src/pcl/boot.lisp

   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 \f
  26 #|
  27
  28 The CommonLoops evaluator is meta-circular.
  29
  30 Most of the code in PCL is methods on generic functions, including
  31 most of the code that actually implements generic functions and method
  32 lookup.
  33
  34 So, we have a classic bootstrapping problem. The solution to this is
  35 to first get a cheap implementation of generic functions running,
  36 these are called early generic functions. These early generic
  37 functions and the corresponding early methods and early method lookup
  38 are used to get enough of the system running that it is possible to
  39 create real generic functions and methods and implement real method
  40 lookup. At that point (done in the file FIXUP) the function
  41 !FIX-EARLY-GENERIC-FUNCTIONS is called to convert all the early generic
  42 functions to real generic functions.
  43
  44 The cheap generic functions are built using the same
  45 FUNCALLABLE-INSTANCE objects that real generic functions are made out of.
  46 This means that as PCL is being bootstrapped, the cheap generic
  47 function objects which are being created are the same objects which
  48 will 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
  54 This file defines the DEFMETHOD macro and the mechanism used to expand
  55 it. This includes the mechanism for processing the body of a method.
  56 DEFMETHOD basically expands into a call to LOAD-DEFMETHOD, which
  57 basically calls ADD-METHOD to add the method to the generic function.
  58 These expansions can be loaded either during bootstrapping or when PCL
  59 is fully up and running.
  60
  61 An important effect of this arrangement is it means we can compile
  62 files with DEFMETHOD forms in them in a completely running PCL, but
  63 then load those files back in during bootstrapping. This makes
  64 development easier. It also means there is only one set of code for
  65 processing DEFMETHOD. Bootstrapping works by being sure to have
  66 LOAD-METHOD be careful to call only primitives which work during
  67 bootstrapping.
  68
  69 |#
  70
  71 ;;; FIXME: As of sbcl-0.6.9.10, PCL still uses this nonstandard type
  72 ;;; of declaration internally. It would be good to figure out how to
  73 ;;; get rid of it, or failing that, (1) document why it's needed and
  74 ;;; (2) use a private symbol with a forbidding name which suggests
  75 ;;; it's not to be messed with by the user (e.g. SB-PCL:%CLASS)
  76 ;;; instead of the too-inviting CLASS. (I tried just deleting the
  77 ;;; declarations in MAKE-METHOD-LAMBDA-INTERNAL ca. sbcl-0.6.9.10, but
  78 ;;; then things break.)
  79 (declaim (declaration class))
  80
  81 (declaim (notinline make-a-method
  82                     add-named-method
  83                     ensure-generic-function-using-class
  84                     add-method
  85                     remove-method))
  86
  87 (defvar *!early-functions*
  88         '((make-a-method early-make-a-method
  89                          real-make-a-method)
  90           (add-named-method early-add-named-method
  91                             real-add-named-method)
  92           ))
  93
  94 ;;; For each of the early functions, arrange to have it point to its
  95 ;;; early definition. Do this in a way that makes sure that if we
  96 ;;; redefine one of the early definitions the redefinition will take
  97 ;;; effect. This makes development easier.
  98 (dolist (fns *!early-functions*)
  99   (let ((name (car fns))
 100         (early-name (cadr fns)))
 101     (setf (gdefinition name)
 102             (set-fun-name
 103              (lambda (&rest args)
 104                (apply (fdefinition early-name) args))
 105              name))))
 106
 107 ;;; *!GENERIC-FUNCTION-FIXUPS* is used by !FIX-EARLY-GENERIC-FUNCTIONS
 108 ;;; to convert the few functions in the bootstrap which are supposed
 109 ;;; to be generic functions but can't be early on.
 110 (defvar *!generic-function-fixups*
 111   '((add-method
 112      ((generic-function method)  ;lambda-list
 113       (standard-generic-function method) ;specializers
 114       real-add-method))          ;method-function
 115     (remove-method
 116      ((generic-function method)
 117       (standard-generic-function method)
 118       real-remove-method))
 119     (get-method
 120      ((generic-function qualifiers specializers &optional (errorp t))
 121       (standard-generic-function t t)
 122       real-get-method))
 123     (ensure-generic-function-using-class
 124      ((generic-function fun-name
 125                         &key generic-function-class environment
 126                         &allow-other-keys)
 127       (generic-function t)
 128       real-ensure-gf-using-class--generic-function)
 129      ((generic-function fun-name
 130                         &key generic-function-class environment
 131                         &allow-other-keys)
 132       (null t)
 133       real-ensure-gf-using-class--null))
 134     (make-method-lambda
 135      ((proto-generic-function proto-method lambda-expression environment)
 136       (standard-generic-function standard-method t t)
 137       real-make-method-lambda))
 138     (make-method-initargs-form
 139      ((proto-generic-function proto-method
 140                               lambda-expression
 141                               lambda-list environment)
 142       (standard-generic-function standard-method t t t)
 143       real-make-method-initargs-form))
 144     (compute-effective-method
 145      ((generic-function combin applicable-methods)
 146       (generic-function standard-method-combination t)
 147       standard-compute-effective-method))))
 148 \f
 149 (defmacro defgeneric (fun-name lambda-list &body options)
 150   (declare (type list lambda-list))
 151   (unless (legal-fun-name-p fun-name)
 152     (error 'simple-program-error
 153            :format-control "illegal generic function name ~S"
 154            :format-arguments (list fun-name)))
 155   (check-gf-lambda-list lambda-list)
 156   (let ((initargs ())
 157         (methods ()))
 158     (flet ((duplicate-option (name)
 159              (error 'simple-program-error
 160                     :format-control "The option ~S appears more than once."
 161                     :format-arguments (list name)))
 162            (expand-method-definition (qab) ; QAB = qualifiers, arglist, body
 163              (let* ((arglist-pos (position-if #'listp qab))
 164                     (arglist (elt qab arglist-pos))
 165                     (qualifiers (subseq qab 0 arglist-pos))
 166                     (body (nthcdr (1+ arglist-pos) qab)))
 167                `(push (defmethod ,fun-name ,@qualifiers ,arglist ,@body)
 168                       (generic-function-initial-methods #',fun-name)))))
 169       (macrolet ((initarg (key) `(getf initargs ,key)))
 170         (dolist (option options)
 171           (let ((car-option (car option)))
 172             (case car-option
 173               (declare
 174                (when (and
 175                       (consp (cadr option))
 176                       (member (first (cadr option))
 177                               ;; FIXME: this list is slightly weird.
 178                               ;; ANSI (on the DEFGENERIC page) in one
 179                               ;; place allows only OPTIMIZE; in
 180                               ;; another place gives this list of
 181                               ;; disallowed declaration specifiers.
 182                               ;; This seems to be the only place where
 183                               ;; the FUNCTION declaration is
 184                               ;; mentioned; TYPE seems to be missing.
 185                               ;; Very strange.  -- CSR, 2002-10-21
 186                               '(declaration ftype function
 187                                 inline notinline special)))
 188                  (error 'simple-program-error
 189                         :format-control "The declaration specifier ~S ~
 190                                          is not allowed inside DEFGENERIC."
 191                         :format-arguments (list (cadr option))))
 192                (push (cadr option) (initarg :declarations)))
 193               (:method-combination
 194                (when (initarg car-option)
 195                  (duplicate-option car-option))
 196                (unless (symbolp (cadr option))
 197                  (error 'simple-program-error
 198                         :format-control "METHOD-COMBINATION name not a ~
 199                                          symbol: ~S"
 200                         :format-arguments (list (cadr option))))
 201                (setf (initarg car-option)
 202                      `',(cdr option)))
 203               (:argument-precedence-order
 204                (let* ((required (parse-lambda-list lambda-list))
 205                       (supplied (cdr option)))
 206                  (unless (= (length required) (length supplied))
 207                    (error 'simple-program-error
 208                           :format-control "argument count discrepancy in ~
 209                                            :ARGUMENT-PRECEDENCE-ORDER clause."
 210                           :format-arguments nil))
 211                  (when (set-difference required supplied)
 212                    (error 'simple-program-error
 213                           :format-control "unequal sets for ~
 214                                            :ARGUMENT-PRECEDENCE-ORDER clause: ~
 215                                            ~S and ~S"
 216                           :format-arguments (list required supplied)))
 217                  (setf (initarg car-option)
 218                        `',(cdr option))))
 219               ((:documentation :generic-function-class :method-class)
 220                (unless (proper-list-of-length-p option 2)
 221                  (error "bad list length for ~S" option))
 222                (if (initarg car-option)
 223                    (duplicate-option car-option)
 224                    (setf (initarg car-option) `',(cadr option))))
 225               (:method
 226                (push (cdr option) methods))
 227               (t
 228                ;; ANSI requires that unsupported things must get a
 229                ;; PROGRAM-ERROR.
 230                (error 'simple-program-error
 231                       :format-control "unsupported option ~S"
 232                       :format-arguments (list option))))))
 233
 234         (when (initarg :declarations)
 235           (setf (initarg :declarations)
 236                 `',(initarg :declarations))))
 237       `(progn
 238          (eval-when (:compile-toplevel :load-toplevel :execute)
 239            (compile-or-load-defgeneric ',fun-name))
 240          (load-defgeneric ',fun-name ',lambda-list ,@initargs)
 241         ,@(mapcar #'expand-method-definition methods)
 242          #',fun-name))))
 243
 244 (defun compile-or-load-defgeneric (fun-name)
 245   (proclaim-as-fun-name fun-name)
 246   (note-name-defined fun-name :function)
 247   (unless (eq (info :function :where-from fun-name) :declared)
 248     (setf (info :function :where-from fun-name) :defined)
 249     (setf (info :function :type fun-name)
 250           (specifier-type 'function))))
 251
 252 (defun load-defgeneric (fun-name lambda-list &rest initargs)
 253   (when (fboundp fun-name)
 254     (style-warn "redefining ~S in DEFGENERIC" fun-name)
 255     (let ((fun (fdefinition fun-name)))
 256       (when (generic-function-p fun)
 257         (loop for method in (generic-function-initial-methods fun)
 258               do (remove-method fun method))
 259         (setf (generic-function-initial-methods fun) '()))))
 260   (apply #'ensure-generic-function
 261          fun-name
 262          :lambda-list lambda-list
 263          :definition-source `((defgeneric ,fun-name) ,*load-pathname*)
 264          initargs))
 265
 266 ;;; As per section 3.4.2 of the ANSI spec, generic function lambda
 267 ;;; lists have some special limitations, which we check here.
 268 (defun check-gf-lambda-list (lambda-list)
 269   (flet ((ensure (arg ok)
 270            (unless ok
 271              (error
 272               ;; (s/invalid/non-ANSI-conforming/ because the old PCL
 273               ;; implementation allowed this, so people got used to
 274               ;; it, and maybe this phrasing will help them to guess
 275               ;; why their program which worked under PCL no longer works.)
 276               "~@<non-ANSI-conforming argument ~S ~_in the generic function lambda list ~S~:>"
 277               arg lambda-list))))
 278     (multiple-value-bind (required optional restp rest keyp keys allowp
 279                           auxp aux morep more-context more-count)
 280         (parse-lambda-list lambda-list)
 281       (declare (ignore required)) ; since they're no different in a gf ll
 282       (declare (ignore restp rest)) ; since they're no different in a gf ll
 283       (declare (ignore allowp)) ; since &ALLOW-OTHER-KEYS is fine either way
 284       (declare (ignore aux)) ; since we require AUXP=NIL
 285       (declare (ignore more-context more-count)) ; safely ignored unless MOREP
 286       ;; no defaults allowed for &OPTIONAL arguments
 287       (dolist (i optional)
 288         (ensure i (or (symbolp i)
 289                       (and (consp i) (symbolp (car i)) (null (cdr i))))))
 290       ;; no defaults allowed for &KEY arguments
 291       (when keyp
 292         (dolist (i keys)
 293           (ensure i (or (symbolp i)
 294                         (and (consp i)
 295                              (or (symbolp (car i))
 296                                  (and (consp (car i))
 297                                       (symbolp (caar i))
 298                                       (symbolp (cadar i))
 299                                       (null (cddar i))))
 300                              (null (cdr i)))))))
 301       ;; no &AUX allowed
 302       (when auxp
 303         (error "&AUX is not allowed in a generic function lambda list: ~S"
 304                lambda-list))
 305       ;; Oh, *puhlease*... not specifically as per section 3.4.2 of
 306       ;; the ANSI spec, but the CMU CL &MORE extension does not
 307       ;; belong here!
 308       (aver (not morep)))))
 309 \f
 310 (defmacro defmethod (&rest args &environment env)
 311   (multiple-value-bind (name qualifiers lambda-list body)
 312       (parse-defmethod args)
 313     (multiple-value-bind (proto-gf proto-method)
 314         (prototypes-for-make-method-lambda name)
 315       (expand-defmethod name
 316                         proto-gf
 317                         proto-method
 318                         qualifiers
 319                         lambda-list
 320                         body
 321                         env))))
 322
 323 (defun prototypes-for-make-method-lambda (name)
 324   (if (not (eq *boot-state* 'complete))
 325       (values nil nil)
 326       (let ((gf? (and (gboundp name)
 327                       (gdefinition name))))
 328         (if (or (null gf?)
 329                 (not (generic-function-p gf?)))
 330             (values (class-prototype (find-class 'standard-generic-function))
 331                     (class-prototype (find-class 'standard-method)))
 332             (values gf?
 333                     (class-prototype (or (generic-function-method-class gf?)
