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 ;;; CMUCL (Gerd PCL 2003-04-25) comment:
91 ;;; Compute an effective method for SLOT-VALUE-USING-CLASS, (SETF
92 ;;; SLOT-VALUE-USING-CLASS) or SLOT-BOUNDP-USING-CLASS for reading/
93 ;;; writing/testing effective slot SLOTD.
95 ;;; TYPE is one of the symbols READER, WRITER or BOUNDP, depending on
96 ;;; GF. Store the effective method in the effective slot definition
97 ;;; object itself; these GFs have special dispatch functions calling
98 ;;; effective methods directly retrieved from effective slot
99 ;;; definition objects, as an optimization.
101 ;;; FIXME: Change the function name to COMPUTE-SVUC-SLOTD-FUNCTION,
103 (defmethod compute-slot-accessor-info ((slotd effective-slot-definition)
105 (let* ((name (slot-value slotd 'name))
106 (class (slot-value slotd 'class))
107 (old-slotd (find-slot-definition class name))
108 (old-std-p (and old-slotd (slot-accessor-std-p old-slotd 'all))))
109 (multiple-value-bind (function std-p)
110 (if (eq *boot-state* 'complete)
111 (get-accessor-method-function gf type class slotd)
112 (get-optimized-std-accessor-method-function class slotd type))
113 (setf (slot-accessor-std-p slotd type) std-p)
114 (setf (slot-accessor-function slotd type) function))
115 (when (and old-slotd (not (eq old-std-p (slot-accessor-std-p slotd 'all))))
116 (push (cons class name) *pv-table-cache-update-info*))))
118 (defmethod slot-definition-allocation ((slotd structure-slot-definition))
121 ;;;; various class accessors that are a little more complicated than can be
122 ;;;; done with automatically generated reader methods
124 (defmethod class-prototype :before (class)
125 (unless (class-finalized-p class)
126 (error "~S not yet finalized, cannot allocate a prototype." class)))
128 ;;; KLUDGE: For some reason factoring the common body into a function
129 ;;; breaks PCL bootstrapping, so just generate it with a macrolet for
131 (macrolet ((def (class)
132 `(defmethod class-prototype ((class ,class))
133 (with-slots (prototype) class
135 (setf prototype (allocate-instance class)))))))
137 (def condition-class)
138 (def structure-class))
140 (defmethod class-direct-default-initargs ((class slot-class))
141 (plist-value class 'direct-default-initargs))
143 (defmethod class-default-initargs ((class slot-class))
144 (plist-value class 'default-initargs))
146 (defmethod class-slot-cells ((class std-class))
147 (plist-value class 'class-slot-cells))
148 (defmethod (setf class-slot-cells) (new-value (class std-class))
149 (setf (plist-value class 'class-slot-cells) new-value))
151 ;;;; class accessors that are even a little bit more complicated than those
152 ;;;; above. These have a protocol for updating them, we must implement that
155 ;;; Maintaining the direct subclasses backpointers. The update methods are
156 ;;; here, the values are read by an automatically generated reader method.
157 (defmethod add-direct-subclass ((class class) (subclass class))
158 (with-slots (direct-subclasses) class
159 (pushnew subclass direct-subclasses)
161 (defmethod remove-direct-subclass ((class class) (subclass class))
162 (with-slots (direct-subclasses) class
163 (setq direct-subclasses (remove subclass direct-subclasses))
166 ;;; Maintaining the direct-methods and direct-generic-functions backpointers.
168 ;;; There are four generic functions involved, each has one method for the
169 ;;; class case and another method for the damned EQL specializers. All of
170 ;;; these are specified methods and appear in their specified place in the
173 ;;; ADD-DIRECT-METHOD
174 ;;; REMOVE-DIRECT-METHOD
175 ;;; SPECIALIZER-DIRECT-METHODS
176 ;;; SPECIALIZER-DIRECT-GENERIC-FUNCTIONS
178 ;;; In each case, we maintain one value which is a cons. The car is the list
179 ;;; methods. The cdr is a list of the generic functions. The cdr is always
181 (defmethod add-direct-method ((specializer class) (method method))
182 (with-slots (direct-methods) specializer
183 (setf (car direct-methods) (adjoin method (car direct-methods)) ;PUSH
184 (cdr direct-methods) ()))
186 (defmethod remove-direct-method ((specializer class) (method method))
187 (with-slots (direct-methods) specializer
188 (setf (car direct-methods) (remove method (car direct-methods))
189 (cdr direct-methods) ()))
192 (defmethod specializer-direct-methods ((specializer class))
193 (with-slots (direct-methods) specializer
194 (car direct-methods)))
196 (defmethod specializer-direct-generic-functions ((specializer class))
197 (with-slots (direct-methods) specializer
198 (or (cdr direct-methods)
199 (setf (cdr direct-methods)
201 (dolist (m (car direct-methods))
202 ;; the old PCL code used COLLECTING-ONCE which used
203 ;; #'EQ to check for newness
204 (pushnew (method-generic-function m) collect :test #'eq))
205 (nreverse collect))))))
207 ;;; This hash table is used to store the direct methods and direct generic
208 ;;; functions of EQL specializers. Each value in the table is the cons.
