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)
327 (setf (gdefinition 'load-defclass) #'real-load-defclass)
329 (defun ensure-class (name &rest all)
330 (apply #'ensure-class-using-class name (find-class name nil) all))
332 (defmethod ensure-class-using-class (name (class null) &rest args &key)
333 (multiple-value-bind (meta initargs)
334 (ensure-class-values class args)
335 (set-class-type-translation (class-prototype meta) name)
336 (setf class (apply #'make-instance meta :name name initargs)
337 (find-class name) class)
338 (set-class-type-translation class name)
341 (defmethod ensure-class-using-class (name (class pcl-class) &rest args &key)
342 (multiple-value-bind (meta initargs)
343 (ensure-class-values class args)
344 (unless (eq (class-of class) meta) (change-class class meta))
345 (apply #'reinitialize-instance class initargs)
346 (setf (find-class name) class)
347 (set-class-type-translation class name)
350 (defmethod class-predicate-name ((class t))
355 ((not (legal-class-name-p s))
356 (error "~S is not a class or a legal class name." s))
358 (or (find-class s nil)
360 (make-instance 'forward-referenced-class
363 (defun ensure-class-values (class args)
364 (let* ((initargs (copy-list args))
365 (unsupplied (list 1))
366 (supplied-meta (getf initargs :metaclass unsupplied))
367 (supplied-supers (getf initargs :direct-superclasses unsupplied))
368 (supplied-slots (getf initargs :direct-slots unsupplied))
370 (cond ((neq supplied-meta unsupplied)
371 (find-class supplied-meta))
373 (forward-referenced-class-p class))
374 *the-class-standard-class*)
377 ;; KLUDGE: It seemed to me initially that there ought to be a way
378 ;; of collecting all the erroneous problems in one go, rather than
379 ;; this way of solving the problem of signalling the errors that
380 ;; we are required to, which stops at the first bogus input.
381 ;; However, after playing around a little, I couldn't find that
382 ;; way, so I've left it as is, but if someone does come up with a
383 ;; better way... -- CSR, 2002-09-08
384 (do ((direct-slots (getf initargs :direct-slots) (cdr direct-slots)))
385 ((endp direct-slots) nil)
386 (destructuring-bind (slot &rest more) direct-slots
387 (let ((slot-name (getf slot :name)))
388 (when (some (lambda (s) (eq slot-name (getf s :name))) more)
389 ;; FIXME: It's quite possible that we ought to define an
390 ;; SB-INT:PROGRAM-ERROR function to signal these and other
391 ;; errors throughout the codebase that are required to be
392 ;; of type PROGRAM-ERROR.
393 (error 'simple-program-error
394 :format-control "~@<There is more than one direct slot ~
396 :format-arguments (list slot-name)))
397 (do ((stuff slot (cddr stuff)))
399 (destructuring-bind (option value &rest more) stuff
401 ((and (member option '(:allocation :type
402 :initform :documentation))
404 (getf more option unsupplied))))
405 (error 'simple-program-error
406 :format-control "~@<Duplicate slot option ~S for ~
408 :format-arguments (list option slot-name)))
409 ((and (eq option :readers)
410 (notevery #'symbolp value))
411 (error 'simple-program-error
412 :format-control "~@<Slot reader names for slot ~
413 named ~S must be symbols.~:>"
414 :format-arguments (list slot-name)))
415 ((and (eq option :initargs)
416 (notevery #'symbolp value))
417 (error 'simple-program-error
418 :format-control "~@<Slot initarg names for slot ~
419 named ~S must be symbols.~:>"
420 :format-arguments (list slot-name)))))))))
421 (loop for (initarg . more) on (getf initargs :direct-default-initargs)
422 for name = (car initarg)
423 when (some (lambda (a) (eq (car a) name)) more)
424 do (error 'simple-program-error
425 :format-control "~@<Duplicate initialization argument ~
426 name ~S in :DEFAULT-INITARGS.~:>"
427 :format-arguments (list name class)))
429 (default-initargs 0))
430 (do ((args initargs (cddr args)))
434 (when (> (incf metaclass) 1)
435 (error 'simple-program-error
436 :format-control "~@<More than one :METACLASS ~
437 option specified.~:>")))
438 (:direct-default-initargs
439 (when (> (incf default-initargs) 1)
440 (error 'simple-program-error
441 :format-control "~@<More than one :DEFAULT-INITARGS ~
442 option specified.~:>"))))))
443 (remf initargs :metaclass)
444 (loop (unless (remf initargs :direct-superclasses) (return)))
445 (loop (unless (remf initargs :direct-slots) (return)))
449 (when (neq supplied-supers unsupplied)
450 (list :direct-superclasses (mapcar #'fix-super supplied-supers)))
451 (when (neq supplied-slots unsupplied)
452 (list :direct-slots supplied-slots))
455 (defmethod shared-initialize :after
458 &key (direct-superclasses nil direct-superclasses-p)
459 (direct-slots nil direct-slots-p)
460 (direct-default-initargs nil direct-default-initargs-p)
461 (predicate-name nil predicate-name-p))
462 (declare (ignore slot-names))
463 (cond (direct-superclasses-p
464 (setq direct-superclasses
465 (or direct-superclasses
466 (list (if (funcallable-standard-class-p class)
467 *the-class-funcallable-standard-object*
468 *the-class-standard-object*))))
469 (dolist (superclass direct-superclasses)
470 (unless (validate-superclass class superclass)
