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               ((:argument-precedence-order :method-combination)
 194                (if (initarg car-option)
 195                    (duplicate-option car-option)
 196                    (setf (initarg car-option)
 197                          `',(cdr option))))
 198               ((:documentation :generic-function-class :method-class)
 199                (unless (proper-list-of-length-p option 2)
 200                  (error "bad list length for ~S" option))
 201                (if (initarg car-option)
 202                    (duplicate-option car-option)
 203                    (setf (initarg car-option) `',(cadr option))))
 204               (:method
 205                (push (cdr option) methods))
 206               (t
 207                ;; ANSI requires that unsupported things must get a
 208                ;; PROGRAM-ERROR.
 209                (error 'simple-program-error
 210                       :format-control "unsupported option ~S"
 211                       :format-arguments (list option))))))
 212
 213         (when (initarg :declarations)
 214           (setf (initarg :declarations)
 215                 `',(initarg :declarations))))
 216       `(progn
 217          (eval-when (:compile-toplevel :load-toplevel :execute)
 218            (compile-or-load-defgeneric ',fun-name))
 219          (load-defgeneric ',fun-name ',lambda-list ,@initargs)
 220         ,@(mapcar #'expand-method-definition methods)
 221          #',fun-name))))
 222
 223 (defun compile-or-load-defgeneric (fun-name)
 224   (proclaim-as-fun-name fun-name)
 225   (note-name-defined fun-name :function)
 226   (unless (eq (info :function :where-from fun-name) :declared)
 227     (setf (info :function :where-from fun-name) :defined)
 228     (setf (info :function :type fun-name)
 229           (specifier-type 'function))))
 230
 231 (defun load-defgeneric (fun-name lambda-list &rest initargs)
 232   (when (fboundp fun-name)
 233     (style-warn "redefining ~S in DEFGENERIC" fun-name)
 234     (let ((fun (fdefinition fun-name)))
 235       (when (generic-function-p fun)
 236         (loop for method in (generic-function-initial-methods fun)
 237               do (remove-method fun method))
 238         (setf (generic-function-initial-methods fun) '()))))
 239   (apply #'ensure-generic-function
 240          fun-name
 241          :lambda-list lambda-list
 242          :definition-source `((defgeneric ,fun-name) ,*load-pathname*)
 243          initargs))
 244
 245 ;;; As per section 3.4.2 of the ANSI spec, generic function lambda
 246 ;;; lists have some special limitations, which we check here.
 247 (defun check-gf-lambda-list (lambda-list)
 248   (flet ((ensure (arg ok)
 249            (unless ok
 250              (error
 251               ;; (s/invalid/non-ANSI-conforming/ because the old PCL
 252               ;; implementation allowed this, so people got used to
 253               ;; it, and maybe this phrasing will help them to guess
 254               ;; why their program which worked under PCL no longer works.)
 255               "~@<non-ANSI-conforming argument ~S ~_in the generic function lambda list ~S~:>"
 256               arg lambda-list))))
 257     (multiple-value-bind (required optional restp rest keyp keys allowp
 258                           auxp aux morep more-context more-count)
 259         (parse-lambda-list lambda-list)
 260       (declare (ignore required)) ; since they're no different in a gf ll
 261       (declare (ignore restp rest)) ; since they're no different in a gf ll
 262       (declare (ignore allowp)) ; since &ALLOW-OTHER-KEYS is fine either way
 263       (declare (ignore aux)) ; since we require AUXP=NIL
 264       (declare (ignore more-context more-count)) ; safely ignored unless MOREP
 265       ;; no defaults allowed for &OPTIONAL arguments
 266       (dolist (i optional)
 267         (ensure i (or (symbolp i)
 268                       (and (consp i) (symbolp (car i)) (null (cdr i))))))
 269       ;; no defaults allowed for &KEY arguments
 270       (when keyp
 271         (dolist (i keys)
 272           (ensure i (or (symbolp i)
 273                         (and (consp i)
 274                              (or (symbolp (car i))
 275                                  (and (consp (car i))
 276                                       (symbolp (caar i))
 277                                       (symbolp (cadar i))
 278                                       (null (cddar i))))
 279                              (null (cdr i)))))))
 280       ;; no &AUX allowed
 281       (when auxp
 282         (error "&AUX is not allowed in a generic function lambda list: ~S"
 283                lambda-list))
 284       ;; Oh, *puhlease*... not specifically as per section 3.4.2 of
 285       ;; the ANSI spec, but the CMU CL &MORE extension does not
 286       ;; belong here!
 287       (aver (not morep)))))
 288 \f
 289 (defmacro defmethod (&rest args &environment env)
 290   (multiple-value-bind (name qualifiers lambda-list body)
 291       (parse-defmethod args)
 292     (multiple-value-bind (proto-gf proto-method)
 293         (prototypes-for-make-method-lambda name)
 294       (expand-defmethod name
 295                         proto-gf
 296                         proto-method
 297                         qualifiers
 298                         lambda-list
 299                         body
 300                         env))))
 301
 302 (defun prototypes-for-make-method-lambda (name)
 303   (if (not (eq *boot-state* 'complete))
 304       (values nil nil)
 305       (let ((gf? (and (gboundp name)
 306                       (gdefinition name))))
 307         (if (or (null gf?)
 308                 (not (generic-function-p gf?)))
 309             (values (class-prototype (find-class 'standard-generic-function))
 310                     (class-prototype (find-class 'standard-method)))
 311             (values gf?
 312                     (class-prototype (or (generic-function-method-class gf?)
 313                                          (find-class 'standard-method))))))))
 314
 315 ;;; Take a name which is either a generic function name or a list specifying
 316 ;;; a SETF generic function (like: (SETF <generic-function-name>)). Return
 317 ;;; the prototype instance of the method-class for that generic function.
 318 ;;;
 319 ;;; If there is no generic function by that name, this returns the
 320 ;;; default value, the prototype instance of the class
 321 ;;; STANDARD-METHOD. This default value is also returned if the spec
 322 ;;; names an ordinary function or even a macro. In effect, this leaves
 323 ;;; the signalling of the appropriate error until load time.
 324 ;;;
 325 ;;; Note: During bootstrapping, this function is allowed to return NIL.
 326 (defun method-prototype-for-gf (name)
 327   (let ((gf? (and (gboundp name)
 328                   (gdefinition name))))
 329     (cond ((neq *boot-state* 'complete) nil)
 330           ((or (null gf?)
 331                (not (generic-function-p gf?)))          ; Someone else MIGHT
 332                                                         ; error at load time.
 333            (class-prototype (find-class 'standard-method)))
 334           (t
 335             (class-prototype (or (generic-function-method-class gf?)
 336                                  (find-class 'standard-method)))))))
 337 \f
 338 (defun expand-defmethod (name
 339                          proto-gf
 340                          proto-method
 341                          qualifiers
 342                          lambda-list
 343                          body
 344                          env)
 345   (multiple-value-bind (method-lambda unspecialized-lambda-list specializers)
 346       (add-method-declarations name qualifiers lambda-list body env)
 347     (multiple-value-bind (method-function-lambda initargs)
 348         (make-method-lambda proto-gf proto-method method-lambda env)
 349       (let ((initargs-form (make-method-initargs-form proto-gf
 350                                                       proto-method
 351                                                       method-function-lambda
 352                                                       initargs
 353                                                       env)))
 354         `(progn
 355           ;; Note: We could DECLAIM the ftype of the generic function
 356           ;; here, since ANSI specifies that we create it if it does
 357           ;; not exist. However, I chose not to, because I think it's
 358           ;; more useful to support a style of programming where every
 359           ;; generic function has an explicit DEFGENERIC and any typos
 360           ;; in DEFMETHODs are warned about. Otherwise
 361           ;;
 362           ;;   (DEFGENERIC FOO-BAR-BLETCH ((X T)))
 363           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X HASH-TABLE)) ..)
 364           ;;   (DEFMETHOD FOO-BRA-BLETCH ((X SIMPLE-VECTOR)) ..)
 365           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X VECTOR)) ..)
 366           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X ARRAY)) ..)
 367           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X LIST)) ..)
 368           ;;
 369           ;; compiles without raising an error and runs without
 370           ;; raising an error (since SIMPLE-VECTOR cases fall through
 371           ;; to VECTOR) but still doesn't do what was intended. I hate
 372           ;; that kind of bug (code which silently gives the wrong
 373           ;; answer), so we don't do a DECLAIM here. -- WHN 20000229
 374           ,(make-defmethod-form name qualifiers specializers
 375                                 unspecialized-lambda-list
 376                                 (if proto-method
 377                                     (class-name (class-of proto-method))
 378                                     'standard-method)
 379                                 initargs-form
 380                                 (getf (getf initargs :plist)
 381                                       :pv-table-symbol)))))))
 382
 383 (defun interned-symbol-p (x)
 384   (and (symbolp x) (symbol-package x)))
 385
 386 (defun make-defmethod-form (name qualifiers specializers
 387                                  unspecialized-lambda-list method-class-name
 388                                  initargs-form &optional pv-table-symbol)
 389   (let (fn
 390         fn-lambda)
 391     (if (and (interned-symbol-p (fun-name-block-name name))
 392              (every #'interned-symbol-p qualifiers)
 393              (every (lambda (s)
 394                       (if (consp s)
 395                           (and (eq (car s) 'eql)
 396                                (constantp (cadr s))
 397                                (let ((sv (eval (cadr s))))
 398                                  (or (interned-symbol-p sv)
 399                                      (integerp sv)
 400                                      (and (characterp sv)
 401                                           (standard-char-p sv)))))
 402                           (interned-symbol-p s)))
 403                     specializers)
 404              (consp initargs-form)
 405              (eq (car initargs-form) 'list*)
 406              (memq (cadr initargs-form) '(:function :fast-function))
 407              (consp (setq fn (caddr initargs-form)))
 408              (eq (car fn) 'function)
 409              (consp (setq fn-lambda (cadr fn)))
 410              (eq (car fn-lambda) 'lambda))
 411         (let* ((specls (mapcar (lambda (specl)
 412                                  (if (consp specl)
 413                                      `(,(car specl) ,(eval (cadr specl)))
 414                                    specl))
 415                                specializers))
 416                (mname `(,(if (eq (cadr initargs-form) :function)
 417                              'method 'fast-method)
 418                         ,name ,@qualifiers ,specls))
 419                (mname-sym (intern (let ((*print-pretty* nil)
 420                                         ;; (We bind *PACKAGE* to
 421                                         ;; KEYWORD here as a way to
 422                                         ;; force symbols to be printed
 423                                         ;; with explicit package
 424                                         ;; prefixes.)
