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 ((class std-class))
125 (with-slots (prototype) class
126 (or prototype (setq prototype (allocate-instance class)))))
128 (defmethod class-prototype ((class structure-class))
129 (with-slots (prototype wrapper defstruct-constructor) class
132 (if defstruct-constructor
133 (allocate-instance class)
134 (allocate-standard-instance wrapper))))))
136 (defmethod class-prototype ((class condition-class))
137 (with-slots (prototype) class
138 (or prototype (setf prototype (allocate-instance 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))))))
294 (defun real-load-defclass (name metaclass-name supers slots other)
295 (let ((res (apply #'ensure-class name :metaclass metaclass-name
296 :direct-superclasses supers
298 :definition-source `((defclass ,name)
303 (setf (gdefinition 'load-defclass) #'real-load-defclass)
305 (defun ensure-class (name &rest args)
306 (apply #'ensure-class-using-class
307 (let ((class (find-class name nil)))
308 (when (and class (eq name (class-name class)))
309 ;; NAME is the proper name of CLASS, so redefine it
314 (defmethod ensure-class-using-class ((class null) name &rest args &key)
315 (without-package-locks
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 (find-class name) class)
321 (set-class-type-translation class name)
324 (defmethod ensure-class-using-class ((class pcl-class) name &rest args &key)
325 (without-package-locks
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 (setf (find-class name) class)
332 (set-class-type-translation class name)
335 (defmethod class-predicate-name ((class t))
340 ((not (legal-class-name-p s))
341 (error "~S is not a class or a legal class name." s))
343 (or (find-class s nil)
344 (make-instance 'forward-referenced-class
347 (defun ensure-class-values (class args)
348 (let* ((initargs (copy-list args))
349 (unsupplied (list 1))
350 (supplied-meta (getf initargs :metaclass unsupplied))
351 (supplied-supers (getf initargs :direct-superclasses unsupplied))
352 (supplied-slots (getf initargs :direct-slots unsupplied))
354 (cond ((neq supplied-meta unsupplied)
355 (find-class supplied-meta))
357 (forward-referenced-class-p class))
358 *the-class-standard-class*)
361 ;; KLUDGE: It seemed to me initially that there ought to be a way
362 ;; of collecting all the erroneous problems in one go, rather than
363 ;; this way of solving the problem of signalling the errors that
364 ;; we are required to, which stops at the first bogus input.
365 ;; However, after playing around a little, I couldn't find that
366 ;; way, so I've left it as is, but if someone does come up with a
367 ;; better way... -- CSR, 2002-09-08
368 (do ((direct-slots (getf initargs :direct-slots) (cdr direct-slots)))
369 ((endp direct-slots) nil)
370 (destructuring-bind (slot &rest more) direct-slots
371 (let ((slot-name (getf slot :name)))
372 (when (some (lambda (s) (eq slot-name (getf s :name))) more)
373 ;; FIXME: It's quite possible that we ought to define an
374 ;; SB-INT:PROGRAM-ERROR function to signal these and other
375 ;; errors throughout the codebase that are required to be
376 ;; of type PROGRAM-ERROR.
377 (error 'simple-program-error
378 :format-control "~@<There is more than one direct slot ~
380 :format-arguments (list slot-name)))
381 (do ((stuff slot (cddr stuff)))
383 (destructuring-bind (option value &rest more) stuff
385 ((and (member option '(:allocation :type
386 :initform :documentation))
388 (getf more option unsupplied))))
389 (error 'simple-program-error
390 :format-control "~@<Duplicate slot option ~S for ~
392 :format-arguments (list option slot-name)))
393 ((and (eq option :readers)
394 (notevery #'symbolp value))
395 (error 'simple-program-error
396 :format-control "~@<Slot reader names for slot ~
397 named ~S must be symbols.~:>"
398 :format-arguments (list slot-name)))
399 ((and (eq option :initargs)
400 (notevery #'symbolp value))
401 (error 'simple-program-error
402 :format-control "~@<Slot initarg names for slot ~
403 named ~S must be symbols.~:>"
404 :format-arguments (list slot-name)))))))))
405 (loop for (initarg . more) on (getf initargs :direct-default-initargs)
406 for name = (car initarg)
407 when (some (lambda (a) (eq (car a) name)) more)
408 do (error 'simple-program-error
409 :format-control "~@<Duplicate initialization argument ~
410 name ~S in :DEFAULT-INITARGS.~:>"
411 :format-arguments (list name class)))
413 (default-initargs 0))
414 (do ((args initargs (cddr args)))
418 (when (> (incf metaclass) 1)
419 (error 'simple-program-error
420 :format-control "~@<More than one :METACLASS ~
421 option specified.~:>")))
422 (:direct-default-initargs
423 (when (> (incf default-initargs) 1)
424 (error 'simple-program-error
425 :format-control "~@<More than one :DEFAULT-INITARGS ~
426 option specified.~:>"))))))
427 (remf initargs :metaclass)
428 (loop (unless (remf initargs :direct-superclasses) (return)))
429 (loop (unless (remf initargs :direct-slots) (return)))
433 (when (neq supplied-supers unsupplied)
434 (list :direct-superclasses (mapcar #'fix-super supplied-supers)))
435 (when (neq supplied-slots unsupplied)
436 (list :direct-slots supplied-slots))
439 (defmethod shared-initialize :after
442 &key (direct-superclasses nil direct-superclasses-p)
443 (direct-slots nil direct-slots-p)
444 (direct-default-initargs nil direct-default-initargs-p)
445 (predicate-name nil predicate-name-p))
446 (cond (direct-superclasses-p
447 (setq direct-superclasses
448 (or direct-superclasses
449 (list (if (funcallable-standard-class-p class)
450 *the-class-funcallable-standard-object*
451 *the-class-standard-object*))))
452 (dolist (superclass direct-superclasses)
453 (unless (validate-superclass class superclass)
