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 (:report
(lambda (condition stream
)
31 (format stream
"The slot ~S is unbound in the object ~S."
32 (cell-error-name condition
)
33 (unbound-slot-instance condition
)))))
35 (defmethod wrapper-fetcher ((class standard-class
))
36 'std-instance-wrapper
)
38 (defmethod slots-fetcher ((class standard-class
))
41 (defmethod raw-instance-allocator ((class standard-class
))
42 'allocate-standard-instance
)
44 ;;; These three functions work on std-instances and fsc-instances. These are
45 ;;; instances for which it is possible to change the wrapper and the slots.
47 ;;; For these kinds of instances, most specified methods from the instance
48 ;;; structure protocol are promoted to the implementation-specific class
49 ;;; std-class. Many of these methods call these four functions.
51 (defun %swap-wrappers-and-slots
(i1 i2
)
52 (cond ((std-instance-p i1
)
53 (let ((w1 (std-instance-wrapper i1
))
54 (s1 (std-instance-slots i1
)))
55 (setf (std-instance-wrapper i1
) (std-instance-wrapper i2
))
56 (setf (std-instance-slots i1
) (std-instance-slots i2
))
57 (setf (std-instance-wrapper i2
) w1
)
58 (setf (std-instance-slots i2
) s1
)))
60 (let ((w1 (fsc-instance-wrapper i1
))
61 (s1 (fsc-instance-slots i1
)))
62 (setf (fsc-instance-wrapper i1
) (fsc-instance-wrapper i2
))
63 (setf (fsc-instance-slots i1
) (fsc-instance-slots i2
))
64 (setf (fsc-instance-wrapper i2
) w1
)
65 (setf (fsc-instance-slots i2
) s1
)))
67 (error "unrecognized instance type"))))
69 ;;;; STANDARD-INSTANCE-ACCESS
71 (declaim (inline standard-instance-access
(setf standard-instance-access
)
72 funcallable-standard-instance-access
73 (setf funcallable-standard-instance-access
)))
75 (defun standard-instance-access (instance location
)
76 (clos-slots-ref (std-instance-slots instance
) location
))
78 (defun (setf standard-instance-access
) (new-value instance location
)
79 (setf (clos-slots-ref (std-instance-slots instance
) location
) new-value
))
81 (defun funcallable-standard-instance-access (instance location
)
82 (clos-slots-ref (fsc-instance-slots instance
) location
))
84 (defun (setf funcallable-standard-instance-access
) (new-value instance location
)
85 (setf (clos-slots-ref (fsc-instance-slots instance
) location
) new-value
))
87 ;;;; SLOT-VALUE, (SETF SLOT-VALUE), SLOT-BOUNDP, SLOT-MAKUNBOUND
89 (declaim (ftype (sfunction (t symbol
) t
) slot-value
))
90 (defun slot-value (object slot-name
)
91 (let* ((wrapper (valid-wrapper-of object
))
92 (cell (find-slot-cell wrapper slot-name
))
95 (cond ((fixnump location
)
96 (if (std-instance-p object
)
97 (standard-instance-access object location
)
98 (funcallable-standard-instance-access object location
)))
102 (return-from slot-value
103 (values (slot-missing (wrapper-class* wrapper
) object slot-name
106 (return-from slot-value
107 (slot-value-using-class (wrapper-class* wrapper
) object
(cddr cell
))))
109 (bug "Bogus slot cell in SLOT-VALUE: ~S" cell
)))))
110 (if (eq +slot-unbound
+ value
)
111 (slot-unbound (wrapper-class* wrapper
) object slot-name
)
114 ;;; This is used during the PCL build, but gets replaced by a deftransform
116 (define-compiler-macro slot-value
(&whole form object slot-name
118 (if (and (constantp slot-name env
)
119 (interned-symbol-p (constant-form-value slot-name env
)))
120 `(accessor-slot-value ,object
,slot-name
)
123 (defun set-slot-value (object slot-name new-value
)
124 (let* ((wrapper (valid-wrapper-of object
))
