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
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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
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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*))))
77 ;; FIXME: (YUK!) Why do we do this? Because in order
78 ;; to make the defstruct form, we need to know what
79 ;; the accessors for the slots are, so we need already
80 ;; to have hooked into the CLOS machinery.
82 ;; There may be a better way to do this: it would
83 ;; involve knowing enough about PCL to ask "what will
84 ;; my slot names and accessors be"; failing this, we
85 ;; currently just evaluate the whole kaboodle, and
86 ;; then use CLASS-DIRECT-SLOTS. -- CSR, 2002-06-07
88 (let* ((include (or (and direct-superclasses
89 (fix-super (car direct-superclasses)))
90 (and (not (eq name 'structure-object))
91 *the-class-structure-object*)))
92 (defstruct-form (make-structure-class-defstruct-form
93 name (class-direct-slots (find-class name))
96 (eval-when (:compile-toplevel :load-toplevel :execute)
97 ,defstruct-form) ; really compile the defstruct-form
98 (eval-when (:compile-toplevel :load-toplevel :execute)
101 ;; By telling the type system at compile time about
102 ;; the existence of a class named NAME, we can avoid
103 ;; various bogus warnings about "type isn't defined yet"
104 ;; for code elsewhere in the same file which uses
105 ;; the name of the type.
107 ;; We only need to do this at compile time, because
108 ;; at load and execute time we write the actual
109 ;; full-blown class, so the "a class of this name is
110 ;; coming" note we write here would be irrelevant.
111 (eval-when (:compile-toplevel)
112 (%compiler-defclass ',name
113 ',*readers-for-this-defclass*
114 ',*writers-for-this-defclass*
115 ',*slot-names-for-this-defclass*))
116 (eval-when (:load-toplevel :execute)
117 ,defclass-form))))))))
119 (defun canonize-defclass-options (class-name options)
120 (macrolet ((assert-single (option)
122 (error "Multiple ~A options in DEFCLASS ~S."
123 ,(intern (string option) :keyword)
129 (dolist (option options)
130 (unless (listp option)
131 (error "~S is not a legal defclass option." option))
134 (assert-single metaclass)
135 (let ((maybe-metaclass (second option)))
136 (unless (and maybe-metaclass (legal-class-name-p maybe-metaclass))
137 (error "~@<The value of the :metaclass option (~S) ~
138 is not a legal class name.~:@>"
140 (setf metaclass maybe-metaclass)))
142 (assert-single default-initargs)
143 (let (initargs arg-names)
144 (doplist (key val) (cdr option)
145 (when (member key arg-names)
146 (error 'simple-program-error
147 :format-control "~@<Duplicate initialization argument ~
148 name ~S in :DEFAULT-INITARGS of ~
150 :format-arguments (list key class-name)))
152 (push ``(,',key ,,(make-initfunction val) ,',val) initargs))
153 (setf default-initargs t)
154 (push `(:direct-default-initargs (list ,@(nreverse initargs)))
157 (assert-single documentation)
158 (unless (stringp (second option))
159 (error "~S is not a legal :documentation value" (second option)))
160 (setf documentation t)
161 (push `(:documentation ,(second option)) canonized-options))
163 (push `(',(car option) ',(cdr option)) canonized-options))))
164 (values (or metaclass 'standard-class) (nreverse canonized-options)))))
166 (defun canonize-defclass-slots (class-name slots env)
167 (let (canonized-specs)
170 (setf spec (list spec)))
171 (when (and (cdr spec) (null (cddr spec)))
172 (error 'simple-program-error
173 :format-control "~@<in DEFCLASS ~S, the slot specification ~S ~
174 is invalid; the probable intended meaning may ~
175 be achieved by specifiying ~S instead.~:>"
176 :format-arguments (list class-name spec
177 `(,(car spec) :initform ,(cadr spec)))))
178 (let* ((name (car spec))
184 (unsupplied (list nil))
185 (initform unsupplied))
186 (check-slot-name-for-defclass name class-name env)
187 (push name *slot-names-for-this-defclass*)
188 (flet ((note-reader (x)
