0.6.11.35:
[sbcl.git] / src / pcl / braid.lisp
1 ;;;; bootstrapping the meta-braid
2 ;;;;
3 ;;;; The code in this file takes the early definitions that have been
4 ;;;; saved up and actually builds those class objects. This work is
5 ;;;; largely driven off of those class definitions, but the fact that
6 ;;;; STANDARD-CLASS is the class of all metaclasses in the braid is
7 ;;;; built into this code pretty deeply.
8
9 ;;;; This software is part of the SBCL system. See the README file for
10 ;;;; more information.
11
12 ;;;; This software is derived from software originally released by Xerox
13 ;;;; Corporation. Copyright and release statements follow. Later modifications
14 ;;;; to the software are in the public domain and are provided with
15 ;;;; absolutely no warranty. See the COPYING and CREDITS files for more
16 ;;;; information.
17
18 ;;;; copyright information from original PCL sources:
19 ;;;;
20 ;;;; Copyright (c) 1985, 1986, 1987, 1988, 1989, 1990 Xerox Corporation.
21 ;;;; All rights reserved.
22 ;;;;
23 ;;;; Use and copying of this software and preparation of derivative works based
24 ;;;; upon this software are permitted. Any distribution of this software or
25 ;;;; derivative works must comply with all applicable United States export
26 ;;;; control laws.
27 ;;;;
28 ;;;; This software is made available AS IS, and Xerox Corporation makes no
29 ;;;; warranty about the software, its performance or its conformity to any
30 ;;;; specification.
31
32 (in-package "SB-PCL")
33 \f
34 (defun allocate-standard-instance (wrapper
35                                    &optional (slots-init nil slots-init-p))
36   (let ((instance (%%allocate-instance--class))
37         (no-of-slots (wrapper-no-of-instance-slots wrapper)))
38     (setf (std-instance-wrapper instance) wrapper)
39     (setf (std-instance-slots instance)
40           (cond (slots-init-p
41                  ;; Inline the slots vector allocation and initialization.
42                  (let ((slots (make-array no-of-slots :initial-element 0)))
43                    (do ((rem-slots slots-init (rest rem-slots))
44                         (i 0 (1+ i)))
45                        ((>= i no-of-slots)) ;endp rem-slots))
46                      (declare (list rem-slots)
47                               (type index i))
48                      (setf (aref slots i) (first rem-slots)))
49                    slots))
50                 (t
51                  (make-array no-of-slots
52                              :initial-element +slot-unbound+))))
53     instance))
54
55 (defmacro allocate-funcallable-instance-slots (wrapper &optional
56                                                        slots-init-p slots-init)
57   `(let ((no-of-slots (wrapper-no-of-instance-slots ,wrapper)))
58      ,(if slots-init-p
59           `(if ,slots-init-p
60                (make-array no-of-slots :initial-contents ,slots-init)
61                (make-array no-of-slots :initial-element +slot-unbound+))
62           `(make-array no-of-slots :initial-element +slot-unbound+))))
63
64 (defun allocate-funcallable-instance (wrapper &optional
65                                               (slots-init nil slots-init-p))
66   (let ((fin (allocate-funcallable-instance-1)))
67     (set-funcallable-instance-function
68      fin
69      #'(sb-kernel:instance-lambda (&rest args)
70          (declare (ignore args))
71          (error "The function of the funcallable-instance ~S has not been set."
72                 fin)))
73     (setf (fsc-instance-wrapper fin) wrapper
74           (fsc-instance-slots fin) (allocate-funcallable-instance-slots
75                                     wrapper slots-init-p slots-init))
76     fin))
77
78 (defun allocate-structure-instance (wrapper &optional
79                                             (slots-init nil slots-init-p))
80   (let* ((class (wrapper-class wrapper))
81          (constructor (class-defstruct-constructor class)))
82     (if constructor
83         (let ((instance (funcall constructor))
84               (slots (class-slots class)))
85           (when slots-init-p
86             (dolist (slot slots)
87               (setf (slot-value-using-class class instance slot)
88                     (pop slots-init))))
89           instance)
90         (error "can't allocate an instance of class ~S" (class-name class)))))
91 \f
92 ;;;; BOOTSTRAP-META-BRAID
93 ;;;;
94 ;;;; This function builds the base metabraid from the early class definitions.
