1;;;; permutation vectors
2
3;;;; This software is part of the SBCL system. See the README file for
4;;;; more information.
5
6;;;; This software is derived from software originally released by Xerox
7;;;; Corporation. Copyright and release statements follow. Later modifications
8;;;; to the software are in the public domain and are provided with
9;;;; absolutely no warranty. See the COPYING and CREDITS files for more
10;;;; information.
11
12;;;; copyright information from original PCL sources:
13;;;;
14;;;; Copyright (c) 1985, 1986, 1987, 1988, 1989, 1990 Xerox Corporation.
15;;;; All rights reserved.
16;;;;
17;;;; Use and copying of this software and preparation of derivative works based
18;;;; upon this software are permitted. Any distribution of this software or
19;;;; derivative works must comply with all applicable United States export
20;;;; control laws.
21;;;;
22;;;; This software is made available AS IS, and Xerox Corporation makes no
23;;;; warranty about the software, its performance or its conformity to any
24;;;; specification.
25
26(in-package "SB-PCL")
27
28;;;; Up to 1.0.9.24 SBCL used to have a sketched out implementation
29;;;; for optimizing GF calls inside method bodies using a PV approach,
30;;;; inherited from the original PCL. This was never completed, and
31;;;; was removed at that point to make the code easier to understand
32;;;; -- but:
33;;;;
34;;;; FIXME: It would be possible to optimize GF calls inside method
35;;;; bodies using permutation vectors: if all the arguments to the
36;;;; GF are specializers parameters, we can assign a permutation index
37;;;; to each such (GF . ARGS) tuple inside a method body, and use this
38;;;; to cache effective method functions.
39
40(declaim (inline make-pv-table))
41(defstruct (pv-table (:predicate pv-tablep)
42                     (:copier nil))
43  (cache nil :type (or cache null))
44  (pv-size 0 :type fixnum)
45  (slot-name-lists nil :type list))
46
47(defun make-pv-table-type-declaration (var)
48  `(type pv-table ,var))
49
50;;; Used for interning parts of SLOT-NAME-LISTS, as part of
51;;; PV-TABLE interning -- just to save space.
52(defvar *slot-name-lists* (make-hash-table :test 'equal))
53
54;;; Used for interning PV-TABLES, keyed by the SLOT-NAME-LISTS
55;;; used.
56(defvar *pv-tables* (make-hash-table :test 'equal))
57
58;;; ...and one lock to rule them. Lock because for certain (rare)
59;;; cases this lock might be grabbed in the course of method dispatch
60;;; -- and mostly this is already under the *world-lock*
61(defvar *pv-lock*
62  (sb-thread:make-mutex :name "pv table index lock"))
63
64(defun intern-pv-table (&key slot-name-lists)
65  (flet ((intern-slot-names (slot-names)
66           (or (gethash slot-names *slot-name-lists*)
67               (setf (gethash slot-names *slot-name-lists*) slot-names)))
68         (%intern-pv-table (snl)
69           (or (gethash snl *pv-tables*)
70               (setf (gethash snl *pv-tables*)
71                     (make-pv-table :slot-name-lists snl
72                                    :pv-size (* 2 (reduce #'+ snl :key #'length)))))))
73    (sb-thread:with-mutex (*pv-lock*)
74      (%intern-pv-table (mapcar #'intern-slot-names slot-name-lists)))))
75
76(defun use-standard-slot-access-p (class slot-name type)
77  (or (not (eq **boot-state** 'complete))
78      (and (standard-class-p class)
79           (let ((slotd (find-slot-definition class slot-name)))
80             (and slotd
81                  (slot-accessor-std-p slotd type))))))
82
83(defun slot-missing-info (class slot-name)
84  (make-slot-info
85   :reader (lambda (object)
86             (values (slot-missing class object slot-name 'slot-value)))
87   :boundp (lambda (object)
88             (and (slot-missing class object slot-name 'slot-boundp) t))
89   :writer (lambda (new-value object)
90             (slot-missing class object slot-name 'setf new-value)
91             new-value)))
92
93(defun compute-pv (slot-name-lists wrappers)
94  (let ((wrappers (ensure-list wrappers)))
95    (collect ((pv))
96      (dolist (slot-names slot-name-lists)
97        (when slot-names
98          (let* ((wrapper (pop wrappers))
99                 (std-p (layout-for-std-class-p wrapper))
100                 (class (wrapper-class* wrapper)))
101            (dolist (slot-name slot-names)
102              (destructuring-bind (location . info)
103                  (or (find-slot-cell wrapper slot-name)
104                      (cons nil (slot-missing-info class slot-name)))
105                (unless info
106                  (bug "No SLOT-INFO for ~S in ~S" slot-name class))
107                (pv (when (and std-p (use-standard-slot-access-p class slot-name 'all))
108                      location))
109                (pv info))))))
110      (coerce (pv) 'vector))))
111
112(defun pv-table-lookup (pv-table pv-wrappers)
113  (let* ((slot-name-lists (pv-table-slot-name-lists pv-table))
114         (cache (or (pv-table-cache pv-table)
115                    (setf (pv-table-cache pv-table)
116                          (make-cache :key-count (- (length slot-name-lists)
117                                                    (count nil slot-name-lists))
118                                      :value t
119                                      :size 2)))))
120    (multiple-value-bind (hitp value) (probe-cache cache pv-wrappers)
121      (if hitp
122          value
123          (let* ((pv (compute-pv slot-name-lists pv-wrappers))
124                 (new-cache (fill-cache cache pv-wrappers pv)))
125            ;; This is safe: if another thread races us here the loser just
126            ;; misses the next time as well.