 334                                          (find-class 'standard-method))))))))
 335
 336 ;;; Take a name which is either a generic function name or a list specifying
 337 ;;; a SETF generic function (like: (SETF <generic-function-name>)). Return
 338 ;;; the prototype instance of the method-class for that generic function.
 339 ;;;
 340 ;;; If there is no generic function by that name, this returns the
 341 ;;; default value, the prototype instance of the class
 342 ;;; STANDARD-METHOD. This default value is also returned if the spec
 343 ;;; names an ordinary function or even a macro. In effect, this leaves
 344 ;;; the signalling of the appropriate error until load time.
 345 ;;;
 346 ;;; Note: During bootstrapping, this function is allowed to return NIL.
 347 (defun method-prototype-for-gf (name)
 348   (let ((gf? (and (gboundp name)
 349                   (gdefinition name))))
 350     (cond ((neq *boot-state* 'complete) nil)
 351           ((or (null gf?)
 352                (not (generic-function-p gf?)))          ; Someone else MIGHT
 353                                                         ; error at load time.
 354            (class-prototype (find-class 'standard-method)))
 355           (t
 356             (class-prototype (or (generic-function-method-class gf?)
 357                                  (find-class 'standard-method)))))))
 358 \f
 359 (defun expand-defmethod (name
 360                          proto-gf
 361                          proto-method
 362                          qualifiers
 363                          lambda-list
 364                          body
 365                          env)
 366   (multiple-value-bind (method-lambda unspecialized-lambda-list specializers)
 367       (add-method-declarations name qualifiers lambda-list body env)
 368     (multiple-value-bind (method-function-lambda initargs)
 369         (make-method-lambda proto-gf proto-method method-lambda env)
 370       (let ((initargs-form (make-method-initargs-form proto-gf
 371                                                       proto-method
 372                                                       method-function-lambda
 373                                                       initargs
 374                                                       env)))
 375         `(progn
 376           ;; Note: We could DECLAIM the ftype of the generic function
 377           ;; here, since ANSI specifies that we create it if it does
 378           ;; not exist. However, I chose not to, because I think it's
 379           ;; more useful to support a style of programming where every
 380           ;; generic function has an explicit DEFGENERIC and any typos
 381           ;; in DEFMETHODs are warned about. Otherwise
 382           ;;
 383           ;;   (DEFGENERIC FOO-BAR-BLETCH ((X T)))
 384           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X HASH-TABLE)) ..)
 385           ;;   (DEFMETHOD FOO-BRA-BLETCH ((X SIMPLE-VECTOR)) ..)
 386           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X VECTOR)) ..)
 387           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X ARRAY)) ..)
 388           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X LIST)) ..)
 389           ;;
 390           ;; compiles without raising an error and runs without
 391           ;; raising an error (since SIMPLE-VECTOR cases fall through
 392           ;; to VECTOR) but still doesn't do what was intended. I hate
 393           ;; that kind of bug (code which silently gives the wrong
 394           ;; answer), so we don't do a DECLAIM here. -- WHN 20000229
 395           ,(make-defmethod-form name qualifiers specializers
 396                                 unspecialized-lambda-list
 397                                 (if proto-method
 398                                     (class-name (class-of proto-method))
 399                                     'standard-method)
 400                                 initargs-form
 401                                 (getf (getf initargs :plist)
 402                                       :pv-table-symbol)))))))
 403
 404 (defun interned-symbol-p (x)
 405   (and (symbolp x) (symbol-package x)))
 406
 407 (defun make-defmethod-form (name qualifiers specializers
 408                                  unspecialized-lambda-list method-class-name
 409                                  initargs-form &optional pv-table-symbol)
 410   (let (fn
 411         fn-lambda)
 412     (if (and (interned-symbol-p (fun-name-block-name name))
 413              (every #'interned-symbol-p qualifiers)
 414              (every (lambda (s)
 415                       (if (consp s)
 416                           (and (eq (car s) 'eql)
 417                                (constantp (cadr s))
 418                                (let ((sv (eval (cadr s))))
 419                                  (or (interned-symbol-p sv)
 420                                      (integerp sv)
 421                                      (and (characterp sv)
 422                                           (standard-char-p sv)))))
 423                           (interned-symbol-p s)))
 424                     specializers)
 425              (consp initargs-form)
 426              (eq (car initargs-form) 'list*)
 427              (memq (cadr initargs-form) '(:function :fast-function))
 428              (consp (setq fn (caddr initargs-form)))
 429              (eq (car fn) 'function)
 430              (consp (setq fn-lambda (cadr fn)))
 431              (eq (car fn-lambda) 'lambda))
 432         (let* ((specls (mapcar (lambda (specl)
 433                                  (if (consp specl)
 434                                      `(,(car specl) ,(eval (cadr specl)))
 435                                    specl))
 436                                specializers))
 437                (mname `(,(if (eq (cadr initargs-form) :function)
 438                              'method 'fast-method)
 439                         ,name ,@qualifiers ,specls))
 440                (mname-sym (intern (let ((*print-pretty* nil)
 441                                         ;; (We bind *PACKAGE* to
 442                                         ;; KEYWORD here as a way to
 443                                         ;; force symbols to be printed
 444                                         ;; with explicit package
 445                                         ;; prefixes.)
 446                                         (*package* *keyword-package*))
 447                                     (format nil "~S" mname)))))
 448           `(progn
 449              (defun ,mname-sym ,(cadr fn-lambda)
 450                ,@(cddr fn-lambda))
 451              ,(make-defmethod-form-internal
 452                name qualifiers `',specls
 453                unspecialized-lambda-list method-class-name
 454                `(list* ,(cadr initargs-form)
 455                        #',mname-sym
 456                        ,@(cdddr initargs-form))
 457                pv-table-symbol)))
 458         (make-defmethod-form-internal
 459          name qualifiers
 460          `(list ,@(mapcar (lambda (specializer)
 461                             (if (consp specializer)
 462                                 ``(,',(car specializer)
 463                                    ,,(cadr specializer))
 464                                 `',specializer))
 465                           specializers))
 466          unspecialized-lambda-list
 467          method-class-name
 468          initargs-form
 469          pv-table-symbol))))
 470
 471 (defun make-defmethod-form-internal
 472     (name qualifiers specializers-form unspecialized-lambda-list
 473      method-class-name initargs-form &optional pv-table-symbol)
 474   `(load-defmethod
 475     ',method-class-name
 476     ',name
 477     ',qualifiers
 478     ,specializers-form
 479     ',unspecialized-lambda-list
 480     ,initargs-form
 481     ;; Paper over a bug in KCL by passing the cache-symbol here in
 482     ;; addition to in the list. FIXME: We should no longer need to do
 483     ;; this, since the CLOS code is now SBCL-specific, and doesn't
 484     ;; need to be ported to every buggy compiler in existence.
 485     ',pv-table-symbol))
 486
 487 (defmacro make-method-function (method-lambda &environment env)
 488   (make-method-function-internal method-lambda env))
 489
 490 (defun make-method-function-internal (method-lambda &optional env)
 491   (multiple-value-bind (proto-gf proto-method)
 492       (prototypes-for-make-method-lambda nil)
 493     (multiple-value-bind (method-function-lambda initargs)
 494         (make-method-lambda proto-gf proto-method method-lambda env)
 495       (make-method-initargs-form proto-gf
 496                                  proto-method
 497                                  method-function-lambda
 498                                  initargs
 499                                  env))))
 500
 501 (defun add-method-declarations (name qualifiers lambda-list body env)
 502   (declare (ignore env))
 503   (multiple-value-bind (parameters unspecialized-lambda-list specializers)
 504       (parse-specialized-lambda-list lambda-list)
 505     (declare (ignore parameters))
 506     (multiple-value-bind (real-body declarations documentation)
 507         (parse-body body)
 508       (values `(lambda ,unspecialized-lambda-list
 509                  ,@(when documentation `(,documentation))
 510                  ;; (Old PCL code used a somewhat different style of
 511                  ;; list for %METHOD-NAME values. Our names use
 512                  ;; ,@QUALIFIERS instead of ,QUALIFIERS so that the
 513                  ;; method names look more like what you see in a
 514                  ;; DEFMETHOD form.)
 515                  ;;
 516                  ;; FIXME: As of sbcl-0.7.0.6, code elsewhere, at
 517                  ;; least the code to set up named BLOCKs around the
 518                  ;; bodies of methods, depends on the function's base
 519                  ;; name being the first element of the %METHOD-NAME
 520                  ;; list. It would be good to remove this dependency,
 521                  ;; perhaps by building the BLOCK here, or by using
 522                  ;; another declaration (e.g. %BLOCK-NAME), so that
 523                  ;; our method debug names are free to have any format,
 524                  ;; e.g. (:METHOD PRINT-OBJECT :AROUND (CLOWN T)).
 525                  ;;
 526                  ;; Further, as of sbcl-0.7.9.10, the code to
 527                  ;; implement NO-NEXT-METHOD is coupled to the form of
 528                  ;; this declaration; see the definition of
 529                  ;; CALL-NO-NEXT-METHOD (and the passing of
 530                  ;; METHOD-NAME-DECLARATION arguments around the
 531                  ;; various CALL-NEXT-METHOD logic).
 532                  (declare (%method-name (,name
 533                                          ,@qualifiers
 534                                          ,specializers)))
 535                  (declare (%method-lambda-list ,@lambda-list))
 536                  ,@declarations
 537                  ,@real-body)
 538               unspecialized-lambda-list specializers))))
 539
 540 (defun real-make-method-initargs-form (proto-gf proto-method
 541                                        method-lambda initargs env)
 542   (declare (ignore proto-gf proto-method))
 543   (unless (and (consp method-lambda)
 544                (eq (car method-lambda) 'lambda))
 545     (error "The METHOD-LAMBDA argument to MAKE-METHOD-FUNCTION, ~S, ~
 546             is not a lambda form."
 547            method-lambda))
 548   (make-method-initargs-form-internal method-lambda initargs env))
 549
 550 (unless (fboundp 'make-method-initargs-form)
 551   (setf (gdefinition 'make-method-initargs-form)
 552         (symbol-function 'real-make-method-initargs-form)))
 553
 554 (defun real-make-method-lambda (proto-gf proto-method method-lambda env)
 555   (declare (ignore proto-gf proto-method))
 556   (make-method-lambda-internal method-lambda env))
 557
 558 ;;; a helper function for creating Python-friendly type declarations
 559 ;;; in DEFMETHOD forms
 560 (defun parameter-specializer-declaration-in-defmethod (parameter specializer)
 561   (cond ((and (consp specializer)
 562               (eq (car specializer) 'eql))
 563          ;; KLUDGE: ANSI, in its wisdom, says that
 564          ;; EQL-SPECIALIZER-FORMs in EQL specializers are evaluated at
 565          ;; DEFMETHOD expansion time. Thus, although one might think
 566          ;; that in
 567          ;;   (DEFMETHOD FOO ((X PACKAGE)
 568          ;;                   (Y (EQL 12))
 569          ;;      ..))
 570          ;; the PACKAGE and (EQL 12) forms are both parallel type
 571          ;; names, they're not, as is made clear when you do
 572          ;;   (DEFMETHOD FOO ((X PACKAGE)
 573          ;;                   (Y (EQL 'BAR)))
 574          ;;     ..)
 575          ;; where Y needs to be a symbol named "BAR", not some cons
 576          ;; made by (CONS 'QUOTE 'BAR). I.e. when the
 577          ;; EQL-SPECIALIZER-FORM is (EQL 'X), it requires an argument
 578          ;; to be of type (EQL X). It'd be easy to transform one to
 579          ;; the other, but it'd be somewhat messier to do so while
 580          ;; ensuring that the EQL-SPECIALIZER-FORM is only EVAL'd
 581          ;; once. (The new code wouldn't be messy, but it'd require a
 582          ;; big transformation of the old code.) So instead we punt.
 583          ;; -- WHN 20000610
 584          '(ignorable))
 585         ((member specializer
 586                  ;; KLUDGE: For some low-level implementation
 587                  ;; classes, perhaps because of some problems related
 588                  ;; to the incomplete integration of PCL into SBCL's
 589                  ;; type system, some specializer classes can't be
 590                  ;; declared as argument types. E.g.
 591                  ;;   (DEFMETHOD FOO ((X SLOT-OBJECT))
 592                  ;;     (DECLARE (TYPE SLOT-OBJECT X))
 593                  ;;     ..)
 594                  ;; loses when
 595                  ;;   (DEFSTRUCT BAR A B)
 596                  ;;   (FOO (MAKE-BAR))
 597                  ;; perhaps because of the way that STRUCTURE-OBJECT
 598                  ;; inherits both from SLOT-OBJECT and from
 599                  ;; SB-KERNEL:INSTANCE. In an effort to sweep such
 600                  ;; problems under the rug, we exclude these problem
 601                  ;; cases by blacklisting them here. -- WHN 2001-01-19
 602                  '(slot-object))
 603          '(ignorable))
 604         ((not (eq *boot-state* 'complete))
 605          ;; KLUDGE: PCL, in its wisdom, sometimes calls methods with
 606          ;; types which don't match their specializers. (Specifically,
 607          ;; it calls ENSURE-CLASS-USING-CLASS (T NULL) with a non-NULL
 608          ;; second argument.) Hopefully it only does this kind of
 609          ;; weirdness when bootstrapping.. -- WHN 20000610
 610          '(ignorable))
 611         (t
 612          ;; Otherwise, we can usually make Python very happy.