471 (error "The class ~S was specified as a~%
472 super-class of the class ~S;~%~
473 but the meta-classes ~S and~%~S are incompatible.~@
474 Define a method for ~S to avoid this error."
475 superclass class (class-of superclass) (class-of class)
476 'validate-superclass)))
477 (setf (slot-value class 'direct-superclasses) direct-superclasses))
479 (setq direct-superclasses (slot-value class 'direct-superclasses))))
482 (setf (slot-value class 'direct-slots)
483 (mapcar (lambda (pl) (make-direct-slotd class pl))
485 (slot-value class 'direct-slots)))
486 (if direct-default-initargs-p
487 (setf (plist-value class 'direct-default-initargs)
488 direct-default-initargs)
489 (setq direct-default-initargs
490 (plist-value class 'direct-default-initargs)))
491 (setf (plist-value class 'class-slot-cells)
493 (dolist (dslotd direct-slots)
494 (when (eq :class (slot-definition-allocation dslotd))
495 (let ((initfunction (slot-definition-initfunction dslotd)))
496 (push (cons (slot-definition-name dslotd)
498 (funcall initfunction)
502 (setq predicate-name (if predicate-name-p
503 (setf (slot-value class 'predicate-name)
504 (car predicate-name))
505 (or (slot-value class 'predicate-name)
506 (setf (slot-value class 'predicate-name)
507 (make-class-predicate-name (class-name
509 (add-direct-subclasses class direct-superclasses)
510 (update-class class nil)
511 (make-class-predicate class predicate-name)
512 (add-slot-accessors class direct-slots))
514 (defmethod shared-initialize :before ((class class) slot-names &key name)
515 (declare (ignore slot-names name))
516 ;; FIXME: Could this just be CLASS instead of `(CLASS ,CLASS)? If not,
517 ;; why not? (See also similar expression in !BOOTSTRAP-INITIALIZE-CLASS.)
518 (setf (slot-value class 'type) `(class ,class))
519 (setf (slot-value class 'class-eq-specializer)
520 (make-instance 'class-eq-specializer :class class)))
522 (defmethod reinitialize-instance :before ((class slot-class) &key)
523 (remove-direct-subclasses class (class-direct-superclasses class))
524 (remove-slot-accessors class (class-direct-slots class)))
526 (defmethod reinitialize-instance :after ((class slot-class)
529 (map-dependents class
531 (apply #'update-dependent class dependent initargs))))
533 (defmethod shared-initialize :after ((class condition-class) slot-names
534 &key direct-superclasses)
535 (declare (ignore slot-names))
536 (let ((classoid (find-classoid (class-name class))))
537 (with-slots (wrapper class-precedence-list prototype predicate-name
538 (direct-supers direct-superclasses))
540 (setf (classoid-pcl-class classoid) class)
541 (setq direct-supers direct-superclasses)
542 (setq wrapper (classoid-layout classoid))
543 (setq class-precedence-list (compute-class-precedence-list class))
544 (setq prototype (make-condition (class-name class)))
545 (add-direct-subclasses class direct-superclasses)
546 (setq predicate-name (make-class-predicate-name (class-name class)))
547 (make-class-predicate class predicate-name))))
549 (defmethod shared-initialize :after
550 ((slotd structure-slot-definition) slot-names &key
551 (allocation :instance) allocation-class)
552 (declare (ignore slot-names allocation-class))
553 (unless (eq allocation :instance)
554 (error "Structure slots must have :INSTANCE allocation.")))
556 (defun make-structure-class-defstruct-form (name direct-slots include)
557 (let* ((conc-name (intern (format nil "~S structure class " name)))
558 (constructor (intern (format nil "~Aconstructor" conc-name)))
559 (defstruct `(defstruct (,name
561 `((:include ,(class-name include))))
563 (:conc-name ,conc-name)
564 (:constructor ,constructor ())
566 ,@(mapcar (lambda (slot)
567 `(,(slot-definition-name slot)
570 (reader-names (mapcar (lambda (slotd)
571 (list 'slot-accessor name
572 (slot-definition-name slotd)
575 (writer-names (mapcar (lambda (slotd)
576 (list 'slot-accessor name
577 (slot-definition-name slotd)
581 (mapcar (lambda (slotd reader-name)
583 (slot-definition-defstruct-accessor-symbol
585 `(defun ,reader-name (obj)
586 (declare (type ,name obj))
588 direct-slots reader-names))
590 (mapcar (lambda (slotd writer-name)
592 (slot-definition-defstruct-accessor-symbol
594 `(defun ,writer-name (nv obj)
595 (declare (type ,name obj))
596 (setf (,accessor obj) nv))))
597 direct-slots writer-names))
601 ,@readers-init ,@writers-init
603 (values defstruct-form constructor reader-names writer-names)))
605 (defmethod shared-initialize :after
606 ((class structure-class)
608 &key (direct-superclasses nil direct-superclasses-p)
609 (direct-slots nil direct-slots-p)
610 direct-default-initargs
611 (predicate-name nil predicate-name-p))
612 (declare (ignore slot-names direct-default-initargs))
613 (if direct-superclasses-p
614 (setf (slot-value class 'direct-superclasses)
615 (or direct-superclasses
616 (setq direct-superclasses
617 (and (not (eq (class-name class) 'structure-object))
618 (list *the-class-structure-object*)))))
619 (setq direct-superclasses (slot-value class 'direct-superclasses)))
620 (let* ((name (class-name class))
