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 (loop for (slot . more) on (getf initargs :direct-slots)
386 for slot-name = (getf slot :name)
387 if (some (lambda (s) (eq slot-name (getf s :name))) more)
388 ;; FIXME: It's quite possible that we ought to define an
389 ;; SB-INT:PROGRAM-ERROR function to signal these and other
390 ;; errors throughout the code base that are required to be
391 ;; of type PROGRAM-ERROR.
392 do (error 'simple-program-error
393 :format-control "More than one direct slot with name ~S."
394 :format-arguments (list slot-name))
396 do (loop for (option value . more) on slot by #'cddr
397 when (and (member option
399 :initform :documentation))
401 (getf more option unsupplied))))
402 do (error 'simple-program-error
403 :format-control "Duplicate slot option ~S for slot ~S."
404 :format-arguments (list option slot-name))))
405 (loop for (initarg . more) on (getf initargs :direct-default-initargs)
406 for name = (car initarg)
407 when (some (lambda (a) (eq (car a) name)) more)
408 do (error 'simple-program-error
409 :format-control "Duplicate initialization argument ~
410 name ~S in :default-initargs of class ~A."
411 :format-arguments (list name class)))
412 (loop (unless (remf initargs :metaclass) (return)))
413 (loop (unless (remf initargs :direct-superclasses) (return)))
414 (loop (unless (remf initargs :direct-slots) (return)))
416 (list* :direct-superclasses
417 (and (neq supplied-supers unsupplied)
418 (mapcar #'fix-super supplied-supers))
420 (and (neq supplied-slots unsupplied) supplied-slots)
424 (defmethod shared-initialize :after
427 &key (direct-superclasses nil direct-superclasses-p)
428 (direct-slots nil direct-slots-p)
429 (direct-default-initargs nil direct-default-initargs-p)
430 (predicate-name nil predicate-name-p))
431 (declare (ignore slot-names))
432 (cond (direct-superclasses-p
433 (setq direct-superclasses
434 (or direct-superclasses
435 (list (if (funcallable-standard-class-p class)
436 *the-class-funcallable-standard-object*
437 *the-class-standard-object*))))
438 (dolist (superclass direct-superclasses)
439 (unless (validate-superclass class superclass)
440 (error "The class ~S was specified as a~%
441 super-class of the class ~S;~%~
442 but the meta-classes ~S and~%~S are incompatible.~@
443 Define a method for ~S to avoid this error."
444 superclass class (class-of superclass) (class-of class)
445 'validate-superclass)))
446 (setf (slot-value class 'direct-superclasses) direct-superclasses))
448 (setq direct-superclasses (slot-value class 'direct-superclasses))))
451 (setf (slot-value class 'direct-slots)
452 (mapcar (lambda (pl) (make-direct-slotd class pl))
454 (slot-value class 'direct-slots)))
455 (if direct-default-initargs-p
456 (setf (plist-value class 'direct-default-initargs)
457 direct-default-initargs)
458 (setq direct-default-initargs
459 (plist-value class 'direct-default-initargs)))
460 (setf (plist-value class 'class-slot-cells)
462 (dolist (dslotd direct-slots)
463 (when (eq :class (slot-definition-allocation dslotd))
464 (let ((initfunction (slot-definition-initfunction dslotd)))
465 (push (cons (slot-definition-name dslotd)
467 (funcall initfunction)
471 (setq predicate-name (if predicate-name-p
472 (setf (slot-value class 'predicate-name)
473 (car predicate-name))
474 (or (slot-value class 'predicate-name)
475 (setf (slot-value class 'predicate-name)
476 (make-class-predicate-name (class-name
478 (add-direct-subclasses class direct-superclasses)
479 (update-class class nil)
480 (make-class-predicate class predicate-name)
481 (add-slot-accessors class direct-slots))
483 (defmethod shared-initialize :before ((class class) slot-names &key name)
484 (declare (ignore slot-names name))
485 ;; FIXME: Could this just be CLASS instead of `(CLASS ,CLASS)? If not,
486 ;; why not? (See also similar expression in !BOOTSTRAP-INITIALIZE-CLASS.)
487 (setf (slot-value class 'type) `(class ,class))
488 (setf (slot-value class 'class-eq-specializer)
489 (make-instance 'class-eq-specializer :class class)))
491 (defmethod reinitialize-instance :before ((class slot-class) &key)
492 (remove-direct-subclasses class (class-direct-superclasses class))
493 (remove-slot-accessors class (class-direct-slots class)))
495 (defmethod reinitialize-instance :after ((class slot-class)
498 (map-dependents class
500 (apply #'update-dependent class dependent initargs))))
502 (defmethod shared-initialize :after
503 ((slotd structure-slot-definition) slot-names &key
504 (allocation :instance) allocation-class)
505 (declare (ignore slot-names allocation-class))
506 (unless (eq allocation :instance)
507 (error "Structure slots must have :INSTANCE allocation.")))
