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 ;;;; ANSI CL condition for unbound slots
28 (define-condition unbound-slot (cell-error)
29 ((instance :reader unbound-slot-instance :initarg :instance)
30 (slot :reader unbound-slot-slot :initarg :slot))
31 (:report (lambda(condition stream)
32 (format stream "The slot ~S is unbound in the object ~S."
33 (unbound-slot-slot condition)
34 (unbound-slot-instance condition)))))
36 (defmethod wrapper-fetcher ((class standard-class))
37 'std-instance-wrapper)
39 (defmethod slots-fetcher ((class standard-class))
42 (defmethod raw-instance-allocator ((class standard-class))
43 'allocate-standard-instance)
45 ;;; These four functions work on std-instances and fsc-instances. These are
46 ;;; instances for which it is possible to change the wrapper and the slots.
48 ;;; For these kinds of instances, most specified methods from the instance
49 ;;; structure protocol are promoted to the implementation-specific class
50 ;;; std-class. Many of these methods call these four functions.
52 (defun set-wrapper (inst new)
53 (cond ((std-instance-p inst)
54 (setf (std-instance-wrapper inst) new))
55 ((fsc-instance-p inst)
56 (setf (fsc-instance-wrapper inst) new))
58 (error "unrecognized instance type"))))
60 (defun swap-wrappers-and-slots (i1 i2)
61 (sb-sys:without-interrupts
62 (cond ((std-instance-p i1)
63 (let ((w1 (std-instance-wrapper i1))
64 (s1 (std-instance-slots i1)))
65 (setf (std-instance-wrapper i1) (std-instance-wrapper i2))
66 (setf (std-instance-slots i1) (std-instance-slots i2))
67 (setf (std-instance-wrapper i2) w1)
68 (setf (std-instance-slots i2) s1)))
70 (let ((w1 (fsc-instance-wrapper i1))
71 (s1 (fsc-instance-slots i1)))
72 (setf (fsc-instance-wrapper i1) (fsc-instance-wrapper i2))
73 (setf (fsc-instance-slots i1) (fsc-instance-slots i2))
74 (setf (fsc-instance-wrapper i2) w1)
75 (setf (fsc-instance-slots i2) s1)))
77 (error "unrecognized instance type")))))
79 (defun get-class-slot-value-1 (object wrapper slot-name)
80 (let ((entry (assoc slot-name (wrapper-class-slots wrapper))))
82 (slot-missing (wrapper-class wrapper) object slot-name 'slot-value)
83 (if (eq (cdr entry) +slot-unbound+)
84 (slot-unbound (wrapper-class wrapper) object slot-name)
87 (defun set-class-slot-value-1 (new-value object wrapper slot-name)
88 (let ((entry (assoc slot-name (wrapper-class-slots wrapper))))
90 (slot-missing (wrapper-class wrapper)
95 (setf (cdr entry) new-value))))
97 (defmethod class-slot-value ((class std-class) slot-name)
98 (let ((wrapper (class-wrapper class))
99 (prototype (class-prototype class)))
100 (get-class-slot-value-1 prototype wrapper slot-name)))
102 (defmethod (setf class-slot-value) (nv (class std-class) slot-name)
103 (let ((wrapper (class-wrapper class))
104 (prototype (class-prototype class)))
105 (set-class-slot-value-1 nv prototype wrapper slot-name)))
107 (defun find-slot-definition (class slot-name)
108 (dolist (slot (class-slots class) nil)
109 (when (eql slot-name (slot-definition-name slot))
112 (defun slot-value (object slot-name)
113 (let* ((class (class-of object))
114 (slot-definition (find-slot-definition class slot-name)))
115 (if (null slot-definition)
116 (slot-missing class object slot-name 'slot-value)
117 (slot-value-using-class class object slot-definition))))
119 (setf (gdefinition 'slot-value-normal) #'slot-value)
121 (define-compiler-macro slot-value (object-form slot-name-form)
122 (if (and (constantp slot-name-form)
123 (let ((slot-name (eval slot-name-form)))
124 (and (symbolp slot-name) (symbol-package slot-name))))
125 `(accessor-slot-value ,object-form ,slot-name-form)
126 `(slot-value-normal ,object-form ,slot-name-form)))
128 (defun set-slot-value (object slot-name new-value)
129 (let* ((class (class-of object))
130 (slot-definition (find-slot-definition class slot-name)))
131 (if (null slot-definition)
