1;;;; This software is part of the SBCL system. See the README file for
2;;;; more information.
3
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
8;;;; information.
9
10;;;; copyright information from original PCL sources:
11;;;;
12;;;; Copyright (c) 1985, 1986, 1987, 1988, 1989, 1990 Xerox Corporation.
13;;;; All rights reserved.
14;;;;
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
18;;;; control laws.
19;;;;
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
22;;;; specification.
23
24(in-package "SB-PCL")
25
26#|
27
28The CommonLoops evaluator is meta-circular.
29
30Most of the code in PCL is methods on generic functions, including
31most of the code that actually implements generic functions and method
32lookup.
33
34So, we have a classic bootstrapping problem. The solution to this is
35to first get a cheap implementation of generic functions running,
36these are called early generic functions. These early generic
37functions and the corresponding early methods and early method lookup
38are used to get enough of the system running that it is possible to
39create real generic functions and methods and implement real method
40lookup. At that point (done in the file FIXUP) the function
41!FIX-EARLY-GENERIC-FUNCTIONS is called to convert all the early generic
42functions to real generic functions.
43
44The cheap generic functions are built using the same
45FUNCALLABLE-INSTANCE objects that real generic functions are made out of.
46This means that as PCL is being bootstrapped, the cheap generic
47function objects which are being created are the same objects which
48will later be real generic functions. This is good because:
49  - we don't cons garbage structure, and
50  - we can keep pointers to the cheap generic function objects
51    during booting because those pointers will still point to
52    the right object after the generic functions are all fixed up.
53
54This file defines the DEFMETHOD macro and the mechanism used to expand
55it. This includes the mechanism for processing the body of a method.
56DEFMETHOD basically expands into a call to LOAD-DEFMETHOD, which
57basically calls ADD-METHOD to add the method to the generic function.
58These expansions can be loaded either during bootstrapping or when PCL
59is fully up and running.
60
61An important effect of this arrangement is it means we can compile
62files with DEFMETHOD forms in them in a completely running PCL, but
63then load those files back in during bootstrapping. This makes
64development easier. It also means there is only one set of code for
65processing DEFMETHOD. Bootstrapping works by being sure to have
66LOAD-METHOD be careful to call only primitives which work during
67bootstrapping.
68
69|#
70
71(declaim (notinline make-a-method add-named-method
72                    ensure-generic-function-using-class
73                    add-method remove-method))
74
75(defvar *!early-functions*
76  '((make-a-method !early-make-a-method real-make-a-method)
77    (add-named-method !early-add-named-method real-add-named-method)))
78
79;;; For each of the early functions, arrange to have it point to its
80;;; early definition. Do this in a way that makes sure that if we
81;;; redefine one of the early definitions the redefinition will take
82;;; effect. This makes development easier.
83(loop for (name early-name) in *!early-functions*
84   do (let ((early-name early-name))
85        (setf (gdefinition name)
86              (set-fun-name
87               (lambda (&rest args)
88                 (apply (fdefinition early-name) args))
89               name))))
90
91;;; *!GENERIC-FUNCTION-FIXUPS* is used by !FIX-EARLY-GENERIC-FUNCTIONS
92;;; to convert the few functions in the bootstrap which are supposed
93;;; to be generic functions but can't be early on.
94;;;
95;;; each entry is a list of the form
96;;;
97;;;   (GENERIC-FUNCTION-NAME METHOD-COMBINATION-NAME METHODS)
98;;;
99;;; where methods is a list of lists of the form
100;;;
101;;;   (LAMBDA-LIST SPECIALIZERS QUALIFIERS METHOD-BODY-FUNCTION-NAME)
102;;;
103;;;,where SPECIALIZERS is a list of class names.
104(defvar *!generic-function-fixups*
105  '((add-method
106     standard
107     ((generic-function method)
108      (standard-generic-function method)
109      ()
110      real-add-method))
111
112    (remove-method
113     standard
114     ((generic-function method)
115      (standard-generic-function method)
116      ()
117      real-remove-method))
118
119    (get-method
120     standard
121     ((generic-function qualifiers specializers &optional (errorp t))
122      (standard-generic-function t t)
123      ()
124      real-get-method))
125
126    (ensure-generic-function-using-class
127     standard
128     ((generic-function fun-name
129                        &key generic-function-class environment
130                        &allow-other-keys)
131      (generic-function t)
132      ()
133      real-ensure-gf-using-class--generic-function)
134     ((generic-function fun-name
135                        &key generic-function-class environment
136                        &allow-other-keys)
137      (null t)
138      ()
139      real-ensure-gf-using-class--null))
140
141    (make-method-lambda
142     standard
143     ((proto-generic-function proto-method lambda-expression environment)
144      (standard-generic-function standard-method t t)
145      ()
146      real-make-method-lambda))
147
148    (make-method-lambda-using-specializers
149     standard
150     ((proto-generic-function proto-method qualifiers specializers
151                              lambda-expression environment)
152      (standard-generic-function standard-method t t t t)
153      ()
154      real-make-method-lambda-using-specializers))
155
156    (make-method-specializers-form
157     standard
158     ((proto-generic-function proto-method specializer-names environment)
159      (standard-generic-function standard-method t t)
160      ()
161      real-make-method-specializers-form))
162
163    (make-specializer-form-using-class
164     or
165     ((proto-generic-function proto-method specializer-name environment)
166      (standard-generic-function standard-method t t)
167      (or)
168      real-make-specializer-form-using-class/t)
169     ((proto-generic-function proto-method specializer-name environment)
170      (standard-generic-function standard-method specializer t)
171      (or)
172      real-make-specializer-form-using-class/specializer)
173     ((proto-generic-function proto-method specializer-name environment)
174      (standard-generic-function standard-method symbol t)
175      (or)
176      real-make-specializer-form-using-class/symbol)
177     ((proto-generic-function proto-method specializer-name environment)
178      (standard-generic-function standard-method cons t)
179      (or)
180      real-make-specializer-form-using-class/cons))
181
182    (parse-specializer-using-class
183     standard
184     ((generic-function specializer)
185      (standard-generic-function t)
186      ()
187      real-parse-specializer-using-class))
188
189    (unparse-specializer-using-class
190     standard
191     ((generic-function specializer)
192      (standard-generic-function t)
193      ()
194      real-unparse-specializer-using-class))
195
196    (make-method-initargs-form
197     standard
198     ((proto-generic-function proto-method
199                              lambda-expression
200                              lambda-list environment)
201      (standard-generic-function standard-method t t t)
202      ()
203      real-make-method-initargs-form))
204
205    (compute-effective-method
206     standard
207     ((generic-function combin applicable-methods)
208      (generic-function standard-method-combination t)
209      ()
210      standard-compute-effective-method)
211     ((generic-function combin applicable-methods)
212      (generic-function short-method-combination t)
213      ()
214      short-compute-effective-method))))
215
216(defmacro defgeneric (fun-name lambda-list &body options)
217  (declare (type list lambda-list))
218  (unless (legal-fun-name-p fun-name)
219    (error 'simple-program-error
220           :format-control "illegal generic function name ~S"
221           :format-arguments (list fun-name)))
222  (check-gf-lambda-list lambda-list)
223  (let ((initargs ())
224        (methods ()))
225    (flet ((duplicate-option (name)
226             (error 'simple-program-error
227                    :format-control "The option ~S appears more than once."
228                    :format-arguments (list name)))
229           (expand-method-definition (qab) ; QAB = qualifiers, arglist, body
230             (let* ((arglist-pos (position-if #'listp qab))
231                    (arglist (elt qab arglist-pos))
232                    (qualifiers (subseq qab 0 arglist-pos))
233                    (body (nthcdr (1+ arglist-pos) qab)))
234               `(push (defmethod ,fun-name ,@qualifiers ,arglist ,@body)
235                      (generic-function-initial-methods (fdefinition ',fun-name))))))
236      (macrolet ((initarg (key) `(getf initargs ,key)))
237        (dolist (option options)
238          (let ((car-option (car option)))
239            (case car-option
240              (declare
241               (dolist (spec (cdr option))
242                 (unless (consp spec)
243                   (error 'simple-program-error
244                          :format-control "~@<Invalid declaration specifier in ~
245                                           DEFGENERIC: ~S~:@>"
246                          :format-arguments (list spec)))
247                 (when (member (first spec)
248                               ;; FIXME: this list is slightly weird.
249                               ;; ANSI (on the DEFGENERIC page) in one
250                               ;; place allows only OPTIMIZE; in
251                               ;; another place gives this list of
252                               ;; disallowed declaration specifiers.
253                               ;; This seems to be the only place where
254                               ;; the FUNCTION declaration is
255                               ;; mentioned; TYPE seems to be missing.
256                               ;; Very strange.  -- CSR, 2002-10-21
257                               '(declaration ftype function
258                                 inline notinline special))
259                   (error 'simple-program-error
260                          :format-control "The declaration specifier ~S ~
261                                         is not allowed inside DEFGENERIC."
262                          :format-arguments (list spec)))
263                 (if (or (eq 'optimize (first spec))
264                         (info :declaration :recognized (first spec)))
265                     (push spec (initarg :declarations))
266                     (warn "Ignoring unrecognized declaration in DEFGENERIC: ~S"
267                           spec))))
268              (:method-combination
269               (when (initarg car-option)
270                 (duplicate-option car-option))
271               (unless (symbolp (cadr option))
272                 (error 'simple-program-error
273                        :format-control "METHOD-COMBINATION name not a ~
274                                         symbol: ~S"
275                        :format-arguments (list (cadr option))))
276               (setf (initarg car-option)
277                     `',(cdr option)))
278              (:argument-precedence-order
279               (let* ((required (nth-value 1 (parse-lambda-list lambda-list)))
280                      (supplied (cdr option)))
281                 (unless (= (length required) (length supplied))
282                   (error 'simple-program-error
283                          :format-control "argument count discrepancy in ~
284                                           :ARGUMENT-PRECEDENCE-ORDER clause."
285                          :format-arguments nil))
286                 (when (set-difference required supplied)
287                   (error 'simple-program-error
288                          :format-control "unequal sets for ~
289                                           :ARGUMENT-PRECEDENCE-ORDER clause: ~
290                                           ~S and ~S"
291                          :format-arguments (list required supplied)))
292                 (setf (initarg car-option)
293                       `',(cdr option))))
294              ((:documentation :generic-function-class :method-class)
295               (unless (proper-list-of-length-p option 2)
296                 (error "bad list length for ~S" option))
297               (if (initarg car-option)
298                   (duplicate-option car-option)
299                   (setf (initarg car-option) `',(cadr option))))
300              (:method
301               (push (cdr option) methods))
302              (t
303               ;; ANSI requires that unsupported things must get a
304               ;; PROGRAM-ERROR.
305               (error 'simple-program-error
306                      :format-control "unsupported option ~S"
307                      :format-arguments (list option))))))
308
309        (when (initarg :declarations)
310          (setf (initarg :declarations)
311                `',(initarg :declarations))))
312      `(progn
313         (eval-when (:compile-toplevel :load-toplevel :execute)
314           (compile-or-load-defgeneric ',fun-name))
315         (load-defgeneric ',fun-name ',lambda-list
316                          (sb-c:source-location) ,@initargs)
317         ,@(mapcar #'expand-method-definition methods)
318         (fdefinition ',fun-name)))))
319
320(defun compile-or-load-defgeneric (fun-name)
321  (proclaim-as-fun-name fun-name)
322  (when (typep fun-name '(cons (eql setf)))
323    (sb-c::warn-if-setf-macro fun-name))
324  (note-name-defined fun-name :function)
325  (unless (eq (info :function :where-from fun-name) :declared)
326    ;; Hmm. This is similar to BECOME-DEFINED-FUN-NAME
327    ;; except that it doesn't clear an :ASSUMED-TYPE. Should it?
328    (setf (info :function :where-from fun-name) :defined)
329    (setf (info :function :type fun-name)
330          (specifier-type 'function))))
331
332(defun load-defgeneric (fun-name lambda-list source-location &rest initargs)
333  (when (fboundp fun-name)
334    (warn 'sb-kernel:redefinition-with-defgeneric
335          :name fun-name
336          :new-location source-location)
337    (let ((fun (fdefinition fun-name)))
338      (when (generic-function-p fun)
339        (loop for method in (generic-function-initial-methods fun)
340              do (remove-method fun method))
341        (setf (generic-function-initial-methods fun) '()))))
342  (apply #'ensure-generic-function
343         fun-name
344         :lambda-list lambda-list
345         :definition-source source-location
346         initargs))
347
348(define-condition generic-function-lambda-list-error
349    (reference-condition simple-program-error)
350  ()
351  (:default-initargs :references (list '(:ansi-cl :section (3 4 2)))))
352
353(defun check-gf-lambda-list (lambda-list)
354  (flet ((verify-each-atom-or-singleton (kind args)
355           ;; PARSE-LAMBDA-LIST validates the skeleton,
356           ;; so just check for incorrect use of defaults.
357           ;; This works for both &OPTIONAL and &KEY.
358           (dolist (arg args)
359             (or (not (listp arg))
360                 (null (cdr arg))
361                 (error 'generic-function-lambda-list-error
362                    :format-control
363                    "~@<invalid ~A argument specifier ~S ~_in the ~
364generic function lambda list ~S~:>"
365                    :format-arguments (list kind arg lambda-list))))))
366    (multiple-value-bind (llks required optional rest keys)
367        (parse-lambda-list
368         lambda-list
369         :accept (lambda-list-keyword-mask
370                    '(&optional &rest &key &allow-other-keys))
371         :condition-class 'generic-function-lambda-list-error
372         :context "a generic function lambda list")
373      (declare (ignore llks required rest))
374      ;; no defaults or supplied-p vars allowed for &OPTIONAL or &KEY
375      (verify-each-atom-or-singleton '&optional optional)
376      (verify-each-atom-or-singleton '&key keys))))
377
378(defun check-method-lambda (method-lambda context)
379  (unless (typep method-lambda '(cons (eql lambda)))
380    (error "~@<The METHOD-LAMBDA argument to ~
381            ~/sb-impl:print-symbol-with-prefix/, ~S, is not a lambda ~
382            form.~@:>"
383           context method-lambda))
384  method-lambda)
385
386(eval-when (:compile-toplevel :load-toplevel :execute)
387  (fmakunbound 'defmethod))
388;;; As per CLHS -
389;;; "defmethod is not required to perform any compile-time side effects."
390;;; and we don't do much other than to make the function be defined,
391;;; which means that checking of callers' arglists can only occur after called
392;;; methods are actually loaded.
393(defmacro defmethod (name &rest args)
394  (multiple-value-bind (qualifiers lambda-list body)
395      (parse-defmethod args)
396    `(progn
397       (eval-when (:compile-toplevel :execute)
398         ;; :compile-toplevel is needed for subsequent forms
399         ;; :execute is needed for references to itself inside the body
400         (compile-or-load-defgeneric ',name))
401       ;; KLUDGE: this double expansion is quite a monumental
402       ;; workaround: it comes about because of a fantastic interaction
403       ;; between the processing rules of CLHS 3.2.3.1 and the
404       ;; bizarreness of MAKE-METHOD-LAMBDA.
405       ;;
406       ;; MAKE-METHOD-LAMBDA can be called by the user, and if the
407       ;; lambda itself doesn't refer to outside bindings the return
408       ;; value must be compileable in the null lexical environment.
