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 (dolist (type '(reader writer boundp))
77 (let* ((gf-name (ecase type
78 (reader 'slot-value-using-class)
79 (writer '(setf slot-value-using-class))
80 (boundp 'slot-boundp-using-class)))
81 (gf (gdefinition gf-name)))
82 (compute-slot-accessor-info slotd type gf)))))
84 ;;; CMUCL (Gerd PCL 2003-04-25) comment:
86 ;;; Compute an effective method for SLOT-VALUE-USING-CLASS, (SETF
87 ;;; SLOT-VALUE-USING-CLASS) or SLOT-BOUNDP-USING-CLASS for reading/
88 ;;; writing/testing effective slot SLOTD.
90 ;;; TYPE is one of the symbols READER, WRITER or BOUNDP, depending on
91 ;;; GF. Store the effective method in the effective slot definition
92 ;;; object itself; these GFs have special dispatch functions calling
93 ;;; effective methods directly retrieved from effective slot
94 ;;; definition objects, as an optimization.
96 ;;; FIXME: Change the function name to COMPUTE-SVUC-SLOTD-FUNCTION,
98 (defmethod compute-slot-accessor-info ((slotd effective-slot-definition)
100 (let* ((name (slot-value slotd 'name))
101 (class (slot-value slotd '%class))
102 (old-slotd (when (class-finalized-p class)
103 (find-slot-definition class name)))
104 (old-std-p (and old-slotd (slot-accessor-std-p old-slotd 'all))))
105 (multiple-value-bind (function std-p)
106 (if (eq *boot-state* 'complete)
107 (get-accessor-method-function gf type class slotd)
108 (get-optimized-std-accessor-method-function class slotd type))
109 (setf (slot-accessor-std-p slotd type) std-p)
110 (setf (slot-accessor-function slotd type) function))))
112 (defmethod slot-definition-allocation ((slotd structure-slot-definition))
115 ;;;; various class accessors that are a little more complicated than can be
116 ;;;; done with automatically generated reader methods
118 (defmethod class-prototype :before (class)
119 (unless (class-finalized-p class)
120 (error "~@<~S is not finalized.~:@>" class)))
122 ;;; KLUDGE: For some reason factoring the common body into a function
123 ;;; breaks PCL bootstrapping, so just generate it with a macrolet for
125 (macrolet ((def (class)
126 `(defmethod class-prototype ((class ,class))
127 (with-slots (prototype) class
129 (setf prototype (allocate-instance class)))))))
131 (def condition-class)
132 (def structure-class))
134 (defmethod class-direct-default-initargs ((class slot-class))
135 (plist-value class 'direct-default-initargs))
137 (defmethod class-default-initargs ((class slot-class))
138 (plist-value class 'default-initargs))
140 (defmethod class-slot-cells ((class std-class))
141 (plist-value class 'class-slot-cells))
142 (defmethod (setf class-slot-cells) (new-value (class std-class))
143 (setf (plist-value class 'class-slot-cells) new-value))
145 ;;;; class accessors that are even a little bit more complicated than those
146 ;;;; above. These have a protocol for updating them, we must implement that
149 ;;; Maintaining the direct subclasses backpointers. The update methods are
150 ;;; here, the values are read by an automatically generated reader method.
151 (defmethod add-direct-subclass ((class class) (subclass class))
152 (with-slots (direct-subclasses) class
153 (pushnew subclass direct-subclasses :test #'eq)
155 (defmethod remove-direct-subclass ((class class) (subclass class))
156 (with-slots (direct-subclasses) class
157 (setq direct-subclasses (remove subclass direct-subclasses))
160 ;;; Maintaining the direct-methods and direct-generic-functions backpointers.
162 ;;; There are four generic functions involved, each has one method for the
163 ;;; class case and another method for the damned EQL specializers. All of
164 ;;; these are specified methods and appear in their specified place in the
167 ;;; ADD-DIRECT-METHOD
168 ;;; REMOVE-DIRECT-METHOD
169 ;;; SPECIALIZER-DIRECT-METHODS
170 ;;; SPECIALIZER-DIRECT-GENERIC-FUNCTIONS
172 ;;; In each case, we maintain one value which is a cons. The car is the list
173 ;;; methods. The cdr is a list of the generic functions. The cdr is always
176 ;;; This needs to be used recursively, in case a non-trivial user
177 ;;; defined ADD/REMOVE-DIRECT-METHOD method ends up calling another
178 ;;; function using the same lock.
179 (defvar *specializer-lock* (sb-thread::make-spinlock :name "Specializer lock"))
181 (defmethod add-direct-method :around ((specializer specializer) method)
182 ;; All the actions done under this lock are done in an order
183 ;; that is safe to unwind at any point.
184 (sb-thread::with-recursive-spinlock (*specializer-lock*)
187 (defmethod remove-direct-method :around ((specializer specializer) method)
188 ;; All the actions done under this lock are done in an order
189 ;; that is safe to unwind at any point.
190 (sb-thread::with-recursive-spinlock (*specializer-lock*)
193 (defmethod add-direct-method ((specializer class) (method method))
194 (let ((cell (slot-value specializer 'direct-methods)))
195 ;; We need to first smash the CDR, because a parallel read may
196 ;; be in progress, and because if an interrupt catches us we
197 ;; need to have a consistent state.
199 (car cell) (adjoin method (car cell) :test #'eq)))
202 (defmethod remove-direct-method ((specializer class) (method method))
203 (let ((cell (slot-value specializer 'direct-methods)))
204 ;; We need to first smash the CDR, because a parallel read may
205 ;; be in progress, and because if an interrupt catches us we
206 ;; need to have a consistent state.
208 (car cell) (remove method (car cell))))
211 (defmethod specializer-direct-methods ((specializer class))
212 (with-slots (direct-methods) specializer
213 (car direct-methods)))
215 (defmethod specializer-direct-generic-functions ((specializer class))
216 (let ((cell (slot-value specializer 'direct-methods)))
217 ;; If an ADD/REMOVE-METHOD is in progress, no matter: either
218 ;; we behave as if we got just first or just after -- it's just
219 ;; for update that we need to lock.
221 (sb-thread::with-spinlock (*specializer-lock*)
224 (dolist (m (car cell))
225 ;; the old PCL code used COLLECTING-ONCE which used
226 ;; #'EQ to check for newness
227 (pushnew (method-generic-function m) collect :test #'eq))
228 (nreverse collect)))))))
230 ;;; This hash table is used to store the direct methods and direct generic
231 ;;; functions of EQL specializers. Each value in the table is the cons.
233 ;;; These tables are shared between threads, so they need to be synchronized.
234 (defvar *eql-specializer-methods* (make-hash-table :test 'eql :synchronized t))
235 (defvar *class-eq-specializer-methods* (make-hash-table :test 'eq :synchronized t))
237 (defmethod specializer-method-table ((specializer eql-specializer))
238 *eql-specializer-methods*)
240 (defmethod specializer-method-table ((specializer class-eq-specializer))
241 *class-eq-specializer-methods*)
243 (defmethod add-direct-method ((specializer specializer-with-object)
245 (let* ((object (specializer-object specializer))
246 (table (specializer-method-table specializer))
247 (entry (gethash object table)))
250 (setf (gethash object table) (cons nil nil))))
251 ;; We need to first smash the CDR, because a parallel read may
252 ;; be in progress, and because if an interrupt catches us we
253 ;; need to have a consistent state.
255 (car entry) (adjoin method (car entry) :test #'eq))
258 (defmethod remove-direct-method ((specializer specializer-with-object)
260 (let* ((object (specializer-object specializer))
261 (entry (gethash object (specializer-method-table specializer))))
263 ;; We need to first smash the CDR, because a parallel read may
264 ;; be in progress, and because if an interrupt catches us we
265 ;; need to have a consistent state.