621 (from-defclass-p (slot-value class 'from-defclass-p))
622 (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
624 (setf (slot-value class 'direct-slots)
628 (let* ((slot-name (getf pl :name))
631 "~S structure class ~A"
633 (accessor (intern acc-name)))
634 (setq pl (list* :defstruct-accessor-symbol
636 (make-direct-slotd class pl))
638 (setq direct-slots (slot-value class 'direct-slots)))
640 (let ((include (car (slot-value class 'direct-superclasses))))
641 (multiple-value-bind (defstruct-form constructor reader-names writer-names)
642 (make-structure-class-defstruct-form name direct-slots include)
643 (unless (structure-type-p name) (eval defstruct-form))
644 (mapc (lambda (dslotd reader-name writer-name)
645 (let* ((reader (gdefinition reader-name))
646 (writer (when (gboundp writer-name)
647 (gdefinition writer-name))))
648 (setf (slot-value dslotd 'internal-reader-function)
650 (setf (slot-value dslotd 'internal-writer-function)
652 direct-slots reader-names writer-names)
653 (setf (slot-value class 'defstruct-form) defstruct-form)
654 (setf (slot-value class 'defstruct-constructor) constructor))))
655 (add-direct-subclasses class direct-superclasses)
656 (setf (slot-value class 'class-precedence-list)
657 (compute-class-precedence-list class))
658 (setf (slot-value class 'slots) (compute-slots class))
659 (let ((lclass (find-classoid (class-name class))))
660 (setf (classoid-pcl-class lclass) class)
661 (setf (slot-value class 'wrapper) (classoid-layout lclass)))
662 (update-pv-table-cache-info class)
663 (setq predicate-name (if predicate-name-p
664 (setf (slot-value class 'predicate-name)
665 (car predicate-name))
666 (or (slot-value class 'predicate-name)
667 (setf (slot-value class 'predicate-name)
668 (make-class-predicate-name
669 (class-name class))))))
670 (make-class-predicate class predicate-name)
671 (add-slot-accessors class direct-slots)))
673 (defmethod direct-slot-definition-class ((class structure-class) initargs)
674 (declare (ignore initargs))
675 (find-class 'structure-direct-slot-definition))
677 (defmethod finalize-inheritance ((class structure-class))
678 nil) ; always finalized
680 (defun add-slot-accessors (class dslotds)
681 (fix-slot-accessors class dslotds 'add))
683 (defun remove-slot-accessors (class dslotds)
684 (fix-slot-accessors class dslotds 'remove))
686 (defun fix-slot-accessors (class dslotds add/remove)
687 (flet ((fix (gfspec name r/w)
688 (let ((gf (ensure-generic-function gfspec)))
690 (r (if (eq add/remove 'add)
691 (add-reader-method class gf name)
692 (remove-reader-method class gf)))
693 (w (if (eq add/remove 'add)
694 (add-writer-method class gf name)
695 (remove-writer-method class gf)))))))
696 (dolist (dslotd dslotds)
697 (let ((slot-name (slot-definition-name dslotd)))
698 (dolist (r (slot-definition-readers dslotd)) (fix r slot-name 'r))
699 (dolist (w (slot-definition-writers dslotd)) (fix w slot-name 'w))))))
701 (defun add-direct-subclasses (class supers)
702 (dolist (super supers)
703 (unless (memq class (class-direct-subclasses class))
704 (add-direct-subclass super class))))
706 (defun remove-direct-subclasses (class supers)
707 (let ((old (class-direct-superclasses class)))
708 (dolist (o (set-difference old supers))
709 (remove-direct-subclass o class))))
711 (defmethod finalize-inheritance ((class std-class))
712 (update-class class t))
714 (defmethod finalize-inheritance ((class forward-referenced-class))
715 ;; FIXME: should we not be thinking a bit about what kinds of error
716 ;; we're throwing? Maybe we need a clos-error type to mix in? Or
717 ;; possibly a forward-referenced-class-error, though that's
718 ;; difficult given e.g. class precedence list calculations...
720 "~@<FINALIZE-INHERITANCE was called on a forward referenced class:~
725 (defun class-has-a-forward-referenced-superclass-p (class)
726 (or (forward-referenced-class-p class)
727 (some #'class-has-a-forward-referenced-superclass-p
728 (class-direct-superclasses class))))
730 ;;; This is called by :after shared-initialize whenever a class is initialized
731 ;;; or reinitialized. The class may or may not be finalized.
732 (defun update-class (class finalizep)
733 ;; Comment from Gerd Moellmann:
735 ;; Note that we can't simply delay the finalization when CLASS has
736 ;; no forward referenced superclasses because that causes bootstrap
738 (when (and (not finalizep)
739 (not (class-finalized-p class))
740 (not (class-has-a-forward-referenced-superclass-p class)))
741 (finalize-inheritance class)
742 (return-from update-class))
743 (when (or finalizep (class-finalized-p class)
744 (not (class-has-a-forward-referenced-superclass-p class)))
745 (update-cpl class (compute-class-precedence-list class))
746 ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
747 ;; class. The hoops above are to ensure that FINALIZE-INHERITANCE
748 ;; is called at finalization, so that MOP programmers can hook
749 ;; into the system as described in "Class Finalization Protocol"
750 ;; (section 5.5.2 of AMOP).
