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 ;;;; DEFCLASS macro and close personal friends
28 ;;; state for the current DEFCLASS expansion
29 (defvar *initfunctions-for-this-defclass*)
30 (defvar *readers-for-this-defclass*)
31 (defvar *writers-for-this-defclass*)
32 (defvar *slot-names-for-this-defclass*)
34 ;;; Like the DEFMETHOD macro, the expansion of the DEFCLASS macro is
35 ;;; fixed. DEFCLASS always expands into a call to LOAD-DEFCLASS. Until
36 ;;; the meta-braid is set up, LOAD-DEFCLASS has a special definition
37 ;;; which simply collects all class definitions up, when the metabraid
38 ;;; is initialized it is done from those class definitions.
40 ;;; After the metabraid has been setup, and the protocol for defining
41 ;;; classes has been defined, the real definition of LOAD-DEFCLASS is
42 ;;; installed by the file std-class.lisp
43 (defmacro defclass (&environment env name direct-superclasses direct-slots &rest options)
44 (let (*initfunctions-for-this-defclass*
45 *readers-for-this-defclass* ;Truly a crock, but we got
46 *writers-for-this-defclass* ;to have it to live nicely.
47 *slot-names-for-this-defclass*)
48 ;; FIXME: It would be nice to collect all errors from the
49 ;; expansion of a defclass and signal them in a single go.
50 (multiple-value-bind (metaclass canonical-options)
51 (canonize-defclass-options name options)
52 (let ((canonical-slots (canonize-defclass-slots name direct-slots env))
53 ;; DEFSTRUCT-P should be true if the class is defined
54 ;; with a metaclass STRUCTURE-CLASS, so that a DEFSTRUCT
55 ;; is compiled for the class.
56 (defstruct-p (and (eq *boot-state* 'complete)
57 (let ((mclass (find-class metaclass nil)))
61 *the-class-structure-class*))))))
63 `(let ,(mapcar #'cdr *initfunctions-for-this-defclass*)
67 (list ,@canonical-slots)
68 (list ,@(apply #'append
70 '(:from-defclass-p t))
72 ',*readers-for-this-defclass*
73 ',*writers-for-this-defclass*
74 ',*slot-names-for-this-defclass*
75 (sb-c:source-location)))))
78 ;; FIXME: (YUK!) Why do we do this? Because in order
79 ;; to make the defstruct form, we need to know what
80 ;; the accessors for the slots are, so we need already
81 ;; to have hooked into the CLOS machinery.
83 ;; There may be a better way to do this: it would
84 ;; involve knowing enough about PCL to ask "what will
85 ;; my slot names and accessors be"; failing this, we
86 ;; currently just evaluate the whole kaboodle, and
87 ;; then use CLASS-DIRECT-SLOTS. -- CSR, 2002-06-07
89 (let* ((include (or (and direct-superclasses
90 (find-class (car direct-superclasses) nil))
91 (and (not (eq name 'structure-object))
92 *the-class-structure-object*)))
93 (defstruct-form (make-structure-class-defstruct-form
94 name (class-direct-slots (find-class name))
97 (eval-when (:compile-toplevel :load-toplevel :execute)
98 ,defstruct-form) ; really compile the defstruct-form
99 (eval-when (:compile-toplevel :load-toplevel :execute)
102 ;; By telling the type system at compile time about
103 ;; the existence of a class named NAME, we can avoid
104 ;; various bogus warnings about "type isn't defined yet"
105 ;; for code elsewhere in the same file which uses
106 ;; the name of the type.
108 ;; We only need to do this at compile time, because
109 ;; at load and execute time we write the actual
110 ;; full-blown class, so the "a class of this name is
111 ;; coming" note we write here would be irrelevant.
112 (eval-when (:compile-toplevel)
113 (%compiler-defclass ',name
114 ',*readers-for-this-defclass*
115 ',*writers-for-this-defclass*
116 ',*slot-names-for-this-defclass*))
117 (eval-when (:load-toplevel :execute)
118 ,defclass-form))))))))
120 (defun canonize-defclass-options (class-name options)
121 (maplist (lambda (sublist)
122 (let ((option-name (first (pop sublist))))
123 (when (member option-name sublist :key #'first)
124 (error 'simple-program-error
125 :format-control "Multiple ~S options in DEFCLASS ~S."