509 (defun make-structure-class-defstruct-form (name direct-slots include)
510 (let* ((conc-name (intern (format nil "~S structure class " name)))
511 (constructor (intern (format nil "~Aconstructor" conc-name)))
512 (defstruct `(defstruct (,name
514 `((:include ,(class-name include))))
516 (:conc-name ,conc-name)
517 (:constructor ,constructor ())
519 ,@(mapcar (lambda (slot)
520 `(,(slot-definition-name slot)
523 (reader-names (mapcar (lambda (slotd)
527 (slot-definition-name
530 (writer-names (mapcar (lambda (slotd)
534 (slot-definition-name
538 (mapcar (lambda (slotd reader-name)
540 (slot-definition-defstruct-accessor-symbol
542 `(defun ,reader-name (obj)
543 (declare (type ,name obj))
545 direct-slots reader-names))
547 (mapcar (lambda (slotd writer-name)
549 (slot-definition-defstruct-accessor-symbol
551 `(defun ,writer-name (nv obj)
552 (declare (type ,name obj))
553 (setf (,accessor obj) nv))))
554 direct-slots writer-names))
558 ,@readers-init ,@writers-init
560 (values defstruct-form constructor reader-names writer-names)))
562 (defmethod shared-initialize :after
563 ((class structure-class)
565 &key (direct-superclasses nil direct-superclasses-p)
566 (direct-slots nil direct-slots-p)
567 direct-default-initargs
568 (predicate-name nil predicate-name-p))
569 (declare (ignore slot-names direct-default-initargs))
570 (if direct-superclasses-p
571 (setf (slot-value class 'direct-superclasses)
572 (or direct-superclasses
573 (setq direct-superclasses
574 (and (not (eq (class-name class) 'structure-object))
575 (list *the-class-structure-object*)))))
576 (setq direct-superclasses (slot-value class 'direct-superclasses)))
577 (let* ((name (class-name class))
578 (from-defclass-p (slot-value class 'from-defclass-p))
579 (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
581 (setf (slot-value class 'direct-slots)
585 (let* ((slot-name (getf pl :name))
588 "~S structure class ~A"
590 (accessor (intern acc-name)))
591 (setq pl (list* :defstruct-accessor-symbol
593 (make-direct-slotd class pl))
595 (setq direct-slots (slot-value class 'direct-slots)))
597 (let ((include (car (slot-value class 'direct-superclasses))))
598 (multiple-value-bind (defstruct-form constructor reader-names writer-names)
599 (make-structure-class-defstruct-form name direct-slots include)
600 (unless (structure-type-p name) (eval defstruct-form))
601 (mapc (lambda (dslotd reader-name writer-name)
602 (let* ((reader (gdefinition reader-name))
603 (writer (when (gboundp writer-name)
604 (gdefinition writer-name))))
605 (setf (slot-value dslotd 'internal-reader-function)
607 (setf (slot-value dslotd 'internal-writer-function)
609 direct-slots reader-names writer-names)
610 (setf (slot-value class 'defstruct-form) defstruct-form)
611 (setf (slot-value class 'defstruct-constructor) constructor))))
612 (add-direct-subclasses class direct-superclasses)
613 (setf (slot-value class 'class-precedence-list)
614 (compute-class-precedence-list class))
615 (setf (slot-value class 'slots) (compute-slots class))
616 (let ((lclass (cl:find-class (class-name class))))
617 (setf (sb-kernel:class-pcl-class lclass) class)
618 (setf (slot-value class 'wrapper) (sb-kernel:class-layout lclass)))
619 (update-pv-table-cache-info class)
620 (setq predicate-name (if predicate-name-p
621 (setf (slot-value class 'predicate-name)
622 (car predicate-name))
623 (or (slot-value class 'predicate-name)
624 (setf (slot-value class 'predicate-name)
625 (make-class-predicate-name
626 (class-name class))))))
627 (make-class-predicate class predicate-name)
628 (add-slot-accessors class direct-slots)))
630 (defmethod direct-slot-definition-class ((class structure-class) initargs)
631 (declare (ignore initargs))
632 (find-class 'structure-direct-slot-definition))
634 (defmethod finalize-inheritance ((class structure-class))
635 nil) ; always finalized
637 (defun add-slot-accessors (class dslotds)
638 (fix-slot-accessors class dslotds 'add))
640 (defun remove-slot-accessors (class dslotds)
641 (fix-slot-accessors class dslotds 'remove))
643 (defun fix-slot-accessors (class dslotds add/remove)
644 (flet ((fix (gfspec name r/w)
645 (let ((gf (ensure-generic-function gfspec)))
647 (r (if (eq add/remove 'add)
648 (add-reader-method class gf name)
649 (remove-reader-method class gf)))
650 (w (if (eq add/remove 'add)
651 (add-writer-method class gf name)
652 (remove-writer-method class gf)))))))
653 (dolist (dslotd dslotds)
654 (let ((slot-name (slot-definition-name dslotd)))
655 (dolist (r (slot-definition-readers dslotd)) (fix r slot-name 'r))
656 (dolist (w (slot-definition-writers dslotd)) (fix w slot-name 'w))))))
658 (defun add-direct-subclasses (class supers)
659 (dolist (super supers)
660 (unless (memq class (class-direct-subclasses class))
661 (add-direct-subclass super class))))
663 (defun remove-direct-subclasses (class supers)
664 (let ((old (class-direct-superclasses class)))
665 (dolist (o (set-difference old supers))
666 (remove-direct-subclass o class))))
668 (defmethod finalize-inheritance ((class std-class))
669 (update-class class t))
671 (defmethod finalize-inheritance ((class forward-referenced-class))
672 ;; FIXME: should we not be thinking a bit about what kinds of error
673 ;; we're throwing? Maybe we need a clos-error type to mix in? Or
674 ;; possibly a forward-referenced-class-error, though that's
675 ;; difficult given e.g. class precedence list calculations...
