1 ;;;; This software is part of the SBCL system. See the README file for
4 ;;;; This software is derived from software originally released by Xerox
5 ;;;; Corporation. Copyright and release statements follow. Later modifications
6 ;;;; to the software are in the public domain and are provided with
7 ;;;; absolutely no warranty. See the COPYING and CREDITS files for more
10 ;;;; copyright information from original PCL sources:
12 ;;;; Copyright (c) 1985, 1986, 1987, 1988, 1989, 1990 Xerox Corporation.
13 ;;;; All rights reserved.
15 ;;;; Use and copying of this software and preparation of derivative works based
16 ;;;; upon this software are permitted. Any distribution of this software or
17 ;;;; derivative works must comply with all applicable United States export
20 ;;;; This software is made available AS IS, and Xerox Corporation makes no
21 ;;;; warranty about the software, its performance or its conformity to any
26 (defmethod slot-accessor-function ((slotd effective-slot-definition) type)
28 (reader (slot-definition-reader-function slotd))
29 (writer (slot-definition-writer-function slotd))
30 (boundp (slot-definition-boundp-function slotd))))
32 (defmethod (setf slot-accessor-function) (function
33 (slotd effective-slot-definition)
36 (reader (setf (slot-definition-reader-function slotd) function))
37 (writer (setf (slot-definition-writer-function slotd) function))
38 (boundp (setf (slot-definition-boundp-function slotd) function))))
40 (defconstant +slotd-reader-function-std-p+ 1)
41 (defconstant +slotd-writer-function-std-p+ 2)
42 (defconstant +slotd-boundp-function-std-p+ 4)
43 (defconstant +slotd-all-function-std-p+ 7)
45 (defmethod slot-accessor-std-p ((slotd effective-slot-definition) type)
46 (let ((flags (slot-value slotd 'accessor-flags)))
47 (declare (type fixnum flags))
49 (eql +slotd-all-function-std-p+ flags)
50 (let ((mask (ecase type
51 (reader +slotd-reader-function-std-p+)
52 (writer +slotd-writer-function-std-p+)
53 (boundp +slotd-boundp-function-std-p+))))
54 (declare (type fixnum mask))
55 (not (zerop (the fixnum (logand mask flags))))))))
57 (defmethod (setf slot-accessor-std-p) (value
58 (slotd effective-slot-definition)
60 (let ((mask (ecase type
61 (reader +slotd-reader-function-std-p+)
62 (writer +slotd-writer-function-std-p+)
63 (boundp +slotd-boundp-function-std-p+)))
64 (flags (slot-value slotd 'accessor-flags)))
65 (declare (type fixnum mask flags))
66 (setf (slot-value slotd 'accessor-flags)
68 (the fixnum (logior mask flags))
69 (the fixnum (logand (the fixnum (lognot mask)) flags)))))
72 (defmethod initialize-internal-slot-functions ((slotd
73 effective-slot-definition))
74 (let* ((name (slot-value slotd 'name))
75 (class (slot-value slotd 'class)))
76 (let ((table (or (gethash name *name->class->slotd-table*)
77 (setf (gethash name *name->class->slotd-table*)
78 (make-hash-table :test 'eq :size 5)))))
79 (setf (gethash class table) slotd))
80 (dolist (type '(reader writer boundp))
81 (let* ((gf-name (ecase type
82 (reader 'slot-value-using-class)
83 (writer '(setf slot-value-using-class))
84 (boundp 'slot-boundp-using-class)))
85 (gf (gdefinition gf-name)))
86 (compute-slot-accessor-info slotd type gf)))
87 (initialize-internal-slot-gfs name)))
89 (defmethod compute-slot-accessor-info ((slotd effective-slot-definition)
91 (let* ((name (slot-value slotd 'name))
92 (class (slot-value slotd 'class))
93 (old-slotd (find-slot-definition class name))
94 (old-std-p (and old-slotd (slot-accessor-std-p old-slotd 'all))))
95 (multiple-value-bind (function std-p)
96 (if (eq *boot-state* 'complete)
97 (get-accessor-method-function gf type class slotd)
98 (get-optimized-std-accessor-method-function class slotd type))
99 (setf (slot-accessor-std-p slotd type) std-p)
100 (setf (slot-accessor-function slotd type) function))
101 (when (and old-slotd (not (eq old-std-p (slot-accessor-std-p slotd 'all))))
102 (push (cons class name) *pv-table-cache-update-info*))))
104 (defmethod slot-definition-allocation ((slotd structure-slot-definition))
107 (defmethod shared-initialize :after ((object documentation-mixin)
109 &key (documentation nil documentation-p))
110 (declare (ignore slot-names))
111 (when documentation-p
112 (setf (plist-value object 'documentation) documentation)))
114 ;;; default if DOC-TYPE doesn't match one of the specified types
115 (defmethod documentation (object doc-type)
116 (warn "unsupported DOCUMENTATION: type ~S for object ~S"
121 ;;; default if DOC-TYPE doesn't match one of the specified types
122 (defmethod (setf documentation) (new-value object doc-type)
123 ;; CMU CL made this an error, but since ANSI says that even for supported
124 ;; doc types an implementation is permitted to discard docs at any time
125 ;; for any reason, this feels to me more like a warning. -- WHN 19991214
126 (warn "discarding unsupported DOCUMENTATION of type ~S for object ~S"
131 (defmethod documentation ((object documentation-mixin) doc-type)
132 (declare (ignore doc-type))
133 (plist-value object 'documentation))
135 (defmethod (setf documentation) (new-value
136 (object documentation-mixin)
138 (declare (ignore doc-type))
139 (setf (plist-value object 'documentation) new-value))
141 (defmethod documentation ((slotd standard-slot-definition) doc-type)
142 (declare (ignore doc-type))
143 (slot-value slotd 'documentation))
145 (defmethod (setf documentation) (new-value
146 (slotd standard-slot-definition)
148 (declare (ignore doc-type))
149 (setf (slot-value slotd 'documentation) new-value))
151 ;;;; various class accessors that are a little more complicated than can be
152 ;;;; done with automatically generated reader methods
154 (defmethod class-finalized-p ((class pcl-class))
155 (with-slots (wrapper) class
156 (not (null wrapper))))
158 (defmethod class-prototype ((class std-class))
159 (with-slots (prototype) class
160 (or prototype (setq prototype (allocate-instance class)))))
162 (defmethod class-prototype ((class structure-class))
163 (with-slots (prototype wrapper defstruct-constructor) class
166 (if defstruct-constructor
167 (allocate-instance class)
168 (allocate-standard-instance wrapper))))))
170 (defmethod class-direct-default-initargs ((class slot-class))
171 (plist-value class 'direct-default-initargs))
173 (defmethod class-default-initargs ((class slot-class))
174 (plist-value class 'default-initargs))
176 (defmethod class-slot-cells ((class std-class))
177 (plist-value class 'class-slot-cells))
179 ;;;; class accessors that are even a little bit more complicated than those
180 ;;;; above. These have a protocol for updating them, we must implement that
183 ;;; Maintaining the direct subclasses backpointers. The update methods are
184 ;;; here, the values are read by an automatically generated reader method.