409       ;; However, the function must also refer somehow to the
410       ;; associated method object, so that it can call NO-NEXT-METHOD
411       ;; with the appropriate arguments if there is no next method --
412       ;; but when the function is generated, the method object doesn't
413       ;; exist yet.
414       ;;
415       ;; In order to resolve this issue, we insert a literal cons cell
416       ;; into the body of the method lambda, return the same cons cell
417       ;; as part of the second (initargs) return value of
418       ;; MAKE-METHOD-LAMBDA, and a method on INITIALIZE-INSTANCE fills
419       ;; in the cell when the method is created.  However, this
420       ;; strategy depends on having a fresh cons cell for every method
421       ;; lambda, which (without the workaround below) is skewered by
422       ;; the processing in CLHS 3.2.3.1, which permits implementations
423       ;; to macroexpand the bodies of EVAL-WHEN forms with both
424       ;; :COMPILE-TOPLEVEL and :LOAD-TOPLEVEL only once.  The
425       ;; expansion below forces the double expansion in those cases,
426       ;; while expanding only once in the common case.
427       (eval-when (:load-toplevel)
428         (%defmethod-expander ,name ,qualifiers ,lambda-list ,body))
429       (eval-when (:execute)
430         (%defmethod-expander ,name ,qualifiers ,lambda-list ,body)))))
431
432(defmacro %defmethod-expander
433    (name qualifiers lambda-list body &environment env)
434  (multiple-value-bind (proto-gf proto-method)
435      (prototypes-for-make-method-lambda name)
436    (expand-defmethod name proto-gf proto-method qualifiers
437                      lambda-list body env)))
438
439
440(defun prototypes-for-make-method-lambda (name)
441  (if (not (eq **boot-state** 'complete))
442      (values nil nil)
443      (let ((gf? (and (fboundp name)
444                      (gdefinition name))))
445        (if (or (null gf?)
446                (not (generic-function-p gf?)))
447            (values (class-prototype (find-class 'standard-generic-function))
448                    (class-prototype (find-class 'standard-method)))
449            (values gf?
450                    (class-prototype (or (generic-function-method-class gf?)
451                                         (find-class 'standard-method))))))))
452
453;;; Take a name which is either a generic function name or a list specifying
454;;; a SETF generic function (like: (SETF <generic-function-name>)). Return
455;;; the prototype instance of the method-class for that generic function.
456;;;
457;;; If there is no generic function by that name, this returns the
458;;; default value, the prototype instance of the class
459;;; STANDARD-METHOD. This default value is also returned if the spec
460;;; names an ordinary function or even a macro. In effect, this leaves
461;;; the signalling of the appropriate error until load time.
462;;;
463;;; Note: During bootstrapping, this function is allowed to return NIL.
464(defun method-prototype-for-gf (name)
465  (let ((gf? (and (fboundp name)
466                  (gdefinition name))))
467    (cond ((neq **boot-state** 'complete) nil)
468          ((or (null gf?)
469               (not (generic-function-p gf?)))          ; Someone else MIGHT
470                                                        ; error at load time.
471           (class-prototype (find-class 'standard-method)))
472          (t
473            (class-prototype (or (generic-function-method-class gf?)
474                                 (find-class 'standard-method)))))))
475
476;;; These are used to communicate the method name and lambda-list to
477;;; MAKE-METHOD-LAMBDA-INTERNAL.
478(defvar *method-name* nil)
479(defvar *method-lambda-list* nil)
480
481(defun expand-defmethod (name proto-gf proto-method qualifiers lambda-list
482                         body env)
483  (binding* (;; ENV could be of type SB!INTERPRETER:BASIC-ENV but I
484             ;; don't care to figure out what parts of PCL would have
485             ;; to change to accept that, so coerce.
486             (env (sb-kernel:coerce-to-lexenv env))
487             ((nil unspecialized-lambda-list specializers)
488              (parse-specialized-lambda-list lambda-list))
489             (*method-name* `(,name ,@qualifiers ,specializers))
490             (method-lambda `(lambda ,unspecialized-lambda-list ,@body))
491             ((method-function-lambda initargs new-lambda-list)
492              (make-method-lambda-using-specializers
493               proto-gf proto-method qualifiers specializers method-lambda env))
494             (initargs-form
495              (make-method-initargs-form
496               proto-gf proto-method method-function-lambda initargs env))
497             (specializers-form
498              (make-method-specializers-form
499               proto-gf proto-method specializers env)))
500    (mapc (lambda (specializer)
501            (when (typep specializer 'type-specifier)
502              (check-deprecated-type specializer)))
503          specializers)
504    ;; Note: We could DECLAIM the ftype of the generic function here,
505    ;; since ANSI specifies that we create it if it does not
506    ;; exist. However, I chose not to, because I think it's more
507    ;; useful to support a style of programming where every generic
508    ;; function has an explicit DEFGENERIC and any typos in DEFMETHODs
509    ;; are warned about. Otherwise
510    ;;
511    ;;   (DEFGENERIC FOO-BAR-BLETCH (X))
512    ;;   (DEFMETHOD FOO-BAR-BLETCH ((X HASH-TABLE)) ..)
513    ;;   (DEFMETHOD FOO-BRA-BLETCH ((X SIMPLE-VECTOR)) ..)
514    ;;   (DEFMETHOD FOO-BAR-BLETCH ((X VECTOR)) ..)
515    ;;   (DEFMETHOD FOO-BAR-BLETCH ((X ARRAY)) ..)
516    ;;   (DEFMETHOD FOO-BAR-BLETCH ((X LIST)) ..)
517    ;;
518    ;; compiles without raising an error and runs without raising an
519    ;; error (since SIMPLE-VECTOR cases fall through to VECTOR) but
520    ;; still doesn't do what was intended. I hate that kind of bug
521    ;; (code which silently gives the wrong answer), so we don't do a
522    ;; DECLAIM here. -- WHN 20000229
523    (make-defmethod-form name qualifiers specializers-form
524                         (or new-lambda-list unspecialized-lambda-list)
525                         (if proto-method
526                             (class-name (class-of proto-method))
527                             'standard-method)
528                         initargs-form)))
529
530(defun interned-symbol-p (x)
531  (and (symbolp x) (symbol-package x)))
532
533(defun make-defmethod-form
534    (name qualifiers specializers unspecialized-lambda-list
535     method-class-name initargs-form)
536  (declare (sb-ext:muffle-conditions sb-ext:code-deletion-note))
537  (let (fn
538        fn-lambda)
539    (if (and (interned-symbol-p (fun-name-block-name name))
540             (every #'interned-symbol-p qualifiers)
541             (every (lambda (s)
542                      (if (consp s)
543                          (and (eq (car s) 'eql)
544                               (constantp (cadr s))
545                               (let ((sv (constant-form-value (cadr s))))
546                                 (or (interned-symbol-p sv)
547                                     (integerp sv)
548                                     (and (characterp sv)
549                                          (standard-char-p sv)))))
550                          (interned-symbol-p s)))
551                    specializers)
552             (consp initargs-form)
553             (eq (car initargs-form) 'list*)
554             (memq (cadr initargs-form) '(:function))
555             (consp (setq fn (caddr initargs-form)))
556             (eq (car fn) 'function)
557             (consp (setq fn-lambda (cadr fn)))
558             (eq (car fn-lambda) 'lambda)
559             (bug "Really got here"))
560        (let* ((specls (mapcar (lambda (specl)
561                                 (if (consp specl)
562                                     ;; CONSTANT-FORM-VALUE?  What I
563                                     ;; kind of want to know, though,
564                                     ;; is what happens if we don't do
565                                     ;; this for some slow-method
566                                     ;; function because of a hairy
567                                     ;; lexenv -- is the only bad
568                                     ;; effect that the method
569                                     ;; function ends up unnamed?  If
570                                     ;; so, couldn't we arrange to
571                                     ;; name it later?
572                                     `(,(car specl) ,(eval (cadr specl)))
573                                   specl))
574                               specializers))
575               (mname `(,(if (eq (cadr initargs-form) :function)
576                             'slow-method 'fast-method)
577                        ,name ,@qualifiers ,specls)))
578          `(progn
579             (defun ,mname ,(cadr fn-lambda)
580               ,@(cddr fn-lambda))
581             ,(make-defmethod-form-internal
582               name qualifiers `',specls
583               unspecialized-lambda-list method-class-name
584               `(list* ,(cadr initargs-form)
585                       #',mname
586                       ,@(cdddr initargs-form)))))
587        (make-defmethod-form-internal
588         name qualifiers
589         specializers
590         #+nil
591         `(list ,@(mapcar (lambda (specializer)
592                            (if (consp specializer)
593                                ``(,',(car specializer)
594                                      ,,(cadr specializer))
595                                `',specializer))
596                          specializers))
597         unspecialized-lambda-list
598         method-class-name
599         initargs-form))))
600
601(defun make-defmethod-form-internal
602    (name qualifiers specializers-form unspecialized-lambda-list
603     method-class-name initargs-form)
604  `(load-defmethod
605    ',method-class-name
606    ',name
607    ',qualifiers
608    ,specializers-form
609    ',unspecialized-lambda-list
610    ,initargs-form
611    (sb-c:source-location)))
612
613(defmacro make-method-function (method-lambda &environment env)
614  (binding* (((proto-gf proto-method)
615              (prototypes-for-make-method-lambda nil))
616             ((method-function-lambda initargs)
617              (make-method-lambda proto-gf proto-method method-lambda env))) ; FIXME: coerce-to-lexenv?
618    (make-method-initargs-form
619     proto-gf proto-method method-function-lambda initargs env)))
620
621(defun real-make-method-initargs-form (proto-gf proto-method
622                                       method-lambda initargs env)
623  (declare (ignore proto-gf proto-method))
624  (check-method-lambda method-lambda 'make-method-initargs)
625  (make-method-initargs-form-internal method-lambda initargs env))
626
627(unless (fboundp 'make-method-initargs-form)
628  (setf (gdefinition 'make-method-initargs-form)
629        (symbol-function 'real-make-method-initargs-form)))
630
631(defun real-make-method-lambda-using-specializers
632    (proto-gf proto-method qualifiers specializers method-lambda env)
633  (declare (ignore qualifiers))
634  (check-method-lambda method-lambda 'make-method-lambda) ; TODO remove check in make-method-lambda
635  ;; Default behavior: delegate to MAKE-METHOD-LAMBDA.
636  (let* ((lambda-list (second method-lambda))
637         (*method-lambda-list*
638          (append
639           (mapcar #'list (subseq lambda-list 0 (length specializers)) specializers)
640           (subseq lambda-list (length specializers)))))
641    (make-method-lambda proto-gf proto-method method-lambda env)))
642
643(unless (fboundp 'make-method-lambda-using-specializers)
644  (setf (gdefinition 'make-method-lambda-using-specializers)
645        (symbol-function 'real-make-method-lambda-using-specializers)))
646
647;;; When bootstrapping PCL MAKE-METHOD-LAMBDA starts out as a regular
648;;; function: REAL-MAKE-METHOD-LAMBDA set to the fdefinition of
649;;; MAKE-METHOD-LAMBDA. Once generic functions are born,
650;;; REAL-MAKE-METHOD-LAMBDA is used to implement the default method.
651;;; MAKE-METHOD-LAMBDA-INTERNAL is split out into a separate function
652;;; so that changing it in a live image is easy, and changes actually
653;;; take effect.
654(defun real-make-method-lambda (proto-gf proto-method method-lambda env)
655  (make-method-lambda-internal proto-gf proto-method method-lambda env))
656
657(unless (fboundp 'make-method-lambda)
658  (setf (gdefinition 'make-method-lambda)
659        (symbol-function 'real-make-method-lambda)))
660
661(defun declared-specials (declarations)
662  (loop for (declare . specifiers) in declarations
663        append (loop for specifier in specifiers
664                     when (eq 'special (car specifier))
665                     append (cdr specifier))))
666
667(defun make-method-lambda-internal (proto-gf proto-method method-lambda env)
668  (declare (ignore proto-gf proto-method))
669  (check-method-lambda method-lambda 'make-method-lambda)
670  (multiple-value-bind (real-body declarations documentation)
671      (parse-body (cddr method-lambda) t)
672    ;; We have the %METHOD-NAME declaration in the place where we expect it only
673    ;; if there is are no non-standard prior MAKE-METHOD-LAMBDA methods -- or
674    ;; unless they're fantastically unintrusive.
675    (let* ((method-name *method-name*)
676           (method-lambda-list *method-lambda-list*)
677           ;; Macroexpansion caused by code-walking may call make-method-lambda and
678           ;; end up with wrong values
679           (*method-name* nil)
680           (*method-lambda-list* nil)
681           (generic-function-name (when method-name (car method-name)))
682           (specialized-lambda-list (or method-lambda-list
683                                        (ecase (car method-lambda)
684                                          (lambda (second method-lambda))
685                                          (named-lambda (third method-lambda)))))
686           ;; the method-cell is a way of communicating what method a
687           ;; method-function implements, for the purpose of
688           ;; NO-NEXT-METHOD.  We need something that can be shared
689           ;; between function and initargs, but not something that
690           ;; will be coalesced as a constant (because we are naughty,
691           ;; oh yes) with the expansion of any other methods in the
692           ;; same file.  -- CSR, 2007-05-30
693           (method-cell (list (make-symbol "METHOD-CELL"))))
694      (multiple-value-bind (parameters lambda-list specializers)
695          (parse-specialized-lambda-list specialized-lambda-list)
696        (let* ((required-parameters
697                (mapcar (lambda (r s) (declare (ignore s)) r)
698                        parameters
699                        specializers))
700               (slots (mapcar #'list required-parameters))
701               (class-declarations
702                `(declare
703                  ;; These declarations seem to be used by PCL to pass
704                  ;; information to itself; when I tried to delete 'em
705                  ;; ca. 0.6.10 it didn't work. I'm not sure how
706                  ;; they work, but note the (VAR-DECLARATION '%CLASS ..)
707                  ;; expression in CAN-OPTIMIZE-ACCESS1. -- WHN 2000-12-30
708                  ,@(remove nil
709                            (mapcar (lambda (a s) (and (symbolp s)
710                                                       (neq s t)
711                                                       `(%class ,a ,s)))
712                                    parameters
713                                    specializers))
714                  ;; These TYPE declarations weren't in the original
715                  ;; PCL code, but the Python compiler likes them a
716                  ;; lot. (We're telling the compiler about our
717                  ;; knowledge of specialized argument types so that
718                  ;; it can avoid run-time type dispatch overhead,
719                  ;; which can be a huge win for Python.)
720                  ,@(let ((specials (declared-specials declarations)))
721                      (mapcar (lambda (par spec)
722                                (parameter-specializer-declaration-in-defmethod
723                                 par spec specials env))
724                              parameters
725                              specializers))))
726               (method-lambda
727                ;; Remove the documentation string and insert the
728                ;; appropriate class declarations. The documentation
729                ;; string is removed to make it easy for us to insert
730                ;; new declarations later, they will just go after the
731                ;; CADR of the method lambda. The class declarations
732                ;; are inserted to communicate the class of the method's
733                ;; arguments to the code walk.
