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 is not finalized.~:@>" 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 source-location)
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 source-location
304 (setf (gdefinition 'load-defclass) #'real-load-defclass)
306 (defun ensure-class (name &rest args)
307 (apply #'ensure-class-using-class
308 (let ((class (find-class name nil)))
309 (when (and class (eq name (class-name class)))
310 ;; NAME is the proper name of CLASS, so redefine it
315 (defmethod ensure-class-using-class ((class null) name &rest args &key)
316 (multiple-value-bind (meta initargs)
317 (ensure-class-values class args)
318 (set-class-type-translation (class-prototype meta) name)
319 (setf class (apply #'make-instance meta :name name initargs))
320 (without-package-locks
321 (setf (find-class name) class))
322 (set-class-type-translation class name)
325 (defmethod ensure-class-using-class ((class pcl-class) name &rest args &key)
326 (multiple-value-bind (meta initargs)
327 (ensure-class-values class args)
328 (unless (eq (class-of class) meta)
329 (apply #'change-class class meta initargs))
330 (apply #'reinitialize-instance class initargs)
331 (without-package-locks
332 (setf (find-class name) class))
333 (set-class-type-translation class name)
336 (defmethod class-predicate-name ((class t))
341 ((not (legal-class-name-p s))
342 (error "~S is not a class or a legal class name." s))
344 (or (find-class s nil)
345 (make-instance 'forward-referenced-class
348 (defun ensure-class-values (class initargs)
349 (let (metaclass metaclassp reversed-plist)
350 (doplist (key val) initargs
351 (cond ((eq key :metaclass)
355 (when (eq key :direct-superclasses)
356 (setf val (mapcar #'fix-super val)))
357 (setf reversed-plist (list* val key reversed-plist)))))
358 (values (cond (metaclassp
359 (if (classp metaclass)
361 (find-class metaclass)))
362 ((or (null class) (forward-referenced-class-p class))
363 *the-class-standard-class*)
366 (nreverse reversed-plist))))
369 (defmethod shared-initialize :after
372 &key (direct-superclasses nil direct-superclasses-p)
373 (direct-slots nil direct-slots-p)
374 (direct-default-initargs nil direct-default-initargs-p)
375 (predicate-name nil predicate-name-p))
376 (cond (direct-superclasses-p
377 (setq direct-superclasses
378 (or direct-superclasses
379 (list (if (funcallable-standard-class-p class)
380 *the-class-funcallable-standard-object*
381 *the-class-standard-object*))))
382 (dolist (superclass direct-superclasses)
383 (unless (validate-superclass class superclass)
384 (error "~@<The class ~S was specified as a ~
385 super-class of the class ~S, ~
386 but the meta-classes ~S and ~S are incompatible. ~
387 Define a method for ~S to avoid this error.~@:>"
388 superclass class (class-of superclass) (class-of class)
389 'validate-superclass)))
390 (setf (slot-value class 'direct-superclasses) direct-superclasses))
392 (setq direct-superclasses (slot-value class 'direct-superclasses))))
395 (setf (slot-value class 'direct-slots)
396 (mapcar (lambda (pl) (make-direct-slotd class pl))
398 (slot-value class 'direct-slots)))
399 (if direct-default-initargs-p
400 (setf (plist-value class 'direct-default-initargs)
401 direct-default-initargs)
402 (setq direct-default-initargs
403 (plist-value class 'direct-default-initargs)))
404 (setf (plist-value class 'class-slot-cells)
405 (let ((old-class-slot-cells (plist-value class 'class-slot-cells))
407 (dolist (dslotd direct-slots)
408 (when (eq :class (slot-definition-allocation dslotd))
410 (let* ((name (slot-definition-name dslotd))
411 (old (assoc name old-class-slot-cells)))
414 (member name slot-names))
415 (let* ((initfunction (slot-definition-initfunction dslotd))
416 (value (if initfunction
417 (funcall initfunction)
419 (push (cons name value) collect))
420 (push old collect)))))
422 (setq predicate-name (if predicate-name-p
423 (setf (slot-value class 'predicate-name)
424 (car predicate-name))
425 (or (slot-value class 'predicate-name)
426 (setf (slot-value class 'predicate-name)
427 (make-class-predicate-name (class-name
429 (add-direct-subclasses class direct-superclasses)
430 (make-class-predicate class predicate-name)
431 (update-class class nil)
432 (do* ((slots (slot-value class 'slots) (cdr slots))
434 ((null slots) (when dupes
436 ;; FIXME: the indentation request ("~4I")
437 ;; below appears not to do anything. Finding
438 ;; out why would be nice. -- CSR, 2003-04-24
439 "~@<slot names with the same SYMBOL-NAME but ~
440 different SYMBOL-PACKAGE (possible package problem) ~
441 for class ~S:~@:_~4I~<~@{~S~^~:@_~}~:>~@:>"
444 (let* ((slot (car slots))
445 (oslots (remove (slot-definition-name slot) (cdr slots)
446 :test #'string/= :key #'slot-definition-name)))
448 (pushnew (cons (slot-definition-name slot)
449 (mapcar #'slot-definition-name oslots))
451 :test #'string= :key #'car))))
452 (add-slot-accessors class direct-slots)
453 (make-preliminary-layout class))
455 (defmethod shared-initialize :after ((class forward-referenced-class)
456 slot-names &key &allow-other-keys)
457 (declare (ignore slot-names))
458 (make-preliminary-layout class))
460 (defvar *allow-forward-referenced-classes-in-cpl-p* nil)
462 ;;; Give CLASS a preliminary layout if it doesn't have one already, to
463 ;;; make it known to the type system.
464 (defun make-preliminary-layout (class)
465 (flet ((compute-preliminary-cpl (root)
466 (let ((*allow-forward-referenced-classes-in-cpl-p* t))
467 (compute-class-precedence-list root))))
468 (without-package-locks
469 (unless (class-finalized-p class)
470 (let ((name (class-name class)))
471 (setf (find-class name) class)
472 ;; KLUDGE: This is fairly horrible. We need to make a
473 ;; full-fledged CLASSOID here, not just tell the compiler that
474 ;; some class is forthcoming, because there are legitimate
475 ;; questions one can ask of the type system, implemented in
476 ;; terms of CLASSOIDs, involving forward-referenced classes. So.