267 (car entry) (remove method (car entry))))
270 (defmethod specializer-direct-methods ((specializer specializer-with-object))
271 (car (gethash (specializer-object specializer)
272 (specializer-method-table specializer))))
274 (defmethod specializer-direct-generic-functions ((specializer
275 specializer-with-object))
276 (let* ((object (specializer-object specializer))
277 (entry (gethash object (specializer-method-table specializer))))
280 (sb-thread::with-spinlock (*specializer-lock*)
283 (dolist (m (car entry))
284 (pushnew (method-generic-function m) collect :test #'eq))
285 (nreverse collect))))))))
287 (defun map-specializers (function)
288 (map-all-classes (lambda (class)
289 (funcall function (class-eq-specializer class))
290 (funcall function class)))
291 (maphash (lambda (object methods)
292 (declare (ignore methods))
293 (intern-eql-specializer object))
294 *eql-specializer-methods*)
295 (maphash (lambda (object specl)
296 (declare (ignore object))
297 (funcall function specl))
298 *eql-specializer-table*)
301 (defun map-all-generic-functions (function)
302 (let ((all-generic-functions (make-hash-table :test 'eq)))
303 (map-specializers (lambda (specl)
304 (dolist (gf (specializer-direct-generic-functions
306 (unless (gethash gf all-generic-functions)
307 (setf (gethash gf all-generic-functions) t)
308 (funcall function gf))))))
311 (defmethod shared-initialize :after ((specl class-eq-specializer)
314 (declare (ignore slot-names))
315 (setf (slot-value specl '%type) `(class-eq ,(specializer-class specl))))
317 (defmethod shared-initialize :after ((specl eql-specializer) slot-names &key)
318 (declare (ignore slot-names))
319 (setf (slot-value specl '%type)
320 `(eql ,(specializer-object specl)))
321 (setf (info :type :translator specl)
322 (constantly (make-member-type :members (list (specializer-object specl))))))
324 (defun real-load-defclass (name metaclass-name supers slots other
325 readers writers slot-names source-location safe-p)
326 (with-single-package-locked-error (:symbol name "defining ~S as a class")
327 (%compiler-defclass name readers writers slot-names)
328 (let ((res (apply #'ensure-class name :metaclass metaclass-name
329 :direct-superclasses supers
331 :definition-source source-location
336 (setf (gdefinition 'load-defclass) #'real-load-defclass)
338 (defun ensure-class (name &rest args)
340 (apply #'ensure-class-using-class
341 (let ((class (find-class name nil)))
342 (when (and class (eq name (class-name class)))
343 ;; NAME is the proper name of CLASS, so redefine it
348 (defmethod ensure-class-using-class ((class null) name &rest args &key)
350 (multiple-value-bind (meta initargs)
351 (frob-ensure-class-args args)
352 (setf class (apply #'make-instance meta :name name initargs))
353 (without-package-locks
354 (setf (find-class name) class))))
355 ;; After boot (SETF FIND-CLASS) does this.
356 (unless (eq *boot-state* 'complete)
357 (%set-class-type-translation class name))
360 (defmethod ensure-class-using-class ((class pcl-class) name &rest args &key)
362 (multiple-value-bind (meta initargs)
363 (frob-ensure-class-args args)
364 (unless (eq (class-of class) meta)
365 (apply #'change-class class meta initargs))
366 (apply #'reinitialize-instance class initargs)
367 (without-package-locks
368 (setf (find-class name) class))))
369 ;; After boot (SETF FIND-CLASS) does this.
370 (unless (eq *boot-state* 'complete)
371 (%set-class-type-translation class name))
374 (defun frob-ensure-class-args (args)
375 (let (metaclass metaclassp reversed-plist)
376 (flet ((frob-superclass (s)
379 ((legal-class-name-p s)
380 (or (find-class s nil)
381 (ensure-class s :metaclass 'forward-referenced-class)))
382 (t (error "Not a class or a legal class name: ~S." s)))))
383 (doplist (key val) args
384 (cond ((eq key :metaclass)
386 (setf metaclass val metaclassp key)))
388 (when (eq key :direct-superclasses)
389 (setf val (mapcar #'frob-superclass val)))
390 (setf reversed-plist (list* val key reversed-plist)))))
391 (values (cond (metaclassp
392 (if (classp metaclass)
394 (find-class metaclass)))
395 (t *the-class-standard-class*))
396 (nreverse reversed-plist)))))
398 (defun call-initfun (fun slotd safe)
399 (declare (function fun))
400 (let ((value (funcall fun)))
402 (let ((typecheck (slot-definition-type-check-function slotd)))
404 (funcall (the function typecheck) value))))
407 (defmethod shared-initialize :after
408 ((class std-class) slot-names &key
409 (direct-superclasses nil direct-superclasses-p)
410 (direct-slots nil direct-slots-p)
411 (direct-default-initargs nil direct-default-initargs-p)
413 (cond (direct-superclasses-p
414 (setq direct-superclasses
415 (or direct-superclasses
416 (list (if (funcallable-standard-class-p class)
417 *the-class-funcallable-standard-object*
418 *the-class-standard-object*))))
419 (dolist (superclass direct-superclasses)
420 (unless (validate-superclass class superclass)
421 (error "~@<The class ~S was specified as a ~
422 super-class of the class ~S, ~
423 but the meta-classes ~S and ~S are incompatible. ~
424 Define a method for ~S to avoid this error.~@:>"
425 superclass class (class-of superclass) (class-of class)
426 'validate-superclass)))
427 (setf (slot-value class 'direct-superclasses) direct-superclasses))
429 (setq direct-superclasses (slot-value class 'direct-superclasses))))
432 (setf (slot-value class 'direct-slots)
433 (mapcar (lambda (pl) (make-direct-slotd class pl))
435 (slot-value class 'direct-slots)))
436 (if direct-default-initargs-p
437 (setf (plist-value class 'direct-default-initargs)
438 direct-default-initargs)
439 (setq direct-default-initargs
440 (plist-value class 'direct-default-initargs)))
441 (setf (plist-value class 'class-slot-cells)
442 (let ((old-class-slot-cells (plist-value class 'class-slot-cells))
443 (safe (safe-p class))
445 (dolist (dslotd direct-slots)
446 (when (eq :class (slot-definition-allocation dslotd))
448 (let* ((name (slot-definition-name dslotd))
449 (old (assoc name old-class-slot-cells)))
452 (member name slot-names :test #'eq))
453 (let* ((initfunction (slot-definition-initfunction dslotd))
456 (call-initfun initfunction dslotd safe)
458 (push (cons name value) collect))
459 (push old collect)))))
461 (add-direct-subclasses class direct-superclasses)
462 (if (class-finalized-p class)
463 ;; required by AMOP, "Reinitialization of Class Metaobjects"
464 (finalize-inheritance class)
465 (update-class class nil))
466 (add-slot-accessors class direct-slots definition-source)
467 (make-preliminary-layout class))
469 (defmethod shared-initialize :after ((class forward-referenced-class)
470 slot-names &key &allow-other-keys)
471 (declare (ignore slot-names))
472 (make-preliminary-layout class))
474 (defvar *allow-forward-referenced-classes-in-cpl-p* nil)
476 ;;; Give CLASS a preliminary layout if it doesn't have one already, to
477 ;;; make it known to the type system.
478 (defun make-preliminary-layout (class)
479 (flet ((compute-preliminary-cpl (root)
480 (let ((*allow-forward-referenced-classes-in-cpl-p* t))
481 (compute-class-precedence-list root))))
483 (without-package-locks
484 (unless (class-finalized-p class)
485 (let ((name (class-name class)))
486 ;; KLUDGE: This is fairly horrible. We need to make a
487 ;; full-fledged CLASSOID here, not just tell the compiler that
488 ;; some class is forthcoming, because there are legitimate
489 ;; questions one can ask of the type system, implemented in
490 ;; terms of CLASSOIDs, involving forward-referenced classes. So.