 425                                         (*package* *keyword-package*))
 426                                     (format nil "~S" mname)))))
 427           `(progn
 428              (defun ,mname-sym ,(cadr fn-lambda)
 429                ,@(cddr fn-lambda))
 430              ,(make-defmethod-form-internal
 431                name qualifiers `',specls
 432                unspecialized-lambda-list method-class-name
 433                `(list* ,(cadr initargs-form)
 434                        #',mname-sym
 435                        ,@(cdddr initargs-form))
 436                pv-table-symbol)))
 437         (make-defmethod-form-internal
 438          name qualifiers
 439          `(list ,@(mapcar (lambda (specializer)
 440                             (if (consp specializer)
 441                                 ``(,',(car specializer)
 442                                    ,,(cadr specializer))
 443                                 `',specializer))
 444                           specializers))
 445          unspecialized-lambda-list
 446          method-class-name
 447          initargs-form
 448          pv-table-symbol))))
 449
 450 (defun make-defmethod-form-internal
 451     (name qualifiers specializers-form unspecialized-lambda-list
 452      method-class-name initargs-form &optional pv-table-symbol)
 453   `(load-defmethod
 454     ',method-class-name
 455     ',name
 456     ',qualifiers
 457     ,specializers-form
 458     ',unspecialized-lambda-list
 459     ,initargs-form
 460     ;; Paper over a bug in KCL by passing the cache-symbol here in
 461     ;; addition to in the list. FIXME: We should no longer need to do
 462     ;; this, since the CLOS code is now SBCL-specific, and doesn't
 463     ;; need to be ported to every buggy compiler in existence.
 464     ',pv-table-symbol))
 465
 466 (defmacro make-method-function (method-lambda &environment env)
 467   (make-method-function-internal method-lambda env))
 468
 469 (defun make-method-function-internal (method-lambda &optional env)
 470   (multiple-value-bind (proto-gf proto-method)
 471       (prototypes-for-make-method-lambda nil)
 472     (multiple-value-bind (method-function-lambda initargs)
 473         (make-method-lambda proto-gf proto-method method-lambda env)
 474       (make-method-initargs-form proto-gf
 475                                  proto-method
 476                                  method-function-lambda
 477                                  initargs
 478                                  env))))
 479
 480 (defun add-method-declarations (name qualifiers lambda-list body env)
 481   (multiple-value-bind (parameters unspecialized-lambda-list specializers)
 482       (parse-specialized-lambda-list lambda-list)
 483     (declare (ignore parameters))
 484     (multiple-value-bind (real-body declarations documentation)
 485         (parse-body body env)
 486       (values `(lambda ,unspecialized-lambda-list
 487                  ,@(when documentation `(,documentation))
 488                  ;; (Old PCL code used a somewhat different style of
 489                  ;; list for %METHOD-NAME values. Our names use
 490                  ;; ,@QUALIFIERS instead of ,QUALIFIERS so that the
 491                  ;; method names look more like what you see in a
 492                  ;; DEFMETHOD form.)
 493                  ;;
 494                  ;; FIXME: As of sbcl-0.7.0.6, code elsewhere, at
 495                  ;; least the code to set up named BLOCKs around the
 496                  ;; bodies of methods, depends on the function's base
 497                  ;; name being the first element of the %METHOD-NAME
 498                  ;; list. It would be good to remove this dependency,
 499                  ;; perhaps by building the BLOCK here, or by using
 500                  ;; another declaration (e.g. %BLOCK-NAME), so that
 501                  ;; our method debug names are free to have any format,
 502                  ;; e.g. (:METHOD PRINT-OBJECT :AROUND (CLOWN T)).
 503                  ;;
 504                  ;; Further, as of sbcl-0.7.9.10, the code to
 505                  ;; implement NO-NEXT-METHOD is coupled to the form of
 506                  ;; this declaration; see the definition of
 507                  ;; CALL-NO-NEXT-METHOD (and the passing of
 508                  ;; METHOD-NAME-DECLARATION arguments around the
 509                  ;; various CALL-NEXT-METHOD logic).
 510                  (declare (%method-name (,name
 511                                          ,@qualifiers
 512                                          ,specializers)))
 513                  (declare (%method-lambda-list ,@lambda-list))
 514                  ,@declarations
 515                  ,@real-body)
 516               unspecialized-lambda-list specializers))))
 517
 518 (defun real-make-method-initargs-form (proto-gf proto-method
 519                                        method-lambda initargs env)
 520   (declare (ignore proto-gf proto-method))
 521   (unless (and (consp method-lambda)
 522                (eq (car method-lambda) 'lambda))
 523     (error "The METHOD-LAMBDA argument to MAKE-METHOD-FUNCTION, ~S, ~
 524             is not a lambda form."
 525            method-lambda))
 526   (make-method-initargs-form-internal method-lambda initargs env))
 527
 528 (unless (fboundp 'make-method-initargs-form)
 529   (setf (gdefinition 'make-method-initargs-form)
 530         (symbol-function 'real-make-method-initargs-form)))
 531
 532 (defun real-make-method-lambda (proto-gf proto-method method-lambda env)
 533   (declare (ignore proto-gf proto-method))
 534   (make-method-lambda-internal method-lambda env))
 535
 536 ;;; a helper function for creating Python-friendly type declarations
 537 ;;; in DEFMETHOD forms
 538 (defun parameter-specializer-declaration-in-defmethod (parameter specializer)
 539   (cond ((and (consp specializer)
 540               (eq (car specializer) 'eql))
 541          ;; KLUDGE: ANSI, in its wisdom, says that
 542          ;; EQL-SPECIALIZER-FORMs in EQL specializers are evaluated at
 543          ;; DEFMETHOD expansion time. Thus, although one might think
 544          ;; that in
 545          ;;   (DEFMETHOD FOO ((X PACKAGE)
 546          ;;                   (Y (EQL 12))
 547          ;;      ..))
 548          ;; the PACKAGE and (EQL 12) forms are both parallel type
 549          ;; names, they're not, as is made clear when you do
 550          ;;   (DEFMETHOD FOO ((X PACKAGE)
 551          ;;                   (Y (EQL 'BAR)))
 552          ;;     ..)
 553          ;; where Y needs to be a symbol named "BAR", not some cons
 554          ;; made by (CONS 'QUOTE 'BAR). I.e. when the
 555          ;; EQL-SPECIALIZER-FORM is (EQL 'X), it requires an argument
 556          ;; to be of type (EQL X). It'd be easy to transform one to
 557          ;; the other, but it'd be somewhat messier to do so while
 558          ;; ensuring that the EQL-SPECIALIZER-FORM is only EVAL'd
 559          ;; once. (The new code wouldn't be messy, but it'd require a
 560          ;; big transformation of the old code.) So instead we punt.
 561          ;; -- WHN 20000610
 562          '(ignorable))
 563         ((member specializer
 564                  ;; KLUDGE: For some low-level implementation
 565                  ;; classes, perhaps because of some problems related
 566                  ;; to the incomplete integration of PCL into SBCL's
 567                  ;; type system, some specializer classes can't be
 568                  ;; declared as argument types. E.g.
 569                  ;;   (DEFMETHOD FOO ((X SLOT-OBJECT))
 570                  ;;     (DECLARE (TYPE SLOT-OBJECT X))
 571                  ;;     ..)
 572                  ;; loses when
 573                  ;;   (DEFSTRUCT BAR A B)
 574                  ;;   (FOO (MAKE-BAR))
 575                  ;; perhaps because of the way that STRUCTURE-OBJECT
 576                  ;; inherits both from SLOT-OBJECT and from
 577                  ;; SB-KERNEL:INSTANCE. In an effort to sweep such
 578                  ;; problems under the rug, we exclude these problem
 579                  ;; cases by blacklisting them here. -- WHN 2001-01-19
 580                  '(slot-object))
 581          '(ignorable))
 582         ((not (eq *boot-state* 'complete))
 583          ;; KLUDGE: PCL, in its wisdom, sometimes calls methods with
 584          ;; types which don't match their specializers. (Specifically,
 585          ;; it calls ENSURE-CLASS-USING-CLASS (T NULL) with a non-NULL
 586          ;; second argument.) Hopefully it only does this kind of
 587          ;; weirdness when bootstrapping.. -- WHN 20000610
 588          '(ignorable))
 589         (t
 590          ;; Otherwise, we can usually make Python very happy.
 591          (let ((type (info :type :kind specializer)))
 592            (ecase type
 593              ((:primitive :defined :instance :forthcoming-defclass-type)
 594               `(type ,specializer ,parameter))
 595              ((nil)
 596               (let ((class (find-class specializer nil)))
 597                 (if class
 598                     `(type ,(class-name class) ,parameter)
 599                     (progn
 600                       ;; we can get here, and still not have a failure
 601                       ;; case, by doing MOP programming like (PROGN
 602                       ;; (ENSURE-CLASS 'FOO) (DEFMETHOD BAR ((X FOO))
 603                       ;; ...)).  Best to let the user know we haven't
 604                       ;; been able to extract enough information:
 605                       (style-warn
 606                        "~@<can't find type for presumed class ~S in ~S.~@:>"
 607                        specializer
 608                        'parameter-specializer-declaration-in-defmethod)
 609                       '(ignorable))))))))))
 610
 611 (defun make-method-lambda-internal (method-lambda &optional env)
 612   (unless (and (consp method-lambda) (eq (car method-lambda) 'lambda))
 613     (error "The METHOD-LAMBDA argument to MAKE-METHOD-LAMBDA, ~S, ~
 614             is not a lambda form."
 615            method-lambda))
 616   (multiple-value-bind (real-body declarations documentation)
 617       (parse-body (cddr method-lambda) env)
 618     (let* ((name-decl (get-declaration '%method-name declarations))
 619            (sll-decl (get-declaration '%method-lambda-list declarations))
 620            (method-name (when (consp name-decl) (car name-decl)))
 621            (generic-function-name (when method-name (car method-name)))
 622            (specialized-lambda-list (or sll-decl (cadr method-lambda))))
 623       (multiple-value-bind (parameters lambda-list specializers)
 624           (parse-specialized-lambda-list specialized-lambda-list)
 625         (let* ((required-parameters
 626                 (mapcar (lambda (r s) (declare (ignore s)) r)
 627                         parameters
 628                         specializers))
 629                (slots (mapcar #'list required-parameters))
 630                (calls (list nil))
 631                (class-declarations
 632                 `(declare
 633                   ;; These declarations seem to be used by PCL to pass
 634                   ;; information to itself; when I tried to delete 'em
 635                   ;; ca. 0.6.10 it didn't work. I'm not sure how
 636                   ;; they work, but note the (VAR-DECLARATION '%CLASS ..)