677 "~@<FINALIZE-INHERITANCE was called on a forward referenced class:~
682 (defun class-has-a-forward-referenced-superclass-p (class)
683 (or (forward-referenced-class-p class)
684 (some #'class-has-a-forward-referenced-superclass-p
685 (class-direct-superclasses class))))
687 ;;; This is called by :after shared-initialize whenever a class is initialized
688 ;;; or reinitialized. The class may or may not be finalized.
689 (defun update-class (class finalizep)
690 ;; Comment from Gerd Moellmann:
692 ;; Note that we can't simply delay the finalization when CLASS has
693 ;; no forward referenced superclasses because that causes bootstrap
695 (when (and (not finalizep)
696 (not (class-finalized-p class))
697 (not (class-has-a-forward-referenced-superclass-p class)))
698 (finalize-inheritance class)
699 (return-from update-class))
700 (when (or finalizep (class-finalized-p class)
701 (not (class-has-a-forward-referenced-superclass-p class)))
702 (update-cpl class (compute-class-precedence-list class))
703 ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
704 ;; class. The hoops above are to ensure that FINALIZE-INHERITANCE
705 ;; is called at finalization, so that MOP programmers can hook
706 ;; into the system as described in "Class Finalization Protocol"
707 ;; (section 5.5.2 of AMOP).
708 (update-slots class (compute-slots class))
709 (update-gfs-of-class class)
710 (update-inits class (compute-default-initargs class))
711 (update-make-instance-function-table class))
713 (dolist (sub (class-direct-subclasses class)) (update-class sub nil))))
715 (defun update-cpl (class cpl)
716 (if (class-finalized-p class)
717 (unless (equal (class-precedence-list class) cpl)
718 ;; comment from the old CMU CL sources:
719 ;; Need to have the cpl setup before update-lisp-class-layout
720 ;; is called on CMU CL.
721 (setf (slot-value class 'class-precedence-list) cpl)
722 (force-cache-flushes class))
723 (setf (slot-value class 'class-precedence-list) cpl))
724 (update-class-can-precede-p cpl))
726 (defun update-class-can-precede-p (cpl)
728 (let ((first (car cpl)))
729 (dolist (c (cdr cpl))
730 (pushnew c (slot-value first 'can-precede-list))))
731 (update-class-can-precede-p (cdr cpl))))
733 (defun class-can-precede-p (class1 class2)
734 (member class2 (class-can-precede-list class1)))
736 (defun update-slots (class eslotds)
737 (let ((instance-slots ())
739 (dolist (eslotd eslotds)
740 (let ((alloc (slot-definition-allocation eslotd)))
742 (:instance (push eslotd instance-slots))
743 (:class (push eslotd class-slots)))))
745 ;; If there is a change in the shape of the instances then the
746 ;; old class is now obsolete.
747 (let* ((nlayout (mapcar #'slot-definition-name
748 (sort instance-slots #'<
749 :key #'slot-definition-location)))
750 (nslots (length nlayout))
751 (nwrapper-class-slots (compute-class-slots class-slots))
752 (owrapper (class-wrapper class))
753 (olayout (and owrapper (wrapper-instance-slots-layout owrapper)))
754 (owrapper-class-slots (and owrapper (wrapper-class-slots owrapper)))
756 (cond ((null owrapper)
757 (make-wrapper nslots class))
758 ((and (equal nlayout olayout)
760 (loop for o in owrapper-class-slots
761 for n in nwrapper-class-slots
762 do (unless (eq (car o) (car n)) (return t)))))
765 ;; This will initialize the new wrapper to have the
766 ;; same state as the old wrapper. We will then have
767 ;; to change that. This may seem like wasted work
768 ;; (and it is), but the spec requires that we call
769 ;; MAKE-INSTANCES-OBSOLETE.