491 (let ((layout (make-wrapper 0 class)))
492 (setf (slot-value class 'wrapper) layout)
493 (let ((cpl (compute-preliminary-cpl class)))
494 (setf (layout-inherits layout)
495 (order-layout-inherits
496 (map 'simple-vector #'class-wrapper
497 (reverse (rest cpl))))))
498 (register-layout layout :invalidate t)
499 (%set-class-type-translation class (layout-classoid layout)))))
500 (mapc #'make-preliminary-layout (class-direct-subclasses class))))))
503 (defmethod shared-initialize :before ((class class) slot-names &key name)
504 (declare (ignore slot-names name))
505 ;; FIXME: Could this just be CLASS instead of `(CLASS ,CLASS)? If not,
506 ;; why not? (See also similar expression in !BOOTSTRAP-INITIALIZE-CLASS.)
507 (setf (slot-value class '%type) `(class ,class))
508 (setf (slot-value class 'class-eq-specializer)
509 (make-instance 'class-eq-specializer :class class)))
511 (defmethod reinitialize-instance :before ((class slot-class) &key direct-superclasses)
512 (dolist (old-super (set-difference (class-direct-superclasses class) direct-superclasses))
513 (remove-direct-subclass old-super class))
514 (remove-slot-accessors class (class-direct-slots class)))
516 (defmethod reinitialize-instance :after ((class slot-class)
519 (map-dependents class
521 (apply #'update-dependent class dependent initargs))))
523 (defmethod reinitialize-instance :after ((class condition-class) &key)
524 (let* ((name (class-name class))
525 (classoid (find-classoid name))
526 (slots (condition-classoid-slots classoid)))
527 ;; to balance the REMOVE-SLOT-ACCESSORS call in
528 ;; REINITIALIZE-INSTANCE :BEFORE (SLOT-CLASS).
530 (let ((slot-name (condition-slot-name slot)))
531 (dolist (reader (condition-slot-readers slot))
532 ;; FIXME: see comment in SHARED-INITIALIZE :AFTER
533 ;; (CONDITION-CLASS T), below. -- CSR, 2005-11-18
534 (sb-kernel::install-condition-slot-reader reader name slot-name))
535 (dolist (writer (condition-slot-writers slot))
536 (sb-kernel::install-condition-slot-writer writer name slot-name))))))
538 (defmethod shared-initialize :after ((class condition-class) slot-names
539 &key direct-slots direct-superclasses)
540 (declare (ignore slot-names))
541 (let ((classoid (find-classoid (slot-value class 'name))))
542 (with-slots (wrapper %class-precedence-list cpl-available-p
543 prototype (direct-supers direct-superclasses))
545 (setf (slot-value class 'direct-slots)
546 (mapcar (lambda (pl) (make-direct-slotd class pl))
548 (setf (slot-value class 'finalized-p) t)
549 (setf (classoid-pcl-class classoid) class)
550 (setq direct-supers direct-superclasses)
551 (setq wrapper (classoid-layout classoid))
552 (setq %class-precedence-list (compute-class-precedence-list class))
553 (setq cpl-available-p t)
554 (add-direct-subclasses class direct-superclasses)
555 (let ((slots (compute-slots class)))
556 (setf (slot-value class 'slots) slots)
557 (setf (layout-slot-table wrapper) (make-slot-table class slots)))))
558 ;; Comment from Gerd's PCL, 2003-05-15:
560 ;; We don't ADD-SLOT-ACCESSORS here because we don't want to
561 ;; override condition accessors with generic functions. We do this
564 ;; ??? What does the above comment mean and why is it a good idea?
565 ;; CMUCL (which still as of 2005-11-18 uses this code and has this
566 ;; comment) loses slot information in its condition classes:
567 ;; DIRECT-SLOTS is always NIL. We have the right information, so we
568 ;; remove slot accessors but never put them back. I've added a
569 ;; REINITIALIZE-INSTANCE :AFTER (CONDITION-CLASS) method, but what
570 ;; was meant to happen? -- CSR, 2005-11-18
573 (defmethod direct-slot-definition-class ((class condition-class)
575 (declare (ignore initargs))
576 (find-class 'condition-direct-slot-definition))
578 (defmethod effective-slot-definition-class ((class condition-class)
580 (declare (ignore initargs))
581 (find-class 'condition-effective-slot-definition))
583 (defmethod finalize-inheritance ((class condition-class))
584 (aver (slot-value class 'finalized-p))
587 (defmethod compute-effective-slot-definition
588 ((class condition-class) slot-name dslotds)
589 (let ((slotd (call-next-method)))
590 (setf (slot-definition-reader-function slotd)
592 (handler-case (condition-reader-function x slot-name)
593 ;; FIXME: FIND-SLOT-DEFAULT throws an error if the slot
594 ;; is unbound; maybe it should be a CELL-ERROR of some
596 (error () (values (slot-unbound class x slot-name))))))
597 (setf (slot-definition-writer-function slotd)
599 (condition-writer-function x v slot-name)))
600 (setf (slot-definition-boundp-function slotd)
602 (multiple-value-bind (v c)
603 (ignore-errors (condition-reader-function x slot-name))
608 (defmethod compute-slots ((class condition-class))
609 (mapcan (lambda (superclass)
610 (mapcar (lambda (dslotd)
611 (compute-effective-slot-definition
612 class (slot-definition-name dslotd) (list dslotd)))
613 (class-direct-slots superclass)))
614 (reverse (slot-value class '%class-precedence-list))))
616 (defmethod compute-slots :around ((class condition-class))
617 (let ((eslotds (call-next-method)))
618 (mapc #'initialize-internal-slot-functions eslotds)
621 (defmethod shared-initialize :after
622 ((slotd structure-slot-definition) slot-names &key
623 (allocation :instance) allocation-class)
624 (declare (ignore slot-names allocation-class))
625 (unless (eq allocation :instance)
626 (error "Structure slots must have :INSTANCE allocation.")))