185 (defmethod add-direct-subclass ((class class) (subclass class))
186 (with-slots (direct-subclasses) class
187 (pushnew subclass direct-subclasses)
189 (defmethod remove-direct-subclass ((class class) (subclass class))
190 (with-slots (direct-subclasses) class
191 (setq direct-subclasses (remove subclass direct-subclasses))
194 ;;; Maintaining the direct-methods and direct-generic-functions backpointers.
196 ;;; There are four generic functions involved, each has one method for the
197 ;;; class case and another method for the damned EQL specializers. All of
198 ;;; these are specified methods and appear in their specified place in the
201 ;;; ADD-DIRECT-METHOD
202 ;;; REMOVE-DIRECT-METHOD
203 ;;; SPECIALIZER-DIRECT-METHODS
204 ;;; SPECIALIZER-DIRECT-GENERIC-FUNCTIONS
206 ;;; In each case, we maintain one value which is a cons. The car is the list
207 ;;; methods. The cdr is a list of the generic functions. The cdr is always
209 (defmethod add-direct-method ((specializer class) (method method))
210 (with-slots (direct-methods) specializer
211 (setf (car direct-methods) (adjoin method (car direct-methods)) ;PUSH
212 (cdr direct-methods) ()))
214 (defmethod remove-direct-method ((specializer class) (method method))
215 (with-slots (direct-methods) specializer
216 (setf (car direct-methods) (remove method (car direct-methods))
217 (cdr direct-methods) ()))
220 (defmethod specializer-direct-methods ((specializer class))
221 (with-slots (direct-methods) specializer
222 (car direct-methods)))
224 (defmethod specializer-direct-generic-functions ((specializer class))
225 (with-slots (direct-methods) specializer
226 (or (cdr direct-methods)
227 (setf (cdr direct-methods)
229 (dolist (m (car direct-methods))
230 ;; the old PCL code used COLLECTING-ONCE which used
231 ;; #'EQ to check for newness
232 (pushnew (method-generic-function m) collect :test #'eq))
233 (nreverse collect))))))
235 ;;; This hash table is used to store the direct methods and direct generic
236 ;;; functions of EQL specializers. Each value in the table is the cons.
237 (defvar *eql-specializer-methods* (make-hash-table :test 'eql))
238 (defvar *class-eq-specializer-methods* (make-hash-table :test 'eq))
240 (defmethod specializer-method-table ((specializer eql-specializer))
241 *eql-specializer-methods*)
243 (defmethod specializer-method-table ((specializer class-eq-specializer))
244 *class-eq-specializer-methods*)
246 (defmethod add-direct-method ((specializer specializer-with-object)
248 (let* ((object (specializer-object specializer))
249 (table (specializer-method-table specializer))
250 (entry (gethash object table)))
253 (setf (gethash object table)
255 (setf (car entry) (adjoin method (car entry))
259 (defmethod remove-direct-method ((specializer specializer-with-object)
261 (let* ((object (specializer-object specializer))
262 (entry (gethash object (specializer-method-table specializer))))
264 (setf (car entry) (remove method (car entry))
268 (defmethod specializer-direct-methods ((specializer specializer-with-object))
269 (car (gethash (specializer-object specializer)
270 (specializer-method-table specializer))))
272 (defmethod specializer-direct-generic-functions ((specializer
273 specializer-with-object))
274 (let* ((object (specializer-object specializer))
275 (entry (gethash object (specializer-method-table specializer))))
280 (dolist (m (car entry))
281 (pushnew (method-generic-function m) collect :test #'eq))
282 (nreverse collect)))))))
284 (defun map-specializers (function)
285 (map-all-classes (lambda (class)
286 (funcall function (class-eq-specializer class))
287 (funcall function class)))
288 (maphash (lambda (object methods)
289 (declare (ignore methods))
290 (intern-eql-specializer object))
291 *eql-specializer-methods*)
292 (maphash (lambda (object specl)
293 (declare (ignore object))
294 (funcall function specl))
295 *eql-specializer-table*)
298 (defun map-all-generic-functions (function)
299 (let ((all-generic-functions (make-hash-table :test 'eq)))
300 (map-specializers (lambda (specl)
301 (dolist (gf (specializer-direct-generic-functions
303 (unless (gethash gf all-generic-functions)
304 (setf (gethash gf all-generic-functions) t)
305 (funcall function gf))))))
308 (defmethod shared-initialize :after ((specl class-eq-specializer)
311 (declare (ignore slot-names))
312 (setf (slot-value specl 'type) `(class-eq ,(specializer-class specl))))
314 (defmethod shared-initialize :after ((specl eql-specializer) slot-names &key)
315 (declare (ignore slot-names))
316 (setf (slot-value specl 'type) `(eql ,(specializer-object specl))))
318 (defun real-load-defclass (name metaclass-name supers slots other)
319 (let ((res (apply #'ensure-class name :metaclass metaclass-name
320 :direct-superclasses supers
322 :definition-source `((defclass ,name)
325 ;; Defclass of a class with a forward-referenced superclass does not
326 ;; have a wrapper. RES is the incomplete PCL class. The Lisp class
327 ;; does not yet exist. Maybe should return NIL in that case as RES
328 ;; is not useful to the user?
329 (and (class-wrapper res) (sb-kernel:layout-class (class-wrapper res)))))
331 (setf (gdefinition 'load-defclass) #'real-load-defclass)
333 (defun ensure-class (name &rest all)
334 (apply #'ensure-class-using-class name (find-class name nil) all))
336 (defmethod ensure-class-using-class (name (class null) &rest args &key)
337 (multiple-value-bind (meta initargs)
338 (ensure-class-values class args)
339 (setf class (apply #'make-instance meta :name name initargs)
340 (find-class name) class)
343 (defmethod ensure-class-using-class (name (class pcl-class) &rest args &key)
344 (multiple-value-bind (meta initargs)
345 (ensure-class-values class args)
346 (unless (eq (class-of class) meta) (change-class class meta))
347 (apply #'reinitialize-instance class initargs)
348 (setf (find-class name) class)
351 (defmethod class-predicate-name ((class t))
356 ((not (legal-class-name-p s))
357 (error "~S is not a class or a legal class name." s))
359 (or (find-class s nil)
361 (make-instance 'forward-referenced-class
364 (defun ensure-class-values (class args)
365 (let* ((initargs (copy-list args))
366 (unsupplied (list 1))
367 (supplied-meta (getf initargs :metaclass unsupplied))
368 (supplied-supers (getf initargs :direct-superclasses unsupplied))
369 (supplied-slots (getf initargs :direct-slots unsupplied))
371 (cond ((neq supplied-meta unsupplied)
372 (find-class supplied-meta))
374 (forward-referenced-class-p class))
375 *the-class-standard-class*)
378 ;; KLUDGE: It seemed to me initially that there ought to be a way
379 ;; of collecting all the erroneous problems in one go, rather than
380 ;; this way of solving the problem of signalling the errors that
381 ;; we are required to, which stops at the first bogus input.