125 (cell (find-slot-cell wrapper slot-name
))
126 (location (car cell
))
127 (type-check-function (cadr cell
)))
128 (when type-check-function
129 (funcall (the function type-check-function
) new-value
))
130 (cond ((fixnump location
)
131 (if (std-instance-p object
)
132 (setf (standard-instance-access object location
) new-value
)
133 (setf (funcallable-standard-instance-access object location
)
136 (setf (cdr location
) new-value
))
138 (slot-missing (wrapper-class* wrapper
) object slot-name
'setf new-value
))
140 (setf (slot-value-using-class (wrapper-class* wrapper
) object
(cddr cell
))
143 (bug "Bogus slot-cell in SET-SLOT-VALUE: ~S" cell
))))
146 ;;; A version of SET-SLOT-VALUE for use in safe code, where we want to
147 ;;; check types when writing to slots:
148 ;;; * Doesn't have an optimizing compiler-macro
149 ;;; * Isn't special-cased in WALK-METHOD-LAMBDA
150 (defun safe-set-slot-value (object slot-name new-value
)
151 (set-slot-value object slot-name new-value
))
153 ;;; This is used during the PCL build, but gets replaced by a deftransform
155 (define-compiler-macro set-slot-value
(&whole form object slot-name new-value
157 (if (and (constantp slot-name env
)
158 (interned-symbol-p (constant-form-value slot-name env
))
159 ;; We can't use the ACCESSOR-SET-SLOT-VALUE path in safe
160 ;; code, since it'll use the global automatically generated
161 ;; accessor, which won't do typechecking. (SLOT-OBJECT
162 ;; won't have been compiled with SAFETY 3, so SAFE-P will
163 ;; be NIL in MAKE-STD-WRITER-METHOD-FUNCTION).
164 (not (safe-code-p env
)))
165 `(accessor-set-slot-value ,object
,slot-name
,new-value
)
168 (defun slot-boundp (object slot-name
)
169 (let* ((wrapper (valid-wrapper-of object
))
170 (cell (find-slot-cell wrapper slot-name
))
171 (location (car cell
))
173 (cond ((fixnump location
)
174 (if (std-instance-p object
)
175 (standard-instance-access object location
)
176 (funcallable-standard-instance-access object location
)))
180 (return-from slot-boundp
181 (and (slot-missing (wrapper-class* wrapper
) object slot-name
185 (return-from slot-boundp
186 (slot-boundp-using-class (wrapper-class* wrapper
) object
(cddr cell
))))
188 (bug "Bogus slot cell in SLOT-VALUE: ~S" cell
)))))
189 (not (eq +slot-unbound
+ value
))))
191 (define-compiler-macro slot-boundp
(&whole form object slot-name
193 (if (and (constantp slot-name env
)
194 (interned-symbol-p (constant-form-value slot-name env
)))
195 `(accessor-slot-boundp ,object
,slot-name
)
198 (defun slot-makunbound (object slot-name
)
199 (let* ((wrapper (valid-wrapper-of object
))
200 (cell (find-slot-cell wrapper slot-name
))
201 (location (car cell
)))
202 (cond ((fixnump location
)
203 (if (std-instance-p object
)
204 (setf (standard-instance-access object location
) +slot-unbound
+)
205 (setf (funcallable-standard-instance-access object location
)
208 (setf (cdr location
) +slot-unbound
+))
210 (slot-missing (wrapper-class* wrapper
) object slot-name
'slot-makunbound
))
212 (slot-makunbound-using-class (wrapper-class* wrapper
) object
(cddr cell
)))
214 (bug "Bogus slot-cell in SLOT-MAKUNBOUND: ~S" cell
))))
217 (defun slot-exists-p (object slot-name
)
218 (let ((class (class-of object
)))
219 (not (null (find-slot-definition class slot-name
)))))
221 (defvar *unbound-slot-value-marker
* (make-unprintable-object "unbound slot"))
223 ;;; This isn't documented, but is used within PCL in a number of print
224 ;;; object methods. (See NAMED-OBJECT-PRINT-FUNCTION.)