190 (error 'simple-program-error
191 :format-control "Slot reader name ~S for slot ~S in ~
192 DEFCLASS ~S is not a symbol."
193 :format-arguments (list x name class-name)))
195 (push x *readers-for-this-defclass*))
198 (push x *writers-for-this-defclass*)))
199 (doplist (key val) plist
201 (:accessor (note-reader val) (note-writer `(setf ,val)))
202 (:reader (note-reader val))
203 (:writer (note-writer val))
205 (unless (symbolp val)
206 (error 'simple-program-error
207 :format-control "Slot initarg name ~S for slot ~S in ~
208 DEFCLASS ~S is not a symbol."
209 :format-arguments (list val name class-name)))
212 (when (member key '(:initform :allocation :type :documentation))
213 (when (eq key :initform)
215 (when (get-properties others (list key))
216 (error 'simple-program-error
217 :format-control "Duplicate slot option ~S for slot ~
219 :format-arguments (list key name class-name))))
220 ;; For non-standard options multiple entries go in a list
221 (push val (getf others key))))))
222 ;; Unwrap singleton lists (AMOP 5.4.2)
223 (do ((head others (cddr head)))
225 (unless (cdr (second head))
226 (setf (second head) (car (second head)))))
227 (let ((canon `(:name ',name :readers ',readers :writers ',writers
228 :initargs ',initargs ',others)))
229 (push (if (eq initform unsupplied)
231 `(list* :initfunction ,(make-initfunction initform)
234 (nreverse canonized-specs)))
237 (defun check-slot-name-for-defclass (name class-name env)
238 (flet ((slot-name-illegal (reason)
239 (error 'simple-program-error
241 (format nil "~~@<In DEFCLASS ~~S, the slot name ~~S ~
243 :format-arguments (list class-name name))))
244 (cond ((not (symbolp name))
245 (slot-name-illegal "not a symbol"))
247 (slot-name-illegal "a keyword"))
248 ((constantp name env)
249 (slot-name-illegal "a constant"))
250 ((member name *slot-names-for-this-defclass*)
251 (error 'simple-program-error
252 :format-control "Multiple slots named ~S in DEFCLASS ~S."
253 :format-arguments (list name class-name))))))
255 (defun make-initfunction (initform)
256 (cond ((or (eq initform t)
257 (equal initform ''t))
258 '(function constantly-t))
259 ((or (eq initform nil)
260 (equal initform ''nil))
261 '(function constantly-nil))
262 ((or (eql initform 0)
263 (equal initform ''0))
264 '(function constantly-0))
266 (let ((entry (assoc initform *initfunctions-for-this-defclass*
269 (setq entry (list initform
271 `(function (lambda () ,initform))))
272 (push entry *initfunctions-for-this-defclass*))
275 (defun %compiler-defclass (name readers writers slots)
276 ;; ANSI says (Macro DEFCLASS, section 7.7) that DEFCLASS, if it
277 ;; "appears as a top level form, the compiler must make the class
278 ;; name be recognized as a valid type name in subsequent
279 ;; declarations (as for deftype) and be recognized as a valid class
280 ;; name for defmethod parameter specializers and for use as the
281 ;; :metaclass option of a subsequent defclass."
282 (preinform-compiler-about-class-type name)
283 (preinform-compiler-about-accessors readers writers slots))
285 (defun preinform-compiler-about-class-type (name)
286 ;; Unless the type system already has an actual type attached to
287 ;; NAME (in which case (1) writing a placeholder value over that
288 ;; actual type as a compile-time side-effect would probably be a bad
289 ;; idea and (2) anyway we don't need to modify it in order to make
290 ;; NAME be recognized as a valid type name)
291 (unless (info :type :kind name)
292 ;; Tell the compiler to expect a class with the given NAME, by
293 ;; writing a kind of minimal placeholder type information. This
294 ;; placeholder will be overwritten later when the class is defined.