209 (defvar *eql-specializer-methods* (make-hash-table :test 'eql))
210 (defvar *class-eq-specializer-methods* (make-hash-table :test 'eq))
212 (defmethod specializer-method-table ((specializer eql-specializer))
213 *eql-specializer-methods*)
215 (defmethod specializer-method-table ((specializer class-eq-specializer))
216 *class-eq-specializer-methods*)
218 (defmethod add-direct-method ((specializer specializer-with-object)
220 (let* ((object (specializer-object specializer))
221 (table (specializer-method-table specializer))
222 (entry (gethash object table)))
225 (setf (gethash object table)
227 (setf (car entry) (adjoin method (car entry))
231 (defmethod remove-direct-method ((specializer specializer-with-object)
233 (let* ((object (specializer-object specializer))
234 (entry (gethash object (specializer-method-table specializer))))
236 (setf (car entry) (remove method (car entry))
240 (defmethod specializer-direct-methods ((specializer specializer-with-object))
241 (car (gethash (specializer-object specializer)
242 (specializer-method-table specializer))))
244 (defmethod specializer-direct-generic-functions ((specializer
245 specializer-with-object))
246 (let* ((object (specializer-object specializer))
247 (entry (gethash object (specializer-method-table specializer))))
252 (dolist (m (car entry))
253 (pushnew (method-generic-function m) collect :test #'eq))
254 (nreverse collect)))))))
256 (defun map-specializers (function)
257 (map-all-classes (lambda (class)
258 (funcall function (class-eq-specializer class))
259 (funcall function class)))
260 (maphash (lambda (object methods)
261 (declare (ignore methods))
262 (intern-eql-specializer object))
263 *eql-specializer-methods*)
264 (maphash (lambda (object specl)
265 (declare (ignore object))
266 (funcall function specl))
267 *eql-specializer-table*)
270 (defun map-all-generic-functions (function)
271 (let ((all-generic-functions (make-hash-table :test 'eq)))
272 (map-specializers (lambda (specl)
273 (dolist (gf (specializer-direct-generic-functions
275 (unless (gethash gf all-generic-functions)
276 (setf (gethash gf all-generic-functions) t)
277 (funcall function gf))))))
280 (defmethod shared-initialize :after ((specl class-eq-specializer)
283 (declare (ignore slot-names))
284 (setf (slot-value specl 'type) `(class-eq ,(specializer-class specl))))
286 (defmethod shared-initialize :after ((specl eql-specializer) slot-names &key)
287 (declare (ignore slot-names))
288 (setf (slot-value specl 'type)
289 `(eql ,(specializer-object specl)))
290 (setf (info :type :translator specl)
291 (constantly (make-member-type :members (list (specializer-object specl))))))
293 (defun real-load-defclass (name metaclass-name supers slots other
294 readers writers slot-names)
295 (with-single-package-locked-error (:symbol name "defining ~S as a class")
296 (%compiler-defclass name readers writers slot-names)
297 (let ((res (apply #'ensure-class name :metaclass metaclass-name
298 :direct-superclasses supers
300 :definition-source `((defclass ,name)
305 (setf (gdefinition 'load-defclass) #'real-load-defclass)
307 (defun ensure-class (name &rest args)
308 (apply #'ensure-class-using-class
309 (let ((class (find-class name nil)))
310 (when (and class (eq name (class-name class)))
311 ;; NAME is the proper name of CLASS, so redefine it
316 (defmethod ensure-class-using-class ((class null) name &rest args &key)
317 (multiple-value-bind (meta initargs)
318 (ensure-class-values class args)
319 (set-class-type-translation (class-prototype meta) name)
320 (setf class (apply #'make-instance meta :name name initargs))
321 (without-package-locks
322 (setf (find-class name) class))
323 (set-class-type-translation class name)
326 (defmethod ensure-class-using-class ((class pcl-class) name &rest args &key)
327 (multiple-value-bind (meta initargs)
328 (ensure-class-values class args)
329 (unless (eq (class-of class) meta)
330 (apply #'change-class class meta initargs))
331 (apply #'reinitialize-instance class initargs)
332 (without-package-locks
333 (setf (find-class name) class))
334 (set-class-type-translation class name)
337 (defmethod class-predicate-name ((class t))
342 ((not (legal-class-name-p s))
343 (error "~S is not a class or a legal class name." s))
345 (or (find-class s nil)
346 (make-instance 'forward-referenced-class
349 (defun ensure-class-values (class initargs)
350 (let (metaclass metaclassp reversed-plist)
351 (doplist (key val) initargs
352 (cond ((eq key :metaclass)
356 (when (eq key :direct-superclasses)
357 (setf val (mapcar #'fix-super val)))
358 (setf reversed-plist (list* val key reversed-plist)))))
359 (values (cond (metaclassp
360 (find-class metaclass))
361 ((or (null class) (forward-referenced-class-p class))
362 *the-class-standard-class*)
365 (nreverse reversed-plist))))
368 (defmethod shared-initialize :after
371 &key (direct-superclasses nil direct-superclasses-p)
372 (direct-slots nil direct-slots-p)
373 (direct-default-initargs nil direct-default-initargs-p)
374 (predicate-name nil predicate-name-p))
375 (cond (direct-superclasses-p
376 (setq direct-superclasses
377 (or direct-superclasses
378 (list (if (funcallable-standard-class-p class)
379 *the-class-funcallable-standard-object*
380 *the-class-standard-object*))))
381 (dolist (superclass direct-superclasses)
382 (unless (validate-superclass class superclass)
383 (error "The class ~S was specified as a~%
384 super-class of the class ~S;~%~
385 but the meta-classes ~S and~%~S are incompatible.~@
386 Define a method for ~S to avoid this error."
387 superclass class (class-of superclass) (class-of class)
388 'validate-superclass)))
389 (setf (slot-value class 'direct-superclasses) direct-superclasses))
391 (setq direct-superclasses (slot-value class 'direct-superclasses))))
394 (setf (slot-value class 'direct-slots)
395 (mapcar (lambda (pl) (make-direct-slotd class pl))
397 (slot-value class 'direct-slots)))
398 (if direct-default-initargs-p
399 (setf (plist-value class 'direct-default-initargs)
400 direct-default-initargs)
401 (setq direct-default-initargs
402 (plist-value class 'direct-default-initargs)))
403 (setf (plist-value class 'class-slot-cells)
404 (let ((old-class-slot-cells (plist-value class 'class-slot-cells))
406 (dolist (dslotd direct-slots)
407 (when (eq :class (slot-definition-allocation dslotd))
409 (let* ((name (slot-definition-name dslotd))
410 (old (assoc name old-class-slot-cells)))
413 (member name slot-names))
414 (let* ((initfunction (slot-definition-initfunction dslotd))
415 (value (if initfunction
416 (funcall initfunction)
418 (push (cons name value) collect))
419 (push old collect)))))
421 (setq predicate-name (if predicate-name-p
422 (setf (slot-value class 'predicate-name)
423 (car predicate-name))
424 (or (slot-value class 'predicate-name)
425 (setf (slot-value class 'predicate-name)
426 (make-class-predicate-name (class-name
428 (add-direct-subclasses class direct-superclasses)
429 (make-class-predicate class predicate-name)
430 (update-class class nil)
431 (do* ((slots (slot-value class 'slots) (cdr slots))
433 ((null slots) (when dupes
435 ;; FIXME: the indentation request ("~4I")
436 ;; below appears not to do anything. Finding
437 ;; out why would be nice. -- CSR, 2003-04-24
438 "~@<slot names with the same SYMBOL-NAME but ~
439 different SYMBOL-PACKAGE (possible package problem) ~
440 for class ~S:~@:_~4I~<~@{~S~^~:@_~}~:>~@:>"
443 (let* ((slot (car slots))
444 (oslots (remove (slot-definition-name slot) (cdr slots)
445 :test #'string/= :key #'slot-definition-name)))
447 (pushnew (cons (slot-definition-name slot)
448 (mapcar #'slot-definition-name oslots))
450 :test #'string= :key #'car))))
451 (add-slot-accessors class direct-slots)
452 (make-preliminary-layout class))
454 (defmethod shared-initialize :after ((class forward-referenced-class)
455 slot-names &key &allow-other-keys)
456 (declare (ignore slot-names))
457 (make-preliminary-layout class))
459 (defvar *allow-forward-referenced-classes-in-cpl-p* nil)
461 ;;; Give CLASS a preliminary layout if it doesn't have one already, to
462 ;;; make it known to the type system.