126 :format-arguments (list option-name class-name)))))
132 (dolist (option options)
133 (unless (listp option)
134 (error "~S is not a legal defclass option." option))
137 (let ((maybe-metaclass (second option)))
138 (unless (and maybe-metaclass (legal-class-name-p maybe-metaclass))
139 (error 'simple-program-error
140 :format-control "~@<The value of the :metaclass option (~S) ~
141 is not a legal class name.~:@>"
142 :format-arguments (list maybe-metaclass)))
143 (setf metaclass maybe-metaclass)))
145 (let (initargs arg-names)
146 (doplist (key val) (cdr option)
147 (when (member key arg-names)
148 (error 'simple-program-error
149 :format-control "~@<Duplicate initialization argument ~
150 name ~S in :DEFAULT-INITARGS of ~
152 :format-arguments (list key class-name)))
154 (push ``(,',key ,',val ,,(make-initfunction val)) initargs))
155 (setf default-initargs t)
156 (push `(:direct-default-initargs (list ,@(nreverse initargs)))
159 (unless (stringp (second option))
160 (error "~S is not a legal :documentation value" (second option)))
161 (setf documentation t)
162 (push `(:documentation ,(second option)) canonized-options))
164 (push `(',(car option) ',(cdr option)) canonized-options))))
165 (values (or metaclass 'standard-class) (nreverse canonized-options))))
167 (defun canonize-defclass-slots (class-name slots env)
168 (let (canonized-specs)
171 (setf spec (list spec)))
172 (when (and (cdr spec) (null (cddr spec)))
173 (error 'simple-program-error
174 :format-control "~@<in DEFCLASS ~S, the slot specification ~S ~
175 is invalid; the probable intended meaning may ~
176 be achieved by specifiying ~S instead.~:>"
177 :format-arguments (list class-name spec
178 `(,(car spec) :initform ,(cadr spec)))))
179 (let* ((name (car spec))
185 (unsupplied (list nil))
186 (initform unsupplied))
187 (check-slot-name-for-defclass name class-name env)
188 (push name *slot-names-for-this-defclass*)
189 (flet ((note-reader (x)
191 (error 'simple-program-error
192 :format-control "Slot reader name ~S for slot ~S in ~
193 DEFCLASS ~S is not a symbol."
194 :format-arguments (list x name class-name)))
196 (push x *readers-for-this-defclass*))
199 (push x *writers-for-this-defclass*)))
200 (doplist (key val) plist
202 (:accessor (note-reader val) (note-writer `(setf ,val)))
203 (:reader (note-reader val))
204 (:writer (note-writer val))
206 (unless (symbolp val)
207 (error 'simple-program-error
208 :format-control "Slot initarg name ~S for slot ~S in ~
209 DEFCLASS ~S is not a symbol."
210 :format-arguments (list val name class-name)))
213 (when (member key '(:initform :allocation :type :documentation))
214 (when (eq key :initform)
216 (when (get-properties others (list key))
217 (error 'simple-program-error
218 :format-control "Duplicate slot option ~S for slot ~
220 :format-arguments (list key name class-name))))
221 ;; For non-standard options multiple entries go in a list
222 (push val (getf others key))))))
223 ;; Unwrap singleton lists (AMOP 5.4.2)
224 (do ((head others (cddr head)))
226 (unless (cdr (second head))
227 (setf (second head) (car (second head)))))
228 (let ((canon `(:name ',name :readers ',readers :writers ',writers
229 :initargs ',initargs ',others)))
230 (push (if (eq initform unsupplied)
232 `(list* :initfunction ,(make-initfunction initform)
235 (nreverse canonized-specs)))
238 (defun check-slot-name-for-defclass (name class-name env)
239 (flet ((slot-name-illegal (reason)
240 (error 'simple-program-error
242 (format nil "~~@<In DEFCLASS ~~S, the slot name ~~S ~
244 :format-arguments (list class-name name))))
245 (cond ((not (symbolp name))
246 (slot-name-illegal "not a symbol"))
248 (slot-name-illegal "a keyword"))
249 ((constantp name env)
250 (slot-name-illegal "a constant"))
251 ((member name *slot-names-for-this-defclass*)
252 (error 'simple-program-error
253 :format-control "Multiple slots named ~S in DEFCLASS ~S."