770 (make-instances-obsolete class)
771 (class-wrapper class)))))
773 (with-slots (wrapper slots) class
774 (update-lisp-class-layout class nwrapper)
776 (wrapper-instance-slots-layout nwrapper) nlayout
777 (wrapper-class-slots nwrapper) nwrapper-class-slots
778 (wrapper-no-of-instance-slots nwrapper) nslots
781 (unless (eq owrapper nwrapper)
782 (update-pv-table-cache-info class)))))
784 (defun compute-class-slots (eslotds)
786 (dolist (eslotd eslotds)
787 (push (assoc (slot-definition-name eslotd)
788 (class-slot-cells (slot-definition-class eslotd)))
792 (defun update-gfs-of-class (class)
793 (when (and (class-finalized-p class)
794 (let ((cpl (class-precedence-list class)))
795 (or (member *the-class-slot-class* cpl)
796 (member *the-class-standard-effective-slot-definition*
798 (let ((gf-table (make-hash-table :test 'eq)))
799 (labels ((collect-gfs (class)
800 (dolist (gf (specializer-direct-generic-functions class))
801 (setf (gethash gf gf-table) t))
802 (mapc #'collect-gfs (class-direct-superclasses class))))
804 (maphash (lambda (gf ignore)
805 (declare (ignore ignore))
806 (update-gf-dfun class gf))
809 (defun update-inits (class inits)
810 (setf (plist-value class 'default-initargs) inits))
812 (defmethod compute-default-initargs ((class slot-class))
813 (let ((cpl (class-precedence-list class))
814 (direct (class-direct-default-initargs class)))
815 (labels ((walk (tail)
818 (let ((c (pop tail)))
819 (append (if (eq c class)
821 (class-direct-default-initargs c))
823 (let ((initargs (walk cpl)))
824 (delete-duplicates initargs :test #'eq :key #'car :from-end t)))))
826 ;;;; protocols for constructing direct and effective slot definitions
828 (defmethod direct-slot-definition-class ((class std-class) initargs)
829 (declare (ignore initargs))
830 (find-class 'standard-direct-slot-definition))
832 (defun make-direct-slotd (class initargs)
833 (let ((initargs (list* :class class initargs)))
834 (apply #'make-instance
835 (direct-slot-definition-class class initargs)
838 (defmethod compute-slots ((class std-class))
839 ;; As specified, we must call COMPUTE-EFFECTIVE-SLOT-DEFINITION once
840 ;; for each different slot name we find in our superclasses. Each
841 ;; call receives the class and a list of the dslotds with that name.
842 ;; The list is in most-specific-first order.
843 (let ((name-dslotds-alist ()))
844 (dolist (c (class-precedence-list class))
845 (dolist (slot (class-direct-slots c))
846 (let* ((name (slot-definition-name slot))
847 (entry (assq name name-dslotds-alist)))
849 (push slot (cdr entry))
850 (push (list name slot) name-dslotds-alist)))))
851 (mapcar (lambda (direct)
852 (compute-effective-slot-definition class
853 (nreverse (cdr direct))))
854 name-dslotds-alist)))
856 (defmethod compute-slots ((class standard-class))
859 (defmethod compute-slots :around ((class standard-class))
860 (let ((eslotds (call-next-method))
862 (dolist (eslotd eslotds eslotds)
863 (setf (slot-definition-location eslotd)
864 (ecase (slot-definition-allocation eslotd)
868 (let* ((name (slot-definition-name eslotd))
869 (from-class (slot-definition-allocation-class eslotd))
870 (cell (assq name (class-slot-cells from-class))))
873 (initialize-internal-slot-functions eslotd))))
875 (defmethod compute-slots ((class funcallable-standard-class))
878 (defmethod compute-slots :around ((class funcallable-standard-class))
879 (labels ((instance-slot-names (slotds)
881 (dolist (slotd slotds (nreverse collect))
882 (when (eq (slot-definition-allocation slotd) :instance)
883 (push (slot-definition-name slotd) collect)))))
884 ;; This sorts slots so that slots of classes later in the CPL
885 ;; come before slots of other classes. This is crucial for
886 ;; funcallable instances because it ensures that the slots of
887 ;; FUNCALLABLE-STANDARD-OBJECT, which includes the slots of
888 ;; KERNEL:FUNCALLABLE-INSTANCE, come first, which in turn
889 ;; makes it possible to treat FUNCALLABLE-STANDARD-OBJECT as
890 ;; a funcallable instance.