382 ;; However, after playing around a little, I couldn't find that
383 ;; way, so I've left it as is, but if someone does come up with a
384 ;; better way... -- CSR, 2002-09-08
385 (do ((direct-slots (getf initargs :direct-slots) (cdr direct-slots)))
386 ((endp direct-slots) nil)
387 (destructuring-bind (slot &rest more) direct-slots
388 (let ((slot-name (getf slot :name)))
389 (when (some (lambda (s) (eq slot-name (getf s :name))) more)
390 ;; FIXME: It's quite possible that we ought to define an
391 ;; SB-INT:PROGRAM-ERROR function to signal these and other
392 ;; errors throughout the codebase that are required to be
393 ;; of type PROGRAM-ERROR.
394 (error 'simple-program-error
395 :format-control "~@<There is more than one direct slot ~
397 :format-arguments (list slot-name)))
398 (do ((stuff slot (cddr stuff)))
400 (destructuring-bind (option value &rest more) stuff
402 ((and (member option '(:allocation :type
403 :initform :documentation))
405 (getf more option unsupplied))))
406 (error 'simple-program-error
407 :format-control "~@<Duplicate slot option ~S for ~
409 :format-arguments (list option slot-name)))
410 ((and (eq option :readers)
411 (notevery #'symbolp value))
412 (error 'simple-program-error
413 :format-control "~@<Slot reader names for slot ~
414 named ~S must be symbols.~:>"
415 :format-arguments (list slot-name)))
416 ((and (eq option :initargs)
417 (notevery #'symbolp value))
418 (error 'simple-program-error
419 :format-control "~@<Slot initarg names for slot ~
420 named ~S must be symbols.~:>"
421 :format-arguments (list slot-name)))))))))
422 (loop for (initarg . more) on (getf initargs :direct-default-initargs)
423 for name = (car initarg)
424 when (some (lambda (a) (eq (car a) name)) more)
425 do (error 'simple-program-error
426 :format-control "~@<Duplicate initialization argument ~
427 name ~S in :DEFAULT-INITARGS.~:>"
428 :format-arguments (list name class)))
430 (default-initargs 0))
431 (do ((args initargs (cddr args)))
435 (when (> (incf metaclass) 1)
436 (error 'simple-program-error
437 :format-control "~@<More than one :METACLASS ~
438 option specified.~:>")))
439 (:direct-default-initargs
440 (when (> (incf default-initargs) 1)
441 (error 'simple-program-error
442 :format-control "~@<More than one :DEFAULT-INITARGS ~
443 option specified.~:>"))))))
444 (remf initargs :metaclass)
445 (loop (unless (remf initargs :direct-superclasses) (return)))
446 (loop (unless (remf initargs :direct-slots) (return)))
448 (list* :direct-superclasses
449 (and (neq supplied-supers unsupplied)
450 (mapcar #'fix-super supplied-supers))
452 (and (neq supplied-slots unsupplied) supplied-slots)
456 (defmethod shared-initialize :after
459 &key (direct-superclasses nil direct-superclasses-p)
460 (direct-slots nil direct-slots-p)
461 (direct-default-initargs nil direct-default-initargs-p)
462 (predicate-name nil predicate-name-p))
463 (declare (ignore slot-names))
464 (cond (direct-superclasses-p
465 (setq direct-superclasses
466 (or direct-superclasses
467 (list (if (funcallable-standard-class-p class)
468 *the-class-funcallable-standard-object*
469 *the-class-standard-object*))))
470 (dolist (superclass direct-superclasses)
471 (unless (validate-superclass class superclass)
472 (error "The class ~S was specified as a~%
473 super-class of the class ~S;~%~
474 but the meta-classes ~S and~%~S are incompatible.~@
475 Define a method for ~S to avoid this error."
476 superclass class (class-of superclass) (class-of class)
477 'validate-superclass)))
478 (setf (slot-value class 'direct-superclasses) direct-superclasses))
480 (setq direct-superclasses (slot-value class 'direct-superclasses))))
483 (setf (slot-value class 'direct-slots)
484 (mapcar (lambda (pl) (make-direct-slotd class pl))
486 (slot-value class 'direct-slots)))
487 (if direct-default-initargs-p
488 (setf (plist-value class 'direct-default-initargs)
489 direct-default-initargs)
490 (setq direct-default-initargs
491 (plist-value class 'direct-default-initargs)))
492 (setf (plist-value class 'class-slot-cells)
494 (dolist (dslotd direct-slots)
495 (when (eq :class (slot-definition-allocation dslotd))
496 (let ((initfunction (slot-definition-initfunction dslotd)))
497 (push (cons (slot-definition-name dslotd)
499 (funcall initfunction)
503 (setq predicate-name (if predicate-name-p
504 (setf (slot-value class 'predicate-name)
505 (car predicate-name))
506 (or (slot-value class 'predicate-name)
507 (setf (slot-value class 'predicate-name)
508 (make-class-predicate-name (class-name
510 (add-direct-subclasses class direct-superclasses)
511 (update-class class nil)
512 (make-class-predicate class predicate-name)
513 (add-slot-accessors class direct-slots))
515 (defmethod shared-initialize :before ((class class) slot-names &key name)
516 (declare (ignore slot-names name))
517 ;; FIXME: Could this just be CLASS instead of `(CLASS ,CLASS)? If not,
518 ;; why not? (See also similar expression in !BOOTSTRAP-INITIALIZE-CLASS.)
519 (setf (slot-value class 'type) `(class ,class))
520 (setf (slot-value class 'class-eq-specializer)
521 (make-instance 'class-eq-specializer :class class)))
523 (defmethod reinitialize-instance :before ((class slot-class) &key)
524 (remove-direct-subclasses class (class-direct-superclasses class))
525 (remove-slot-accessors class (class-direct-slots class)))
527 (defmethod reinitialize-instance :after ((class slot-class)
530 (map-dependents class
532 (apply #'update-dependent class dependent initargs))))
534 (defmethod shared-initialize :after
535 ((slotd structure-slot-definition) slot-names &key
536 (allocation :instance) allocation-class)
537 (declare (ignore slot-names allocation-class))
538 (unless (eq allocation :instance)
539 (error "Structure slots must have :INSTANCE allocation.")))