454 (error "The class ~S was specified as a~%
455 super-class of the class ~S;~%~
456 but the meta-classes ~S and~%~S are incompatible.~@
457 Define a method for ~S to avoid this error."
458 superclass class (class-of superclass) (class-of class)
459 'validate-superclass)))
460 (setf (slot-value class 'direct-superclasses) direct-superclasses))
462 (setq direct-superclasses (slot-value class 'direct-superclasses))))
465 (setf (slot-value class 'direct-slots)
466 (mapcar (lambda (pl) (make-direct-slotd class pl))
468 (slot-value class 'direct-slots)))
469 (if direct-default-initargs-p
470 (setf (plist-value class 'direct-default-initargs)
471 direct-default-initargs)
472 (setq direct-default-initargs
473 (plist-value class 'direct-default-initargs)))
474 (setf (plist-value class 'class-slot-cells)
475 (let ((old-class-slot-cells (plist-value class 'class-slot-cells))
477 (dolist (dslotd direct-slots)
478 (when (eq :class (slot-definition-allocation dslotd))
480 (let* ((name (slot-definition-name dslotd))
481 (old (assoc name old-class-slot-cells)))
484 (member name slot-names))
485 (let* ((initfunction (slot-definition-initfunction dslotd))
486 (value (if initfunction
487 (funcall initfunction)
489 (push (cons name value) collect))
490 (push old collect)))))
492 (setq predicate-name (if predicate-name-p
493 (setf (slot-value class 'predicate-name)
494 (car predicate-name))
495 (or (slot-value class 'predicate-name)
496 (setf (slot-value class 'predicate-name)
497 (make-class-predicate-name (class-name
499 (add-direct-subclasses class direct-superclasses)
500 (make-class-predicate class predicate-name)
501 (update-class class nil)
502 (do* ((slots (slot-value class 'slots) (cdr slots))
504 ((null slots) (when dupes
506 ;; FIXME: the indentation request ("~4I")
507 ;; below appears not to do anything. Finding
508 ;; out why would be nice. -- CSR, 2003-04-24
509 "~@<slot names with the same SYMBOL-NAME but ~
510 different SYMBOL-PACKAGE (possible package problem) ~
511 for class ~S:~@:_~4I~<~@{~S~^~:@_~}~:>~@:>"
514 (let* ((slot (car slots))
515 (oslots (remove (slot-definition-name slot) (cdr slots)
516 :test #'string/= :key #'slot-definition-name)))
518 (pushnew (cons (slot-definition-name slot)
519 (mapcar #'slot-definition-name oslots))
521 :test #'string= :key #'car))))
522 (add-slot-accessors class direct-slots)
523 (make-preliminary-layout class))
525 (defmethod shared-initialize :after ((class forward-referenced-class)
526 slot-names &key &allow-other-keys)
527 (declare (ignore slot-names))
528 (make-preliminary-layout class))
530 (defvar *allow-forward-referenced-classes-in-cpl-p* nil)
532 ;;; Give CLASS a preliminary layout if it doesn't have one already, to
533 ;;; make it known to the type system.
534 (defun make-preliminary-layout (class)
535 (flet ((compute-preliminary-cpl (root)
536 (let ((*allow-forward-referenced-classes-in-cpl-p* t))
537 (compute-class-precedence-list root))))
538 (without-package-locks
539 (unless (class-finalized-p class)
540 (let ((name (class-name class)))
541 (setf (find-class name) class)
542 ;; KLUDGE: This is fairly horrible. We need to make a
543 ;; full-fledged CLASSOID here, not just tell the compiler that
544 ;; some class is forthcoming, because there are legitimate
545 ;; questions one can ask of the type system, implemented in
546 ;; terms of CLASSOIDs, involving forward-referenced classes. So.
547 (when (and (eq *boot-state* 'complete)
548 (null (find-classoid name nil)))
549 (setf (find-classoid name)
550 (make-standard-classoid :name name)))
551 (set-class-type-translation class name)
552 (let ((layout (make-wrapper 0 class))
553 (classoid (find-classoid name)))
554 (setf (layout-classoid layout) classoid)
555 (setf (classoid-pcl-class classoid) class)
556 (setf (slot-value class 'wrapper) layout)
557 (let ((cpl (compute-preliminary-cpl class)))
558 (setf (layout-inherits layout)
559 (order-layout-inherits
560 (map 'simple-vector #'class-wrapper
561 (reverse (rest cpl))))))
562 (register-layout layout :invalidate t)
563 (setf (classoid-layout classoid) layout)
564 (mapc #'make-preliminary-layout (class-direct-subclasses class))))))))
567 (defmethod shared-initialize :before ((class class) slot-names &key name)
568 (declare (ignore slot-names name))
569 ;; FIXME: Could this just be CLASS instead of `(CLASS ,CLASS)? If not,
570 ;; why not? (See also similar expression in !BOOTSTRAP-INITIALIZE-CLASS.)
571 (setf (slot-value class 'type) `(class ,class))
572 (setf (slot-value class 'class-eq-specializer)
573 (make-instance 'class-eq-specializer :class class)))
575 (defmethod reinitialize-instance :before ((class slot-class) &key)
576 (remove-direct-subclasses class (class-direct-superclasses class))
577 (remove-slot-accessors class (class-direct-slots class)))
579 (defmethod reinitialize-instance :after ((class slot-class)
582 (map-dependents class
584 (apply #'update-dependent class dependent initargs))))
586 (defmethod shared-initialize :after ((class condition-class) slot-names
587 &key direct-slots direct-superclasses)
588 (declare (ignore slot-names))
589 (let ((classoid (find-classoid (class-name class))))
590 (with-slots (wrapper class-precedence-list prototype predicate-name
591 (direct-supers direct-superclasses))
593 (setf (slot-value class 'direct-slots)
594 (mapcar (lambda (pl) (make-direct-slotd class pl))
596 (setf (slot-value class 'finalized-p) t)
597 (setf (classoid-pcl-class classoid) class)
598 (setq direct-supers direct-superclasses)
599 (setq wrapper (classoid-layout classoid))
600 (setq class-precedence-list (compute-class-precedence-list class))
601 (add-direct-subclasses class direct-superclasses)
602 (setq predicate-name (make-class-predicate-name (class-name class)))
603 (make-class-predicate class predicate-name)
604 (setf (slot-value class 'slots) (compute-slots class))))
605 ;; Comment from Gerd's PCL, 2003-05-15:
607 ;; We don't ADD-SLOT-ACCESSORS here because we don't want to
608 ;; override condition accessors with generic functions. We do this
610 (update-pv-table-cache-info class))
612 (defmethod direct-slot-definition-class ((class condition-class)
614 (declare (ignore initargs))
615 (find-class 'condition-direct-slot-definition))
617 (defmethod effective-slot-definition-class ((class condition-class)
619 (declare (ignore initargs))
620 (find-class 'condition-effective-slot-definition))
622 (defmethod finalize-inheritance ((class condition-class))
623 (aver (slot-value class 'finalized-p))
626 (defmethod compute-effective-slot-definition
627 ((class condition-class) slot-name dslotds)
628 (let ((slotd (call-next-method)))
629 (setf (slot-definition-reader-function slotd)
631 (handler-case (condition-reader-function x slot-name)
632 ;; FIXME: FIND-SLOT-DEFAULT throws an error if the slot
633 ;; is unbound; maybe it should be a CELL-ERROR of some
635 (error () (values (slot-unbound class x slot-name))))))
636 (setf (slot-definition-writer-function slotd)
638 (condition-writer-function x v slot-name)))
639 (setf (slot-definition-boundp-function slotd)
641 (multiple-value-bind (v c)
642 (ignore-errors (condition-reader-function x slot-name))
647 (defmethod compute-slots ((class condition-class))
648 (mapcan (lambda (superclass)
649 (mapcar (lambda (dslotd)
650 (compute-effective-slot-definition
651 class (slot-definition-name dslotd) (list dslotd)))
652 (class-direct-slots superclass)))
653 (reverse (slot-value class 'class-precedence-list))))
655 (defmethod compute-slots :around ((class condition-class))
656 (let ((eslotds (call-next-method)))
657 (mapc #'initialize-internal-slot-functions eslotds)
660 (defmethod shared-initialize :after
661 ((slotd structure-slot-definition) slot-names &key
662 (allocation :instance) allocation-class)
663 (declare (ignore slot-names allocation-class))
664 (unless (eq allocation :instance)
665 (error "Structure slots must have :INSTANCE allocation.")))