127            (unless (eq new-cache cache)
128              (setf (pv-table-cache pv-table) new-cache))
129            pv)))))
130
131(defun make-pv-type-declaration (var)
132  `(type simple-vector ,var))
133
134;;; Sometimes we want to finalize if we can, but it's OK if
135;;; we can't.
136(defun try-finalize-inheritance (class)
137  (unless (typep class 'forward-referenced-class)
138    (when (every (lambda (super)
139                   (or (eq super class)
140                       (class-finalized-p super)
141                       (try-finalize-inheritance super)))
142                 (class-direct-superclasses class))
143      (finalize-inheritance class)
144      t)))
145
146(declaim (ftype (sfunction (class) class) ensure-class-finalized)
147         (maybe-inline ensure-class-finalized))
148(defun ensure-class-finalized (class)
149  (unless (class-finalized-p class)
150    (finalize-inheritance class))
151  class)
152
153(defun can-optimize-access (form required-parameters env)
154  (destructuring-bind (op var-form slot-name-form &optional new-value) form
155    (let ((type (ecase op
156                  (slot-value 'reader)
157                  (set-slot-value 'writer)
158                  (slot-boundp 'boundp)))
159          (var (extract-the var-form))
160          (slot-name (constant-form-value slot-name-form env)))
161      (when (and (symbolp var) (not (var-special-p var env)))
162        (let* ((rebound? (caddr (var-declaration '%variable-rebinding var env)))
163               (parameter-or-nil (car (memq (or rebound? var)
164                                            required-parameters))))
165          (when parameter-or-nil
166            (let* ((class-name (caddr (var-declaration '%class
167                                                       parameter-or-nil
168                                                       env)))
169                   (class (find-class class-name nil)))
170              (cond ((not (eq **boot-state** 'complete))
171                     (setq class nil))
172                    ((and class (not (class-finalized-p class)))
173                     ;; The class itself is never forward-referenced
174                     ;; here, but its superclasses may be.
175                     (unless (try-finalize-inheritance class)
176                       (when (boundp 'sb-c:*lexenv*)
177                         (sb-c:compiler-notify
178                          "~@<Cannot optimize slot access, inheritance of ~S is not ~
179                           yet finalizable due to forward-referenced superclasses:~
180                           ~%  ~S~:@>"
181                          class form))
182                       (setf class nil))))
183              (when (and class-name (not (eq class-name t)))
184                (when (not (and class
185                                (memq *the-class-structure-object*
186                                      (class-precedence-list class))))
187                  (aver type)
188                  (values (cons parameter-or-nil (or class class-name))
189                          slot-name
190                          new-value))))))))))
191
192;;; Check whether the binding of the named variable is modified in the
193;;; method body.
194(defun parameter-modified-p (parameter-name env)
195  (let ((modified-variables (%macroexpand '%parameter-binding-modified env)))
196    (memq parameter-name modified-variables)))
197
198(defun optimize-slot-value (form slots required-parameters env)
199  (multiple-value-bind (sparameter slot-name)
200      (can-optimize-access form required-parameters env)
201    (if sparameter
202        (let ((optimized-form
203               (optimize-instance-access slots :read sparameter
204                                         slot-name nil)))
205          ;; We don't return the optimized form directly, since there's
206          ;; still a chance that we'll find out later on that the
207          ;; optimization should not have been done, for example due to
208          ;; the walker encountering a SETQ on SPARAMETER later on in
209          ;; the body [ see for example clos.impure.lisp test with :name
210          ;; ((:setq :method-parameter) slot-value)) ]. Instead we defer
211          ;; the decision until the compiler macroexpands
212          ;; OPTIMIZED-SLOT-VALUE.