 637                   ;; expression in CAN-OPTIMIZE-ACCESS1. -- WHN 2000-12-30
 638                   ,@(remove nil
 639                             (mapcar (lambda (a s) (and (symbolp s)
 640                                                        (neq s t)
 641                                                        `(%class ,a ,s)))
 642                                     parameters
 643                                     specializers))
 644                   ;; These TYPE declarations weren't in the original
 645                   ;; PCL code, but the Python compiler likes them a
 646                   ;; lot. (We're telling the compiler about our
 647                   ;; knowledge of specialized argument types so that
 648                   ;; it can avoid run-time type dispatch overhead,
 649                   ;; which can be a huge win for Python.)
 650                   ;;
 651                   ;; FIXME: Perhaps these belong in
 652                   ;; ADD-METHOD-DECLARATIONS instead of here?
 653                   ,@(mapcar #'parameter-specializer-declaration-in-defmethod
 654                             parameters
 655                             specializers)))
 656                (method-lambda
 657                 ;; Remove the documentation string and insert the
 658                 ;; appropriate class declarations. The documentation
 659                 ;; string is removed to make it easy for us to insert
 660                 ;; new declarations later, they will just go after the
 661                 ;; CADR of the method lambda. The class declarations
 662                 ;; are inserted to communicate the class of the method's
 663                 ;; arguments to the code walk.
 664                 `(lambda ,lambda-list
 665                    ;; The default ignorability of method parameters
 666                    ;; doesn't seem to be specified by ANSI. PCL had
 667                    ;; them basically ignorable but was a little
 668                    ;; inconsistent. E.g. even though the two
 669                    ;; method definitions
 670                    ;;   (DEFMETHOD FOO ((X T) (Y T)) "Z")
 671                    ;;   (DEFMETHOD FOO ((X T) Y) "Z")
 672                    ;; are otherwise equivalent, PCL treated Y as
 673                    ;; ignorable in the first definition but not in the
 674                    ;; second definition. We make all required
 675                    ;; parameters ignorable as a way of systematizing
 676                    ;; the old PCL behavior. -- WHN 2000-11-24
 677                    (declare (ignorable ,@required-parameters))
 678                    ,class-declarations
 679                    ,@declarations
 680                    (block ,(fun-name-block-name generic-function-name)
 681                      ,@real-body)))
 682                (constant-value-p (and (null (cdr real-body))
 683                                       (constantp (car real-body))))
 684                (constant-value (and constant-value-p
 685                                     (eval (car real-body))))
 686                (plist (and constant-value-p
 687                            (or (typep constant-value
 688                                       '(or number character))
 689                                (and (symbolp constant-value)
 690                                     (symbol-package constant-value)))
 691                            (list :constant-value constant-value)))
 692                (applyp (dolist (p lambda-list nil)
 693                          (cond ((memq p '(&optional &rest &key))
 694                                 (return t))
 695                                ((eq p '&aux)
 696                                 (return nil))))))
 697           (multiple-value-bind
 698               (walked-lambda call-next-method-p closurep next-method-p-p)
 699               (walk-method-lambda method-lambda
 700                                   required-parameters
 701                                   env
 702                                   slots
 703                                   calls)
 704             (multiple-value-bind (walked-lambda-body
 705                                   walked-declarations
 706                                   walked-documentation)
 707                 (parse-body (cddr walked-lambda) env)
 708               (declare (ignore walked-documentation))
 709               (when (or next-method-p-p call-next-method-p)
 710                 (setq plist (list* :needs-next-methods-p t plist)))
 711               (when (some #'cdr slots)
 712                 (multiple-value-bind (slot-name-lists call-list)
 713                     (slot-name-lists-from-slots slots calls)
 714                   (let ((pv-table-symbol (make-symbol "pv-table")))
 715                     (setq plist
 716                           `(,@(when slot-name-lists
 717                                 `(:slot-name-lists ,slot-name-lists))
 718                               ,@(when call-list
 719                                   `(:call-list ,call-list))
 720                               :pv-table-symbol ,pv-table-symbol
 721                               ,@plist))
 722                     (setq walked-lambda-body
 723                           `((pv-binding (,required-parameters
 724                                          ,slot-name-lists
 725                                          ,pv-table-symbol)
 726                                         ,@walked-lambda-body))))))
 727               (when (and (memq '&key lambda-list)
 728                          (not (memq '&allow-other-keys lambda-list)))
 729                 (let ((aux (memq '&aux lambda-list)))
 730                 (setq lambda-list (nconc (ldiff lambda-list aux)
 731                                          (list '&allow-other-keys)
 732                                          aux))))
 733               (values `(lambda (.method-args. .next-methods.)
 734                          (simple-lexical-method-functions
 735                           (,lambda-list .method-args. .next-methods.
 736                                         :call-next-method-p
 737                                         ,call-next-method-p
 738                                         :next-method-p-p ,next-method-p-p
 739                                         ;; we need to pass this along
 740                                         ;; so that NO-NEXT-METHOD can
 741                                         ;; be given a suitable METHOD
 742                                         ;; argument; we need the
 743                                         ;; QUALIFIERS and SPECIALIZERS
 744                                         ;; inside the declaration to
 745                                         ;; give to FIND-METHOD.
 746                                         :method-name-declaration ,name-decl
 747                                         :closurep ,closurep
 748                                         :applyp ,applyp)
 749                           ,@walked-declarations
 750                           ,@walked-lambda-body))
 751                       `(,@(when plist
 752                       `(:plist ,plist))
 753                           ,@(when documentation
 754                           `(:documentation ,documentation)))))))))))
 755
 756 (unless (fboundp 'make-method-lambda)
 757   (setf (gdefinition 'make-method-lambda)
 758         (symbol-function 'real-make-method-lambda)))
 759
 760 (defmacro simple-lexical-method-functions ((lambda-list
 761                                             method-args
 762                                             next-methods
 763                                             &rest lmf-options)
 764                                            &body body)
 765   `(progn
 766      ,method-args ,next-methods
 767      (bind-simple-lexical-method-macros (,method-args ,next-methods)
 768        (bind-lexical-method-functions (,@lmf-options)
 769          (bind-args (,lambda-list ,method-args)
 770            ,@body)))))
 771
 772 (defmacro fast-lexical-method-functions ((lambda-list
 773                                           next-method-call
 774                                           args
 775                                           rest-arg
 776                                           &rest lmf-options)
 777                                          &body body)
 778   `(bind-fast-lexical-method-macros (,args ,rest-arg ,next-method-call)
 779      (bind-lexical-method-functions (,@lmf-options)
 780        (bind-args (,(nthcdr (length args) lambda-list) ,rest-arg)
 781          ,@body))))
 782
 783 (defmacro bind-simple-lexical-method-macros ((method-args next-methods)
 784                                              &body body)
 785   `(macrolet ((call-next-method-bind (&body body)
 786                 `(let ((.next-method. (car ,',next-methods))
 787                        (,',next-methods (cdr ,',next-methods)))
 788                    .next-method. ,',next-methods
 789                    ,@body))
 790               (call-next-method-body (method-name-declaration cnm-args)
 791                 `(if .next-method.
 792                      (funcall (if (std-instance-p .next-method.)
 793                                   (method-function .next-method.)
 794                                   .next-method.) ; for early methods
 795                               (or ,cnm-args ,',method-args)
 796                               ,',next-methods)
 797                      (apply #'call-no-next-method ',method-name-declaration
 798                             (or ,cnm-args ,',method-args))))
 799               (next-method-p-body ()
 800                 `(not (null .next-method.))))
 801      ,@body))
 802
 803 (defun call-no-next-method (method-name-declaration &rest args)
 804   (destructuring-bind (name) method-name-declaration
 805     (destructuring-bind (name &rest qualifiers-and-specializers) name
 806       ;; KLUDGE: inefficient traversal, but hey.  This should only
 807       ;; happen on the slow error path anyway.
 808       (let* ((qualifiers (butlast qualifiers-and-specializers))
 809              (specializers (car (last qualifiers-and-specializers)))
 810              (method (find-method (gdefinition name) qualifiers specializers)))
 811         (apply #'no-next-method
 812                (method-generic-function method)
 813                method
 814                args)))))
 815
 816 (defstruct (method-call (:copier nil))
 817   (function #'identity :type function)
 818   call-method-args)
 819
 820 #-sb-fluid (declaim (sb-ext:freeze-type method-call))
 821
 822 (defmacro invoke-method-call1 (function args cm-args)
 823   `(let ((.function. ,function)
 824          (.args. ,args)
 825          (.cm-args. ,cm-args))
 826      (if (and .cm-args. (null (cdr .cm-args.)))
 827          (funcall .function. .args. (car .cm-args.))
 828          (apply .function. .args. .cm-args.))))
 829
 830 (defmacro invoke-method-call (method-call restp &rest required-args+rest-arg)
 831   `(invoke-method-call1 (method-call-function ,method-call)
 832                         ,(if restp
 833                              `(list* ,@required-args+rest-arg)
 834                              `(list ,@required-args+rest-arg))
 835                         (method-call-call-method-args ,method-call)))
 836
 837 (defstruct (fast-method-call (:copier nil))
 838   (function #'identity :type function)
 839   pv-cell
 840   next-method-call
 841   arg-info)
 842
 843 #-sb-fluid (declaim (sb-ext:freeze-type fast-method-call))
 844
 845 (defmacro fmc-funcall (fn pv-cell next-method-call &rest args)
 846   `(funcall ,fn ,pv-cell ,next-method-call ,@args))
 847
 848 (defmacro invoke-fast-method-call (method-call &rest required-args+rest-arg)
 849   `(fmc-funcall (fast-method-call-function ,method-call)
 850                 (fast-method-call-pv-cell ,method-call)
 851                 (fast-method-call-next-method-call ,method-call)
 852                 ,@required-args+rest-arg))
 853
 854 (defstruct (fast-instance-boundp (:copier nil))
 855   (index 0 :type fixnum))
 856
 857 #-sb-fluid (declaim (sb-ext:freeze-type fast-instance-boundp))
 858
 859 (eval-when (:compile-toplevel :load-toplevel :execute)
 860   (defvar *allow-emf-call-tracing-p* nil)
 861   (defvar *enable-emf-call-tracing-p* #-sb-show nil #+sb-show t))
 862 \f
 863 ;;;; effective method functions
 864
 865 (defvar *emf-call-trace-size* 200)
 866 (defvar *emf-call-trace* nil)
 867 (defvar *emf-call-trace-index* 0)
 868
 869 ;;; This function was in the CMU CL version of PCL (ca Debian 2.4.8)
 870 ;;; without explanation. It appears to be intended for debugging, so
 871 ;;; it might be useful someday, so I haven't deleted it.