667 (defun make-structure-class-defstruct-form (name direct-slots include)
668 (let* ((conc-name (format-symbol *package* "~S structure class " name))
669 (constructor (format-symbol *package* "~Aconstructor" conc-name))
670 (defstruct `(defstruct (,name
672 `((:include ,(class-name include))))
674 (:conc-name ,conc-name)
675 (:constructor ,constructor ())
677 ,@(mapcar (lambda (slot)
678 `(,(slot-definition-name slot)
681 (reader-names (mapcar (lambda (slotd)
682 (list 'slot-accessor name
683 (slot-definition-name slotd)
686 (writer-names (mapcar (lambda (slotd)
687 (list 'slot-accessor name
688 (slot-definition-name slotd)
692 (mapcar (lambda (slotd reader-name)
694 (slot-definition-defstruct-accessor-symbol
696 `(defun ,reader-name (obj)
697 (declare (type ,name obj))
699 direct-slots reader-names))
701 (mapcar (lambda (slotd writer-name)
703 (slot-definition-defstruct-accessor-symbol
705 `(defun ,writer-name (nv obj)
706 (declare (type ,name obj))
707 (setf (,accessor obj) nv))))
708 direct-slots writer-names))
712 ,@readers-init ,@writers-init
714 (values defstruct-form constructor reader-names writer-names)))
716 (defun make-defstruct-allocation-function (class)
717 (let ((dd (get-structure-dd (class-name class))))
719 (let ((instance (%make-instance (dd-length dd)))
720 (raw-index (dd-raw-index dd)))
721 (setf (%instance-layout instance)
722 (sb-kernel::compiler-layout-or-lose (dd-name dd)))
724 (setf (%instance-ref instance raw-index)
725 (make-array (dd-raw-length dd)
726 :element-type '(unsigned-byte 32))))
729 (defmethod shared-initialize :after
730 ((class structure-class)
732 &key (direct-superclasses nil direct-superclasses-p)
733 (direct-slots nil direct-slots-p)
734 direct-default-initargs
735 (predicate-name nil predicate-name-p))
736 (declare (ignore slot-names direct-default-initargs))
737 (if direct-superclasses-p
738 (setf (slot-value class 'direct-superclasses)
739 (or direct-superclasses
740 (setq direct-superclasses
741 (and (not (eq (class-name class) 'structure-object))
742 (list *the-class-structure-object*)))))
743 (setq direct-superclasses (slot-value class 'direct-superclasses)))
744 (let* ((name (class-name class))
745 (from-defclass-p (slot-value class 'from-defclass-p))
746 (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
748 (setf (slot-value class 'direct-slots)
752 (let* ((slot-name (getf pl :name))
754 (format-symbol *package*
755 "~S structure class ~A"
757 (setq pl (list* :defstruct-accessor-symbol
759 (make-direct-slotd class pl))
761 (setq direct-slots (slot-value class 'direct-slots)))
763 (let ((include (car (slot-value class 'direct-superclasses))))
764 (multiple-value-bind (defstruct-form constructor reader-names writer-names)
765 (make-structure-class-defstruct-form name direct-slots include)
766 (unless (structure-type-p name) (eval defstruct-form))
767 (mapc (lambda (dslotd reader-name writer-name)
768 (let* ((reader (gdefinition reader-name))
769 (writer (when (gboundp writer-name)
770 (gdefinition writer-name))))
771 (setf (slot-value dslotd 'internal-reader-function)
773 (setf (slot-value dslotd 'internal-writer-function)
775 direct-slots reader-names writer-names)
776 (setf (slot-value class 'defstruct-form) defstruct-form)
777 (setf (slot-value class 'defstruct-constructor) constructor)))
778 (setf (slot-value class 'defstruct-constructor)
779 (make-defstruct-allocation-function class)))
780 (add-direct-subclasses class direct-superclasses)
781 (setf (slot-value class 'class-precedence-list)
782 (compute-class-precedence-list class))
783 (setf (slot-value class 'slots) (compute-slots class))
784 (let ((lclass (find-classoid (class-name class))))
785 (setf (classoid-pcl-class lclass) class)
786 (setf (slot-value class 'wrapper) (classoid-layout lclass)))
787 (setf (slot-value class 'finalized-p) t)
788 (update-pv-table-cache-info class)
789 (setq predicate-name (if predicate-name-p
790 (setf (slot-value class 'predicate-name)
791 (car predicate-name))
792 (or (slot-value class 'predicate-name)
793 (setf (slot-value class 'predicate-name)
794 (make-class-predicate-name
795 (class-name class))))))
796 (make-class-predicate class predicate-name)
797 (add-slot-accessors class direct-slots)))
799 (defmethod direct-slot-definition-class ((class structure-class) &rest initargs)
800 (declare (ignore initargs))
801 (find-class 'structure-direct-slot-definition))
803 (defmethod finalize-inheritance ((class structure-class))
804 nil) ; always finalized
806 (defun add-slot-accessors (class dslotds)
807 (fix-slot-accessors class dslotds 'add))
809 (defun remove-slot-accessors (class dslotds)
810 (fix-slot-accessors class dslotds 'remove))
812 (defun fix-slot-accessors (class dslotds add/remove)
813 ;; We disable package locks here, since defining a class can trigger
814 ;; the update of the accessors of another class -- which might lead
815 ;; to package lock violations if we didn't.