734                `(lambda ,lambda-list
735                   ;; The default ignorability of method parameters
736                   ;; doesn't seem to be specified by ANSI. PCL had
737                   ;; them basically ignorable but was a little
738                   ;; inconsistent. E.g. even though the two
739                   ;; method definitions
740                   ;;   (DEFMETHOD FOO ((X T) (Y T)) "Z")
741                   ;;   (DEFMETHOD FOO ((X T) Y) "Z")
742                   ;; are otherwise equivalent, PCL treated Y as
743                   ;; ignorable in the first definition but not in the
744                   ;; second definition. We make all required
745                   ;; parameters ignorable as a way of systematizing
746                   ;; the old PCL behavior. -- WHN 2000-11-24
747                   (declare (ignorable ,@required-parameters))
748                   ,class-declarations
749                   ,@declarations
750                   (block ,(fun-name-block-name generic-function-name)
751                     ,@real-body)))
752               (constant-value-p (and (null (cdr real-body))
753                                      (constantp (car real-body))))
754               (constant-value (and constant-value-p
755                                    (constant-form-value (car real-body))))
756               (plist (and constant-value-p
757                           (or (typep constant-value
758                                      '(or number character))
759                               (and (symbolp constant-value)
760                                    (symbol-package constant-value)))
761                           (list :constant-value constant-value)))
762               (applyp (dolist (p lambda-list nil)
763                         (cond ((memq p '(&optional &rest &key))
764                                (return t))
765                               ((eq p '&aux)
766                                (return nil))))))
767          (multiple-value-bind (walked-lambda call-next-method-p setq-p
768                                parameters-setqd)
769              (walk-method-lambda method-lambda
770                                  required-parameters
771                                  env
772                                  slots)
773            (multiple-value-bind (walked-lambda-body
774                                  walked-declarations
775                                  walked-documentation)
776                (parse-body (cddr walked-lambda) t)
777              (declare (ignore walked-documentation))
778              (when (some #'cdr slots)
779                (let ((slot-name-lists (slot-name-lists-from-slots slots)))
780                  (setq plist
781                        `(,@(when slot-name-lists
782                                  `(:slot-name-lists ,slot-name-lists))
783                            ,@plist))
784                  (setq walked-lambda-body
785                        `((pv-binding (,required-parameters
786                                       ,slot-name-lists
787                                       (load-time-value
788                                        (intern-pv-table
789                                         :slot-name-lists ',slot-name-lists)))
790                            ,@walked-lambda-body)))))
791              (when (and (memq '&key lambda-list)
792                         (not (memq '&allow-other-keys lambda-list)))
793                (let ((aux (memq '&aux lambda-list)))
794                  (setq lambda-list (nconc (ldiff lambda-list aux)
795                                           (list '&allow-other-keys)
796                                           aux))))
797              (values `(lambda (.method-args. .next-methods.)
798                         (simple-lexical-method-functions
799                             (,lambda-list .method-args. .next-methods.
800                                           :call-next-method-p
801                                           ,(when call-next-method-p t)
802                                           :setq-p ,setq-p
803                                           :parameters-setqd ,parameters-setqd
804                                           :method-cell ,method-cell
805                                           :applyp ,applyp)
806                           ,@walked-declarations
807                           (locally
808                               (declare (disable-package-locks
809                                         %parameter-binding-modified))
810                             (symbol-macrolet ((%parameter-binding-modified
811                                                ',@parameters-setqd))
812                               (declare (enable-package-locks
813                                         %parameter-binding-modified))
814                               ,@walked-lambda-body))))
815                      `(,@(when call-next-method-p `(method-cell ,method-cell))
816                          ,@(when (member call-next-method-p '(:simple nil))
817                                  '(simple-next-method-call t))
818                          ,@(when plist `(plist ,plist))
819                          ,@(when documentation `(:documentation ,documentation)))))))))))
820
821(defun real-make-method-specializers-form
822    (proto-generic-function proto-method specializer-names environment)
823  (flet ((make-parse-form (name)
824           (make-specializer-form-using-class
825            proto-generic-function proto-method name environment)))
826    `(list ,@(mapcar #'make-parse-form specializer-names))))
827
828(unless (fboundp 'make-method-specializers-form)
829  (setf (gdefinition 'make-method-specializers-form)
830        (symbol-function 'real-make-method-specializers-form)))
831
832(defun real-make-specializer-form-using-class/t
833    (proto-generic-function proto-method specializer-name environment)
834  (declare (ignore proto-generic-function proto-method environment))
835  (error 'simple-reference-error
836         :format-control
837         "~@<~S is not a valid parameter specializer name.~@:>"
838         :format-arguments (list specializer-name)
839         :references (list '(:ansi-cl :macro defmethod)
840                           '(:ansi-cl :glossary "parameter specializer name"))))
841
842(defun real-make-specializer-form-using-class/specializer
843    (proto-generic-function proto-method specializer-name environment)
844  (declare (ignore proto-generic-function proto-method environment))
845  (when (eq **boot-state** 'complete)
846    specializer-name))
847
848(defun real-make-specializer-form-using-class/symbol
849    (proto-generic-function proto-method specializer-name environment)
850  (declare (ignore proto-generic-function proto-method environment))
851  `(find-class ',specializer-name))
852
853(defun real-make-specializer-form-using-class/cons
854    (proto-generic-function proto-method specializer-name environment)
855  (declare (ignore proto-generic-function proto-method environment))
856  ;; In case of unknown specializer or known specializer with syntax
857  ;; error, TYPECASE may fall through to default method with error
858  ;; signaling.
859  (typecase specializer-name
860    ((cons (eql eql) (cons t null))
861     `(intern-eql-specializer ,(second specializer-name)))
862    ((cons (eql class-eq) (cons t null))
863     `(class-eq-specializer (find-class ',(second specializer-name))))))
864
865(defun real-make-specializer-form-using-class
866    (proto-generic-function proto-method specializer-name environment)
867  (macrolet
868      ((delegations ()
869         `(typecase specializer-name
870            ,@(mapcar
871               (lambda (type)
872                 (let ((function-name
873                         (symbolicate
874                          'real-make-specializer-form-using-class '#:/ type)))
875                   `(,type
876                     (,function-name
877                      proto-generic-function proto-method specializer-name environment))))
878               '(; specializer
879                 ; ^ apparently not needed during bootstrapping
880                 symbol cons t)))))
881    (delegations)))
882
883(unless (fboundp 'make-specializer-form-using-class)
884  (setf (gdefinition 'make-specializer-form-using-class)
885        (symbol-function 'real-make-specializer-form-using-class)))
886
887(defun real-parse-specializer-using-class (generic-function specializer)
888  (let ((result (specializer-from-type specializer)))
889    (if (specializerp result)
890        result
891        (error "~@<~S cannot be parsed as a specializer for ~S.~@:>"
892               specializer generic-function))))
893
894(unless (fboundp 'parse-specializer-using-class)
895  (setf (gdefinition 'parse-specializer-using-class)
896        (symbol-function 'real-parse-specializer-using-class)))
897
898(defun real-unparse-specializer-using-class (generic-function specializer)
899  (if (specializerp specializer)
900      ;; FIXME: this HANDLER-CASE is a bit of a hammer to crack a nut:
901      ;; the idea is that we want to unparse permissively, so that the
902      ;; lazy (or rather the "portable") specializer extender (who
903      ;; does not define methods on these new SBCL-specific MOP
904      ;; functions) can still subclass specializer and define methods
905      ;; without everything going wrong.  Making it cleaner and
906      ;; clearer that that is what we are defending against would be
907      ;; nice.  -- CSR, 2007-06-01
908      (handler-case
909          (let ((type (specializer-type specializer)))
910            (if (and (consp type) (eq (car type) 'class))
911                (let* ((class (cadr type))
912                       (class-name (class-name class)))
913                  (if (eq class (find-class class-name nil))
914                      class-name
915                      type))
916                type))
917        (error () specializer))
918      (error "~@<~S is not a legal specializer for ~S.~@:>"
919             specializer generic-function)))
920
921(unless (fboundp 'unparse-specializer-using-class)
922  (setf (gdefinition 'unparse-specializer-using-class)
923        (symbol-function 'real-unparse-specializer-using-class)))
924
925;;; a helper function for creating Python-friendly type declarations
926;;; in DEFMETHOD forms.
927;;;
928;;; We're too lazy to cons up a new environment for this, so we just pass in
929;;; the list of locally declared specials in addition to the old environment.
930(defun parameter-specializer-declaration-in-defmethod
931    (parameter specializer specials env)
932  (cond ((and (consp specializer)
933              (eq (car specializer) 'eql))
934         ;; KLUDGE: ANSI, in its wisdom, says that
935         ;; EQL-SPECIALIZER-FORMs in EQL specializers are evaluated at
936         ;; DEFMETHOD expansion time. Thus, although one might think
937         ;; that in
938         ;;   (DEFMETHOD FOO ((X PACKAGE)
939         ;;                   (Y (EQL 12))
940         ;;      ..))
941         ;; the PACKAGE and (EQL 12) forms are both parallel type
942         ;; names, they're not, as is made clear when you do
943         ;;   (DEFMETHOD FOO ((X PACKAGE)
944         ;;                   (Y (EQL 'BAR)))
945         ;;     ..)
946         ;; where Y needs to be a symbol named "BAR", not some cons
947         ;; made by (CONS 'QUOTE 'BAR). I.e. when the
948         ;; EQL-SPECIALIZER-FORM is (EQL 'X), it requires an argument
949         ;; to be of type (EQL X). It'd be easy to transform one to
950         ;; the other, but it'd be somewhat messier to do so while
951         ;; ensuring that the EQL-SPECIALIZER-FORM is only EVAL'd
952         ;; once. (The new code wouldn't be messy, but it'd require a
953         ;; big transformation of the old code.) So instead we punt.
954         ;; -- WHN 20000610
955         '(ignorable))
956        ((member specializer
957                 ;; KLUDGE: For some low-level implementation
958                 ;; classes, perhaps because of some problems related
959                 ;; to the incomplete integration of PCL into SBCL's
960                 ;; type system, some specializer classes can't be
961                 ;; declared as argument types. E.g.
962                 ;;   (DEFMETHOD FOO ((X SLOT-OBJECT))
963                 ;;     (DECLARE (TYPE SLOT-OBJECT X))
964                 ;;     ..)
965                 ;; loses when
966                 ;;   (DEFSTRUCT BAR A B)
967                 ;;   (FOO (MAKE-BAR))
968                 ;; perhaps because of the way that STRUCTURE-OBJECT
969                 ;; inherits both from SLOT-OBJECT and from
970                 ;; SB-KERNEL:INSTANCE. In an effort to sweep such
971                 ;; problems under the rug, we exclude these problem
972                 ;; cases by blacklisting them here. -- WHN 2001-01-19
973                 (list 'slot-object #+nil (find-class 'slot-object)))
974         '(ignorable))
975        ((not (eq **boot-state** 'complete))
976         ;; KLUDGE: PCL, in its wisdom, sometimes calls methods with
977         ;; types which don't match their specializers. (Specifically,
978         ;; it calls ENSURE-CLASS-USING-CLASS (T NULL) with a non-NULL
979         ;; second argument.) Hopefully it only does this kind of
980         ;; weirdness when bootstrapping.. -- WHN 20000610
981         '(ignorable))
982        ((typep specializer 'eql-specializer)
983         `(type (eql ,(eql-specializer-object specializer)) ,parameter))
984        ((or (var-special-p parameter env) (member parameter specials))
985         ;; Don't declare types for special variables -- our rebinding magic
986         ;; for SETQ cases don't work right there as SET, (SETF SYMBOL-VALUE),
987         ;; etc. make things undecidable.
988         '(ignorable))
989        (t
990         ;; Otherwise, we can usually make Python very happy.
991         ;;
992         ;; KLUDGE: Since INFO doesn't work right for class objects here,
993         ;; and they are valid specializers, see if the specializer is
994         ;; a named class, and use the name in that case -- otherwise
995         ;; the class instance is ok, since info will just return NIL, NIL.
996         ;;
997         ;; We still need to deal with the class case too, but at
998         ;; least #.(find-class 'integer) and integer as equivalent
999         ;; specializers with this.
1000         (let* ((specializer-nameoid
1001                 (if (and (typep specializer 'class)
1002                          (let ((name (class-name specializer)))
1003                            (and name (symbolp name)
1004                                 (eq specializer (find-class name nil)))))
1005                     (class-name specializer)
1006                     specializer))
1007                (kind (info :type :kind specializer-nameoid)))
1008
1009           (flet ((specializer-nameoid-class ()
1010                    (typecase specializer-nameoid
1011                      (symbol (find-class specializer-nameoid nil))
1012                      (class specializer-nameoid)
1013                      (class-eq-specializer
1014                       (specializer-class specializer-nameoid))
1015                      (t nil))))
1016             (ecase kind
1017               ((:primitive) `(type ,specializer-nameoid ,parameter))
1018               ((:defined)
1019                (let ((class (specializer-nameoid-class)))
1020                  ;; CLASS can be null here if the user has
1021                  ;; erroneously tried to use a defined type as a
1022                  ;; specializer; it can be a non-SYSTEM-CLASS if
1023                  ;; the user defines a type and calls (SETF
1024                  ;; FIND-CLASS) in a consistent way.
1025                  (when (and class (typep class 'system-class))
1026                    `(type ,(class-name class) ,parameter))))
1027               ((:instance nil)
1028                (let ((class (specializer-nameoid-class)))
1029                  (cond
1030                    (class
1031                     (if (typep class '(or system-class structure-class))
1032                         `(type ,class ,parameter)
1033                         ;; don't declare CLOS classes as parameters;
1034                         ;; it's too expensive.
1035                         '(ignorable)))
1036                    (t
1037                     ;; we can get here, and still not have a failure
1038                     ;; case, by doing MOP programming like (PROGN
1039                     ;; (ENSURE-CLASS 'FOO) (DEFMETHOD BAR ((X FOO))
1040                     ;; ...)).  Best to let the user know we haven't
1041                     ;; been able to extract enough information:
1042                     (style-warn
1043                      "~@<can't find type for specializer ~S in ~S.~@:>"
1044                      specializer-nameoid
1045                      'parameter-specializer-declaration-in-defmethod)
1046                     '(ignorable)))))
1047               ((:forthcoming-defclass-type)
1048                '(ignorable))))))))
1049
1050;;; For passing a list (groveled by the walker) of the required
1051;;; parameters whose bindings are modified in the method body to the
1052;;; optimized-slot-value* macros.
1053(define-symbol-macro %parameter-binding-modified ())
1054
1055(defmacro simple-lexical-method-functions ((lambda-list
1056                                            method-args
1057                                            next-methods
1058                                            &rest lmf-options)
1059                                           &body body)
1060  `(progn
1061     ,method-args ,next-methods
1062     (bind-simple-lexical-method-functions (,method-args ,next-methods
1063                                                         ,lmf-options)
1064         (bind-args (,lambda-list ,method-args)
1065           ,@body))))
1066
1067(defmacro fast-lexical-method-functions ((lambda-list
1068                                          next-method-call
1069                                          args
1070                                          rest-arg
1071                                          &rest lmf-options)
1072                                         &body body)
1073  `(bind-fast-lexical-method-functions (,args ,rest-arg ,next-method-call ,lmf-options)
1074     (bind-args (,(nthcdr (length args) lambda-list) ,rest-arg)
1075       ,@body)))
1076
1077(defmacro bind-simple-lexical-method-functions
1078    ((method-args next-methods (&key call-next-method-p setq-p
1079                                     parameters-setqd applyp method-cell))
1080     &body body
1081     &environment env)
1082  (declare (ignore parameters-setqd))
1083  (if (not (or call-next-method-p setq-p applyp))
1084      ;; always provide the lexical function NEXT-METHOD-P.