477 (when (and (eq *boot-state* 'complete)
478 (null (find-classoid name nil)))
479 (setf (find-classoid name)
480 (make-standard-classoid :name name)))
481 (set-class-type-translation class name)
482 (let ((layout (make-wrapper 0 class))
483 (classoid (find-classoid name)))
484 (setf (layout-classoid layout) classoid)
485 (setf (classoid-pcl-class classoid) class)
486 (setf (slot-value class 'wrapper) layout)
487 (let ((cpl (compute-preliminary-cpl class)))
488 (setf (layout-inherits layout)
489 (order-layout-inherits
490 (map 'simple-vector #'class-wrapper
491 (reverse (rest cpl))))))
492 (register-layout layout :invalidate t)
493 (setf (classoid-layout classoid) layout)
494 (mapc #'make-preliminary-layout (class-direct-subclasses class))))))))
497 (defmethod shared-initialize :before ((class class) slot-names &key name)
498 (declare (ignore slot-names name))
499 ;; FIXME: Could this just be CLASS instead of `(CLASS ,CLASS)? If not,
500 ;; why not? (See also similar expression in !BOOTSTRAP-INITIALIZE-CLASS.)
501 (setf (slot-value class 'type) `(class ,class))
502 (setf (slot-value class 'class-eq-specializer)
503 (make-instance 'class-eq-specializer :class class)))
505 (defmethod reinitialize-instance :before ((class slot-class) &key direct-superclasses)
506 (dolist (old-super (set-difference (class-direct-superclasses class) direct-superclasses))
507 (remove-direct-subclass old-super class))
508 (remove-slot-accessors class (class-direct-slots class)))
510 (defmethod reinitialize-instance :after ((class slot-class)
513 (map-dependents class
515 (apply #'update-dependent class dependent initargs))))
517 (defmethod shared-initialize :after ((class condition-class) slot-names
518 &key direct-slots direct-superclasses)
519 (declare (ignore slot-names))
520 (let ((classoid (find-classoid (class-name class))))
521 (with-slots (wrapper class-precedence-list cpl-available-p
522 prototype predicate-name
523 (direct-supers direct-superclasses))
525 (setf (slot-value class 'direct-slots)
526 (mapcar (lambda (pl) (make-direct-slotd class pl))
528 (setf (slot-value class 'finalized-p) t)
529 (setf (classoid-pcl-class classoid) class)
530 (setq direct-supers direct-superclasses)
531 (setq wrapper (classoid-layout classoid))
532 (setq class-precedence-list (compute-class-precedence-list class))
533 (setq cpl-available-p t)
534 (add-direct-subclasses class direct-superclasses)
535 (setq predicate-name (make-class-predicate-name (class-name class)))
536 (make-class-predicate class predicate-name)
537 (setf (slot-value class 'slots) (compute-slots class))))
538 ;; Comment from Gerd's PCL, 2003-05-15:
540 ;; We don't ADD-SLOT-ACCESSORS here because we don't want to
541 ;; override condition accessors with generic functions. We do this
543 (update-pv-table-cache-info class))
545 (defmethod direct-slot-definition-class ((class condition-class)
547 (declare (ignore initargs))
548 (find-class 'condition-direct-slot-definition))
550 (defmethod effective-slot-definition-class ((class condition-class)
552 (declare (ignore initargs))
553 (find-class 'condition-effective-slot-definition))
555 (defmethod finalize-inheritance ((class condition-class))
556 (aver (slot-value class 'finalized-p))
559 (defmethod compute-effective-slot-definition
560 ((class condition-class) slot-name dslotds)
561 (let ((slotd (call-next-method)))
562 (setf (slot-definition-reader-function slotd)
564 (handler-case (condition-reader-function x slot-name)
565 ;; FIXME: FIND-SLOT-DEFAULT throws an error if the slot
566 ;; is unbound; maybe it should be a CELL-ERROR of some
568 (error () (values (slot-unbound class x slot-name))))))
569 (setf (slot-definition-writer-function slotd)
571 (condition-writer-function x v slot-name)))
572 (setf (slot-definition-boundp-function slotd)
574 (multiple-value-bind (v c)
575 (ignore-errors (condition-reader-function x slot-name))
580 (defmethod compute-slots ((class condition-class))
581 (mapcan (lambda (superclass)
582 (mapcar (lambda (dslotd)
583 (compute-effective-slot-definition
584 class (slot-definition-name dslotd) (list dslotd)))
585 (class-direct-slots superclass)))
586 (reverse (slot-value class 'class-precedence-list))))
588 (defmethod compute-slots :around ((class condition-class))
589 (let ((eslotds (call-next-method)))
590 (mapc #'initialize-internal-slot-functions eslotds)
593 (defmethod shared-initialize :after
594 ((slotd structure-slot-definition) slot-names &key
595 (allocation :instance) allocation-class)
596 (declare (ignore slot-names allocation-class))
597 (unless (eq allocation :instance)
598 (error "Structure slots must have :INSTANCE allocation.")))