463 (defun make-preliminary-layout (class)
464 (flet ((compute-preliminary-cpl (root)
465 (let ((*allow-forward-referenced-classes-in-cpl-p* t))
466 (compute-class-precedence-list root))))
467 (without-package-locks
468 (unless (class-finalized-p class)
469 (let ((name (class-name class)))
470 (setf (find-class name) class)
471 ;; KLUDGE: This is fairly horrible. We need to make a
472 ;; full-fledged CLASSOID here, not just tell the compiler that
473 ;; some class is forthcoming, because there are legitimate
474 ;; questions one can ask of the type system, implemented in
475 ;; terms of CLASSOIDs, involving forward-referenced classes. So.
476 (when (and (eq *boot-state* 'complete)
477 (null (find-classoid name nil)))
478 (setf (find-classoid name)
479 (make-standard-classoid :name name)))
480 (set-class-type-translation class name)
481 (let ((layout (make-wrapper 0 class))
482 (classoid (find-classoid name)))
483 (setf (layout-classoid layout) classoid)
484 (setf (classoid-pcl-class classoid) class)
485 (setf (slot-value class 'wrapper) layout)
486 (let ((cpl (compute-preliminary-cpl class)))
487 (setf (layout-inherits layout)
488 (order-layout-inherits
489 (map 'simple-vector #'class-wrapper
490 (reverse (rest cpl))))))
491 (register-layout layout :invalidate t)
492 (setf (classoid-layout classoid) layout)
493 (mapc #'make-preliminary-layout (class-direct-subclasses class))))))))
496 (defmethod shared-initialize :before ((class class) slot-names &key name)
497 (declare (ignore slot-names name))
498 ;; FIXME: Could this just be CLASS instead of `(CLASS ,CLASS)? If not,
499 ;; why not? (See also similar expression in !BOOTSTRAP-INITIALIZE-CLASS.)
500 (setf (slot-value class 'type) `(class ,class))
501 (setf (slot-value class 'class-eq-specializer)
502 (make-instance 'class-eq-specializer :class class)))
504 (defmethod reinitialize-instance :before ((class slot-class) &key)
505 (remove-direct-subclasses class (class-direct-superclasses class))
506 (remove-slot-accessors class (class-direct-slots class)))
508 (defmethod reinitialize-instance :after ((class slot-class)
511 (map-dependents class
513 (apply #'update-dependent class dependent initargs))))
515 (defmethod shared-initialize :after ((class condition-class) slot-names
516 &key direct-slots direct-superclasses)
517 (declare (ignore slot-names))
518 (let ((classoid (find-classoid (class-name class))))
519 (with-slots (wrapper class-precedence-list cpl-available-p
520 prototype predicate-name
521 (direct-supers direct-superclasses))
523 (setf (slot-value class 'direct-slots)
524 (mapcar (lambda (pl) (make-direct-slotd class pl))
526 (setf (slot-value class 'finalized-p) t)
527 (setf (classoid-pcl-class classoid) class)
528 (setq direct-supers direct-superclasses)
529 (setq wrapper (classoid-layout classoid))
530 (setq class-precedence-list (compute-class-precedence-list class))
531 (setq cpl-available-p t)
532 (add-direct-subclasses class direct-superclasses)
533 (setq predicate-name (make-class-predicate-name (class-name class)))
534 (make-class-predicate class predicate-name)
535 (setf (slot-value class 'slots) (compute-slots class))))
536 ;; Comment from Gerd's PCL, 2003-05-15:
538 ;; We don't ADD-SLOT-ACCESSORS here because we don't want to
539 ;; override condition accessors with generic functions. We do this
541 (update-pv-table-cache-info class))
543 (defmethod direct-slot-definition-class ((class condition-class)
545 (declare (ignore initargs))
546 (find-class 'condition-direct-slot-definition))
548 (defmethod effective-slot-definition-class ((class condition-class)
550 (declare (ignore initargs))
551 (find-class 'condition-effective-slot-definition))
553 (defmethod finalize-inheritance ((class condition-class))
554 (aver (slot-value class 'finalized-p))
557 (defmethod compute-effective-slot-definition
558 ((class condition-class) slot-name dslotds)
559 (let ((slotd (call-next-method)))
560 (setf (slot-definition-reader-function slotd)
562 (handler-case (condition-reader-function x slot-name)
563 ;; FIXME: FIND-SLOT-DEFAULT throws an error if the slot
564 ;; is unbound; maybe it should be a CELL-ERROR of some
566 (error () (values (slot-unbound class x slot-name))))))
567 (setf (slot-definition-writer-function slotd)
569 (condition-writer-function x v slot-name)))
570 (setf (slot-definition-boundp-function slotd)
572 (multiple-value-bind (v c)
573 (ignore-errors (condition-reader-function x slot-name))
578 (defmethod compute-slots ((class condition-class))
579 (mapcan (lambda (superclass)
580 (mapcar (lambda (dslotd)
581 (compute-effective-slot-definition
582 class (slot-definition-name dslotd) (list dslotd)))
583 (class-direct-slots superclass)))
584 (reverse (slot-value class 'class-precedence-list))))
586 (defmethod compute-slots :around ((class condition-class))
587 (let ((eslotds (call-next-method)))
588 (mapc #'initialize-internal-slot-functions eslotds)
591 (defmethod shared-initialize :after
592 ((slotd structure-slot-definition) slot-names &key
593 (allocation :instance) allocation-class)
594 (declare (ignore slot-names allocation-class))
595 (unless (eq allocation :instance)
596 (error "Structure slots must have :INSTANCE allocation.")))