213          ;;
214          ;; Note that we must still call OPTIMIZE-INSTANCE-ACCESS at
215          ;; this point (instead of when expanding
216          ;; OPTIMIZED-SLOT-VALUE), since it mutates the structure of
217          ;; SLOTS. If that mutation isn't done during the walking,
218          ;; MAKE-METHOD-LAMBDA-INTERNAL won't wrap a correct PV-BINDING
219          ;; form around the body, and compilation will fail.  -- JES,
220          ;; 2006-09-18
221          `(optimized-slot-value ,form ,(car sparameter) ,optimized-form))
222        `(accessor-slot-value ,@(cdr form)))))
223
224(defmacro optimized-slot-value (form parameter-name optimized-form
225                                &environment env)
226  ;; Either use OPTIMIZED-FORM or fall back to the safe
227  ;; ACCESSOR-SLOT-VALUE.
228  (if (parameter-modified-p parameter-name env)
229      `(accessor-slot-value ,@(cdr form))
230      optimized-form))
231
232(defun optimize-set-slot-value (form slots required-parameters env)
233  (multiple-value-bind (sparameter slot-name new-value)
234      (can-optimize-access form required-parameters env)
235    (if sparameter
236        (let ((optimized-form
237               (optimize-instance-access slots :write sparameter
238                                         slot-name new-value (safe-code-p env))))
239             ;; See OPTIMIZE-SLOT-VALUE
240             `(optimized-set-slot-value ,form ,(car sparameter) ,optimized-form))
241           `(accessor-set-slot-value ,@(cdr form)))))
242
243(defmacro optimized-set-slot-value (form parameter-name optimized-form
244                                    &environment env)
245  (cond ((parameter-modified-p parameter-name env)
246         ;; ACCESSOR-SET-SLOT-VALUE doesn't do type-checking,
247         ;; so we need to use SAFE-SET-SLOT-VALUE.
248         (if (safe-code-p env)
249             `(safe-set-slot-value ,@(cdr form)))
250             `(accessor-set-slot-value ,@(cdr form)))
251        (t
252         optimized-form)))
253
254(defun optimize-slot-boundp (form slots required-parameters env)
255  (multiple-value-bind (sparameter slot-name)
256      (can-optimize-access form required-parameters env)
257    (if sparameter
258        (let ((optimized-form
259               (optimize-instance-access slots :boundp sparameter
260                                         slot-name nil)))
261          ;; See OPTIMIZE-SLOT-VALUE
262          `(optimized-slot-boundp ,form ,(car sparameter) ,optimized-form))
263        `(accessor-slot-boundp ,@(cdr form)))))
264
265(defmacro optimized-slot-boundp (form parameter-name optimized-form
266                                 &environment env)
267  (if (parameter-modified-p parameter-name env)
268      `(accessor-slot-boundp ,@(cdr form))
269      optimized-form))
270
271;;; The SLOTS argument is an alist, the CAR of each entry is the name
272;;; of a required parameter to the function. The alist is in order, so
273;;; the position of an entry in the alist corresponds to the
274;;; argument's position in the lambda list.
275(defun optimize-instance-access (slots read/write sparameter slot-name
276                                 new-value &optional safep)
277  (let ((class (if (consp sparameter) (cdr sparameter) *the-class-t*))
278        (parameter (if (consp sparameter) (car sparameter) sparameter)))
279    (if (and (eq **boot-state** 'complete)
280             (classp class)
281             (memq *the-class-structure-object* (class-precedence-list class)))
282        (let ((slotd (find-slot-definition class slot-name)))
283          (ecase read/write
284            (:read
285             `(,(slot-definition-defstruct-accessor-symbol slotd) ,parameter))
286            (:write
287             `(setf (,(slot-definition-defstruct-accessor-symbol slotd)
288                     ,parameter)
289                    ,new-value))
290            (:boundp
291             t)))
292        (let* ((parameter-entry (assq parameter slots))
293               (slot-entry      (assq slot-name (cdr parameter-entry)))
294               (position (posq parameter-entry slots))
295               (pv-offset-form (list 'pv-offset ''.PV-OFFSET.)))
296          (unless parameter-entry
297            (bug "slot optimization bewilderment: O-I-A"))
298          (unless slot-entry
299            (setq slot-entry (list slot-name))
300            (push slot-entry (cdr parameter-entry)))
301          (push pv-offset-form (cdr slot-entry))
302          (ecase read/write
303            (:read
304             `(instance-read ,pv-offset-form ,parameter ,position
305                             ',slot-name ',class))
306            (:write
307             `(let ((.new-value. ,new-value))
308                (instance-write ,pv-offset-form ,parameter ,position
309                                ',slot-name ',class .new-value. ,safep)))
310            (:boundp
311             `(instance-boundp ,pv-offset-form ,parameter ,position
312                               ',slot-name ',class)))))))
313
314(define-walker-template pv-offset) ; These forms get munged by mutate slots.