600 (defun make-structure-class-defstruct-form (name direct-slots include)
601 (let* ((conc-name (format-symbol *package* "~S structure class " name))
602 (constructor (format-symbol *package* "~Aconstructor" conc-name))
603 (defstruct `(defstruct (,name
605 `((:include ,(class-name include))))
607 (:conc-name ,conc-name)
608 (:constructor ,constructor ())
610 ,@(mapcar (lambda (slot)
611 `(,(slot-definition-name slot)
614 (reader-names (mapcar (lambda (slotd)
615 (list 'slot-accessor name
616 (slot-definition-name slotd)
619 (writer-names (mapcar (lambda (slotd)
620 (list 'slot-accessor name
621 (slot-definition-name slotd)
625 (mapcar (lambda (slotd reader-name)
627 (slot-definition-defstruct-accessor-symbol
629 `(defun ,reader-name (obj)
630 (declare (type ,name obj))
632 direct-slots reader-names))
634 (mapcar (lambda (slotd writer-name)
636 (slot-definition-defstruct-accessor-symbol
638 `(defun ,writer-name (nv obj)
639 (declare (type ,name obj))
640 (setf (,accessor obj) nv))))
641 direct-slots writer-names))
645 ,@readers-init ,@writers-init
647 (values defstruct-form constructor reader-names writer-names)))
649 (defun make-defstruct-allocation-function (class)
650 (let ((dd (get-structure-dd (class-name class))))
652 (sb-kernel::%make-instance-with-layout
653 (sb-kernel::compiler-layout-or-lose (dd-name dd))))))
655 (defmethod shared-initialize :after
656 ((class structure-class)
658 &key (direct-superclasses nil direct-superclasses-p)
659 (direct-slots nil direct-slots-p)
660 direct-default-initargs
661 (predicate-name nil predicate-name-p))
662 (declare (ignore slot-names direct-default-initargs))
663 (if direct-superclasses-p
664 (setf (slot-value class 'direct-superclasses)
665 (or direct-superclasses
666 (setq direct-superclasses
667 (and (not (eq (class-name class) 'structure-object))
668 (list *the-class-structure-object*)))))
669 (setq direct-superclasses (slot-value class 'direct-superclasses)))
670 (let* ((name (class-name class))
671 (from-defclass-p (slot-value class 'from-defclass-p))
672 (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
674 (setf (slot-value class 'direct-slots)
678 (let* ((slot-name (getf pl :name))
680 (format-symbol *package*
681 "~S structure class ~A"
683 (setq pl (list* :defstruct-accessor-symbol
685 (make-direct-slotd class pl))
687 (setq direct-slots (slot-value class 'direct-slots)))
689 (let ((include (car (slot-value class 'direct-superclasses))))
690 (multiple-value-bind (defstruct-form constructor reader-names writer-names)
691 (make-structure-class-defstruct-form name direct-slots include)
692 (unless (structure-type-p name) (eval defstruct-form))
693 (mapc (lambda (dslotd reader-name writer-name)
694 (let* ((reader (gdefinition reader-name))
695 (writer (when (fboundp writer-name)
696 (gdefinition writer-name))))
697 (setf (slot-value dslotd 'internal-reader-function)
699 (setf (slot-value dslotd 'internal-writer-function)
701 direct-slots reader-names writer-names)
702 (setf (slot-value class 'defstruct-form) defstruct-form)
703 (setf (slot-value class 'defstruct-constructor) constructor)))
704 (setf (slot-value class 'defstruct-constructor)
705 (make-defstruct-allocation-function class)))
706 (add-direct-subclasses class direct-superclasses)
707 (setf (slot-value class 'class-precedence-list)
708 (compute-class-precedence-list class))
709 (setf (slot-value class 'cpl-available-p) t)
710 (setf (slot-value class 'slots) (compute-slots class))
711 (let ((lclass (find-classoid (class-name class))))
712 (setf (classoid-pcl-class lclass) class)
713 (setf (slot-value class 'wrapper) (classoid-layout lclass)))
714 (setf (slot-value class 'finalized-p) t)
715 (update-pv-table-cache-info class)
716 (setq predicate-name (if predicate-name-p
717 (setf (slot-value class 'predicate-name)
718 (car predicate-name))
719 (or (slot-value class 'predicate-name)
720 (setf (slot-value class 'predicate-name)
721 (make-class-predicate-name
722 (class-name class))))))
723 (make-class-predicate class predicate-name)
724 (add-slot-accessors class direct-slots)))
726 (defmethod direct-slot-definition-class ((class structure-class) &rest initargs)
727 (declare (ignore initargs))
728 (find-class 'structure-direct-slot-definition))
730 (defmethod finalize-inheritance ((class structure-class))
731 nil) ; always finalized
733 (defun add-slot-accessors (class dslotds)
734 (fix-slot-accessors class dslotds 'add))
736 (defun remove-slot-accessors (class dslotds)
737 (fix-slot-accessors class dslotds 'remove))
739 (defun fix-slot-accessors (class dslotds add/remove)
740 (flet ((fix (gfspec name r/w)
741 (let ((gf (cond ((eq add/remove 'add)
743 (without-package-locks
744 (ensure-generic-function gfspec))
745 (ensure-generic-function
746 gfspec :lambda-list (case r/w
748 (w '(new-value object))))))
749 ((generic-function-p (and (fboundp gfspec)
750 (fdefinition gfspec)))
751 (without-package-locks
752 (ensure-generic-function gfspec))))))
755 (r (if (eq add/remove 'add)
756 (add-reader-method class gf name)
757 (remove-reader-method class gf)))
758 (w (if (eq add/remove 'add)
759 (add-writer-method class gf name)
760 (remove-writer-method class gf))))))))
761 (dolist (dslotd dslotds)
762 (let ((slot-name (slot-definition-name dslotd)))
763 (dolist (r (slot-definition-readers dslotd))
764 (fix r slot-name 'r))
765 (dolist (w (slot-definition-writers dslotd))
766 (fix w slot-name 'w))))))
768 (defun add-direct-subclasses (class supers)
769 (dolist (super supers)
770 (unless (memq class (class-direct-subclasses class))
771 (add-direct-subclass super class))))
773 (defmethod finalize-inheritance ((class std-class))
774 (update-class class t))
776 (defmethod finalize-inheritance ((class forward-referenced-class))
777 ;; FIXME: should we not be thinking a bit about what kinds of error
778 ;; we're throwing? Maybe we need a clos-error type to mix in? Or
779 ;; possibly a forward-referenced-class-error, though that's
780 ;; difficult given e.g. class precedence list calculations...