541 (defun make-structure-class-defstruct-form (name direct-slots include)
542 (let* ((conc-name (intern (format nil "~S structure class " name)))
543 (constructor (intern (format nil "~Aconstructor" conc-name)))
544 (defstruct `(defstruct (,name
546 `((:include ,(class-name include))))
548 (:conc-name ,conc-name)
549 (:constructor ,constructor ())
551 ,@(mapcar (lambda (slot)
552 `(,(slot-definition-name slot)
555 (reader-names (mapcar (lambda (slotd)
559 (slot-definition-name
562 (writer-names (mapcar (lambda (slotd)
566 (slot-definition-name
570 (mapcar (lambda (slotd reader-name)
572 (slot-definition-defstruct-accessor-symbol
574 `(defun ,reader-name (obj)
575 (declare (type ,name obj))
577 direct-slots reader-names))
579 (mapcar (lambda (slotd writer-name)
581 (slot-definition-defstruct-accessor-symbol
583 `(defun ,writer-name (nv obj)
584 (declare (type ,name obj))
585 (setf (,accessor obj) nv))))
586 direct-slots writer-names))
590 ,@readers-init ,@writers-init
592 (values defstruct-form constructor reader-names writer-names)))
594 (defmethod shared-initialize :after
595 ((class structure-class)
597 &key (direct-superclasses nil direct-superclasses-p)
598 (direct-slots nil direct-slots-p)
599 direct-default-initargs
600 (predicate-name nil predicate-name-p))
601 (declare (ignore slot-names direct-default-initargs))
602 (if direct-superclasses-p
603 (setf (slot-value class 'direct-superclasses)
604 (or direct-superclasses
605 (setq direct-superclasses
606 (and (not (eq (class-name class) 'structure-object))
607 (list *the-class-structure-object*)))))
608 (setq direct-superclasses (slot-value class 'direct-superclasses)))
609 (let* ((name (class-name class))
610 (from-defclass-p (slot-value class 'from-defclass-p))
611 (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
613 (setf (slot-value class 'direct-slots)
617 (let* ((slot-name (getf pl :name))
620 "~S structure class ~A"
622 (accessor (intern acc-name)))
623 (setq pl (list* :defstruct-accessor-symbol
625 (make-direct-slotd class pl))
627 (setq direct-slots (slot-value class 'direct-slots)))
629 (let ((include (car (slot-value class 'direct-superclasses))))
630 (multiple-value-bind (defstruct-form constructor reader-names writer-names)
631 (make-structure-class-defstruct-form name direct-slots include)
632 (unless (structure-type-p name) (eval defstruct-form))
633 (mapc (lambda (dslotd reader-name writer-name)
634 (let* ((reader (gdefinition reader-name))
635 (writer (when (gboundp writer-name)
636 (gdefinition writer-name))))
637 (setf (slot-value dslotd 'internal-reader-function)
639 (setf (slot-value dslotd 'internal-writer-function)
641 direct-slots reader-names writer-names)
642 (setf (slot-value class 'defstruct-form) defstruct-form)
643 (setf (slot-value class 'defstruct-constructor) constructor))))
644 (add-direct-subclasses class direct-superclasses)
645 (setf (slot-value class 'class-precedence-list)
646 (compute-class-precedence-list class))
647 (setf (slot-value class 'slots) (compute-slots class))
648 (let ((lclass (cl:find-class (class-name class))))
649 (setf (sb-kernel:class-pcl-class lclass) class)
650 (setf (slot-value class 'wrapper) (sb-kernel:class-layout lclass)))
651 (update-pv-table-cache-info class)
652 (setq predicate-name (if predicate-name-p
653 (setf (slot-value class 'predicate-name)
654 (car predicate-name))
655 (or (slot-value class 'predicate-name)
656 (setf (slot-value class 'predicate-name)
657 (make-class-predicate-name
658 (class-name class))))))
659 (make-class-predicate class predicate-name)
660 (add-slot-accessors class direct-slots)))
662 (defmethod direct-slot-definition-class ((class structure-class) initargs)
663 (declare (ignore initargs))
664 (find-class 'structure-direct-slot-definition))
666 (defmethod finalize-inheritance ((class structure-class))
667 nil) ; always finalized
669 (defun add-slot-accessors (class dslotds)
670 (fix-slot-accessors class dslotds 'add))
672 (defun remove-slot-accessors (class dslotds)
673 (fix-slot-accessors class dslotds 'remove))
675 (defun fix-slot-accessors (class dslotds add/remove)
676 (flet ((fix (gfspec name r/w)
677 (let ((gf (ensure-generic-function gfspec)))
679 (r (if (eq add/remove 'add)
680 (add-reader-method class gf name)
681 (remove-reader-method class gf)))
682 (w (if (eq add/remove 'add)
683 (add-writer-method class gf name)
684 (remove-writer-method class gf)))))))
685 (dolist (dslotd dslotds)
686 (let ((slot-name (slot-definition-name dslotd)))
687 (dolist (r (slot-definition-readers dslotd)) (fix r slot-name 'r))
688 (dolist (w (slot-definition-writers dslotd)) (fix w slot-name 'w))))))
690 (defun add-direct-subclasses (class supers)
691 (dolist (super supers)
692 (unless (memq class (class-direct-subclasses class))
693 (add-direct-subclass super class))))
695 (defun remove-direct-subclasses (class supers)
696 (let ((old (class-direct-superclasses class)))
697 (dolist (o (set-difference old supers))
698 (remove-direct-subclass o class))))
700 (defmethod finalize-inheritance ((class std-class))
701 (update-class class t))
703 (defmethod finalize-inheritance ((class forward-referenced-class))
704 ;; FIXME: should we not be thinking a bit about what kinds of error
705 ;; we're throwing? Maybe we need a clos-error type to mix in? Or
706 ;; possibly a forward-referenced-class-error, though that's
707 ;; difficult given e.g. class precedence list calculations...
709 "~@<FINALIZE-INHERITANCE was called on a forward referenced class:~
714 (defun class-has-a-forward-referenced-superclass-p (class)
715 (or (forward-referenced-class-p class)
716 (some #'class-has-a-forward-referenced-superclass-p
717 (class-direct-superclasses class))))
719 ;;; This is called by :after shared-initialize whenever a class is initialized
720 ;;; or reinitialized. The class may or may not be finalized.