 872 ;;; But it isn't documented and isn't used for anything now, so
 873 ;;; I've conditionalized it out of the base system. -- WHN 19991213
 874 #+sb-show
 875 (defun show-emf-call-trace ()
 876   (when *emf-call-trace*
 877     (let ((j *emf-call-trace-index*)
 878           (*enable-emf-call-tracing-p* nil))
 879       (format t "~&(The oldest entries are printed first)~%")
 880       (dotimes-fixnum (i *emf-call-trace-size*)
 881         (let ((ct (aref *emf-call-trace* j)))
 882           (when ct (print ct)))
 883         (incf j)
 884         (when (= j *emf-call-trace-size*)
 885           (setq j 0))))))
 886
 887 (defun trace-emf-call-internal (emf format args)
 888   (unless *emf-call-trace*
 889     (setq *emf-call-trace* (make-array *emf-call-trace-size*)))
 890   (setf (aref *emf-call-trace* *emf-call-trace-index*)
 891         (list* emf format args))
 892   (incf *emf-call-trace-index*)
 893   (when (= *emf-call-trace-index* *emf-call-trace-size*)
 894     (setq *emf-call-trace-index* 0)))
 895
 896 (defmacro trace-emf-call (emf format args)
 897   (when *allow-emf-call-tracing-p*
 898     `(when *enable-emf-call-tracing-p*
 899        (trace-emf-call-internal ,emf ,format ,args))))
 900
 901 (defmacro invoke-effective-method-function-fast
 902     (emf restp &rest required-args+rest-arg)
 903   `(progn
 904      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 905      (invoke-fast-method-call ,emf ,@required-args+rest-arg)))
 906
 907 (defmacro invoke-effective-method-function (emf restp
 908                                                 &rest required-args+rest-arg)
 909   (unless (constantp restp)
 910     (error "The RESTP argument is not constant."))
 911   ;; FIXME: The RESTP handling here is confusing and maybe slightly
 912   ;; broken if RESTP evaluates to a non-self-evaluating form. E.g. if
 913   ;;   (INVOKE-EFFECTIVE-METHOD-FUNCTION EMF '(ERROR "gotcha") ...)
 914   ;; then TRACE-EMF-CALL-CALL-INTERNAL might die on a gotcha error.
 915   (setq restp (eval restp))
 916   `(progn
 917      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 918      (cond ((typep ,emf 'fast-method-call)
 919             (invoke-fast-method-call ,emf ,@required-args+rest-arg))
 920            ;; "What," you may wonder, "do these next two clauses do?"
 921            ;; In that case, you are not a PCL implementor, for they
 922            ;; considered this to be self-documenting.:-| Or CSR, for
 923            ;; that matter, since he can also figure it out by looking
 924            ;; at it without breaking stride. For the rest of us,
 925            ;; though: From what the code is doing with .SLOTS. and
 926            ;; whatnot, evidently it's implementing SLOT-VALUEish and
 927            ;; GET-SLOT-VALUEish things. Then we can reason backwards
 928            ;; and conclude that setting EMF to a FIXNUM is an
 929            ;; optimized way to represent these slot access operations.
 930            ,@(when (and (null restp) (= 1 (length required-args+rest-arg)))
 931                `(((typep ,emf 'fixnum)
 932                   (let* ((.slots. (get-slots-or-nil
 933                                    ,(car required-args+rest-arg)))
 934                          (value (when .slots. (clos-slots-ref .slots. ,emf))))
 935                     (if (eq value +slot-unbound+)
 936                         (slot-unbound-internal ,(car required-args+rest-arg)
 937                                                ,emf)
 938                         value)))))
 939            ,@(when (and (null restp) (= 2 (length required-args+rest-arg)))
 940                `(((typep ,emf 'fixnum)
 941                   (let ((.new-value. ,(car required-args+rest-arg))
 942                         (.slots. (get-slots-or-nil
 943                                   ,(cadr required-args+rest-arg))))
 944                     (when .slots.
 945                       (setf (clos-slots-ref .slots. ,emf) .new-value.))))))
 946            ;; (In cmucl-2.4.8 there was a commented-out third ,@(WHEN
 947            ;; ...) clause here to handle SLOT-BOUNDish stuff. Since
 948            ;; there was no explanation and presumably the code is 10+
 949            ;; years stale, I simply deleted it. -- WHN)
 950            (t
 951             (etypecase ,emf
 952               (method-call
 953                (invoke-method-call ,emf ,restp ,@required-args+rest-arg))
 954               (function
 955                ,(if restp
 956                     `(apply (the function ,emf) ,@required-args+rest-arg)
 957                     `(funcall (the function ,emf)
 958                               ,@required-args+rest-arg))))))))
 959
 960 (defun invoke-emf (emf args)
 961   (trace-emf-call emf t args)
 962   (etypecase emf
 963     (fast-method-call
 964      (let* ((arg-info (fast-method-call-arg-info emf))
 965             (restp (cdr arg-info))
 966             (nreq (car arg-info)))
 967        (if restp
 968            (let* ((rest-args (nthcdr nreq args))
 969                   (req-args (ldiff args rest-args)))
 970              (apply (fast-method-call-function emf)
 971                     (fast-method-call-pv-cell emf)
 972                     (fast-method-call-next-method-call emf)
 973                     (nconc req-args (list rest-args))))
 974            (cond ((null args)
 975                   (if (eql nreq 0)
 976                       (invoke-fast-method-call emf)
 977                       (error "wrong number of args")))
 978                  ((null (cdr args))
 979                   (if (eql nreq 1)
 980                       (invoke-fast-method-call emf (car args))
 981                       (error "wrong number of args")))
 982                  ((null (cddr args))
 983                   (if (eql nreq 2)
 984                       (invoke-fast-method-call emf (car args) (cadr args))
 985                       (error "wrong number of args")))
 986                  (t
 987                   (apply (fast-method-call-function emf)
 988                          (fast-method-call-pv-cell emf)
 989                          (fast-method-call-next-method-call emf)
 990                          args))))))
 991     (method-call
 992      (apply (method-call-function emf)
 993             args
 994             (method-call-call-method-args emf)))
 995     (fixnum
 996      (cond ((null args) (error "1 or 2 args were expected."))
 997            ((null (cdr args))
 998             (let* ((slots (get-slots (car args)))
 999                    (value (clos-slots-ref slots emf)))
1000               (if (eq value +slot-unbound+)
1001                   (slot-unbound-internal (car args) emf)
1002                   value)))
1003            ((null (cddr args))
1004              (setf (clos-slots-ref (get-slots (cadr args)) emf)
1005                    (car args)))
1006            (t (error "1 or 2 args were expected."))))
1007     (fast-instance-boundp
1008      (if (or (null args) (cdr args))
1009          (error "1 arg was expected.")
1010        (let ((slots (get-slots (car args))))
1011          (not (eq (clos-slots-ref slots
1012                                   (fast-instance-boundp-index emf))
1013                   +slot-unbound+)))))
1014     (function
1015      (apply emf args))))
1016 \f
1017 (defmacro bind-fast-lexical-method-macros ((args rest-arg next-method-call)
1018                                            &body body)
1019   `(macrolet ((narrowed-emf (emf)
1020                 ;; INVOKE-EFFECTIVE-METHOD-FUNCTION has code in it to
1021                 ;; dispatch on the possibility that EMF might be of
1022                 ;; type FIXNUM (as an optimized representation of a
1023                 ;; slot accessor). But as far as I (WHN 2002-06-11)
1024                 ;; can tell, it's impossible for such a representation
1025                 ;; to end up as .NEXT-METHOD-CALL. By reassuring
1026                 ;; INVOKE-E-M-F that when called from this context
1027                 ;; it needn't worry about the FIXNUM case, we can
1028                 ;; keep those cases from being compiled, which is
1029                 ;; good both because it saves bytes and because it
1030                 ;; avoids annoying type mismatch compiler warnings.
1031                 ;;
1032                 ;; KLUDGE: In sbcl-0.7.4.29, the compiler's type
1033                 ;; system isn't smart enough about NOT and intersection
1034                 ;; types to benefit from a (NOT FIXNUM) declaration
1035                 ;; here. -- WHN 2002-06-12
1036                 ;;
1037                 ;; FIXME: Might the FUNCTION type be omittable here,
1038                 ;; leaving only METHOD-CALLs? Failing that, could this
1039                 ;; be documented somehow? (It'd be nice if the types
1040                 ;; involved could be understood without solving the
1041                 ;; halting problem.)
1042                 `(the (or function method-call fast-method-call)
1043                    ,emf))
1044               (call-next-method-bind (&body body)
1045                `(let () ,@body))
1046               (call-next-method-body (method-name-declaration cnm-args)
1047                `(if ,',next-method-call
1048                  ,(locally
1049                    ;; This declaration suppresses a "deleting
1050                    ;; unreachable code" note for the following IF when
1051                    ;; REST-ARG is NIL. It is not nice for debugging
1052                    ;; SBCL itself, but at least it keeps us from
1053                    ;; annoying users.
1054                    (declare (optimize (inhibit-warnings 3)))
1055                    (if (and (null ',rest-arg)
1056                             (consp cnm-args)
1057                             (eq (car cnm-args) 'list))
1058                        `(invoke-effective-method-function
1059                          (narrowed-emf ,',next-method-call)
1060                          nil
1061                          ,@(cdr cnm-args))
1062                        (let ((call `(invoke-effective-method-function
1063                                      (narrowed-emf ,',next-method-call)
1064                                      ,',(not (null rest-arg))
1065                                      ,@',args
1066                                      ,@',(when rest-arg `(,rest-arg)))))
1067                          `(if ,cnm-args
1068                            (bind-args ((,@',args
1069                                         ,@',(when rest-arg
1070                                               `(&rest ,rest-arg)))
1071                                        ,cnm-args)
1072                             ,call)
1073                            ,call))))
1074                  ,(locally
1075                    ;; As above, this declaration suppresses code
1076                    ;; deletion notes.