628 (defun make-structure-class-defstruct-form (name direct-slots include)
629 (let* ((conc-name (format-symbol *package* "~S structure class " name))
630 (constructor (format-symbol *package* "~Aconstructor" conc-name))
631 (defstruct `(defstruct (,name
633 `((:include ,(class-name include))))
635 (:conc-name ,conc-name)
636 (:constructor ,constructor ())
638 ,@(mapcar (lambda (slot)
639 `(,(slot-definition-name slot)
642 (reader-names (mapcar (lambda (slotd)
643 (list 'slot-accessor name
644 (slot-definition-name slotd)
647 (writer-names (mapcar (lambda (slotd)
648 (list 'slot-accessor name
649 (slot-definition-name slotd)
653 (mapcar (lambda (slotd reader-name)
655 (slot-definition-defstruct-accessor-symbol
657 `(defun ,reader-name (obj)
658 (declare (type ,name obj))
660 direct-slots reader-names))
662 (mapcar (lambda (slotd writer-name)
664 (slot-definition-defstruct-accessor-symbol
666 `(defun ,writer-name (nv obj)
667 (declare (type ,name obj))
668 (setf (,accessor obj) nv))))
669 direct-slots writer-names))
673 ,@readers-init ,@writers-init
675 (values defstruct-form constructor reader-names writer-names)))
677 (defun make-defstruct-allocation-function (name)
678 ;; FIXME: Why don't we go class->layout->info == dd
679 (let ((dd (find-defstruct-description name)))
682 (%make-structure-instance-allocator dd nil))
683 (funcallable-structure
684 (%make-funcallable-structure-instance-allocator dd nil)))))
686 (defmethod shared-initialize :after
687 ((class structure-class) slot-names &key
688 (direct-superclasses nil direct-superclasses-p)
689 (direct-slots nil direct-slots-p)
690 direct-default-initargs
692 (declare (ignore slot-names direct-default-initargs))
693 (if direct-superclasses-p
694 (setf (slot-value class 'direct-superclasses)
695 (or direct-superclasses
696 (setq direct-superclasses
697 (and (not (eq (slot-value class 'name) 'structure-object))
698 (list *the-class-structure-object*)))))
699 (setq direct-superclasses (slot-value class 'direct-superclasses)))
700 (let* ((name (slot-value class 'name))
701 (from-defclass-p (slot-value class 'from-defclass-p))
702 (defstruct-p (or from-defclass-p (not (structure-type-p name)))))
704 (setf (slot-value class 'direct-slots)
708 (let* ((slot-name (getf pl :name))
710 (format-symbol *package*
711 "~S structure class ~A"
713 (setq pl (list* :defstruct-accessor-symbol
715 (make-direct-slotd class pl))
717 (setq direct-slots (slot-value class 'direct-slots)))
719 (let ((include (car (slot-value class 'direct-superclasses))))
720 (multiple-value-bind (defstruct-form constructor reader-names writer-names)
721 (make-structure-class-defstruct-form name direct-slots include)
722 (unless (structure-type-p name) (eval defstruct-form))
723 (mapc (lambda (dslotd reader-name writer-name)
724 (let* ((reader (gdefinition reader-name))
725 (writer (when (fboundp writer-name)
726 (gdefinition writer-name))))
727 (setf (slot-value dslotd 'internal-reader-function)
729 (setf (slot-value dslotd 'internal-writer-function)
731 direct-slots reader-names writer-names)
732 (setf (slot-value class 'defstruct-form) defstruct-form)
733 (setf (slot-value class 'defstruct-constructor) constructor)))
734 (setf (slot-value class 'defstruct-constructor)
735 ;; KLUDGE: not class; in fixup.lisp, can't access slots
736 ;; outside methods yet.
737 (make-defstruct-allocation-function name)))
738 (add-direct-subclasses class direct-superclasses)
739 (setf (slot-value class '%class-precedence-list)
740 (compute-class-precedence-list class))
741 (setf (slot-value class 'cpl-available-p) t)
742 (let ((slots (compute-slots class)))
743 (setf (slot-value class 'slots) slots)
744 (let* ((lclass (find-classoid (slot-value class 'name)))
745 (layout (classoid-layout lclass)))
746 (setf (classoid-pcl-class lclass) class)
747 (setf (slot-value class 'wrapper) layout)
748 (setf (layout-slot-table layout) (make-slot-table class slots))))
749 (setf (slot-value class 'finalized-p) t)
750 (add-slot-accessors class direct-slots definition-source)))
752 (defmethod direct-slot-definition-class ((class structure-class) &rest initargs)
753 (declare (ignore initargs))
754 (find-class 'structure-direct-slot-definition))
756 (defmethod finalize-inheritance ((class structure-class))
757 nil) ; always finalized
759 (defun add-slot-accessors (class dslotds &optional source-location)
760 (fix-slot-accessors class dslotds 'add source-location))
762 (defun remove-slot-accessors (class dslotds)
763 (fix-slot-accessors class dslotds 'remove))
765 (defun fix-slot-accessors (class dslotds add/remove &optional source-location)
766 (flet ((fix (gfspec name r/w doc)
767 (let ((gf (cond ((eq add/remove 'add)
768 (or (find-generic-function gfspec nil)
769 (ensure-generic-function
770 gfspec :lambda-list (case r/w
772 (w '(new-value object))))))
774 (find-generic-function gfspec nil)))))
777 (r (if (eq add/remove 'add)
778 (add-reader-method class gf name doc source-location)
779 (remove-reader-method class gf)))
780 (w (if (eq add/remove 'add)
781 (add-writer-method class gf name doc source-location)
782 (remove-writer-method class gf))))))))
783 (dolist (dslotd dslotds)
784 (let ((slot-name (slot-definition-name dslotd))
785 (slot-doc (%slot-definition-documentation dslotd)))
786 (dolist (r (slot-definition-readers dslotd))
787 (fix r slot-name 'r slot-doc))
788 (dolist (w (slot-definition-writers dslotd))
789 (fix w slot-name 'w slot-doc))))))
791 (defun add-direct-subclasses (class supers)
792 (dolist (super supers)
793 (unless (memq class (class-direct-subclasses class))
794 (add-direct-subclass super class))))
796 (defmethod finalize-inheritance ((class std-class))
797 (update-class class t))
799 (defmethod finalize-inheritance ((class forward-referenced-class))
800 ;; FIXME: should we not be thinking a bit about what kinds of error
801 ;; we're throwing? Maybe we need a clos-error type to mix in? Or
802 ;; possibly a forward-referenced-class-error, though that's
803 ;; difficult given e.g. class precedence list calculations...
805 "~@<FINALIZE-INHERITANCE was called on a forward referenced class:~
810 (defun class-has-a-forward-referenced-superclass-p (class)
811 (or (forward-referenced-class-p class)
812 (some #'class-has-a-forward-referenced-superclass-p
813 (class-direct-superclasses class))))
815 ;;; This is called by :after shared-initialize whenever a class is initialized
816 ;;; or reinitialized. The class may or may not be finalized.
817 (defun update-class (class finalizep)
818 (without-package-locks
820 (when (or finalizep (class-finalized-p class))
821 (%update-cpl class (compute-class-precedence-list class))
822 ;; This invocation of UPDATE-SLOTS, in practice, finalizes the
824 (%update-slots class (compute-slots class))
825 (update-gfs-of-class class)
826 (setf (plist-value class 'default-initargs) (compute-default-initargs class))
827 (update-ctors 'finalize-inheritance :class class))
828 (dolist (sub (class-direct-subclasses class))
829 (update-class sub nil)))))
831 (define-condition cpl-protocol-violation (reference-condition error)
832 ((class :initarg :class :reader cpl-protocol-violation-class)
833 (cpl :initarg :cpl :reader cpl-protocol-violation-cpl))
834 (:default-initargs :references (list '(:sbcl :node "Metaobject Protocol")))
837 (format s "~@<Protocol violation: the ~S class ~S ~
838 ~:[has~;does not have~] the class ~S in its ~
839 class precedence list: ~S.~@:>"
840 (class-name (class-of (cpl-protocol-violation-class c)))
841 (cpl-protocol-violation-class c)
842 (eq (class-of (cpl-protocol-violation-class c))
843 *the-class-funcallable-standard-class*)
844 (find-class 'function)
845 (cpl-protocol-violation-cpl c)))))
847 (defun %update-cpl (class cpl)
848 (when (eq (class-of class) *the-class-standard-class*)
849 (when (find (find-class 'function) cpl)
850 (error 'cpl-protocol-violation :class class :cpl cpl)))
851 (when (eq (class-of class) *the-class-funcallable-standard-class*)
852 (unless (find (find-class 'function) cpl)
853 (error 'cpl-protocol-violation :class class :cpl cpl)))
854 (if (class-finalized-p class)
855 (unless (and (equal (class-precedence-list class) cpl)
857 (when (position :class (class-direct-slots c)
858 :key #'slot-definition-allocation)
860 ;; comment from the old CMU CL sources:
861 ;; Need to have the cpl setup before %update-lisp-class-layout
862 ;; is called on CMU CL.