95 ;;;;
96 ;;;; FIXME: This, like lotso the other stuff in PCL, is not needed in target
97 ;;;; Lisp, only at bootstrap time. Perhaps we should do something kludgy like
98 ;;;; putting a special character (#\$, perhaps) at the beginning of each
99 ;;;; needed-only-at-bootstrap-time symbol and then UNINTERN them all once we're
100 ;;;; done bootstrapping?
101
102 (defmacro initial-classes-and-wrappers (&rest classes)
103   `(progn
104      ,@(mapcar #'(lambda (class)
105                    (let ((wr (intern (format nil "~A-WRAPPER" class)
106                                      *pcl-package*)))
107                      `(setf ,wr ,(if (eq class 'standard-generic-function)
108                                      '*sgf-wrapper*
109                                      `(boot-make-wrapper
110                                        (early-class-size ',class)
111                                        ',class))
112                             ,class (allocate-standard-instance
113                                     ,(if (eq class 'standard-generic-function)
114                                          'funcallable-standard-class-wrapper
115                                          'standard-class-wrapper))
116                             (wrapper-class ,wr) ,class
117                             (find-class ',class) ,class)))
118               classes)))
119
120 (defun !bootstrap-meta-braid ()
121   (let* ((name 'class)
122          (predicate-name (make-type-predicate-name name)))
123     (setf (gdefinition predicate-name)
124           #'(lambda (x) (declare (ignore x)) t))
125     (do-satisfies-deftype name predicate-name))
126   (let* ((*create-classes-from-internal-structure-definitions-p* nil)
127          std-class-wrapper std-class
128          standard-class-wrapper standard-class
129          funcallable-standard-class-wrapper funcallable-standard-class
130          slot-class-wrapper slot-class
131          built-in-class-wrapper built-in-class
132          structure-class-wrapper structure-class
133          standard-direct-slot-definition-wrapper
134          standard-direct-slot-definition
135          standard-effective-slot-definition-wrapper
136          standard-effective-slot-definition
137          class-eq-specializer-wrapper class-eq-specializer
138          standard-generic-function-wrapper standard-generic-function)
139     (initial-classes-and-wrappers
140      standard-class funcallable-standard-class
141      slot-class built-in-class structure-class std-class
142      standard-direct-slot-definition standard-effective-slot-definition
143      class-eq-specializer standard-generic-function)
144     ;; First, make a class metaobject for each of the early classes. For
145     ;; each metaobject we also set its wrapper. Except for the class T,
146     ;; the wrapper is always that of STANDARD-CLASS.
147     (dolist (definition *early-class-definitions*)
148       (let* ((name (ecd-class-name definition))
149              (meta (ecd-metaclass definition))
150              (wrapper (ecase meta
151                         (slot-class slot-class-wrapper)
152                         (std-class std-class-wrapper)
153                         (standard-class standard-class-wrapper)
154                         (funcallable-standard-class
155                          funcallable-standard-class-wrapper)
156                         (built-in-class built-in-class-wrapper)
157                         (structure-class structure-class-wrapper)))
158              (class (or (find-class name nil)
159                         (allocate-standard-instance wrapper))))
160         (when (or (eq meta 'standard-class)
161                   (eq meta 'funcallable-standard-class))
162           (inform-type-system-about-std-class name))
163         (setf (find-class name) class)))
164     (dolist (definition *early-class-definitions*)
165       (let ((name (ecd-class-name definition))
166             (meta (ecd-metaclass definition))
167             (source (ecd-source definition))
168             (direct-supers (ecd-superclass-names definition))
169             (direct-slots  (ecd-canonical-slots definition))
170             (other-initargs (ecd-other-initargs definition)))
171         (let ((direct-default-initargs
172                (getf other-initargs :direct-default-initargs)))
173           (multiple-value-bind (slots cpl default-initargs direct-subclasses)
174               (early-collect-inheritance name)
175             (let* ((class (find-class name))
176                    (wrapper (cond ((eq class slot-class)
177                                    slot-class-wrapper)
178                                   ((eq class std-class)
179                                    std-class-wrapper)
180                                   ((eq class standard-class)
181                                    standard-class-wrapper)
182                                   ((eq class funcallable-standard-class)
183                                    funcallable-standard-class-wrapper)
184                                   ((eq class standard-direct-slot-definition)