751 (update-slots class (compute-slots class))
752 (update-gfs-of-class class)
753 (update-inits class (compute-default-initargs class))
754 (update-ctors 'finalize-inheritance :class class))
756 (dolist (sub (class-direct-subclasses class)) (update-class sub nil))))
758 (defun update-cpl (class cpl)
759 (if (class-finalized-p class)
760 (unless (equal (class-precedence-list class) cpl)
761 ;; comment from the old CMU CL sources:
762 ;; Need to have the cpl setup before update-lisp-class-layout
763 ;; is called on CMU CL.
764 (setf (slot-value class 'class-precedence-list) cpl)
765 (force-cache-flushes class))
766 (setf (slot-value class 'class-precedence-list) cpl))
767 (update-class-can-precede-p cpl))
769 (defun update-class-can-precede-p (cpl)
771 (let ((first (car cpl)))
772 (dolist (c (cdr cpl))
773 (pushnew c (slot-value first 'can-precede-list))))
774 (update-class-can-precede-p (cdr cpl))))
776 (defun class-can-precede-p (class1 class2)
777 (member class2 (class-can-precede-list class1)))
779 (defun update-slots (class eslotds)
780 (let ((instance-slots ())
782 (dolist (eslotd eslotds)
783 (let ((alloc (slot-definition-allocation eslotd)))
785 (:instance (push eslotd instance-slots))
786 (:class (push eslotd class-slots)))))
788 ;; If there is a change in the shape of the instances then the
789 ;; old class is now obsolete.
790 (let* ((nlayout (mapcar #'slot-definition-name
791 (sort instance-slots #'<
792 :key #'slot-definition-location)))
793 (nslots (length nlayout))
794 (nwrapper-class-slots (compute-class-slots class-slots))
795 (owrapper (class-wrapper class))
796 (olayout (and owrapper (wrapper-instance-slots-layout owrapper)))
797 (owrapper-class-slots (and owrapper (wrapper-class-slots owrapper)))
799 (cond ((null owrapper)
800 (make-wrapper nslots class))
801 ((and (equal nlayout olayout)
803 (loop for o in owrapper-class-slots
804 for n in nwrapper-class-slots
805 do (unless (eq (car o) (car n)) (return t)))))
808 ;; This will initialize the new wrapper to have the
809 ;; same state as the old wrapper. We will then have
810 ;; to change that. This may seem like wasted work
811 ;; (and it is), but the spec requires that we call
812 ;; MAKE-INSTANCES-OBSOLETE.
813 (make-instances-obsolete class)
814 (class-wrapper class)))))
816 (with-slots (wrapper slots) class
817 (update-lisp-class-layout class nwrapper)
819 (wrapper-instance-slots-layout nwrapper) nlayout
820 (wrapper-class-slots nwrapper) nwrapper-class-slots
821 (wrapper-no-of-instance-slots nwrapper) nslots
824 (unless (eq owrapper nwrapper)
825 (update-pv-table-cache-info class)))))
827 (defun compute-class-slots (eslotds)
829 (dolist (eslotd eslotds)
830 (push (assoc (slot-definition-name eslotd)
831 (class-slot-cells (slot-definition-class eslotd)))
835 (defun update-gfs-of-class (class)
836 (when (and (class-finalized-p class)
837 (let ((cpl (class-precedence-list class)))
838 (or (member *the-class-slot-class* cpl)
839 (member *the-class-standard-effective-slot-definition*
841 (let ((gf-table (make-hash-table :test 'eq)))
842 (labels ((collect-gfs (class)
843 (dolist (gf (specializer-direct-generic-functions class))
844 (setf (gethash gf gf-table) t))
845 (mapc #'collect-gfs (class-direct-superclasses class))))
847 (maphash (lambda (gf ignore)
848 (declare (ignore ignore))
849 (update-gf-dfun class gf))
852 (defun update-inits (class inits)
853 (setf (plist-value class 'default-initargs) inits))
855 (defmethod compute-default-initargs ((class slot-class))
856 (let ((cpl (class-precedence-list class))
857 (direct (class-direct-default-initargs class)))
858 (labels ((walk (tail)
861 (let ((c (pop tail)))
862 (append (if (eq c class)
864 (class-direct-default-initargs c))
866 (let ((initargs (walk cpl)))
867 (delete-duplicates initargs :test #'eq :key #'car :from-end t)))))
869 ;;;; protocols for constructing direct and effective slot definitions
871 (defmethod direct-slot-definition-class ((class std-class) initargs)
872 (declare (ignore initargs))
873 (find-class 'standard-direct-slot-definition))
875 (defun make-direct-slotd (class initargs)
876 (let ((initargs (list* :class class initargs)))
877 (apply #'make-instance
878 (direct-slot-definition-class class initargs)
881 (defmethod compute-slots ((class std-class))
882 ;; As specified, we must call COMPUTE-EFFECTIVE-SLOT-DEFINITION once
883 ;; for each different slot name we find in our superclasses. Each
884 ;; call receives the class and a list of the dslotds with that name.
885 ;; The list is in most-specific-first order.