1077                    (declare (optimize (inhibit-warnings 3)))
1078                    (if (and (null ',rest-arg)
1079                             (consp cnm-args)
1080                             (eq (car cnm-args) 'list))
1081                        `(call-no-next-method ',method-name-declaration
1082                                              ,@(cdr cnm-args))
1083                        `(call-no-next-method ',method-name-declaration
1084                                              ,@',args
1085                                              ,@',(when rest-arg
1086                                                        `(,rest-arg)))))))
1087               (next-method-p-body ()
1088                `(not (null ,',next-method-call))))
1089     ,@body))
1090
1091 (defmacro bind-lexical-method-functions
1092     ((&key call-next-method-p next-method-p-p
1093            closurep applyp method-name-declaration)
1094      &body body)
1095   (cond ((and (null call-next-method-p) (null next-method-p-p)
1096               (null closurep)
1097               (null applyp))
1098          `(let () ,@body))
1099         (t
1100          `(call-next-method-bind
1101             (flet (,@(and call-next-method-p
1102                           `((call-next-method (&rest cnm-args)
1103                              (call-next-method-body
1104                               ,method-name-declaration
1105                               cnm-args))))
1106                    ,@(and next-method-p-p
1107                           '((next-method-p ()
1108                               (next-method-p-body)))))
1109               ,@body)))))
1110
1111 (defmacro bind-args ((lambda-list args) &body body)
1112   (let ((args-tail '.args-tail.)
1113         (key '.key.)
1114         (state 'required))
1115     (flet ((process-var (var)
1116              (if (memq var lambda-list-keywords)
1117                  (progn
1118                    (case var
1119                      (&optional       (setq state 'optional))
1120                      (&key            (setq state 'key))
1121                      (&allow-other-keys)
1122                      (&rest           (setq state 'rest))
1123                      (&aux            (setq state 'aux))
1124                      (otherwise
1125                       (error
1126                        "encountered the non-standard lambda list keyword ~S"
1127                        var)))
1128                    nil)
1129                  (case state
1130                    (required `((,var (pop ,args-tail))))
1131                    (optional (cond ((not (consp var))
1132                                     `((,var (when ,args-tail
1133                                               (pop ,args-tail)))))
1134                                    ((null (cddr var))
1135                                     `((,(car var) (if ,args-tail
1136                                                       (pop ,args-tail)
1137                                                       ,(cadr var)))))
1138                                    (t
1139                                     `((,(caddr var) ,args-tail)
1140                                       (,(car var) (if ,args-tail
1141                                                       (pop ,args-tail)
1142                                                       ,(cadr var)))))))
1143                    (rest `((,var ,args-tail)))
1144                    (key (cond ((not (consp var))
1145                                `((,var (car
1146                                         (get-key-arg-tail ,(keywordicate var)
1147                                                           ,args-tail)))))
1148                               ((null (cddr var))
1149                                (multiple-value-bind (keyword variable)
1150                                    (if (consp (car var))
1151                                        (values (caar var)
1152                                                (cadar var))
1153                                        (values (keywordicate (car var))
1154                                                (car var)))
1155                                  `((,key (get-key-arg-tail ',keyword
1156                                                            ,args-tail))
1157                                    (,variable (if ,key
1158                                                   (car ,key)
1159                                                   ,(cadr var))))))
1160                               (t
1161                                (multiple-value-bind (keyword variable)
1162                                    (if (consp (car var))
1163                                        (values (caar var)
1164                                                (cadar var))
1165                                        (values (keywordicate (car var))
1166                                                (car var)))
1167                                  `((,key (get-key-arg-tail ',keyword
1168                                                            ,args-tail))
1169                                    (,(caddr var) ,key)
1170                                    (,variable (if ,key
1171                                                   (car ,key)
1172                                                   ,(cadr var))))))))
1173                    (aux `(,var))))))
1174       (let ((bindings (mapcan #'process-var lambda-list)))
1175         `(let* ((,args-tail ,args)
1176                 ,@bindings)
1177            (declare (ignorable ,args-tail))
1178            ,@body)))))
1179
1180 (defun get-key-arg-tail (keyword list)
1181   (loop for (key . tail) on list by #'cddr
1182         when (null tail) do
1183           ;; FIXME: Do we want to export this symbol? Or maybe use an
1184           ;; (ERROR 'SIMPLE-PROGRAM-ERROR) form?
1185           (sb-c::%odd-key-args-error)
1186         when (eq key keyword)
1187           return tail))
1188
1189 (defun walk-method-lambda (method-lambda required-parameters env slots calls)
1190   (let ((call-next-method-p nil)   ; flag indicating that CALL-NEXT-METHOD
1191                                    ; should be in the method definition
1192         (closurep nil)             ; flag indicating that #'CALL-NEXT-METHOD
1193                                    ; was seen in the body of a method
1194         (next-method-p-p nil))     ; flag indicating that NEXT-METHOD-P
1195                                    ; should be in the method definition
1196     (flet ((walk-function (form context env)
1197              (cond ((not (eq context :eval)) form)
1198                    ;; FIXME: Jumping to a conclusion from the way it's used
1199                    ;; above, perhaps CONTEXT should be called SITUATION
1200                    ;; (after the term used in the ANSI specification of
1201                    ;; EVAL-WHEN) and given modern ANSI keyword values
1202                    ;; like :LOAD-TOPLEVEL.
1203                    ((not (listp form)) form)
1204                    ((eq (car form) 'call-next-method)
1205                     (setq call-next-method-p t)
1206                     form)
1207                    ((eq (car form) 'next-method-p)
1208                     (setq next-method-p-p t)
1209                     form)
1210                    ((and (eq (car form) 'function)
1211                          (cond ((eq (cadr form) 'call-next-method)
1212                                 (setq call-next-method-p t)
1213                                 (setq closurep t)
1214                                 form)
1215                                ((eq (cadr form) 'next-method-p)
1216                                 (setq next-method-p-p t)
1217                                 (setq closurep t)
1218                                 form)
1219                                (t nil))))
1220                    ((and (memq (car form)
1221                                '(slot-value set-slot-value slot-boundp))
1222                          (constantp (caddr form)))
1223                      (let ((parameter (can-optimize-access form
1224                                                            required-parameters
1225                                                            env)))
1226                       (let ((fun (ecase (car form)
1227                                    (slot-value #'optimize-slot-value)
1228                                    (set-slot-value #'optimize-set-slot-value)
1229                                    (slot-boundp #'optimize-slot-boundp))))
1230                         (funcall fun slots parameter form))))
1231                    ((and (eq (car form) 'apply)
1232                          (consp (cadr form))
1233                          (eq (car (cadr form)) 'function)
1234                          (generic-function-name-p (cadr (cadr form))))
1235                     (optimize-generic-function-call
1236                      form required-parameters env slots calls))
1237                    ((generic-function-name-p (car form))
1238                     (optimize-generic-function-call
1239                      form required-parameters env slots calls))
1240                    (t form))))
1241
1242       (let ((walked-lambda (walk-form method-lambda env #'walk-function)))
1243         (values walked-lambda
1244                 call-next-method-p
1245                 closurep
1246                 next-method-p-p)))))
1247
1248 (defun generic-function-name-p (name)
1249   (and (legal-fun-name-p name)
1250        (gboundp name)
1251        (if (eq *boot-state* 'complete)
1252            (standard-generic-function-p (gdefinition name))
1253            (funcallable-instance-p (gdefinition name)))))
1254 \f
1255 (defvar *method-function-plist* (make-hash-table :test 'eq))
1256 (defvar *mf1* nil)
1257 (defvar *mf1p* nil)
1258 (defvar *mf1cp* nil)
1259 (defvar *mf2* nil)
1260 (defvar *mf2p* nil)
1261 (defvar *mf2cp* nil)
1262
1263 (defun method-function-plist (method-function)
1264   (unless (eq method-function *mf1*)
1265     (rotatef *mf1* *mf2*)
1266     (rotatef *mf1p* *mf2p*)
1267     (rotatef *mf1cp* *mf2cp*))
1268   (unless (or (eq method-function *mf1*) (null *mf1cp*))
1269     (setf (gethash *mf1* *method-function-plist*) *mf1p*))
1270   (unless (eq method-function *mf1*)
1271     (setf *mf1* method-function
1272           *mf1cp* nil
1273           *mf1p* (gethash method-function *method-function-plist*)))
1274   *mf1p*)
1275
1276 (defun (setf method-function-plist)
1277     (val method-function)
1278   (unless (eq method-function *mf1*)
1279     (rotatef *mf1* *mf2*)
1280     (rotatef *mf1cp* *mf2cp*)
1281     (rotatef *mf1p* *mf2p*))
1282   (unless (or (eq method-function *mf1*) (null *mf1cp*))
1283     (setf (gethash *mf1* *method-function-plist*) *mf1p*))
1284   (setf *mf1* method-function
1285         *mf1cp* t
1286         *mf1p* val))
1287
1288 (defun method-function-get (method-function key &optional default)
1289   (getf (method-function-plist method-function) key default))
1290
1291 (defun (setf method-function-get)
1292     (val method-function key)
1293   (setf (getf (method-function-plist method-function) key) val))
1294
1295 (defun method-function-pv-table (method-function)
1296   (method-function-get method-function :pv-table))
1297
1298 (defun method-function-method (method-function)
1299   (method-function-get method-function :method))
1300
1301 (defun method-function-needs-next-methods-p (method-function)
1302   (method-function-get method-function :needs-next-methods-p t))
1303 \f
1304 (defmacro method-function-closure-generator (method-function)
1305   `(method-function-get ,method-function 'closure-generator))
1306
1307 (defun load-defmethod
1308     (class name quals specls ll initargs &optional pv-table-symbol)
1309   (setq initargs (copy-tree initargs))
1310   (let ((method-spec (or (getf initargs :method-spec)
1311                          (make-method-spec name quals specls))))
1312     (setf (getf initargs :method-spec) method-spec)
1313     (load-defmethod-internal class name quals specls
1314                              ll initargs pv-table-symbol)))
1315
1316 (defun load-defmethod-internal
1317     (method-class gf-spec qualifiers specializers lambda-list
1318                   initargs pv-table-symbol)
1319   (when pv-table-symbol
1320     (setf (getf (getf initargs :plist) :pv-table-symbol)
1321           pv-table-symbol))
1322   (when (and (eq *boot-state* 'complete)
1323              (fboundp gf-spec))
1324     (let* ((gf (fdefinition gf-spec))
1325            (method (and (generic-function-p gf)
1326                         (find-method gf
1327                                      qualifiers
1328                                      (parse-specializers specializers)
1329                                      nil))))
1330       (when method
1331         (style-warn "redefining ~S~{ ~S~} ~S in DEFMETHOD"
1332                     gf-spec qualifiers specializers))))
1333   (let ((method (apply #'add-named-method
1334                        gf-spec qualifiers specializers lambda-list
1335                        :definition-source `((defmethod ,gf-spec
1336                                                 ,@qualifiers
1337                                               ,specializers)
1338                                             ,*load-pathname*)
1339                        initargs)))
1340     (unless (or (eq method-class 'standard-method)
1341                 (eq (find-class method-class nil) (class-of method)))
1342       ;; FIXME: should be STYLE-WARNING?