721 (defun update-class (class finalizep)
722 ;; Comment from Gerd Moellmann:
724 ;; Note that we can't simply delay the finalization when CLASS has
725 ;; no forward referenced superclasses because that causes bootstrap
727 (when (and (not finalizep)
728 (not (class-finalized-p class))
729 (not (class-has-a-forward-referenced-superclass-p class)))
730 (finalize-inheritance class)
731 (return-from update-class))
732 (when (or finalizep (class-finalized-p class)
733 (not (class-has-a-forward-referenced-superclass-p class)))
734 (update-cpl class (compute-class-precedence-list class))
735 ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
736 ;; class. The hoops above are to ensure that FINALIZE-INHERITANCE
737 ;; is called at finalization, so that MOP programmers can hook
738 ;; into the system as described in "Class Finalization Protocol"
739 ;; (section 5.5.2 of AMOP).
740 (update-slots class (compute-slots class))
741 (update-gfs-of-class class)
742 (update-inits class (compute-default-initargs class))
743 (update-ctors 'finalize-inheritance :class class))
745 (dolist (sub (class-direct-subclasses class)) (update-class sub nil))))
747 (defun update-cpl (class cpl)
748 (if (class-finalized-p class)
749 (unless (equal (class-precedence-list class) cpl)
750 ;; comment from the old CMU CL sources:
751 ;; Need to have the cpl setup before update-lisp-class-layout
752 ;; is called on CMU CL.
753 (setf (slot-value class 'class-precedence-list) cpl)
754 (force-cache-flushes class))
755 (setf (slot-value class 'class-precedence-list) cpl))
756 (update-class-can-precede-p cpl))
758 (defun update-class-can-precede-p (cpl)
760 (let ((first (car cpl)))
761 (dolist (c (cdr cpl))
762 (pushnew c (slot-value first 'can-precede-list))))
763 (update-class-can-precede-p (cdr cpl))))
765 (defun class-can-precede-p (class1 class2)
766 (member class2 (class-can-precede-list class1)))
768 (defun update-slots (class eslotds)
769 (let ((instance-slots ())
771 (dolist (eslotd eslotds)
772 (let ((alloc (slot-definition-allocation eslotd)))
774 (:instance (push eslotd instance-slots))
775 (:class (push eslotd class-slots)))))
777 ;; If there is a change in the shape of the instances then the
778 ;; old class is now obsolete.
779 (let* ((nlayout (mapcar #'slot-definition-name
780 (sort instance-slots #'<
781 :key #'slot-definition-location)))
782 (nslots (length nlayout))
783 (nwrapper-class-slots (compute-class-slots class-slots))
784 (owrapper (class-wrapper class))
785 (olayout (and owrapper (wrapper-instance-slots-layout owrapper)))
786 (owrapper-class-slots (and owrapper (wrapper-class-slots owrapper)))
788 (cond ((null owrapper)
789 (make-wrapper nslots class))
790 ((and (equal nlayout olayout)
792 (loop for o in owrapper-class-slots
793 for n in nwrapper-class-slots
794 do (unless (eq (car o) (car n)) (return t)))))
797 ;; This will initialize the new wrapper to have the
798 ;; same state as the old wrapper. We will then have
799 ;; to change that. This may seem like wasted work
800 ;; (and it is), but the spec requires that we call
801 ;; MAKE-INSTANCES-OBSOLETE.
802 (make-instances-obsolete class)
803 (class-wrapper class)))))
805 (with-slots (wrapper slots) class
806 (update-lisp-class-layout class nwrapper)
808 (wrapper-instance-slots-layout nwrapper) nlayout
809 (wrapper-class-slots nwrapper) nwrapper-class-slots
810 (wrapper-no-of-instance-slots nwrapper) nslots
813 (unless (eq owrapper nwrapper)
814 (update-pv-table-cache-info class)))))
816 (defun compute-class-slots (eslotds)
818 (dolist (eslotd eslotds)
819 (push (assoc (slot-definition-name eslotd)
820 (class-slot-cells (slot-definition-class eslotd)))
824 (defun update-gfs-of-class (class)
825 (when (and (class-finalized-p class)
826 (let ((cpl (class-precedence-list class)))
827 (or (member *the-class-slot-class* cpl)
828 (member *the-class-standard-effective-slot-definition*
830 (let ((gf-table (make-hash-table :test 'eq)))
831 (labels ((collect-gfs (class)
832 (dolist (gf (specializer-direct-generic-functions class))
833 (setf (gethash gf gf-table) t))
834 (mapc #'collect-gfs (class-direct-superclasses class))))
836 (maphash (lambda (gf ignore)
837 (declare (ignore ignore))
838 (update-gf-dfun class gf))
841 (defun update-inits (class inits)
842 (setf (plist-value class 'default-initargs) inits))
844 (defmethod compute-default-initargs ((class slot-class))
845 (let ((cpl (class-precedence-list class))
846 (direct (class-direct-default-initargs class)))
847 (labels ((walk (tail)
850 (let ((c (pop tail)))
851 (append (if (eq c class)
853 (class-direct-default-initargs c))
855 (let ((initargs (walk cpl)))
856 (delete-duplicates initargs :test #'eq :key #'car :from-end t)))))
858 ;;;; protocols for constructing direct and effective slot definitions
860 (defmethod direct-slot-definition-class ((class std-class) initargs)
861 (declare (ignore initargs))
862 (find-class 'standard-direct-slot-definition))
864 (defun make-direct-slotd (class initargs)
865 (let ((initargs (list* :class class initargs)))
866 (apply #'make-instance
867 (direct-slot-definition-class class initargs)
870 (defmethod compute-slots ((class std-class))
871 ;; As specified, we must call COMPUTE-EFFECTIVE-SLOT-DEFINITION once
872 ;; for each different slot name we find in our superclasses. Each
873 ;; call receives the class and a list of the dslotds with that name.
874 ;; The list is in most-specific-first order.
875 (let ((name-dslotds-alist ()))
876 (dolist (c (class-precedence-list class))
877 (dolist (slot (class-direct-slots c))
878 (let* ((name (slot-definition-name slot))
879 (entry (assq name name-dslotds-alist)))
881 (push slot (cdr entry))
882 (push (list name slot) name-dslotds-alist)))))
883 (mapcar (lambda (direct)
884 (compute-effective-slot-definition class
885 (nreverse (cdr direct))))
886 name-dslotds-alist)))
888 (defmethod compute-slots ((class standard-class))
891 (defmethod compute-slots :around ((class standard-class))
892 (let ((eslotds (call-next-method))
894 (dolist (eslotd eslotds eslotds)
895 (setf (slot-definition-location eslotd)
896 (ecase (slot-definition-allocation eslotd)
900 (let* ((name (slot-definition-name eslotd))
901 (from-class (slot-definition-allocation-class eslotd))
902 (cell (assq name (class-slot-cells from-class))))
905 (initialize-internal-slot-functions eslotd))))
907 (defmethod compute-slots ((class funcallable-standard-class))
910 (defmethod compute-slots :around ((class funcallable-standard-class))
911 (labels ((instance-slot-names (slotds)
913 (dolist (slotd slotds (nreverse collect))
914 (when (eq (slot-definition-allocation slotd) :instance)
915 (push (slot-definition-name slotd) collect)))))
916 ;; This sorts slots so that slots of classes later in the CPL
917 ;; come before slots of other classes. This is crucial for
918 ;; funcallable instances because it ensures that the slots of
919 ;; FUNCALLABLE-STANDARD-OBJECT, which includes the slots of
920 ;; KERNEL:FUNCALLABLE-INSTANCE, come first, which in turn
921 ;; makes it possible to treat FUNCALLABLE-STANDARD-OBJECT as
922 ;; a funcallable instance.