1085      ;; I would think this to be a good candidate for declaring INLINE
1086      ;; but that's not the way it was done before.
1087      `(flet ((next-method-p () (not (null (car ,next-methods)))))
1088         (declare (ignorable #'next-method-p))
1089         ,@body)
1090      `(let ((.next-method. (car ,next-methods))
1091             (,next-methods (cdr ,next-methods)))
1092         (declare (ignorable .next-method. ,next-methods))
1093         (flet (,@(when call-next-method-p
1094                    `((call-next-method (&rest cnm-args)
1095                       (declare (dynamic-extent cnm-args))
1096                       ,@(if (safe-code-p env)
1097                             `((%check-cnm-args cnm-args
1098                                                ,method-args
1099                                                ',method-cell))
1100                             nil)
1101                       (if .next-method.
1102                           (funcall (if (std-instance-p .next-method.)
1103                                        (method-function .next-method.)
1104                                        .next-method.) ; for early methods
1105                                    (or cnm-args ,method-args)
1106                                    ,next-methods)
1107                           (apply #'call-no-next-method
1108                                  ',method-cell
1109                                  (or cnm-args ,method-args))))))
1110                (next-method-p () (not (null .next-method.))))
1111           (declare (ignorable #'next-method-p))
1112           ,@body))))
1113
1114(defun call-no-next-method (method-cell &rest args)
1115  (let ((method (car method-cell)))
1116    (aver method)
1117    ;; Can't easily provide a RETRY restart here, as the return value here is
1118    ;; for the method, not the generic function.
1119    (apply #'no-next-method (method-generic-function method)
1120           method args)))
1121
1122(defun call-no-applicable-method (gf args)
1123  (restart-case
1124          (apply #'no-applicable-method gf args)
1125    (retry ()
1126      :report "Retry calling the generic function."
1127      (apply gf args))))
1128
1129(defun call-no-primary-method (gf args)
1130  (restart-case
1131      (apply #'no-primary-method gf args)
1132    (retry ()
1133      :report "Retry calling the generic function."
1134      (apply gf args))))
1135
1136(defstruct (method-call (:copier nil))
1137  (function #'identity :type function)
1138  call-method-args)
1139(defstruct (constant-method-call (:copier nil) (:include method-call))
1140  value)
1141
1142#-sb-fluid (declaim (sb-ext:freeze-type method-call))
1143
1144(defmacro invoke-method-call1 (function args cm-args)
1145  `(let ((.function. ,function)
1146         (.args. ,args)
1147         (.cm-args. ,cm-args))
1148     (if (and .cm-args. (null (cdr .cm-args.)))
1149         (funcall .function. .args. (car .cm-args.))
1150         (apply .function. .args. .cm-args.))))
1151
1152(defmacro invoke-method-call (method-call restp &rest required-args+rest-arg)
1153  `(invoke-method-call1 (method-call-function ,method-call)
1154                        ,(if restp
1155                             `(list* ,@required-args+rest-arg)
1156                             `(list ,@required-args+rest-arg))
1157                        (method-call-call-method-args ,method-call)))
1158
1159(defstruct (fast-method-call (:copier nil))
1160  (function #'identity :type function)
1161  pv
1162  next-method-call
1163  arg-info)
1164(defstruct (constant-fast-method-call
1165             (:copier nil) (:include fast-method-call))
1166  value)
1167
1168#-sb-fluid (declaim (sb-ext:freeze-type fast-method-call))
1169
1170;; The two variants of INVOKE-FAST-METHOD-CALL differ in how REST-ARGs
1171;; are handled. The first one will get REST-ARG as a single list (as
1172;; the last argument), and will thus need to use APPLY. The second one
1173;; will get them as a &MORE argument, so we can pass the arguments
1174;; directly with MULTIPLE-VALUE-CALL and %MORE-ARG-VALUES.
1175
1176(defmacro invoke-fast-method-call (method-call restp &rest required-args+rest-arg)
1177  `(,(if restp 'apply 'funcall) (fast-method-call-function ,method-call)
1178                                (fast-method-call-pv ,method-call)
1179                                (fast-method-call-next-method-call ,method-call)
1180                                ,@required-args+rest-arg))
1181
1182(defmacro invoke-fast-method-call/more (method-call
1183                                        more-context
1184                                        more-count
1185                                        &rest required-args)
1186  (macrolet ((generate-call (n)
1187               ``(funcall (fast-method-call-function ,method-call)
1188                          (fast-method-call-pv ,method-call)
1189                          (fast-method-call-next-method-call ,method-call)
1190                          ,@required-args
1191                          ,@(loop for x below ,n
1192                                  collect `(sb-c::%more-arg ,more-context ,x)))))
1193    ;; The cases with only small amounts of required arguments passed
1194    ;; are probably very common, and special-casing speeds them up by
1195    ;; a factor of 2 with very little effect on the other
1196    ;; cases. Though it'd be nice to have the generic case be equally
1197    ;; fast.
1198    `(case ,more-count
1199       (0 ,(generate-call 0))
1200       (1 ,(generate-call 1))
1201       (t (multiple-value-call (fast-method-call-function ,method-call)
1202            (values (fast-method-call-pv ,method-call))
1203            (values (fast-method-call-next-method-call ,method-call))
1204            ,@required-args
1205            (sb-c::%more-arg-values ,more-context 0 ,more-count))))))
1206
1207(defstruct (fast-instance-boundp (:copier nil))
1208  (index 0 :type fixnum))
1209
1210#-sb-fluid (declaim (sb-ext:freeze-type fast-instance-boundp))
1211
1212(eval-when (:compile-toplevel :load-toplevel :execute)
1213  (defvar *allow-emf-call-tracing-p* nil)
1214  (defvar *enable-emf-call-tracing-p* #-sb-show nil #+sb-show t))
1215
1216;;;; effective method functions
1217
1218(defvar *emf-call-trace-size* 200)
1219(defvar *emf-call-trace* nil)
1220(defvar *emf-call-trace-index* 0)
1221
1222;;; This function was in the CMU CL version of PCL (ca Debian 2.4.8)
1223;;; without explanation. It appears to be intended for debugging, so
1224;;; it might be useful someday, so I haven't deleted it.
1225;;; But it isn't documented and isn't used for anything now, so
1226;;; I've conditionalized it out of the base system. -- WHN 19991213
1227#+sb-show
1228(defun show-emf-call-trace ()
1229  (when *emf-call-trace*
1230    (let ((j *emf-call-trace-index*)
1231          (*enable-emf-call-tracing-p* nil))
1232      (format t "~&(The oldest entries are printed first)~%")
1233      (dotimes-fixnum (i *emf-call-trace-size*)
1234        (let ((ct (aref *emf-call-trace* j)))
1235          (when ct (print ct)))
1236        (incf j)
1237        (when (= j *emf-call-trace-size*)
1238          (setq j 0))))))
1239
1240(defun trace-emf-call-internal (emf format args)
1241  (unless *emf-call-trace*
1242    (setq *emf-call-trace* (make-array *emf-call-trace-size*)))
1243  (setf (aref *emf-call-trace* *emf-call-trace-index*)
1244        (list* emf format args))
1245  (incf *emf-call-trace-index*)
1246  (when (= *emf-call-trace-index* *emf-call-trace-size*)
1247    (setq *emf-call-trace-index* 0)))
1248
1249(defmacro trace-emf-call (emf format args)
1250  (when *allow-emf-call-tracing-p*
1251    `(when *enable-emf-call-tracing-p*
1252       (trace-emf-call-internal ,emf ,format ,args))))
1253
1254(defmacro invoke-effective-method-function-fast
1255    (emf restp &key required-args rest-arg more-arg)
1256  `(progn
1257     (trace-emf-call ,emf ,restp (list ,@required-args rest-arg))
1258     ,(if more-arg
1259          `(invoke-fast-method-call/more ,emf
1260                                         ,@more-arg
1261                                         ,@required-args)
1262          `(invoke-fast-method-call ,emf
1263                                    ,restp
1264                                    ,@required-args
1265                                    ,@rest-arg))))
1266
1267(defun effective-method-optimized-slot-access-clause
1268    (emf restp required-args)
1269  ;; "What," you may wonder, "do these next two clauses do?" In that
1270  ;; case, you are not a PCL implementor, for they considered this to
1271  ;; be self-documenting.:-| Or CSR, for that matter, since he can
1272  ;; also figure it out by looking at it without breaking stride. For
1273  ;; the rest of us, though: From what the code is doing with .SLOTS.
1274  ;; and whatnot, evidently it's implementing SLOT-VALUEish and
1275  ;; GET-SLOT-VALUEish things. Then we can reason backwards and
1276  ;; conclude that setting EMF to a FIXNUM is an optimized way to
1277  ;; represent these slot access operations.
1278  (when (not restp)
1279    (let ((length (length required-args)))
1280      (cond ((= 1 length)
1281             `((fixnum
1282                (let* ((.slots. (get-slots-or-nil
1283                                 ,(car required-args)))
1284                       (value (when .slots. (clos-slots-ref .slots. ,emf))))
1285                  (if (eq value +slot-unbound+)
1286                      (slot-unbound-internal ,(car required-args)
1287                                             ,emf)
1288                      value)))))
1289            ((= 2 length)
1290             `((fixnum
1291                (let ((.new-value. ,(car required-args))
1292                      (.slots. (get-slots-or-nil
1293                                ,(cadr required-args))))
1294                  (when .slots.
1295                    (setf (clos-slots-ref .slots. ,emf) .new-value.)))))))
1296      ;; (In cmucl-2.4.8 there was a commented-out third ,@(WHEN
1297      ;; ...) clause here to handle SLOT-BOUNDish stuff. Since
1298      ;; there was no explanation and presumably the code is 10+
1299      ;; years stale, I simply deleted it. -- WHN)
1300      )))
1301
1302;;; Before SBCL 0.9.16.7 instead of
1303;;; INVOKE-NARROW-EFFECTIVE-METHOD-FUNCTION we passed a (THE (OR
1304;;; FUNCTION METHOD-CALL FAST-METHOD-CALL) EMF) form as the EMF. Now,
1305;;; to make less work for the compiler we take a path that doesn't
1306;;; involve the slot-accessor clause (where EMF is a FIXNUM) at all.
1307(macrolet ((def (name &optional narrow)
1308             `(defmacro ,name (emf restp &key required-args rest-arg more-arg)
1309                (unless (constantp restp)
1310                  (error "The RESTP argument is not constant."))
1311                (setq restp (constant-form-value restp))
1312                (with-unique-names (emf-n)
1313                  `(locally
1314                       (declare (optimize (sb-c:insert-step-conditions 0)))
1315                     (let ((,emf-n ,emf))
1316                       (trace-emf-call ,emf-n ,restp (list ,@required-args ,@rest-arg))
1317                       (etypecase ,emf-n
1318                         (fast-method-call
1319                          ,(if more-arg
1320                               `(invoke-fast-method-call/more ,emf-n
1321                                                              ,@more-arg
1322                                                              ,@required-args)
1323                               `(invoke-fast-method-call ,emf-n
1324                                                         ,restp
1325                                                         ,@required-args
1326                                                         ,@rest-arg)))
1327                         ,@,(unless narrow
1328                              `(effective-method-optimized-slot-access-clause
1329                                emf-n restp required-args))
1330                         (method-call
1331                          (invoke-method-call ,emf-n ,restp ,@required-args
1332                                              ,@rest-arg))
1333                         (function
1334                          ,(if restp
1335                               `(apply ,emf-n ,@required-args ,@rest-arg)
1336                               `(funcall ,emf-n ,@required-args
1337                                         ,@rest-arg))))))))))
1338  (def invoke-effective-method-function nil)
1339  (def invoke-narrow-effective-method-function t))
1340
1341(defun invoke-emf (emf args)
1342  (trace-emf-call emf t args)
1343  (etypecase emf
1344    (fast-method-call
1345     (let* ((arg-info (fast-method-call-arg-info emf))
1346            (restp (cdr arg-info))
1347            (nreq (car arg-info)))
1348       (if restp
1349           (apply (fast-method-call-function emf)
1350                  (fast-method-call-pv emf)
1351                  (fast-method-call-next-method-call emf)
1352                  args)
1353           (cond ((null args)
1354                  (if (eql nreq 0)
1355                      (invoke-fast-method-call emf nil)
1356                      (error 'simple-program-error
1357                             :format-control "invalid number of arguments: 0"
1358                             :format-arguments nil)))
1359                 ((null (cdr args))
1360                  (if (eql nreq 1)
1361                      (invoke-fast-method-call emf nil (car args))
1362                      (error 'simple-program-error
1363                             :format-control "invalid number of arguments: 1"
1364                             :format-arguments nil)))
1365                 ((null (cddr args))
1366                  (if (eql nreq 2)
1367                      (invoke-fast-method-call emf nil (car args) (cadr args))
1368                      (error 'simple-program-error
1369                             :format-control "invalid number of arguments: 2"
1370                             :format-arguments nil)))
1371                 (t
1372                  (apply (fast-method-call-function emf)
1373                         (fast-method-call-pv emf)
1374                         (fast-method-call-next-method-call emf)
1375                         args))))))
1376    (method-call
1377     (apply (method-call-function emf)
1378            args
1379            (method-call-call-method-args emf)))
1380    (fixnum
1381     (cond ((null args)
1382            (error 'simple-program-error
1383                   :format-control "invalid number of arguments: 0"
1384                   :format-arguments nil))
1385           ((null (cdr args))
1386            (let* ((slots (get-slots (car args)))
1387                   (value (clos-slots-ref slots emf)))
1388              (if (eq value +slot-unbound+)
1389                  (slot-unbound-internal (car args) emf)
1390                  value)))
1391           ((null (cddr args))
1392            (setf (clos-slots-ref (get-slots (cadr args)) emf)
1393                  (car args)))
1394           (t (error 'simple-program-error
1395                     :format-control "invalid number of arguments"
1396                     :format-arguments nil))))
1397    (fast-instance-boundp
1398     (if (or (null args) (cdr args))
1399         (error 'simple-program-error
1400                :format-control "invalid number of arguments"
1401                :format-arguments nil)
1402         (let ((slots (get-slots (car args))))
1403           (not (eq (clos-slots-ref slots (fast-instance-boundp-index emf))
1404                    +slot-unbound+)))))
1405    (function
1406     (apply emf args))))
1407
1408
1409(defmacro fast-call-next-method-body ((args next-method-call rest-arg)
1410                                      method-cell
1411                                      cnm-args)
1412  `(if ,next-method-call
1413       ,(let ((call `(invoke-narrow-effective-method-function
1414                      ,next-method-call
1415                      ,(not (null rest-arg))
1416                      :required-args ,args
1417                      :rest-arg ,(when rest-arg (list rest-arg)))))
1418             `(if ,cnm-args
1419                  (bind-args ((,@args
1420                               ,@(when rest-arg
1421                                       `(&rest ,rest-arg)))
1422                              ,cnm-args)
1423                    ,call)
1424                  ,call))
1425       (call-no-next-method ',method-cell
1426                            ,@args
1427                            ,@(when rest-arg
1428                                    `(,rest-arg)))))
1429
1430(defmacro bind-fast-lexical-method-functions
1431    ((args rest-arg next-method-call (&key
1432                                      call-next-method-p
1433                                      setq-p
1434                                      parameters-setqd
1435                                      method-cell
1436                                      applyp))
1437     &body body
1438     &environment env)
1439  (let* ((next-method-p-def
1440          `((next-method-p ()
1441              (declare (optimize (sb-c:insert-step-conditions 0)))
1442              (not (null ,next-method-call)))))
1443         (rebindings (when (or setq-p call-next-method-p)
1444                       (mapcar (lambda (x) (list x x)) parameters-setqd))))
1445    (if (not (or call-next-method-p setq-p applyp))
1446        `(flet ,next-method-p-def
1447           (declare (ignorable #'next-method-p))
1448           ,@body)
1449        `(flet (,@(when call-next-method-p
1450                    `((call-next-method (&rest cnm-args)
1451                        (declare (dynamic-extent cnm-args)
1452                                 (muffle-conditions code-deletion-note)
1453                                 (optimize (sb-c:insert-step-conditions 0)))
1454                        ,@(if (safe-code-p env)
1455                              `((%check-cnm-args cnm-args (list ,@args)
1456                                                 ',method-cell))
1457                              nil)
1458                        (fast-call-next-method-body (,args
1459                                                     ,next-method-call
1460                                                     ,rest-arg)
1461                            ,method-cell
1462                            cnm-args))))
1463                ,@next-method-p-def)
1464           (declare (ignorable #'next-method-p))
1465           (let ,rebindings
1466             ,@body)))))
1467
1468;;; CMUCL comment (Gerd Moellmann):
1469;;;
1470;;; The standard says it's an error if CALL-NEXT-METHOD is called with
1471;;; arguments, and the set of methods applicable to those arguments is
1472;;; different from the set of methods applicable to the original
1473;;; method arguments.  (According to Barry Margolin, this rule was
1474;;; probably added to ensure that before and around methods are always
1475;;; run before primary methods.)