886 (let ((name-dslotds-alist ()))
887 (dolist (c (class-precedence-list class))
888 (dolist (slot (class-direct-slots c))
889 (let* ((name (slot-definition-name slot))
890 (entry (assq name name-dslotds-alist)))
892 (push slot (cdr entry))
893 (push (list name slot) name-dslotds-alist)))))
894 (mapcar (lambda (direct)
895 (compute-effective-slot-definition class
896 (nreverse (cdr direct))))
897 name-dslotds-alist)))
899 (defmethod compute-slots ((class standard-class))
902 (defmethod compute-slots :around ((class standard-class))
903 (let ((eslotds (call-next-method))
905 (dolist (eslotd eslotds eslotds)
906 (setf (slot-definition-location eslotd)
907 (ecase (slot-definition-allocation eslotd)
911 (let* ((name (slot-definition-name eslotd))
912 (from-class (slot-definition-allocation-class eslotd))
913 (cell (assq name (class-slot-cells from-class))))
916 (initialize-internal-slot-functions eslotd))))
918 (defmethod compute-slots ((class funcallable-standard-class))
921 (defmethod compute-slots :around ((class funcallable-standard-class))
922 (labels ((instance-slot-names (slotds)
924 (dolist (slotd slotds (nreverse collect))
925 (when (eq (slot-definition-allocation slotd) :instance)
926 (push (slot-definition-name slotd) collect)))))
927 ;; This sorts slots so that slots of classes later in the CPL
928 ;; come before slots of other classes. This is crucial for
929 ;; funcallable instances because it ensures that the slots of
930 ;; FUNCALLABLE-STANDARD-OBJECT, which includes the slots of
931 ;; KERNEL:FUNCALLABLE-INSTANCE, come first, which in turn
932 ;; makes it possible to treat FUNCALLABLE-STANDARD-OBJECT as
933 ;; a funcallable instance.
934 (compute-layout (eslotds)
936 (names (instance-slot-names eslotds)))
938 (reverse (class-precedence-list class))
939 (nreverse (nconc names first)))
940 (dolist (ss (class-slots class))
941 (let ((name (slot-definition-name ss)))
942 (when (member name names)
944 (setq names (delete name names)))))))))
945 (let ((all-slotds (call-next-method))
948 (dolist (slotd all-slotds)
949 (ecase (slot-definition-allocation slotd)
950 (:instance (push slotd instance-slots))
951 (:class (push slotd class-slots))))
952 (let ((layout (compute-layout instance-slots)))
953 (dolist (slotd instance-slots)
954 (setf (slot-definition-location slotd)
955 (position (slot-definition-name slotd) layout))
956 (initialize-internal-slot-functions slotd)))
957 (dolist (slotd class-slots)
958 (let ((name (slot-definition-name slotd))
959 (from-class (slot-definition-allocation-class slotd)))
960 (setf (slot-definition-location slotd)
961 (assoc name (class-slot-cells from-class)))
962 (aver (consp (slot-definition-location slotd)))
963 (initialize-internal-slot-functions slotd)))
966 (defmethod compute-slots ((class structure-class))
967 (mapcan (lambda (superclass)
968 (mapcar (lambda (dslotd)
969 (compute-effective-slot-definition class
971 (class-direct-slots superclass)))
972 (reverse (slot-value class 'class-precedence-list))))
974 (defmethod compute-slots :around ((class structure-class))
975 (let ((eslotds (call-next-method)))
976 (mapc #'initialize-internal-slot-functions eslotds)
979 (defmethod compute-effective-slot-definition ((class slot-class) dslotds)
980 (let* ((initargs (compute-effective-slot-definition-initargs class dslotds))
981 (class (effective-slot-definition-class class initargs)))
982 (apply #'make-instance class initargs)))
984 (defmethod effective-slot-definition-class ((class std-class) initargs)
985 (declare (ignore initargs))
986 (find-class 'standard-effective-slot-definition))
988 (defmethod effective-slot-definition-class ((class structure-class) initargs)
989 (declare (ignore initargs))
990 (find-class 'structure-effective-slot-definition))
992 (defmethod compute-effective-slot-definition-initargs
993 ((class slot-class) direct-slotds)
999 (allocation-class nil)
1005 (dolist (slotd direct-slotds)
1008 (setq name (slot-definition-name slotd)
1011 (when (slot-definition-initfunction slotd)
1012 (setq initform (slot-definition-initform slotd)
1013 initfunction (slot-definition-initfunction slotd)
1016 (setq allocation (slot-definition-allocation slotd)
1017 allocation-class (slot-definition-class slotd)
1019 (setq initargs (append (slot-definition-initargs slotd) initargs))
1020 (let ((slotd-type (slot-definition-type slotd)))
1021 (setq type (cond ((eq type t) slotd-type)
1022 ((*subtypep type slotd-type) type)
1023 (t `(and ,type ,slotd-type)))))))
1026 :initfunction initfunction
1028 :allocation allocation
1029 :allocation-class allocation-class
1033 (defmethod compute-effective-slot-definition-initargs :around
1034 ((class structure-class) direct-slotds)
1035 (let ((slotd (car direct-slotds)))
1036 (list* :defstruct-accessor-symbol
1037 (slot-definition-defstruct-accessor-symbol slotd)
1038 :internal-reader-function
1039 (slot-definition-internal-reader-function slotd)
1040 :internal-writer-function
1041 (slot-definition-internal-writer-function slotd)
1042 (call-next-method))))
1044 ;;; NOTE: For bootstrapping considerations, these can't use MAKE-INSTANCE
1045 ;;; to make the method object. They have to use make-a-method which
1046 ;;; is a specially bootstrapped mechanism for making standard methods.