891 (compute-layout (eslotds)
893 (names (instance-slot-names eslotds)))
895 (reverse (class-precedence-list class))
896 (nreverse (nconc names first)))
897 (dolist (ss (class-slots class))
898 (let ((name (slot-definition-name ss)))
899 (when (member name names)
901 (setq names (delete name names)))))))))
902 (let ((all-slotds (call-next-method))
905 (dolist (slotd all-slotds)
906 (ecase (slot-definition-allocation slotd)
907 (:instance (push slotd instance-slots))
908 (:class (push slotd class-slots))))
909 (let ((layout (compute-layout instance-slots)))
910 (dolist (slotd instance-slots)
911 (setf (slot-definition-location slotd)
912 (position (slot-definition-name slotd) layout))
913 (initialize-internal-slot-functions slotd)))
914 (dolist (slotd class-slots)
915 (let ((name (slot-definition-name slotd))
916 (from-class (slot-definition-allocation-class slotd)))
917 (setf (slot-definition-location slotd)
918 (assoc name (class-slot-cells from-class)))
919 (aver (consp (slot-definition-location slotd)))
920 (initialize-internal-slot-functions slotd)))
923 (defmethod compute-slots ((class structure-class))
924 (mapcan (lambda (superclass)
925 (mapcar (lambda (dslotd)
926 (compute-effective-slot-definition class
928 (class-direct-slots superclass)))
929 (reverse (slot-value class 'class-precedence-list))))
931 (defmethod compute-slots :around ((class structure-class))
932 (let ((eslotds (call-next-method)))
933 (mapc #'initialize-internal-slot-functions eslotds)
936 (defmethod compute-effective-slot-definition ((class slot-class) dslotds)
937 (let* ((initargs (compute-effective-slot-definition-initargs class dslotds))
938 (class (effective-slot-definition-class class initargs)))
939 (apply #'make-instance class initargs)))
941 (defmethod effective-slot-definition-class ((class std-class) initargs)
942 (declare (ignore initargs))
943 (find-class 'standard-effective-slot-definition))
945 (defmethod effective-slot-definition-class ((class structure-class) initargs)
946 (declare (ignore initargs))
947 (find-class 'structure-effective-slot-definition))
949 (defmethod compute-effective-slot-definition-initargs
950 ((class slot-class) direct-slotds)
956 (allocation-class nil)
962 (dolist (slotd direct-slotds)
965 (setq name (slot-definition-name slotd)
968 (when (slot-definition-initfunction slotd)
969 (setq initform (slot-definition-initform slotd)
970 initfunction (slot-definition-initfunction slotd)
973 (setq allocation (slot-definition-allocation slotd)
974 allocation-class (slot-definition-class slotd)
976 (setq initargs (append (slot-definition-initargs slotd) initargs))
977 (let ((slotd-type (slot-definition-type slotd)))
978 (setq type (cond ((eq type t) slotd-type)
979 ((*subtypep type slotd-type) type)
980 (t `(and ,type ,slotd-type)))))))
983 :initfunction initfunction
985 :allocation allocation
986 :allocation-class allocation-class
990 (defmethod compute-effective-slot-definition-initargs :around
991 ((class structure-class) direct-slotds)
992 (let ((slotd (car direct-slotds)))
993 (list* :defstruct-accessor-symbol
994 (slot-definition-defstruct-accessor-symbol slotd)
995 :internal-reader-function
996 (slot-definition-internal-reader-function slotd)
997 :internal-writer-function
998 (slot-definition-internal-writer-function slotd)
999 (call-next-method))))
1001 ;;; NOTE: For bootstrapping considerations, these can't use MAKE-INSTANCE
1002 ;;; to make the method object. They have to use make-a-method which
1003 ;;; is a specially bootstrapped mechanism for making standard methods.
1004 (defmethod reader-method-class ((class slot-class) direct-slot &rest initargs)
1005 (declare (ignore direct-slot initargs))
1006 (find-class 'standard-reader-method))
1008 (defmethod add-reader-method ((class slot-class) generic-function slot-name)
1009 (add-method generic-function
1010 (make-a-method 'standard-reader-method
1012 (list (or (class-name class) 'object))
1014 (make-reader-method-function class slot-name)
1015 "automatically generated reader method"
1018 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
1019 (declare (ignore direct-slot initargs))
1020 (find-class 'standard-writer-method))
1022 (defmethod add-writer-method ((class slot-class) generic-function slot-name)
1023 (add-method generic-function
1024 (make-a-method 'standard-writer-method
1026 (list 'new-value (or (class-name class) 'object))
1027 (list *the-class-t* class)
1028 (make-writer-method-function class slot-name)
1029 "automatically generated writer method"
1032 (defmethod add-boundp-method ((class slot-class) generic-function slot-name)
1033 (add-method generic-function
1034 (make-a-method 'standard-boundp-method
1036 (list (or (class-name class) 'object))
1038 (make-boundp-method-function class slot-name)
1039 "automatically generated boundp method"
1042 (defmethod remove-reader-method ((class slot-class) generic-function)
1043 (let ((method (get-method generic-function () (list class) nil)))
1044 (when method (remove-method generic-function method))))
1046 (defmethod remove-writer-method ((class slot-class) generic-function)
1048 (get-method generic-function () (list *the-class-t* class) nil)))
1049 (when method (remove-method generic-function method))))
1051 (defmethod remove-boundp-method ((class slot-class) generic-function)
1052 (let ((method (get-method generic-function () (list class) nil)))
1053 (when method (remove-method generic-function method))))
1055 ;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITE-METHOD function are NOT
1056 ;;; part of the standard protocol. They are however useful, PCL makes
1057 ;;; use of them internally and documents them for PCL users.