923 (compute-layout (eslotds)
925 (names (instance-slot-names eslotds)))
927 (reverse (class-precedence-list class))
928 (nreverse (nconc names first)))
929 (dolist (ss (class-slots class))
930 (let ((name (slot-definition-name ss)))
931 (when (member name names)
933 (setq names (delete name names)))))))))
934 (let ((all-slotds (call-next-method))
937 (dolist (slotd all-slotds)
938 (ecase (slot-definition-allocation slotd)
939 (:instance (push slotd instance-slots))
940 (:class (push slotd class-slots))))
941 (let ((layout (compute-layout instance-slots)))
942 (dolist (slotd instance-slots)
943 (setf (slot-definition-location slotd)
944 (position (slot-definition-name slotd) layout))
945 (initialize-internal-slot-functions slotd)))
946 (dolist (slotd class-slots)
947 (let ((name (slot-definition-name slotd))
948 (from-class (slot-definition-allocation-class slotd)))
949 (setf (slot-definition-location slotd)
950 (assoc name (class-slot-cells from-class)))
951 (aver (consp (slot-definition-location slotd)))
952 (initialize-internal-slot-functions slotd)))
955 (defmethod compute-slots ((class structure-class))
956 (mapcan (lambda (superclass)
957 (mapcar (lambda (dslotd)
958 (compute-effective-slot-definition class
960 (class-direct-slots superclass)))
961 (reverse (slot-value class 'class-precedence-list))))
963 (defmethod compute-slots :around ((class structure-class))
964 (let ((eslotds (call-next-method)))
965 (mapc #'initialize-internal-slot-functions eslotds)
968 (defmethod compute-effective-slot-definition ((class slot-class) dslotds)
969 (let* ((initargs (compute-effective-slot-definition-initargs class dslotds))
970 (class (effective-slot-definition-class class initargs)))
971 (apply #'make-instance class initargs)))
973 (defmethod effective-slot-definition-class ((class std-class) initargs)
974 (declare (ignore initargs))
975 (find-class 'standard-effective-slot-definition))
977 (defmethod effective-slot-definition-class ((class structure-class) initargs)
978 (declare (ignore initargs))
979 (find-class 'structure-effective-slot-definition))
981 (defmethod compute-effective-slot-definition-initargs
982 ((class slot-class) direct-slotds)
988 (allocation-class nil)
994 (dolist (slotd direct-slotds)
997 (setq name (slot-definition-name slotd)
1000 (when (slot-definition-initfunction slotd)
1001 (setq initform (slot-definition-initform slotd)
1002 initfunction (slot-definition-initfunction slotd)
1005 (setq allocation (slot-definition-allocation slotd)
1006 allocation-class (slot-definition-class slotd)
1008 (setq initargs (append (slot-definition-initargs slotd) initargs))
1009 (let ((slotd-type (slot-definition-type slotd)))
1010 (setq type (cond ((eq type t) slotd-type)
1011 ((*subtypep type slotd-type) type)
1012 (t `(and ,type ,slotd-type)))))))
1015 :initfunction initfunction
1017 :allocation allocation
1018 :allocation-class allocation-class
1022 (defmethod compute-effective-slot-definition-initargs :around
1023 ((class structure-class) direct-slotds)
1024 (let ((slotd (car direct-slotds)))
1025 (list* :defstruct-accessor-symbol
1026 (slot-definition-defstruct-accessor-symbol slotd)
1027 :internal-reader-function
1028 (slot-definition-internal-reader-function slotd)
1029 :internal-writer-function
1030 (slot-definition-internal-writer-function slotd)
1031 (call-next-method))))
1033 ;;; NOTE: For bootstrapping considerations, these can't use MAKE-INSTANCE
1034 ;;; to make the method object. They have to use make-a-method which
1035 ;;; is a specially bootstrapped mechanism for making standard methods.
1036 (defmethod reader-method-class ((class slot-class) direct-slot &rest initargs)
1037 (declare (ignore direct-slot initargs))
1038 (find-class 'standard-reader-method))
1040 (defmethod add-reader-method ((class slot-class) generic-function slot-name)
1041 (add-method generic-function
1042 (make-a-method 'standard-reader-method
1044 (list (or (class-name class) 'object))
1046 (make-reader-method-function class slot-name)
1047 "automatically generated reader method"
1050 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
1051 (declare (ignore direct-slot initargs))
1052 (find-class 'standard-writer-method))
1054 (defmethod add-writer-method ((class slot-class) generic-function slot-name)
1055 (add-method generic-function
1056 (make-a-method 'standard-writer-method
1058 (list 'new-value (or (class-name class) 'object))
1059 (list *the-class-t* class)
1060 (make-writer-method-function class slot-name)
1061 "automatically generated writer method"
1064 (defmethod add-boundp-method ((class slot-class) generic-function slot-name)
1065 (add-method generic-function
1066 (make-a-method 'standard-boundp-method
1068 (list (or (class-name class) 'object))
1070 (make-boundp-method-function class slot-name)
1071 "automatically generated boundp method"
1074 (defmethod remove-reader-method ((class slot-class) generic-function)
1075 (let ((method (get-method generic-function () (list class) nil)))
1076 (when method (remove-method generic-function method))))
1078 (defmethod remove-writer-method ((class slot-class) generic-function)
1080 (get-method generic-function () (list *the-class-t* class) nil)))
1081 (when method (remove-method generic-function method))))
1083 (defmethod remove-boundp-method ((class slot-class) generic-function)
1084 (let ((method (get-method generic-function () (list class) nil)))
1085 (when method (remove-method generic-function method))))
1087 ;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITE-METHOD function are NOT
1088 ;;; part of the standard protocol. They are however useful, PCL makes
1089 ;;; use of them internally and documents them for PCL users.
1091 ;;; *** This needs work to make type testing by the writer functions which
1092 ;;; *** do type testing faster. The idea would be to have one constructor
1093 ;;; *** for each possible type test.