 613          (let ((type (info :type :kind specializer)))
 614            (ecase type
 615              ((:primitive :defined :instance :forthcoming-defclass-type)
 616               `(type ,specializer ,parameter))
 617              ((nil)
 618               (let ((class (find-class specializer nil)))
 619                 (if class
 620                     `(type ,(class-name class) ,parameter)
 621                     (progn
 622                       ;; we can get here, and still not have a failure
 623                       ;; case, by doing MOP programming like (PROGN
 624                       ;; (ENSURE-CLASS 'FOO) (DEFMETHOD BAR ((X FOO))
 625                       ;; ...)).  Best to let the user know we haven't
 626                       ;; been able to extract enough information:
 627                       (style-warn
 628                        "~@<can't find type for presumed class ~S in ~S.~@:>"
 629                        specializer
 630                        'parameter-specializer-declaration-in-defmethod)
 631                       '(ignorable))))))))))
 632
 633 (defun make-method-lambda-internal (method-lambda &optional env)
 634   (unless (and (consp method-lambda) (eq (car method-lambda) 'lambda))
 635     (error "The METHOD-LAMBDA argument to MAKE-METHOD-LAMBDA, ~S, ~
 636             is not a lambda form."
 637            method-lambda))
 638   (multiple-value-bind (real-body declarations documentation)
 639       (parse-body (cddr method-lambda))
 640     (let* ((name-decl (get-declaration '%method-name declarations))
 641            (sll-decl (get-declaration '%method-lambda-list declarations))
 642            (method-name (when (consp name-decl) (car name-decl)))
 643            (generic-function-name (when method-name (car method-name)))
 644            (specialized-lambda-list (or sll-decl (cadr method-lambda))))
 645       (multiple-value-bind (parameters lambda-list specializers)
 646           (parse-specialized-lambda-list specialized-lambda-list)
 647         (let* ((required-parameters
 648                 (mapcar (lambda (r s) (declare (ignore s)) r)
 649                         parameters
 650                         specializers))
 651                (slots (mapcar #'list required-parameters))
 652                (calls (list nil))
 653                (class-declarations
 654                 `(declare
 655                   ;; These declarations seem to be used by PCL to pass
 656                   ;; information to itself; when I tried to delete 'em
 657                   ;; ca. 0.6.10 it didn't work. I'm not sure how
 658                   ;; they work, but note the (VAR-DECLARATION '%CLASS ..)
 659                   ;; expression in CAN-OPTIMIZE-ACCESS1. -- WHN 2000-12-30
 660                   ,@(remove nil
 661                             (mapcar (lambda (a s) (and (symbolp s)
 662                                                        (neq s t)
 663                                                        `(%class ,a ,s)))
 664                                     parameters
 665                                     specializers))
 666                   ;; These TYPE declarations weren't in the original
 667                   ;; PCL code, but the Python compiler likes them a
 668                   ;; lot. (We're telling the compiler about our
 669                   ;; knowledge of specialized argument types so that
 670                   ;; it can avoid run-time type dispatch overhead,
 671                   ;; which can be a huge win for Python.)
 672                   ;;
 673                   ;; FIXME: Perhaps these belong in
 674                   ;; ADD-METHOD-DECLARATIONS instead of here?
 675                   ,@(mapcar #'parameter-specializer-declaration-in-defmethod
 676                             parameters
 677                             specializers)))
 678                (method-lambda
 679                 ;; Remove the documentation string and insert the
 680                 ;; appropriate class declarations. The documentation
 681                 ;; string is removed to make it easy for us to insert
 682                 ;; new declarations later, they will just go after the
 683                 ;; CADR of the method lambda. The class declarations
 684                 ;; are inserted to communicate the class of the method's
 685                 ;; arguments to the code walk.
 686                 `(lambda ,lambda-list
 687                    ;; The default ignorability of method parameters
 688                    ;; doesn't seem to be specified by ANSI. PCL had
 689                    ;; them basically ignorable but was a little
 690                    ;; inconsistent. E.g. even though the two
 691                    ;; method definitions
 692                    ;;   (DEFMETHOD FOO ((X T) (Y T)) "Z")
 693                    ;;   (DEFMETHOD FOO ((X T) Y) "Z")
 694                    ;; are otherwise equivalent, PCL treated Y as
 695                    ;; ignorable in the first definition but not in the
 696                    ;; second definition. We make all required
 697                    ;; parameters ignorable as a way of systematizing
 698                    ;; the old PCL behavior. -- WHN 2000-11-24
 699                    (declare (ignorable ,@required-parameters))
 700                    ,class-declarations
 701                    ,@declarations
 702                    (block ,(fun-name-block-name generic-function-name)
 703                      ,@real-body)))
 704                (constant-value-p (and (null (cdr real-body))
 705                                       (constantp (car real-body))))
 706                (constant-value (and constant-value-p
 707                                     (eval (car real-body))))
 708                (plist (and constant-value-p
 709                            (or (typep constant-value
 710                                       '(or number character))
 711                                (and (symbolp constant-value)
 712                                     (symbol-package constant-value)))
 713                            (list :constant-value constant-value)))
 714                (applyp (dolist (p lambda-list nil)
 715                          (cond ((memq p '(&optional &rest &key))
 716                                 (return t))
 717                                ((eq p '&aux)
 718                                 (return nil))))))
 719           (multiple-value-bind
 720               (walked-lambda call-next-method-p closurep next-method-p-p)
 721               (walk-method-lambda method-lambda
 722                                   required-parameters
 723                                   env
 724                                   slots
 725                                   calls)
 726             (multiple-value-bind (walked-lambda-body
 727                                   walked-declarations
 728                                   walked-documentation)
 729                 (parse-body (cddr walked-lambda))
 730               (declare (ignore walked-documentation))
 731               (when (or next-method-p-p call-next-method-p)
 732                 (setq plist (list* :needs-next-methods-p t plist)))
 733               (when (some #'cdr slots)
 734                 (multiple-value-bind (slot-name-lists call-list)
 735                     (slot-name-lists-from-slots slots calls)
 736                   (let ((pv-table-symbol (make-symbol "pv-table")))
 737                     (setq plist
 738                           `(,@(when slot-name-lists
 739                                 `(:slot-name-lists ,slot-name-lists))
 740                               ,@(when call-list
 741                                   `(:call-list ,call-list))
 742                               :pv-table-symbol ,pv-table-symbol
 743                               ,@plist))
 744                     (setq walked-lambda-body
 745                           `((pv-binding (,required-parameters
 746                                          ,slot-name-lists
 747                                          ,pv-table-symbol)
 748                                         ,@walked-lambda-body))))))
 749               (when (and (memq '&key lambda-list)
 750                          (not (memq '&allow-other-keys lambda-list)))
 751                 (let ((aux (memq '&aux lambda-list)))
 752                 (setq lambda-list (nconc (ldiff lambda-list aux)
 753                                          (list '&allow-other-keys)
 754                                          aux))))
 755               (values `(lambda (.method-args. .next-methods.)
 756                          (simple-lexical-method-functions
 757                           (,lambda-list .method-args. .next-methods.
 758                                         :call-next-method-p
 759                                         ,call-next-method-p
 760                                         :next-method-p-p ,next-method-p-p
 761                                         ;; we need to pass this along
 762                                         ;; so that NO-NEXT-METHOD can
 763                                         ;; be given a suitable METHOD
 764                                         ;; argument; we need the
 765                                         ;; QUALIFIERS and SPECIALIZERS
 766                                         ;; inside the declaration to
 767                                         ;; give to FIND-METHOD.
 768                                         :method-name-declaration ,name-decl
 769                                         :closurep ,closurep
 770                                         :applyp ,applyp)
 771                           ,@walked-declarations
 772                           ,@walked-lambda-body))
 773                       `(,@(when plist
 774                       `(:plist ,plist))
 775                           ,@(when documentation
 776                           `(:documentation ,documentation)))))))))))
 777
 778 (unless (fboundp 'make-method-lambda)
 779   (setf (gdefinition 'make-method-lambda)
 780         (symbol-function 'real-make-method-lambda)))
 781
 782 (defmacro simple-lexical-method-functions ((lambda-list
 783                                             method-args
 784                                             next-methods
 785                                             &rest lmf-options)
 786                                            &body body)
 787   `(progn
 788      ,method-args ,next-methods
 789      (bind-simple-lexical-method-macros (,method-args ,next-methods)
 790        (bind-lexical-method-functions (,@lmf-options)
 791          (bind-args (,lambda-list ,method-args)
 792            ,@body)))))
 793
 794 (defmacro fast-lexical-method-functions ((lambda-list
 795                                           next-method-call
 796                                           args
 797                                           rest-arg
 798                                           &rest lmf-options)
 799                                          &body body)
 800   `(bind-fast-lexical-method-macros (,args ,rest-arg ,next-method-call)
 801      (bind-lexical-method-functions (,@lmf-options)
 802        (bind-args (,(nthcdr (length args) lambda-list) ,rest-arg)
 803          ,@body))))
 804
 805 (defmacro bind-simple-lexical-method-macros ((method-args next-methods)
 806                                              &body body)
 807   `(macrolet ((call-next-method-bind (&body body)
 808                `(let ((.next-method. (car ,',next-methods))
 809                       (,',next-methods (cdr ,',next-methods)))
 810                  .next-method. ,',next-methods
 811                  ,@body))
 812               (call-next-method-body (method-name-declaration cnm-args)
 813                `(if .next-method.
 814                     (funcall (if (std-instance-p .next-method.)
 815                                  (method-function .next-method.)
 816                              .next-method.) ; for early methods
 817                              (or ,cnm-args ,',method-args)
 818                              ,',next-methods)
 819                     (apply #'call-no-next-method ',method-name-declaration
 820                             (or ,cnm-args ,',method-args))))
 821               (next-method-p-body ()
 822                `(not (null .next-method.)))
 823               (with-rebound-original-args ((call-next-method-p) &body body)
 824                 (declare (ignore call-next-method-p))
 825                 `(let () ,@body)))
 826     ,@body))
 827
 828 (defun call-no-next-method (method-name-declaration &rest args)
 829   (destructuring-bind (name) method-name-declaration
 830     (destructuring-bind (name &rest qualifiers-and-specializers) name
 831       ;; KLUDGE: inefficient traversal, but hey.  This should only
 832       ;; happen on the slow error path anyway.
 833       (let* ((qualifiers (butlast qualifiers-and-specializers))
 834              (specializers (car (last qualifiers-and-specializers)))
 835              (method (find-method (gdefinition name) qualifiers specializers)))
 836         (apply #'no-next-method
 837                (method-generic-function method)
 838                method
 839                args)))))
 840
 841 (defstruct (method-call (:copier nil))
 842   (function #'identity :type function)
 843   call-method-args)
 844
 845 #-sb-fluid (declaim (sb-ext:freeze-type method-call))
 846
 847 (defmacro invoke-method-call1 (function args cm-args)
 848   `(let ((.function. ,function)
 849          (.args. ,args)
 850          (.cm-args. ,cm-args))
 851      (if (and .cm-args. (null (cdr .cm-args.)))
 852          (funcall .function. .args. (car .cm-args.))
 853          (apply .function. .args. .cm-args.))))
 854
 855 (defmacro invoke-method-call (method-call restp &rest required-args+rest-arg)
 856   `(invoke-method-call1 (method-call-function ,method-call)
 857                         ,(if restp
 858                              `(list* ,@required-args+rest-arg)
 859                              `(list ,@required-args+rest-arg))
 860                         (method-call-call-method-args ,method-call)))
 861
 862 (defstruct (fast-method-call (:copier nil))
 863   (function #'identity :type function)
 864   pv-cell
 865   next-method-call
 866   arg-info)
 867
 868 #-sb-fluid (declaim (sb-ext:freeze-type fast-method-call))
 869
 870 (defmacro fmc-funcall (fn pv-cell next-method-call &rest args)
 871   `(funcall ,fn ,pv-cell ,next-method-call ,@args))
 872
 873 (defmacro invoke-fast-method-call (method-call &rest required-args+rest-arg)
 874   `(fmc-funcall (fast-method-call-function ,method-call)
 875                 (fast-method-call-pv-cell ,method-call)
 876                 (fast-method-call-next-method-call ,method-call)
 877                 ,@required-args+rest-arg))
 878
 879 (defstruct (fast-instance-boundp (:copier nil))
 880   (index 0 :type fixnum))
 881
 882 #-sb-fluid (declaim (sb-ext:freeze-type fast-instance-boundp))
 883
 884 (eval-when (:compile-toplevel :load-toplevel :execute)
 885   (defvar *allow-emf-call-tracing-p* nil)
 886   (defvar *enable-emf-call-tracing-p* #-sb-show nil #+sb-show t))
 887 \f
 888 ;;;; effective method functions
 889
 890 (defvar *emf-call-trace-size* 200)
 891 (defvar *emf-call-trace* nil)
 892 (defvar *emf-call-trace-index* 0)
 893
 894 ;;; This function was in the CMU CL version of PCL (ca Debian 2.4.8)
 895 ;;; without explanation. It appears to be intended for debugging, so
 896 ;;; it might be useful someday, so I haven't deleted it.