1059 ;;; *** This needs work to make type testing by the writer functions which
1060 ;;; *** do type testing faster. The idea would be to have one constructor
1061 ;;; *** for each possible type test.
1063 ;;; *** There is a subtle bug here which is going to have to be fixed.
1064 ;;; *** Namely, the simplistic use of the template has to be fixed. We
1065 ;;; *** have to give the OPTIMIZE-SLOT-VALUE method the user might have
1066 ;;; *** defined for this metaclass a chance to run.
1068 (defmethod make-reader-method-function ((class slot-class) slot-name)
1069 (make-std-reader-method-function (class-name class) slot-name))
1071 (defmethod make-writer-method-function ((class slot-class) slot-name)
1072 (make-std-writer-method-function (class-name class) slot-name))
1074 (defmethod make-boundp-method-function ((class slot-class) slot-name)
1075 (make-std-boundp-method-function (class-name class) slot-name))
1077 (defmethod compatible-meta-class-change-p (class proto-new-class)
1078 (eq (class-of class) (class-of proto-new-class)))
1080 (defmethod validate-superclass ((class class) (new-super class))
1081 (or (eq new-super *the-class-t*)
1082 (eq (class-of class) (class-of new-super))))
1084 (defmethod validate-superclass ((class standard-class) (new-super std-class))
1085 (let ((new-super-meta-class (class-of new-super)))
1086 (or (eq new-super-meta-class *the-class-std-class*)
1087 (eq (class-of class) new-super-meta-class))))
1089 ;;; What this does depends on which of the four possible values of
1090 ;;; LAYOUT-INVALID the PCL wrapper has; the simplest case is when it
1091 ;;; is (:FLUSH <wrapper>) or (:OBSOLETE <wrapper>), when there is
1092 ;;; nothing to do, as the new wrapper has already been created. If
1093 ;;; LAYOUT-INVALID returns NIL, then we invalidate it (setting it to
1094 ;;; (:FLUSH <wrapper>); UPDATE-SLOTS later gets to choose whether or
1095 ;;; not to "upgrade" this to (:OBSOLETE <wrapper>).
1097 ;;; This leaves the case where LAYOUT-INVALID returns T, which happens
1098 ;;; when REGISTER-LAYOUT has invalidated a superclass of CLASS (which
1099 ;;; invalidated all the subclasses in SB-KERNEL land). Again, here we
1100 ;;; must flush the caches and allow UPDATE-SLOTS to decide whether to
1101 ;;; obsolete the wrapper.
1103 ;;; FIXME: either here or in INVALID-WRAPPER-P looks like a good place
1104 ;;; for (AVER (NOT (EQ (SB-KERNEL:LAYOUT-INVALID OWRAPPER)
1105 ;;; :UNINITIALIZED)))
1107 ;;; Thanks to Gerd Moellmann for the explanation. -- CSR, 2002-10-29
1108 (defun force-cache-flushes (class)
1109 (let* ((owrapper (class-wrapper class)))
1110 ;; We only need to do something if the wrapper is still valid. If
1111 ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
1112 ;; both of those will already be doing what we want. In
1113 ;; particular, we must be sure we never change an OBSOLETE into a
1114 ;; FLUSH since OBSOLETE means do what FLUSH does and then some.