1095 ;;; *** There is a subtle bug here which is going to have to be fixed.
1096 ;;; *** Namely, the simplistic use of the template has to be fixed. We
1097 ;;; *** have to give the OPTIMIZE-SLOT-VALUE method the user might have
1098 ;;; *** defined for this metaclass a chance to run.
1100 (defmethod make-reader-method-function ((class slot-class) slot-name)
1101 (make-std-reader-method-function (class-name class) slot-name))
1103 (defmethod make-writer-method-function ((class slot-class) slot-name)
1104 (make-std-writer-method-function (class-name class) slot-name))
1106 (defmethod make-boundp-method-function ((class slot-class) slot-name)
1107 (make-std-boundp-method-function (class-name class) slot-name))
1109 (defmethod compatible-meta-class-change-p (class proto-new-class)
1110 (eq (class-of class) (class-of proto-new-class)))
1112 (defmethod validate-superclass ((class class) (new-super class))
1113 (or (eq new-super *the-class-t*)
1114 (eq (class-of class) (class-of new-super))))
1116 (defmethod validate-superclass ((class standard-class) (new-super std-class))
1117 (let ((new-super-meta-class (class-of new-super)))
1118 (or (eq new-super-meta-class *the-class-std-class*)
1119 (eq (class-of class) new-super-meta-class))))
1121 ;;; What this does depends on which of the four possible values of
1122 ;;; LAYOUT-INVALID the PCL wrapper has; the simplest case is when it
1123 ;;; is (:FLUSH <wrapper>) or (:OBSOLETE <wrapper>), when there is
1124 ;;; nothing to do, as the new wrapper has already been created. If
1125 ;;; LAYOUT-INVALID returns NIL, then we invalidate it (setting it to
1126 ;;; (:FLUSH <wrapper>); UPDATE-SLOTS later gets to choose whether or
1127 ;;; not to "upgrade" this to (:OBSOLETE <wrapper>).
1129 ;;; This leaves the case where LAYOUT-INVALID returns T, which happens
1130 ;;; when REGISTER-LAYOUT has invalidated a superclass of CLASS (which
1131 ;;; invalidated all the subclasses in SB-KERNEL land). Again, here we
1132 ;;; must flush the caches and allow UPDATE-SLOTS to decide whether to
1133 ;;; obsolete the wrapper.
1135 ;;; FIXME: either here or in INVALID-WRAPPER-P looks like a good place
1136 ;;; for (AVER (NOT (EQ (SB-KERNEL:LAYOUT-INVALID OWRAPPER)
1137 ;;; :UNINITIALIZED)))
1139 ;;; Thanks to Gerd Moellmann for the explanation. -- CSR, 2002-10-29
1140 (defun force-cache-flushes (class)
1141 (let* ((owrapper (class-wrapper class)))
1142 ;; We only need to do something if the wrapper is still valid. If
1143 ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
1144 ;; both of those will already be doing what we want. In
1145 ;; particular, we must be sure we never change an OBSOLETE into a
1146 ;; FLUSH since OBSOLETE means do what FLUSH does and then some.
1147 (when (or (not (invalid-wrapper-p owrapper))
1148 ;; KLUDGE: despite the observations above, this remains
1149 ;; a violation of locality or what might be considered
1150 ;; good style. There has to be a better way! -- CSR,
1152 (eq (sb-kernel:layout-invalid owrapper) t))
1153 (let ((nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1155 (setf (wrapper-instance-slots-layout nwrapper)
1156 (wrapper-instance-slots-layout owrapper))
1157 (setf (wrapper-class-slots nwrapper)
1158 (wrapper-class-slots owrapper))
1159 (sb-sys:without-interrupts
1160 (update-lisp-class-layout class nwrapper)
1161 (setf (slot-value class 'wrapper) nwrapper)
1162 (invalidate-wrapper owrapper :flush nwrapper))))))
1164 (defun flush-cache-trap (owrapper nwrapper instance)
1165 (declare (ignore owrapper))
1166 (set-wrapper instance nwrapper))
1168 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
1169 ;;; the next access to the instance (as defined in 88-002R) to trap
1170 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
1171 (defmethod make-instances-obsolete ((class std-class))
1172 (let* ((owrapper (class-wrapper class))
1173 (nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1175 (setf (wrapper-instance-slots-layout nwrapper)
1176 (wrapper-instance-slots-layout owrapper))
1177 (setf (wrapper-class-slots nwrapper)
1178 (wrapper-class-slots owrapper))
1179 (sb-sys:without-interrupts
1180 (update-lisp-class-layout class nwrapper)
1181 (setf (slot-value class 'wrapper) nwrapper)
1182 (invalidate-wrapper owrapper :obsolete nwrapper)
1185 (defmethod make-instances-obsolete ((class symbol))
1186 (make-instances-obsolete (find-class class)))
1188 ;;; OBSOLETE-INSTANCE-TRAP is the internal trap that is called when we
1189 ;;; see an obsolete instance. The times when it is called are:
1190 ;;; - when the instance is involved in method lookup
1191 ;;; - when attempting to access a slot of an instance
1193 ;;; It is not called by class-of, wrapper-of, or any of the low-level
1194 ;;; instance access macros.
1196 ;;; Of course these times when it is called are an internal
1197 ;;; implementation detail of PCL and are not part of the documented
1198 ;;; description of when the obsolete instance update happens. The
1199 ;;; documented description is as it appears in 88-002R.
1201 ;;; This has to return the new wrapper, so it counts on all the
1202 ;;; methods on obsolete-instance-trap-internal to return the new
1203 ;;; wrapper. It also does a little internal error checking to make
1204 ;;; sure that the traps are only happening when they should, and that
1205 ;;; the trap methods are computing appropriate new wrappers.
1207 ;;; OBSOLETE-INSTANCE-TRAP might be called on structure instances
1208 ;;; after a structure is redefined. In most cases,
1209 ;;; OBSOLETE-INSTANCE-TRAP will not be able to fix the old instance,
1210 ;;; so it must signal an error. The hard part of this is that the
1211 ;;; error system and debugger might cause OBSOLETE-INSTANCE-TRAP to be
1212 ;;; called again, so in that case, we have to return some reasonable
1213 ;;; wrapper, instead.
1215 (defvar *in-obsolete-instance-trap* nil)
1216 (defvar *the-wrapper-of-structure-object*
1217 (class-wrapper (find-class 'structure-object)))
1219 (define-condition obsolete-structure (error)
1220 ((datum :reader obsolete-structure-datum :initarg :datum))
1222 (lambda (condition stream)
1223 ;; Don't try to print the structure, since it probably won't work.