185                                    standard-direct-slot-definition-wrapper)
186                                   ((eq class
187                                        standard-effective-slot-definition)
188                                    standard-effective-slot-definition-wrapper)
189                                   ((eq class built-in-class)
190                                    built-in-class-wrapper)
191                                   ((eq class structure-class)
192                                    structure-class-wrapper)
193                                   ((eq class class-eq-specializer)
194                                    class-eq-specializer-wrapper)
195                                   ((eq class standard-generic-function)
196                                    standard-generic-function-wrapper)
197                                   (t
198                                    (boot-make-wrapper (length slots) name))))
199                    (proto nil))
200               (when (eq name t) (setq *the-wrapper-of-t* wrapper))
201               (set (intern (format nil "*THE-CLASS-~A*" (symbol-name name))
202                            *pcl-package*)
203                    class)
204               (dolist (slot slots)
205                 (unless (eq (getf slot :allocation :instance) :instance)
206                   (error "Slot allocation ~S is not supported in bootstrap.")))
207
208               (when (typep wrapper 'wrapper)
209                 (setf (wrapper-instance-slots-layout wrapper)
210                       (mapcar #'canonical-slot-name slots))
211                 (setf (wrapper-class-slots wrapper)
212                       ()))
213
214               (setq proto (if (eq meta 'funcallable-standard-class)
215                               (allocate-funcallable-instance wrapper)
216                               (allocate-standard-instance wrapper)))
217
218               (setq direct-slots
219                     (!bootstrap-make-slot-definitions
220                      name class direct-slots
221                      standard-direct-slot-definition-wrapper nil))
222               (setq slots
223                     (!bootstrap-make-slot-definitions
224                      name class slots
225                      standard-effective-slot-definition-wrapper t))
226
227               (case meta
228                 ((std-class standard-class funcallable-standard-class)
229                  (!bootstrap-initialize-class
230                   meta
231                   class name class-eq-specializer-wrapper source
232                   direct-supers direct-subclasses cpl wrapper proto
233                   direct-slots slots direct-default-initargs default-initargs))
234                 (built-in-class         ; *the-class-t*
235                  (!bootstrap-initialize-class
236                   meta
237                   class name class-eq-specializer-wrapper source
238                   direct-supers direct-subclasses cpl wrapper proto))
239                 (slot-class             ; *the-class-slot-object*
240                  (!bootstrap-initialize-class
241                   meta
242                   class name class-eq-specializer-wrapper source
243                   direct-supers direct-subclasses cpl wrapper proto))
244                 (structure-class        ; *the-class-structure-object*
245                  (!bootstrap-initialize-class
246                   meta
247                   class name class-eq-specializer-wrapper source
248                   direct-supers direct-subclasses cpl wrapper))))))))
249
250     (let* ((smc-class (find-class 'standard-method-combination))
251            (smc-wrapper (!bootstrap-get-slot 'standard-class
252                                              smc-class
253                                              'wrapper))
254            (smc (allocate-standard-instance smc-wrapper)))
255       (flet ((set-slot (name value)
256                (!bootstrap-set-slot 'standard-method-combination
257                                     smc
258                                     name
259                                     value)))
260         (set-slot 'source *load-truename*)
261         (set-slot 'type 'standard)
262         (set-slot 'documentation "The standard method combination.")
263         (set-slot 'options ()))
264       (setq *standard-method-combination* smc))))
265
266 ;;; Initialize a class metaobject.
267 (defun !bootstrap-initialize-class
268        (metaclass-name class name
269         class-eq-wrapper source direct-supers direct-subclasses cpl wrapper
270         &optional
271         proto direct-slots slots direct-default-initargs default-initargs)
272   (flet ((classes (names) (mapcar #'find-class names))
273          (set-slot (slot-name value)
274            (!bootstrap-set-slot metaclass-name class slot-name value)))
275     (set-slot 'name name)
276     (set-slot 'source source)
277     (set-slot 'type (if (eq class (find-class t))
278                         t
279                         ;; FIXME: Could this just be CLASS instead
280                         ;; of `(CLASS ,CLASS)? If not, why not?