816 (without-package-locks
817 (flet ((fix (gfspec name r/w)
818 (let* ((ll (case r/w (r '(object)) (w '(new-value object))))
819 (gf (if (fboundp gfspec)
820 (ensure-generic-function gfspec)
821 (ensure-generic-function gfspec :lambda-list ll))))
823 (r (if (eq add/remove 'add)
824 (add-reader-method class gf name)
825 (remove-reader-method class gf)))
826 (w (if (eq add/remove 'add)
827 (add-writer-method class gf name)
828 (remove-writer-method class gf)))))))
829 (dolist (dslotd dslotds)
830 (let ((slot-name (slot-definition-name dslotd)))
831 (dolist (r (slot-definition-readers dslotd))
832 (fix r slot-name 'r))
833 (dolist (w (slot-definition-writers dslotd))
834 (fix w slot-name 'w)))))))
836 (defun add-direct-subclasses (class supers)
837 (dolist (super supers)
838 (unless (memq class (class-direct-subclasses class))
839 (add-direct-subclass super class))))
841 (defun remove-direct-subclasses (class supers)
842 (let ((old (class-direct-superclasses class)))
843 (dolist (o (set-difference old supers))
844 (remove-direct-subclass o class))))
846 (defmethod finalize-inheritance ((class std-class))
847 (update-class class t))
849 (defmethod finalize-inheritance ((class forward-referenced-class))
850 ;; FIXME: should we not be thinking a bit about what kinds of error
851 ;; we're throwing? Maybe we need a clos-error type to mix in? Or
852 ;; possibly a forward-referenced-class-error, though that's
853 ;; difficult given e.g. class precedence list calculations...
855 "~@<FINALIZE-INHERITANCE was called on a forward referenced class:~
860 (defun class-has-a-forward-referenced-superclass-p (class)
861 (or (forward-referenced-class-p class)
862 (some #'class-has-a-forward-referenced-superclass-p
863 (class-direct-superclasses class))))
865 ;;; This is called by :after shared-initialize whenever a class is initialized
866 ;;; or reinitialized. The class may or may not be finalized.
867 (defun update-class (class finalizep)
868 ;; Comment from Gerd Moellmann:
870 ;; Note that we can't simply delay the finalization when CLASS has
871 ;; no forward referenced superclasses because that causes bootstrap
873 (without-package-locks
874 (when (and (not finalizep)
875 (not (class-finalized-p class))
876 (not (class-has-a-forward-referenced-superclass-p class)))
877 (finalize-inheritance class)
878 (return-from update-class))
879 (when (or finalizep (class-finalized-p class)
880 (not (class-has-a-forward-referenced-superclass-p class)))
881 (setf (find-class (class-name class)) class)
882 (update-cpl class (compute-class-precedence-list class))
883 ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
884 ;; class. The hoops above are to ensure that FINALIZE-INHERITANCE
885 ;; is called at finalization, so that MOP programmers can hook
886 ;; into the system as described in "Class Finalization Protocol"
887 ;; (section 5.5.2 of AMOP).
888 (update-slots class (compute-slots class))
889 (update-gfs-of-class class)
890 (update-initargs class (compute-default-initargs class))
891 (update-ctors 'finalize-inheritance :class class))
893 (dolist (sub (class-direct-subclasses class)) (update-class sub nil)))))
895 (defun update-cpl (class cpl)
896 (if (class-finalized-p class)
897 (unless (and (equal (class-precedence-list class) cpl)
899 (when (position :class (class-direct-slots c)
900 :key #'slot-definition-allocation)
902 ;; comment from the old CMU CL sources:
903 ;; Need to have the cpl setup before update-lisp-class-layout
904 ;; is called on CMU CL.
905 (setf (slot-value class 'class-precedence-list) cpl)
906 (force-cache-flushes class))
907 (setf (slot-value class 'class-precedence-list) cpl))
908 (update-class-can-precede-p cpl))
910 (defun update-class-can-precede-p (cpl)
912 (let ((first (car cpl)))
913 (dolist (c (cdr cpl))
914 (pushnew c (slot-value first 'can-precede-list))))
915 (update-class-can-precede-p (cdr cpl))))
917 (defun class-can-precede-p (class1 class2)
918 (member class2 (class-can-precede-list class1)))
920 (defun update-slots (class eslotds)
921 (let ((instance-slots ())
923 (dolist (eslotd eslotds)
924 (let ((alloc (slot-definition-allocation eslotd)))
926 (:instance (push eslotd instance-slots))
927 (:class (push eslotd class-slots)))))
929 ;; If there is a change in the shape of the instances then the
930 ;; old class is now obsolete.
931 (let* ((nlayout (mapcar #'slot-definition-name
932 (sort instance-slots #'<
933 :key #'slot-definition-location)))
934 (nslots (length nlayout))
935 (nwrapper-class-slots (compute-class-slots class-slots))
936 (owrapper (when (class-finalized-p class)
937 (class-wrapper class)))
938 (olayout (when owrapper
939 (wrapper-instance-slots-layout owrapper)))
940 (owrapper-class-slots (and owrapper (wrapper-class-slots owrapper)))
942 (cond ((null owrapper)
943 (make-wrapper nslots class))
944 ((and (equal nlayout olayout)
946 (loop for o in owrapper-class-slots
947 for n in nwrapper-class-slots
948 do (unless (eq (car o) (car n)) (return t)))))
951 ;; This will initialize the new wrapper to have the
952 ;; same state as the old wrapper. We will then have
953 ;; to change that. This may seem like wasted work
954 ;; (and it is), but the spec requires that we call
955 ;; MAKE-INSTANCES-OBSOLETE.