1047 (defmethod reader-method-class ((class slot-class) direct-slot &rest initargs)
1048 (declare (ignore direct-slot initargs))
1049 (find-class 'standard-reader-method))
1051 (defmethod add-reader-method ((class slot-class) generic-function slot-name)
1052 (add-method generic-function
1053 (make-a-method 'standard-reader-method
1055 (list (or (class-name class) 'object))
1057 (make-reader-method-function class slot-name)
1058 "automatically generated reader method"
1061 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
1062 (declare (ignore direct-slot initargs))
1063 (find-class 'standard-writer-method))
1065 (defmethod add-writer-method ((class slot-class) generic-function slot-name)
1066 (add-method generic-function
1067 (make-a-method 'standard-writer-method
1069 (list 'new-value (or (class-name class) 'object))
1070 (list *the-class-t* class)
1071 (make-writer-method-function class slot-name)
1072 "automatically generated writer method"
1075 (defmethod add-boundp-method ((class slot-class) generic-function slot-name)
1076 (add-method generic-function
1077 (make-a-method 'standard-boundp-method
1079 (list (or (class-name class) 'object))
1081 (make-boundp-method-function class slot-name)
1082 "automatically generated boundp method"
1085 (defmethod remove-reader-method ((class slot-class) generic-function)
1086 (let ((method (get-method generic-function () (list class) nil)))
1087 (when method (remove-method generic-function method))))
1089 (defmethod remove-writer-method ((class slot-class) generic-function)
1091 (get-method generic-function () (list *the-class-t* class) nil)))
1092 (when method (remove-method generic-function method))))
1094 (defmethod remove-boundp-method ((class slot-class) generic-function)
1095 (let ((method (get-method generic-function () (list class) nil)))
1096 (when method (remove-method generic-function method))))
1098 ;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITE-METHOD function are NOT
1099 ;;; part of the standard protocol. They are however useful, PCL makes
1100 ;;; use of them internally and documents them for PCL users.
1102 ;;; *** This needs work to make type testing by the writer functions which
1103 ;;; *** do type testing faster. The idea would be to have one constructor
1104 ;;; *** for each possible type test.
1106 ;;; *** There is a subtle bug here which is going to have to be fixed.
1107 ;;; *** Namely, the simplistic use of the template has to be fixed. We
1108 ;;; *** have to give the OPTIMIZE-SLOT-VALUE method the user might have
1109 ;;; *** defined for this metaclass a chance to run.
1111 (defmethod make-reader-method-function ((class slot-class) slot-name)
1112 (make-std-reader-method-function (class-name class) slot-name))
1114 (defmethod make-writer-method-function ((class slot-class) slot-name)
1115 (make-std-writer-method-function (class-name class) slot-name))
1117 (defmethod make-boundp-method-function ((class slot-class) slot-name)
1118 (make-std-boundp-method-function (class-name class) slot-name))
1120 (defmethod compatible-meta-class-change-p (class proto-new-class)
1121 (eq (class-of class) (class-of proto-new-class)))
1123 (defmethod validate-superclass ((class class) (new-super class))
1124 (or (eq new-super *the-class-t*)
1125 (eq (class-of class) (class-of new-super))))
1127 (defmethod validate-superclass ((class standard-class) (new-super std-class))
1128 (let ((new-super-meta-class (class-of new-super)))
1129 (or (eq new-super-meta-class *the-class-std-class*)
1130 (eq (class-of class) new-super-meta-class))))
1132 ;;; What this does depends on which of the four possible values of
1133 ;;; LAYOUT-INVALID the PCL wrapper has; the simplest case is when it
1134 ;;; is (:FLUSH <wrapper>) or (:OBSOLETE <wrapper>), when there is
1135 ;;; nothing to do, as the new wrapper has already been created. If
1136 ;;; LAYOUT-INVALID returns NIL, then we invalidate it (setting it to
1137 ;;; (:FLUSH <wrapper>); UPDATE-SLOTS later gets to choose whether or
1138 ;;; not to "upgrade" this to (:OBSOLETE <wrapper>).
1140 ;;; This leaves the case where LAYOUT-INVALID returns T, which happens
1141 ;;; when REGISTER-LAYOUT has invalidated a superclass of CLASS (which
1142 ;;; invalidated all the subclasses in SB-KERNEL land). Again, here we
1143 ;;; must flush the caches and allow UPDATE-SLOTS to decide whether to
1144 ;;; obsolete the wrapper.
1146 ;;; FIXME: either here or in INVALID-WRAPPER-P looks like a good place
1147 ;;; for (AVER (NOT (EQ (LAYOUT-INVALID OWRAPPER)
1148 ;;; :UNINITIALIZED)))
1150 ;;; Thanks to Gerd Moellmann for the explanation. -- CSR, 2002-10-29
1151 (defun force-cache-flushes (class)
1152 (let* ((owrapper (class-wrapper class)))
1153 ;; We only need to do something if the wrapper is still valid. If
1154 ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
1155 ;; both of those will already be doing what we want. In
1156 ;; particular, we must be sure we never change an OBSOLETE into a
1157 ;; FLUSH since OBSOLETE means do what FLUSH does and then some.