281                         ;; (See also similar expression in 
282                         ;; SHARED-INITIALIZE :BEFORE (CLASS).)
283                         `(class ,class)))
284     (set-slot 'class-eq-specializer
285               (let ((spec (allocate-standard-instance class-eq-wrapper)))
286                 (!bootstrap-set-slot 'class-eq-specializer spec 'type
287                                      `(class-eq ,class))
288                 (!bootstrap-set-slot 'class-eq-specializer spec 'object
289                                      class)
290                 spec))
291     (set-slot 'class-precedence-list (classes cpl))
292     (set-slot 'can-precede-list (classes (cdr cpl)))
293     (set-slot 'incompatible-superclass-list nil)
294     (set-slot 'direct-superclasses (classes direct-supers))
295     (set-slot 'direct-subclasses (classes direct-subclasses))
296     (set-slot 'direct-methods (cons nil nil))
297     (set-slot 'wrapper wrapper)
298     (set-slot 'predicate-name (or (cadr (assoc name *early-class-predicates*))
299                                   (make-class-predicate-name name)))
300     (set-slot 'plist
301               `(,@(and direct-default-initargs
302                        `(direct-default-initargs ,direct-default-initargs))
303                 ,@(and default-initargs
304                        `(default-initargs ,default-initargs))))
305     (when (memq metaclass-name '(standard-class funcallable-standard-class
306                                  structure-class slot-class std-class))
307       (set-slot 'direct-slots direct-slots)
308       (set-slot 'slots slots)
309       (set-slot 'initialize-info nil))
310     (if (eq metaclass-name 'structure-class)
311         (let ((constructor-sym '|STRUCTURE-OBJECT class constructor|))
312           (set-slot 'predicate-name (or (cadr (assoc name
313                                                      *early-class-predicates*))
314                                         (make-class-predicate-name name)))
315           (set-slot 'defstruct-form
316                     `(defstruct (structure-object (:constructor
317                                                    ,constructor-sym)
318                                                   (:copier nil))))
319           (set-slot 'defstruct-constructor constructor-sym)
320           (set-slot 'from-defclass-p t)
321           (set-slot 'plist nil)
322           (set-slot 'prototype (funcall constructor-sym)))
323         (set-slot 'prototype (or proto (allocate-standard-instance wrapper))))
324     class))
325
326 (defun !bootstrap-make-slot-definitions (name class slots wrapper effective-p)
327   (let ((index -1))
328     (mapcar (lambda (slot)
329               (incf index)
330               (!bootstrap-make-slot-definition
331                name class slot wrapper effective-p index))
332             slots)))
333
334 (defun !bootstrap-make-slot-definition
335     (name class slot wrapper effective-p index)
336   (let* ((slotd-class-name (if effective-p
337                                'standard-effective-slot-definition
338                                'standard-direct-slot-definition))
339          (slotd (allocate-standard-instance wrapper))
340          (slot-name (getf slot :name)))
341     (flet ((get-val (name) (getf slot name))
342            (set-val (name val)
343                     (!bootstrap-set-slot slotd-class-name slotd name val)))
344       (set-val 'name         slot-name)
345       (set-val 'initform     (get-val :initform))
346       (set-val 'initfunction (get-val :initfunction))
347       (set-val 'initargs     (get-val :initargs))
348       (set-val 'readers      (get-val :readers))
349       (set-val 'writers      (get-val :writers))
350       (set-val 'allocation   :instance)
351       (set-val 'type         (or (get-val :type) t))
352       (set-val 'documentation (or (get-val :documentation) ""))
353       (set-val 'class   class)
354       (when effective-p
355         (set-val 'location index)
356         (let ((fsc-p nil))
357           (set-val 'reader-function (make-optimized-std-reader-method-function
358                                      fsc-p slot-name index))
359           (set-val 'writer-function (make-optimized-std-writer-method-function
360                                      fsc-p slot-name index))
361           (set-val 'boundp-function (make-optimized-std-boundp-method-function
362                                      fsc-p slot-name index)))
363         (set-val 'accessor-flags 7)
364         (let ((table (or (gethash slot-name *name->class->slotd-table*)
365                          (setf (gethash slot-name *name->class->slotd-table*)
366                                (make-hash-table :test 'eq :size 5)))))
367           (setf (gethash class table) slotd)))
368       (when (and (eq name 'standard-class)
369                  (eq slot-name 'slots) effective-p)
370         (setq *the-eslotd-standard-class-slots* slotd))