782 "~@<FINALIZE-INHERITANCE was called on a forward referenced class:~
787 (defun class-has-a-forward-referenced-superclass-p (class)
788 (or (forward-referenced-class-p class)
789 (some #'class-has-a-forward-referenced-superclass-p
790 (class-direct-superclasses class))))
792 ;;; This is called by :after shared-initialize whenever a class is initialized
793 ;;; or reinitialized. The class may or may not be finalized.
794 (defun update-class (class finalizep)
795 ;; Comment from Gerd Moellmann:
797 ;; Note that we can't simply delay the finalization when CLASS has
798 ;; no forward referenced superclasses because that causes bootstrap
800 (without-package-locks
801 (when (and (not finalizep)
802 (not (class-finalized-p class))
803 (not (class-has-a-forward-referenced-superclass-p class)))
804 (finalize-inheritance class)
805 (return-from update-class))
806 (when (or finalizep (class-finalized-p class)
807 (not (class-has-a-forward-referenced-superclass-p class)))
808 (setf (find-class (class-name class)) class)
809 (update-cpl class (compute-class-precedence-list class))
810 ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
811 ;; class. The hoops above are to ensure that FINALIZE-INHERITANCE
812 ;; is called at finalization, so that MOP programmers can hook
813 ;; into the system as described in "Class Finalization Protocol"
814 ;; (section 5.5.2 of AMOP).
815 (update-slots class (compute-slots class))
816 (update-gfs-of-class class)
817 (update-initargs class (compute-default-initargs class))
818 (update-ctors 'finalize-inheritance :class class))
820 (dolist (sub (class-direct-subclasses class))
821 (update-class sub nil)))))
823 (define-condition cpl-protocol-violation (reference-condition error)
824 ((class :initarg :class :reader cpl-protocol-violation-class)
825 (cpl :initarg :cpl :reader cpl-protocol-violation-cpl))
826 (:default-initargs :references (list '(:sbcl :node "Metaobject Protocol")))
829 (format s "~@<Protocol violation: the ~S class ~S ~
830 ~:[has~;does not have~] the class ~S in its ~
831 class precedence list: ~S.~@:>"
832 (class-name (class-of (cpl-protocol-violation-class c)))
833 (cpl-protocol-violation-class c)
834 (eq (class-of (cpl-protocol-violation-class c))
835 *the-class-funcallable-standard-class*)
836 (find-class 'function)
837 (cpl-protocol-violation-cpl c)))))
839 (defun update-cpl (class cpl)
840 (when (eq (class-of class) *the-class-standard-class*)
841 (when (find (find-class 'function) cpl)
842 (error 'cpl-protocol-violation :class class :cpl cpl)))
843 (when (eq (class-of class) *the-class-funcallable-standard-class*)
844 (unless (find (find-class 'function) cpl)
845 (error 'cpl-protocol-violation :class class :cpl cpl)))
846 (if (class-finalized-p class)
847 (unless (and (equal (class-precedence-list class) cpl)
849 (when (position :class (class-direct-slots c)
850 :key #'slot-definition-allocation)
852 ;; comment from the old CMU CL sources:
853 ;; Need to have the cpl setup before update-lisp-class-layout
854 ;; is called on CMU CL.
855 (setf (slot-value class 'class-precedence-list) cpl)
856 (setf (slot-value class 'cpl-available-p) t)
857 (force-cache-flushes class))
859 (setf (slot-value class 'class-precedence-list) cpl)
860 (setf (slot-value class 'cpl-available-p) t)))
861 (update-class-can-precede-p cpl))
863 (defun update-class-can-precede-p (cpl)
865 (let ((first (car cpl)))
866 (dolist (c (cdr cpl))
867 (pushnew c (slot-value first 'can-precede-list))))
868 (update-class-can-precede-p (cdr cpl))))
870 (defun class-can-precede-p (class1 class2)
871 (member class2 (class-can-precede-list class1)))
873 (defun update-slots (class eslotds)
874 (let ((instance-slots ())
876 (dolist (eslotd eslotds)
877 (let ((alloc (slot-definition-allocation eslotd)))
879 (:instance (push eslotd instance-slots))
880 (:class (push eslotd class-slots)))))
882 ;; If there is a change in the shape of the instances then the
883 ;; old class is now obsolete.
884 (let* ((nlayout (mapcar #'slot-definition-name
885 (sort instance-slots #'<
886 :key #'slot-definition-location)))
887 (nslots (length nlayout))
888 (nwrapper-class-slots (compute-class-slots class-slots))
889 (owrapper (when (class-finalized-p class)
890 (class-wrapper class)))
891 (olayout (when owrapper
892 (wrapper-instance-slots-layout owrapper)))
893 (owrapper-class-slots (and owrapper (wrapper-class-slots owrapper)))
895 (cond ((null owrapper)
896 (make-wrapper nslots class))
897 ((and (equal nlayout olayout)
899 (loop for o in owrapper-class-slots
900 for n in nwrapper-class-slots
901 do (unless (eq (car o) (car n)) (return t)))))
904 ;; This will initialize the new wrapper to have the
905 ;; same state as the old wrapper. We will then have
906 ;; to change that. This may seem like wasted work
907 ;; (and it is), but the spec requires that we call
908 ;; MAKE-INSTANCES-OBSOLETE.