 897 ;;; But it isn't documented and isn't used for anything now, so
 898 ;;; I've conditionalized it out of the base system. -- WHN 19991213
 899 #+sb-show
 900 (defun show-emf-call-trace ()
 901   (when *emf-call-trace*
 902     (let ((j *emf-call-trace-index*)
 903           (*enable-emf-call-tracing-p* nil))
 904       (format t "~&(The oldest entries are printed first)~%")
 905       (dotimes-fixnum (i *emf-call-trace-size*)
 906         (let ((ct (aref *emf-call-trace* j)))
 907           (when ct (print ct)))
 908         (incf j)
 909         (when (= j *emf-call-trace-size*)
 910           (setq j 0))))))
 911
 912 (defun trace-emf-call-internal (emf format args)
 913   (unless *emf-call-trace*
 914     (setq *emf-call-trace* (make-array *emf-call-trace-size*)))
 915   (setf (aref *emf-call-trace* *emf-call-trace-index*)
 916         (list* emf format args))
 917   (incf *emf-call-trace-index*)
 918   (when (= *emf-call-trace-index* *emf-call-trace-size*)
 919     (setq *emf-call-trace-index* 0)))
 920
 921 (defmacro trace-emf-call (emf format args)
 922   (when *allow-emf-call-tracing-p*
 923     `(when *enable-emf-call-tracing-p*
 924        (trace-emf-call-internal ,emf ,format ,args))))
 925
 926 (defmacro invoke-effective-method-function-fast
 927     (emf restp &rest required-args+rest-arg)
 928   `(progn
 929      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 930      (invoke-fast-method-call ,emf ,@required-args+rest-arg)))
 931
 932 (defmacro invoke-effective-method-function (emf restp
 933                                                 &rest required-args+rest-arg)
 934   (unless (constantp restp)
 935     (error "The RESTP argument is not constant."))
 936   ;; FIXME: The RESTP handling here is confusing and maybe slightly
 937   ;; broken if RESTP evaluates to a non-self-evaluating form. E.g. if
 938   ;;   (INVOKE-EFFECTIVE-METHOD-FUNCTION EMF '(ERROR "gotcha") ...)
 939   ;; then TRACE-EMF-CALL-CALL-INTERNAL might die on a gotcha error.
 940   (setq restp (eval restp))
 941   `(progn
 942      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 943      (cond ((typep ,emf 'fast-method-call)
 944             (invoke-fast-method-call ,emf ,@required-args+rest-arg))
 945            ;; "What," you may wonder, "do these next two clauses do?"
 946            ;; In that case, you are not a PCL implementor, for they
 947            ;; considered this to be self-documenting.:-| Or CSR, for
 948            ;; that matter, since he can also figure it out by looking
 949            ;; at it without breaking stride. For the rest of us,
 950            ;; though: From what the code is doing with .SLOTS. and
 951            ;; whatnot, evidently it's implementing SLOT-VALUEish and
 952            ;; GET-SLOT-VALUEish things. Then we can reason backwards
 953            ;; and conclude that setting EMF to a FIXNUM is an
 954            ;; optimized way to represent these slot access operations.
 955            ,@(when (and (null restp) (= 1 (length required-args+rest-arg)))
 956                `(((typep ,emf 'fixnum)
 957                   (let* ((.slots. (get-slots-or-nil
 958                                    ,(car required-args+rest-arg)))
 959                          (value (when .slots. (clos-slots-ref .slots. ,emf))))
 960                     (if (eq value +slot-unbound+)
 961                         (slot-unbound-internal ,(car required-args+rest-arg)
 962                                                ,emf)
 963                         value)))))
 964            ,@(when (and (null restp) (= 2 (length required-args+rest-arg)))
 965                `(((typep ,emf 'fixnum)
 966                   (let ((.new-value. ,(car required-args+rest-arg))
 967                         (.slots. (get-slots-or-nil
 968                                   ,(cadr required-args+rest-arg))))
 969                     (when .slots.
 970                       (setf (clos-slots-ref .slots. ,emf) .new-value.))))))
 971            ;; (In cmucl-2.4.8 there was a commented-out third ,@(WHEN
 972            ;; ...) clause here to handle SLOT-BOUNDish stuff. Since
 973            ;; there was no explanation and presumably the code is 10+
 974            ;; years stale, I simply deleted it. -- WHN)
 975            (t
 976             (etypecase ,emf
 977               (method-call
 978                (invoke-method-call ,emf ,restp ,@required-args+rest-arg))
 979               (function
 980                ,(if restp
 981                     `(apply (the function ,emf) ,@required-args+rest-arg)
 982                     `(funcall (the function ,emf)
 983                               ,@required-args+rest-arg))))))))
 984
 985 (defun invoke-emf (emf args)
 986   (trace-emf-call emf t args)
 987   (etypecase emf
 988     (fast-method-call
 989      (let* ((arg-info (fast-method-call-arg-info emf))
 990             (restp (cdr arg-info))
 991             (nreq (car arg-info)))
 992        (if restp
 993            (let* ((rest-args (nthcdr nreq args))
 994                   (req-args (ldiff args rest-args)))
 995              (apply (fast-method-call-function emf)
 996                     (fast-method-call-pv-cell emf)
 997                     (fast-method-call-next-method-call emf)
 998                     (nconc req-args (list rest-args))))
 999            (cond ((null args)
1000                   (if (eql nreq 0)
1001                       (invoke-fast-method-call emf)
1002                       (error "wrong number of args")))
1003                  ((null (cdr args))
1004                   (if (eql nreq 1)
1005                       (invoke-fast-method-call emf (car args))
1006                       (error "wrong number of args")))
1007                  ((null (cddr args))
1008                   (if (eql nreq 2)
1009                       (invoke-fast-method-call emf (car args) (cadr args))
1010                       (error "wrong number of args")))
1011                  (t
1012                   (apply (fast-method-call-function emf)
1013                          (fast-method-call-pv-cell emf)
1014                          (fast-method-call-next-method-call emf)
1015                          args))))))
1016     (method-call
1017      (apply (method-call-function emf)
1018             args
1019             (method-call-call-method-args emf)))
1020     (fixnum
1021      (cond ((null args) (error "1 or 2 args were expected."))
1022            ((null (cdr args))
1023             (let* ((slots (get-slots (car args)))
1024                    (value (clos-slots-ref slots emf)))
1025               (if (eq value +slot-unbound+)
1026                   (slot-unbound-internal (car args) emf)
1027                   value)))
1028            ((null (cddr args))
1029              (setf (clos-slots-ref (get-slots (cadr args)) emf)
1030                    (car args)))
1031            (t (error "1 or 2 args were expected."))))
1032     (fast-instance-boundp
1033      (if (or (null args) (cdr args))
1034          (error "1 arg was expected.")
1035        (let ((slots (get-slots (car args))))
1036          (not (eq (clos-slots-ref slots
1037                                   (fast-instance-boundp-index emf))
1038                   +slot-unbound+)))))
1039     (function
1040      (apply emf args))))
1041 \f
1042 (defmacro bind-fast-lexical-method-macros ((args rest-arg next-method-call)
1043                                            &body body)
1044   (let* ((all-params (append args (when rest-arg (list rest-arg))))
1045          (rebindings (mapcar (lambda (x) (list x x)) all-params)))
1046     `(macrolet ((narrowed-emf (emf)
1047                  ;; INVOKE-EFFECTIVE-METHOD-FUNCTION has code in it to
1048                  ;; dispatch on the possibility that EMF might be of
1049                  ;; type FIXNUM (as an optimized representation of a
1050                  ;; slot accessor). But as far as I (WHN 2002-06-11)
1051                  ;; can tell, it's impossible for such a representation
1052                  ;; to end up as .NEXT-METHOD-CALL. By reassuring
1053                  ;; INVOKE-E-M-F that when called from this context
1054                  ;; it needn't worry about the FIXNUM case, we can
1055                  ;; keep those cases from being compiled, which is
1056                  ;; good both because it saves bytes and because it
1057                  ;; avoids annoying type mismatch compiler warnings.
1058                  ;;
1059                  ;; KLUDGE: In sbcl-0.7.4.29, the compiler's type
1060                  ;; system isn't smart enough about NOT and
1061                  ;; intersection types to benefit from a (NOT FIXNUM)
1062                  ;; declaration here. -- WHN 2002-06-12 (FIXME: maybe
1063                  ;; it is now... -- CSR, 2003-06-07)
1064                  ;;
1065                  ;; FIXME: Might the FUNCTION type be omittable here,
1066                  ;; leaving only METHOD-CALLs? Failing that, could this
1067                  ;; be documented somehow? (It'd be nice if the types
1068                  ;; involved could be understood without solving the
1069                  ;; halting problem.)
1070                  `(the (or function method-call fast-method-call)
1071                    ,emf))
1072                 (call-next-method-bind (&body body)
1073                  `(let () ,@body))
1074                 (call-next-method-body (method-name-declaration cnm-args)
1075                  `(if ,',next-method-call
1076                       ,(locally
1077                         ;; This declaration suppresses a "deleting
1078                         ;; unreachable code" note for the following IF
1079                         ;; when REST-ARG is NIL. It is not nice for
1080                         ;; debugging SBCL itself, but at least it
1081                         ;; keeps us from annoying users.
1082                         (declare (optimize (inhibit-warnings 3)))
1083                         (if (and (null ',rest-arg)
1084                                  (consp cnm-args)
1085                                  (eq (car cnm-args) 'list))
1086                             `(invoke-effective-method-function
1087                               (narrowed-emf ,',next-method-call)
1088                               nil
1089                               ,@(cdr cnm-args))
1090                             (let ((call `(invoke-effective-method-function
1091                                           (narrowed-emf ,',next-method-call)
1092                                           ,',(not (null rest-arg))
1093                                           ,@',args
1094                                           ,@',(when rest-arg `(,rest-arg)))))
1095                               `(if ,cnm-args
1096                                 (bind-args ((,@',args
1097                                              ,@',(when rest-arg
1098                                                        `(&rest ,rest-arg)))
1099                                             ,cnm-args)
1100                                  ,call)
1101                                 ,call))))
1102                       ,(locally
1103                         ;; As above, this declaration suppresses code
1104                         ;; deletion notes.
1105                         (declare (optimize (inhibit-warnings 3)))
1106                         (if (and (null ',rest-arg)
1107                                  (consp cnm-args)
1108                                  (eq (car cnm-args) 'list))
1109                             `(call-no-next-method ',method-name-declaration
1110                               ,@(cdr cnm-args))
1111                             `(call-no-next-method ',method-name-declaration
1112                               ,@',args
1113                               ,@',(when rest-arg
1114                                         `(,rest-arg)))))))
1115                 (next-method-p-body ()
1116                  `(not (null ,',next-method-call)))
1117                 (with-rebound-original-args ((cnm-p) &body body)
1118                   (if cnm-p
1119                       `(let ,',rebindings
1120                         (declare (ignorable ,@',all-params))
1121                         ,@body)
1122                       `(let () ,@body))))
1123       ,@body)))
1124
1125 (defmacro bind-lexical-method-functions
1126     ((&key call-next-method-p next-method-p-p
1127            closurep applyp method-name-declaration)
1128      &body body)
1129   (cond ((and (null call-next-method-p) (null next-method-p-p)
1130               (null closurep) (null applyp))
1131          `(let () ,@body))
1132         (t
1133          `(call-next-method-bind
1134             (flet (,@(and call-next-method-p
1135                           `((call-next-method (&rest cnm-args)
1136                              (call-next-method-body
1137                               ,method-name-declaration
1138                               cnm-args))))
1139                    ,@(and next-method-p-p
1140                           '((next-method-p ()
1141                              (next-method-p-body)))))
1142               (with-rebound-original-args (,call-next-method-p)
1143                 ,@body))))))
1144
1145 (defmacro bind-args ((lambda-list args) &body body)
1146   (let ((args-tail '.args-tail.)
1147         (key '.key.)
1148         (state 'required))
1149     (flet ((process-var (var)
1150              (if (memq var lambda-list-keywords)
1151                  (progn
1152                    (case var
1153                      (&optional       (setq state 'optional))
1154                      (&key            (setq state 'key))
1155                      (&allow-other-keys)
1156                      (&rest           (setq state 'rest))
1157                      (&aux            (setq state 'aux))
1158                      (otherwise
1159                       (error
1160                        "encountered the non-standard lambda list keyword ~S"
1161                        var)))
1162                    nil)
1163                  (case state
1164                    (required `((,var (pop ,args-tail))))
1165                    (optional (cond ((not (consp var))
1166                                     `((,var (when ,args-tail
1167                                               (pop ,args-tail)))))
1168                                    ((null (cddr var))
1169                                     `((,(car var) (if ,args-tail
1170                                                       (pop ,args-tail)
1171                                                       ,(cadr var)))))
1172                                    (t
1173                                     `((,(caddr var) ,args-tail)
1174                                       (,(car var) (if ,args-tail
1175                                                       (pop ,args-tail)
1176                                                       ,(cadr var)))))))
1177                    (rest `((,var ,args-tail)))
1178                    (key (cond ((not (consp var))
1179                                `((,var (car
1180                                         (get-key-arg-tail ,(keywordicate var)
1181                                                           ,args-tail)))))
1182                               ((null (cddr var))
1183                                (multiple-value-bind (keyword variable)
1184                                    (if (consp (car var))
1185                                        (values (caar var)
1186                                                (cadar var))
1187                                        (values (keywordicate (car var))
1188                                                (car var)))
1189                                  `((,key (get-key-arg-tail ',keyword
1190                                                            ,args-tail))
1191                                    (,variable (if ,key
1192                                                   (car ,key)
1193                                                   ,(cadr var))))))
1194                               (t
1195                                (multiple-value-bind (keyword variable)
1196                                    (if (consp (car var))
1197                                        (values (caar var)
1198                                                (cadar var))
1199                                        (values (keywordicate (car var))
1200                                                (car var)))
1201                                  `((,key (get-key-arg-tail ',keyword
1202                                                            ,args-tail))
1203                                    (,(caddr var) ,key)
1204                                    (,variable (if ,key
1205                                                   (car ,key)
1206                                                   ,(cadr var))))))))
1207                    (aux `(,var))))))
1208       (let ((bindings (mapcan #'process-var lambda-list)))
1209         `(let* ((,args-tail ,args)
1210                 ,@bindings
1211                 (.dummy0.