254 :format-arguments (list name class-name))))))
256 (defun make-initfunction (initform)
257 (cond ((or (eq initform t)
258 (equal initform ''t))
259 '(function constantly-t))
260 ((or (eq initform nil)
261 (equal initform ''nil))
262 '(function constantly-nil))
263 ((or (eql initform 0)
264 (equal initform ''0))
265 '(function constantly-0))
267 (let ((entry (assoc initform *initfunctions-for-this-defclass*
270 (setq entry (list initform
272 `(function (lambda () ,initform))))
273 (push entry *initfunctions-for-this-defclass*))
276 (defun %compiler-defclass (name readers writers slots)
277 ;; ANSI says (Macro DEFCLASS, section 7.7) that DEFCLASS, if it
278 ;; "appears as a top level form, the compiler must make the class
279 ;; name be recognized as a valid type name in subsequent
280 ;; declarations (as for deftype) and be recognized as a valid class
281 ;; name for defmethod parameter specializers and for use as the
282 ;; :metaclass option of a subsequent defclass."
283 (preinform-compiler-about-class-type name)
284 (preinform-compiler-about-accessors readers writers slots))
286 (defun preinform-compiler-about-class-type (name)
287 ;; Unless the type system already has an actual type attached to
288 ;; NAME (in which case (1) writing a placeholder value over that
289 ;; actual type as a compile-time side-effect would probably be a bad
290 ;; idea and (2) anyway we don't need to modify it in order to make
291 ;; NAME be recognized as a valid type name)
292 (unless (info :type :kind name)
293 ;; Tell the compiler to expect a class with the given NAME, by
294 ;; writing a kind of minimal placeholder type information. This
295 ;; placeholder will be overwritten later when the class is defined.
296 (setf (info :type :kind name) :forthcoming-defclass-type))
299 (defun preinform-compiler-about-accessors (readers writers slots)
300 (flet ((inform (name type)
301 ;; FIXME: This matches what PROCLAIM FTYPE does, except
302 ;; that :WHERE-FROM is :DEFINED, not :DECLARED, and should
303 ;; probably be factored into a common function -- eg.
304 ;; (%proclaim-ftype name declared-or-defined).
305 (when (eq (info :function :where-from name) :assumed)
306 (proclaim-as-fun-name name)
307 (note-name-defined name :function)
308 (setf (info :function :where-from name) :defined
309 (info :function :type name) type))))
310 (let ((rtype (specifier-type '(function (t) t)))
311 (wtype (specifier-type '(function (t t) t))))
312 (dolist (reader readers)
313 (inform reader rtype))
314 (dolist (writer writers)
315 (inform writer wtype))
317 (inform (slot-reader-name slot) rtype)
318 (inform (slot-boundp-name slot) rtype)
319 (inform (slot-writer-name slot) wtype)))))
321 ;;; This is the early definition of LOAD-DEFCLASS. It just collects up
322 ;;; all the class definitions in a list. Later, in braid1.lisp, these
323 ;;; are actually defined.
325 ;;; Each entry in *EARLY-CLASS-DEFINITIONS* is an EARLY-CLASS-DEFINITION.
326 (defparameter *early-class-definitions* ())
328 (defun early-class-definition (class-name)
329 (or (find class-name *early-class-definitions* :key #'ecd-class-name)
330 (error "~S is not a class in *early-class-definitions*." class-name)))
332 (defun make-early-class-definition
333 (name source-location metaclass
334 superclass-names canonical-slots other-initargs)
335 (list 'early-class-definition
336 name source-location metaclass
337 superclass-names canonical-slots other-initargs))
339 (defun ecd-class-name (ecd) (nth 1 ecd))
340 (defun ecd-source-location (ecd) (nth 2 ecd))
341 (defun ecd-metaclass (ecd) (nth 3 ecd))
342 (defun ecd-superclass-names (ecd) (nth 4 ecd))
343 (defun ecd-canonical-slots (ecd) (nth 5 ecd))
344 (defun ecd-other-initargs (ecd) (nth 6 ecd))
346 (defvar *early-class-slots* nil)
348 (defun canonical-slot-name (canonical-slot)
349 (getf canonical-slot :name))
351 (defun early-class-slots (class-name)
352 (cdr (or (assoc class-name *early-class-slots*)
353 (let ((a (cons class-name
354 (mapcar #'canonical-slot-name
355 (early-collect-inheritance class-name)))))
356 (push a *early-class-slots*)
359 (defun early-class-size (class-name)
360 (length (early-class-slots class-name)))
362 (defun early-collect-inheritance (class-name)
363 ;;(declare (values slots cpl default-initargs direct-subclasses))
364 (let ((cpl (early-collect-cpl class-name)))
365 (values (early-collect-slots cpl)