909 (make-instances-obsolete class)
910 (class-wrapper class)))))
912 (with-slots (wrapper slots) class
913 (update-lisp-class-layout class nwrapper)
915 (wrapper-instance-slots-layout nwrapper) nlayout
916 (wrapper-class-slots nwrapper) nwrapper-class-slots
917 (wrapper-no-of-instance-slots nwrapper) nslots
919 (setf (slot-value class 'finalized-p) t)
920 (unless (eq owrapper nwrapper)
921 (update-pv-table-cache-info class)
922 (maybe-update-standard-class-locations class)))))
924 (defun compute-class-slots (eslotds)
926 (dolist (eslotd eslotds)
927 (push (assoc (slot-definition-name eslotd)
928 (class-slot-cells (slot-definition-class eslotd)))
932 (defun update-gfs-of-class (class)
933 (when (and (class-finalized-p class)
934 (let ((cpl (class-precedence-list class)))
935 (or (member *the-class-slot-class* cpl)
936 (member *the-class-standard-effective-slot-definition*
938 (let ((gf-table (make-hash-table :test 'eq)))
939 (labels ((collect-gfs (class)
940 (dolist (gf (specializer-direct-generic-functions class))
941 (setf (gethash gf gf-table) t))
942 (mapc #'collect-gfs (class-direct-superclasses class))))
944 (maphash (lambda (gf ignore)
945 (declare (ignore ignore))
946 (update-gf-dfun class gf))
949 (defun update-initargs (class inits)
950 (setf (plist-value class 'default-initargs) inits))
952 (defmethod compute-default-initargs ((class slot-class))
953 (let ((initargs (loop for c in (class-precedence-list class)
954 append (class-direct-default-initargs c))))
955 (delete-duplicates initargs :test #'eq :key #'car :from-end t)))
957 ;;;; protocols for constructing direct and effective slot definitions
959 (defmethod direct-slot-definition-class ((class std-class) &rest initargs)
960 (declare (ignore initargs))
961 (find-class 'standard-direct-slot-definition))
963 (defun make-direct-slotd (class initargs)
964 (apply #'make-instance
965 (apply #'direct-slot-definition-class class initargs)
969 ;;; I (CSR) am not sure, but I believe that the particular order of
970 ;;; slots is quite important: it is ideal to attempt to have a
971 ;;; constant slot location for the same notional slots as much as
972 ;;; possible, so that clever discriminating functions (ONE-INDEX et
973 ;;; al.) have a chance of working. The below at least walks through
974 ;;; the slots predictably, but maybe it would be good to compute some
975 ;;; kind of optimal slot layout by looking at locations of slots in
977 (defun std-compute-slots (class)
978 ;; As specified, we must call COMPUTE-EFFECTIVE-SLOT-DEFINITION once
979 ;; for each different slot name we find in our superclasses. Each
980 ;; call receives the class and a list of the dslotds with that name.
981 ;; The list is in most-specific-first order.
982 (let ((name-dslotds-alist ()))
983 (dolist (c (reverse (class-precedence-list class)))
984 (dolist (slot (class-direct-slots c))
985 (let* ((name (slot-definition-name slot))
986 (entry (assq name name-dslotds-alist)))
988 (push slot (cdr entry))
989 (push (list name slot) name-dslotds-alist)))))
990 (mapcar (lambda (direct)
991 (compute-effective-slot-definition class
994 (nreverse name-dslotds-alist))))
996 (defmethod compute-slots ((class standard-class))
997 (std-compute-slots class))
998 (defmethod compute-slots ((class funcallable-standard-class))
999 (std-compute-slots class))
1001 (defun std-compute-slots-around (class eslotds)
1002 (let ((location -1))
1003 (dolist (eslotd eslotds eslotds)
1004 (setf (slot-definition-location eslotd)
1005 (case (slot-definition-allocation eslotd)
1009 (let* ((name (slot-definition-name eslotd))
1012 (slot-definition-allocation-class eslotd)
1013 ;; we get here if the user adds an extra slot
1015 (setf (slot-definition-allocation-class eslotd)
1017 ;; which raises the question of what we should
1018 ;; do if we find that said user has added a slot
1019 ;; with the same name as another slot...
1020 (cell (or (assq name (class-slot-cells from-class))
1021 (setf (class-slot-cells from-class)
1022 (cons (cons name +slot-unbound+)
1023 (class-slot-cells from-class))))))
1025 (if (eq +slot-unbound+ (cdr cell))
1026 ;; We may have inherited an initfunction
1027 (let ((initfun (slot-definition-initfunction eslotd)))
1029 (rplacd cell (funcall initfun))
1032 (unless (slot-definition-class eslotd)
1033 (setf (slot-definition-class eslotd) class))
1034 (initialize-internal-slot-functions eslotd))))
1036 (defmethod compute-slots :around ((class standard-class))
1037 (let ((eslotds (call-next-method)))
1038 (std-compute-slots-around class eslotds)))
1039 (defmethod compute-slots :around ((class funcallable-standard-class))
1040 (let ((eslotds (call-next-method)))
1041 (std-compute-slots-around class eslotds)))
1043 (defmethod compute-slots ((class structure-class))
1044 (mapcan (lambda (superclass)
1045 (mapcar (lambda (dslotd)
1046 (compute-effective-slot-definition
1048 (slot-definition-name dslotd)
1050 (class-direct-slots superclass)))
1051 (reverse (slot-value class 'class-precedence-list))))
1053 (defmethod compute-slots :around ((class structure-class))
1054 (let ((eslotds (call-next-method)))
1055 (mapc #'initialize-internal-slot-functions eslotds)
1058 (defmethod compute-effective-slot-definition ((class slot-class) name dslotds)
1059 (declare (ignore name))
1060 (let* ((initargs (compute-effective-slot-definition-initargs class dslotds))
1061 (class (apply #'effective-slot-definition-class class initargs)))
1062 (apply #'make-instance class initargs)))
1064 (defmethod effective-slot-definition-class ((class std-class) &rest initargs)
1065 (declare (ignore initargs))
1066 (find-class 'standard-effective-slot-definition))
1068 (defmethod effective-slot-definition-class ((class structure-class) &rest initargs)
1069 (declare (ignore initargs))
1070 (find-class 'structure-effective-slot-definition))
1072 (defmethod compute-effective-slot-definition-initargs
1073 ((class slot-class) direct-slotds)
1079 (allocation-class nil)
1082 (documentationp nil)
1087 (dolist (slotd direct-slotds)
1090 (setq name (slot-definition-name slotd)
1093 (when (slot-definition-initfunction slotd)
1094 (setq initform (slot-definition-initform slotd)
1095 initfunction (slot-definition-initfunction slotd)
1097 (unless documentationp
1098 (when (%slot-definition-documentation slotd)
1099 (setq documentation (%slot-definition-documentation slotd)
1102 (setq allocation (slot-definition-allocation slotd)
1103 allocation-class (slot-definition-class slotd)
1105 (setq initargs (append (slot-definition-initargs slotd) initargs))
1106 (let ((slotd-type (slot-definition-type slotd)))
1107 (setq type (cond ((eq type t) slotd-type)
1108 ((*subtypep type slotd-type) type)
1109 (t `(and ,type ,slotd-type)))))))
1112 :initfunction initfunction
1114 :allocation allocation
1115 :allocation-class allocation-class
1118 :documentation documentation)))
1120 (defmethod compute-effective-slot-definition-initargs :around
1121 ((class structure-class) direct-slotds)
1122 (let ((slotd (car direct-slotds)))
1123 (list* :defstruct-accessor-symbol
1124 (slot-definition-defstruct-accessor-symbol slotd)
1125 :internal-reader-function
1126 (slot-definition-internal-reader-function slotd)
1127 :internal-writer-function
1128 (slot-definition-internal-writer-function slotd)
1129 (call-next-method))))
1131 ;;; NOTE: For bootstrapping considerations, these can't use MAKE-INSTANCE
1132 ;;; to make the method object. They have to use make-a-method which
1133 ;;; is a specially bootstrapped mechanism for making standard methods.