956 (make-instances-obsolete class)
957 (class-wrapper class)))))
959 (with-slots (wrapper slots) class
960 (update-lisp-class-layout class nwrapper)
962 (wrapper-instance-slots-layout nwrapper) nlayout
963 (wrapper-class-slots nwrapper) nwrapper-class-slots
964 (wrapper-no-of-instance-slots nwrapper) nslots
966 (setf (slot-value class 'finalized-p) t)
967 (unless (eq owrapper nwrapper)
968 (update-pv-table-cache-info class)
969 (maybe-update-standard-class-locations class)))))
971 (defun compute-class-slots (eslotds)
973 (dolist (eslotd eslotds)
974 (push (assoc (slot-definition-name eslotd)
975 (class-slot-cells (slot-definition-class eslotd)))
979 (defun update-gfs-of-class (class)
980 (when (and (class-finalized-p class)
981 (let ((cpl (class-precedence-list class)))
982 (or (member *the-class-slot-class* cpl)
983 (member *the-class-standard-effective-slot-definition*
985 (let ((gf-table (make-hash-table :test 'eq)))
986 (labels ((collect-gfs (class)
987 (dolist (gf (specializer-direct-generic-functions class))
988 (setf (gethash gf gf-table) t))
989 (mapc #'collect-gfs (class-direct-superclasses class))))
991 (maphash (lambda (gf ignore)
992 (declare (ignore ignore))
993 (update-gf-dfun class gf))
996 (defun update-initargs (class inits)
997 (setf (plist-value class 'default-initargs) inits))
999 (defmethod compute-default-initargs ((class slot-class))
1000 (let ((initargs (loop for c in (class-precedence-list class)
1001 append (class-direct-default-initargs c))))
1002 (delete-duplicates initargs :test #'eq :key #'car :from-end t)))
1004 ;;;; protocols for constructing direct and effective slot definitions
1006 (defmethod direct-slot-definition-class ((class std-class) &rest initargs)
1007 (declare (ignore initargs))
1008 (find-class 'standard-direct-slot-definition))
1010 (defun make-direct-slotd (class initargs)
1011 (let ((initargs (list* :class class initargs)))
1012 (apply #'make-instance
1013 (apply #'direct-slot-definition-class class initargs)
1016 (defmethod compute-slots ((class std-class))
1017 ;; As specified, we must call COMPUTE-EFFECTIVE-SLOT-DEFINITION once
1018 ;; for each different slot name we find in our superclasses. Each
1019 ;; call receives the class and a list of the dslotds with that name.
1020 ;; The list is in most-specific-first order.
1021 (let ((name-dslotds-alist ()))
1022 (dolist (c (class-precedence-list class))
1023 (dolist (slot (class-direct-slots c))
1024 (let* ((name (slot-definition-name slot))
1025 (entry (assq name name-dslotds-alist)))
1027 (push slot (cdr entry))
1028 (push (list name slot) name-dslotds-alist)))))
1029 (mapcar (lambda (direct)
1030 (compute-effective-slot-definition class
1032 (nreverse (cdr direct))))
1033 name-dslotds-alist)))
1035 (defmethod compute-slots ((class standard-class))
1038 (defmethod compute-slots :around ((class standard-class))
1039 (let ((eslotds (call-next-method))
1041 (dolist (eslotd eslotds eslotds)
1042 (setf (slot-definition-location eslotd)
1043 (case (slot-definition-allocation eslotd)
1047 (let* ((name (slot-definition-name eslotd))
1050 (slot-definition-allocation-class eslotd)
1051 ;; we get here if the user adds an extra slot
1053 (setf (slot-definition-allocation-class eslotd)
1055 ;; which raises the question of what we should
1056 ;; do if we find that said user has added a slot
1057 ;; with the same name as another slot...
1058 (cell (or (assq name (class-slot-cells from-class))
1059 (setf (class-slot-cells from-class)
1060 (cons (cons name +slot-unbound+)
1061 (class-slot-cells from-class))))))
1063 (if (eq +slot-unbound+ (cdr cell))
1064 ;; We may have inherited an initfunction
1065 (let ((initfun (slot-definition-initfunction eslotd)))
1067 (rplacd cell (funcall initfun))
1070 (unless (slot-definition-class eslotd)
1071 (setf (slot-definition-class eslotd) class))
1072 (initialize-internal-slot-functions eslotd))))
1074 (defmethod compute-slots ((class funcallable-standard-class))
1077 (defmethod compute-slots :around ((class funcallable-standard-class))
1078 (labels ((instance-slot-names (slotds)
1080 (dolist (slotd slotds (nreverse collect))
1081 (when (eq (slot-definition-allocation slotd) :instance)
1082 (push (slot-definition-name slotd) collect)))))
1083 ;; This sorts slots so that slots of classes later in the CPL
1084 ;; come before slots of other classes. This is crucial for
1085 ;; funcallable instances because it ensures that the slots of
1086 ;; FUNCALLABLE-STANDARD-OBJECT, which includes the slots of
1087 ;; KERNEL:FUNCALLABLE-INSTANCE, come first, which in turn
1088 ;; makes it possible to treat FUNCALLABLE-STANDARD-OBJECT as
1089 ;; a funcallable instance.