598 (defun make-structure-class-defstruct-form (name direct-slots include)
599 (let* ((conc-name (format-symbol *package* "~S structure class " name))
600 (constructor (format-symbol *package* "~Aconstructor" conc-name))
601 (defstruct `(defstruct (,name
603 `((:include ,(class-name include))))
605 (:conc-name ,conc-name)
606 (:constructor ,constructor ())
608 ,@(mapcar (lambda (slot)
609 `(,(slot-definition-name slot)
612 (reader-names (mapcar (lambda (slotd)
613 (list 'slot-accessor name
614 (slot-definition-name slotd)
617 (writer-names (mapcar (lambda (slotd)
618 (list 'slot-accessor name
619 (slot-definition-name slotd)
623 (mapcar (lambda (slotd reader-name)
625 (slot-definition-defstruct-accessor-symbol
627 `(defun ,reader-name (obj)
628 (declare (type ,name obj))
630 direct-slots reader-names))
632 (mapcar (lambda (slotd writer-name)
634 (slot-definition-defstruct-accessor-symbol
636 `(defun ,writer-name (nv obj)
637 (declare (type ,name obj))
638 (setf (,accessor obj) nv))))
639 direct-slots writer-names))
643 ,@readers-init ,@writers-init
645 (values defstruct-form constructor reader-names writer-names)))
647 (defun make-defstruct-allocation-function (class)
648 (let ((dd (get-structure-dd (class-name class))))
650 (let ((instance (%make-instance (dd-length dd)))
651 (raw-index (dd-raw-index dd)))
652 (setf (%instance-layout instance)
653 (sb-kernel::compiler-layout-or-lose (dd-name dd)))
655 (setf (%instance-ref instance raw-index)
656 (make-array (dd-raw-length dd)
657 :element-type '(unsigned-byte 32))))
660 (defmethod shared-initialize :after
661 ((class structure-class)
663 &key (direct-superclasses nil direct-superclasses-p)
664 (direct-slots nil direct-slots-p)
665 direct-default-initargs
666 (predicate-name nil predicate-name-p))
667 (declare (ignore slot-names direct-default-initargs))
668 (if direct-superclasses-p
669 (setf (slot-value class 'direct-superclasses)
670 (or direct-superclasses
671 (setq direct-superclasses
672 (and (not (eq (class-name class) 'structure-object))
673 (list *the-class-structure-object*)))))
674 (setq direct-superclasses (slot-value class 'direct-superclasses)))
675 (let* ((name (class-name class))
676 (from-defclass-p (slot-value class 'from-defclass-p))
677 (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
679 (setf (slot-value class 'direct-slots)
683 (let* ((slot-name (getf pl :name))
685 (format-symbol *package*
686 "~S structure class ~A"
688 (setq pl (list* :defstruct-accessor-symbol
690 (make-direct-slotd class pl))
692 (setq direct-slots (slot-value class 'direct-slots)))
694 (let ((include (car (slot-value class 'direct-superclasses))))
695 (multiple-value-bind (defstruct-form constructor reader-names writer-names)
696 (make-structure-class-defstruct-form name direct-slots include)
697 (unless (structure-type-p name) (eval defstruct-form))
698 (mapc (lambda (dslotd reader-name writer-name)
699 (let* ((reader (gdefinition reader-name))
700 (writer (when (gboundp writer-name)
701 (gdefinition writer-name))))
702 (setf (slot-value dslotd 'internal-reader-function)
704 (setf (slot-value dslotd 'internal-writer-function)
706 direct-slots reader-names writer-names)
707 (setf (slot-value class 'defstruct-form) defstruct-form)
708 (setf (slot-value class 'defstruct-constructor) constructor)))
709 (setf (slot-value class 'defstruct-constructor)
710 (make-defstruct-allocation-function class)))
711 (add-direct-subclasses class direct-superclasses)
712 (setf (slot-value class 'class-precedence-list)
713 (compute-class-precedence-list class))
714 (setf (slot-value class 'cpl-available-p) t)
715 (setf (slot-value class 'slots) (compute-slots class))
716 (let ((lclass (find-classoid (class-name class))))
717 (setf (classoid-pcl-class lclass) class)
718 (setf (slot-value class 'wrapper) (classoid-layout lclass)))
719 (setf (slot-value class 'finalized-p) t)
720 (update-pv-table-cache-info class)
721 (setq predicate-name (if predicate-name-p
722 (setf (slot-value class 'predicate-name)
723 (car predicate-name))
724 (or (slot-value class 'predicate-name)
725 (setf (slot-value class 'predicate-name)
726 (make-class-predicate-name
727 (class-name class))))))
728 (make-class-predicate class predicate-name)
729 (add-slot-accessors class direct-slots)))
731 (defmethod direct-slot-definition-class ((class structure-class) &rest initargs)
732 (declare (ignore initargs))
733 (find-class 'structure-direct-slot-definition))
735 (defmethod finalize-inheritance ((class structure-class))
736 nil) ; always finalized
738 (defun add-slot-accessors (class dslotds)
739 (fix-slot-accessors class dslotds 'add))
741 (defun remove-slot-accessors (class dslotds)
742 (fix-slot-accessors class dslotds 'remove))
744 (defun fix-slot-accessors (class dslotds add/remove)
745 (flet ((fix (gfspec name r/w)
746 (let ((gf (if (fboundp gfspec)
747 (without-package-locks
748 (ensure-generic-function gfspec))
749 (ensure-generic-function
750 gfspec :lambda-list (case r/w
752 (w '(new-value object)))))))
754 (r (if (eq add/remove 'add)
755 (add-reader-method class gf name)
756 (remove-reader-method class gf)))
757 (w (if (eq add/remove 'add)
758 (add-writer-method class gf name)
759 (remove-writer-method class gf)))))))
760 (dolist (dslotd dslotds)
761 (let ((slot-name (slot-definition-name dslotd)))
762 (dolist (r (slot-definition-readers dslotd))
763 (fix r slot-name 'r))
764 (dolist (w (slot-definition-writers dslotd))
765 (fix w slot-name 'w))))))
767 (defun add-direct-subclasses (class supers)
768 (dolist (super supers)
769 (unless (memq class (class-direct-subclasses class))
770 (add-direct-subclass super class))))
772 (defun remove-direct-subclasses (class supers)
773 (let ((old (class-direct-superclasses class)))
774 (dolist (o (set-difference old supers))
775 (remove-direct-subclass o class))))
777 (defmethod finalize-inheritance ((class std-class))
778 (update-class class t))
780 (defmethod finalize-inheritance ((class forward-referenced-class))
781 ;; FIXME: should we not be thinking a bit about what kinds of error
782 ;; we're throwing? Maybe we need a clos-error type to mix in? Or
783 ;; possibly a forward-referenced-class-error, though that's
784 ;; difficult given e.g. class precedence list calculations...
786 "~@<FINALIZE-INHERITANCE was called on a forward referenced class:~
791 (defun class-has-a-forward-referenced-superclass-p (class)
792 (or (forward-referenced-class-p class)
793 (some #'class-has-a-forward-referenced-superclass-p
794 (class-direct-superclasses class))))
796 ;;; This is called by :after shared-initialize whenever a class is initialized
797 ;;; or reinitialized. The class may or may not be finalized.
798 (defun update-class (class finalizep)
799 ;; Comment from Gerd Moellmann:
801 ;; Note that we can't simply delay the finalization when CLASS has
802 ;; no forward referenced superclasses because that causes bootstrap
804 (without-package-locks
805 (when (and (not finalizep)
806 (not (class-finalized-p class))
807 (not (class-has-a-forward-referenced-superclass-p class)))
808 (finalize-inheritance class)
809 (return-from update-class))
810 (when (or finalizep (class-finalized-p class)
811 (not (class-has-a-forward-referenced-superclass-p class)))
812 (setf (find-class (class-name class)) class)
813 (update-cpl class (compute-class-precedence-list class))
814 ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
815 ;; class. The hoops above are to ensure that FINALIZE-INHERITANCE
816 ;; is called at finalization, so that MOP programmers can hook
817 ;; into the system as described in "Class Finalization Protocol"
818 ;; (section 5.5.2 of AMOP).