1343       (format *error-output*
1344               "~&At the time the method with qualifiers ~:S and~%~
1345                specializers ~:S on the generic function ~S~%~
1346                was compiled, the method-class for that generic function was~%~
1347                ~S. But, the method class is now ~S, this~%~
1348                may mean that this method was compiled improperly.~%"
1349               qualifiers specializers gf-spec
1350               method-class (class-name (class-of method))))
1351     method))
1352
1353 (defun make-method-spec (gf-spec qualifiers unparsed-specializers)
1354   `(method ,gf-spec ,@qualifiers ,unparsed-specializers))
1355
1356 (defun initialize-method-function (initargs &optional return-function-p method)
1357   (let* ((mf (getf initargs :function))
1358          (method-spec (getf initargs :method-spec))
1359          (plist (getf initargs :plist))
1360          (pv-table-symbol (getf plist :pv-table-symbol))
1361          (pv-table nil)
1362          (mff (getf initargs :fast-function)))
1363     (flet ((set-mf-property (p v)
1364              (when mf
1365                (setf (method-function-get mf p) v))
1366              (when mff
1367                (setf (method-function-get mff p) v))))
1368       (when method-spec
1369         (when mf
1370           (setq mf (set-fun-name mf method-spec)))
1371         (when mff
1372           (let ((name `(,(or (get (car method-spec) 'fast-sym)
1373                              (setf (get (car method-spec) 'fast-sym)
1374                                    ;; KLUDGE: If we're going to be
1375                                    ;; interning private symbols in our
1376                                    ;; a this way, it would be cleanest
1377                                    ;; to use a separate package
1378                                    ;; %PCL-PRIVATE or something, and
1379                                    ;; failing that, to use a special
1380                                    ;; symbol prefix denoting privateness.
1381                                    ;; -- WHN 19991201
1382                                    (intern (format nil "FAST-~A"
1383                                                    (car method-spec))
1384                                            *pcl-package*)))
1385                          ,@(cdr method-spec))))
1386             (set-fun-name mff name)
1387             (unless mf
1388               (set-mf-property :name name)))))
1389       (when plist
1390         (let ((snl (getf plist :slot-name-lists))
1391               (cl (getf plist :call-list)))
1392           (when (or snl cl)
1393             (setq pv-table (intern-pv-table :slot-name-lists snl
1394                                             :call-list cl))
1395             (when pv-table (set pv-table-symbol pv-table))
1396             (set-mf-property :pv-table pv-table)))
1397         (loop (when (null plist) (return nil))
1398               (set-mf-property (pop plist) (pop plist)))
1399         (when method
1400           (set-mf-property :method method))
1401         (when return-function-p
1402           (or mf (method-function-from-fast-function mff)))))))
1403 \f
1404 (defun analyze-lambda-list (lambda-list)
1405   (flet (;; FIXME: Is this redundant with SB-C::MAKE-KEYWORD-FOR-ARG?
1406          (parse-key-arg (arg)
1407            (if (listp arg)
1408                (if (listp (car arg))
1409                    (caar arg)
1410                    (keywordicate (car arg)))
1411                (keywordicate arg))))
1412     (let ((nrequired 0)
1413           (noptional 0)
1414           (keysp nil)
1415           (restp nil)
1416           (nrest 0)
1417           (allow-other-keys-p nil)
1418           (keywords ())
1419           (keyword-parameters ())
1420           (state 'required))
1421       (dolist (x lambda-list)
1422         (if (memq x lambda-list-keywords)
1423             (case x
1424               (&optional         (setq state 'optional))
1425               (&key              (setq keysp t
1426                                        state 'key))
1427               (&allow-other-keys (setq allow-other-keys-p t))
1428               (&rest             (setq restp t
1429                                        state 'rest))
1430               (&aux           (return t))
1431               (otherwise
1432                 (error "encountered the non-standard lambda list keyword ~S"
1433                        x)))
1434             (ecase state
1435               (required  (incf nrequired))
1436               (optional  (incf noptional))
1437               (key       (push (parse-key-arg x) keywords)
1438                          (push x keyword-parameters))
1439               (rest      (incf nrest)))))
1440       (when (and restp (zerop nrest))
1441         (error "Error in lambda-list:~%~
1442                 After &REST, a DEFGENERIC lambda-list ~
1443                 must be followed by at least one variable."))
1444       (values nrequired noptional keysp restp allow-other-keys-p
1445               (reverse keywords)
1446               (reverse keyword-parameters)))))
1447
1448 (defun keyword-spec-name (x)
1449   (let ((key (if (atom x) x (car x))))
1450     (if (atom key)
1451         (keywordicate key)
1452         (car key))))
1453
1454 (defun ftype-declaration-from-lambda-list (lambda-list name)
1455   (multiple-value-bind (nrequired noptional keysp restp allow-other-keys-p
1456                                   keywords keyword-parameters)
1457       (analyze-lambda-list lambda-list)
1458     (declare (ignore keyword-parameters))
1459     (let* ((old (info :function :type name)) ;FIXME:FDOCUMENTATION instead?
1460            (old-ftype (if (fun-type-p old) old nil))
1461            (old-restp (and old-ftype (fun-type-rest old-ftype)))
1462            (old-keys (and old-ftype
1463                           (mapcar #'key-info-name
1464                                   (fun-type-keywords
1465                                    old-ftype))))
1466            (old-keysp (and old-ftype (fun-type-keyp old-ftype)))
1467            (old-allowp (and old-ftype
1468                             (fun-type-allowp old-ftype)))
1469            (keywords (union old-keys (mapcar #'keyword-spec-name keywords))))
1470       `(function ,(append (make-list nrequired :initial-element t)
1471                           (when (plusp noptional)
1472                             (append '(&optional)
1473                                     (make-list noptional :initial-element t)))
1474                           (when (or restp old-restp)
1475                             '(&rest t))
1476                           (when (or keysp old-keysp)
1477                             (append '(&key)
1478                                     (mapcar (lambda (key)
1479                                               `(,key t))
1480                                             keywords)
1481                                     (when (or allow-other-keys-p old-allowp)
1482                                       '(&allow-other-keys)))))
1483                  *))))
1484
1485 (defun defgeneric-declaration (spec lambda-list)
1486   (when (consp spec)
1487     (setq spec (get-setf-fun-name (cadr spec))))
1488   `(ftype ,(ftype-declaration-from-lambda-list lambda-list spec) ,spec))
1489 \f
1490 ;;;; early generic function support
1491
1492 (defvar *!early-generic-functions* ())
1493
1494 (defun ensure-generic-function (fun-name
1495                                 &rest all-keys
1496                                 &key environment
1497                                 &allow-other-keys)
1498   (declare (ignore environment))
1499   (let ((existing (and (gboundp fun-name)
1500                        (gdefinition fun-name))))
1501     (if (and existing
1502              (eq *boot-state* 'complete)
1503              (null (generic-function-p existing)))
1504         (generic-clobbers-function fun-name)
1505         (apply #'ensure-generic-function-using-class
1506                existing fun-name all-keys))))
1507
1508 (defun generic-clobbers-function (fun-name)
1509   (error 'simple-program-error
1510          :format-control "~S already names an ordinary function or a macro."
1511          :format-arguments (list fun-name)))
1512
1513 (defvar *sgf-wrapper*
1514   (boot-make-wrapper (early-class-size 'standard-generic-function)
1515                      'standard-generic-function))
1516
1517 (defvar *sgf-slots-init*
1518   (mapcar (lambda (canonical-slot)
1519             (if (memq (getf canonical-slot :name) '(arg-info source))
1520                 +slot-unbound+
1521                 (let ((initfunction (getf canonical-slot :initfunction)))
1522                   (if initfunction
1523                       (funcall initfunction)
1524                       +slot-unbound+))))
1525           (early-collect-inheritance 'standard-generic-function)))
1526
1527 (defvar *sgf-method-class-index*
1528   (!bootstrap-slot-index 'standard-generic-function 'method-class))
1529
1530 (defun early-gf-p (x)
1531   (and (fsc-instance-p x)
1532        (eq (clos-slots-ref (get-slots x) *sgf-method-class-index*)
1533            +slot-unbound+)))
1534
1535 (defvar *sgf-methods-index*
1536   (!bootstrap-slot-index 'standard-generic-function 'methods))
1537
1538 (defmacro early-gf-methods (gf)
1539   `(clos-slots-ref (get-slots ,gf) *sgf-methods-index*))
1540
1541 (defvar *sgf-arg-info-index*
1542   (!bootstrap-slot-index 'standard-generic-function 'arg-info))
1543
1544 (defmacro early-gf-arg-info (gf)
1545   `(clos-slots-ref (get-slots ,gf) *sgf-arg-info-index*))
1546
1547 (defvar *sgf-dfun-state-index*
1548   (!bootstrap-slot-index 'standard-generic-function 'dfun-state))
1549
1550 (defstruct (arg-info
1551             (:conc-name nil)
1552             (:constructor make-arg-info ())
1553             (:copier nil))
1554   (arg-info-lambda-list :no-lambda-list)
1555   arg-info-precedence
1556   arg-info-metatypes
1557   arg-info-number-optional
1558   arg-info-key/rest-p
1559   arg-info-keys   ;nil        no &KEY or &REST allowed
1560                   ;(k1 k2 ..) Each method must accept these &KEY arguments.