315(defmacro pv-offset (arg) arg)
316(define-walker-template instance-accessor-parameter)
317(defmacro instance-accessor-parameter (x) x)
318
319;;; It is safe for these two functions to be wrong. They just try to
320;;; guess what the most likely case will be.
321(defun generate-fast-class-slot-access-p (class-form slot-name-form)
322  (let ((class (and (constantp class-form) (constant-form-value class-form)))
323        (slot-name (and (constantp slot-name-form)
324                        (constant-form-value slot-name-form))))
325    (and (eq **boot-state** 'complete)
326         (standard-class-p class)
327         (not (eq class *the-class-t*)) ; shouldn't happen, though.
328         (let ((slotd (find-slot-definition class slot-name)))
329           (and slotd (eq :class (slot-definition-allocation slotd)))))))
330
331(defun constant-value-or-nil (form)
332  (and (constantp form) (constant-form-value form)))
333
334(defun slot-access-strategy (class slot-name type &optional conservative)
335  ;; CONSERVATIVE means we should assume custom access pattern even if
336  ;; there are no custom accessors defined if the metaclass is non-standard.
337  ;;
338  ;; This is needed because DEFCLASS generates accessor methods before possible
339  ;; SLOT-VALUE-USING-CLASS methods are defined, which causes them to take
340  ;; the slow path unless we make the conservative assumption here.
341  (if (eq **boot-state** 'complete)
342      (let (slotd)
343        (cond ((or
344                ;; Conditions, structures, and classes for which FIND-CLASS
345                ;; doesn't return them yet.
346                ;; FIXME: surely we can get faster accesses for structures?
347                (not (standard-class-p class))
348                ;; Should not happen... (FIXME: assert instead?)
349                (eq class *the-class-t*)
350                (not (class-finalized-p class))
351                ;; Strangeness...
352                (not (setf slotd (find-slot-definition class slot-name))))
353               :accessor)
354              ((and (slot-accessor-std-p slotd type)
355                    (or (not conservative) (eq *the-class-standard-class* (class-of class))))
356               ;; The best case.
357               :standard)
358              (t
359               :custom)))
360      :standard))
361
362;;;; SLOT-VALUE
363
364(defmacro instance-read (pv-offset parameter position slot-name class)
365  (ecase (slot-access-strategy (constant-value-or-nil class)
366                               (constant-value-or-nil slot-name)
367                               'reader)
368    (:standard
369     `(instance-read-standard
370       .pv. ,(slot-vector-symbol position)
371       ,pv-offset (accessor-slot-value ,parameter ,slot-name)
372       ,(if (generate-fast-class-slot-access-p class slot-name)
373            :class :instance)))
374    (:custom
375     `(instance-read-custom .pv. ,pv-offset ,parameter))
376    (:accessor
377     `(accessor-slot-value ,parameter ,slot-name))))
378
379(defmacro instance-read-standard (pv slots pv-offset default &optional kind)
380  (unless (member kind '(nil :instance :class))
381    (error "illegal kind argument to ~S: ~S" 'instance-read-standard kind))
382  (let* ((index (gensym))
383         (value index))
384    `(locally (declare #.*optimize-speed*)
385       (let ((,index (svref ,pv ,pv-offset))
386             (,slots (truly-the simple-vector ,slots)))
387         (setq ,value (typecase ,index
388                        ;; FIXME: the line marked by KLUDGE below (and
389                        ;; the analogous spot in
390                        ;; INSTANCE-WRITE-STANDARD) is there purely to
391                        ;; suppress a type mismatch warning that
392                        ;; propagates through to user code.
393                        ;; Presumably SLOTS at this point can never
394                        ;; actually be NIL, but the compiler seems to
395                        ;; think it could, so we put this here to shut
396                        ;; it up.  (see also mail Rudi Schlatte
397                        ;; sbcl-devel 2003-09-21) -- CSR, 2003-11-30
398                        ,@(when (or (null kind) (eq kind :instance))
399                                `((fixnum
400                                   (clos-slots-ref ,slots ,index))))
401                        ,@(when (or (null kind) (eq kind :class))
402                                `((cons (cdr ,index))))
403                        (t
404                         +slot-unbound+)))
405         (if (eq ,value +slot-unbound+)
406             ,default
407             ,value)))))
408
409(defmacro instance-read-custom (pv pv-offset parameter)
410  `(locally (declare #.*optimize-speed*)
411     (funcall (slot-info-reader (svref ,pv (1+ ,pv-offset))) ,parameter)))
412
413;;;; (SETF SLOT-VALUE)
414
415(defmacro instance-write (pv-offset parameter position slot-name class new-value
416                          &optional check-type-p)
417  (ecase (slot-access-strategy (constant-value-or-nil class)
418                               (constant-value-or-nil slot-name)
419                               'writer)
420    (:standard
421     `(instance-write-standard
422       .pv. ,(slot-vector-symbol position)
423       ,pv-offset ,new-value
424       ;; KLUDGE: .GOOD-NEW-VALUE. is type-checked by the time this form
425       ;; is executed (if it is executed).