1134 (defmethod reader-method-class ((class slot-class) direct-slot &rest initargs)
1135 (declare (ignore direct-slot initargs))
1136 (find-class 'standard-reader-method))
1138 (defmethod add-reader-method ((class slot-class) generic-function slot-name)
1139 (add-method generic-function
1140 (make-a-method 'standard-reader-method
1142 (list (or (class-name class) 'object))
1144 (make-reader-method-function class slot-name)
1145 "automatically generated reader method"
1148 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
1149 (declare (ignore direct-slot initargs))
1150 (find-class 'standard-writer-method))
1152 (defmethod add-writer-method ((class slot-class) generic-function slot-name)
1153 (add-method generic-function
1154 (make-a-method 'standard-writer-method
1156 (list 'new-value (or (class-name class) 'object))
1157 (list *the-class-t* class)
1158 (make-writer-method-function class slot-name)
1159 "automatically generated writer method"
1162 (defmethod add-boundp-method ((class slot-class) generic-function slot-name)
1163 (add-method generic-function
1164 (make-a-method 'standard-boundp-method
1166 (list (or (class-name class) 'object))
1168 (make-boundp-method-function class slot-name)
1169 "automatically generated boundp method"
1172 (defmethod remove-reader-method ((class slot-class) generic-function)
1173 (let ((method (get-method generic-function () (list class) nil)))
1174 (when method (remove-method generic-function method))))
1176 (defmethod remove-writer-method ((class slot-class) generic-function)
1178 (get-method generic-function () (list *the-class-t* class) nil)))
1179 (when method (remove-method generic-function method))))
1181 (defmethod remove-boundp-method ((class slot-class) generic-function)
1182 (let ((method (get-method generic-function () (list class) nil)))
1183 (when method (remove-method generic-function method))))
1185 ;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITE-METHOD function are NOT
1186 ;;; part of the standard protocol. They are however useful, PCL makes
1187 ;;; use of them internally and documents them for PCL users.
1189 ;;; *** This needs work to make type testing by the writer functions which
1190 ;;; *** do type testing faster. The idea would be to have one constructor
1191 ;;; *** for each possible type test.
1193 ;;; *** There is a subtle bug here which is going to have to be fixed.
1194 ;;; *** Namely, the simplistic use of the template has to be fixed. We
1195 ;;; *** have to give the OPTIMIZE-SLOT-VALUE method the user might have
1196 ;;; *** defined for this metaclass a chance to run.
1198 (defmethod make-reader-method-function ((class slot-class) slot-name)
1199 (make-std-reader-method-function (class-name class) slot-name))
1201 (defmethod make-writer-method-function ((class slot-class) slot-name)
1202 (make-std-writer-method-function (class-name class) slot-name))
1204 (defmethod make-boundp-method-function ((class slot-class) slot-name)
1205 (make-std-boundp-method-function (class-name class) slot-name))
1207 (defmethod compatible-meta-class-change-p (class proto-new-class)
1208 (eq (class-of class) (class-of proto-new-class)))
1210 (defmethod validate-superclass ((class class) (superclass class))
1211 (or (eq superclass *the-class-t*)
1212 (eq (class-of class) (class-of superclass))
1213 (and (eq (class-of superclass) *the-class-standard-class*)
1214 (eq (class-of class) *the-class-funcallable-standard-class*))
1215 (and (eq (class-of superclass) *the-class-funcallable-standard-class*)
1216 (eq (class-of class) *the-class-standard-class*))))
1218 ;;; What this does depends on which of the four possible values of
1219 ;;; LAYOUT-INVALID the PCL wrapper has; the simplest case is when it
1220 ;;; is (:FLUSH <wrapper>) or (:OBSOLETE <wrapper>), when there is
1221 ;;; nothing to do, as the new wrapper has already been created. If
1222 ;;; LAYOUT-INVALID returns NIL, then we invalidate it (setting it to
1223 ;;; (:FLUSH <wrapper>); UPDATE-SLOTS later gets to choose whether or
1224 ;;; not to "upgrade" this to (:OBSOLETE <wrapper>).
1226 ;;; This leaves the case where LAYOUT-INVALID returns T, which happens
1227 ;;; when REGISTER-LAYOUT has invalidated a superclass of CLASS (which
1228 ;;; invalidated all the subclasses in SB-KERNEL land). Again, here we
1229 ;;; must flush the caches and allow UPDATE-SLOTS to decide whether to
1230 ;;; obsolete the wrapper.