1476;;;
1477;;; This could be optimized for the case that the generic function
1478;;; doesn't have hairy methods, does have standard method combination,
1479;;; is a standard generic function, there are no methods defined on it
1480;;; for COMPUTE-APPLICABLE-METHODS and probably a lot more of such
1481;;; preconditions.  That looks hairy and is probably not worth it,
1482;;; because this check will never be fast.
1483(defun %check-cnm-args (cnm-args orig-args method-cell)
1484  ;; 1. Check for no arguments.
1485  (when cnm-args
1486    (let* ((gf (method-generic-function (car method-cell)))
1487           (nreq (generic-function-nreq gf)))
1488      (declare (fixnum nreq))
1489      ;; 2. Requirement arguments pairwise: if all are EQL, the applicable
1490      ;; methods must be the same. This takes care of the relatively common
1491      ;; case of twiddling with &KEY arguments without being horribly
1492      ;; expensive.
1493      (unless (do ((orig orig-args (cdr orig))
1494                   (args cnm-args (cdr args))
1495                   (n nreq (1- nreq)))
1496                  ((zerop n) t)
1497                (unless (and orig args (eql (car orig) (car args)))
1498                  (return nil)))
1499        ;; 3. Only then do the full check.
1500        (let ((omethods (compute-applicable-methods gf orig-args))
1501              (nmethods (compute-applicable-methods gf cnm-args)))
1502          (unless (equal omethods nmethods)
1503            (error "~@<The set of methods ~S applicable to argument~P ~
1504                    ~{~S~^, ~} to call-next-method is different from ~
1505                    the set of methods ~S applicable to the original ~
1506                    method argument~P ~{~S~^, ~}.~@:>"
1507                   nmethods (length cnm-args) cnm-args omethods
1508                   (length orig-args) orig-args)))))))
1509
1510;; FIXME: replacing this entire mess with DESTRUCTURING-BIND would correct
1511;; problems similar to those already solved by a correct implementation
1512;; of DESTRUCTURING-BIND, such as incorrect binding order:
1513;; e.g. (macroexpand-1 '(bind-args ((&optional (x nil xsp)) args) (form)))
1514;;      -> (LET* ((.ARGS-TAIL. ARGS) (XSP (NOT (NULL .ARGS-TAIL.))) (X ...)))
1515;; It's mostly irrelevant unless a method uses CALL-NEXT-METHOD though.
1516(defmacro bind-args ((lambda-list args) &body body)
1517  (let ((args-tail '.args-tail.)
1518        (key '.key.)
1519        (state 'required))
1520    (flet ((process-var (var)
1521             (if (memq var lambda-list-keywords)
1522                 (progn
1523                   (case var
1524                     (&optional       (setq state 'optional))
1525                     (&key            (setq state 'key))
1526                     (&allow-other-keys)
1527                     (&rest           (setq state 'rest))
1528                     (&aux            (setq state 'aux))
1529                     (otherwise
1530                      (error
1531                       "encountered the non-standard lambda list keyword ~S"
1532                       var)))
1533                   nil)
1534                 (case state
1535                   (required `((,var (pop ,args-tail))))
1536                   (optional (cond ((not (consp var))
1537                                    `((,var (when ,args-tail
1538                                              (pop ,args-tail)))))
1539                                   ((null (cddr var))
1540                                    `((,(car var) (if ,args-tail
1541                                                      (pop ,args-tail)
1542                                                      ,(cadr var)))))
1543                                   (t
1544                                    `((,(caddr var) (not (null ,args-tail)))
1545                                      (,(car var) (if ,args-tail
1546                                                      (pop ,args-tail)
1547                                                      ,(cadr var)))))))
1548                   (rest `((,var ,args-tail)))
1549                   (key (cond ((not (consp var))
1550                               `((,var (car
1551                                        (get-key-arg-tail ,(keywordicate var)
1552                                                          ,args-tail)))))
1553                              ((null (cddr var))
1554                               (multiple-value-bind (keyword variable)
1555                                   (if (consp (car var))
1556                                       (values (caar var)
1557                                               (cadar var))
1558                                       (values (keywordicate (car var))
1559                                               (car var)))
1560                                 `((,key (get-key-arg-tail ',keyword
1561                                                           ,args-tail))
1562                                   (,variable (if ,key
1563                                                  (car ,key)
1564                                                  ,(cadr var))))))
1565                              (t
1566                               (multiple-value-bind (keyword variable)
1567                                   (if (consp (car var))
1568                                       (values (caar var)
1569                                               (cadar var))
1570                                       (values (keywordicate (car var))
1571                                               (car var)))
1572                                 `((,key (get-key-arg-tail ',keyword
1573                                                           ,args-tail))
1574                                   (,(caddr var) (not (null,key)))
1575                                   (,variable (if ,key
1576                                                  (car ,key)
1577                                                  ,(cadr var))))))))
1578                   (aux `(,var))))))
1579      (let ((bindings (mapcan #'process-var lambda-list)))
1580        `(let* ((,args-tail ,args)
1581                ,@bindings
1582                (.dummy0.
1583                 ,@(when (eq state 'optional)
1584                     `((unless (null ,args-tail)
1585                         (error 'simple-program-error
1586                                :format-control "surplus arguments: ~S"
1587                                :format-arguments (list ,args-tail)))))))
1588           (declare (ignorable ,args-tail .dummy0.))
1589           ,@body)))))
1590
1591(defun get-key-arg-tail (keyword list)
1592  (loop for (key . tail) on list by #'cddr
1593        when (null tail) do
1594          ;; FIXME: Do we want to export this symbol? Or maybe use an
1595          ;; (ERROR 'SIMPLE-PROGRAM-ERROR) form?
1596          (sb-c::%odd-key-args-error)
1597        when (eq key keyword)
1598          return tail))
1599
1600(defun walk-method-lambda (method-lambda required-parameters env slots)
1601  (let (;; flag indicating that CALL-NEXT-METHOD should be in the
1602        ;; method definition
1603        (call-next-method-p nil)
1604        ;; a list of all required parameters whose bindings might be
1605        ;; modified in the method body.
1606        (parameters-setqd nil))
1607    (flet ((walk-function (form context env)
1608             (unless (and (eq context :eval) (consp form))
1609               (return-from walk-function form))
1610             (case (car form)
1611               (call-next-method
1612                    ;; hierarchy: nil -> :simple -> T.
1613                    (unless (eq call-next-method-p t)
1614                      (setq call-next-method-p (if (cdr form) t :simple)))
1615                    form)
1616               ((setq multiple-value-setq)
1617                    ;; The walker will split (SETQ A 1 B 2) to
1618                    ;; separate (SETQ A 1) and (SETQ B 2) forms, so we
1619                    ;; only need to handle the simple case of SETQ
1620                    ;; here.
1621                    (let ((vars (if (eq (car form) 'setq)
1622                                    (list (second form))
1623                                    (second form))))
1624                      (dolist (var vars)
1625                        ;; Note that we don't need to check for
1626                        ;; %VARIABLE-REBINDING declarations like is
1627                        ;; done in CAN-OPTIMIZE-ACCESS1, since the
1628                        ;; bindings that will have that declation will
1629                        ;; never be SETQd.
1630                        (when (var-declaration '%class var env)
1631                          ;; If a parameter binding is shadowed by
1632                          ;; another binding it won't have a %CLASS
1633                          ;; declaration anymore, and this won't get
1634                          ;; executed.
1635                          (pushnew var parameters-setqd :test #'eq))))
1636                    form)
1637               (function
1638                (when (equal (cdr form) '(call-next-method))
1639                  (setq call-next-method-p t))
1640                form)
1641               ((slot-value set-slot-value slot-boundp)
1642                (if (constantp (third form) env)
1643                    (let ((fun (ecase (car form)
1644                                 (slot-value #'optimize-slot-value)
1645                                 (set-slot-value #'optimize-set-slot-value)
1646                                 (slot-boundp #'optimize-slot-boundp))))
1647                      (funcall fun form slots required-parameters env))
1648                    form))
1649               (t form))))
1650
1651      (let ((walked-lambda (walk-form method-lambda env #'walk-function)))
1652        ;;; FIXME: the walker's rewriting of the source code causes
1653        ;;; trouble when doing code coverage. The rewrites should be
1654        ;;; removed, and the same operations done using
1655        ;;; compiler-macros or tranforms.
1656        (values (if (sb-c:policy env (= sb-c:store-coverage-data 0))
1657                    walked-lambda
1658                    method-lambda)
1659                call-next-method-p
1660                (not (null parameters-setqd))
1661                parameters-setqd)))))
1662
1663(defun generic-function-name-p (name)
1664  (and (legal-fun-name-p name)
1665       (fboundp name)
1666       (if (eq **boot-state** 'complete)
1667           (standard-generic-function-p (gdefinition name))
1668           (funcallable-instance-p (gdefinition name)))))
1669
1670(defun method-plist-value (method key &optional default)
1671  (let ((plist (if (consp method)
1672                   (getf (early-method-initargs method) 'plist)
1673                   (object-plist method))))
1674    (getf plist key default)))
1675
1676(defun (setf method-plist-value) (new-value method key &optional default)
1677  (if (consp method)
1678      (setf (getf (getf (early-method-initargs method) 'plist) key default)
1679            new-value)
1680      (setf (getf (object-plist method) key default) new-value)))
1681
1682(defun load-defmethod (class name quals specls ll initargs source-location)
1683  (let ((method-cell (getf initargs 'method-cell)))
1684    (setq initargs (copy-tree initargs))
1685    (when method-cell
1686      (setf (getf initargs 'method-cell) method-cell))
1687    #+nil
1688    (setf (getf (getf initargs 'plist) :name)
1689          (make-method-spec name quals specls))
1690    (load-defmethod-internal class name quals specls
1691                             ll initargs source-location)))
1692
1693(defun load-defmethod-internal
1694    (method-class gf-spec qualifiers specializers lambda-list
1695                  initargs source-location)
1696  (when (and (eq **boot-state** 'complete)
1697             (fboundp gf-spec))
1698    (let* ((gf (fdefinition gf-spec))
1699           (method (and (generic-function-p gf)
1700                        (generic-function-methods gf)
1701                        (find-method gf qualifiers specializers nil))))
1702      (when method
1703        (warn 'sb-kernel:redefinition-with-defmethod
1704              :name gf-spec
1705              :new-location source-location
1706              :old-method method
1707              :qualifiers qualifiers :specializers specializers))))
1708  (let ((method (apply #'add-named-method
1709                       gf-spec qualifiers specializers lambda-list
1710                       :definition-source source-location
1711                       initargs)))
1712    (unless (or (eq method-class 'standard-method)
1713                (eq (find-class method-class nil) (class-of method)))
1714      ;; FIXME: should be STYLE-WARNING?
1715      (format *error-output*
1716              "~&At the time the method with qualifiers ~:S and~%~
1717               specializers ~:S on the generic function ~S~%~
1718               was compiled, the method-class for that generic function was~%~
1719               ~S. But, the method class is now ~S, this~%~
1720               may mean that this method was compiled improperly.~%"
1721              qualifiers specializers gf-spec
1722              method-class (class-name (class-of method))))
1723    method))
1724
1725(defun make-method-spec (gf qualifiers specializers)
1726  (let ((name (generic-function-name gf))
1727        (unparsed-specializers (unparse-specializers gf specializers)))
1728    `(slow-method ,name ,@qualifiers ,unparsed-specializers)))
1729
1730(defun initialize-method-function (initargs method)
1731  (let* ((mf (getf initargs :function))
1732         (mff (and (typep mf '%method-function)
1733                   (%method-function-fast-function mf)))
1734         (plist (getf initargs 'plist))
1735         (name (getf plist :name))
1736         (method-cell (getf initargs 'method-cell)))
1737    (when method-cell
1738      (setf (car method-cell) method))
1739    (when name
1740      (when mf
1741        (setq mf (set-fun-name mf name)))
1742      (when (and mff (consp name) (eq (car name) 'slow-method))
1743        (let ((fast-name `(fast-method ,@(cdr name))))
1744          (set-fun-name mff fast-name))))
1745    (when plist
1746      (let ((plist plist))
1747        (let ((snl (getf plist :slot-name-lists)))
1748          (when snl
1749            (setf (method-plist-value method :pv-table)
1750                  (intern-pv-table :slot-name-lists snl))))))))
1751
1752(defun analyze-lambda-list (lambda-list)
1753  (multiple-value-bind (llks required optional rest keywords)
1754      ;; We say "&MUMBLE is not allowed in a generic function lambda list"
1755      ;; whether this is called by DEFMETHOD or DEFGENERIC.
1756      ;; [It is used for either. Why else recognize and silently ignore &AUX?]
1757      (parse-lambda-list lambda-list
1758                         :accept (lambda-list-keyword-mask
1759                                    '(&optional &rest &key &allow-other-keys &aux))
1760                         :silent t
1761                         :context "a generic function lambda list")
1762    (declare (ignore rest))
1763    (values llks (length required) (length optional)
1764            (mapcar #'parse-key-arg-spec keywords) keywords)))
1765
1766;; FIXME: this does more than return an FTYPE from a lambda list -
1767;; it unions the type with an existing ctype object. It needs a better name,
1768;; and to be reimplemented as "union and call sb-c::ftype-from-lambda-list".
1769(defun ftype-declaration-from-lambda-list (lambda-list name)
1770  (multiple-value-bind (llks nrequired noptional keywords keyword-parameters)
1771      (analyze-lambda-list lambda-list)
1772    (declare (ignore keyword-parameters))
1773    (let* ((old (proclaimed-ftype name)) ;FIXME:FDOCUMENTATION instead?