1158 (when (or (not (invalid-wrapper-p owrapper))
1159 ;; KLUDGE: despite the observations above, this remains
1160 ;; a violation of locality or what might be considered
1161 ;; good style. There has to be a better way! -- CSR,
1163 (eq (layout-invalid owrapper) t))
1164 (let ((nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1166 (setf (wrapper-instance-slots-layout nwrapper)
1167 (wrapper-instance-slots-layout owrapper))
1168 (setf (wrapper-class-slots nwrapper)
1169 (wrapper-class-slots owrapper))
1171 (update-lisp-class-layout class nwrapper)
1172 (setf (slot-value class 'wrapper) nwrapper)
1173 (invalidate-wrapper owrapper :flush nwrapper))))))
1175 (defun flush-cache-trap (owrapper nwrapper instance)
1176 (declare (ignore owrapper))
1177 (set-wrapper instance nwrapper))
1179 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
1180 ;;; the next access to the instance (as defined in 88-002R) to trap
1181 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
1182 (defmethod make-instances-obsolete ((class std-class))
1183 (let* ((owrapper (class-wrapper class))
1184 (nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1186 (setf (wrapper-instance-slots-layout nwrapper)
1187 (wrapper-instance-slots-layout owrapper))
1188 (setf (wrapper-class-slots nwrapper)
1189 (wrapper-class-slots owrapper))
1191 (update-lisp-class-layout class nwrapper)
1192 (setf (slot-value class 'wrapper) nwrapper)
1193 (invalidate-wrapper owrapper :obsolete nwrapper)
1196 (defmethod make-instances-obsolete ((class symbol))
1197 (make-instances-obsolete (find-class class)))
1199 ;;; OBSOLETE-INSTANCE-TRAP is the internal trap that is called when we
1200 ;;; see an obsolete instance. The times when it is called are:
1201 ;;; - when the instance is involved in method lookup
1202 ;;; - when attempting to access a slot of an instance
1204 ;;; It is not called by class-of, wrapper-of, or any of the low-level
1205 ;;; instance access macros.
1207 ;;; Of course these times when it is called are an internal
1208 ;;; implementation detail of PCL and are not part of the documented
1209 ;;; description of when the obsolete instance update happens. The
1210 ;;; documented description is as it appears in 88-002R.
1212 ;;; This has to return the new wrapper, so it counts on all the
1213 ;;; methods on obsolete-instance-trap-internal to return the new
1214 ;;; wrapper. It also does a little internal error checking to make
1215 ;;; sure that the traps are only happening when they should, and that
1216 ;;; the trap methods are computing appropriate new wrappers.
1218 ;;; OBSOLETE-INSTANCE-TRAP might be called on structure instances
1219 ;;; after a structure is redefined. In most cases,
1220 ;;; OBSOLETE-INSTANCE-TRAP will not be able to fix the old instance,
1221 ;;; so it must signal an error. The hard part of this is that the
1222 ;;; error system and debugger might cause OBSOLETE-INSTANCE-TRAP to be
1223 ;;; called again, so in that case, we have to return some reasonable
1224 ;;; wrapper, instead.
1226 (defvar *in-obsolete-instance-trap* nil)
1227 (defvar *the-wrapper-of-structure-object*
1228 (class-wrapper (find-class 'structure-object)))
1230 (define-condition obsolete-structure (error)
1231 ((datum :reader obsolete-structure-datum :initarg :datum))
1233 (lambda (condition stream)
1234 ;; Don't try to print the structure, since it probably won't work.
1236 "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
1237 (type-of (obsolete-structure-datum condition))))))
1239 (defun obsolete-instance-trap (owrapper nwrapper instance)
1240 (if (not (pcl-instance-p instance))
1241 (if *in-obsolete-instance-trap*
1242 *the-wrapper-of-structure-object*
1243 (let ((*in-obsolete-instance-trap* t))
1244 (error 'obsolete-structure :datum instance)))
1245 (let* ((class (wrapper-class* nwrapper))
1246 (copy (allocate-instance class)) ;??? allocate-instance ???
1247 (olayout (wrapper-instance-slots-layout owrapper))
1248 (nlayout (wrapper-instance-slots-layout nwrapper))
1249 (oslots (get-slots instance))
1250 (nslots (get-slots copy))
1251 (oclass-slots (wrapper-class-slots owrapper))
1255 ;; local --> local transfer
1256 ;; local --> shared discard
1257 ;; local --> -- discard
1258 ;; shared --> local transfer
1259 ;; shared --> shared discard
1260 ;; shared --> -- discard
1264 ;; Go through all the old local slots.
1266 (dolist (name olayout)
1267 (let ((npos (posq name nlayout)))
1269 (setf (clos-slots-ref nslots npos)
1270 (clos-slots-ref oslots opos))
1272 (push name discarded)
1273 (unless (eq (clos-slots-ref oslots opos) +slot-unbound+)
1274 (setf (getf plist name) (clos-slots-ref oslots opos))))))
1277 ;; Go through all the old shared slots.