1232 ;;; FIXME: either here or in INVALID-WRAPPER-P looks like a good place
1233 ;;; for (AVER (NOT (EQ (LAYOUT-INVALID OWRAPPER)
1234 ;;; :UNINITIALIZED)))
1236 ;;; Thanks to Gerd Moellmann for the explanation. -- CSR, 2002-10-29
1237 (defun force-cache-flushes (class)
1238 (let* ((owrapper (class-wrapper class)))
1239 ;; We only need to do something if the wrapper is still valid. If
1240 ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
1241 ;; both of those will already be doing what we want. In
1242 ;; particular, we must be sure we never change an OBSOLETE into a
1243 ;; FLUSH since OBSOLETE means do what FLUSH does and then some.
1244 (when (or (not (invalid-wrapper-p owrapper))
1245 ;; KLUDGE: despite the observations above, this remains
1246 ;; a violation of locality or what might be considered
1247 ;; good style. There has to be a better way! -- CSR,
1249 (eq (layout-invalid owrapper) t))
1250 (let ((nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1252 (setf (wrapper-instance-slots-layout nwrapper)
1253 (wrapper-instance-slots-layout owrapper))
1254 (setf (wrapper-class-slots nwrapper)
1255 (wrapper-class-slots owrapper))
1257 (update-lisp-class-layout class nwrapper)
1258 (setf (slot-value class 'wrapper) nwrapper)
1259 ;; Use :OBSOLETE instead of :FLUSH if any superclass has
1261 (if (find-if (lambda (x)
1262 (and (consp x) (eq :obsolete (car x))))
1263 (layout-inherits owrapper)
1264 :key #'layout-invalid)
1265 (invalidate-wrapper owrapper :obsolete nwrapper)
1266 (invalidate-wrapper owrapper :flush nwrapper)))))))
1268 (defun flush-cache-trap (owrapper nwrapper instance)
1269 (declare (ignore owrapper))
1270 (set-wrapper instance nwrapper))
1272 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
1273 ;;; the next access to the instance (as defined in 88-002R) to trap
1274 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
1275 (defmethod make-instances-obsolete ((class std-class))
1276 (let* ((owrapper (class-wrapper class))
1277 (nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1279 (setf (wrapper-instance-slots-layout nwrapper)
1280 (wrapper-instance-slots-layout owrapper))
1281 (setf (wrapper-class-slots nwrapper)
1282 (wrapper-class-slots owrapper))
1284 (update-lisp-class-layout class nwrapper)
1285 (setf (slot-value class 'wrapper) nwrapper)
1286 (invalidate-wrapper owrapper :obsolete nwrapper)
1289 (defmethod make-instances-obsolete ((class symbol))
1290 (make-instances-obsolete (find-class class))
1291 ;; ANSI wants the class name when called with a symbol.
1294 ;;; OBSOLETE-INSTANCE-TRAP is the internal trap that is called when we
1295 ;;; see an obsolete instance. The times when it is called are:
1296 ;;; - when the instance is involved in method lookup
1297 ;;; - when attempting to access a slot of an instance
1299 ;;; It is not called by class-of, wrapper-of, or any of the low-level
1300 ;;; instance access macros.
1302 ;;; Of course these times when it is called are an internal
1303 ;;; implementation detail of PCL and are not part of the documented
1304 ;;; description of when the obsolete instance update happens. The
1305 ;;; documented description is as it appears in 88-002R.
1307 ;;; This has to return the new wrapper, so it counts on all the
1308 ;;; methods on obsolete-instance-trap-internal to return the new
1309 ;;; wrapper. It also does a little internal error checking to make
1310 ;;; sure that the traps are only happening when they should, and that
1311 ;;; the trap methods are computing appropriate new wrappers.
1313 ;;; OBSOLETE-INSTANCE-TRAP might be called on structure instances
1314 ;;; after a structure is redefined. In most cases,
1315 ;;; OBSOLETE-INSTANCE-TRAP will not be able to fix the old instance,
1316 ;;; so it must signal an error. The hard part of this is that the
1317 ;;; error system and debugger might cause OBSOLETE-INSTANCE-TRAP to be
1318 ;;; called again, so in that case, we have to return some reasonable
1319 ;;; wrapper, instead.
1321 (defvar *in-obsolete-instance-trap* nil)
1322 (defvar *the-wrapper-of-structure-object*
1323 (class-wrapper (find-class 'structure-object)))
1325 (define-condition obsolete-structure (error)
1326 ((datum :reader obsolete-structure-datum :initarg :datum))
1328 (lambda (condition stream)
1329 ;; Don't try to print the structure, since it probably won't work.
1331 "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
1332 (type-of (obsolete-structure-datum condition))))))
1334 (defun obsolete-instance-trap (owrapper nwrapper instance)
1335 (if (not (pcl-instance-p instance))
1336 (if *in-obsolete-instance-trap*
1337 *the-wrapper-of-structure-object*
1338 (let ((*in-obsolete-instance-trap* t))
1339 (error 'obsolete-structure :datum instance)))
1340 (let* ((class (wrapper-class* nwrapper))
1341 (copy (allocate-instance class)) ;??? allocate-instance ???
1342 (olayout (wrapper-instance-slots-layout owrapper))
1343 (nlayout (wrapper-instance-slots-layout nwrapper))
1344 (oslots (get-slots instance))
1345 (nslots (get-slots copy))
1346 (oclass-slots (wrapper-class-slots owrapper))
1351 ;; local --> local transfer value
1352 ;; local --> shared discard value, discard slot
1353 ;; local --> -- discard slot
1354 ;; shared --> local transfer value
1355 ;; shared --> shared -- (cf SHARED-INITIALIZE :AFTER STD-CLASS)
1356 ;; shared --> -- discard value
1357 ;; -- --> local add slot
1360 ;; Collect class slots from inherited wrappers. Needed for
1361 ;; shared -> local transfers of inherited slots.
1362 (let ((inherited (layout-inherits owrapper)))
1363 (loop for i from (1- (length inherited)) downto 0
1364 for layout = (aref inherited i)
1365 when (typep layout 'wrapper)
1366 do (dolist (slot (wrapper-class-slots layout))
1367 (pushnew slot oclass-slots :key #'car))))
1369 ;; Go through all the old local slots.