225 (defun slot-value-or-default (object slot-name
&optional
226 (default *unbound-slot-value-marker
*))
227 (if (slot-boundp object slot-name
)
228 (slot-value object slot-name
)
231 (defmethod slot-value-using-class ((class std-class
)
232 (object standard-object
)
233 (slotd standard-effective-slot-definition
))
234 ;; FIXME: Do we need this? SLOT-VALUE checks for obsolete
235 ;; instances. Are users allowed to call this directly?
236 (check-obsolete-instance object
)
237 (let* ((location (slot-definition-location slotd
))
241 (cond ((std-instance-p object
)
242 (clos-slots-ref (std-instance-slots object
)
244 ((fsc-instance-p object
)
245 (clos-slots-ref (fsc-instance-slots object
)
247 (t (bug "unrecognized instance type in ~S"
248 'slot-value-using-class
))))
252 (instance-structure-protocol-error slotd
253 'slot-value-using-class
)))))
254 (if (eq value
+slot-unbound
+)
255 (values (slot-unbound class object
(slot-definition-name slotd
)))
258 (defmethod (setf slot-value-using-class
)
259 (new-value (class std-class
)
260 (object standard-object
)
261 (slotd standard-effective-slot-definition
))
262 ;; FIXME: Do we need this? SET-SLOT-VALUE checks for obsolete
263 ;; instances. Are users allowed to call this directly?
264 (check-obsolete-instance object
)
265 (let ((location (slot-definition-location slotd
))
268 (slot-definition-type-check-function slotd
))))
269 (flet ((check (new-value)
270 (when type-check-function
271 (funcall (the function type-check-function
) new-value
))
275 (cond ((std-instance-p object
)
276 (setf (clos-slots-ref (std-instance-slots object
) location
)
278 ((fsc-instance-p object
)
279 (setf (clos-slots-ref (fsc-instance-slots object
) location
)
281 (t (bug "unrecognized instance type in ~S"
282 '(setf slot-value-using-class
)))))
284 (setf (cdr location
) (check new-value
)))
286 (instance-structure-protocol-error
287 slotd
'(setf slot-value-using-class
)))))))
289 (defmethod slot-boundp-using-class
291 (object standard-object
)
292 (slotd standard-effective-slot-definition
))
293 ;; FIXME: Do we need this? SLOT-BOUNDP checks for obsolete
294 ;; instances. Are users allowed to call this directly?
295 (check-obsolete-instance object
)
296 (let* ((location (slot-definition-location slotd
))
300 (cond ((std-instance-p object
)
301 (clos-slots-ref (std-instance-slots object
)
303 ((fsc-instance-p object
)
304 (clos-slots-ref (fsc-instance-slots object
)
306 (t (bug "unrecognized instance type in ~S"
307 'slot-boundp-using-class
))))
311 (instance-structure-protocol-error slotd
312 'slot-boundp-using-class
)))))
313 (not (eq value
+slot-unbound
+))))
315 (defmethod slot-makunbound-using-class
317 (object standard-object
)
318 (slotd standard-effective-slot-definition
))
319 (check-obsolete-instance object
)
320 (let ((location (slot-definition-location slotd
)))
323 (cond ((std-instance-p object
)
324 (setf (clos-slots-ref (std-instance-slots object
) location
)
326 ((fsc-instance-p object
)
327 (setf (clos-slots-ref (fsc-instance-slots object
) location
)
329 (t (bug "unrecognized instance type in ~S"
330 'slot-makunbound-using-class
))))
332 (setf (cdr location
) +slot-unbound
+))
334 (instance-structure-protocol-error slotd
335 'slot-makunbound-using-class
))))
338 (defmethod slot-value-using-class
339 ((class condition-class
)
341 (slotd condition-effective-slot-definition
))
342 (let ((fun (slot-definition-reader-function slotd
)))
343 (declare (type function fun
))
344 (funcall fun object
)))
346 (defmethod (setf slot-value-using-class
)
348 (class condition-class
)
350 (slotd condition-effective-slot-definition
))
351 (let ((fun (slot-definition-writer-function slotd
)))
352 (declare (type function fun
))
353 (funcall fun new-value object
)))
355 (defmethod slot-boundp-using-class
356 ((class condition-class
)
358 (slotd condition-effective-slot-definition
))
359 (let ((fun (slot-definition-boundp-function slotd
)))
360 (declare (type function fun
))
361 (funcall fun object
)))
363 (defmethod slot-makunbound-using-class ((class condition-class
) object slot
)
364 (error "attempt to unbind slot ~S in condition object ~S."