1561                   ;T          must have &KEY or &REST
1562
1563   gf-info-simple-accessor-type ; nil, reader, writer, boundp
1564   (gf-precompute-dfun-and-emf-p nil) ; set by set-arg-info
1565
1566   gf-info-static-c-a-m-emf
1567   (gf-info-c-a-m-emf-std-p t)
1568   gf-info-fast-mf-p)
1569
1570 #-sb-fluid (declaim (sb-ext:freeze-type arg-info))
1571
1572 (defun arg-info-valid-p (arg-info)
1573   (not (null (arg-info-number-optional arg-info))))
1574
1575 (defun arg-info-applyp (arg-info)
1576   (or (plusp (arg-info-number-optional arg-info))
1577       (arg-info-key/rest-p arg-info)))
1578
1579 (defun arg-info-number-required (arg-info)
1580   (length (arg-info-metatypes arg-info)))
1581
1582 (defun arg-info-nkeys (arg-info)
1583   (count-if (lambda (x) (neq x t)) (arg-info-metatypes arg-info)))
1584
1585 ;;; Keep pages clean by not setting if the value is already the same.
1586 (defmacro esetf (pos val)
1587   (with-unique-names (valsym)
1588     `(let ((,valsym ,val))
1589        (unless (equal ,pos ,valsym)
1590          (setf ,pos ,valsym)))))
1591
1592 (defun set-arg-info (gf &key new-method (lambda-list nil lambda-list-p)
1593                         argument-precedence-order)
1594   (let* ((arg-info (if (eq *boot-state* 'complete)
1595                        (gf-arg-info gf)
1596                        (early-gf-arg-info gf)))
1597          (methods (if (eq *boot-state* 'complete)
1598                       (generic-function-methods gf)
1599                       (early-gf-methods gf)))
1600          (was-valid-p (integerp (arg-info-number-optional arg-info)))
1601          (first-p (and new-method (null (cdr methods)))))
1602     (when (and (not lambda-list-p) methods)
1603       (setq lambda-list (gf-lambda-list gf)))
1604     (when (or lambda-list-p
1605               (and first-p
1606                    (eq (arg-info-lambda-list arg-info) :no-lambda-list)))
1607       (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1608           (analyze-lambda-list lambda-list)
1609         (when (and methods (not first-p))
1610           (let ((gf-nreq (arg-info-number-required arg-info))
1611                 (gf-nopt (arg-info-number-optional arg-info))
1612                 (gf-key/rest-p (arg-info-key/rest-p arg-info)))
1613             (unless (and (= nreq gf-nreq)
1614                          (= nopt gf-nopt)
1615                          (eq (or keysp restp) gf-key/rest-p))
1616               (error "The lambda-list ~S is incompatible with ~
1617                      existing methods of ~S."
1618                      lambda-list gf))))
1619         (when lambda-list-p
1620           (esetf (arg-info-lambda-list arg-info) lambda-list))
1621         (when (or lambda-list-p argument-precedence-order
1622                   (null (arg-info-precedence arg-info)))
1623           (esetf (arg-info-precedence arg-info)
1624                  (compute-precedence lambda-list nreq
1625                                      argument-precedence-order)))
1626         (esetf (arg-info-metatypes arg-info) (make-list nreq))
1627         (esetf (arg-info-number-optional arg-info) nopt)
1628         (esetf (arg-info-key/rest-p arg-info) (not (null (or keysp restp))))
1629         (esetf (arg-info-keys arg-info)
1630                (if lambda-list-p
1631                    (if allow-other-keys-p t keywords)
1632                    (arg-info-key/rest-p arg-info)))))
1633     (when new-method
1634       (check-method-arg-info gf arg-info new-method))
1635     (set-arg-info1 gf arg-info new-method methods was-valid-p first-p)
1636     arg-info))
1637
1638 (defun check-method-arg-info (gf arg-info method)
1639   (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1640       (analyze-lambda-list (if (consp method)
1641                                (early-method-lambda-list method)
1642                                (method-lambda-list method)))
1643     (flet ((lose (string &rest args)
1644              (error 'simple-program-error
1645                     :format-control "~@<attempt to add the method~2I~_~S~I~_~
1646                                      to the generic function~2I~_~S;~I~_~
1647                                      but ~?~:>"
1648                     :format-arguments (list method gf string args)))
1649            (comparison-description (x y)
1650              (if (> x y) "more" "fewer")))
1651       (let ((gf-nreq (arg-info-number-required arg-info))
1652             (gf-nopt (arg-info-number-optional arg-info))
1653             (gf-key/rest-p (arg-info-key/rest-p arg-info))
1654             (gf-keywords (arg-info-keys arg-info)))
1655         (unless (= nreq gf-nreq)
1656           (lose
1657            "the method has ~A required arguments than the generic function."
1658            (comparison-description nreq gf-nreq)))
1659         (unless (= nopt gf-nopt)
1660           (lose
1661            "the method has ~A optional arguments than the generic function."
1662            (comparison-description nopt gf-nopt)))
1663         (unless (eq (or keysp restp) gf-key/rest-p)
1664           (lose
1665            "the method and generic function differ in whether they accept~_~
1666             &REST or &KEY arguments."))
1667         (when (consp gf-keywords)
1668           (unless (or (and restp (not keysp))
1669                       allow-other-keys-p
1670                       (every (lambda (k) (memq k keywords)) gf-keywords))
1671             (lose "the method does not accept each of the &KEY arguments~2I~_~
1672                    ~S."
1673                   gf-keywords)))))))
1674
1675 (defun set-arg-info1 (gf arg-info new-method methods was-valid-p first-p)
1676   (let* ((existing-p (and methods (cdr methods) new-method))
1677          (nreq (length (arg-info-metatypes arg-info)))
1678          (metatypes (if existing-p
1679                         (arg-info-metatypes arg-info)
1680                         (make-list nreq)))
1681          (type (if existing-p
1682                    (gf-info-simple-accessor-type arg-info)
1683                    nil)))
1684     (when (arg-info-valid-p arg-info)
1685       (dolist (method (if new-method (list new-method) methods))
1686         (let* ((specializers (if (or (eq *boot-state* 'complete)
1687                                      (not (consp method)))
1688                                  (method-specializers method)
1689                                  (early-method-specializers method t)))
1690                (class (if (or (eq *boot-state* 'complete) (not (consp method)))
1691                           (class-of method)
1692                           (early-method-class method)))
1693                (new-type (when (and class
1694                                     (or (not (eq *boot-state* 'complete))
1695                                         (eq (generic-function-method-combination gf)
1696                                             *standard-method-combination*)))
1697                            (cond ((eq class *the-class-standard-reader-method*)
1698                                   'reader)
1699                                  ((eq class *the-class-standard-writer-method*)
1700                                   'writer)
1701                                  ((eq class *the-class-standard-boundp-method*)
1702                                   'boundp)))))
1703           (setq metatypes (mapcar #'raise-metatype metatypes specializers))
1704           (setq type (cond ((null type) new-type)
1705                            ((eq type new-type) type)
1706                            (t nil)))))
1707       (esetf (arg-info-metatypes arg-info) metatypes)
1708       (esetf (gf-info-simple-accessor-type arg-info) type)))
1709   (when (or (not was-valid-p) first-p)
1710     (multiple-value-bind (c-a-m-emf std-p)
1711         (if (early-gf-p gf)
1712             (values t t)
1713             (compute-applicable-methods-emf gf))
1714       (esetf (gf-info-static-c-a-m-emf arg-info) c-a-m-emf)
1715       (esetf (gf-info-c-a-m-emf-std-p arg-info) std-p)
1716       (unless (gf-info-c-a-m-emf-std-p arg-info)
1717         (esetf (gf-info-simple-accessor-type arg-info) t))))
1718   (unless was-valid-p
1719     (let ((name (if (eq *boot-state* 'complete)
1720                     (generic-function-name gf)
1721                     (!early-gf-name gf))))
1722       (esetf (gf-precompute-dfun-and-emf-p arg-info)
1723              (let* ((sym (if (atom name) name (cadr name)))
1724                     (pkg-list (cons *pcl-package*
1725                                     (package-use-list *pcl-package*))))
1726                ;; FIXME: given the presence of generalized function
1727                ;; names, this test is broken.  A little
1728                ;; reverse-engineering suggests that this was intended
1729                ;; to prevent precompilation of things on some
1730                ;; PCL-internal automatically-constructed functions
1731                ;; like the old "~A~A standard class ~A reader"
1732                ;; functions.  When the CADR of SB-PCL::SLOT-ACCESSOR
1733                ;; generalized functions was *, this test returned T,
1734                ;; not NIL, and an error was signalled in
1735                ;; MAKE-ACCESSOR-TABLE for (DEFUN FOO (X) (SLOT-VALUE X
1736                ;; 'ASLDKJ)).  Whether the right thing to do is to fix
1737                ;; MAKE-ACCESSOR-TABLE so that it can work in the
1738                ;; presence of slot names that have no classes, or to
1739                ;; restore this test to something more obvious, I don't
1740                ;; know.  -- CSR, 2003-02-14
1741                (and sym (symbolp sym)
1742                     (not (null (memq (symbol-package sym) pkg-list)))
1743                     (not (find #\space (symbol-name sym))))))))
1744   (esetf (gf-info-fast-mf-p arg-info)
1745          (or (not (eq *boot-state* 'complete))
1746              (let* ((method-class (generic-function-method-class gf))
1747                     (methods (compute-applicable-methods
1748                               #'make-method-lambda
1749                               (list gf (class-prototype method-class)
1750                                     '(lambda) nil))))
1751                (and methods (null (cdr methods))
1752                     (let ((specls (method-specializers (car methods))))
1753                       (and (classp (car specls))
1754                            (eq 'standard-generic-function
1755                                (class-name (car specls)))
1756                            (classp (cadr specls))
1757                            (eq 'standard-method
1758                                (class-name (cadr specls)))))))))
1759   arg-info)
1760
1761 ;;; This is the early definition of ENSURE-GENERIC-FUNCTION-USING-CLASS.