819 (update-slots class (compute-slots class))
820 (update-gfs-of-class class)
821 (update-initargs class (compute-default-initargs class))
822 (update-ctors 'finalize-inheritance :class class))
824 (dolist (sub (class-direct-subclasses class)) (update-class sub nil)))))
826 (defun update-cpl (class cpl)
827 (if (class-finalized-p class)
828 (unless (and (equal (class-precedence-list class) cpl)
830 (when (position :class (class-direct-slots c)
831 :key #'slot-definition-allocation)
833 ;; comment from the old CMU CL sources:
834 ;; Need to have the cpl setup before update-lisp-class-layout
835 ;; is called on CMU CL.
836 (setf (slot-value class 'class-precedence-list) cpl)
837 (setf (slot-value class 'cpl-available-p) t)
838 (force-cache-flushes class))
840 (setf (slot-value class 'class-precedence-list) cpl)
841 (setf (slot-value class 'cpl-available-p) t)))
842 (update-class-can-precede-p cpl))
844 (defun update-class-can-precede-p (cpl)
846 (let ((first (car cpl)))
847 (dolist (c (cdr cpl))
848 (pushnew c (slot-value first 'can-precede-list))))
849 (update-class-can-precede-p (cdr cpl))))
851 (defun class-can-precede-p (class1 class2)
852 (member class2 (class-can-precede-list class1)))
854 (defun update-slots (class eslotds)
855 (let ((instance-slots ())
857 (dolist (eslotd eslotds)
858 (let ((alloc (slot-definition-allocation eslotd)))
860 (:instance (push eslotd instance-slots))
861 (:class (push eslotd class-slots)))))
863 ;; If there is a change in the shape of the instances then the
864 ;; old class is now obsolete.
865 (let* ((nlayout (mapcar #'slot-definition-name
866 (sort instance-slots #'<
867 :key #'slot-definition-location)))
868 (nslots (length nlayout))
869 (nwrapper-class-slots (compute-class-slots class-slots))
870 (owrapper (when (class-finalized-p class)
871 (class-wrapper class)))
872 (olayout (when owrapper
873 (wrapper-instance-slots-layout owrapper)))
874 (owrapper-class-slots (and owrapper (wrapper-class-slots owrapper)))
876 (cond ((null owrapper)
877 (make-wrapper nslots class))
878 ((and (equal nlayout olayout)
880 (loop for o in owrapper-class-slots
881 for n in nwrapper-class-slots
882 do (unless (eq (car o) (car n)) (return t)))))
885 ;; This will initialize the new wrapper to have the
886 ;; same state as the old wrapper. We will then have
887 ;; to change that. This may seem like wasted work
888 ;; (and it is), but the spec requires that we call
889 ;; MAKE-INSTANCES-OBSOLETE.
890 (make-instances-obsolete class)
891 (class-wrapper class)))))
893 (with-slots (wrapper slots) class
894 (update-lisp-class-layout class nwrapper)
896 (wrapper-instance-slots-layout nwrapper) nlayout
897 (wrapper-class-slots nwrapper) nwrapper-class-slots
898 (wrapper-no-of-instance-slots nwrapper) nslots
900 (setf (slot-value class 'finalized-p) t)
901 (unless (eq owrapper nwrapper)
902 (update-pv-table-cache-info class)
903 (maybe-update-standard-class-locations class)))))
905 (defun compute-class-slots (eslotds)
907 (dolist (eslotd eslotds)
908 (push (assoc (slot-definition-name eslotd)
909 (class-slot-cells (slot-definition-class eslotd)))
913 (defun update-gfs-of-class (class)
914 (when (and (class-finalized-p class)
915 (let ((cpl (class-precedence-list class)))
916 (or (member *the-class-slot-class* cpl)
917 (member *the-class-standard-effective-slot-definition*
919 (let ((gf-table (make-hash-table :test 'eq)))
920 (labels ((collect-gfs (class)
921 (dolist (gf (specializer-direct-generic-functions class))
922 (setf (gethash gf gf-table) t))
923 (mapc #'collect-gfs (class-direct-superclasses class))))
925 (maphash (lambda (gf ignore)
926 (declare (ignore ignore))
927 (update-gf-dfun class gf))
930 (defun update-initargs (class inits)
931 (setf (plist-value class 'default-initargs) inits))
933 (defmethod compute-default-initargs ((class slot-class))
934 (let ((initargs (loop for c in (class-precedence-list class)
935 append (class-direct-default-initargs c))))
936 (delete-duplicates initargs :test #'eq :key #'car :from-end t)))
938 ;;;; protocols for constructing direct and effective slot definitions
940 (defmethod direct-slot-definition-class ((class std-class) &rest initargs)
941 (declare (ignore initargs))
942 (find-class 'standard-direct-slot-definition))
944 (defun make-direct-slotd (class initargs)
945 (let ((initargs (list* :class class initargs)))
946 (apply #'make-instance
947 (apply #'direct-slot-definition-class class initargs)
950 (defmethod compute-slots ((class std-class))
951 ;; As specified, we must call COMPUTE-EFFECTIVE-SLOT-DEFINITION once
952 ;; for each different slot name we find in our superclasses. Each
953 ;; call receives the class and a list of the dslotds with that name.
954 ;; The list is in most-specific-first order.
955 (let ((name-dslotds-alist ()))
956 (dolist (c (class-precedence-list class))
957 (dolist (slot (class-direct-slots c))
958 (let* ((name (slot-definition-name slot))
959 (entry (assq name name-dslotds-alist)))
961 (push slot (cdr entry))
962 (push (list name slot) name-dslotds-alist)))))
963 (mapcar (lambda (direct)
964 (compute-effective-slot-definition class
966 (nreverse (cdr direct))))
967 name-dslotds-alist)))
969 (defmethod compute-slots ((class standard-class))
972 (defmethod compute-slots :around ((class standard-class))
973 (let ((eslotds (call-next-method))
975 (dolist (eslotd eslotds eslotds)
976 (setf (slot-definition-location eslotd)
977 (case (slot-definition-allocation eslotd)
981 (let* ((name (slot-definition-name eslotd))
984 (slot-definition-allocation-class eslotd)
985 ;; we get here if the user adds an extra slot
987 (setf (slot-definition-allocation-class eslotd)
989 ;; which raises the question of what we should
990 ;; do if we find that said user has added a slot
991 ;; with the same name as another slot...
992 (cell (or (assq name (class-slot-cells from-class))
993 (setf (class-slot-cells from-class)
994 (cons (cons name +slot-unbound+)
995 (class-slot-cells from-class))))))
997 (if (eq +slot-unbound+ (cdr cell))
998 ;; We may have inherited an initfunction
999 (let ((initfun (slot-definition-initfunction eslotd)))
1001 (rplacd cell (funcall initfun))
1004 (unless (slot-definition-class eslotd)
1005 (setf (slot-definition-class eslotd) class))
1006 (initialize-internal-slot-functions eslotd))))
1008 (defmethod compute-slots ((class funcallable-standard-class))
1011 (defmethod compute-slots :around ((class funcallable-standard-class))
1012 (labels ((instance-slot-names (slotds)
1014 (dolist (slotd slotds (nreverse collect))
1015 (when (eq (slot-definition-allocation slotd) :instance)
1016 (push (slot-definition-name slotd) collect)))))
1017 ;; This sorts slots so that slots of classes later in the CPL
1018 ;; come before slots of other classes. This is crucial for
1019 ;; funcallable instances because it ensures that the slots of
1020 ;; FUNCALLABLE-STANDARD-OBJECT, which includes the slots of
1021 ;; KERNEL:FUNCALLABLE-INSTANCE, come first, which in turn
1022 ;; makes it possible to treat FUNCALLABLE-STANDARD-OBJECT as
1023 ;; a funcallable instance.