371       (when (and (eq name 'funcallable-standard-class)
372                  (eq slot-name 'slots) effective-p)
373         (setq *the-eslotd-funcallable-standard-class-slots* slotd))
374       slotd)))
375
376 (defun !bootstrap-accessor-definitions (early-p)
377   (let ((*early-p* early-p))
378     (dolist (definition *early-class-definitions*)
379       (let ((name (ecd-class-name definition))
380             (meta (ecd-metaclass definition)))
381         (unless (eq meta 'built-in-class)
382           (let ((direct-slots  (ecd-canonical-slots definition)))
383             (dolist (slotd direct-slots)
384               (let ((slot-name (getf slotd :name))
385                     (readers (getf slotd :readers))
386                     (writers (getf slotd :writers)))
387                 (!bootstrap-accessor-definitions1
388                  name
389                  slot-name
390                  readers
391                  writers
392                  nil)
393                 (!bootstrap-accessor-definitions1
394                  'slot-object
395                  slot-name
396                  (list (slot-reader-symbol slot-name))
397                  (list (slot-writer-symbol slot-name))
398                  (list (slot-boundp-symbol slot-name)))))))))))
399
400 (defun !bootstrap-accessor-definition (class-name accessor-name slot-name type)
401   (multiple-value-bind (accessor-class make-method-function arglist specls doc)
402       (ecase type
403         (reader (values 'standard-reader-method
404                         #'make-std-reader-method-function
405                         (list class-name)
406                         (list class-name)
407                         "automatically generated reader method"))
408         (writer (values 'standard-writer-method
409                         #'make-std-writer-method-function
410                         (list 'new-value class-name)
411                         (list t class-name)
412                         "automatically generated writer method"))
413         (boundp (values 'standard-boundp-method
414                         #'make-std-boundp-method-function
415                         (list class-name)
416                         (list class-name)
417                         "automatically generated boundp method")))
418     (let ((gf (ensure-generic-function accessor-name)))
419       (if (find specls (early-gf-methods gf)
420                 :key #'early-method-specializers
421                 :test 'equal)
422           (unless (assoc accessor-name *!generic-function-fixups*
423                          :test #'equal)
424             (update-dfun gf))
425           (add-method gf
426                       (make-a-method accessor-class
427                                      ()
428                                      arglist specls
429                                      (funcall make-method-function
430                                               class-name slot-name)
431                                      doc
432                                      slot-name))))))
433
434 (defun !bootstrap-accessor-definitions1 (class-name
435                                         slot-name
436                                         readers
437                                         writers
438                                         boundps)
439   (flet ((do-reader-definition (reader)
440            (!bootstrap-accessor-definition class-name
441                                            reader
442                                            slot-name
443                                            'reader))
444          (do-writer-definition (writer)
445            (!bootstrap-accessor-definition class-name
446                                            writer
447                                            slot-name
448                                            'writer))
449          (do-boundp-definition (boundp)
450            (!bootstrap-accessor-definition class-name
451                                            boundp
452                                            slot-name
453                                            'boundp)))
454     (dolist (reader readers) (do-reader-definition reader))
455     (dolist (writer writers) (do-writer-definition writer))
456     (dolist (boundp boundps) (do-boundp-definition boundp))))
457
458 (defun !bootstrap-class-predicates (early-p)
459   (let ((*early-p* early-p))
460     (dolist (definition *early-class-definitions*)
461       (let* ((name (ecd-class-name definition))
462              (class (find-class name)))
463         (setf (find-class-predicate name)
464               (make-class-predicate class (class-predicate-name class)))))))
465
466 (defun !bootstrap-built-in-classes ()
467
468   ;; First make sure that all the supers listed in
469   ;; *BUILT-IN-CLASS-LATTICE* are themselves defined by
470   ;; *BUILT-IN-CLASS-LATTICE*. This is just to check for typos and
471   ;; other sorts of brainos.