1371 (dolist (name olayout)
1372 (let ((npos (posq name nlayout)))
1374 (setf (clos-slots-ref nslots npos)
1375 (clos-slots-ref oslots opos))
1377 (push name discarded)
1378 (unless (eq (clos-slots-ref oslots opos) +slot-unbound+)
1379 (setf (getf plist name) (clos-slots-ref oslots opos))))))
1382 ;; Go through all the old shared slots.
1383 (dolist (oclass-slot-and-val oclass-slots)
1384 (let ((name (car oclass-slot-and-val))
1385 (val (cdr oclass-slot-and-val)))
1386 (let ((npos (posq name nlayout)))
1388 (setf (clos-slots-ref nslots npos) val)))))
1390 ;; Go through all the new local slots to compute the added slots.
1391 (dolist (nlocal nlayout)
1392 (unless (or (memq nlocal olayout)
1393 (assq nlocal oclass-slots))
1394 (push nlocal added)))
1396 (swap-wrappers-and-slots instance copy)
1398 (update-instance-for-redefined-class instance
1404 (defun change-class-internal (instance new-class initargs)
1405 (let* ((old-class (class-of instance))
1406 (copy (allocate-instance new-class))
1407 (new-wrapper (get-wrapper copy))
1408 (old-wrapper (class-wrapper old-class))
1409 (old-layout (wrapper-instance-slots-layout old-wrapper))
1410 (new-layout (wrapper-instance-slots-layout new-wrapper))
1411 (old-slots (get-slots instance))
1412 (new-slots (get-slots copy))
1413 (old-class-slots (wrapper-class-slots old-wrapper)))
1415 ;; "The values of local slots specified by both the class CTO and
1416 ;; CFROM are retained. If such a local slot was unbound, it
1417 ;; remains unbound."
1418 (let ((new-position 0))
1419 (dolist (new-slot new-layout)
1420 (let ((old-position (posq new-slot old-layout)))
1422 (setf (clos-slots-ref new-slots new-position)
1423 (clos-slots-ref old-slots old-position))))
1424 (incf new-position)))
1426 ;; "The values of slots specified as shared in the class CFROM and
1427 ;; as local in the class CTO are retained."
1428 (dolist (slot-and-val old-class-slots)
1429 (let ((position (posq (car slot-and-val) new-layout)))
1431 (setf (clos-slots-ref new-slots position) (cdr slot-and-val)))))
1433 ;; Make the copy point to the old instance's storage, and make the
1434 ;; old instance point to the new storage.
1435 (swap-wrappers-and-slots instance copy)
1437 (apply #'update-instance-for-different-class copy instance initargs)
1440 (defmethod change-class ((instance standard-object)
1441 (new-class standard-class)
1443 (change-class-internal instance new-class initargs))
1445 (defmethod change-class ((instance funcallable-standard-object)
1446 (new-class funcallable-standard-class)
1448 (change-class-internal instance new-class initargs))
1450 (defmethod change-class ((instance standard-object)
1451 (new-class funcallable-standard-class)
1453 (declare (ignore initargs))
1454 (error "You can't change the class of ~S to ~S~@
1455 because it isn't already an instance with metaclass ~S."
1456 instance new-class 'standard-class))
1458 (defmethod change-class ((instance funcallable-standard-object)
1459 (new-class standard-class)
1461 (declare (ignore initargs))
1462 (error "You can't change the class of ~S to ~S~@
1463 because it isn't already an instance with metaclass ~S."
1464 instance new-class 'funcallable-standard-class))
1466 (defmethod change-class ((instance t) (new-class-name symbol) &rest initargs)
1467 (apply #'change-class instance (find-class new-class-name) initargs))
1469 ;;;; The metaclass BUILT-IN-CLASS
1471 ;;;; This metaclass is something of a weird creature. By this point, all
1472 ;;;; instances of it which will exist have been created, and no instance
1473 ;;;; is ever created by calling MAKE-INSTANCE.
1475 ;;;; But, there are other parts of the protocol we must follow and those
1476 ;;;; definitions appear here.
1478 (defmethod shared-initialize :before
1479 ((class built-in-class) slot-names &rest initargs)
1480 (declare (ignore slot-names initargs))
1481 (error "attempt to initialize or reinitialize a built in class"))
1483 (defmethod class-direct-slots ((class built-in-class)) ())
1484 (defmethod class-slots ((class built-in-class)) ())
1485 (defmethod class-direct-default-initargs ((class built-in-class)) ())
1486 (defmethod class-default-initargs ((class built-in-class)) ())
1488 (defmethod validate-superclass ((c class) (s built-in-class))
1489 (or (eq s *the-class-t*) (eq s *the-class-stream*)
1490 ;; FIXME: bad things happen if someone tries to mix in both
1491 ;; FILE-STREAM and STRING-STREAM (as they have the same
1492 ;; layout-depthoid). Is there any way we can provide a useful
1493 ;; error message? -- CSR, 2005-05-03
1494 (eq s *the-class-file-stream*) (eq s *the-class-string-stream*)))
1496 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
1497 (defmethod class-direct-slots ((class forward-referenced-class)) ())
1498 (defmethod class-direct-default-initargs ((class forward-referenced-class)) ())
1499 (macrolet ((def (method)
1500 `(defmethod ,method ((class forward-referenced-class))
1501 (error "~@<~I~S was called on a forward referenced class:~2I~_~S~:>"
1503 (def class-default-initargs)
1504 (def class-precedence-list)
1507 (defmethod validate-superclass ((c slot-class)
1508 (f forward-referenced-class))
1511 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
1512 (pushnew dependent (plist-value metaobject 'dependents)))
1514 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
1515 (setf (plist-value metaobject 'dependents)
1516 (delete dependent (plist-value metaobject 'dependents))))
1518 (defmethod map-dependents ((metaobject dependent-update-mixin) function)
1519 (dolist (dependent (plist-value metaobject 'dependents))
1520 (funcall function dependent)))