1774           (old-ftype (if (fun-type-p old) old nil))
1775           (old-restp (and old-ftype (fun-type-rest old-ftype)))
1776           (old-keys (and old-ftype
1777                          (mapcar #'key-info-name
1778                                  (fun-type-keywords
1779                                   old-ftype))))
1780           (old-keysp (and old-ftype (fun-type-keyp old-ftype)))
1781           (old-allowp (and old-ftype
1782                            (fun-type-allowp old-ftype)))
1783           (keywords (union old-keys (mapcar #'parse-key-arg-spec keywords))))
1784      `(function ,(append (make-list nrequired :initial-element t)
1785                          (when (plusp noptional)
1786                            (append '(&optional)
1787                                    (make-list noptional :initial-element t)))
1788                          (when (or (ll-kwds-restp llks) old-restp)
1789                            '(&rest t))
1790                          (when (or (ll-kwds-keyp llks) old-keysp)
1791                            (append '(&key)
1792                                    (mapcar (lambda (key)
1793                                              `(,key t))
1794                                            keywords)
1795                                    (when (or (ll-kwds-allowp llks) old-allowp)
1796                                      '(&allow-other-keys)))))
1797                 *))))
1798
1799;;;; early generic function support
1800
1801(defvar *!early-generic-functions* ())
1802
1803;; CLHS doesn't specify &allow-other-keys here but I guess the supposition
1804;; is that they'll be checked by ENSURE-GENERIC-FUNCTION-USING-CLASS.
1805;; Except we don't do that either, so I think the blame, if any, lies there
1806;; for not catching errant keywords.
1807(defun ensure-generic-function (fun-name &rest all-keys)
1808  (let ((existing (and (fboundp fun-name)
1809                       (gdefinition fun-name))))
1810    (cond ((and existing
1811                (eq **boot-state** 'complete)
1812                (null (generic-function-p existing)))
1813           (generic-clobbers-function fun-name)
1814           (fmakunbound fun-name)
1815           (apply #'ensure-generic-function fun-name all-keys))
1816          (t
1817           (apply #'ensure-generic-function-using-class
1818                  existing fun-name all-keys)))))
1819
1820(defun generic-clobbers-function (fun-name)
1821  (cerror "Replace the function binding"
1822          'simple-program-error
1823          :format-control "~@<~/sb-impl:print-symbol-with-prefix/ ~
1824                           already names an ordinary function or a ~
1825                           macro.~@:>"
1826          :format-arguments (list fun-name)))
1827
1828(defvar *sgf-wrapper*
1829  (!boot-make-wrapper (early-class-size 'standard-generic-function)
1830                      'standard-generic-function))
1831
1832(defvar *sgf-slots-init*
1833  (mapcar (lambda (canonical-slot)
1834            (if (memq (getf canonical-slot :name) '(arg-info source))
1835                +slot-unbound+
1836                (let ((initfunction (getf canonical-slot :initfunction)))
1837                  (if initfunction
1838                      (funcall initfunction)
1839                      +slot-unbound+))))
1840          (early-collect-inheritance 'standard-generic-function)))
1841
1842(defconstant +sgf-method-class-index+
1843  (!bootstrap-slot-index 'standard-generic-function 'method-class))
1844
1845(defun early-gf-p (x)
1846  (and (fsc-instance-p x)
1847       (eq (clos-slots-ref (get-slots x) +sgf-method-class-index+)
1848           +slot-unbound+)))
1849
1850(defconstant +sgf-methods-index+
1851  (!bootstrap-slot-index 'standard-generic-function 'methods))
1852
1853(defmacro early-gf-methods (gf)
1854  `(clos-slots-ref (get-slots ,gf) +sgf-methods-index+))
1855
1856(defun safe-generic-function-methods (generic-function)
1857  (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1858      (clos-slots-ref (get-slots generic-function) +sgf-methods-index+)
1859      (generic-function-methods generic-function)))
1860
1861(defconstant +sgf-arg-info-index+
1862  (!bootstrap-slot-index 'standard-generic-function 'arg-info))
1863
1864(defmacro early-gf-arg-info (gf)
1865  `(clos-slots-ref (get-slots ,gf) +sgf-arg-info-index+))
1866
1867(defconstant +sgf-dfun-state-index+
1868  (!bootstrap-slot-index 'standard-generic-function 'dfun-state))
1869
1870(defstruct (arg-info
1871            (:conc-name nil)
1872            (:constructor make-arg-info ())
1873            (:copier nil))
1874  (arg-info-lambda-list :no-lambda-list)
1875  arg-info-precedence
1876  arg-info-metatypes
1877  arg-info-number-optional
1878  arg-info-key/rest-p
1879  arg-info-keys   ;nil        no &KEY or &REST allowed
1880                  ;(k1 k2 ..) Each method must accept these &KEY arguments.
1881                  ;T          must have &KEY or &REST
1882
1883  gf-info-simple-accessor-type ; nil, reader, writer, boundp
1884  (gf-precompute-dfun-and-emf-p nil) ; set by set-arg-info
1885
1886  gf-info-static-c-a-m-emf
1887  (gf-info-c-a-m-emf-std-p t)
1888  gf-info-fast-mf-p)
1889
1890#-sb-fluid (declaim (sb-ext:freeze-type arg-info))
1891
1892(defun arg-info-valid-p (arg-info)
1893  (not (null (arg-info-number-optional arg-info))))
1894
1895(defun arg-info-applyp (arg-info)
1896  (or (plusp (arg-info-number-optional arg-info))
1897      (arg-info-key/rest-p arg-info)))
1898
1899(defun arg-info-number-required (arg-info)
1900  (length (arg-info-metatypes arg-info)))
1901
1902(defun arg-info-nkeys (arg-info)
1903  (count-if (lambda (x) (neq x t)) (arg-info-metatypes arg-info)))
1904
1905(defun create-gf-lambda-list (lambda-list)
1906  ;;; Create a gf lambda list from a method lambda list
1907  (loop for x in lambda-list
1908        collect (if (consp x) (list (car x)) x)
1909        if (eq x '&key) do (loop-finish)))
1910
1911(defun ll-keyp-or-restp (bits)
1912  (logtest (lambda-list-keyword-mask '(&key &rest)) bits))
1913
1914(defun set-arg-info (gf &key new-method (lambda-list nil lambda-list-p)
1915                        argument-precedence-order)
1916  (let* ((arg-info (if (eq **boot-state** 'complete)
1917                       (gf-arg-info gf)
1918                       (early-gf-arg-info gf)))
1919         (methods (if (eq **boot-state** 'complete)
1920                      (generic-function-methods gf)
1921                      (early-gf-methods gf)))
1922         (was-valid-p (integerp (arg-info-number-optional arg-info)))
1923         (first-p (and new-method (null (cdr methods)))))
1924    (when (and (not lambda-list-p) methods)
1925      (setq lambda-list (gf-lambda-list gf)))
1926    (when (or lambda-list-p
1927              (and first-p
1928                   (eq (arg-info-lambda-list arg-info) :no-lambda-list)))
1929      (multiple-value-bind (llks nreq nopt keywords)
1930          (analyze-lambda-list lambda-list)
1931        (when (and methods (not first-p))
1932          (let ((gf-nreq (arg-info-number-required arg-info))
1933                (gf-nopt (arg-info-number-optional arg-info))
1934                (gf-key/rest-p (arg-info-key/rest-p arg-info)))
1935            (unless (and (= nreq gf-nreq)
1936                         (= nopt gf-nopt)
1937                         (eq (ll-keyp-or-restp llks) gf-key/rest-p))
1938              (error "The lambda-list ~S is incompatible with ~
1939                     existing methods of ~S."
1940                     lambda-list gf))))
1941        (setf (arg-info-lambda-list arg-info)
1942              (if lambda-list-p
1943                  lambda-list
1944                   (create-gf-lambda-list lambda-list)))
1945        (when (or lambda-list-p argument-precedence-order
1946                  (null (arg-info-precedence arg-info)))
1947          (setf (arg-info-precedence arg-info)
1948                (compute-precedence lambda-list nreq argument-precedence-order)))
1949        (setf (arg-info-metatypes arg-info) (make-list nreq))
1950        (setf (arg-info-number-optional arg-info) nopt)
1951        (setf (arg-info-key/rest-p arg-info) (ll-keyp-or-restp llks))
1952        (setf (arg-info-keys arg-info)
1953              (if lambda-list-p
1954                  (if (ll-kwds-allowp llks) t keywords)
1955                  (arg-info-key/rest-p arg-info)))))
1956    (when new-method
1957      (check-method-arg-info gf arg-info new-method))
1958    (set-arg-info1 gf arg-info new-method methods was-valid-p first-p)
1959    arg-info))
1960
1961(defun check-method-arg-info (gf arg-info method)
1962  (multiple-value-bind (llks nreq nopt keywords)
1963      (analyze-lambda-list (if (consp method)
1964                               (early-method-lambda-list method)
1965                               (method-lambda-list method)))
1966    (flet ((lose (string &rest args)
1967             (error 'simple-program-error
1968                    :format-control "~@<attempt to add the method~2I~_~S~I~_~
1969                                     to the generic function~2I~_~S;~I~_~
1970                                     but ~?~:>"
1971                    :format-arguments (list method gf string args)))
1972           (comparison-description (x y)
1973             (if (> x y) "more" "fewer")))
1974      (let ((gf-nreq (arg-info-number-required arg-info))
1975            (gf-nopt (arg-info-number-optional arg-info))
1976            (gf-key/rest-p (arg-info-key/rest-p arg-info))
1977            (gf-keywords (arg-info-keys arg-info)))
1978        (unless (= nreq gf-nreq)
1979          (lose
1980           "the method has ~A required arguments than the generic function."
1981           (comparison-description nreq gf-nreq)))
1982        (unless (= nopt gf-nopt)
1983          (lose
1984           "the method has ~A optional arguments than the generic function."
1985           (comparison-description nopt gf-nopt)))
1986        (unless (eq (ll-keyp-or-restp llks) gf-key/rest-p)
1987          (lose
1988           "the method and generic function differ in whether they accept~_~
1989            &REST or &KEY arguments."))
1990        (when (consp gf-keywords)
1991          (unless (or (and (ll-kwds-restp llks) (not (ll-kwds-keyp llks)))
1992                      (ll-kwds-allowp llks)
1993                      (every (lambda (k) (memq k keywords)) gf-keywords))
1994            (lose "the method does not accept each of the &KEY arguments~2I~_~
1995                   ~S."
1996                  gf-keywords)))))))
1997
1998(defconstant +sm-specializers-index+
1999  (!bootstrap-slot-index 'standard-method 'specializers))
2000(defconstant +sm-%function-index+
2001  (!bootstrap-slot-index 'standard-method '%function))
2002(defconstant +sm-qualifiers-index+
2003  (!bootstrap-slot-index 'standard-method 'qualifiers))
2004
2005;;; FIXME: we don't actually need this; we could test for the exact
2006;;; class and deal with it as appropriate.  In fact we probably don't
2007;;; need it anyway because we only use this for METHOD-SPECIALIZERS on
2008;;; the standard reader method for METHOD-SPECIALIZERS.  Probably.
2009(dolist (s '(specializers %function))
2010  (aver (= (symbol-value (intern (format nil "+SM-~A-INDEX+" s)))
2011           (!bootstrap-slot-index 'standard-reader-method s)
2012           (!bootstrap-slot-index 'standard-writer-method s)
2013           (!bootstrap-slot-index 'standard-boundp-method s)
2014           (!bootstrap-slot-index 'global-reader-method s)
2015           (!bootstrap-slot-index 'global-writer-method s)
2016           (!bootstrap-slot-index 'global-boundp-method s))))
2017
2018(defvar *standard-method-class-names*
2019  '(standard-method standard-reader-method
2020    standard-writer-method standard-boundp-method
2021    global-reader-method global-writer-method
2022    global-boundp-method))
2023
2024(declaim (list **standard-method-classes**))
2025(defglobal **standard-method-classes** nil)
2026
2027(defun safe-method-specializers (method)
2028  (if (member (class-of method) **standard-method-classes** :test #'eq)
2029      (clos-slots-ref (std-instance-slots method) +sm-specializers-index+)
2030      (method-specializers method)))
2031(defun safe-method-fast-function (method)
2032  (let ((mf (safe-method-function method)))
2033    (and (typep mf '%method-function)
2034         (%method-function-fast-function mf))))
2035(defun safe-method-function (method)
2036  (if (member (class-of method) **standard-method-classes** :test #'eq)
2037      (clos-slots-ref (std-instance-slots method) +sm-%function-index+)
2038      (method-function method)))
2039(defun safe-method-qualifiers (method)
2040  (if (member (class-of method) **standard-method-classes** :test #'eq)
2041      (clos-slots-ref (std-instance-slots method) +sm-qualifiers-index+)
2042      (method-qualifiers method)))
2043
2044(defun set-arg-info1 (gf arg-info new-method methods was-valid-p first-p)
2045  (let* ((existing-p (and methods (cdr methods) new-method))
2046         (nreq (length (arg-info-metatypes arg-info)))
2047         (metatypes (if existing-p
2048                        (arg-info-metatypes arg-info)
2049                        (make-list nreq)))
2050         (type (if existing-p
2051                   (gf-info-simple-accessor-type arg-info)
2052                   nil)))
2053    (when (arg-info-valid-p arg-info)
2054      (dolist (method (if new-method (list new-method) methods))
2055        (let* ((specializers (if (or (eq **boot-state** 'complete)
2056                                     (not (consp method)))
2057                                 (safe-method-specializers method)
2058                                 (early-method-specializers method t)))
2059               (class (if (or (eq **boot-state** 'complete) (not (consp method)))
2060                          (class-of method)
2061                          (early-method-class method)))
2062               (new-type
2063                (when (and class
2064                           (or (not (eq **boot-state** 'complete))
2065                               (eq (generic-function-method-combination gf)
2066                                   *standard-method-combination*)))
2067                  (cond ((or (eq class *the-class-standard-reader-method*)
2068                             (eq class *the-class-global-reader-method*))
2069                         'reader)
2070                        ((or (eq class *the-class-standard-writer-method*)
2071                             (eq class *the-class-global-writer-method*))
2072                         'writer)
2073                        ((or (eq class *the-class-standard-boundp-method*)
2074                             (eq class *the-class-global-boundp-method*))
2075                         'boundp)))))
2076          (setq metatypes (mapcar #'raise-metatype metatypes specializers))
2077          (setq type (cond ((null type) new-type)
2078                           ((eq type new-type) type)
2079                           (t nil)))))
2080      (setf (arg-info-metatypes arg-info) metatypes)
2081      (setf (gf-info-simple-accessor-type arg-info) type)))
2082  (when (or (not was-valid-p) first-p)
2083    (multiple-value-bind (c-a-m-emf std-p)
2084        (if (early-gf-p gf)
2085            (values t t)
2086            (compute-applicable-methods-emf gf))
2087      (setf (gf-info-static-c-a-m-emf arg-info) c-a-m-emf)
2088      (setf (gf-info-c-a-m-emf-std-p arg-info) std-p)
2089      (unless (gf-info-c-a-m-emf-std-p arg-info)
2090        (setf (gf-info-simple-accessor-type arg-info) t))))
2091  (unless was-valid-p
2092    (let ((name (if (eq **boot-state** 'complete)
2093                    (generic-function-name gf)
2094                    (!early-gf-name gf))))
2095      (setf (gf-precompute-dfun-and-emf-p arg-info)
2096            (cond
2097              ((and (consp name)
2098                    (member (car name)
2099                            *internal-pcl-generalized-fun-name-symbols*))
2100                nil)
2101              (t (let* ((symbol (fun-name-block-name name))
2102                        (package (symbol-package symbol)))
2103                   (and (or (eq package *pcl-package*)
2104                            (memq package (package-use-list *pcl-package*)))
2105                        (not (eq package *cl-package*))
2106                        ;; FIXME: this test will eventually be
2107                        ;; superseded by the *internal-pcl...* test,
2108                        ;; above.  While we are in a process of
2109                        ;; transition, however, it should probably
2110                        ;; remain.