1115 (when (or (not (invalid-wrapper-p owrapper))
1116 ;; KLUDGE: despite the observations above, this remains
1117 ;; a violation of locality or what might be considered
1118 ;; good style. There has to be a better way! -- CSR,
1120 (eq (sb-kernel:layout-invalid owrapper) t))
1121 (let ((nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1123 (setf (wrapper-instance-slots-layout nwrapper)
1124 (wrapper-instance-slots-layout owrapper))
1125 (setf (wrapper-class-slots nwrapper)
1126 (wrapper-class-slots owrapper))
1127 (sb-sys:without-interrupts
1128 (update-lisp-class-layout class nwrapper)
1129 (setf (slot-value class 'wrapper) nwrapper)
1130 (invalidate-wrapper owrapper :flush nwrapper))))))
1132 (defun flush-cache-trap (owrapper nwrapper instance)
1133 (declare (ignore owrapper))
1134 (set-wrapper instance nwrapper))
1136 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
1137 ;;; the next access to the instance (as defined in 88-002R) to trap
1138 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
1139 (defmethod make-instances-obsolete ((class std-class))
1140 (let* ((owrapper (class-wrapper class))
1141 (nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1143 (setf (wrapper-instance-slots-layout nwrapper)
1144 (wrapper-instance-slots-layout owrapper))
1145 (setf (wrapper-class-slots nwrapper)
1146 (wrapper-class-slots owrapper))
1147 (sb-sys:without-interrupts
1148 (update-lisp-class-layout class nwrapper)
1149 (setf (slot-value class 'wrapper) nwrapper)
1150 (invalidate-wrapper owrapper :obsolete nwrapper)
1153 (defmethod make-instances-obsolete ((class symbol))
1154 (make-instances-obsolete (find-class class)))
1156 ;;; OBSOLETE-INSTANCE-TRAP is the internal trap that is called when we
1157 ;;; see an obsolete instance. The times when it is called are:
1158 ;;; - when the instance is involved in method lookup
1159 ;;; - when attempting to access a slot of an instance
1161 ;;; It is not called by class-of, wrapper-of, or any of the low-level
1162 ;;; instance access macros.
1164 ;;; Of course these times when it is called are an internal
1165 ;;; implementation detail of PCL and are not part of the documented
1166 ;;; description of when the obsolete instance update happens. The
1167 ;;; documented description is as it appears in 88-002R.
1169 ;;; This has to return the new wrapper, so it counts on all the
1170 ;;; methods on obsolete-instance-trap-internal to return the new
1171 ;;; wrapper. It also does a little internal error checking to make
1172 ;;; sure that the traps are only happening when they should, and that
1173 ;;; the trap methods are computing appropriate new wrappers.
1175 ;;; OBSOLETE-INSTANCE-TRAP might be called on structure instances
1176 ;;; after a structure is redefined. In most cases,
1177 ;;; OBSOLETE-INSTANCE-TRAP will not be able to fix the old instance,
1178 ;;; so it must signal an error. The hard part of this is that the
1179 ;;; error system and debugger might cause OBSOLETE-INSTANCE-TRAP to be
1180 ;;; called again, so in that case, we have to return some reasonable
1181 ;;; wrapper, instead.
1183 (defvar *in-obsolete-instance-trap* nil)
1184 (defvar *the-wrapper-of-structure-object*
1185 (class-wrapper (find-class 'structure-object)))
1187 (define-condition obsolete-structure (error)
1188 ((datum :reader obsolete-structure-datum :initarg :datum))
1190 (lambda (condition stream)
1191 ;; Don't try to print the structure, since it probably won't work.
1193 "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
1194 (type-of (obsolete-structure-datum condition))))))
1196 (defun obsolete-instance-trap (owrapper nwrapper instance)
1197 (if (not (pcl-instance-p instance))
1198 (if *in-obsolete-instance-trap*
1199 *the-wrapper-of-structure-object*
1200 (let ((*in-obsolete-instance-trap* t))
1201 (error 'obsolete-structure :datum instance)))
1202 (let* ((class (wrapper-class* nwrapper))
1203 (copy (allocate-instance class)) ;??? allocate-instance ???
1204 (olayout (wrapper-instance-slots-layout owrapper))
1205 (nlayout (wrapper-instance-slots-layout nwrapper))
1206 (oslots (get-slots instance))
1207 (nslots (get-slots copy))
1208 (oclass-slots (wrapper-class-slots owrapper))
1212 ;; local --> local transfer
1213 ;; local --> shared discard
1214 ;; local --> -- discard
1215 ;; shared --> local transfer
1216 ;; shared --> shared discard
1217 ;; shared --> -- discard
1221 ;; Go through all the old local slots.
1223 (dolist (name olayout)
1224 (let ((npos (posq name nlayout)))
1226 (setf (clos-slots-ref nslots npos)
1227 (clos-slots-ref oslots opos))
1229 (push name discarded)
1230 (unless (eq (clos-slots-ref oslots opos) +slot-unbound+)
1231 (setf (getf plist name) (clos-slots-ref oslots opos))))))
1234 ;; Go through all the old shared slots.
1235 (dolist (oclass-slot-and-val oclass-slots)
1236 (let ((name (car oclass-slot-and-val))
1237 (val (cdr oclass-slot-and-val)))
1238 (let ((npos (posq name nlayout)))
1240 (setf (clos-slots-ref nslots npos) (cdr oclass-slot-and-val))
1241 (progn (push name discarded)
1242 (unless (eq val +slot-unbound+)
1243 (setf (getf plist name) val)))))))
1245 ;; Go through all the new local slots to compute the added slots.