863 (setf (slot-value class '%class-precedence-list) cpl)
864 (setf (slot-value class 'cpl-available-p) t)
865 (%force-cache-flushes class))
867 (setf (slot-value class '%class-precedence-list) cpl)
868 (setf (slot-value class 'cpl-available-p) t)))
869 (update-class-can-precede-p cpl))
871 (defun update-class-can-precede-p (cpl)
873 (let ((first (car cpl)))
874 (dolist (c (cdr cpl))
875 (pushnew c (slot-value first 'can-precede-list) :test #'eq)))
876 (update-class-can-precede-p (cdr cpl))))
878 (defun class-can-precede-p (class1 class2)
879 (member class2 (class-can-precede-list class1) :test #'eq))
881 (defun %update-slots (class eslotds)
882 (let ((instance-slots ())
884 (dolist (eslotd eslotds)
885 (let ((alloc (slot-definition-allocation eslotd)))
887 (:instance (push eslotd instance-slots))
888 (:class (push eslotd class-slots)))))
890 ;; If there is a change in the shape of the instances then the
891 ;; old class is now obsolete.
892 (let* ((nlayout (mapcar #'slot-definition-name
893 (sort instance-slots #'<
894 :key #'slot-definition-location)))
895 (nslots (length nlayout))
896 (nwrapper-class-slots (compute-class-slots class-slots))
897 (owrapper (when (class-finalized-p class)
898 (class-wrapper class)))
899 (olayout (when owrapper
900 (wrapper-instance-slots-layout owrapper)))
901 (owrapper-class-slots (and owrapper (wrapper-class-slots owrapper)))
903 (cond ((null owrapper)
904 (make-wrapper nslots class))
905 ((and (equal nlayout olayout)
907 (loop for o in owrapper-class-slots
908 for n in nwrapper-class-slots
909 do (unless (eq (car o) (car n)) (return t)))))
912 ;; This will initialize the new wrapper to have the
913 ;; same state as the old wrapper. We will then have
914 ;; to change that. This may seem like wasted work
915 ;; (and it is), but the spec requires that we call
916 ;; MAKE-INSTANCES-OBSOLETE.
917 (make-instances-obsolete class)
918 (class-wrapper class)))))
920 (%update-lisp-class-layout class nwrapper)
921 (setf (slot-value class 'slots) eslotds
922 (wrapper-slot-table nwrapper) (make-slot-table class eslotds)
923 (wrapper-instance-slots-layout nwrapper) nlayout
924 (wrapper-class-slots nwrapper) nwrapper-class-slots
925 (wrapper-length nwrapper) nslots
926 (slot-value class 'wrapper) nwrapper)
927 (do* ((slots (slot-value class 'slots) (cdr slots))
932 "~@<slot names with the same SYMBOL-NAME but ~
933 different SYMBOL-PACKAGE (possible package problem) ~
934 for class ~S:~4I~@:_~<~@{~S~^~:@_~}~:>~@:>"
936 (let* ((slot (car slots))
937 (oslots (remove (slot-definition-name slot) (cdr slots)
939 :key #'slot-definition-name)))
941 (pushnew (cons (slot-definition-name slot)
942 (mapcar #'slot-definition-name oslots))
944 :test #'string= :key #'car))))
945 (setf (slot-value class 'finalized-p) t)
946 (unless (eq owrapper nwrapper)
947 (maybe-update-standard-slot-locations class)))))
949 (defun compute-class-slots (eslotds)
951 (dolist (eslotd eslotds (nreverse collect))
952 (let ((cell (assoc (slot-definition-name eslotd)
954 (slot-definition-allocation-class eslotd)))))
956 (push cell collect)))))
958 (defun update-gf-dfun (class gf)
959 (let ((*new-class* class)
960 (arg-info (gf-arg-info gf)))
962 ((special-case-for-compute-discriminating-function-p gf))
963 ((gf-precompute-dfun-and-emf-p arg-info)
964 (multiple-value-bind (dfun cache info) (make-final-dfun-internal gf)
965 (update-dfun gf dfun cache info))))))
967 (defun update-gfs-of-class (class)
968 (when (and (class-finalized-p class)
969 (let ((cpl (class-precedence-list class)))
970 (or (member *the-class-slot-class* cpl :test #'eq)
971 (member *the-class-standard-effective-slot-definition*
973 (let ((gf-table (make-hash-table :test 'eq)))
974 (labels ((collect-gfs (class)
975 (dolist (gf (specializer-direct-generic-functions class))
976 (setf (gethash gf gf-table) t))
977 (mapc #'collect-gfs (class-direct-superclasses class))))
979 (maphash (lambda (gf ignore)
980 (declare (ignore ignore))
981 (update-gf-dfun class gf))
984 (defmethod compute-default-initargs ((class slot-class))
985 (let ((initargs (loop for c in (class-precedence-list class)
986 append (class-direct-default-initargs c))))
987 (delete-duplicates initargs :test #'eq :key #'car :from-end t)))
989 ;;;; protocols for constructing direct and effective slot definitions
991 (defmethod direct-slot-definition-class ((class std-class) &rest initargs)
992 (declare (ignore initargs))
993 (find-class 'standard-direct-slot-definition))
995 (defun make-direct-slotd (class initargs)
996 (apply #'make-instance
997 (apply #'direct-slot-definition-class class initargs)
1001 ;;; I (CSR) am not sure, but I believe that the particular order of
1002 ;;; slots is quite important: it is ideal to attempt to have a
1003 ;;; constant slot location for the same notional slots as much as
1004 ;;; possible, so that clever discriminating functions (ONE-INDEX et
1005 ;;; al.) have a chance of working. The below at least walks through
1006 ;;; the slots predictably, but maybe it would be good to compute some
1007 ;;; kind of optimal slot layout by looking at locations of slots in
1009 (defun std-compute-slots (class)
1010 ;; As specified, we must call COMPUTE-EFFECTIVE-SLOT-DEFINITION once
1011 ;; for each different slot name we find in our superclasses. Each
1012 ;; call receives the class and a list of the dslotds with that name.
1013 ;; The list is in most-specific-first order.
1014 (let ((name-dslotds-alist ()))
1015 (dolist (c (reverse (class-precedence-list class)))
1016 (dolist (slot (class-direct-slots c))
1017 (let* ((name (slot-definition-name slot))
1018 (entry (assq name name-dslotds-alist)))
1020 (push slot (cdr entry))
1021 (push (list name slot) name-dslotds-alist)))))
1022 (mapcar (lambda (direct)
1023 (compute-effective-slot-definition class
1026 (nreverse name-dslotds-alist))))
1028 (defmethod compute-slots ((class standard-class))
1029 (std-compute-slots class))
1030 (defmethod compute-slots ((class funcallable-standard-class))
1031 (std-compute-slots class))
1033 (defun std-compute-slots-around (class eslotds)
1035 (safe (safe-p class)))
1036 (dolist (eslotd eslotds eslotds)
1037 (setf (slot-definition-location eslotd)
1038 (case (slot-definition-allocation eslotd)
1042 (let* ((name (slot-definition-name eslotd))
1045 (slot-definition-allocation-class eslotd)
1046 ;; we get here if the user adds an extra slot
1048 (setf (slot-definition-allocation-class eslotd)
1050 ;; which raises the question of what we should
1051 ;; do if we find that said user has added a slot
1052 ;; with the same name as another slot...
1053 (cell (or (assq name (class-slot-cells from-class))
1054 (let ((c (cons name +slot-unbound+)))
1055 (push c (class-slot-cells from-class))
1058 (if (eq +slot-unbound+ (cdr cell))
1059 ;; We may have inherited an initfunction FIXME: Is this
1060 ;; really right? Is the initialization in
1061 ;; SHARED-INITIALIZE (STD-CLASS) not enough?