2111                        (not (find #\Space (symbol-name symbol))))))))))
2112  (setf (gf-info-fast-mf-p arg-info)
2113        (or (not (eq **boot-state** 'complete))
2114            (let* ((method-class (generic-function-method-class gf))
2115                   (methods (compute-applicable-methods
2116                             #'make-method-lambda
2117                             (list gf (class-prototype method-class)
2118                                   '(lambda) nil))))
2119              (and methods (null (cdr methods))
2120                   (let ((specls (method-specializers (car methods))))
2121                     (and (classp (car specls))
2122                          (eq 'standard-generic-function
2123                              (class-name (car specls)))
2124                          (classp (cadr specls))
2125                          (eq 'standard-method
2126                              (class-name (cadr specls)))))))))
2127  arg-info)
2128
2129;;; This is the early definition of ENSURE-GENERIC-FUNCTION-USING-CLASS.
2130;;;
2131;;; The STATIC-SLOTS field of the funcallable instances used as early
2132;;; generic functions is used to store the early methods and early
2133;;; discriminator code for the early generic function. The static
2134;;; slots field of the fins contains a list whose:
2135;;;    CAR    -   a list of the early methods on this early gf
2136;;;    CADR   -   the early discriminator code for this method
2137(defun ensure-generic-function-using-class (existing spec &rest keys
2138                                            &key (lambda-list nil
2139                                                              lambda-list-p)
2140                                            argument-precedence-order
2141                                            definition-source
2142                                            documentation
2143                                            &allow-other-keys)
2144  (declare (ignore keys))
2145  (cond ((and existing (early-gf-p existing))
2146         (when lambda-list-p
2147           (set-arg-info existing :lambda-list lambda-list))
2148         existing)
2149        ((assoc spec *!generic-function-fixups* :test #'equal)
2150         (if existing
2151             (make-early-gf spec lambda-list lambda-list-p existing
2152                            argument-precedence-order definition-source
2153                            documentation)
2154             (bug "The function ~S is not already defined." spec)))
2155        (existing
2156         (bug "~S should be on the list ~S."
2157              spec '*!generic-function-fixups*))
2158        (t
2159         (pushnew spec *!early-generic-functions* :test #'equal)
2160         (make-early-gf spec lambda-list lambda-list-p nil
2161                        argument-precedence-order definition-source
2162                        documentation))))
2163
2164(defun make-early-gf (spec &optional lambda-list lambda-list-p
2165                      function argument-precedence-order source-location
2166                      documentation)
2167  (let ((fin (allocate-standard-funcallable-instance
2168              *sgf-wrapper* *sgf-slots-init*)))
2169    (set-funcallable-instance-function
2170     fin
2171     (or function
2172         (if (eq spec 'print-object)
2173             #'(lambda (instance stream)
2174                 (print-unreadable-object (instance stream :identity t)
2175                   (format stream "std-instance")))
2176             #'(lambda (&rest args)
2177                 (declare (ignore args))
2178                 (error "The function of the funcallable-instance ~S~
2179                         has not been set." fin)))))
2180    (setf (gdefinition spec) fin)
2181    (!bootstrap-set-slot 'standard-generic-function fin 'name spec)
2182    (!bootstrap-set-slot 'standard-generic-function fin
2183                         'source source-location)
2184    (!bootstrap-set-slot 'standard-generic-function fin
2185                         '%documentation documentation)
2186    (let ((arg-info (make-arg-info)))
2187      (setf (early-gf-arg-info fin) arg-info)
2188      (when lambda-list-p
2189        (setf (info :function :type spec)
2190              (specifier-type
2191               (ftype-declaration-from-lambda-list lambda-list spec))
2192              (info :function :where-from spec) :defined-method)
2193        (if argument-precedence-order
2194            (set-arg-info fin
2195                          :lambda-list lambda-list
2196                          :argument-precedence-order argument-precedence-order)
2197            (set-arg-info fin :lambda-list lambda-list))))
2198    fin))
2199
2200(defun safe-gf-dfun-state (generic-function)
2201  (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2202      (clos-slots-ref (fsc-instance-slots generic-function) +sgf-dfun-state-index+)
2203      (gf-dfun-state generic-function)))
2204(defun (setf safe-gf-dfun-state) (new-value generic-function)
2205  (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2206      (setf (clos-slots-ref (fsc-instance-slots generic-function)
2207                            +sgf-dfun-state-index+)
2208            new-value)
2209      (setf (gf-dfun-state generic-function) new-value)))
2210
2211(defun set-dfun (gf &optional dfun cache info)
2212  (let ((new-state (if (and dfun (or cache info))
2213                       (list* dfun cache info)
2214                       dfun)))
2215    (cond
2216      ((eq **boot-state** 'complete)
2217       ;; Check that we are under the lock.
2218       #+sb-thread
2219       (aver (eq sb-thread:*current-thread* (sb-thread:mutex-owner (gf-lock gf))))
2220       (setf (safe-gf-dfun-state gf) new-state))
2221      (t
2222       (setf (clos-slots-ref (get-slots gf) +sgf-dfun-state-index+)
2223             new-state))))
2224  dfun)
2225
2226(defun gf-dfun-cache (gf)
2227  (let ((state (if (eq **boot-state** 'complete)
2228                   (safe-gf-dfun-state gf)
2229                   (clos-slots-ref (get-slots gf) +sgf-dfun-state-index+))))
2230    (typecase state
2231      (function nil)
2232      (cons (cadr state)))))
2233
2234(defun gf-dfun-info (gf)
2235  (let ((state (if (eq **boot-state** 'complete)
2236                   (safe-gf-dfun-state gf)
2237                   (clos-slots-ref (get-slots gf) +sgf-dfun-state-index+))))
2238    (typecase state
2239      (function nil)
2240      (cons (cddr state)))))
2241
2242(defconstant +sgf-name-index+
2243  (!bootstrap-slot-index 'standard-generic-function 'name))
2244
2245(defun !early-gf-name (gf)
2246  (clos-slots-ref (get-slots gf) +sgf-name-index+))
2247
2248(defun gf-lambda-list (gf)
2249  (let ((arg-info (if (eq **boot-state** 'complete)
2250                      (gf-arg-info gf)
2251                      (early-gf-arg-info gf))))
2252    (if (eq :no-lambda-list (arg-info-lambda-list arg-info))
2253        (let ((methods (if (eq **boot-state** 'complete)
2254                           (generic-function-methods gf)
2255                           (early-gf-methods gf))))
2256          (if (null methods)
2257              (progn
2258                (warn "no way to determine the lambda list for ~S" gf)
2259                nil)
2260              (let* ((method (car (last methods)))
2261                     (ll (if (consp method)
2262                             (early-method-lambda-list method)
2263                             (method-lambda-list method))))
2264                (create-gf-lambda-list ll))))
2265        (arg-info-lambda-list arg-info))))
2266
2267(defmacro real-ensure-gf-internal (gf-class all-keys env)
2268  `(progn
2269     (cond ((symbolp ,gf-class)
2270            (setq ,gf-class (find-class ,gf-class t ,env)))
2271           ((classp ,gf-class))
2272           (t
2273            (error "The :GENERIC-FUNCTION-CLASS argument (~S) was neither a~%~
2274                    class nor a symbol that names a class."
2275                   ,gf-class)))
2276     (unless (class-finalized-p ,gf-class)
2277       (if (class-has-a-forward-referenced-superclass-p ,gf-class)
2278           ;; FIXME: reference MOP documentation -- this is an
2279           ;; additional requirement on our users
2280           (error "The generic function class ~S is not finalizeable" ,gf-class)
2281           (finalize-inheritance ,gf-class)))
2282     (remf ,all-keys :generic-function-class)
2283     (remf ,all-keys :environment)
2284     (let ((combin (getf ,all-keys :method-combination)))
2285       (etypecase combin
2286         (cons
2287          (setf (getf ,all-keys :method-combination)
2288                (find-method-combination (class-prototype ,gf-class)
2289                                         (car combin)
2290                                         (cdr combin))))
2291         ((or null method-combination))))
2292    (let ((method-class (getf ,all-keys :method-class '.shes-not-there.)))
2293      (unless (eq method-class '.shes-not-there.)
2294        (setf (getf ,all-keys :method-class)
2295              (cond ((classp method-class)
2296                     method-class)
2297                    (t (find-class method-class t ,env))))))))
2298
2299(defun note-gf-signature (fun-name lambda-list-p lambda-list)
2300  (unless lambda-list-p
2301    ;; Use the existing lambda-list, if any. It is reasonable to do eg.
2302    ;;
2303    ;;   (if (fboundp name)
2304    ;;       (ensure-generic-function name)
2305    ;;       (ensure-generic-function name :lambda-list '(foo)))
2306    ;;
2307    ;; in which case we end up here with no lambda-list in the first leg.
2308    (setf (values lambda-list lambda-list-p)
2309          (handler-case
2310              (values (generic-function-lambda-list (fdefinition fun-name))
2311                      t)
2312            ((or warning error) ()
2313              (values nil nil)))))
2314  (let ((gf-type
2315         (specifier-type
2316          (if lambda-list-p
2317              (ftype-declaration-from-lambda-list lambda-list fun-name)
2318              'function)))
2319        (old-type nil))
2320    ;; FIXME: Ideally we would like to not clobber it, but because generic
2321    ;; functions assert their FTYPEs callers believing the FTYPE are left with
2322    ;; unsafe assumptions. Hence the clobbering. Be quiet when the new type
2323    ;; is a subtype of the old one, though -- even though the type is not
2324    ;; trusted anymore, the warning is still not quite as interesting.
2325    (when (and (eq :declared (info :function :where-from fun-name))
2326               (not (csubtypep gf-type (setf old-type (proclaimed-ftype fun-name)))))
2327      (style-warn "~@<Generic function ~S clobbers an earlier ~S proclamation ~S ~
2328                   for the same name with ~S.~:@>"
2329                  fun-name 'ftype
2330                  (type-specifier old-type)
2331                  (type-specifier gf-type)))
2332    (setf (info :function :type fun-name) gf-type
2333          (info :function :where-from fun-name) :defined-method)
2334    fun-name))
2335
2336(defun real-ensure-gf-using-class--generic-function
2337       (existing
2338        fun-name
2339        &rest all-keys
2340        &key environment (lambda-list nil lambda-list-p)
2341        (generic-function-class 'standard-generic-function)
2342        &allow-other-keys)
2343  (real-ensure-gf-internal generic-function-class all-keys environment)
2344  ;; KLUDGE: the above macro does SETQ on GENERIC-FUNCTION-CLASS,
2345  ;; which is what makes the next line work
2346  (unless (eq (class-of existing) generic-function-class)
2347    (change-class existing generic-function-class))
2348  (prog1
2349      (apply #'reinitialize-instance existing all-keys)
2350    (note-gf-signature fun-name lambda-list-p lambda-list)))
2351
2352(defun real-ensure-gf-using-class--null
2353       (existing
2354        fun-name
2355        &rest all-keys
2356        &key environment (lambda-list nil lambda-list-p)
2357             (generic-function-class 'standard-generic-function)
2358        &allow-other-keys)
2359  (declare (ignore existing))
2360  (real-ensure-gf-internal generic-function-class all-keys environment)
2361  (prog1
2362      (setf (gdefinition fun-name)
2363            (apply #'make-instance generic-function-class
2364                   :name fun-name all-keys))
2365    (note-gf-signature fun-name lambda-list-p lambda-list)))
2366
2367(defun safe-gf-arg-info (generic-function)
2368  (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2369      (clos-slots-ref (fsc-instance-slots generic-function)
2370                      +sgf-arg-info-index+)
2371      (gf-arg-info generic-function)))
2372
2373;;; FIXME: this function took on a slightly greater role than it
2374;;; previously had around 2005-11-02, when CSR fixed the bug whereby
2375;;; having more than one subclass of standard-generic-function caused
2376;;; the whole system to die horribly through a metacircle in
2377;;; GF-ARG-INFO.  The fix is to be slightly more disciplined about
2378;;; calling accessor methods -- we call GET-GENERIC-FUN-INFO when
2379;;; computing discriminating functions, so we need to be careful about
2380;;; having a base case for the recursion, and we provide that with the
2381;;; STANDARD-GENERIC-FUNCTION case below.  However, we are not (yet)
2382;;; as disciplined as CLISP's CLOS/MOP, and it would be nice to get to
2383;;; that stage, where all potentially dangerous cases are enumerated
2384;;; and stopped.  -- CSR, 2005-11-02.
2385(defun get-generic-fun-info (gf)
2386  ;; values   nreq applyp metatypes nkeys arg-info
2387  (multiple-value-bind (applyp metatypes arg-info)
2388      (let* ((arg-info (if (early-gf-p gf)
2389                           (early-gf-arg-info gf)
2390                           (safe-gf-arg-info gf)))
2391             (metatypes (arg-info-metatypes arg-info)))
2392        (values (arg-info-applyp arg-info)
2393                metatypes
2394                arg-info))
2395    (let ((nreq 0)
2396          (nkeys 0))
2397      (declare (fixnum nreq nkeys))
2398      (dolist (x metatypes)
2399        (incf nreq)
2400        (unless (eq x t)
2401          (incf nkeys)))
2402      (values nreq applyp metatypes
2403              nkeys
2404              arg-info))))
2405
2406(defun generic-function-nreq (gf)
2407  (let* ((arg-info (if (early-gf-p gf)
2408                       (early-gf-arg-info gf)
2409                       (safe-gf-arg-info gf)))
2410         (metatypes (arg-info-metatypes arg-info)))
2411    (declare (list metatypes))
2412    (length metatypes)))
2413
2414(defun !early-make-a-method (class qualifiers arglist specializers initargs doc
2415                            &key slot-name object-class method-class-function
2416                            definition-source)
2417  (aver (notany #'sb-pcl::eql-specializer-p specializers))
2418  (binding*
2419      ;; Figure out whether we got class objects or class names as the
2420      ;; specializers and set parsed and unparsed appropriately. If we
2421      ;; got class objects, then we can compute unparsed, but if we
2422      ;; got class names we don't try to compute parsed.
2423      (((parsed unparsed)
2424        (if (every #'classp specializers)
2425            (values specializers
2426                    (mapcar (lambda (s)
2427                              (if (eq s t) t (class-name s)))
2428                            specializers))
2429            (values () specializers)))
2430       (result
2431        (list :early-method
2432
2433              (getf initargs :function)
2434              (let ((mf (getf initargs :function)))
2435                (aver mf)
2436                (and (typep mf '%method-function)
2437                     (%method-function-fast-function mf)))
2438
2439              ;; the parsed specializers. This is used by
2440              ;; EARLY-METHOD-SPECIALIZERS to cache the parse.