1278 (dolist (oclass-slot-and-val oclass-slots)
1279 (let ((name (car oclass-slot-and-val))
1280 (val (cdr oclass-slot-and-val)))
1281 (let ((npos (posq name nlayout)))
1283 (setf (clos-slots-ref nslots npos) (cdr oclass-slot-and-val))
1284 (progn (push name discarded)
1285 (unless (eq val +slot-unbound+)
1286 (setf (getf plist name) val)))))))
1288 ;; Go through all the new local slots to compute the added slots.
1289 (dolist (nlocal nlayout)
1290 (unless (or (memq nlocal olayout)
1291 (assq nlocal oclass-slots))
1292 (push nlocal added)))
1294 (swap-wrappers-and-slots instance copy)
1296 (update-instance-for-redefined-class instance
1302 (defun change-class-internal (instance new-class initargs)
1303 (let* ((old-class (class-of instance))
1304 (copy (allocate-instance new-class))
1305 (new-wrapper (get-wrapper copy))
1306 (old-wrapper (class-wrapper old-class))
1307 (old-layout (wrapper-instance-slots-layout old-wrapper))
1308 (new-layout (wrapper-instance-slots-layout new-wrapper))
1309 (old-slots (get-slots instance))
1310 (new-slots (get-slots copy))
1311 (old-class-slots (wrapper-class-slots old-wrapper)))
1313 ;; "The values of local slots specified by both the class CTO and
1314 ;; CFROM are retained. If such a local slot was unbound, it
1315 ;; remains unbound."
1316 (let ((new-position 0))
1317 (dolist (new-slot new-layout)
1318 (let ((old-position (posq new-slot old-layout)))
1320 (setf (clos-slots-ref new-slots new-position)
1321 (clos-slots-ref old-slots old-position))))
1322 (incf new-position)))
1324 ;; "The values of slots specified as shared in the class CFROM and
1325 ;; as local in the class CTO are retained."
1326 (dolist (slot-and-val old-class-slots)
1327 (let ((position (posq (car slot-and-val) new-layout)))
1329 (setf (clos-slots-ref new-slots position) (cdr slot-and-val)))))
1331 ;; Make the copy point to the old instance's storage, and make the
1332 ;; old instance point to the new storage.
1333 (swap-wrappers-and-slots instance copy)
1335 (apply #'update-instance-for-different-class copy instance initargs)
1338 (defmethod change-class ((instance standard-object)
1339 (new-class standard-class)
1341 (change-class-internal instance new-class initargs))
1343 (defmethod change-class ((instance funcallable-standard-object)
1344 (new-class funcallable-standard-class)
1346 (change-class-internal instance new-class initargs))
1348 (defmethod change-class ((instance standard-object)
1349 (new-class funcallable-standard-class)
1351 (declare (ignore initargs))
1352 (error "You can't change the class of ~S to ~S~@
1353 because it isn't already an instance with metaclass ~S."
1354 instance new-class 'standard-class))
1356 (defmethod change-class ((instance funcallable-standard-object)
1357 (new-class standard-class)
1359 (declare (ignore initargs))
1360 (error "You can't change the class of ~S to ~S~@
1361 because it isn't already an instance with metaclass ~S."
1362 instance new-class 'funcallable-standard-class))
1364 (defmethod change-class ((instance t) (new-class-name symbol) &rest initargs)
1365 (apply #'change-class instance (find-class new-class-name) initargs))
1367 ;;;; The metaclass BUILT-IN-CLASS
1369 ;;;; This metaclass is something of a weird creature. By this point, all
1370 ;;;; instances of it which will exist have been created, and no instance
1371 ;;;; is ever created by calling MAKE-INSTANCE.
1373 ;;;; But, there are other parts of the protocol we must follow and those
1374 ;;;; definitions appear here.
1376 (defmethod shared-initialize :before
1377 ((class built-in-class) slot-names &rest initargs)
1378 (declare (ignore slot-names initargs))
1379 (error "attempt to initialize or reinitialize a built in class"))
1381 (defmethod class-direct-slots ((class built-in-class)) ())
1382 (defmethod class-slots ((class built-in-class)) ())
1383 (defmethod class-direct-default-initargs ((class built-in-class)) ())
1384 (defmethod class-default-initargs ((class built-in-class)) ())
1386 (defmethod validate-superclass ((c class) (s built-in-class))
1387 (or (eq s *the-class-t*)
1388 (eq s *the-class-stream*)))
1390 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
1391 (defmethod class-direct-slots ((class forward-referenced-class)) ())
1392 (defmethod class-direct-default-initargs ((class forward-referenced-class)) ())
1393 (macrolet ((def (method)
1394 `(defmethod ,method ((class forward-referenced-class))
1395 (error "~@<~I~S was called on a forward referenced class:~2I~_~S~:>"
1397 (def class-default-initargs)
1398 (def class-precedence-list)
1401 (defmethod validate-superclass ((c slot-class)
1402 (f forward-referenced-class))
1405 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
1406 (pushnew dependent (plist-value metaobject 'dependents)))
1408 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
1409 (setf (plist-value metaobject 'dependents)
1410 (delete dependent (plist-value metaobject 'dependents))))
1412 (defmethod map-dependents ((metaobject dependent-update-mixin) function)
1413 (dolist (dependent (plist-value metaobject 'dependents))
1414 (funcall function dependent)))