132 (slot-missing class object slot-name 'setf new-value)
133 (setf (slot-value-using-class class object slot-definition)
136 (setf (gdefinition 'set-slot-value-normal) #'set-slot-value)
138 (define-compiler-macro set-slot-value (object-form
141 (if (and (constantp slot-name-form)
142 (let ((slot-name (eval slot-name-form)))
143 (and (symbolp slot-name) (symbol-package slot-name))))
144 `(accessor-set-slot-value ,object-form ,slot-name-form ,new-value-form)
145 `(set-slot-value-normal ,object-form ,slot-name-form ,new-value-form)))
147 (defun slot-boundp (object slot-name)
148 (let* ((class (class-of object))
149 (slot-definition (find-slot-definition class slot-name)))
150 (if (null slot-definition)
151 (slot-missing class object slot-name 'slot-boundp)
152 (slot-boundp-using-class class object slot-definition))))
154 (setf (gdefinition 'slot-boundp-normal) #'slot-boundp)
156 (define-compiler-macro slot-boundp (object-form slot-name-form)
157 (if (and (constantp slot-name-form)
158 (let ((slot-name (eval slot-name-form)))
159 (and (symbolp slot-name) (symbol-package slot-name))))
160 `(accessor-slot-boundp ,object-form ,slot-name-form)
161 `(slot-boundp-normal ,object-form ,slot-name-form)))
163 (defun slot-makunbound (object slot-name)
164 (let* ((class (class-of object))
165 (slot-definition (find-slot-definition class slot-name)))
166 (if (null slot-definition)
167 (slot-missing class object slot-name 'slot-makunbound)
168 (slot-makunbound-using-class class object slot-definition))))
170 (defun slot-exists-p (object slot-name)
171 (let ((class (class-of object)))
172 (not (null (find-slot-definition class slot-name)))))
174 ;;; This isn't documented, but is used within PCL in a number of print
175 ;;; object methods. (See NAMED-OBJECT-PRINT-FUNCTION.)
176 (defun slot-value-or-default (object slot-name &optional (default "unbound"))
177 (if (slot-boundp object slot-name)
178 (slot-value object slot-name)
181 (defun standard-instance-access (instance location)
182 (clos-slots-ref (std-instance-slots instance) location))
184 (defun funcallable-standard-instance-access (instance location)
185 (clos-slots-ref (fsc-instance-slots instance) location))
187 (defmethod slot-value-using-class ((class std-class)
189 (slotd standard-effective-slot-definition))
190 (let* ((location (slot-definition-location slotd))
191 (value (typecase location
193 (cond ((std-instance-p object)
194 ;; FIXME: EQ T (WRAPPER-STATE ..) is better done
195 ;; through INVALID-WRAPPER-P (here and below).
196 (unless (eq t (wrapper-state (std-instance-wrapper
198 (check-wrapper-validity object))
199 (clos-slots-ref (std-instance-slots object)
201 ((fsc-instance-p object)
202 (unless (eq t (wrapper-state (fsc-instance-wrapper
204 (check-wrapper-validity object))
205 (clos-slots-ref (fsc-instance-slots object)
207 (t (error "unrecognized instance type"))))
211 (error "~@<The slot ~S has neither :INSTANCE nor :CLASS ~
212 allocation, so it can't be read by the default ~
214 slotd 'slot-value-using-class)))))
215 (if (eq value +slot-unbound+)
216 (slot-unbound class object (slot-definition-name slotd))
219 (defmethod (setf slot-value-using-class)
220 (new-value (class std-class)
222 (slotd standard-effective-slot-definition))
223 (let ((location (slot-definition-location slotd)))
226 (cond ((std-instance-p object)
227 (unless (eq t (wrapper-state (std-instance-wrapper object)))
228 (check-wrapper-validity object))
229 (setf (clos-slots-ref (std-instance-slots object) location)
231 ((fsc-instance-p object)
232 (unless (eq t (wrapper-state (fsc-instance-wrapper object)))
233 (check-wrapper-validity object))
234 (setf (clos-slots-ref (fsc-instance-slots object) location)
236 (t (error "unrecognized instance type"))))
238 (setf (cdr location) new-value))
240 (error "~@<The slot ~S has neither :INSTANCE nor :CLASS allocation, ~