2441              ;; Note that this only comes into play when there is
2442              ;; more than one early method on an early gf.
2443              parsed
2444
2445              ;; A list to which REAL-MAKE-A-METHOD can be applied
2446              ;; to make a real method corresponding to this early
2447              ;; one.
2448              (append
2449               (list class qualifiers arglist unparsed
2450                     initargs doc)
2451               (when slot-name
2452                 (list :slot-name slot-name :object-class object-class
2453                       :method-class-function method-class-function))
2454               (list :definition-source definition-source)))))
2455    (initialize-method-function initargs result)
2456    result))
2457
2458(defun real-make-a-method
2459       (class qualifiers lambda-list specializers initargs doc
2460        &rest args &key slot-name object-class method-class-function
2461        definition-source)
2462  (if method-class-function
2463      (let* ((object-class (if (classp object-class) object-class
2464                               (find-class object-class)))
2465             (slots (class-direct-slots object-class))
2466             (slot-definition (find slot-name slots
2467                                    :key #'slot-definition-name)))
2468        (aver slot-name)
2469        (aver slot-definition)
2470        (let ((initargs (list* :qualifiers qualifiers :lambda-list lambda-list
2471                               :specializers specializers :documentation doc
2472                               :slot-definition slot-definition
2473                               :slot-name slot-name initargs)))
2474          (apply #'make-instance
2475                 (apply method-class-function object-class slot-definition
2476                        initargs)
2477                 :definition-source definition-source
2478                 initargs)))
2479      (apply #'make-instance class :qualifiers qualifiers
2480             :lambda-list lambda-list :specializers specializers
2481             :documentation doc (append args initargs))))
2482
2483(defun early-method-function (early-method)
2484  (values (cadr early-method) (caddr early-method)))
2485
2486(defun early-method-class (early-method)
2487  (find-class (car (fifth early-method))))
2488
2489(defun early-method-standard-accessor-p (early-method)
2490  (let ((class (first (fifth early-method))))
2491    (or (eq class 'standard-reader-method)
2492        (eq class 'standard-writer-method)
2493        (eq class 'standard-boundp-method))))
2494
2495(defun early-method-standard-accessor-slot-name (early-method)
2496  (eighth (fifth early-method)))
2497
2498;;; Fetch the specializers of an early method. This is basically just
2499;;; a simple accessor except that when the second argument is t, this
2500;;; converts the specializers from symbols into class objects. The
2501;;; class objects are cached in the early method, this makes
2502;;; bootstrapping faster because the class objects only have to be
2503;;; computed once.
2504;;;
2505;;; NOTE:
2506;;;  The second argument should only be passed as T by
2507;;;  early-lookup-method. This is to implement the rule that only when
2508;;;  there is more than one early method on a generic function is the
2509;;;  conversion from class names to class objects done. This
2510;;;  corresponds to the fact that we are only allowed to have one
2511;;;  method on any generic function up until the time classes exist.
2512(defun early-method-specializers (early-method &optional objectsp)
2513  (if (and (listp early-method)
2514           (eq (car early-method) :early-method))
2515      (cond ((eq objectsp t)
2516             (or (fourth early-method)
2517                 (setf (fourth early-method)
2518                       (mapcar #'find-class (cadddr (fifth early-method))))))
2519            (t
2520             (fourth (fifth early-method))))
2521      (error "~S is not an early-method." early-method)))
2522
2523(defun early-method-qualifiers (early-method)
2524  (second (fifth early-method)))
2525
2526(defun early-method-lambda-list (early-method)
2527  (third (fifth early-method)))
2528
2529(defun early-method-initargs (early-method)
2530  (fifth (fifth early-method)))
2531
2532(defun (setf early-method-initargs) (new-value early-method)
2533  (setf (fifth (fifth early-method)) new-value))
2534
2535(defun !early-add-named-method (generic-function-name qualifiers
2536                               specializers arglist &rest initargs
2537                               &key documentation definition-source
2538                               &allow-other-keys)
2539  (let* (;; we don't need to deal with the :generic-function-class
2540         ;; argument here because the default,
2541         ;; STANDARD-GENERIC-FUNCTION, is right for all early generic
2542         ;; functions.  (See REAL-ADD-NAMED-METHOD)
2543         (gf (ensure-generic-function generic-function-name))
2544         (existing
2545           (dolist (m (early-gf-methods gf))
2546             (when (and (equal (early-method-specializers m) specializers)
2547                        (equal (early-method-qualifiers m) qualifiers))
2548               (return m)))))
2549    (setf (getf (getf initargs 'plist) :name)
2550          (make-method-spec gf qualifiers specializers))
2551    (let ((new (make-a-method 'standard-method qualifiers arglist
2552                              specializers initargs documentation
2553                              :definition-source definition-source)))
2554      (when existing (remove-method gf existing))
2555      (add-method gf new))))
2556
2557;;; This is the early version of ADD-METHOD. Later this will become a
2558;;; generic function. See !FIX-EARLY-GENERIC-FUNCTIONS which has
2559;;; special knowledge about ADD-METHOD.
2560(defun add-method (generic-function method)
2561  (when (not (fsc-instance-p generic-function))
2562    (error "Early ADD-METHOD didn't get a funcallable instance."))
2563  (when (not (and (listp method) (eq (car method) :early-method)))
2564    (error "Early ADD-METHOD didn't get an early method."))
2565  (push method (early-gf-methods generic-function))
2566  (set-arg-info generic-function :new-method method)
2567  (unless (assoc (!early-gf-name generic-function)
2568                 *!generic-function-fixups*
2569                 :test #'equal)
2570    (update-dfun generic-function)))
2571
2572;;; This is the early version of REMOVE-METHOD. See comments on
2573;;; the early version of ADD-METHOD.
2574(defun remove-method (generic-function method)
2575  (when (not (fsc-instance-p generic-function))
2576    (error "An early remove-method didn't get a funcallable instance."))
2577  (when (not (and (listp method) (eq (car method) :early-method)))
2578    (error "An early remove-method didn't get an early method."))
2579  (setf (early-gf-methods generic-function)
2580        (remove method (early-gf-methods generic-function)))
2581  (set-arg-info generic-function)
2582  (unless (assoc (!early-gf-name generic-function)
2583                 *!generic-function-fixups*
2584                 :test #'equal)
2585    (update-dfun generic-function)))
2586
2587;;; This is the early version of GET-METHOD. See comments on the early
2588;;; version of ADD-METHOD.
2589(defun get-method (generic-function qualifiers specializers
2590                                    &optional (errorp t))
2591  (if (early-gf-p generic-function)
2592      (or (dolist (m (early-gf-methods generic-function))
2593            (when (and (or (equal (early-method-specializers m nil)
2594                                  specializers)
2595                           (equal (early-method-specializers m t)
2596                                  specializers))
2597                       (equal (early-method-qualifiers m) qualifiers))
2598              (return m)))
2599          (if errorp
2600              (error "can't get early method")
2601              nil))
2602      (real-get-method generic-function qualifiers specializers errorp)))
2603
2604;; minor KLUDGE: a separate code component for this function allows GCing
2605;; a few symbols and their associated code that would otherwise be retained:
2606;;  *!EARLY-{GENERIC-}FUNCTIONS*, *!GENERIC-FUNCTION-FIXUPS*
2607(defun early-gf-primary-slow-method-fn (fn)
2608  (lambda (args next-methods)
2609    (declare (ignore next-methods))
2610    (apply fn args)))
2611
2612(defun !fix-early-generic-functions ()
2613  (let ((accessors nil))
2614    ;; Rearrange *!EARLY-GENERIC-FUNCTIONS* to speed up
2615    ;; FIX-EARLY-GENERIC-FUNCTIONS.
2616    (dolist (early-gf-spec *!early-generic-functions*)
2617      (when (every #'early-method-standard-accessor-p
2618                   (early-gf-methods (gdefinition early-gf-spec)))
2619        (push early-gf-spec accessors)))
2620    (dolist (spec (nconc accessors
2621                         '(accessor-method-slot-name
2622                           generic-function-methods
2623                           method-specializers
2624                           specializer-type
2625                           specializer-class
2626                           slot-definition-location
2627                           slot-definition-name
2628                           class-slots
2629                           gf-arg-info
2630                           class-precedence-list
2631                           slot-boundp-using-class
2632                           (setf slot-value-using-class)
2633                           slot-value-using-class)))
2634      (/show spec)
2635      (setq *!early-generic-functions*
2636            (cons spec
2637                  (delete spec *!early-generic-functions* :test #'equal))))
2638
2639    (dolist (early-gf-spec *!early-generic-functions*)
2640      (/show early-gf-spec)
2641      (let* ((gf (gdefinition early-gf-spec))
2642             (methods (mapcar (lambda (early-method)
2643                                (let ((args (copy-list (fifth
2644                                                        early-method))))
2645                                  (setf (fourth args)
2646                                        (early-method-specializers
2647                                         early-method t))
2648                                  (apply #'real-make-a-method args)))
2649                              (early-gf-methods gf))))
2650        (setf (generic-function-method-class gf) *the-class-standard-method*)
2651        (setf (generic-function-method-combination gf)
2652              *standard-method-combination*)
2653        (set-methods gf methods)))
2654
2655    (dolist (fn *!early-functions*)
2656      (/show fn)
2657      (setf (gdefinition (car fn)) (fdefinition (caddr fn))))
2658
2659    (loop for (fspec method-combination . methods) in *!generic-function-fixups*
2660       for gf = (gdefinition fspec) do
2661       (flet ((make-method (spec)
2662                (destructuring-bind
2663                      (lambda-list specializers qualifiers fun-name) spec
2664                  (let* ((specializers (mapcar #'find-class specializers))
2665                         (fun-name (or fun-name fspec))
2666                         (fun (fdefinition fun-name))
2667                         (initargs (list :function
2668                                         (set-fun-name
2669                                          (early-gf-primary-slow-method-fn fun)
2670                                          `(call ,fun-name)))))
2671                    (declare (type function fun))
2672                    (make-a-method
2673                     'standard-method
2674                     qualifiers lambda-list specializers initargs nil)))))
2675         (setf (generic-function-method-class gf)
2676               *the-class-standard-method*
2677               (generic-function-method-combination gf)
2678               (ecase method-combination
2679                 (standard *standard-method-combination*)
2680                 (or *or-method-combination*)))
2681         (set-methods gf (mapcar #'make-method methods)))))
2682
2683  (/show "leaving !FIX-EARLY-GENERIC-FUNCTIONS"))
2684
2685;;; PARSE-DEFMETHOD is used by DEFMETHOD to parse the &REST argument
2686;;; into the 'real' arguments. This is where the syntax of DEFMETHOD
2687;;; is really implemented.
2688(defun parse-defmethod (cdr-of-form)
2689  (declare (list cdr-of-form))
2690  (let ((qualifiers ())
2691        (spec-ll ()))
2692    (loop (if (and (car cdr-of-form) (atom (car cdr-of-form)))
2693              (push (pop cdr-of-form) qualifiers)
2694              (return (setq qualifiers (nreverse qualifiers)))))
2695    (setq spec-ll (pop cdr-of-form))
2696    (values qualifiers spec-ll cdr-of-form)))
2697
2698(defun parse-specializers (generic-function specializers)
2699  (declare (list specializers))
2700  (flet ((parse (spec)
2701           (parse-specializer-using-class generic-function spec)))
2702    (mapcar #'parse specializers)))
2703
2704(defun unparse-specializers (generic-function specializers)
2705  (declare (list specializers))
2706  (flet ((unparse (spec)
2707           (unparse-specializer-using-class generic-function spec)))
2708    (mapcar #'unparse specializers)))
2709
2710(macrolet ((def (n name)
2711             `(defun ,name (lambda-list)
2712                (nth-value ,n (parse-specialized-lambda-list lambda-list)))))
2713  ;; We don't need these, but according to the unit tests,
2714  ;; they're mandated by AMOP.
2715  (def 1 extract-lambda-list)
2716  (def 2 extract-specializer-names))
2717
2718(define-condition specialized-lambda-list-error
2719    (reference-condition simple-program-error)
2720  ()
2721  (:default-initargs :references (list '(:ansi-cl :section (3 4 3)))))
2722
2723;; Return 3 values:
2724;; - the bound variables, without defaults, supplied-p vars, or &AUX vars.
2725;; - the lambda list without specializers.
2726;; - just the specializers
2727(defun parse-specialized-lambda-list (arglist)
2728  (multiple-value-bind (llks specialized optional rest key aux)
2729      (parse-lambda-list
2730       arglist
2731       :context 'defmethod
2732       :accept (lambda-list-keyword-mask
2733                '(&optional &rest &key &allow-other-keys &aux))
2734       :silent t ; never signal &OPTIONAL + &KEY style-warning
2735       :condition-class 'specialized-lambda-list-error)
2736    (let ((required (mapcar (lambda (x) (if (listp x) (car x) x)) specialized)))
2737      (values (append required
2738                      (mapcar #'parse-optional-arg-spec optional)
2739                      rest
2740                      ;; Preserve keyword-names when given as (:KEYWORD var)
2741                      (mapcar (lambda (x) (if (typep x '(cons cons))
2742                                              (car x)
2743                                              (parse-key-arg-spec x))) key))
2744              (make-lambda-list llks nil required optional rest key aux)
2745              (mapcar (lambda (x) (if (listp x) (cadr x) t)) specialized)))))
2746
2747(setq **boot-state** 'early)
2748
2749;;; FIXME: In here there was a #-CMU definition of SYMBOL-MACROLET
2750;;; which used %WALKER stuff. That suggests to me that maybe the code
2751;;; walker stuff was only used for implementing stuff like that; maybe
2752;;; it's not needed any more? Hunt down what it was used for and see.
2753
2754(defun extract-the (form)
2755  (cond ((and (consp form) (eq (car form) 'the))
2756         (aver (proper-list-of-length-p form 3))
2757         (third form))
2758        (t
2759         form)))
2760
2761(defmacro with-slots (slots instance &body body)
2762  (let ((in (gensym)))
2763    `(let ((,in ,instance))
2764       (declare (ignorable ,in))
2765       ,@(let ((instance (extract-the instance)))
2766           (and (symbolp instance)
2767                `((declare (%variable-rebinding ,in ,instance)))))
2768       ,in
2769       (symbol-macrolet ,(mapcar (lambda (slot-entry)
2770                                   (let ((var-name
2771                                          (if (symbolp slot-entry)
2772                                              slot-entry
2773                                              (car slot-entry)))
2774                                         (slot-name
2775                                          (if (symbolp slot-entry)
2776                                              slot-entry
2777                                              (cadr slot-entry))))
2778                                     `(,var-name
2779                                       (slot-value ,in ',slot-name))))
2780                                 slots)
2781                        ,@body))))
2782
2783(defmacro with-accessors (slots instance &body body)
2784  (let ((in (gensym)))
2785    `(let ((,in ,instance))
2786       (declare (ignorable ,in))
2787       ,@(let ((instance (extract-the instance)))
2788           (and (symbolp instance)
2789                `((declare (%variable-rebinding ,in ,instance)))))
2790       ,in
2791       (symbol-macrolet ,(mapcar (lambda (slot-entry)
2792                                   (let ((var-name (car slot-entry))
2793                                         (accessor-name (cadr slot-entry)))
2794                                     `(,var-name (,accessor-name ,in))))
2795                                 slots)
2796          ,@body))))
2797