426       (accessor-set-slot-value ,parameter ,slot-name .good-new-value.)
427       ,(if (generate-fast-class-slot-access-p class slot-name)
428            :class :instance)
429       ,check-type-p))
430    (:custom
431     `(instance-write-custom .pv. ,pv-offset ,parameter ,new-value))
432    (:accessor
433     (if check-type-p
434         ;; FIXME: We don't want this here. If it's _possible_ the fast path
435         ;; is applicable, we want to use it as well.
436         `(safe-set-slot-value ,parameter ,slot-name ,new-value)
437         `(accessor-set-slot-value ,parameter ,slot-name ,new-value)))))
438
439(defmacro instance-write-standard (pv slots pv-offset new-value default
440                                   &optional kind safep)
441  (unless (member kind '(nil :instance :class))
442    (error "illegal kind argument to ~S: ~S" 'instance-write-standard kind))
443  (let* ((index (gensym))
444         (new-value-form
445          (if safep
446              `(let ((.typecheckfun. (slot-info-typecheck (svref ,pv (1+ ,pv-offset)))))
447                 (declare (type (or function null) .typecheckfun.))
448                 (if .typecheckfun.
449                     (funcall .typecheckfun. ,new-value)
450                     ,new-value))
451              new-value)))
452    `(locally (declare #.*optimize-speed*)
453       (let ((.good-new-value. ,new-value-form)
454             (,index (svref ,pv ,pv-offset)))
455         (typecase ,index
456           ,@(when (or (null kind) (eq kind :instance))
457                   `((fixnum (and ,slots
458                                  (setf (clos-slots-ref ,slots ,index)
459                                        .good-new-value.)))))
460           ,@(when (or (null kind) (eq kind :class))
461                   `((cons (setf (cdr ,index) .good-new-value.))))
462           (t ,default))))))
463
464(defmacro instance-write-custom (pv pv-offset parameter new-value)
465  `(locally (declare #.*optimize-speed*)
466     (funcall (slot-info-writer (svref ,pv (1+ ,pv-offset))) ,new-value ,parameter)))
467
468;;;; SLOT-BOUNDP
469
470(defmacro instance-boundp (pv-offset parameter position slot-name class)
471  (ecase (slot-access-strategy (constant-value-or-nil class)
472                               (constant-value-or-nil slot-name)
473                               'boundp)
474    (:standard
475     `(instance-boundp-standard
476       .pv. ,(slot-vector-symbol position)
477       ,pv-offset (accessor-slot-boundp ,parameter ,slot-name)
478       ,(if (generate-fast-class-slot-access-p class slot-name)
479            :class :instance)))
480    (:custom
481     `(instance-boundp-custom .pv. ,pv-offset ,parameter))
482    (:accessor
483     `(accessor-slot-boundp ,parameter ,slot-name))))
484
485(defmacro instance-boundp-standard (pv slots pv-offset default
486                                    &optional kind)
487  (unless (member kind '(nil :instance :class))
488    (error "illegal kind argument to ~S: ~S" 'instance-boundp-standard kind))
489  (let* ((index (gensym)))
490    `(locally (declare #.*optimize-speed*)
491       (let ((,index (svref ,pv ,pv-offset)))
492         (typecase ,index
493           ,@(when (or (null kind) (eq kind :instance))
494                   `((fixnum (not (and ,slots
495                                       (eq (clos-slots-ref ,slots ,index)
496                                           +slot-unbound+))))))
497           ,@(when (or (null kind) (eq kind :class))
498                   `((cons (not (eq (cdr ,index) +slot-unbound+)))))
499           (t ,default))))))
500
501(defmacro instance-boundp-custom (pv pv-offset parameter)
502  `(locally (declare #.*optimize-speed*)
503     (funcall (slot-info-boundp (svref ,pv (1+ ,pv-offset))) ,parameter)))
504
505;;; This magic function has quite a job to do indeed.
506;;;
507;;; The careful reader will recall that <slots> contains all of the
508;;; optimized slot access forms produced by OPTIMIZE-INSTANCE-ACCESS.
509;;; Each of these is a call to either INSTANCE-READ or INSTANCE-WRITE.
510;;;
511;;; At the time these calls were produced, the first argument was
512;;; specified as the symbol .PV-OFFSET.; what we have to do now is
513;;; convert those pv-offset arguments into the actual number that is
514;;; the correct offset into the pv.
515;;;
516;;; But first, oh but first, we sort <slots> a bit so that for each
517;;; argument we have the slots in an order defined by
518;;; SYMBOL-OR-CONS-LESSP. This canonicalizes the PV-TABLEs a bit and
519;;; will hopefully lead to having fewer PVs floating around. Even if
520;;; the gain is only modest, it costs nothing.