367 (early-collect-default-initargs cpl)
369 (dolist (definition *early-class-definitions*)
370 (when (memq class-name (ecd-superclass-names definition))
371 (push (ecd-class-name definition) collect)))
372 (nreverse collect)))))
374 (defun early-collect-slots (cpl)
375 (let* ((definitions (mapcar #'early-class-definition cpl))
376 (super-slots (mapcar #'ecd-canonical-slots definitions))
377 (slots (apply #'append (reverse super-slots))))
379 (let ((name1 (canonical-slot-name s1)))
380 (dolist (s2 (cdr (memq s1 slots)))
381 (when (eq name1 (canonical-slot-name s2))
382 (error "More than one early class defines a slot with the~%~
383 name ~S. This can't work because the bootstrap~%~
384 object system doesn't know how to compute effective~%~
389 (defun early-collect-cpl (class-name)
391 (let* ((definition (early-class-definition c))
392 (supers (ecd-superclass-names definition)))
394 (apply #'append (mapcar #'early-collect-cpl supers))))))
395 (remove-duplicates (walk class-name) :from-end nil :test #'eq)))
397 (defun early-collect-default-initargs (cpl)
398 (let ((default-initargs ()))
399 (dolist (class-name cpl)
400 (let* ((definition (early-class-definition class-name))
401 (others (ecd-other-initargs definition)))
402 (loop (when (null others) (return nil))
403 (let ((initarg (pop others)))
404 (unless (eq initarg :direct-default-initargs)
405 (error "~@<The defclass option ~S is not supported by ~
406 the bootstrap object system.~:@>"
408 (setq default-initargs
409 (nconc default-initargs (reverse (pop others)))))))
410 (reverse default-initargs)))
412 (defun !bootstrap-slot-index (class-name slot-name)
413 (or (position slot-name (early-class-slots class-name))
414 (error "~S not found" slot-name)))
416 ;;; !BOOTSTRAP-GET-SLOT and !BOOTSTRAP-SET-SLOT are used to access and
417 ;;; change the values of slots during bootstrapping. During
418 ;;; bootstrapping, there are only two kinds of objects whose slots we
419 ;;; need to access, CLASSes and SLOT-DEFINITIONs. The first argument
420 ;;; to these functions tells whether the object is a CLASS or a
423 ;;; Note that the way this works it stores the slot in the same place
424 ;;; in memory that the full object system will expect to find it
425 ;;; later. This is critical to the bootstrapping process, the whole
426 ;;; changeover to the full object system is predicated on this.
428 ;;; One important point is that the layout of standard classes and
429 ;;; standard slots must be computed the same way in this file as it is
430 ;;; by the full object system later.
431 (defmacro !bootstrap-get-slot (type object slot-name)
432 `(clos-slots-ref (get-slots ,object)
433 (!bootstrap-slot-index ,type ,slot-name)))
434 (defun !bootstrap-set-slot (type object slot-name new-value)
435 (setf (!bootstrap-get-slot type object slot-name) new-value))
437 (defun early-class-name (class)
438 (!bootstrap-get-slot 'class class 'name))
440 (defun early-class-precedence-list (class)
441 (!bootstrap-get-slot 'pcl-class class '%class-precedence-list))
443 (defun early-class-name-of (instance)
444 (early-class-name (class-of instance)))
446 (defun early-class-slotds (class)
447 (!bootstrap-get-slot 'slot-class class 'slots))
449 (defun early-slot-definition-name (slotd)
450 (!bootstrap-get-slot 'standard-effective-slot-definition slotd 'name))
452 (defun early-slot-definition-location (slotd)
453 (!bootstrap-get-slot 'standard-effective-slot-definition slotd 'location))
455 (defun early-accessor-method-slot-name (method)
456 (!bootstrap-get-slot 'standard-accessor-method method 'slot-name))
458 (unless (fboundp 'class-name-of)
459 (setf (symbol-function 'class-name-of)
460 (symbol-function 'early-class-name-of)))
461 (unintern 'early-class-name-of)
463 (defun early-class-direct-subclasses (class)
464 (!bootstrap-get-slot 'class class 'direct-subclasses))
466 (declaim (notinline load-defclass))
467 (defun load-defclass (name metaclass supers canonical-slots canonical-options
468 readers writers slot-names source-location)
469 (%compiler-defclass name readers writers slot-names)
470 (setq supers (copy-tree supers)
471 canonical-slots (copy-tree canonical-slots)
472 canonical-options (copy-tree canonical-options))
474 (make-early-class-definition name
481 (find name *early-class-definitions* :key #'ecd-class-name)))
482 (setq *early-class-definitions*
483 (cons ecd (remove existing *early-class-definitions*)))