1212                  ,@(when (eq state 'optional)
1213                      `((unless (null ,args-tail)
1214                          (error 'simple-program-error
1215                                 :format-control "surplus arguments: ~S"
1216                                 :format-arguments (list ,args-tail)))))))
1217            (declare (ignorable ,args-tail .dummy0.))
1218            ,@body)))))
1219
1220 (defun get-key-arg-tail (keyword list)
1221   (loop for (key . tail) on list by #'cddr
1222         when (null tail) do
1223           ;; FIXME: Do we want to export this symbol? Or maybe use an
1224           ;; (ERROR 'SIMPLE-PROGRAM-ERROR) form?
1225           (sb-c::%odd-key-args-error)
1226         when (eq key keyword)
1227           return tail))
1228
1229 (defun walk-method-lambda (method-lambda required-parameters env slots calls)
1230   (let ((call-next-method-p nil)   ; flag indicating that CALL-NEXT-METHOD
1231                                    ; should be in the method definition
1232         (closurep nil)             ; flag indicating that #'CALL-NEXT-METHOD
1233                                    ; was seen in the body of a method
1234         (next-method-p-p nil))     ; flag indicating that NEXT-METHOD-P
1235                                    ; should be in the method definition
1236     (flet ((walk-function (form context env)
1237              (cond ((not (eq context :eval)) form)
1238                    ;; FIXME: Jumping to a conclusion from the way it's used
1239                    ;; above, perhaps CONTEXT should be called SITUATION
1240                    ;; (after the term used in the ANSI specification of
1241                    ;; EVAL-WHEN) and given modern ANSI keyword values
1242                    ;; like :LOAD-TOPLEVEL.
1243                    ((not (listp form)) form)
1244                    ((eq (car form) 'call-next-method)
1245                     (setq call-next-method-p t)
1246                     form)
1247                    ((eq (car form) 'next-method-p)
1248                     (setq next-method-p-p t)
1249                     form)
1250                    ((and (eq (car form) 'function)
1251                          (cond ((eq (cadr form) 'call-next-method)
1252                                 (setq call-next-method-p t)
1253                                 (setq closurep t)
1254                                 form)
1255                                ((eq (cadr form) 'next-method-p)
1256                                 (setq next-method-p-p t)
1257                                 (setq closurep t)
1258                                 form)
1259                                (t nil))))
1260                    ((and (memq (car form)
1261                                '(slot-value set-slot-value slot-boundp))
1262                          (constantp (caddr form)))
1263                      (let ((parameter (can-optimize-access form
1264                                                            required-parameters
1265                                                            env)))
1266                       (let ((fun (ecase (car form)
1267                                    (slot-value #'optimize-slot-value)
1268                                    (set-slot-value #'optimize-set-slot-value)
1269                                    (slot-boundp #'optimize-slot-boundp))))
1270                         (funcall fun slots parameter form))))
1271                    ((and (eq (car form) 'apply)
1272                          (consp (cadr form))
1273                          (eq (car (cadr form)) 'function)
1274                          (generic-function-name-p (cadr (cadr form))))
1275                     (optimize-generic-function-call
1276                      form required-parameters env slots calls))
1277                    ((generic-function-name-p (car form))
1278                     (optimize-generic-function-call
1279                      form required-parameters env slots calls))
1280                    (t form))))
1281
1282       (let ((walked-lambda (walk-form method-lambda env #'walk-function)))
1283         (values walked-lambda
1284                 call-next-method-p
1285                 closurep
1286                 next-method-p-p)))))
1287
1288 (defun generic-function-name-p (name)
1289   (and (legal-fun-name-p name)
1290        (gboundp name)
1291        (if (eq *boot-state* 'complete)
1292            (standard-generic-function-p (gdefinition name))
1293            (funcallable-instance-p (gdefinition name)))))
1294 \f
1295 (defvar *method-function-plist* (make-hash-table :test 'eq))
1296 (defvar *mf1* nil)
1297 (defvar *mf1p* nil)
1298 (defvar *mf1cp* nil)
1299 (defvar *mf2* nil)
1300 (defvar *mf2p* nil)
1301 (defvar *mf2cp* nil)
1302
1303 (defun method-function-plist (method-function)
1304   (unless (eq method-function *mf1*)
1305     (rotatef *mf1* *mf2*)
1306     (rotatef *mf1p* *mf2p*)
1307     (rotatef *mf1cp* *mf2cp*))
1308   (unless (or (eq method-function *mf1*) (null *mf1cp*))
1309     (setf (gethash *mf1* *method-function-plist*) *mf1p*))
1310   (unless (eq method-function *mf1*)
1311     (setf *mf1* method-function
1312           *mf1cp* nil
1313           *mf1p* (gethash method-function *method-function-plist*)))
1314   *mf1p*)
1315
1316 (defun (setf method-function-plist)
1317     (val method-function)
1318   (unless (eq method-function *mf1*)
1319     (rotatef *mf1* *mf2*)
1320     (rotatef *mf1cp* *mf2cp*)
1321     (rotatef *mf1p* *mf2p*))
1322   (unless (or (eq method-function *mf1*) (null *mf1cp*))
1323     (setf (gethash *mf1* *method-function-plist*) *mf1p*))
1324   (setf *mf1* method-function
1325         *mf1cp* t
1326         *mf1p* val))
1327
1328 (defun method-function-get (method-function key &optional default)
1329   (getf (method-function-plist method-function) key default))
1330
1331 (defun (setf method-function-get)
1332     (val method-function key)
1333   (setf (getf (method-function-plist method-function) key) val))
1334
1335 (defun method-function-pv-table (method-function)
1336   (method-function-get method-function :pv-table))
1337
1338 (defun method-function-method (method-function)
1339   (method-function-get method-function :method))
1340
1341 (defun method-function-needs-next-methods-p (method-function)
1342   (method-function-get method-function :needs-next-methods-p t))
1343 \f
1344 (defmacro method-function-closure-generator (method-function)
1345   `(method-function-get ,method-function 'closure-generator))
1346
1347 (defun load-defmethod
1348     (class name quals specls ll initargs &optional pv-table-symbol)
1349   (setq initargs (copy-tree initargs))
1350   (let ((method-spec (or (getf initargs :method-spec)
1351                          (make-method-spec name quals specls))))
1352     (setf (getf initargs :method-spec) method-spec)
1353     (load-defmethod-internal class name quals specls
1354                              ll initargs pv-table-symbol)))
1355
1356 (defun load-defmethod-internal
1357     (method-class gf-spec qualifiers specializers lambda-list
1358                   initargs pv-table-symbol)
1359   (when pv-table-symbol
1360     (setf (getf (getf initargs :plist) :pv-table-symbol)
1361           pv-table-symbol))
1362   (when (and (eq *boot-state* 'complete)
1363              (fboundp gf-spec))
1364     (let* ((gf (fdefinition gf-spec))
1365            (method (and (generic-function-p gf)
1366                         (generic-function-methods gf)
1367                         (find-method gf
1368                                      qualifiers
1369                                      (parse-specializers specializers)
1370                                      nil))))
1371       (when method
1372         (style-warn "redefining ~S~{ ~S~} ~S in DEFMETHOD"
1373                     gf-spec qualifiers specializers))))
1374   (let ((method (apply #'add-named-method
1375                        gf-spec qualifiers specializers lambda-list
1376                        :definition-source `((defmethod ,gf-spec
1377                                                 ,@qualifiers
1378                                               ,specializers)
1379                                             ,*load-pathname*)
1380                        initargs)))
1381     (unless (or (eq method-class 'standard-method)
1382                 (eq (find-class method-class nil) (class-of method)))
1383       ;; FIXME: should be STYLE-WARNING?
1384       (format *error-output*
1385               "~&At the time the method with qualifiers ~:S and~%~
1386                specializers ~:S on the generic function ~S~%~
1387                was compiled, the method-class for that generic function was~%~
1388                ~S. But, the method class is now ~S, this~%~
1389                may mean that this method was compiled improperly.~%"
1390               qualifiers specializers gf-spec
1391               method-class (class-name (class-of method))))
1392     method))
1393
1394 (defun make-method-spec (gf-spec qualifiers unparsed-specializers)
1395   `(method ,gf-spec ,@qualifiers ,unparsed-specializers))
1396
1397 (defun initialize-method-function (initargs &optional return-function-p method)
1398   (let* ((mf (getf initargs :function))
1399          (method-spec (getf initargs :method-spec))
1400          (plist (getf initargs :plist))
1401          (pv-table-symbol (getf plist :pv-table-symbol))
1402          (pv-table nil)
1403          (mff (getf initargs :fast-function)))
1404     (flet ((set-mf-property (p v)
1405              (when mf
1406                (setf (method-function-get mf p) v))
1407              (when mff
1408                (setf (method-function-get mff p) v))))
1409       (when method-spec
1410         (when mf
1411           (setq mf (set-fun-name mf method-spec)))
1412         (when mff
1413           (let ((name `(,(or (get (car method-spec) 'fast-sym)
1414                              (setf (get (car method-spec) 'fast-sym)
1415                                    ;; KLUDGE: If we're going to be
1416                                    ;; interning private symbols in our
1417                                    ;; a this way, it would be cleanest
1418                                    ;; to use a separate package
1419                                    ;; %PCL-PRIVATE or something, and
1420                                    ;; failing that, to use a special
1421                                    ;; symbol prefix denoting privateness.
1422                                    ;; -- WHN 19991201
1423                                    (intern (format nil "FAST-~A"
1424                                                    (car method-spec))
1425                                            *pcl-package*)))
1426                          ,@(cdr method-spec))))
1427             (set-fun-name mff name)
1428             (unless mf
1429               (set-mf-property :name name)))))
1430       (when plist
1431         (let ((snl (getf plist :slot-name-lists))
1432               (cl (getf plist :call-list)))
1433           (when (or snl cl)
1434             (setq pv-table (intern-pv-table :slot-name-lists snl
1435                                             :call-list cl))
1436             (when pv-table (set pv-table-symbol pv-table))
1437             (set-mf-property :pv-table pv-table)))
1438         (loop (when (null plist) (return nil))
1439               (set-mf-property (pop plist) (pop plist)))
1440         (when method
1441           (set-mf-property :method method))
1442         (when return-function-p
1443           (or mf (method-function-from-fast-function mff)))))))
1444 \f
1445 (defun analyze-lambda-list (lambda-list)
1446   (flet (;; FIXME: Is this redundant with SB-C::MAKE-KEYWORD-FOR-ARG?
1447          (parse-key-arg (arg)
1448            (if (listp arg)
1449                (if (listp (car arg))
1450                    (caar arg)
1451                    (keywordicate (car arg)))
1452                (keywordicate arg))))
1453     (let ((nrequired 0)
1454           (noptional 0)
1455           (keysp nil)
1456           (restp nil)
1457           (nrest 0)
1458           (allow-other-keys-p nil)
1459           (keywords ())
1460           (keyword-parameters ())
1461           (state 'required))
1462       (dolist (x lambda-list)
1463         (if (memq x lambda-list-keywords)
1464             (case x
1465               (&optional         (setq state 'optional))
1466               (&key              (setq keysp t
1467                                        state 'key))
1468               (&allow-other-keys (setq allow-other-keys-p t))
1469               (&rest             (setq restp t
1470                                        state 'rest))
1471               (&aux           (return t))
1472               (otherwise
1473                 (error "encountered the non-standard lambda list keyword ~S"
1474                        x)))
1475             (ecase state
1476               (required  (incf nrequired))
1477               (optional  (incf noptional))
1478               (key       (push (parse-key-arg x) keywords)
1479                          (push x keyword-parameters))
1480               (rest      (incf nrest)))))
1481       (when (and restp (zerop nrest))
1482         (error "Error in lambda-list:~%~
1483                 After &REST, a DEFGENERIC lambda-list ~
1484                 must be followed by at least one variable."))
1485       (values nrequired noptional keysp restp allow-other-keys-p
1486               (reverse keywords)
1487               (reverse keyword-parameters)))))
1488
1489 (defun keyword-spec-name (x)
1490   (let ((key (if (atom x) x (car x))))
1491     (if (atom key)
1492         (keywordicate key)
1493         (car key))))
1494
1495 (defun ftype-declaration-from-lambda-list (lambda-list name)
1496   (multiple-value-bind (nrequired noptional keysp restp allow-other-keys-p
1497                                   keywords keyword-parameters)
1498       (analyze-lambda-list lambda-list)
1499     (declare (ignore keyword-parameters))
1500     (let* ((old (info :function :type name)) ;FIXME:FDOCUMENTATION instead?