295 (setf (info :type :kind name) :forthcoming-defclass-type))
298 (defun preinform-compiler-about-accessors (readers writers slots)
299 (flet ((inform (name type)
300 ;; FIXME: This matches what PROCLAIM FTYPE does, except
301 ;; that :WHERE-FROM is :DEFINED, not :DECLARED, and should
302 ;; probably be factored into a common function -- eg.
303 ;; (%proclaim-ftype name declared-or-defined).
304 (when (eq (info :function :where-from name) :assumed)
305 (proclaim-as-fun-name name)
306 (note-name-defined name :function)
307 (setf (info :function :where-from name) :defined
308 (info :function :type name) type))))
309 (let ((rtype (specifier-type '(function (t) t)))
310 (wtype (specifier-type '(function (t t) t))))
311 (dolist (reader readers)
312 (inform reader rtype))
313 (dolist (writer writers)
314 (inform writer wtype))
316 (inform (slot-reader-name slot) rtype)
317 (inform (slot-boundp-name slot) rtype)
318 (inform (slot-writer-name slot) wtype)))))
320 ;;; This is the early definition of LOAD-DEFCLASS. It just collects up
321 ;;; all the class definitions in a list. Later, in braid1.lisp, these
322 ;;; are actually defined.
324 ;;; Each entry in *EARLY-CLASS-DEFINITIONS* is an EARLY-CLASS-DEFINITION.
325 (defparameter *early-class-definitions* ())
327 (defun early-class-definition (class-name)
328 (or (find class-name *early-class-definitions* :key #'ecd-class-name)
329 (error "~S is not a class in *early-class-definitions*." class-name)))
331 (defun make-early-class-definition
332 (name source metaclass
333 superclass-names canonical-slots other-initargs)
334 (list 'early-class-definition
335 name source metaclass
336 superclass-names canonical-slots other-initargs))
338 (defun ecd-class-name (ecd) (nth 1 ecd))
339 (defun ecd-source (ecd) (nth 2 ecd))
340 (defun ecd-metaclass (ecd) (nth 3 ecd))
341 (defun ecd-superclass-names (ecd) (nth 4 ecd))
342 (defun ecd-canonical-slots (ecd) (nth 5 ecd))
343 (defun ecd-other-initargs (ecd) (nth 6 ecd))
345 (defvar *early-class-slots* nil)
347 (defun canonical-slot-name (canonical-slot)
348 (getf canonical-slot :name))
350 (defun early-class-slots (class-name)
351 (cdr (or (assoc class-name *early-class-slots*)
352 (let ((a (cons class-name
353 (mapcar #'canonical-slot-name
354 (early-collect-inheritance class-name)))))
355 (push a *early-class-slots*)
358 (defun early-class-size (class-name)
359 (length (early-class-slots class-name)))
361 (defun early-collect-inheritance (class-name)
362 ;;(declare (values slots cpl default-initargs direct-subclasses))
363 (let ((cpl (early-collect-cpl class-name)))
364 (values (early-collect-slots cpl)
366 (early-collect-default-initargs cpl)
368 (dolist (definition *early-class-definitions*)
369 (when (memq class-name (ecd-superclass-names definition))
370 (push (ecd-class-name definition) collect)))
371 (nreverse collect)))))
373 (defun early-collect-slots (cpl)
374 (let* ((definitions (mapcar #'early-class-definition cpl))
375 (super-slots (mapcar #'ecd-canonical-slots definitions))
376 (slots (apply #'append (reverse super-slots))))
378 (let ((name1 (canonical-slot-name s1)))
379 (dolist (s2 (cdr (memq s1 slots)))
380 (when (eq name1 (canonical-slot-name s2))
381 (error "More than one early class defines a slot with the~%~
382 name ~S. This can't work because the bootstrap~%~
383 object system doesn't know how to compute effective~%~
388 (defun early-collect-cpl (class-name)
390 (let* ((definition (early-class-definition c))
391 (supers (ecd-superclass-names definition)))