1024 (compute-layout (eslotds)
1026 (names (instance-slot-names eslotds)))
1028 (reverse (class-precedence-list class))
1029 (nreverse (nconc names first)))
1030 (dolist (ss (class-slots class))
1031 (let ((name (slot-definition-name ss)))
1032 (when (member name names)
1034 (setq names (delete name names)))))))))
1035 (let ((all-slotds (call-next-method))
1038 (dolist (slotd all-slotds)
1039 (case (slot-definition-allocation slotd)
1040 (:instance (push slotd instance-slots))
1041 (:class (push slotd class-slots))))
1042 (let ((layout (compute-layout instance-slots)))
1043 (dolist (slotd instance-slots)
1044 (setf (slot-definition-location slotd)
1045 (position (slot-definition-name slotd) layout))
1046 (initialize-internal-slot-functions slotd)))
1047 (dolist (slotd class-slots)
1048 (let ((name (slot-definition-name slotd))
1049 (from-class (slot-definition-allocation-class slotd)))
1050 (setf (slot-definition-location slotd)
1051 (assoc name (class-slot-cells from-class)))
1052 (aver (consp (slot-definition-location slotd)))
1053 (initialize-internal-slot-functions slotd)))
1056 (defmethod compute-slots ((class structure-class))
1057 (mapcan (lambda (superclass)
1058 (mapcar (lambda (dslotd)
1059 (compute-effective-slot-definition
1061 (slot-definition-name dslotd)
1063 (class-direct-slots superclass)))
1064 (reverse (slot-value class 'class-precedence-list))))
1066 (defmethod compute-slots :around ((class structure-class))
1067 (let ((eslotds (call-next-method)))
1068 (mapc #'initialize-internal-slot-functions eslotds)
1071 (defmethod compute-effective-slot-definition ((class slot-class) name dslotds)
1072 (declare (ignore name))
1073 (let* ((initargs (compute-effective-slot-definition-initargs class dslotds))
1074 (class (apply #'effective-slot-definition-class class initargs)))
1075 (apply #'make-instance class initargs)))
1077 (defmethod effective-slot-definition-class ((class std-class) &rest initargs)
1078 (declare (ignore initargs))
1079 (find-class 'standard-effective-slot-definition))
1081 (defmethod effective-slot-definition-class ((class structure-class) &rest initargs)
1082 (declare (ignore initargs))
1083 (find-class 'structure-effective-slot-definition))
1085 (defmethod compute-effective-slot-definition-initargs
1086 ((class slot-class) direct-slotds)
1092 (allocation-class nil)
1098 (dolist (slotd direct-slotds)
1101 (setq name (slot-definition-name slotd)
1104 (when (slot-definition-initfunction slotd)
1105 (setq initform (slot-definition-initform slotd)
1106 initfunction (slot-definition-initfunction slotd)
1109 (setq allocation (slot-definition-allocation slotd)
1110 allocation-class (slot-definition-class slotd)
1112 (setq initargs (append (slot-definition-initargs slotd) initargs))
1113 (let ((slotd-type (slot-definition-type slotd)))
1114 (setq type (cond ((eq type t) slotd-type)
1115 ((*subtypep type slotd-type) type)
1116 (t `(and ,type ,slotd-type)))))))
1119 :initfunction initfunction
1121 :allocation allocation
1122 :allocation-class allocation-class
1126 (defmethod compute-effective-slot-definition-initargs :around
1127 ((class structure-class) direct-slotds)
1128 (let ((slotd (car direct-slotds)))
1129 (list* :defstruct-accessor-symbol
1130 (slot-definition-defstruct-accessor-symbol slotd)
1131 :internal-reader-function
1132 (slot-definition-internal-reader-function slotd)
1133 :internal-writer-function
1134 (slot-definition-internal-writer-function slotd)
1135 (call-next-method))))
1137 ;;; NOTE: For bootstrapping considerations, these can't use MAKE-INSTANCE
1138 ;;; to make the method object. They have to use make-a-method which
1139 ;;; is a specially bootstrapped mechanism for making standard methods.
1140 (defmethod reader-method-class ((class slot-class) direct-slot &rest initargs)
1141 (declare (ignore direct-slot initargs))
1142 (find-class 'standard-reader-method))
1144 (defmethod add-reader-method ((class slot-class) generic-function slot-name)
1145 (add-method generic-function
1146 (make-a-method 'standard-reader-method
1148 (list (or (class-name class) 'object))
1150 (make-reader-method-function class slot-name)
1151 "automatically generated reader method"
1154 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
1155 (declare (ignore direct-slot initargs))
1156 (find-class 'standard-writer-method))
1158 (defmethod add-writer-method ((class slot-class) generic-function slot-name)
1159 (add-method generic-function
1160 (make-a-method 'standard-writer-method
1162 (list 'new-value (or (class-name class) 'object))
1163 (list *the-class-t* class)
1164 (make-writer-method-function class slot-name)
1165 "automatically generated writer method"
1168 (defmethod add-boundp-method ((class slot-class) generic-function slot-name)
1169 (add-method generic-function
1170 (make-a-method 'standard-boundp-method
1172 (list (or (class-name class) 'object))
1174 (make-boundp-method-function class slot-name)
1175 "automatically generated boundp method"
1178 (defmethod remove-reader-method ((class slot-class) generic-function)
1179 (let ((method (get-method generic-function () (list class) nil)))
1180 (when method (remove-method generic-function method))))
1182 (defmethod remove-writer-method ((class slot-class) generic-function)
1184 (get-method generic-function () (list *the-class-t* class) nil)))
1185 (when method (remove-method generic-function method))))
1187 (defmethod remove-boundp-method ((class slot-class) generic-function)
1188 (let ((method (get-method generic-function () (list class) nil)))
1189 (when method (remove-method generic-function method))))
1191 ;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITE-METHOD function are NOT
1192 ;;; part of the standard protocol. They are however useful, PCL makes
1193 ;;; use of them internally and documents them for PCL users.
1195 ;;; *** This needs work to make type testing by the writer functions which
1196 ;;; *** do type testing faster. The idea would be to have one constructor
1197 ;;; *** for each possible type test.
1199 ;;; *** There is a subtle bug here which is going to have to be fixed.
1200 ;;; *** Namely, the simplistic use of the template has to be fixed. We
1201 ;;; *** have to give the OPTIMIZE-SLOT-VALUE method the user might have
1202 ;;; *** defined for this metaclass a chance to run.