1090 (compute-layout (eslotds)
1092 (names (instance-slot-names eslotds)))
1094 (reverse (class-precedence-list class))
1095 (nreverse (nconc names first)))
1096 (dolist (ss (class-slots class))
1097 (let ((name (slot-definition-name ss)))
1098 (when (member name names)
1100 (setq names (delete name names)))))))))
1101 (let ((all-slotds (call-next-method))
1104 (dolist (slotd all-slotds)
1105 (case (slot-definition-allocation slotd)
1106 (:instance (push slotd instance-slots))
1107 (:class (push slotd class-slots))))
1108 (let ((layout (compute-layout instance-slots)))
1109 (dolist (slotd instance-slots)
1110 (setf (slot-definition-location slotd)
1111 (position (slot-definition-name slotd) layout))
1112 (initialize-internal-slot-functions slotd)))
1113 (dolist (slotd class-slots)
1114 (let ((name (slot-definition-name slotd))
1115 (from-class (slot-definition-allocation-class slotd)))
1116 (setf (slot-definition-location slotd)
1117 (assoc name (class-slot-cells from-class)))
1118 (aver (consp (slot-definition-location slotd)))
1119 (initialize-internal-slot-functions slotd)))
1122 (defmethod compute-slots ((class structure-class))
1123 (mapcan (lambda (superclass)
1124 (mapcar (lambda (dslotd)
1125 (compute-effective-slot-definition
1127 (slot-definition-name dslotd)
1129 (class-direct-slots superclass)))
1130 (reverse (slot-value class 'class-precedence-list))))
1132 (defmethod compute-slots :around ((class structure-class))
1133 (let ((eslotds (call-next-method)))
1134 (mapc #'initialize-internal-slot-functions eslotds)
1137 (defmethod compute-effective-slot-definition ((class slot-class) name dslotds)
1138 (declare (ignore name))
1139 (let* ((initargs (compute-effective-slot-definition-initargs class dslotds))
1140 (class (apply #'effective-slot-definition-class class initargs)))
1141 (apply #'make-instance class initargs)))
1143 (defmethod effective-slot-definition-class ((class std-class) &rest initargs)
1144 (declare (ignore initargs))
1145 (find-class 'standard-effective-slot-definition))
1147 (defmethod effective-slot-definition-class ((class structure-class) &rest initargs)
1148 (declare (ignore initargs))
1149 (find-class 'structure-effective-slot-definition))
1151 (defmethod compute-effective-slot-definition-initargs
1152 ((class slot-class) direct-slotds)
1158 (allocation-class nil)
1164 (dolist (slotd direct-slotds)
1167 (setq name (slot-definition-name slotd)
1170 (when (slot-definition-initfunction slotd)
1171 (setq initform (slot-definition-initform slotd)
1172 initfunction (slot-definition-initfunction slotd)
1175 (setq allocation (slot-definition-allocation slotd)
1176 allocation-class (slot-definition-class slotd)
1178 (setq initargs (append (slot-definition-initargs slotd) initargs))
1179 (let ((slotd-type (slot-definition-type slotd)))
1180 (setq type (cond ((eq type t) slotd-type)
1181 ((*subtypep type slotd-type) type)
1182 (t `(and ,type ,slotd-type)))))))
1185 :initfunction initfunction
1187 :allocation allocation
1188 :allocation-class allocation-class
1192 (defmethod compute-effective-slot-definition-initargs :around
1193 ((class structure-class) direct-slotds)
1194 (let ((slotd (car direct-slotds)))
1195 (list* :defstruct-accessor-symbol
1196 (slot-definition-defstruct-accessor-symbol slotd)
1197 :internal-reader-function
1198 (slot-definition-internal-reader-function slotd)
1199 :internal-writer-function
1200 (slot-definition-internal-writer-function slotd)
1201 (call-next-method))))
1203 ;;; NOTE: For bootstrapping considerations, these can't use MAKE-INSTANCE
1204 ;;; to make the method object. They have to use make-a-method which
1205 ;;; is a specially bootstrapped mechanism for making standard methods.
1206 (defmethod reader-method-class ((class slot-class) direct-slot &rest initargs)
1207 (declare (ignore direct-slot initargs))
1208 (find-class 'standard-reader-method))
1210 (defmethod add-reader-method ((class slot-class) generic-function slot-name)
1211 (add-method generic-function
1212 (make-a-method 'standard-reader-method
1214 (list (or (class-name class) 'object))
1216 (make-reader-method-function class slot-name)
1217 "automatically generated reader method"
1220 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
1221 (declare (ignore direct-slot initargs))
1222 (find-class 'standard-writer-method))
1224 (defmethod add-writer-method ((class slot-class) generic-function slot-name)
1225 (add-method generic-function
1226 (make-a-method 'standard-writer-method
1228 (list 'new-value (or (class-name class) 'object))
1229 (list *the-class-t* class)
1230 (make-writer-method-function class slot-name)
1231 "automatically generated writer method"
1234 (defmethod add-boundp-method ((class slot-class) generic-function slot-name)
1235 (add-method generic-function
1236 (make-a-method 'standard-boundp-method
1238 (list (or (class-name class) 'object))
1240 (make-boundp-method-function class slot-name)
1241 "automatically generated boundp method"
1244 (defmethod remove-reader-method ((class slot-class) generic-function)
1245 (let ((method (get-method generic-function () (list class) nil)))
1246 (when method (remove-method generic-function method))))
1248 (defmethod remove-writer-method ((class slot-class) generic-function)
1250 (get-method generic-function () (list *the-class-t* class) nil)))
1251 (when method (remove-method generic-function method))))
1253 (defmethod remove-boundp-method ((class slot-class) generic-function)
1254 (let ((method (get-method generic-function () (list class) nil)))
1255 (when method (remove-method generic-function method))))
1257 ;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITE-METHOD function are NOT
1258 ;;; part of the standard protocol. They are however useful, PCL makes
1259 ;;; use of them internally and documents them for PCL users.
1261 ;;; *** This needs work to make type testing by the writer functions which
1262 ;;; *** do type testing faster. The idea would be to have one constructor
1263 ;;; *** for each possible type test.
1265 ;;; *** There is a subtle bug here which is going to have to be fixed.
1266 ;;; *** Namely, the simplistic use of the template has to be fixed. We
1267 ;;; *** have to give the OPTIMIZE-SLOT-VALUE method the user might have
1268 ;;; *** defined for this metaclass a chance to run.
1270 (defmethod make-reader-method-function ((class slot-class) slot-name)
1271 (make-std-reader-method-function (class-name class) slot-name))
1273 (defmethod make-writer-method-function ((class slot-class) slot-name)
1274 (make-std-writer-method-function (class-name class) slot-name))
1276 (defmethod make-boundp-method-function ((class slot-class) slot-name)
1277 (make-std-boundp-method-function (class-name class) slot-name))
1279 (defmethod compatible-meta-class-change-p (class proto-new-class)
1280 (eq (class-of class) (class-of proto-new-class)))
1282 (defmethod validate-superclass ((class class) (new-super class))
1283 (or (eq new-super *the-class-t*)
1284 (eq (class-of class) (class-of new-super))))
1286 (defmethod validate-superclass ((class standard-class) (new-super std-class))
1287 (let ((new-super-meta-class (class-of new-super)))
1288 (or (eq new-super-meta-class *the-class-std-class*)
1289 (eq (class-of class) new-super-meta-class))))
1291 ;;; What this does depends on which of the four possible values of
1292 ;;; LAYOUT-INVALID the PCL wrapper has; the simplest case is when it
1293 ;;; is (:FLUSH <wrapper>) or (:OBSOLETE <wrapper>), when there is
1294 ;;; nothing to do, as the new wrapper has already been created. If
1295 ;;; LAYOUT-INVALID returns NIL, then we invalidate it (setting it to
1296 ;;; (:FLUSH <wrapper>); UPDATE-SLOTS later gets to choose whether or
1297 ;;; not to "upgrade" this to (:OBSOLETE <wrapper>).