472   (dolist (e *built-in-classes*)
473     (dolist (super (cadr e))
474       (unless (or (eq super t)
475                   (assq super *built-in-classes*))
476         (error "in *BUILT-IN-CLASSES*: ~S has ~S as a super,~%~
477                 but ~S is not itself a class in *BUILT-IN-CLASSES*."
478                (car e) super super))))
479
480   ;; In the first pass, we create a skeletal object to be bound to the
481   ;; class name.
482   (let* ((built-in-class (find-class 'built-in-class))
483          (built-in-class-wrapper (class-wrapper built-in-class)))
484     (dolist (e *built-in-classes*)
485       (let ((class (allocate-standard-instance built-in-class-wrapper)))
486         (setf (find-class (car e)) class))))
487
488   ;; In the second pass, we initialize the class objects.
489   (let ((class-eq-wrapper (class-wrapper (find-class 'class-eq-specializer))))
490     (dolist (e *built-in-classes*)
491       (destructuring-bind (name supers subs cpl prototype) e
492         (let* ((class (find-class name))
493                (lclass (cl:find-class name))
494                (wrapper (sb-kernel:class-layout lclass)))
495           (set (get-built-in-class-symbol name) class)
496           (set (get-built-in-wrapper-symbol name) wrapper)
497           (setf (sb-kernel:class-pcl-class lclass) class)
498
499           (!bootstrap-initialize-class 'built-in-class class
500                                        name class-eq-wrapper nil
501                                        supers subs
502                                        (cons name cpl)
503                                        wrapper prototype)))))
504
505   (dolist (e *built-in-classes*)
506     (let* ((name (car e))
507            (class (find-class name)))
508       (setf (find-class-predicate name)
509             (make-class-predicate class (class-predicate-name class))))))
510 \f
511 (defmacro wrapper-of-macro (x)
512   `(sb-kernel:layout-of ,x))
513
514 (defun class-of (x)
515   (wrapper-class* (wrapper-of-macro x)))
516
517 ;;; FIXME: We probably don't need both WRAPPER-OF and WRAPPER-OF-MACRO.
518 #-sb-fluid (declaim (inline wrapper-of))
519 (defun wrapper-of (x)
520   (wrapper-of-macro x))
521
522 (defvar *find-structure-class* nil)
523
524 (defun eval-form (form)
525   #'(lambda () (eval form)))
526
527 (defun slot-initargs-from-structure-slotd (slotd)
528   `(:name ,(structure-slotd-name slotd)
529     :defstruct-accessor-symbol ,(structure-slotd-accessor-symbol slotd)
530     :internal-reader-function ,(structure-slotd-reader-function slotd)
531     :internal-writer-function ,(structure-slotd-writer-function slotd)
532     :type ,(or (structure-slotd-type slotd) t)
533     :initform ,(structure-slotd-init-form slotd)
534     :initfunction ,(eval-form (structure-slotd-init-form slotd))))
535
536 (defun find-structure-class (symbol)
537   (if (structure-type-p symbol)
538       (unless (eq *find-structure-class* symbol)
539         (let ((*find-structure-class* symbol))
540           (ensure-class symbol
541                         :metaclass 'structure-class
542                         :name symbol
543                         :direct-superclasses
544                         (cond ;; Handle our CMU-CL-ish structure-based
545                               ;; conditions.
546                               ((cl:subtypep symbol 'condition)
547                                (mapcar #'cl:class-name
548                                        (sb-kernel:class-direct-superclasses
549                                         (cl:find-class symbol))))
550                               ;; a hack to add the STREAM class as a
551                               ;; mixin to the LISP-STREAM class.