393 (apply #'append (mapcar #'early-collect-cpl supers))))))
394 (remove-duplicates (walk class-name) :from-end nil :test #'eq)))
396 (defun early-collect-default-initargs (cpl)
397 (let ((default-initargs ()))
398 (dolist (class-name cpl)
399 (let* ((definition (early-class-definition class-name))
400 (others (ecd-other-initargs definition)))
401 (loop (when (null others) (return nil))
402 (let ((initarg (pop others)))
403 (unless (eq initarg :direct-default-initargs)
404 (error "~@<The defclass option ~S is not supported by ~
405 the bootstrap object system.~:@>"
407 (setq default-initargs
408 (nconc default-initargs (reverse (pop others)))))))
409 (reverse default-initargs)))
411 (defun !bootstrap-slot-index (class-name slot-name)
412 (or (position slot-name (early-class-slots class-name))
413 (error "~S not found" slot-name)))
415 ;;; !BOOTSTRAP-GET-SLOT and !BOOTSTRAP-SET-SLOT are used to access and
416 ;;; change the values of slots during bootstrapping. During
417 ;;; bootstrapping, there are only two kinds of objects whose slots we
418 ;;; need to access, CLASSes and SLOT-DEFINITIONs. The first argument
419 ;;; to these functions tells whether the object is a CLASS or a
422 ;;; Note that the way this works it stores the slot in the same place
423 ;;; in memory that the full object system will expect to find it
424 ;;; later. This is critical to the bootstrapping process, the whole
425 ;;; changeover to the full object system is predicated on this.
427 ;;; One important point is that the layout of standard classes and
428 ;;; standard slots must be computed the same way in this file as it is
429 ;;; by the full object system later.
430 (defmacro !bootstrap-get-slot (type object slot-name)
431 `(clos-slots-ref (get-slots ,object)
432 (!bootstrap-slot-index ,type ,slot-name)))
433 (defun !bootstrap-set-slot (type object slot-name new-value)
434 (setf (!bootstrap-get-slot type object slot-name) new-value))
436 (defun early-class-name (class)
437 (!bootstrap-get-slot 'class class 'name))
439 (defun early-class-precedence-list (class)
440 (!bootstrap-get-slot 'pcl-class class 'class-precedence-list))
442 (defun early-class-name-of (instance)
443 (early-class-name (class-of instance)))
445 (defun early-class-slotds (class)
446 (!bootstrap-get-slot 'slot-class class 'slots))
448 (defun early-slot-definition-name (slotd)
449 (!bootstrap-get-slot 'standard-effective-slot-definition slotd 'name))
451 (defun early-slot-definition-location (slotd)
452 (!bootstrap-get-slot 'standard-effective-slot-definition slotd 'location))
454 (defun early-accessor-method-slot-name (method)
455 (!bootstrap-get-slot 'standard-accessor-method method 'slot-name))
457 (unless (fboundp 'class-name-of)
458 (setf (symbol-function 'class-name-of)
459 (symbol-function 'early-class-name-of)))
460 (unintern 'early-class-name-of)
462 (defun early-class-direct-subclasses (class)
463 (!bootstrap-get-slot 'class class 'direct-subclasses))
465 (declaim (notinline load-defclass))
466 (defun load-defclass (name metaclass supers canonical-slots canonical-options
467 readers writers slot-names)
468 (%compiler-defclass name readers writers slot-names)
469 (setq supers (copy-tree supers)
470 canonical-slots (copy-tree canonical-slots)
471 canonical-options (copy-tree canonical-options))
473 (make-early-class-definition name
480 (find name *early-class-definitions* :key #'ecd-class-name)))
481 (setq *early-class-definitions*
482 (cons ecd (remove existing *early-class-definitions*)))