1501            (old-ftype (if (fun-type-p old) old nil))
1502            (old-restp (and old-ftype (fun-type-rest old-ftype)))
1503            (old-keys (and old-ftype
1504                           (mapcar #'key-info-name
1505                                   (fun-type-keywords
1506                                    old-ftype))))
1507            (old-keysp (and old-ftype (fun-type-keyp old-ftype)))
1508            (old-allowp (and old-ftype
1509                             (fun-type-allowp old-ftype)))
1510            (keywords (union old-keys (mapcar #'keyword-spec-name keywords))))
1511       `(function ,(append (make-list nrequired :initial-element t)
1512                           (when (plusp noptional)
1513                             (append '(&optional)
1514                                     (make-list noptional :initial-element t)))
1515                           (when (or restp old-restp)
1516                             '(&rest t))
1517                           (when (or keysp old-keysp)
1518                             (append '(&key)
1519                                     (mapcar (lambda (key)
1520                                               `(,key t))
1521                                             keywords)
1522                                     (when (or allow-other-keys-p old-allowp)
1523                                       '(&allow-other-keys)))))
1524                  *))))
1525
1526 (defun defgeneric-declaration (spec lambda-list)
1527   `(ftype ,(ftype-declaration-from-lambda-list lambda-list spec) ,spec))
1528 \f
1529 ;;;; early generic function support
1530
1531 (defvar *!early-generic-functions* ())
1532
1533 (defun ensure-generic-function (fun-name
1534                                 &rest all-keys
1535                                 &key environment
1536                                 &allow-other-keys)
1537   (declare (ignore environment))
1538   (let ((existing (and (gboundp fun-name)
1539                        (gdefinition fun-name))))
1540     (if (and existing
1541              (eq *boot-state* 'complete)
1542              (null (generic-function-p existing)))
1543         (generic-clobbers-function fun-name)
1544         (apply #'ensure-generic-function-using-class
1545                existing fun-name all-keys))))
1546
1547 (defun generic-clobbers-function (fun-name)
1548   (error 'simple-program-error
1549          :format-control "~S already names an ordinary function or a macro."
1550          :format-arguments (list fun-name)))
1551
1552 (defvar *sgf-wrapper*
1553   (boot-make-wrapper (early-class-size 'standard-generic-function)
1554                      'standard-generic-function))
1555
1556 (defvar *sgf-slots-init*
1557   (mapcar (lambda (canonical-slot)
1558             (if (memq (getf canonical-slot :name) '(arg-info source))
1559                 +slot-unbound+
1560                 (let ((initfunction (getf canonical-slot :initfunction)))
1561                   (if initfunction
1562                       (funcall initfunction)
1563                       +slot-unbound+))))
1564           (early-collect-inheritance 'standard-generic-function)))
1565
1566 (defvar *sgf-method-class-index*
1567   (!bootstrap-slot-index 'standard-generic-function 'method-class))
1568
1569 (defun early-gf-p (x)
1570   (and (fsc-instance-p x)
1571        (eq (clos-slots-ref (get-slots x) *sgf-method-class-index*)
1572            +slot-unbound+)))
1573
1574 (defvar *sgf-methods-index*
1575   (!bootstrap-slot-index 'standard-generic-function 'methods))
1576
1577 (defmacro early-gf-methods (gf)
1578   `(clos-slots-ref (get-slots ,gf) *sgf-methods-index*))
1579
1580 (defvar *sgf-arg-info-index*
1581   (!bootstrap-slot-index 'standard-generic-function 'arg-info))
1582
1583 (defmacro early-gf-arg-info (gf)
1584   `(clos-slots-ref (get-slots ,gf) *sgf-arg-info-index*))
1585
1586 (defvar *sgf-dfun-state-index*
1587   (!bootstrap-slot-index 'standard-generic-function 'dfun-state))
1588
1589 (defstruct (arg-info
1590             (:conc-name nil)
1591             (:constructor make-arg-info ())
1592             (:copier nil))
1593   (arg-info-lambda-list :no-lambda-list)
1594   arg-info-precedence
1595   arg-info-metatypes
1596   arg-info-number-optional
1597   arg-info-key/rest-p
1598   arg-info-keys   ;nil        no &KEY or &REST allowed
1599                   ;(k1 k2 ..) Each method must accept these &KEY arguments.
1600                   ;T          must have &KEY or &REST
1601
1602   gf-info-simple-accessor-type ; nil, reader, writer, boundp
1603   (gf-precompute-dfun-and-emf-p nil) ; set by set-arg-info
1604
1605   gf-info-static-c-a-m-emf
1606   (gf-info-c-a-m-emf-std-p t)
1607   gf-info-fast-mf-p)
1608
1609 #-sb-fluid (declaim (sb-ext:freeze-type arg-info))
1610
1611 (defun arg-info-valid-p (arg-info)
1612   (not (null (arg-info-number-optional arg-info))))
1613
1614 (defun arg-info-applyp (arg-info)
1615   (or (plusp (arg-info-number-optional arg-info))
1616       (arg-info-key/rest-p arg-info)))
1617
1618 (defun arg-info-number-required (arg-info)
1619   (length (arg-info-metatypes arg-info)))
1620
1621 (defun arg-info-nkeys (arg-info)
1622   (count-if (lambda (x) (neq x t)) (arg-info-metatypes arg-info)))
1623
1624 ;;; Keep pages clean by not setting if the value is already the same.
1625 (defmacro esetf (pos val)
1626   (with-unique-names (valsym)
1627     `(let ((,valsym ,val))
1628        (unless (equal ,pos ,valsym)
1629          (setf ,pos ,valsym)))))
1630
1631 (defun set-arg-info (gf &key new-method (lambda-list nil lambda-list-p)
1632                         argument-precedence-order)
1633   (let* ((arg-info (if (eq *boot-state* 'complete)
1634                        (gf-arg-info gf)
1635                        (early-gf-arg-info gf)))
1636          (methods (if (eq *boot-state* 'complete)
1637                       (generic-function-methods gf)
1638                       (early-gf-methods gf)))
1639          (was-valid-p (integerp (arg-info-number-optional arg-info)))
1640          (first-p (and new-method (null (cdr methods)))))
1641     (when (and (not lambda-list-p) methods)
1642       (setq lambda-list (gf-lambda-list gf)))
1643     (when (or lambda-list-p
1644               (and first-p
1645                    (eq (arg-info-lambda-list arg-info) :no-lambda-list)))
1646       (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1647           (analyze-lambda-list lambda-list)
1648         (when (and methods (not first-p))
1649           (let ((gf-nreq (arg-info-number-required arg-info))
1650                 (gf-nopt (arg-info-number-optional arg-info))
1651                 (gf-key/rest-p (arg-info-key/rest-p arg-info)))
1652             (unless (and (= nreq gf-nreq)
1653                          (= nopt gf-nopt)
1654                          (eq (or keysp restp) gf-key/rest-p))
1655               (error "The lambda-list ~S is incompatible with ~
1656                      existing methods of ~S."
1657                      lambda-list gf))))
1658         (when lambda-list-p
1659           (esetf (arg-info-lambda-list arg-info) lambda-list))
1660         (when (or lambda-list-p argument-precedence-order
1661                   (null (arg-info-precedence arg-info)))
1662           (esetf (arg-info-precedence arg-info)
1663                  (compute-precedence lambda-list nreq
1664                                      argument-precedence-order)))
1665         (esetf (arg-info-metatypes arg-info) (make-list nreq))
1666         (esetf (arg-info-number-optional arg-info) nopt)
1667         (esetf (arg-info-key/rest-p arg-info) (not (null (or keysp restp))))
1668         (esetf (arg-info-keys arg-info)
1669                (if lambda-list-p
1670                    (if allow-other-keys-p t keywords)
1671                    (arg-info-key/rest-p arg-info)))))
1672     (when new-method
1673       (check-method-arg-info gf arg-info new-method))
1674     (set-arg-info1 gf arg-info new-method methods was-valid-p first-p)
1675     arg-info))
1676
1677 (defun check-method-arg-info (gf arg-info method)
1678   (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1679       (analyze-lambda-list (if (consp method)
1680                                (early-method-lambda-list method)
1681                                (method-lambda-list method)))
1682     (flet ((lose (string &rest args)
1683              (error 'simple-program-error
1684                     :format-control "~@<attempt to add the method~2I~_~S~I~_~
1685                                      to the generic function~2I~_~S;~I~_~
1686                                      but ~?~:>"
1687                     :format-arguments (list method gf string args)))
1688            (comparison-description (x y)
1689              (if (> x y) "more" "fewer")))
1690       (let ((gf-nreq (arg-info-number-required arg-info))
1691             (gf-nopt (arg-info-number-optional arg-info))
1692             (gf-key/rest-p (arg-info-key/rest-p arg-info))
1693             (gf-keywords (arg-info-keys arg-info)))
1694         (unless (= nreq gf-nreq)
1695           (lose
1696            "the method has ~A required arguments than the generic function."
1697            (comparison-description nreq gf-nreq)))
1698         (unless (= nopt gf-nopt)
1699           (lose
1700            "the method has ~A optional arguments than the generic function."
1701            (comparison-description nopt gf-nopt)))
1702         (unless (eq (or keysp restp) gf-key/rest-p)
1703           (lose
1704            "the method and generic function differ in whether they accept~_~
1705             &REST or &KEY arguments."))
1706         (when (consp gf-keywords)
1707           (unless (or (and restp (not keysp))
1708                       allow-other-keys-p
1709                       (every (lambda (k) (memq k keywords)) gf-keywords))
1710             (lose "the method does not accept each of the &KEY arguments~2I~_~
1711                    ~S."
1712                   gf-keywords)))))))
1713
1714 (defun set-arg-info1 (gf arg-info new-method methods was-valid-p first-p)
1715   (let* ((existing-p (and methods (cdr methods) new-method))
1716          (nreq (length (arg-info-metatypes arg-info)))
1717          (metatypes (if existing-p
1718                         (arg-info-metatypes arg-info)
1719                         (make-list nreq)))
1720          (type (if existing-p
1721                    (gf-info-simple-accessor-type arg-info)
1722                    nil)))
1723     (when (arg-info-valid-p arg-info)
1724       (dolist (method (if new-method (list new-method) methods))
1725         (let* ((specializers (if (or (eq *boot-state* 'complete)
1726                                      (not (consp method)))
1727                                  (method-specializers method)
1728                                  (early-method-specializers method t)))
1729                (class (if (or (eq *boot-state* 'complete) (not (consp method)))
1730                           (class-of method)
1731                           (early-method-class method)))
1732                (new-type (when (and class
1733                                     (or (not (eq *boot-state* 'complete))
1734                                         (eq (generic-function-method-combination gf)
1735                                             *standard-method-combination*)))
1736                            (cond ((eq class *the-class-standard-reader-method*)
1737                                   'reader)
1738                                  ((eq class *the-class-standard-writer-method*)
1739                                   'writer)
1740                                  ((eq class *the-class-standard-boundp-method*)
1741                                   'boundp)))))
1742           (setq metatypes (mapcar #'raise-metatype metatypes specializers))
1743           (setq type (cond ((null type) new-type)
1744                            ((eq type new-type) type)
1745                            (t nil)))))
1746       (esetf (arg-info-metatypes arg-info) metatypes)
1747       (esetf (gf-info-simple-accessor-type arg-info) type)))
1748   (when (or (not was-valid-p) first-p)
1749     (multiple-value-bind (c-a-m-emf std-p)
1750         (if (early-gf-p gf)
1751             (values t t)
1752             (compute-applicable-methods-emf gf))
1753       (esetf (gf-info-static-c-a-m-emf arg-info) c-a-m-emf)
1754       (esetf (gf-info-c-a-m-emf-std-p arg-info) std-p)
1755       (unless (gf-info-c-a-m-emf-std-p arg-info)
1756         (esetf (gf-info-simple-accessor-type arg-info) t))))
1757   (unless was-valid-p
1758     (let ((name (if (eq *boot-state* 'complete)
1759                     (generic-function-name gf)
1760                     (!early-gf-name gf))))
1761       (esetf (gf-precompute-dfun-and-emf-p arg-info)
1762              (cond
1763                ((and (consp name)
1764                      (member (car name)
1765                              *internal-pcl-generalized-fun-name-symbols*))
1766                 nil)
1767                (t (let* ((symbol (fun-name-block-name name))
1768                          (package (symbol-package symbol)))
1769                     (and (or (eq package *pcl-package*)
1770                              (memq package (package-use-list *pcl-package*)))
1771                          ;; FIXME: this test will eventually be
1772                          ;; superseded by the *internal-pcl...* test,
1773                          ;; above.  While we are in a process of
1774                          ;; transition, however, it should probably
1775                          ;; remain.
1776                          (not (find #\Space (symbol-name symbol))))))))))
1777   (esetf (gf-info-fast-mf-p arg-info)
1778          (or (not (eq *boot-state* 'complete))
1779              (let* ((method-class (generic-function-method-class gf))
1780                     (methods (compute-applicable-methods
1781                               #'make-method-lambda
1782                               (list gf (class-prototype method-class)
1783                                     '(lambda) nil))))
1784                (and methods (null (cdr methods))
1785                     (let ((specls (method-specializers (car methods))))
1786                       (and (classp (car specls))
1787                            (eq 'standard-generic-function
1788                                (class-name (car specls)))
1789                            (classp (cadr specls))
1790                            (eq 'standard-method
1791                                (class-name (cadr specls)))))))))
1792   arg-info)
1793
1794 ;;; This is the early definition of ENSURE-GENERIC-FUNCTION-USING-CLASS.