521(defun slot-name-lists-from-slots (slots)
522  (mapcar (lambda (parameter-entry)
523            (when (cdr parameter-entry)
524              (mapcar #'car (cdr parameter-entry))))
525          (mutate-slots slots)))
526
527(defun mutate-slots (slots)
528  (let ((sorted-slots (sort-slots slots))
529        (pv-offset -1))
530    (dolist (parameter-entry sorted-slots)
531      (dolist (slot-entry (cdr parameter-entry))
532        (incf pv-offset)
533        (dolist (form (cdr slot-entry))
534          (setf (cadr form) pv-offset))
535        ;; Count one more for the slot we use for SLOT-INFO.
536        (incf pv-offset)))
537    sorted-slots))
538
539(defun symbol-or-cons-lessp (a b)
540  (etypecase a
541    (symbol (etypecase b
542              (symbol (< (symbol-hash a) (symbol-hash b)))
543              (cons t)))
544    (cons   (etypecase b
545              (symbol nil)
546              (cons (if (eq (car a) (car b))
547                        (symbol-or-cons-lessp (cdr a) (cdr b))
548                        (symbol-or-cons-lessp (car a) (car b))))))))
549
550(defun sort-slots (slots)
551  (mapcar (lambda (parameter-entry)
552            (destructuring-bind (name . entries) parameter-entry
553              (cons name (stable-sort entries #'symbol-or-cons-lessp
554                                      :key #'car))))
555          slots))
556
557
558;;;; This needs to work in terms of metatypes and also needs to work
559;;;; for automatically generated reader and writer functions.
560;;;; Automatically generated reader and writer functions use this
561;;;; stuff too.
562
563(defmacro pv-binding ((required-parameters slot-name-lists pv-table-form)
564                      &body body)
565  (let (slot-vars pv-parameters)
566    (loop for slots in slot-name-lists
567          for required-parameter in required-parameters
568          for i from 0
569          do (when slots
570               (push required-parameter pv-parameters)
571               (push (slot-vector-symbol i) slot-vars)))
572    `(pv-binding1 (,pv-table-form
573                   ,(nreverse pv-parameters) ,(nreverse slot-vars))
574       ,@body)))
575
576(defmacro pv-binding1 ((pv-table-form pv-parameters slot-vars)
577                       &body body)
578  `(pv-env (,pv-table-form ,pv-parameters)
579     (let (,@(mapcar (lambda (slot-var p) `(,slot-var (get-slots-or-nil ,p)))
580                     slot-vars pv-parameters))
581       (declare (ignorable ,@(mapcar #'identity slot-vars)))
582       ,@body)))
583
584;;; This will only be visible in PV-ENV when the default MAKE-METHOD-LAMBDA is
585;;; overridden.
586(define-symbol-macro pv-env-environment overridden)
587
588(defmacro pv-env (&environment env
589                  (pv-table-form pv-parameters)
590                  &rest forms)
591  ;; Decide which expansion to use based on the state of the PV-ENV-ENVIRONMENT
592  ;; symbol-macrolet.
593  (if (eq (macroexpand 'pv-env-environment env) 'default)
594      `(locally (declare (simple-vector .pv.))
595         ,@forms)
596      `(let* ((.pv-table. ,pv-table-form)
597              (.pv. (pv-table-lookup-pv-args .pv-table. ,@pv-parameters)))
598        (declare ,(make-pv-type-declaration '.pv.))
599        ,@forms)))
600
601(defun split-declarations (body args req-args cnm-p parameters-setqd)
602  (let ((inner-decls nil)
603        (outer-decls nil)
604        decl)
605    (loop
606      (when (null body)
607        (return nil))
608      (setq decl (car body))
609      (unless (and (consp decl) (eq (car decl) 'declare))
610        (return nil))
611      (dolist (form (cdr decl))
612        (when (consp form)
613          (let* ((name (car form)))
614            (cond ((eq '%class name)
615                   (push `(declare ,form) inner-decls))
616                  ((or (member name '(ignore ignorable special dynamic-extent type))
617                       (info :type :kind name))
618                   (let* ((inners nil)
619                          (outers nil)
620                          (tail (cdr form))
621                          (head (if (eq 'type name)
622                                    (list name (pop tail))
623                                    (list name))))
624                     (dolist (var tail)
625                       (if (member var args :test #'eq)
626                           ;; Quietly remove IGNORE declarations on
627                           ;; args when a next-method is involved, to
628                           ;; prevent compiler warnings about ignored
629                           ;; args being read.