1204 (defmethod make-reader-method-function ((class slot-class) slot-name)
1205 (make-std-reader-method-function (class-name class) slot-name))
1207 (defmethod make-writer-method-function ((class slot-class) slot-name)
1208 (make-std-writer-method-function (class-name class) slot-name))
1210 (defmethod make-boundp-method-function ((class slot-class) slot-name)
1211 (make-std-boundp-method-function (class-name class) slot-name))
1213 (defmethod compatible-meta-class-change-p (class proto-new-class)
1214 (eq (class-of class) (class-of proto-new-class)))
1216 (defmethod validate-superclass ((class class) (new-super class))
1217 (or (eq new-super *the-class-t*)
1218 (eq (class-of class) (class-of new-super))))
1220 (defmethod validate-superclass ((class standard-class) (new-super std-class))
1221 (let ((new-super-meta-class (class-of new-super)))
1222 (or (eq new-super-meta-class *the-class-std-class*)
1223 (eq (class-of class) new-super-meta-class))))
1225 ;;; What this does depends on which of the four possible values of
1226 ;;; LAYOUT-INVALID the PCL wrapper has; the simplest case is when it
1227 ;;; is (:FLUSH <wrapper>) or (:OBSOLETE <wrapper>), when there is
1228 ;;; nothing to do, as the new wrapper has already been created. If
1229 ;;; LAYOUT-INVALID returns NIL, then we invalidate it (setting it to
1230 ;;; (:FLUSH <wrapper>); UPDATE-SLOTS later gets to choose whether or
1231 ;;; not to "upgrade" this to (:OBSOLETE <wrapper>).
1233 ;;; This leaves the case where LAYOUT-INVALID returns T, which happens
1234 ;;; when REGISTER-LAYOUT has invalidated a superclass of CLASS (which
1235 ;;; invalidated all the subclasses in SB-KERNEL land). Again, here we
1236 ;;; must flush the caches and allow UPDATE-SLOTS to decide whether to
1237 ;;; obsolete the wrapper.
1239 ;;; FIXME: either here or in INVALID-WRAPPER-P looks like a good place
1240 ;;; for (AVER (NOT (EQ (LAYOUT-INVALID OWRAPPER)
1241 ;;; :UNINITIALIZED)))
1243 ;;; Thanks to Gerd Moellmann for the explanation. -- CSR, 2002-10-29
1244 (defun force-cache-flushes (class)
1245 (let* ((owrapper (class-wrapper class)))
1246 ;; We only need to do something if the wrapper is still valid. If
1247 ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
1248 ;; both of those will already be doing what we want. In
1249 ;; particular, we must be sure we never change an OBSOLETE into a
1250 ;; FLUSH since OBSOLETE means do what FLUSH does and then some.
1251 (when (or (not (invalid-wrapper-p owrapper))
1252 ;; KLUDGE: despite the observations above, this remains
1253 ;; a violation of locality or what might be considered
1254 ;; good style. There has to be a better way! -- CSR,
1256 (eq (layout-invalid owrapper) t))
1257 (let ((nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1259 (setf (wrapper-instance-slots-layout nwrapper)
1260 (wrapper-instance-slots-layout owrapper))
1261 (setf (wrapper-class-slots nwrapper)
1262 (wrapper-class-slots owrapper))
1264 (update-lisp-class-layout class nwrapper)
1265 (setf (slot-value class 'wrapper) nwrapper)
1266 ;; Use :OBSOLETE instead of :FLUSH if any superclass has
1268 (if (find-if (lambda (x)
1269 (and (consp x) (eq :obsolete (car x))))
1270 (layout-inherits owrapper)
1271 :key #'layout-invalid)
1272 (invalidate-wrapper owrapper :obsolete nwrapper)
1273 (invalidate-wrapper owrapper :flush nwrapper)))))))
1275 (defun flush-cache-trap (owrapper nwrapper instance)
1276 (declare (ignore owrapper))
1277 (set-wrapper instance nwrapper))
1279 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
1280 ;;; the next access to the instance (as defined in 88-002R) to trap
1281 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
1282 (defmethod make-instances-obsolete ((class std-class))
1283 (let* ((owrapper (class-wrapper class))
1284 (nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1286 (setf (wrapper-instance-slots-layout nwrapper)
1287 (wrapper-instance-slots-layout owrapper))
1288 (setf (wrapper-class-slots nwrapper)
1289 (wrapper-class-slots owrapper))
1291 (update-lisp-class-layout class nwrapper)
1292 (setf (slot-value class 'wrapper) nwrapper)
1293 (invalidate-wrapper owrapper :obsolete nwrapper)
1296 (defmethod make-instances-obsolete ((class symbol))
1297 (make-instances-obsolete (find-class class))
1298 ;; ANSI wants the class name when called with a symbol.
1301 ;;; OBSOLETE-INSTANCE-TRAP is the internal trap that is called when we
1302 ;;; see an obsolete instance. The times when it is called are:
1303 ;;; - when the instance is involved in method lookup
1304 ;;; - when attempting to access a slot of an instance
1306 ;;; It is not called by class-of, wrapper-of, or any of the low-level
1307 ;;; instance access macros.
1309 ;;; Of course these times when it is called are an internal
1310 ;;; implementation detail of PCL and are not part of the documented
1311 ;;; description of when the obsolete instance update happens. The
1312 ;;; documented description is as it appears in 88-002R.
1314 ;;; This has to return the new wrapper, so it counts on all the
1315 ;;; methods on obsolete-instance-trap-internal to return the new
1316 ;;; wrapper. It also does a little internal error checking to make
1317 ;;; sure that the traps are only happening when they should, and that
1318 ;;; the trap methods are computing appropriate new wrappers.
1320 ;;; OBSOLETE-INSTANCE-TRAP might be called on structure instances
1321 ;;; after a structure is redefined. In most cases,
1322 ;;; OBSOLETE-INSTANCE-TRAP will not be able to fix the old instance,
1323 ;;; so it must signal an error. The hard part of this is that the
1324 ;;; error system and debugger might cause OBSOLETE-INSTANCE-TRAP to be
1325 ;;; called again, so in that case, we have to return some reasonable
1326 ;;; wrapper, instead.
1328 (defvar *in-obsolete-instance-trap* nil)
1329 (defvar *the-wrapper-of-structure-object*
1330 (class-wrapper (find-class 'structure-object)))
1332 (define-condition obsolete-structure (error)
1333 ((datum :reader obsolete-structure-datum :initarg :datum))
1335 (lambda (condition stream)
1336 ;; Don't try to print the structure, since it probably won't work.
1338 "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
1339 (type-of (obsolete-structure-datum condition))))))
1341 (defun obsolete-instance-trap (owrapper nwrapper instance)
1342 (if (not (pcl-instance-p instance))
1343 (if *in-obsolete-instance-trap*
1344 *the-wrapper-of-structure-object*
1345 (let ((*in-obsolete-instance-trap* t))
1346 (error 'obsolete-structure :datum instance)))
1347 (let* ((class (wrapper-class* nwrapper))
1348 (copy (allocate-instance class)) ;??? allocate-instance ???