552                               ((eq symbol 'sb-kernel:lisp-stream)
553                                '(structure-object stream))
554                               ((structure-type-included-type-name symbol)
555                                (list (structure-type-included-type-name
556                                       symbol))))
557                         :direct-slots
558                         (mapcar #'slot-initargs-from-structure-slotd
559                                 (structure-type-slot-description-list
560                                  symbol)))))
561       (error "~S is not a legal structure class name." symbol)))
562 \f
563 (defun make-class-predicate (class name)
564   (let* ((gf (ensure-generic-function name))
565          (mlist (if (eq *boot-state* 'complete)
566                     (generic-function-methods gf)
567                     (early-gf-methods gf))))
568     (unless mlist
569       (unless (eq class *the-class-t*)
570         (let* ((default-method-function #'constantly-nil)
571                (default-method-initargs (list :function
572                                               default-method-function))
573                (default-method (make-a-method 'standard-method
574                                               ()
575                                               (list 'object)
576                                               (list *the-class-t*)
577                                               default-method-initargs
578                                               "class predicate default method")))
579           (setf (method-function-get default-method-function :constant-value)
580                 nil)
581           (add-method gf default-method)))
582       (let* ((class-method-function #'constantly-t)
583              (class-method-initargs (list :function
584                                           class-method-function))
585              (class-method (make-a-method 'standard-method
586                                           ()
587                                           (list 'object)
588                                           (list class)
589                                           class-method-initargs
590                                           "class predicate class method")))
591         (setf (method-function-get class-method-function :constant-value) t)
592         (add-method gf class-method)))
593     gf))
594
595 ;;; Set the inherits from CPL, and register the layout. This actually
596 ;;; installs the class in the Lisp type system.
597 (defun update-lisp-class-layout (class layout)
598   (let ((lclass (sb-kernel:layout-class layout)))
599     (unless (eq (sb-kernel:class-layout lclass) layout)
600       (setf (sb-kernel:layout-inherits layout)
601             (map 'vector #'class-wrapper
602                  (reverse (rest (class-precedence-list class)))))
603       (sb-kernel:register-layout layout :invalidate nil)
604
605       ;; Subclasses of formerly forward-referenced-class may be
606       ;; unknown to CL:FIND-CLASS and also anonymous. This
607       ;; functionality moved here from (SETF FIND-CLASS).
608       (let ((name (class-name class)))
609         (setf (cl:find-class name) lclass
610               ;; FIXME: It's nasty to use double colons. Perhaps the
611               ;; best way to fix this is not to export CLASS-%NAME
612               ;; from SB-KERNEL, but instead to move the whole
613               ;; UPDATE-LISP-CLASS-LAYOUT function to SB-KERNEL, and
614               ;; export it. (since it's also nasty for us to be
615               ;; reaching into %KERNEL implementation details my
616               ;; messing with raw CLASS-%NAME)
617               (sb-kernel::class-%name lclass) name)))))
618
619 (clrhash *find-class*)
620 (!bootstrap-meta-braid)
621 (!bootstrap-accessor-definitions t)
622 (!bootstrap-class-predicates t)
623 (!bootstrap-accessor-definitions nil)
624 (!bootstrap-class-predicates nil)
625 (!bootstrap-built-in-classes)
626
627 (dohash (name x *find-class*)
628         (let* ((class (find-class-from-cell name x))
629                (layout (class-wrapper class))
630                (lclass (sb-kernel:layout-class layout))
631                (lclass-pcl-class (sb-kernel:class-pcl-class lclass))
632                (olclass (cl:find-class name nil)))
633           (if lclass-pcl-class
634               (aver (eq class lclass-pcl-class))
635               (setf (sb-kernel:class-pcl-class lclass) class))
636
637           (update-lisp-class-layout class layout)
638
639           (cond (olclass
640                  (aver (eq lclass olclass)))
641                 (t
642                  (setf (cl:find-class name) lclass)))))
643
644 (setq *boot-state* 'braid)
645
646 (defmethod no-applicable-method (generic-function &rest args)
647   (error "~@<There is no matching method for the generic function ~2I~_~S~
648           ~I~_when called with arguments ~2I~_~S.~:>"
649          generic-function
650          args))