630                           (unless (and (eq 'ignore name)
631                                        (member var req-args :test #'eq)
632                                        (or cnm-p (member var parameters-setqd)))
633                             (push var outers))
634                           (push var inners)))
635                     (when outers
636                       (push `(declare (,@head ,@outers)) outer-decls))
637                     (when inners
638                       (push `(declare (,@head ,@inners)) inner-decls))))
639                  (t
640                   ;; All other declarations are not variable declarations,
641                   ;; so they become outer declarations.
642                   (push `(declare ,form) outer-decls))))))
643      (setq body (cdr body)))
644    (values outer-decls inner-decls body)))
645
646;;; Convert a lambda expression containing a SB-PCL::%METHOD-NAME
647;;; declaration (which is a naming style internal to PCL) into an
648;;; SB-INT:NAMED-LAMBDA expression (which is a naming style used
649;;; throughout SBCL, understood by the main compiler); or if there's
650;;; no SB-PCL::%METHOD-NAME declaration, then just return the original
651;;; lambda expression.
652(defun name-method-lambda (method-lambda)
653  (let ((method-name *method-name*))
654    (if method-name
655        `(named-lambda (slow-method ,@method-name) ,@(rest method-lambda))
656        method-lambda)))
657
658(defun make-method-initargs-form-internal (method-lambda initargs env)
659  (declare (ignore env))
660  (let (method-lambda-args
661        lmf ; becomes body of function
662        lmf-params)
663    (if (not (and (= 3 (length method-lambda))
664                  (= 2 (length (setq method-lambda-args (cadr method-lambda))))
665                  (consp (setq lmf (third method-lambda)))
666                  (eq 'simple-lexical-method-functions (car lmf))
667                  (eq (car method-lambda-args)
668                      (cadr (setq lmf-params (cadr lmf))))
669                  (eq (cadr method-lambda-args)
670                      (caddr lmf-params))))
671        `(list* :function ,(name-method-lambda method-lambda)
672                ',initargs)
673        (let* ((lambda-list (car lmf-params))
674               (nreq 0)
675               (restp nil)
676               (args nil))
677          (dolist (arg lambda-list)
678            (when (member arg '(&optional &rest &key))
679              (setq restp t)
680              (return nil))
681            (when (eq arg '&aux)
682              (return nil))
683            (incf nreq)
684            (push arg args))
685          (setq args (nreverse args))
686          (setf (getf (getf initargs 'plist) :arg-info) (cons nreq restp))
687          (make-method-initargs-form-internal1
688           initargs (cddr lmf) args lmf-params restp)))))
689
690(defun lambda-list-parameter-names (lambda-list)
691  ;; Given a valid lambda list, extract the parameter names.
692  (loop for x in lambda-list
693        with res = nil
694        do (unless (member x lambda-list-keywords :test #'eq)
695             (if (consp x)
696                 (let ((name (car x)))
697                   (if (consp name)
698                       ;; ... ((:BAR FOO) 1)
699                       (push (second name) res)
700                       ;; ... (FOO 1)
701                       (push name res))
702                   ;; ... (... 1 FOO-P)
703                   (let ((name-p (cddr x)))
704                     (when name-p
705                       (push (car name-p) res))))
706                 ;; ... FOO
707                 (push x res)))
708        finally (return res)))
709
710(defun make-method-initargs-form-internal1
711    (initargs body req-args lmf-params restp)
712  (let* (;; The lambda-list of the method, minus specifiers
713         (lambda-list (car lmf-params))
714         ;; Names of the parameters that will be in the outermost lambda-list
715         ;; (and whose bound declarations thus need to be in OUTER-DECLS).
716         (outer-parameters req-args)
717         ;; The lambda-list used by BIND-ARGS
718         (bind-list lambda-list)
719         (parameters-setqd (getf (cdr lmf-params) :parameters-setqd))
720         (auxp (member '&aux bind-list))
721         (call-next-method-p (getf (cdr lmf-params) :call-next-method-p)))
722    ;; Try to use the normal function call machinery instead of BIND-ARGS
723    ;; binding the arguments, unless:
724    (unless (or ;; If all arguments are required, BIND-ARGS will be a no-op
725                ;; in any case.
726                (and (not restp) (not auxp))
727                ;; CALL-NEXT-METHOD wants to use BIND-ARGS, and needs a
728                ;; list of all non-required arguments.
729                call-next-method-p)
730      (setf ;; We don't want a binding for .REST-ARG.
731            restp nil
732            ;; Get all the parameters for declaration parsing
733            outer-parameters (lambda-list-parameter-names lambda-list)
734            ;; Ensure that BIND-ARGS won't do anything (since
735            ;; BIND-LIST won't contain any non-required parameters,
736            ;; and REQ-ARGS will be of an equal length). We still want
737            ;; to pass BIND-LIST to FAST-LEXICAL-METHOD-FUNCTIONS so
738            ;; that BIND-FAST-LEXICAL-METHOD-FUNCTIONS can take care
739            ;; of rebinding SETQd required arguments around the method
740            ;; body.
