nil)
(a-p-o (generic-function-argument-precedence-order gf)))
(dolist (method (generic-function-methods gf))
(setf spec-how-list
(nupdate-spec-how-list spec-how-list (method-specializers method) gf)))
(setf (generic-function-spec-list gf)
(loop for type in spec-how-list
for name in (generic-function-lambda-list gf)
for i from 0
when type collect (cons type
i ;; fix by A. Gavrilov used to be: (position name a-p-o)
)))
(let* ((g-f-l-l (generic-function-lambda-list gf)))
(when (consp g-f-l-l)
(let ((required-arguments (si::process-lambda-list g-f-l-l t)))
(unless (equal a-p-o required-arguments)
(setf function
(coerce `(lambda (%list)
(destructuring-bind ,required-arguments %list
(list ,@a-p-o)))
'function))))))
(setf (generic-function-a-p-o-function gf) function)
(si:clear-gfun-cache gf))))
(defun clear-cached-make-instance (class)
(setf (class-cached-make-instance class) nil)
(dolist (subclass (class-direct-subclasses class))
(clear-cached-make-instance subclass)))
(defun maybe-clear-cached-make-instance (gf method)
(when (case (generic-function-name gf)
((shared-initialize initialize-instance allocate-instance) t)
(t nil))
(clear-cached-make-instance (car (method-specializers method))))
)