1795 ;;;
1796 ;;; The STATIC-SLOTS field of the funcallable instances used as early
1797 ;;; generic functions is used to store the early methods and early
1798 ;;; discriminator code for the early generic function. The static
1799 ;;; slots field of the fins contains a list whose:
1800 ;;;    CAR    -   a list of the early methods on this early gf
1801 ;;;    CADR   -   the early discriminator code for this method
1802 (defun ensure-generic-function-using-class (existing spec &rest keys
1803                                             &key (lambda-list nil
1804                                                               lambda-list-p)
1805                                             argument-precedence-order
1806                                             &allow-other-keys)
1807   (declare (ignore keys))
1808   (cond ((and existing (early-gf-p existing))
1809          (when lambda-list-p
1810            (set-arg-info existing :lambda-list lambda-list))
1811          existing)
1812         ((assoc spec *!generic-function-fixups* :test #'equal)
1813          (if existing
1814              (make-early-gf spec lambda-list lambda-list-p existing
1815                             argument-precedence-order)
1816              (error "The function ~S is not already defined." spec)))
1817         (existing
1818          (error "~S should be on the list ~S."
1819                 spec
1820                 '*!generic-function-fixups*))
1821         (t
1822          (pushnew spec *!early-generic-functions* :test #'equal)
1823          (make-early-gf spec lambda-list lambda-list-p nil
1824                         argument-precedence-order))))
1825
1826 (defun make-early-gf (spec &optional lambda-list lambda-list-p
1827                       function argument-precedence-order)
1828   (let ((fin (allocate-funcallable-instance *sgf-wrapper* *sgf-slots-init*)))
1829     (set-funcallable-instance-function
1830      fin
1831      (or function
1832          (if (eq spec 'print-object)
1833              #'(instance-lambda (instance stream)
1834                  (print-unreadable-object (instance stream :identity t)
1835                    (format stream "std-instance")))
1836              #'(instance-lambda (&rest args)
1837                  (declare (ignore args))
1838                  (error "The function of the funcallable-instance ~S~
1839                          has not been set." fin)))))
1840     (setf (gdefinition spec) fin)
1841     (!bootstrap-set-slot 'standard-generic-function fin 'name spec)
1842     (!bootstrap-set-slot 'standard-generic-function
1843                          fin
1844                          'source
1845                          *load-pathname*)
1846     (set-fun-name fin spec)
1847     (let ((arg-info (make-arg-info)))
1848       (setf (early-gf-arg-info fin) arg-info)
1849       (when lambda-list-p
1850         (proclaim (defgeneric-declaration spec lambda-list))
1851         (if argument-precedence-order
1852             (set-arg-info fin
1853                           :lambda-list lambda-list
1854                           :argument-precedence-order argument-precedence-order)
1855             (set-arg-info fin :lambda-list lambda-list))))
1856     fin))
1857
1858 (defun set-dfun (gf &optional dfun cache info)
1859   (when cache
1860     (setf (cache-owner cache) gf))
1861   (let ((new-state (if (and dfun (or cache info))
1862                        (list* dfun cache info)
1863                        dfun)))
1864     (if (eq *boot-state* 'complete)
1865         (setf (gf-dfun-state gf) new-state)
1866         (setf (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*)
1867               new-state)))
1868   dfun)
1869
1870 (defun gf-dfun-cache (gf)
1871   (let ((state (if (eq *boot-state* 'complete)
1872                    (gf-dfun-state gf)
1873                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1874     (typecase state
1875       (function nil)
1876       (cons (cadr state)))))
1877
1878 (defun gf-dfun-info (gf)
1879   (let ((state (if (eq *boot-state* 'complete)
1880                    (gf-dfun-state gf)
1881                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1882     (typecase state
1883       (function nil)
1884       (cons (cddr state)))))
1885
1886 (defvar *sgf-name-index*
1887   (!bootstrap-slot-index 'standard-generic-function 'name))
1888
1889 (defun !early-gf-name (gf)
1890   (clos-slots-ref (get-slots gf) *sgf-name-index*))
1891
1892 (defun gf-lambda-list (gf)
1893   (let ((arg-info (if (eq *boot-state* 'complete)
1894                       (gf-arg-info gf)
1895                       (early-gf-arg-info gf))))
1896     (if (eq :no-lambda-list (arg-info-lambda-list arg-info))
1897         (let ((methods (if (eq *boot-state* 'complete)
1898                            (generic-function-methods gf)
1899                            (early-gf-methods gf))))
1900           (if (null methods)
1901               (progn
1902                 (warn "no way to determine the lambda list for ~S" gf)
1903                 nil)
1904               (let* ((method (car (last methods)))
1905                      (ll (if (consp method)
1906                              (early-method-lambda-list method)
1907                              (method-lambda-list method)))
1908                      (k (member '&key ll)))
1909                 (if k
1910                     (ldiff ll (cdr k))
1911                     ll))))
1912         (arg-info-lambda-list arg-info))))
1913
1914 (defmacro real-ensure-gf-internal (gf-class all-keys env)
1915   `(progn
1916      (cond ((symbolp ,gf-class)
1917             (setq ,gf-class (find-class ,gf-class t ,env)))
1918            ((classp ,gf-class))
1919            (t
1920             (error "The :GENERIC-FUNCTION-CLASS argument (~S) was neither a~%~
1921                     class nor a symbol that names a class."
1922                    ,gf-class)))
1923      (remf ,all-keys :generic-function-class)
1924      (remf ,all-keys :environment)
1925      (let ((combin (getf ,all-keys :method-combination '.shes-not-there.)))
1926        (unless (eq combin '.shes-not-there.)
1927          (setf (getf ,all-keys :method-combination)
1928                (find-method-combination (class-prototype ,gf-class)
1929                                         (car combin)
1930                                         (cdr combin)))))
1931     (let ((method-class (getf ,all-keys :method-class '.shes-not-there.)))
1932       (unless (eq method-class '.shes-not-there.)
1933         (setf (getf ,all-keys :method-class)
1934                 (find-class method-class t ,env))))))
1935
1936 (defun real-ensure-gf-using-class--generic-function
1937        (existing
1938         fun-name
1939         &rest all-keys
1940         &key environment (lambda-list nil lambda-list-p)
1941              (generic-function-class 'standard-generic-function gf-class-p)
1942         &allow-other-keys)
1943   (real-ensure-gf-internal generic-function-class all-keys environment)
1944   (unless (or (null gf-class-p)
1945               (eq (class-of existing) generic-function-class))
1946     (change-class existing generic-function-class))
1947   (prog1
1948       (apply #'reinitialize-instance existing all-keys)
1949     (when lambda-list-p
1950       (proclaim (defgeneric-declaration fun-name lambda-list)))))
1951
1952 (defun real-ensure-gf-using-class--null
1953        (existing
1954         fun-name
1955         &rest all-keys
1956         &key environment (lambda-list nil lambda-list-p)
1957              (generic-function-class 'standard-generic-function)
1958         &allow-other-keys)
1959   (declare (ignore existing))
1960   (real-ensure-gf-internal generic-function-class all-keys environment)
1961   (prog1
1962       (setf (gdefinition fun-name)
1963             (apply #'make-instance generic-function-class
1964                    :name fun-name all-keys))
1965     (when lambda-list-p
1966       (proclaim (defgeneric-declaration fun-name lambda-list)))))
1967 \f
1968 (defun get-generic-fun-info (gf)
1969   ;; values   nreq applyp metatypes nkeys arg-info
1970   (multiple-value-bind (applyp metatypes arg-info)
1971       (let* ((arg-info (if (early-gf-p gf)
1972                            (early-gf-arg-info gf)
1973                            (gf-arg-info gf)))
1974              (metatypes (arg-info-metatypes arg-info)))
1975         (values (arg-info-applyp arg-info)
1976                 metatypes
1977                 arg-info))
1978     (values (length metatypes) applyp metatypes
1979             (count-if (lambda (x) (neq x t)) metatypes)
1980             arg-info)))
1981
1982 (defun early-make-a-method (class qualifiers arglist specializers initargs doc
1983                             &optional slot-name)
1984   (initialize-method-function initargs)
1985   (let ((parsed ())
1986         (unparsed ()))
1987     ;; Figure out whether we got class objects or class names as the
1988     ;; specializers and set parsed and unparsed appropriately. If we
1989     ;; got class objects, then we can compute unparsed, but if we got
1990     ;; class names we don't try to compute parsed.
1991     ;;
1992     ;; Note that the use of not symbolp in this call to every should be
1993     ;; read as 'classp' we can't use classp itself because it doesn't
1994     ;; exist yet.
1995     (if (every (lambda (s) (not (symbolp s))) specializers)
1996         (setq parsed specializers
1997               unparsed (mapcar (lambda (s)
1998                                  (if (eq s t) t (class-name s)))
1999                                specializers))
2000         (setq unparsed specializers
2001               parsed ()))
2002     (list :early-method           ;This is an early method dammit!
2003
2004           (getf initargs :function)
2005           (getf initargs :fast-function)
2006
2007           parsed                  ;The parsed specializers. This is used
2008                                   ;by early-method-specializers to cache
2009                                   ;the parse. Note that this only comes
2010                                   ;into play when there is more than one
2011                                   ;early method on an early gf.
2012
2013           (list class        ;A list to which real-make-a-method
2014                 qualifiers      ;can be applied to make a real method
2015                 arglist    ;corresponding to this early one.
2016                 unparsed
2017                 initargs
2018                 doc
2019                 slot-name))))
2020
2021 (defun real-make-a-method
2022        (class qualifiers lambda-list specializers initargs doc
2023         &optional slot-name)
2024   (setq specializers (parse-specializers specializers))
2025   (apply #'make-instance class
2026          :qualifiers qualifiers
2027          :lambda-list lambda-list
2028          :specializers specializers
2029          :documentation doc
2030          :slot-name slot-name
2031          :allow-other-keys t
2032          initargs))
2033
2034 (defun early-method-function (early-method)
2035   (values (cadr early-method) (caddr early-method)))
2036
2037 (defun early-method-class (early-method)
2038   (find-class (car (fifth early-method))))
2039
2040 (defun early-method-standard-accessor-p (early-method)
2041   (let ((class (first (fifth early-method))))
2042     (or (eq class 'standard-reader-method)
2043         (eq class 'standard-writer-method)
2044         (eq class 'standard-boundp-method))))
2045
2046 (defun early-method-standard-accessor-slot-name (early-method)
2047   (seventh (fifth early-method)))
2048
2049 ;;; Fetch the specializers of an early method. This is basically just
2050 ;;; a simple accessor except that when the second argument is t, this
2051 ;;; converts the specializers from symbols into class objects. The
2052 ;;; class objects are cached in the early method, this makes
2053 ;;; bootstrapping faster because the class objects only have to be
2054 ;;; computed once.
2055 ;;;
2056 ;;; NOTE:
2057 ;;;  The second argument should only be passed as T by
2058 ;;;  early-lookup-method. This is to implement the rule that only when
2059 ;;;  there is more than one early method on a generic function is the
2060 ;;;  conversion from class names to class objects done. This
2061 ;;;  corresponds to the fact that we are only allowed to have one
2062 ;;;  method on any generic function up until the time classes exist.
2063 (defun early-method-specializers (early-method &optional objectsp)
2064   (if (and (listp early-method)
2065            (eq (car early-method) :early-method))
2066       (cond ((eq objectsp t)
2067              (or (fourth early-method)
2068                  (setf (fourth early-method)
2069                        (mapcar #'find-class (cadddr (fifth early-method))))))
2070             (t
2071              (cadddr (fifth early-method))))
2072       (error "~S is not an early-method." early-method)))
2073
2074 (defun early-method-qualifiers (early-method)
2075   (cadr (fifth early-method)))
2076
2077 (defun early-method-lambda-list (early-method)
2078   (caddr (fifth early-method)))
2079
2080 (defun early-add-named-method (generic-function-name
2081                                qualifiers
2082                                specializers
2083                                arglist
2084                                &rest initargs)
2085   (let* ((gf (ensure-generic-function generic-function-name))
2086          (existing
2087            (dolist (m (early-gf-methods gf))
2088              (when (and (equal (early-method-specializers m) specializers)
2089                         (equal (early-method-qualifiers m) qualifiers))
2090                (return m))))
2091          (new (make-a-method 'standard-method
2092                              qualifiers
2093                              arglist
2094                              specializers
2095                              initargs
2096                              ())))
2097     (when existing (remove-method gf existing))
2098     (add-method gf new)))
2099
2100 ;;; This is the early version of ADD-METHOD. Later this will become a
2101 ;;; generic function. See !FIX-EARLY-GENERIC-FUNCTIONS which has
2102 ;;; special knowledge about ADD-METHOD.
2103 (defun add-method (generic-function method)
2104   (when (not (fsc-instance-p generic-function))
2105     (error "Early ADD-METHOD didn't get a funcallable instance."))
2106   (when (not (and (listp method) (eq (car method) :early-method)))
2107     (error "Early ADD-METHOD didn't get an early method."))
2108   (push method (early-gf-methods generic-function))
2109   (set-arg-info generic-function :new-method method)
2110   (unless (assoc (!early-gf-name generic-function)
2111                  *!generic-function-fixups*
2112                  :test #'equal)
2113     (update-dfun generic-function)))
2114
2115 ;;; This is the early version of REMOVE-METHOD. See comments on
2116 ;;; the early version of ADD-METHOD.
2117 (defun remove-method (generic-function method)
2118   (when (not (fsc-instance-p generic-function))
2119     (error "An early remove-method didn't get a funcallable instance."))
2120   (when (not (and (listp method) (eq (car method) :early-method)))
2121     (error "An early remove-method didn't get an early method."))
2122   (setf (early-gf-methods generic-function)
2123         (remove method (early-gf-methods generic-function)))
2124   (set-arg-info generic-function)
2125   (unless (assoc (!early-gf-name generic-function)
2126                  *!generic-function-fixups*
2127                  :test #'equal)
2128     (update-dfun generic-function)))
2129
2130 ;;; This is the early version of GET-METHOD. See comments on the early
2131 ;;; version of ADD-METHOD.