1062 (let ((initfun (slot-definition-initfunction eslotd)))
1064 (rplacd cell (call-initfun initfun eslotd safe))
1067 (unless (slot-definition-class eslotd)
1068 (setf (slot-definition-class eslotd) class))
1069 (initialize-internal-slot-functions eslotd))))
1071 (defmethod compute-slots :around ((class standard-class))
1072 (let ((eslotds (call-next-method)))
1073 (std-compute-slots-around class eslotds)))
1074 (defmethod compute-slots :around ((class funcallable-standard-class))
1075 (let ((eslotds (call-next-method)))
1076 (std-compute-slots-around class eslotds)))
1078 (defmethod compute-slots ((class structure-class))
1079 (mapcan (lambda (superclass)
1080 (mapcar (lambda (dslotd)
1081 (compute-effective-slot-definition
1083 (slot-definition-name dslotd)
1085 (class-direct-slots superclass)))
1086 (reverse (slot-value class '%class-precedence-list))))
1088 (defmethod compute-slots :around ((class structure-class))
1089 (let ((eslotds (call-next-method)))
1090 (mapc #'initialize-internal-slot-functions eslotds)
1093 (defmethod compute-effective-slot-definition ((class slot-class) name dslotds)
1094 (declare (ignore name))
1095 (let* ((initargs (compute-effective-slot-definition-initargs class dslotds))
1096 (class (apply #'effective-slot-definition-class class initargs)))
1097 (apply #'make-instance class initargs)))
1099 (defmethod effective-slot-definition-class ((class std-class) &rest initargs)
1100 (declare (ignore initargs))
1101 (find-class 'standard-effective-slot-definition))
1103 (defmethod effective-slot-definition-class ((class structure-class) &rest initargs)
1104 (declare (ignore initargs))
1105 (find-class 'structure-effective-slot-definition))
1107 (defmethod compute-effective-slot-definition-initargs
1108 ((class slot-class) direct-slotds)
1114 (allocation-class nil)
1116 (type-check-function nil)
1118 (documentationp nil)
1123 (dolist (slotd direct-slotds)
1126 (setq name (slot-definition-name slotd)
1129 (awhen (slot-definition-initfunction slotd)
1130 (setq initform (slot-definition-initform slotd)
1133 (unless documentationp
1134 (awhen (%slot-definition-documentation slotd)
1135 (setq documentation it
1138 (setq allocation (slot-definition-allocation slotd)
1139 allocation-class (slot-definition-class slotd)
1141 (setq initargs (append (slot-definition-initargs slotd) initargs))
1142 (let ((fun (slot-definition-type-check-function slotd)))
1144 (setf type-check-function
1145 (if type-check-function
1146 (let ((old-function type-check-function))
1147 (declare (function old-function fun))
1149 (funcall old-function value)
1150 (funcall fun value)))
1152 (let ((slotd-type (slot-definition-type slotd)))
1154 ((eq type t) slotd-type)
1155 ;; This pairwise type intersection is perhaps a
1156 ;; little inefficient and inelegant, but it's
1157 ;; unlikely to lie on the critical path. Shout
1158 ;; if I'm wrong. -- CSR, 2005-11-24
1160 (specifier-type `(and ,type ,slotd-type)))))))))
1163 :initfunction initfunction
1165 :allocation allocation
1166 :allocation-class allocation-class
1168 'type-check-function type-check-function
1170 :documentation documentation)))
1172 (defmethod compute-effective-slot-definition-initargs :around
1173 ((class structure-class) direct-slotds)
1174 (let ((slotd (car direct-slotds)))
1175 (list* :defstruct-accessor-symbol
1176 (slot-definition-defstruct-accessor-symbol slotd)
1177 :internal-reader-function
1178 (slot-definition-internal-reader-function slotd)
1179 :internal-writer-function
1180 (slot-definition-internal-writer-function slotd)
1181 (call-next-method))))
1183 ;;; NOTE: For bootstrapping considerations, these can't use MAKE-INSTANCE
1184 ;;; to make the method object. They have to use make-a-method which
1185 ;;; is a specially bootstrapped mechanism for making standard methods.
1186 (defmethod reader-method-class ((class slot-class) direct-slot &rest initargs)
1187 (declare (ignore direct-slot initargs))
1188 (find-class 'standard-reader-method))
1190 (defmethod add-reader-method ((class slot-class) generic-function slot-name slot-documentation source-location)
1191 (add-method generic-function
1192 (make-a-method 'standard-reader-method
1194 (list (or (class-name class) 'object))
1196 (make-reader-method-function class slot-name)
1197 (or slot-documentation "automatically generated reader method")
1198 :slot-name slot-name
1200 :method-class-function #'reader-method-class
1201 :definition-source source-location)))
1203 (defmethod writer-method-class ((class slot-class) direct-slot &rest initargs)
1204 (declare (ignore direct-slot initargs))
1205 (find-class 'standard-writer-method))
1207 (defmethod add-writer-method ((class slot-class) generic-function slot-name slot-documentation source-location)
1208 (add-method generic-function
1209 (make-a-method 'standard-writer-method
1211 (list 'new-value (or (class-name class) 'object))
1212 (list *the-class-t* class)
1213 (make-writer-method-function class slot-name)
1214 (or slot-documentation "automatically generated writer method")
1215 :slot-name slot-name
1217 :method-class-function #'writer-method-class
1218 :definition-source source-location)))
1220 (defmethod add-boundp-method ((class slot-class) generic-function slot-name slot-documentation source-location)
1221 (add-method generic-function
1222 (make-a-method (constantly (find-class 'standard-boundp-method))
1225 (list (or (class-name class) 'object))
1227 (make-boundp-method-function class slot-name)
1228 (or slot-documentation "automatically generated boundp method")
1229 :slot-name slot-name
1230 :definition-source source-location)))
1232 (defmethod remove-reader-method ((class slot-class) generic-function)
1233 (let ((method (get-method generic-function () (list class) nil)))
1234 (when method (remove-method generic-function method))))
1236 (defmethod remove-writer-method ((class slot-class) generic-function)
1238 (get-method generic-function () (list *the-class-t* class) nil)))
1239 (when method (remove-method generic-function method))))
1241 (defmethod remove-boundp-method ((class slot-class) generic-function)
1242 (let ((method (get-method generic-function () (list class) nil)))
1243 (when method (remove-method generic-function method))))
1245 ;;; MAKE-READER-METHOD-FUNCTION and MAKE-WRITER-METHOD-FUNCTION
1246 ;;; function are NOT part of the standard protocol. They are however
1247 ;;; useful; PCL makes use of them internally and documents them for
1248 ;;; PCL users. (FIXME: but SBCL certainly doesn't)
1250 ;;; *** This needs work to make type testing by the writer functions which
1251 ;;; *** do type testing faster. The idea would be to have one constructor
1252 ;;; *** for each possible type test.
1254 ;;; *** There is a subtle bug here which is going to have to be fixed.
1255 ;;; *** Namely, the simplistic use of the template has to be fixed. We
1256 ;;; *** have to give the OPTIMIZE-SLOT-VALUE method the user might have
1257 ;;; *** defined for this metaclass a chance to run.
1259 (defmethod make-reader-method-function ((class slot-class) slot-name)
1260 (make-std-reader-method-function class slot-name))
1262 (defmethod make-writer-method-function ((class slot-class) slot-name)
1263 (make-std-writer-method-function class slot-name))
1265 (defmethod make-boundp-method-function ((class slot-class) slot-name)
1266 (make-std-boundp-method-function class slot-name))
1268 (defmethod compatible-meta-class-change-p (class proto-new-class)
1269 (eq (class-of class) (class-of proto-new-class)))
1271 (defmethod validate-superclass ((class class) (superclass class))
1272 (or (eq superclass *the-class-t*)
1273 (eq (class-of class) (class-of superclass))
1274 (and (eq (class-of superclass) *the-class-standard-class*)
1275 (eq (class-of class) *the-class-funcallable-standard-class*))
1276 (and (eq (class-of superclass) *the-class-funcallable-standard-class*)
1277 (eq (class-of class) *the-class-standard-class*))))
1279 ;;; What this does depends on which of the four possible values of
1280 ;;; LAYOUT-INVALID the PCL wrapper has; the simplest case is when it
1281 ;;; is (:FLUSH <wrapper>) or (:OBSOLETE <wrapper>), when there is
1282 ;;; nothing to do, as the new wrapper has already been created. If
1283 ;;; LAYOUT-INVALID returns NIL, then we invalidate it (setting it to
1284 ;;; (:FLUSH <wrapper>); UPDATE-SLOTS later gets to choose whether or
1285 ;;; not to "upgrade" this to (:OBSOLETE <wrapper>).