241 so it can't be written by the default ~S method.~:@>"
242 slotd '(setf slot-value-using-class))))))
244 (defmethod slot-boundp-using-class
247 (slotd standard-effective-slot-definition))
248 (let* ((location (slot-definition-location slotd))
249 (value (typecase location
251 (cond ((std-instance-p object)
252 (unless (eq t (wrapper-state (std-instance-wrapper
254 (check-wrapper-validity object))
255 (clos-slots-ref (std-instance-slots object)
257 ((fsc-instance-p object)
258 (unless (eq t (wrapper-state (fsc-instance-wrapper
260 (check-wrapper-validity object))
261 (clos-slots-ref (fsc-instance-slots object)
263 (t (error "unrecognized instance type"))))
267 (error "~@<The slot ~S has neither :INSTANCE nor :CLASS ~
268 allocation, so it can't be read by the default ~S ~
270 slotd 'slot-boundp-using-class)))))
271 (not (eq value +slot-unbound+))))
273 (defmethod slot-makunbound-using-class
276 (slotd standard-effective-slot-definition))
277 (let ((location (slot-definition-location slotd)))
280 (cond ((std-instance-p object)
281 (unless (eq t (wrapper-state (std-instance-wrapper object)))
282 (check-wrapper-validity object))
283 (setf (clos-slots-ref (std-instance-slots object) location)
285 ((fsc-instance-p object)
286 (unless (eq t (wrapper-state (fsc-instance-wrapper object)))
287 (check-wrapper-validity object))
288 (setf (clos-slots-ref (fsc-instance-slots object) location)
290 (t (error "unrecognized instance type"))))
292 (setf (cdr location) +slot-unbound+))
294 (error "~@<The slot ~S has neither :INSTANCE nor :CLASS allocation, ~
295 so it can't be written by the default ~S method.~@:>"
296 slotd 'slot-makunbound-using-class))))
299 (defmethod slot-value-using-class
300 ((class structure-class)
301 (object structure-object)
302 (slotd structure-effective-slot-definition))
303 (let* ((function (slot-definition-internal-reader-function slotd))
304 (value (funcall function object)))
305 (declare (type function function))
306 (if (eq value +slot-unbound+)
307 (slot-unbound class object (slot-definition-name slotd))
310 (defmethod (setf slot-value-using-class)
311 (new-value (class structure-class)
312 (object structure-object)
313 (slotd structure-effective-slot-definition))
314 (let ((function (slot-definition-internal-writer-function slotd)))
315 (declare (type function function))
316 (funcall function new-value object)))
318 (defmethod slot-boundp-using-class
319 ((class structure-class)
320 (object structure-object)
321 (slotd structure-effective-slot-definition))
324 (defmethod slot-makunbound-using-class
325 ((class structure-class)
326 (object structure-object)
327 (slotd structure-effective-slot-definition))
328 (error "Structure slots can't be unbound."))
330 (defmethod slot-missing
331 ((class t) instance slot-name operation &optional new-value)
332 (error "~@<When attempting to ~A, the slot ~S is missing from the ~
335 (slot-value "read the slot's value (slot-value)")
337 "set the slot's value to ~S (SETF of SLOT-VALUE)"
339 (slot-boundp "test to see whether slot is bound (SLOT-BOUNDP)")
340 (slot-makunbound "make the slot unbound (SLOT-MAKUNBOUND)"))
344 (defmethod slot-unbound ((class t) instance slot-name)
345 (error 'unbound-slot :slot slot-name :instance instance))
347 (defun slot-unbound-internal (instance position)
348 (slot-unbound (class-of instance) instance
352 (wrapper-instance-slots-layout (wrapper-of instance))))
356 (defmethod allocate-instance ((class standard-class) &rest initargs)
357 (declare (ignore initargs))
358 (unless (class-finalized-p class) (finalize-inheritance class))
359 (allocate-standard-instance (class-wrapper class)))
361 (defmethod allocate-instance ((class structure-class) &rest initargs)
362 (declare (ignore initargs))
363 (let ((constructor (class-defstruct-constructor class)))
365 (funcall constructor)
366 (error "can't allocate an instance of class ~S" (class-name class)))))