1349 (olayout (wrapper-instance-slots-layout owrapper))
1350 (nlayout (wrapper-instance-slots-layout nwrapper))
1351 (oslots (get-slots instance))
1352 (nslots (get-slots copy))
1353 (oclass-slots (wrapper-class-slots owrapper))
1358 ;; local --> local transfer value
1359 ;; local --> shared discard value, discard slot
1360 ;; local --> -- discard slot
1361 ;; shared --> local transfer value
1362 ;; shared --> shared -- (cf SHARED-INITIALIZE :AFTER STD-CLASS)
1363 ;; shared --> -- discard value
1364 ;; -- --> local add slot
1367 ;; Collect class slots from inherited wrappers. Needed for
1368 ;; shared -> local transfers of inherited slots.
1369 (let ((inherited (layout-inherits owrapper)))
1370 (loop for i from (1- (length inherited)) downto 0
1371 for layout = (aref inherited i)
1372 when (typep layout 'wrapper)
1373 do (dolist (slot (wrapper-class-slots layout))
1374 (pushnew slot oclass-slots :key #'car))))
1376 ;; Go through all the old local slots.
1378 (dolist (name olayout)
1379 (let ((npos (posq name nlayout)))
1381 (setf (clos-slots-ref nslots npos)
1382 (clos-slots-ref oslots opos))
1384 (push name discarded)
1385 (unless (eq (clos-slots-ref oslots opos) +slot-unbound+)
1386 (setf (getf plist name) (clos-slots-ref oslots opos))))))
1389 ;; Go through all the old shared slots.
1390 (dolist (oclass-slot-and-val oclass-slots)
1391 (let ((name (car oclass-slot-and-val))
1392 (val (cdr oclass-slot-and-val)))
1393 (let ((npos (posq name nlayout)))
1395 (setf (clos-slots-ref nslots npos) val)))))
1397 ;; Go through all the new local slots to compute the added slots.
1398 (dolist (nlocal nlayout)
1399 (unless (or (memq nlocal olayout)
1400 (assq nlocal oclass-slots))
1401 (push nlocal added)))
1403 (swap-wrappers-and-slots instance copy)
1405 (update-instance-for-redefined-class instance
1411 (defun change-class-internal (instance new-class initargs)
1412 (let* ((old-class (class-of instance))
1413 (copy (allocate-instance new-class))
1414 (new-wrapper (get-wrapper copy))
1415 (old-wrapper (class-wrapper old-class))
1416 (old-layout (wrapper-instance-slots-layout old-wrapper))
1417 (new-layout (wrapper-instance-slots-layout new-wrapper))
1418 (old-slots (get-slots instance))
1419 (new-slots (get-slots copy))
1420 (old-class-slots (wrapper-class-slots old-wrapper)))
1422 ;; "The values of local slots specified by both the class CTO and
1423 ;; CFROM are retained. If such a local slot was unbound, it
1424 ;; remains unbound."
1425 (let ((new-position 0))
1426 (dolist (new-slot new-layout)
1427 (let ((old-position (posq new-slot old-layout)))
1429 (setf (clos-slots-ref new-slots new-position)
1430 (clos-slots-ref old-slots old-position))))
1431 (incf new-position)))
1433 ;; "The values of slots specified as shared in the class CFROM and
1434 ;; as local in the class CTO are retained."
1435 (dolist (slot-and-val old-class-slots)
1436 (let ((position (posq (car slot-and-val) new-layout)))
1438 (setf (clos-slots-ref new-slots position) (cdr slot-and-val)))))
1440 ;; Make the copy point to the old instance's storage, and make the
1441 ;; old instance point to the new storage.
1442 (swap-wrappers-and-slots instance copy)
1444 (apply #'update-instance-for-different-class copy instance initargs)
1447 (defmethod change-class ((instance standard-object)
1448 (new-class standard-class)
1450 (change-class-internal instance new-class initargs))
1452 (defmethod change-class ((instance funcallable-standard-object)
1453 (new-class funcallable-standard-class)
1455 (change-class-internal instance new-class initargs))
1457 (defmethod change-class ((instance standard-object)
1458 (new-class funcallable-standard-class)
1460 (declare (ignore initargs))
1461 (error "You can't change the class of ~S to ~S~@
1462 because it isn't already an instance with metaclass ~S."
1463 instance new-class 'standard-class))
1465 (defmethod change-class ((instance funcallable-standard-object)
1466 (new-class standard-class)
1468 (declare (ignore initargs))
1469 (error "You can't change the class of ~S to ~S~@
1470 because it isn't already an instance with metaclass ~S."
1471 instance new-class 'funcallable-standard-class))
1473 (defmethod change-class ((instance t) (new-class-name symbol) &rest initargs)
1474 (apply #'change-class instance (find-class new-class-name) initargs))
1476 ;;;; The metaclass BUILT-IN-CLASS
1478 ;;;; This metaclass is something of a weird creature. By this point, all
1479 ;;;; instances of it which will exist have been created, and no instance
1480 ;;;; is ever created by calling MAKE-INSTANCE.
1482 ;;;; But, there are other parts of the protocol we must follow and those
1483 ;;;; definitions appear here.
1485 (defmethod shared-initialize :before
1486 ((class built-in-class) slot-names &rest initargs)
1487 (declare (ignore slot-names initargs))
1488 (error "attempt to initialize or reinitialize a built in class"))
1490 (defmethod class-direct-slots ((class built-in-class)) ())
1491 (defmethod class-slots ((class built-in-class)) ())
1492 (defmethod class-direct-default-initargs ((class built-in-class)) ())
1493 (defmethod class-default-initargs ((class built-in-class)) ())
1495 (defmethod validate-superclass ((c class) (s built-in-class))
1496 (or (eq s *the-class-t*)
1497 (eq s *the-class-stream*)))
1499 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
1500 (defmethod class-direct-slots ((class forward-referenced-class)) ())
1501 (defmethod class-direct-default-initargs ((class forward-referenced-class)) ())
1502 (macrolet ((def (method)
1503 `(defmethod ,method ((class forward-referenced-class))
1504 (error "~@<~I~S was called on a forward referenced class:~2I~_~S~:>"
1506 (def class-default-initargs)
1507 (def class-precedence-list)
1510 (defmethod validate-superclass ((c slot-class)
1511 (f forward-referenced-class))
1514 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
1515 (pushnew dependent (plist-value metaobject 'dependents)))
1517 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
1518 (setf (plist-value metaobject 'dependents)
1519 (delete dependent (plist-value metaobject 'dependents))))
1521 (defmethod map-dependents ((metaobject dependent-update-mixin) function)
1522 (dolist (dependent (plist-value metaobject 'dependents))
1523 (funcall function dependent)))