1287 ;;; This leaves the case where LAYOUT-INVALID returns T, which happens
1288 ;;; when REGISTER-LAYOUT has invalidated a superclass of CLASS (which
1289 ;;; invalidated all the subclasses in SB-KERNEL land). Again, here we
1290 ;;; must flush the caches and allow UPDATE-SLOTS to decide whether to
1291 ;;; obsolete the wrapper.
1293 ;;; FIXME: either here or in INVALID-WRAPPER-P looks like a good place
1294 ;;; for (AVER (NOT (EQ (LAYOUT-INVALID OWRAPPER)
1295 ;;; :UNINITIALIZED)))
1297 ;;; Thanks to Gerd Moellmann for the explanation. -- CSR, 2002-10-29
1298 (defun %force-cache-flushes (class)
1299 (let* ((owrapper (class-wrapper class)))
1300 ;; We only need to do something if the wrapper is still valid. If
1301 ;; the wrapper isn't valid, state will be FLUSH or OBSOLETE, and
1302 ;; both of those will already be doing what we want. In
1303 ;; particular, we must be sure we never change an OBSOLETE into a
1304 ;; FLUSH since OBSOLETE means do what FLUSH does and then some.
1305 (when (or (not (invalid-wrapper-p owrapper))
1306 ;; KLUDGE: despite the observations above, this remains
1307 ;; a violation of locality or what might be considered
1308 ;; good style. There has to be a better way! -- CSR,
1310 (eq (layout-invalid owrapper) t))
1311 (let ((nwrapper (make-wrapper (layout-length owrapper)
1313 (setf (wrapper-instance-slots-layout nwrapper)
1314 (wrapper-instance-slots-layout owrapper))
1315 (setf (wrapper-class-slots nwrapper)
1316 (wrapper-class-slots owrapper))
1317 (setf (wrapper-slot-table nwrapper)
1318 (wrapper-slot-table owrapper))
1319 (%update-lisp-class-layout class nwrapper)
1320 (setf (slot-value class 'wrapper) nwrapper)
1321 ;; Use :OBSOLETE instead of :FLUSH if any superclass has
1323 (if (find-if (lambda (x)
1324 (and (consp x) (eq :obsolete (car x))))
1325 (layout-inherits owrapper)
1326 :key #'layout-invalid)
1327 (%invalidate-wrapper owrapper :obsolete nwrapper)
1328 (%invalidate-wrapper owrapper :flush nwrapper))))))
1330 ;;; MAKE-INSTANCES-OBSOLETE can be called by user code. It will cause
1331 ;;; the next access to the instance (as defined in 88-002R) to trap
1332 ;;; through the UPDATE-INSTANCE-FOR-REDEFINED-CLASS mechanism.
1333 (defmethod make-instances-obsolete ((class std-class))
1335 (let* ((owrapper (class-wrapper class))
1336 (nwrapper (make-wrapper (layout-length owrapper)
1338 (unless (class-finalized-p class)
1339 (if (class-has-a-forward-referenced-superclass-p class)
1340 (return-from make-instances-obsolete class)
1341 (%update-cpl class (compute-class-precedence-list class))))
1342 (setf (wrapper-instance-slots-layout nwrapper)
1343 (wrapper-instance-slots-layout owrapper))
1344 (setf (wrapper-class-slots nwrapper)
1345 (wrapper-class-slots owrapper))
1346 (setf (wrapper-slot-table nwrapper)
1347 (wrapper-slot-table owrapper))
1348 (%update-lisp-class-layout class nwrapper)
1349 (setf (slot-value class 'wrapper) nwrapper)
1350 (%invalidate-wrapper owrapper :obsolete nwrapper)
1353 (defmethod make-instances-obsolete ((class symbol))
1354 (make-instances-obsolete (find-class class))
1355 ;; ANSI wants the class name when called with a symbol.
1358 ;;; OBSOLETE-INSTANCE-TRAP is the internal trap that is called when we
1359 ;;; see an obsolete instance. The times when it is called are:
1360 ;;; - when the instance is involved in method lookup
1361 ;;; - when attempting to access a slot of an instance
1363 ;;; It is not called by class-of, wrapper-of, or any of the low-level
1364 ;;; instance access macros.
1366 ;;; Of course these times when it is called are an internal
1367 ;;; implementation detail of PCL and are not part of the documented
1368 ;;; description of when the obsolete instance update happens. The
1369 ;;; documented description is as it appears in 88-002R.
1371 ;;; This has to return the new wrapper, so it counts on all the
1372 ;;; methods on obsolete-instance-trap-internal to return the new
1373 ;;; wrapper. It also does a little internal error checking to make
1374 ;;; sure that the traps are only happening when they should, and that
1375 ;;; the trap methods are computing appropriate new wrappers.
1377 ;;; OBSOLETE-INSTANCE-TRAP might be called on structure instances
1378 ;;; after a structure is redefined. In most cases,
1379 ;;; OBSOLETE-INSTANCE-TRAP will not be able to fix the old instance,
1380 ;;; so it must signal an error. The hard part of this is that the
1381 ;;; error system and debugger might cause OBSOLETE-INSTANCE-TRAP to be
1382 ;;; called again, so in that case, we have to return some reasonable
1383 ;;; wrapper, instead.
1385 (defvar *in-obsolete-instance-trap* nil)
1386 (defvar *the-wrapper-of-structure-object*
1387 (class-wrapper (find-class 'structure-object)))
1389 (define-condition obsolete-structure (error)
1390 ((datum :reader obsolete-structure-datum :initarg :datum))
1392 (lambda (condition stream)
1393 ;; Don't try to print the structure, since it probably won't work.
1395 "~@<obsolete structure error for a structure of type ~2I~_~S~:>"
1396 (type-of (obsolete-structure-datum condition))))))
1398 (defun %obsolete-instance-trap (owrapper nwrapper instance)
1399 (if (not (layout-for-std-class-p owrapper))
1400 (if *in-obsolete-instance-trap*
1401 *the-wrapper-of-structure-object*
1402 (let ((*in-obsolete-instance-trap* t))
1403 (error 'obsolete-structure :datum instance)))
1404 (let* ((class (wrapper-class* nwrapper))
1405 (copy (allocate-instance class)) ;??? allocate-instance ???
1406 (olayout (wrapper-instance-slots-layout owrapper))
1407 (nlayout (wrapper-instance-slots-layout nwrapper))
1408 (oslots (get-slots instance))
1409 (nslots (get-slots copy))
1410 (oclass-slots (wrapper-class-slots owrapper))
1415 ;; local --> local transfer value
1416 ;; local --> shared discard value, discard slot
1417 ;; local --> -- discard slot
1418 ;; shared --> local transfer value
1419 ;; shared --> shared -- (cf SHARED-INITIALIZE :AFTER STD-CLASS)
1420 ;; shared --> -- discard value
1421 ;; -- --> local add slot
1424 ;; Go through all the old local slots.
1426 (dolist (name olayout)
1427 (let ((npos (posq name nlayout)))
1429 (setf (clos-slots-ref nslots npos)
1430 (clos-slots-ref oslots opos))
1432 (push name discarded)
1433 (unless (eq (clos-slots-ref oslots opos) +slot-unbound+)
1434 (setf (getf plist name) (clos-slots-ref oslots opos))))))
1437 ;; Go through all the old shared slots.