1299 ;;; This leaves the case where LAYOUT-INVALID returns T, which happens
1300 ;;; when REGISTER-LAYOUT has invalidated a superclass of CLASS (which
1301 ;;; invalidated all the subclasses in SB-KERNEL land). Again, here we
1302 ;;; must flush the caches and allow UPDATE-SLOTS to decide whether to
1303 ;;; obsolete the wrapper.
1305 ;;; FIXME: either here or in INVALID-WRAPPER-P looks like a good place
1306 ;;; for (AVER (NOT (EQ (LAYOUT-INVALID OWRAPPER)
1307 ;;; :UNINITIALIZED)))
1309 ;;; Thanks to Gerd Moellmann for the explanation. -- CSR, 2002-10-29
1310 (defun force-cache-flushes (class)
1311 (let* ((owrapper (class-wrapper class)))
1312 ;; We only need to do something if the wrapper is still valid. If
1313 ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
1314 ;; both of those will already be doing what we want. In
1315 ;; particular, we must be sure we never change an OBSOLETE into a
1316 ;; FLUSH since OBSOLETE means do what FLUSH does and then some.
1317 (when (or (not (invalid-wrapper-p owrapper))
1318 ;; KLUDGE: despite the observations above, this remains
1319 ;; a violation of locality or what might be considered
1320 ;; good style. There has to be a better way! -- CSR,
1322 (eq (layout-invalid owrapper) t))
1323 (let ((nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1325 (setf (wrapper-instance-slots-layout nwrapper)
1326 (wrapper-instance-slots-layout owrapper))
1327 (setf (wrapper-class-slots nwrapper)
1328 (wrapper-class-slots owrapper))
1330 (update-lisp-class-layout class nwrapper)
1331 (setf (slot-value class 'wrapper) nwrapper)
1332 ;; Use :OBSOLETE instead of :FLUSH if any superclass has
1334 (if (find-if (lambda (x)
1335 (and (consp x) (eq :obsolete (car x))))
1336 (layout-inherits owrapper)
1337 :key #'layout-invalid)
1338 (invalidate-wrapper owrapper :obsolete nwrapper)
1339 (invalidate-wrapper owrapper :flush nwrapper)))))))
1341 (defun flush-cache-trap (owrapper nwrapper instance)
1342 (declare (ignore owrapper))
1343 (set-wrapper instance nwrapper))
1345 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
1346 ;;; the next access to the instance (as defined in 88-002R) to trap
1347 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
1348 (defmethod make-instances-obsolete ((class std-class))
1349 (let* ((owrapper (class-wrapper class))
1350 (nwrapper (make-wrapper (wrapper-no-of-instance-slots owrapper)
1352 (setf (wrapper-instance-slots-layout nwrapper)
1353 (wrapper-instance-slots-layout owrapper))
1354 (setf (wrapper-class-slots nwrapper)
1355 (wrapper-class-slots owrapper))
1357 (update-lisp-class-layout class nwrapper)
1358 (setf (slot-value class 'wrapper) nwrapper)
1359 (invalidate-wrapper owrapper :obsolete nwrapper)
1362 (defmethod make-instances-obsolete ((class symbol))
1363 (make-instances-obsolete (find-class class))
1364 ;; ANSI wants the class name when called with a symbol.
1367 ;;; OBSOLETE-INSTANCE-TRAP is the internal trap that is called when we
1368 ;;; see an obsolete instance. The times when it is called are:
1369 ;;; - when the instance is involved in method lookup
1370 ;;; - when attempting to access a slot of an instance
1372 ;;; It is not called by class-of, wrapper-of, or any of the low-level
1373 ;;; instance access macros.
1375 ;;; Of course these times when it is called are an internal
1376 ;;; implementation detail of PCL and are not part of the documented
1377 ;;; description of when the obsolete instance update happens. The
1378 ;;; documented description is as it appears in 88-002R.
1380 ;;; This has to return the new wrapper, so it counts on all the
1381 ;;; methods on obsolete-instance-trap-internal to return the new
1382 ;;; wrapper. It also does a little internal error checking to make
1383 ;;; sure that the traps are only happening when they should, and that
1384 ;;; the trap methods are computing appropriate new wrappers.
1386 ;;; OBSOLETE-INSTANCE-TRAP might be called on structure instances
1387 ;;; after a structure is redefined. In most cases,
1388 ;;; OBSOLETE-INSTANCE-TRAP will not be able to fix the old instance,
1389 ;;; so it must signal an error. The hard part of this is that the
1390 ;;; error system and debugger might cause OBSOLETE-INSTANCE-TRAP to be
1391 ;;; called again, so in that case, we have to return some reasonable
1392 ;;; wrapper, instead.
1394 (defvar *in-obsolete-instance-trap* nil)
1395 (defvar *the-wrapper-of-structure-object*
1396 (class-wrapper (find-class 'structure-object)))
1398 (define-condition obsolete-structure (error)
1399 ((datum :reader obsolete-structure-datum :initarg :datum))
1401 (lambda (condition stream)
1402 ;; Don't try to print the structure, since it probably won't work.
1404 "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
1405 (type-of (obsolete-structure-datum condition))))))
1407 (defun obsolete-instance-trap (owrapper nwrapper instance)
1408 (if (not (pcl-instance-p instance))
1409 (if *in-obsolete-instance-trap*
1410 *the-wrapper-of-structure-object*
1411 (let ((*in-obsolete-instance-trap* t))
1412 (error 'obsolete-structure :datum instance)))
1413 (let* ((class (wrapper-class* nwrapper))
1414 (copy (allocate-instance class)) ;??? allocate-instance ???