367 (defmethod slot-value-using-class
368 ((class structure-class
)
369 (object structure-object
)
370 (slotd structure-effective-slot-definition
))
371 (let* ((function (slot-definition-internal-reader-function slotd
))
372 (value (funcall function object
)))
373 (declare (type function function
))
374 ;; FIXME: Is this really necessary? Structure slots should surely
376 (if (eq value
+slot-unbound
+)
377 (values (slot-unbound class object
(slot-definition-name slotd
)))
380 (defmethod (setf slot-value-using-class
)
381 (new-value (class structure-class
)
382 (object structure-object
)
383 (slotd structure-effective-slot-definition
))
384 (let ((function (slot-definition-internal-writer-function slotd
)))
385 (declare (type function function
))
386 (funcall function new-value object
)))
388 (defmethod slot-boundp-using-class
389 ((class structure-class
)
390 (object structure-object
)
391 (slotd structure-effective-slot-definition
))
394 (defmethod slot-makunbound-using-class
395 ((class structure-class
)
396 (object structure-object
)
397 (slotd structure-effective-slot-definition
))
398 (error "Structure slots can't be unbound."))
400 (defmethod slot-missing
401 ((class t
) instance slot-name operation
&optional new-value
)
402 (error "~@<When attempting to ~A, the slot ~S is missing from the ~
405 (slot-value "read the slot's value (slot-value)")
407 "set the slot's value to ~S (SETF of SLOT-VALUE)"
409 (slot-boundp "test to see whether slot is bound (SLOT-BOUNDP)")
410 (slot-makunbound "make the slot unbound (SLOT-MAKUNBOUND)"))
414 (defmethod slot-unbound ((class t
) instance slot-name
)
416 (error 'unbound-slot
:name slot-name
:instance instance
)
418 :report
"Return a value as the slot-value."
419 :interactive read-evaluated-form
422 :report
"Store and return a value as the slot-value."
423 :interactive read-evaluated-form
424 (setf (slot-value instance slot-name
) v
))))
426 (defun slot-unbound-internal (instance position
)
433 (nth position
(wrapper-instance-slots-layout (wrapper-of instance
))))
437 ;;; FIXME: AMOP says that allocate-instance imples finalize-inheritance
438 ;;; if the class is not yet finalized, but we don't seem to be taking
439 ;;; care of this for non-standard-classes.x
440 (defmethod allocate-instance ((class standard-class
) &rest initargs
)
441 (declare (ignore initargs
))
442 (unless (class-finalized-p class
)
443 (finalize-inheritance class
))
444 (allocate-standard-instance (class-wrapper class
)))
446 (defmethod allocate-instance ((class structure-class
) &rest initargs
)
447 (declare (ignore initargs
))
448 (let ((constructor (class-defstruct-constructor class
)))
450 (funcall constructor
)
451 (error "Don't know how to allocate ~S" class
))))
453 ;;; FIXME: It would be nicer to have allocate-instance return
454 ;;; uninitialized objects for conditions as well.
455 (defmethod allocate-instance ((class condition-class
) &rest initargs
)
456 (declare (ignore initargs
))
457 (make-condition (class-name class
)))
459 (defmethod allocate-instance ((class built-in-class
) &rest initargs
)
460 (declare (ignore initargs
))
461 (error "Cannot allocate an instance of ~S." class
)) ; So sayeth AMOP
463 ;;; AMOP says that CLASS-SLOTS signals an error for unfinalized classes.
464 (defmethod class-slots :before
((class slot-class
))
465 (unless (class-finalized-p class
)
466 (error 'simple-reference-error
467 :format-control
"~S called on ~S, which is not yet finalized."
468 :format-arguments
(list 'class-slots class
)
469 :references
(list '(:amop
:generic-function class-slots
)))))