2132 (defun get-method (generic-function qualifiers specializers
2133                                     &optional (errorp t))
2134   (if (early-gf-p generic-function)
2135       (or (dolist (m (early-gf-methods generic-function))
2136             (when (and (or (equal (early-method-specializers m nil)
2137                                   specializers)
2138                            (equal (early-method-specializers m t)
2139                                   specializers))
2140                        (equal (early-method-qualifiers m) qualifiers))
2141               (return m)))
2142           (if errorp
2143               (error "can't get early method")
2144               nil))
2145       (real-get-method generic-function qualifiers specializers errorp)))
2146
2147 (defun !fix-early-generic-functions ()
2148   (let ((accessors nil))
2149     ;; Rearrange *!EARLY-GENERIC-FUNCTIONS* to speed up
2150     ;; FIX-EARLY-GENERIC-FUNCTIONS.
2151     (dolist (early-gf-spec *!early-generic-functions*)
2152       (when (every #'early-method-standard-accessor-p
2153                    (early-gf-methods (gdefinition early-gf-spec)))
2154         (push early-gf-spec accessors)))
2155     (dolist (spec (nconc accessors
2156                          '(accessor-method-slot-name
2157                            generic-function-methods
2158                            method-specializers
2159                            specializerp
2160                            specializer-type
2161                            specializer-class
2162                            slot-definition-location
2163                            slot-definition-name
2164                            class-slots
2165                            gf-arg-info
2166                            class-precedence-list
2167                            slot-boundp-using-class
2168                            (setf slot-value-using-class)
2169                            slot-value-using-class
2170                            structure-class-p
2171                            standard-class-p
2172                            funcallable-standard-class-p
2173                            specializerp)))
2174       (/show spec)
2175       (setq *!early-generic-functions*
2176             (cons spec
2177                   (delete spec *!early-generic-functions* :test #'equal))))
2178
2179     (dolist (early-gf-spec *!early-generic-functions*)
2180       (/show early-gf-spec)
2181       (let* ((gf (gdefinition early-gf-spec))
2182              (methods (mapcar (lambda (early-method)
2183                                 (let ((args (copy-list (fifth
2184                                                         early-method))))
2185                                   (setf (fourth args)
2186                                         (early-method-specializers
2187                                          early-method t))
2188                                   (apply #'real-make-a-method args)))
2189                               (early-gf-methods gf))))
2190         (setf (generic-function-method-class gf) *the-class-standard-method*)
2191         (setf (generic-function-method-combination gf)
2192               *standard-method-combination*)
2193         (set-methods gf methods)))
2194
2195     (dolist (fn *!early-functions*)
2196       (/show fn)
2197       (setf (gdefinition (car fn)) (fdefinition (caddr fn))))
2198
2199     (dolist (fixup *!generic-function-fixups*)
2200       (/show fixup)
2201       (let* ((fspec (car fixup))
2202              (gf (gdefinition fspec))
2203              (methods (mapcar (lambda (method)
2204                                 (let* ((lambda-list (first method))
2205                                        (specializers (second method))
2206                                        (method-fn-name (third method))
2207                                        (fn-name (or method-fn-name fspec))
2208                                        (fn (fdefinition fn-name))
2209                                        (initargs
2210                                         (list :function
2211                                               (set-fun-name
2212                                                (lambda (args next-methods)
2213                                                  (declare (ignore
2214                                                            next-methods))
2215                                                  (apply fn args))
2216                                                `(call ,fn-name)))))
2217                                   (declare (type function fn))
2218                                   (make-a-method 'standard-method
2219                                                  ()
2220                                                  lambda-list
2221                                                  specializers
2222                                                  initargs
2223                                                  nil)))
2224                               (cdr fixup))))
2225         (setf (generic-function-method-class gf) *the-class-standard-method*)
2226         (setf (generic-function-method-combination gf)
2227               *standard-method-combination*)
2228         (set-methods gf methods))))
2229   (/show "leaving !FIX-EARLY-GENERIC-FUNCTIONS"))
2230 \f
2231 ;;; PARSE-DEFMETHOD is used by DEFMETHOD to parse the &REST argument
2232 ;;; into the 'real' arguments. This is where the syntax of DEFMETHOD
2233 ;;; is really implemented.
2234 (defun parse-defmethod (cdr-of-form)
2235   (declare (list cdr-of-form))
2236   (let ((name (pop cdr-of-form))
2237         (qualifiers ())
2238         (spec-ll ()))
2239     (loop (if (and (car cdr-of-form) (atom (car cdr-of-form)))
2240               (push (pop cdr-of-form) qualifiers)
2241               (return (setq qualifiers (nreverse qualifiers)))))
2242     (setq spec-ll (pop cdr-of-form))
2243     (values name qualifiers spec-ll cdr-of-form)))
2244
2245 (defun parse-specializers (specializers)
2246   (declare (list specializers))
2247   (flet ((parse (spec)
2248            (let ((result (specializer-from-type spec)))
2249              (if (specializerp result)
2250                  result
2251                  (if (symbolp spec)
2252                      (error "~S was used as a specializer,~%~
2253                              but is not the name of a class."
2254                             spec)
2255                      (error "~S is not a legal specializer." spec))))))
2256     (mapcar #'parse specializers)))
2257
2258 (defun unparse-specializers (specializers-or-method)
2259   (if (listp specializers-or-method)
2260       (flet ((unparse (spec)
2261                (if (specializerp spec)
2262                    (let ((type (specializer-type spec)))
2263                      (if (and (consp type)
2264                               (eq (car type) 'class))
2265                          (let* ((class (cadr type))
2266                                 (class-name (class-name class)))
2267                            (if (eq class (find-class class-name nil))
2268                                class-name
2269                                type))
2270                          type))
2271                    (error "~S is not a legal specializer." spec))))
2272         (mapcar #'unparse specializers-or-method))
2273       (unparse-specializers (method-specializers specializers-or-method))))
2274
2275 (defun parse-method-or-spec (spec &optional (errorp t))
2276   (let (gf method name temp)
2277     (if (method-p spec)
2278         (setq method spec
2279               gf (method-generic-function method)
2280               temp (and gf (generic-function-name gf))
2281               name (if temp
2282                        (intern-fun-name
2283                          (make-method-spec temp
2284                                            (method-qualifiers method)
2285                                            (unparse-specializers
2286                                              (method-specializers method))))
2287                        (make-symbol (format nil "~S" method))))
2288         (multiple-value-bind (gf-spec quals specls)
2289             (parse-defmethod spec)
2290           (and (setq gf (and (or errorp (gboundp gf-spec))
2291                              (gdefinition gf-spec)))
2292                (let ((nreq (compute-discriminating-function-arglist-info gf)))
2293                  (setq specls (append (parse-specializers specls)
2294                                       (make-list (- nreq (length specls))
2295                                                  :initial-element
2296                                                  *the-class-t*)))
2297                  (and
2298                    (setq method (get-method gf quals specls errorp))
2299                    (setq name
2300                          (intern-fun-name (make-method-spec gf-spec
2301                                                             quals
2302                                                             specls))))))))
2303     (values gf method name)))
2304 \f
2305 (defun extract-parameters (specialized-lambda-list)
2306   (multiple-value-bind (parameters ignore1 ignore2)
2307       (parse-specialized-lambda-list specialized-lambda-list)
2308     (declare (ignore ignore1 ignore2))
2309     parameters))
2310
2311 (defun extract-lambda-list (specialized-lambda-list)
2312   (multiple-value-bind (ignore1 lambda-list ignore2)
2313       (parse-specialized-lambda-list specialized-lambda-list)
2314     (declare (ignore ignore1 ignore2))
2315     lambda-list))
2316
2317 (defun extract-specializer-names (specialized-lambda-list)
2318   (multiple-value-bind (ignore1 ignore2 specializers)
2319       (parse-specialized-lambda-list specialized-lambda-list)
2320     (declare (ignore ignore1 ignore2))
2321     specializers))
2322
2323 (defun extract-required-parameters (specialized-lambda-list)
2324   (multiple-value-bind (ignore1 ignore2 ignore3 required-parameters)
2325       (parse-specialized-lambda-list specialized-lambda-list)
2326     (declare (ignore ignore1 ignore2 ignore3))
2327     required-parameters))
2328
2329 (defun parse-specialized-lambda-list
2330     (arglist
2331      &optional supplied-keywords (allowed-keywords '(&optional &rest &key &aux))
2332      &aux (specialized-lambda-list-keywords
2333            '(&optional &rest &key &allow-other-keys &aux)))
2334   (let ((arg (car arglist)))
2335     (cond ((null arglist) (values nil nil nil nil))
2336           ((eq arg '&aux)
2337            (values nil arglist nil nil))
2338           ((memq arg lambda-list-keywords)
2339            ;; Now, since we try to conform to ANSI, non-standard
2340            ;; lambda-list-keywords should be treated as errors.
2341            (unless (memq arg specialized-lambda-list-keywords)
2342              (error 'simple-program-error
2343                     :format-control "unknown specialized-lambda-list ~
2344                                      keyword ~S~%"
2345                     :format-arguments (list arg)))
2346            ;; no multiple &rest x &rest bla specifying
2347            (when (memq arg supplied-keywords)
2348              (error 'simple-program-error
2349                     :format-control "multiple occurrence of ~
2350                                      specialized-lambda-list keyword ~S~%"
2351                     :format-arguments (list arg)))
2352            ;; And no placing &key in front of &optional, either.
2353            (unless (memq arg allowed-keywords)
2354              (error 'simple-program-error
2355                     :format-control "misplaced specialized-lambda-list ~
2356                                      keyword ~S~%"
2357                     :format-arguments (list arg)))
2358            ;; When we are at a lambda-list keyword, the parameters
2359            ;; don't include the lambda-list keyword; the lambda-list
2360            ;; does include the lambda-list keyword; and no
2361            ;; specializers are allowed to follow the lambda-list
2362            ;; keywords (at least for now).
2363            (multiple-value-bind (parameters lambda-list)
2364                (parse-specialized-lambda-list (cdr arglist)
2365                                               (cons arg supplied-keywords)
2366                                               (if (eq arg '&key)
2367                                                   (cons '&allow-other-keys
2368                                                         (cdr (member arg allowed-keywords)))
2369                                                 (cdr (member arg allowed-keywords))))
2370              (when (and (eq arg '&rest)
2371                         (or (null lambda-list)
2372                             (memq (car lambda-list)
2373                                   specialized-lambda-list-keywords)
2374                             (not (or (null (cadr lambda-list))
2375                                      (memq (cadr lambda-list)
2376                                            specialized-lambda-list-keywords)))))
2377                (error 'simple-program-error
2378                       :format-control
2379                       "in a specialized-lambda-list, excactly one ~
2380                        variable must follow &REST.~%"
2381                       :format-arguments nil))
2382              (values parameters
2383                      (cons arg lambda-list)
2384                      ()
2385                      ())))
2386           (supplied-keywords
2387            ;; After a lambda-list keyword there can be no specializers.
2388            (multiple-value-bind (parameters lambda-list)
2389                (parse-specialized-lambda-list (cdr arglist)
2390                                               supplied-keywords
2391                                               allowed-keywords)
2392              (values (cons (if (listp arg) (car arg) arg) parameters)
2393                      (cons arg lambda-list)
2394                      ()
2395                      ())))
2396           (t
2397            (multiple-value-bind (parameters lambda-list specializers required)
2398                (parse-specialized-lambda-list (cdr arglist))
2399              (values (cons (if (listp arg) (car arg) arg) parameters)
2400                      (cons (if (listp arg) (car arg) arg) lambda-list)
2401                      (cons (if (listp arg) (cadr arg) t) specializers)
2402                      (cons (if (listp arg) (car arg) arg) required)))))))
2403 \f
2404 (setq *boot-state* 'early)
2405 \f
2406 ;;; FIXME: In here there was a #-CMU definition of SYMBOL-MACROLET
2407 ;;; which used %WALKER stuff. That suggests to me that maybe the code
2408 ;;; walker stuff was only used for implementing stuff like that; maybe
2409 ;;; it's not needed any more? Hunt down what it was used for and see.
2410
2411 (defmacro with-slots (slots instance &body body)
2412   (let ((in (gensym)))
2413     `(let ((,in ,instance))
2414        (declare (ignorable ,in))
2415        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2416                              (third instance)
2417                              instance)))
2418            (and (symbolp instance)
2419                 `((declare (%variable-rebinding ,in ,instance)))))
2420        ,in
2421        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2422                                    (let ((var-name
2423                                           (if (symbolp slot-entry)
2424                                               slot-entry
2425                                               (car slot-entry)))
2426                                          (slot-name
2427                                           (if (symbolp slot-entry)
2428                                               slot-entry
2429                                               (cadr slot-entry))))
2430                                      `(,var-name
2431                                        (slot-value ,in ',slot-name))))
2432                                  slots)
2433                         ,@body))))
2434
2435 (defmacro with-accessors (slots instance &body body)
2436   (let ((in (gensym)))
2437     `(let ((,in ,instance))
2438        (declare (ignorable ,in))
2439        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2440                              (third instance)
2441                              instance)))
2442            (and (symbolp instance)
2443                 `((declare (%variable-rebinding ,in ,instance)))))
2444        ,in
2445        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2446                                    (let ((var-name (car slot-entry))
2447                                          (accessor-name (cadr slot-entry)))
2448                                      `(,var-name (,accessor-name ,in))))
2449                                  slots)
2450           ,@body))))