1225 "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
1226 (type-of (obsolete-structure-datum condition))))))
1228 (defun obsolete-instance-trap (owrapper nwrapper instance)
1229 (if (not (pcl-instance-p instance))
1230 (if *in-obsolete-instance-trap*
1231 *the-wrapper-of-structure-object*
1232 (let ((*in-obsolete-instance-trap* t))
1233 (error 'obsolete-structure :datum instance)))
1234 (let* ((class (wrapper-class* nwrapper))
1235 (copy (allocate-instance class)) ;??? allocate-instance ???
1236 (olayout (wrapper-instance-slots-layout owrapper))
1237 (nlayout (wrapper-instance-slots-layout nwrapper))
1238 (oslots (get-slots instance))
1239 (nslots (get-slots copy))
1240 (oclass-slots (wrapper-class-slots owrapper))
1244 ;; local --> local transfer
1245 ;; local --> shared discard
1246 ;; local --> -- discard
1247 ;; shared --> local transfer
1248 ;; shared --> shared discard
1249 ;; shared --> -- discard
1253 ;; Go through all the old local slots.
1255 (dolist (name olayout)
1256 (let ((npos (posq name nlayout)))
1258 (setf (clos-slots-ref nslots npos)
1259 (clos-slots-ref oslots opos))
1261 (push name discarded)
1262 (unless (eq (clos-slots-ref oslots opos) +slot-unbound+)
1263 (setf (getf plist name) (clos-slots-ref oslots opos))))))
1266 ;; Go through all the old shared slots.
1267 (dolist (oclass-slot-and-val oclass-slots)
1268 (let ((name (car oclass-slot-and-val))
1269 (val (cdr oclass-slot-and-val)))
1270 (let ((npos (posq name nlayout)))
1272 (setf (clos-slots-ref nslots npos) (cdr oclass-slot-and-val))
1273 (progn (push name discarded)
1274 (unless (eq val +slot-unbound+)
1275 (setf (getf plist name) val)))))))
1277 ;; Go through all the new local slots to compute the added slots.
1278 (dolist (nlocal nlayout)
1279 (unless (or (memq nlocal olayout)
1280 (assq nlocal oclass-slots))
1281 (push nlocal added)))
1283 (swap-wrappers-and-slots instance copy)
1285 (update-instance-for-redefined-class instance
1291 (defun change-class-internal (instance new-class initargs)
1292 (let* ((old-class (class-of instance))
1293 (copy (allocate-instance new-class))
1294 (new-wrapper (get-wrapper copy))
1295 (old-wrapper (class-wrapper old-class))
1296 (old-layout (wrapper-instance-slots-layout old-wrapper))
1297 (new-layout (wrapper-instance-slots-layout new-wrapper))
1298 (old-slots (get-slots instance))
1299 (new-slots (get-slots copy))
1300 (old-class-slots (wrapper-class-slots old-wrapper)))
1302 ;; "The values of local slots specified by both the class CTO and
1303 ;; CFROM are retained. If such a local slot was unbound, it
1304 ;; remains unbound."
1305 (let ((new-position 0))
1306 (dolist (new-slot new-layout)
1307 (let ((old-position (posq new-slot old-layout)))
1309 (setf (clos-slots-ref new-slots new-position)
1310 (clos-slots-ref old-slots old-position))))
1311 (incf new-position)))
1313 ;; "The values of slots specified as shared in the class CFROM and
1314 ;; as local in the class CTO are retained."
1315 (dolist (slot-and-val old-class-slots)
1316 (let ((position (posq (car slot-and-val) new-layout)))
1318 (setf (clos-slots-ref new-slots position) (cdr slot-and-val)))))
1320 ;; Make the copy point to the old instance's storage, and make the
1321 ;; old instance point to the new storage.
1322 (swap-wrappers-and-slots instance copy)
1324 (apply #'update-instance-for-different-class copy instance initargs)
1327 (defmethod change-class ((instance standard-object)
1328 (new-class standard-class)
1330 (change-class-internal instance new-class initargs))
1332 (defmethod change-class ((instance funcallable-standard-object)
1333 (new-class funcallable-standard-class)
1335 (change-class-internal instance new-class initargs))
1337 (defmethod change-class ((instance standard-object)
1338 (new-class funcallable-standard-class)
1340 (declare (ignore initargs))
1341 (error "You can't change the class of ~S to ~S~@
1342 because it isn't already an instance with metaclass ~S."
1343 instance new-class 'standard-class))
1345 (defmethod change-class ((instance funcallable-standard-object)
1346 (new-class standard-class)
1348 (declare (ignore initargs))
1349 (error "You can't change the class of ~S to ~S~@
1350 because it isn't already an instance with metaclass ~S."
1351 instance new-class 'funcallable-standard-class))
1353 (defmethod change-class ((instance t) (new-class-name symbol) &rest initargs)
1354 (apply #'change-class instance (find-class new-class-name) initargs))
1356 ;;;; The metaclass BUILT-IN-CLASS
1358 ;;;; This metaclass is something of a weird creature. By this point, all
1359 ;;;; instances of it which will exist have been created, and no instance
1360 ;;;; is ever created by calling MAKE-INSTANCE.
1362 ;;;; But, there are other parts of the protocol we must follow and those
1363 ;;;; definitions appear here.
1365 (defmethod shared-initialize :before
1366 ((class built-in-class) slot-names &rest initargs)
1367 (declare (ignore slot-names initargs))
1368 (error "attempt to initialize or reinitialize a built in class"))
1370 (defmethod class-direct-slots ((class built-in-class)) ())
1371 (defmethod class-slots ((class built-in-class)) ())
1372 (defmethod class-direct-default-initargs ((class built-in-class)) ())
1373 (defmethod class-default-initargs ((class built-in-class)) ())
1375 (defmethod validate-superclass ((c class) (s built-in-class))
1376 (or (eq s *the-class-t*)
1377 (eq s *the-class-stream*)))
1379 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
1380 (defmethod class-direct-slots ((class forward-referenced-class)) ())
1381 (defmethod class-direct-default-initargs ((class forward-referenced-class)) ())
1382 (macrolet ((def (method)
1383 `(defmethod ,method ((class forward-referenced-class))
1384 (error "~@<~I~S was called on a forward referenced class:~2I~_~S~:>"
1386 (def class-default-initargs)
1387 (def class-precedence-list)
1390 (defmethod validate-superclass ((c slot-class)
1391 (f forward-referenced-class))
1394 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
1395 (pushnew dependent (plist-value metaobject 'dependents)))
1397 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
1398 (setf (plist-value metaobject 'dependents)
1399 (delete dependent (plist-value metaobject 'dependents))))
1401 (defmethod map-dependents ((metaobject dependent-update-mixin) function)
1402 (dolist (dependent (plist-value metaobject 'dependents))
1403 (funcall function dependent)))