741            bind-list req-args))
742    (multiple-value-bind (outer-decls inner-decls body-sans-decls)
743        (split-declarations
744         body outer-parameters req-args call-next-method-p parameters-setqd)
745      (let* ((rest-arg (when restp
746                         '.rest-arg.))
747             (fmf-lambda-list (if rest-arg
748                                  (append req-args (list '&rest rest-arg))
749                                  (if call-next-method-p
750                                      req-args
751                                      lambda-list))))
752        `(list*
753          :function
754          (let* ((fmf (,(if *method-name* 'named-lambda 'lambda)
755                        ,@(when *method-name*
756                                ;; function name
757                                (list `(fast-method ,@*method-name*)))
758                        ;; The lambda-list of the FMF
759                        (.pv. .next-method-call. ,@fmf-lambda-list)
760                        ;; body of the function
761                        (declare (ignorable .pv. .next-method-call.)
762                                 (disable-package-locks pv-env-environment))
763                        ,@outer-decls
764                        (symbol-macrolet ((pv-env-environment default))
765                          (fast-lexical-method-functions
766                              (,bind-list .next-method-call. ,req-args ,rest-arg
767                                ,@(cdddr lmf-params))
768                            ,@inner-decls
769                            ,@body-sans-decls))))
770                 (mf (%make-method-function fmf nil)))
771            (set-funcallable-instance-function
772             mf (method-function-from-fast-function fmf ',(getf initargs 'plist)))
773            mf)
774          ',initargs)))))
775
776;;; Use arrays and hash tables and the fngen stuff to make this much
777;;; better. It doesn't really matter, though, because a function
778;;; returned by this will get called only when the user explicitly
779;;; funcalls a result of method-function. BUT, this is needed to make
780;;; early methods work.
781(defun method-function-from-fast-function (fmf plist)
782  (declare (type function fmf))
783  (let* ((method-function nil)
784         (snl (getf plist :slot-name-lists))
785         (pv-table (when snl
786                     (intern-pv-table :slot-name-lists snl))))
787    (setq method-function
788          (lambda (method-args next-methods)
789            (let* ((pv (when pv-table
790                         (get-pv method-args pv-table)))
791                   (nm (car next-methods))
792                   (nms (cdr next-methods))
793                   (nmc (when nm
794                          (make-method-call
795                           :function (if (std-instance-p nm)
796                                         (method-function nm)
797                                         nm)
798                           :call-method-args (list nms)))))
799              (apply fmf pv nmc method-args))))
800    ;; FIXME: this looks dangerous.
801    (let* ((fname (%fun-name fmf)))
802      (when (and fname (eq (car fname) 'fast-method))
803        (set-fun-name method-function (cons 'slow-method (cdr fname)))))
804    method-function))
805
806;;; this is similar to the above, only not quite.  Only called when
807;;; the MOP is heavily involved.  Not quite parallel to
808;;; METHOD-FUNCTION-FROM-FAST-METHOD-FUNCTION, because we can close
809;;; over the actual PV-CELL in this case.
810(defun method-function-from-fast-method-call (fmc)
811  (let* ((fmf (fast-method-call-function fmc))
812         (pv (fast-method-call-pv fmc)))
813    (lambda (method-args next-methods)
814      (let* ((nm (car next-methods))
815             (nms (cdr next-methods))
816             (nmc (when nm
817                    (make-method-call
818                     :function (if (std-instance-p nm)
819                                   (method-function nm)
820                                   nm)
821                     :call-method-args (list nms)))))
822        (apply fmf pv nmc method-args)))))
823
824(defun get-pv (method-args pv-table)
825  (let ((pv-wrappers (pv-wrappers-from-all-args pv-table method-args)))
826    (when pv-wrappers
827      (pv-table-lookup pv-table pv-wrappers))))
828
829(defun pv-table-lookup-pv-args (pv-table &rest pv-parameters)
830  (pv-table-lookup pv-table (pv-wrappers-from-pv-args pv-parameters)))
831
832(defun pv-wrappers-from-pv-args (&rest args)
833  (mapcar #'valid-wrapper-of args))
834
835(defun pv-wrappers-from-all-args (pv-table args)
836  (loop for snl in (pv-table-slot-name-lists pv-table)
837        and arg in args
838        when snl
839        collect (valid-wrapper-of arg)))
840
841;;; Return the subset of WRAPPERS which is used in the cache
842;;; of PV-TABLE.
843(defun pv-wrappers-from-all-wrappers (pv-table wrappers)
844  (loop for snl in (pv-table-slot-name-lists pv-table)
845        and w in wrappers
846        when snl
847        collect w))
848