1246 (dolist (nlocal nlayout)
1247 (unless (or (memq nlocal olayout)
1248 (assq nlocal oclass-slots))
1249 (push nlocal added)))
1251 (swap-wrappers-and-slots instance copy)
1253 (update-instance-for-redefined-class instance
1259 (defun change-class-internal (instance new-class initargs)
1260 (let* ((old-class (class-of instance))
1261 (copy (allocate-instance new-class))
1262 (new-wrapper (get-wrapper copy))
1263 (old-wrapper (class-wrapper old-class))
1264 (old-layout (wrapper-instance-slots-layout old-wrapper))
1265 (new-layout (wrapper-instance-slots-layout new-wrapper))
1266 (old-slots (get-slots instance))
1267 (new-slots (get-slots copy))
1268 (old-class-slots (wrapper-class-slots old-wrapper)))
1270 ;; "The values of local slots specified by both the class CTO and
1271 ;; CFROM are retained. If such a local slot was unbound, it
1272 ;; remains unbound."
1273 (let ((new-position 0))
1274 (dolist (new-slot new-layout)
1275 (let ((old-position (posq new-slot old-layout)))
1277 (setf (clos-slots-ref new-slots new-position)
1278 (clos-slots-ref old-slots old-position))))
1279 (incf new-position)))
1281 ;; "The values of slots specified as shared in the class CFROM and
1282 ;; as local in the class CTO are retained."
1283 (dolist (slot-and-val old-class-slots)
1284 (let ((position (posq (car slot-and-val) new-layout)))
1286 (setf (clos-slots-ref new-slots position) (cdr slot-and-val)))))
1288 ;; Make the copy point to the old instance's storage, and make the
1289 ;; old instance point to the new storage.
1290 (swap-wrappers-and-slots instance copy)
1292 (apply #'update-instance-for-different-class copy instance initargs)
1295 (defmethod change-class ((instance standard-object)
1296 (new-class standard-class)
1298 (change-class-internal instance new-class initargs))
1300 (defmethod change-class ((instance funcallable-standard-object)
1301 (new-class funcallable-standard-class)
1303 (change-class-internal instance new-class initargs))
1305 (defmethod change-class ((instance standard-object)
1306 (new-class funcallable-standard-class)
1308 (declare (ignore initargs))
1309 (error "You can't change the class of ~S to ~S~@
1310 because it isn't already an instance with metaclass ~S."
1311 instance new-class 'standard-class))
1313 (defmethod change-class ((instance funcallable-standard-object)
1314 (new-class standard-class)
1316 (declare (ignore initargs))
1317 (error "You can't change the class of ~S to ~S~@
1318 because it isn't already an instance with metaclass ~S."
1319 instance new-class 'funcallable-standard-class))
1321 (defmethod change-class ((instance t) (new-class-name symbol) &rest initargs)
1322 (apply #'change-class instance (find-class new-class-name) initargs))
1324 ;;;; The metaclass BUILT-IN-CLASS
1326 ;;;; This metaclass is something of a weird creature. By this point, all
1327 ;;;; instances of it which will exist have been created, and no instance
1328 ;;;; is ever created by calling MAKE-INSTANCE.
1330 ;;;; But, there are other parts of the protocol we must follow and those
1331 ;;;; definitions appear here.
1333 (defmethod shared-initialize :before
1334 ((class built-in-class) slot-names &rest initargs)
1335 (declare (ignore slot-names initargs))
1336 (error "attempt to initialize or reinitialize a built in class"))
1338 (defmethod class-direct-slots ((class built-in-class)) ())
1339 (defmethod class-slots ((class built-in-class)) ())
1340 (defmethod class-direct-default-initargs ((class built-in-class)) ())
1341 (defmethod class-default-initargs ((class built-in-class)) ())
1343 (defmethod validate-superclass ((c class) (s built-in-class))
1344 (or (eq s *the-class-t*)
1345 (eq s *the-class-stream*)))
1347 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
1348 (defmethod class-direct-slots ((class forward-referenced-class)) ())
1349 (defmethod class-direct-default-initargs ((class forward-referenced-class)) ())
1350 (macrolet ((def (method)
1351 `(defmethod ,method ((class forward-referenced-class))
1352 (error "~@<~I~S was called on a forward referenced class:~2I~_~S~:>"
1354 (def class-default-initargs)
1355 (def class-precedence-list)
1358 (defmethod validate-superclass ((c slot-class)
1359 (f forward-referenced-class))
1362 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
1363 (pushnew dependent (plist-value metaobject 'dependents)))
1365 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
1366 (setf (plist-value metaobject 'dependents)
1367 (delete dependent (plist-value metaobject 'dependents))))
1369 (defmethod map-dependents ((metaobject dependent-update-mixin) function)
1370 (dolist (dependent (plist-value metaobject 'dependents))
1371 (funcall function dependent)))