1438 (dolist (oclass-slot-and-val oclass-slots)
1439 (let ((name (car oclass-slot-and-val))
1440 (val (cdr oclass-slot-and-val)))
1441 (let ((npos (posq name nlayout)))
1443 (setf (clos-slots-ref nslots npos) val)))))
1445 ;; Go through all the new local slots to compute the added slots.
1446 (dolist (nlocal nlayout)
1447 (unless (or (memq nlocal olayout)
1448 (assq nlocal oclass-slots))
1449 (push nlocal added)))
1451 (%swap-wrappers-and-slots instance copy)
1453 (update-instance-for-redefined-class instance
1459 (defun %change-class (instance new-class initargs)
1460 (let* ((old-class (class-of instance))
1461 (copy (allocate-instance new-class))
1462 (new-wrapper (get-wrapper copy))
1463 (old-wrapper (class-wrapper old-class))
1464 (old-layout (wrapper-instance-slots-layout old-wrapper))
1465 (new-layout (wrapper-instance-slots-layout new-wrapper))
1466 (old-slots (get-slots instance))
1467 (new-slots (get-slots copy))
1468 (old-class-slots (wrapper-class-slots old-wrapper)))
1470 ;; "The values of local slots specified by both the class CTO and
1471 ;; CFROM are retained. If such a local slot was unbound, it
1472 ;; remains unbound."
1473 (let ((new-position 0))
1474 (dolist (new-slot new-layout)
1475 (let ((old-position (posq new-slot old-layout)))
1477 (setf (clos-slots-ref new-slots new-position)
1478 (clos-slots-ref old-slots old-position))))
1479 (incf new-position)))
1481 ;; "The values of slots specified as shared in the class CFROM and
1482 ;; as local in the class CTO are retained."
1483 (dolist (slot-and-val old-class-slots)
1484 (let ((position (posq (car slot-and-val) new-layout)))
1486 (setf (clos-slots-ref new-slots position) (cdr slot-and-val)))))
1488 ;; Make the copy point to the old instance's storage, and make the
1489 ;; old instance point to the new storage.
1490 (%swap-wrappers-and-slots instance copy)
1492 (apply #'update-instance-for-different-class copy instance initargs)
1496 (defmethod change-class ((instance standard-object) (new-class standard-class)
1499 (unless (class-finalized-p new-class)
1500 (finalize-inheritance new-class))
1501 (let ((cpl (class-precedence-list new-class)))
1505 `(when (eq class (find-class ',class-name))
1506 (error 'metaobject-initialization-violation
1507 :format-control "~@<Cannot ~S objects into ~S metaobjects.~@:>"
1508 :format-arguments (list 'change-class ',class-name)
1509 :references (list '(:amop :initialization ,class-name))))))
1511 (frob generic-function)
1513 (frob slot-definition))))
1514 (%change-class instance new-class initargs)))
1516 (defmethod change-class ((instance forward-referenced-class)
1517 (new-class standard-class) &rest initargs)
1519 (let ((cpl (class-precedence-list new-class)))
1521 (error 'metaobject-initialization-violation
1523 "~@<Cannot ~S ~S objects into non-~S objects.~@:>"
1525 (list 'change-class 'forward-referenced-class 'class)
1527 (list '(:amop :generic-function ensure-class-using-class)
1528 '(:amop :initialization class))))
1529 (when (eq class (find-class 'class))
1531 (%change-class instance new-class initargs)))
1533 (defmethod change-class ((instance funcallable-standard-object)
1534 (new-class funcallable-standard-class)
1537 (let ((cpl (class-precedence-list new-class)))
1541 `(when (eq class (find-class ',class-name))
1542 (error 'metaobject-initialization-violation
1543 :format-control "~@<Cannot ~S objects into ~S metaobjects.~@:>"
1544 :format-arguments (list 'change-class ',class-name)
1545 :references (list '(:amop :initialization ,class-name))))))
1547 (frob generic-function)
1549 (frob slot-definition))))
1550 (%change-class instance new-class initargs)))
1552 (defmethod change-class ((instance standard-object)
1553 (new-class funcallable-standard-class)
1555 (declare (ignore initargs))
1556 (error "You can't change the class of ~S to ~S~@
1557 because it isn't already an instance with metaclass ~S."
1558 instance new-class 'standard-class))
1560 (defmethod change-class ((instance funcallable-standard-object)
1561 (new-class standard-class)
1563 (declare (ignore initargs))
1564 (error "You can't change the class of ~S to ~S~@
1565 because it isn't already an instance with metaclass ~S."
1566 instance new-class 'funcallable-standard-class))
1568 (defmethod change-class ((instance t) (new-class-name symbol) &rest initargs)
1569 (apply #'change-class instance (find-class new-class-name) initargs))
1571 ;;;; The metaclass BUILT-IN-CLASS
1573 ;;;; This metaclass is something of a weird creature. By this point, all
1574 ;;;; instances of it which will exist have been created, and no instance
1575 ;;;; is ever created by calling MAKE-INSTANCE.
1577 ;;;; But, there are other parts of the protocol we must follow and those
1578 ;;;; definitions appear here.
1580 (macrolet ((def (name args control)
1581 `(defmethod ,name ,args
1582 (declare (ignore initargs))
1583 (error 'metaobject-initialization-violation
1584 :format-control ,(format nil "~@<~A~@:>" control)
1585 :format-arguments (list ',name)
1586 :references (list '(:amop :initialization "Class"))))))
1587 (def initialize-instance ((class built-in-class) &rest initargs)
1588 "Cannot ~S an instance of BUILT-IN-CLASS.")
1589 (def reinitialize-instance ((class built-in-class) &rest initargs)
1590 "Cannot ~S an instance of BUILT-IN-CLASS."))
1592 (macrolet ((def (name)
1593 `(defmethod ,name ((class built-in-class)) nil)))
1594 (def class-direct-slots)
1596 (def class-direct-default-initargs)
1597 (def class-default-initargs))
1599 (defmethod validate-superclass ((c class) (s built-in-class))
1600 (or (eq s *the-class-t*) (eq s *the-class-stream*)
1601 ;; FIXME: bad things happen if someone tries to mix in both
1602 ;; FILE-STREAM and STRING-STREAM (as they have the same
1603 ;; layout-depthoid). Is there any way we can provide a useful
1604 ;; error message? -- CSR, 2005-05-03
1605 (eq s *the-class-file-stream*) (eq s *the-class-string-stream*)
1606 ;; This probably shouldn't be mixed in with certain other
1607 ;; classes, too, but it seems to work both with STANDARD-OBJECT
1608 ;; and FUNCALLABLE-STANDARD-OBJECT
1609 (eq s *the-class-sequence*)))
1611 ;;; Some necessary methods for FORWARD-REFERENCED-CLASS
1612 (defmethod class-direct-slots ((class forward-referenced-class)) ())
1613 (defmethod class-direct-default-initargs ((class forward-referenced-class)) ())
1614 (macrolet ((def (method)
1615 `(defmethod ,method ((class forward-referenced-class))
1616 (error "~@<~I~S was called on a forward referenced class:~2I~_~S~:>"
1618 (def class-default-initargs)
1619 (def class-precedence-list)
1622 (defmethod validate-superclass ((c slot-class)
1623 (f forward-referenced-class))
1626 (defmethod add-dependent ((metaobject dependent-update-mixin) dependent)
1627 (pushnew dependent (plist-value metaobject 'dependents) :test #'eq))
1629 (defmethod remove-dependent ((metaobject dependent-update-mixin) dependent)
1630 (setf (plist-value metaobject 'dependents)
1631 (delete dependent (plist-value metaobject 'dependents))))
1633 (defmethod map-dependents ((metaobject dependent-update-mixin) function)
1634 (dolist (dependent (plist-value metaobject 'dependents))
1635 (funcall function dependent)))