1415 (olayout (wrapper-instance-slots-layout owrapper))
1416 (nlayout (wrapper-instance-slots-layout nwrapper))
1417 (oslots (get-slots instance))
1418 (nslots (get-slots copy))
1419 (oclass-slots (wrapper-class-slots owrapper))
1424 ;; local --> local transfer value
1425 ;; local --> shared discard value, discard slot
1426 ;; local --> -- discard slot
1427 ;; shared --> local transfer value
1428 ;; shared --> shared -- (cf SHARED-INITIALIZE :AFTER STD-CLASS)
1429 ;; shared --> -- discard value
1430 ;; -- --> local add slot
1433 ;; Collect class slots from inherited wrappers. Needed for
1434 ;; shared -> local transfers of inherited slots.
1435 (let ((inherited (layout-inherits owrapper)))
1436 (loop for i from (1- (length inherited)) downto 0
1437 for layout = (aref inherited i)
1438 when (typep layout 'wrapper)
1439 do (dolist (slot (wrapper-class-slots layout))
1440 (pushnew slot oclass-slots :key #'car))))
1442 ;; Go through all the old local slots.
1444 (dolist (name olayout)
1445 (let ((npos (posq name nlayout)))
1447 (setf (clos-slots-ref nslots npos)
1448 (clos-slots-ref oslots opos))
1450 (push name discarded)
1451 (unless (eq (clos-slots-ref oslots opos) +slot-unbound+)
1452 (setf (getf plist name) (clos-slots-ref oslots opos))))))
1455 ;; Go through all the old shared slots.
1456 (dolist (oclass-slot-and-val oclass-slots)
1457 (let ((name (car oclass-slot-and-val))
1458 (val (cdr oclass-slot-and-val)))
1459 (let ((npos (posq name nlayout)))
1461 (setf (clos-slots-ref nslots npos) val)))))
1463 ;; Go through all the new local slots to compute the added slots.
1464 (dolist (nlocal nlayout)
1465 (unless (or (memq nlocal olayout)
1466 (assq nlocal oclass-slots))
1467 (push nlocal added)))
1469 (swap-wrappers-and-slots instance copy)
1471 (update-instance-for-redefined-class instance
1477 (defun change-class-internal (instance new-class initargs)
1478 (let* ((old-class (class-of instance))
1479 (copy (allocate-instance new-class))
1480 (new-wrapper (get-wrapper copy))
1481 (old-wrapper (class-wrapper old-class))
1482 (old-layout (wrapper-instance-slots-layout old-wrapper))
1483 (new-layout (wrapper-instance-slots-layout new-wrapper))
1484 (old-slots (get-slots instance))
1485 (new-slots (get-slots copy))
1486 (old-class-slots (wrapper-class-slots old-wrapper)))
1488 ;; "The values of local slots specified by both the class CTO and
1489 ;; CFROM are retained. If such a local slot was unbound, it
1490 ;; remains unbound."
1491 (let ((new-position 0))
1492 (dolist (new-slot new-layout)
1493 (let ((old-position (posq new-slot old-layout)))
1495 (setf (clos-slots-ref new-slots new-position)
1496 (clos-slots-ref old-slots old-position))))
1497 (incf new-position)))
1499 ;; "The values of slots specified as shared in the class CFROM and
1500 ;; as local in the class CTO are retained."
1501 (dolist (slot-and-val old-class-slots)
1502 (let ((position (posq (car slot-and-val) new-layout)))
1504 (setf (clos-slots-ref new-slots position) (cdr slot-and-val)))))
1506 ;; Make the copy point to the old instance's storage, and make the
1507 ;; old instance point to the new storage.
1508 (swap-wrappers-and-slots instance copy)
1510 (apply #'update-instance-for-different-class copy instance initargs)
1513 (defmethod change-class ((instance standard-object)
1514 (new-class standard-class)
1516 (change-class-internal instance new-class initargs))
1518 (defmethod change-class ((instance funcallable-standard-object)
1519 (new-class funcallable-standard-class)
1521 (change-class-internal instance new-class initargs))
1523 (defmethod change-class ((instance standard-object)
1524 (new-class funcallable-standard-class)
1526 (declare (ignore initargs))
1527 (error "You can't change the class of ~S to ~S~@
1528 because it isn't already an instance with metaclass ~S."
1529 instance new-class 'standard-class))
1531 (defmethod change-class ((instance funcallable-standard-object)
1532 (new-class standard-class)
1534 (declare (ignore initargs))
1535 (error "You can't change the class of ~S to ~S~@
1536 because it isn't already an instance with metaclass ~S."
1537 instance new-class 'funcallable-standard-class))
1539 (defmethod change-class ((instance t) (new-class-name symbol) &rest initargs)
1540 (apply #'change-class instance (find-class new-class-name) initargs))
1542 ;;;; The metaclass BUILT-IN-CLASS
1544 ;;;; This metaclass is something of a weird creature. By this point, all
1545 ;;;; instances of it which will exist have been created, and no instance
1546 ;;;; is ever created by calling MAKE-INSTANCE.
1548 ;;;; But, there are other parts of the protocol we must follow and those
1549 ;;;; definitions appear here.
1551 (defmethod shared-initialize :before
1552 ((class built-in-class) slot-names &rest initargs)
1553 (declare (ignore slot-names initargs))
1554 (error "attempt to initialize or reinitialize a built in class"))
1556 (defmethod class-direct-slots ((class built-in-class)) ())
1557 (defmethod class-slots ((class built-in-class)) ())
1558 (defmethod class-direct-default-initargs ((class built-in-class)) ())
1559 (defmethod class-default-initargs ((class built-in-class)) ())
1561 (defmethod validate-superclass ((c class) (s built-in-class))
1562 (or (eq s *the-class-t*)
1563 (eq s *the-class-stream*)))
1565 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
1566 (defmethod class-direct-slots ((class forward-referenced-class)) ())
1567 (defmethod class-direct-default-initargs ((class forward-referenced-class)) ())
1568 (macrolet ((def (method)
1569 `(defmethod ,method ((class forward-referenced-class))
1570 (error "~@<~I~S was called on a forward referenced class:~2I~_~S~:>"
1572 (def class-default-initargs)
1573 (def class-precedence-list)
1576 (defmethod validate-superclass ((c slot-class)
1577 (f forward-referenced-class))
1580 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
1581 (pushnew dependent (plist-value metaobject 'dependents)))
1583 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
1584 (setf (plist-value metaobject 'dependents)
1585 (delete dependent (plist-value metaobject 'dependents))))
1587 (defmethod map-dependents ((metaobject dependent-update-mixin) function)
1588 (dolist (dependent (plist-value metaobject 'dependents))
1589 (funcall function dependent)))