1762 ;;;
1763 ;;; The STATIC-SLOTS field of the funcallable instances used as early
1764 ;;; generic functions is used to store the early methods and early
1765 ;;; discriminator code for the early generic function. The static
1766 ;;; slots field of the fins contains a list whose:
1767 ;;;    CAR    -   a list of the early methods on this early gf
1768 ;;;    CADR   -   the early discriminator code for this method
1769 (defun ensure-generic-function-using-class (existing spec &rest keys
1770                                             &key (lambda-list nil
1771                                                               lambda-list-p)
1772                                             argument-precedence-order
1773                                             &allow-other-keys)
1774   (declare (ignore keys))
1775   (cond ((and existing (early-gf-p existing))
1776          existing)
1777         ((assoc spec *!generic-function-fixups* :test #'equal)
1778          (if existing
1779              (make-early-gf spec lambda-list lambda-list-p existing
1780                             argument-precedence-order)
1781              (error "The function ~S is not already defined." spec)))
1782         (existing
1783          (error "~S should be on the list ~S."
1784                 spec
1785                 '*!generic-function-fixups*))
1786         (t
1787          (pushnew spec *!early-generic-functions* :test #'equal)
1788          (make-early-gf spec lambda-list lambda-list-p nil
1789                         argument-precedence-order))))
1790
1791 (defun make-early-gf (spec &optional lambda-list lambda-list-p
1792                       function argument-precedence-order)
1793   (let ((fin (allocate-funcallable-instance *sgf-wrapper* *sgf-slots-init*)))
1794     (set-funcallable-instance-function
1795      fin
1796      (or function
1797          (if (eq spec 'print-object)
1798              #'(instance-lambda (instance stream)
1799                  (print-unreadable-object (instance stream :identity t)
1800                    (format stream "std-instance")))
1801              #'(instance-lambda (&rest args)
1802                  (declare (ignore args))
1803                  (error "The function of the funcallable-instance ~S~
1804                          has not been set." fin)))))
1805     (setf (gdefinition spec) fin)
1806     (!bootstrap-set-slot 'standard-generic-function fin 'name spec)
1807     (!bootstrap-set-slot 'standard-generic-function
1808                          fin
1809                          'source
1810                          *load-pathname*)
1811     (set-fun-name fin spec)
1812     (let ((arg-info (make-arg-info)))
1813       (setf (early-gf-arg-info fin) arg-info)
1814       (when lambda-list-p
1815         (proclaim (defgeneric-declaration spec lambda-list))
1816         (if argument-precedence-order
1817             (set-arg-info fin
1818                           :lambda-list lambda-list
1819                           :argument-precedence-order argument-precedence-order)
1820             (set-arg-info fin :lambda-list lambda-list))))
1821     fin))
1822
1823 (defun set-dfun (gf &optional dfun cache info)
1824   (when cache
1825     (setf (cache-owner cache) gf))
1826   (let ((new-state (if (and dfun (or cache info))
1827                        (list* dfun cache info)
1828                        dfun)))
1829     (if (eq *boot-state* 'complete)
1830         (setf (gf-dfun-state gf) new-state)
1831         (setf (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*)
1832               new-state)))
1833   dfun)
1834
1835 (defun gf-dfun-cache (gf)
1836   (let ((state (if (eq *boot-state* 'complete)
1837                    (gf-dfun-state gf)
1838                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1839     (typecase state
1840       (function nil)
1841       (cons (cadr state)))))
1842
1843 (defun gf-dfun-info (gf)
1844   (let ((state (if (eq *boot-state* 'complete)
1845                    (gf-dfun-state gf)
1846                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1847     (typecase state
1848       (function nil)
1849       (cons (cddr state)))))
1850
1851 (defvar *sgf-name-index*
1852   (!bootstrap-slot-index 'standard-generic-function 'name))
1853
1854 (defun !early-gf-name (gf)
1855   (clos-slots-ref (get-slots gf) *sgf-name-index*))
1856
1857 (defun gf-lambda-list (gf)
1858   (let ((arg-info (if (eq *boot-state* 'complete)
1859                       (gf-arg-info gf)
1860                       (early-gf-arg-info gf))))
1861     (if (eq :no-lambda-list (arg-info-lambda-list arg-info))
1862         (let ((methods (if (eq *boot-state* 'complete)
1863                            (generic-function-methods gf)
1864                            (early-gf-methods gf))))
1865           (if (null methods)
1866               (progn
1867                 (warn "no way to determine the lambda list for ~S" gf)
1868                 nil)
1869               (let* ((method (car (last methods)))
1870                      (ll (if (consp method)
1871                              (early-method-lambda-list method)
1872                              (method-lambda-list method)))
1873                      (k (member '&key ll)))
1874                 (if k
1875                     (append (ldiff ll (cdr k)) '(&allow-other-keys))
1876                     ll))))
1877         (arg-info-lambda-list arg-info))))
1878
1879 (defmacro real-ensure-gf-internal (gf-class all-keys env)
1880   `(progn
1881      (cond ((symbolp ,gf-class)
1882             (setq ,gf-class (find-class ,gf-class t ,env)))
1883            ((classp ,gf-class))
1884            (t
1885             (error "The :GENERIC-FUNCTION-CLASS argument (~S) was neither a~%~
1886                     class nor a symbol that names a class."
1887                    ,gf-class)))
1888      (remf ,all-keys :generic-function-class)
1889      (remf ,all-keys :environment)
1890      (let ((combin (getf ,all-keys :method-combination '.shes-not-there.)))
1891        (unless (eq combin '.shes-not-there.)
1892          (setf (getf ,all-keys :method-combination)
1893                (find-method-combination (class-prototype ,gf-class)
1894                                         (car combin)
1895                                         (cdr combin)))))
1896     (let ((method-class (getf ,all-keys :method-class '.shes-not-there.)))
1897       (unless (eq method-class '.shes-not-there.)
1898         (setf (getf ,all-keys :method-class)
1899                 (find-class method-class t ,env))))))
1900
1901 (defun real-ensure-gf-using-class--generic-function
1902        (existing
1903         fun-name
1904         &rest all-keys
1905         &key environment (lambda-list nil lambda-list-p)
1906              (generic-function-class 'standard-generic-function gf-class-p)
1907         &allow-other-keys)
1908   (real-ensure-gf-internal generic-function-class all-keys environment)
1909   (unless (or (null gf-class-p)
1910               (eq (class-of existing) generic-function-class))
1911     (change-class existing generic-function-class))
1912   (prog1
1913       (apply #'reinitialize-instance existing all-keys)
1914     (when lambda-list-p
1915       (proclaim (defgeneric-declaration fun-name lambda-list)))))
1916
1917 (defun real-ensure-gf-using-class--null
1918        (existing
1919         fun-name
1920         &rest all-keys
1921         &key environment (lambda-list nil lambda-list-p)
1922              (generic-function-class 'standard-generic-function)
1923         &allow-other-keys)
1924   (declare (ignore existing))
1925   (real-ensure-gf-internal generic-function-class all-keys environment)
1926   (prog1
1927       (setf (gdefinition fun-name)
1928             (apply #'make-instance generic-function-class
1929                    :name fun-name all-keys))
1930     (when lambda-list-p
1931       (proclaim (defgeneric-declaration fun-name lambda-list)))))
1932 \f
1933 (defun get-generic-fun-info (gf)
1934   ;; values   nreq applyp metatypes nkeys arg-info
1935   (multiple-value-bind (applyp metatypes arg-info)
1936       (let* ((arg-info (if (early-gf-p gf)
1937                            (early-gf-arg-info gf)
1938                            (gf-arg-info gf)))
1939              (metatypes (arg-info-metatypes arg-info)))
1940         (values (arg-info-applyp arg-info)
1941                 metatypes
1942                 arg-info))
1943     (values (length metatypes) applyp metatypes
1944             (count-if (lambda (x) (neq x t)) metatypes)
1945             arg-info)))
1946
1947 (defun early-make-a-method (class qualifiers arglist specializers initargs doc
1948                             &optional slot-name)
1949   (initialize-method-function initargs)
1950   (let ((parsed ())
1951         (unparsed ()))
1952     ;; Figure out whether we got class objects or class names as the
1953     ;; specializers and set parsed and unparsed appropriately. If we
1954     ;; got class objects, then we can compute unparsed, but if we got
1955     ;; class names we don't try to compute parsed.
1956     ;;
1957     ;; Note that the use of not symbolp in this call to every should be
1958     ;; read as 'classp' we can't use classp itself because it doesn't
1959     ;; exist yet.
1960     (if (every (lambda (s) (not (symbolp s))) specializers)
1961         (setq parsed specializers
1962               unparsed (mapcar (lambda (s)
1963                                  (if (eq s t) t (class-name s)))
1964                                specializers))
1965         (setq unparsed specializers
1966               parsed ()))
1967     (list :early-method           ;This is an early method dammit!
1968
1969           (getf initargs :function)
1970           (getf initargs :fast-function)
1971
1972           parsed                  ;The parsed specializers. This is used
1973                                   ;by early-method-specializers to cache
1974                                   ;the parse. Note that this only comes
1975                                   ;into play when there is more than one
1976                                   ;early method on an early gf.
1977
1978           (list class        ;A list to which real-make-a-method
1979                 qualifiers      ;can be applied to make a real method
1980                 arglist    ;corresponding to this early one.
1981                 unparsed
1982                 initargs
1983                 doc
1984                 slot-name))))
1985
1986 (defun real-make-a-method
1987        (class qualifiers lambda-list specializers initargs doc
1988         &optional slot-name)
1989   (setq specializers (parse-specializers specializers))
1990   (apply #'make-instance class
1991          :qualifiers qualifiers
1992          :lambda-list lambda-list
1993          :specializers specializers
1994          :documentation doc
1995          :slot-name slot-name
1996          :allow-other-keys t
1997          initargs))
1998
1999 (defun early-method-function (early-method)
2000   (values (cadr early-method) (caddr early-method)))
2001
2002 (defun early-method-class (early-method)
2003   (find-class (car (fifth early-method))))
2004
2005 (defun early-method-standard-accessor-p (early-method)
2006   (let ((class (first (fifth early-method))))
2007     (or (eq class 'standard-reader-method)
2008         (eq class 'standard-writer-method)
2009         (eq class 'standard-boundp-method))))
2010
2011 (defun early-method-standard-accessor-slot-name (early-method)
2012   (seventh (fifth early-method)))
2013
2014 ;;; Fetch the specializers of an early method. This is basically just
2015 ;;; a simple accessor except that when the second argument is t, this
2016 ;;; converts the specializers from symbols into class objects. The
2017 ;;; class objects are cached in the early method, this makes
2018 ;;; bootstrapping faster because the class objects only have to be
2019 ;;; computed once.
2020 ;;;
2021 ;;; NOTE:
2022 ;;;  The second argument should only be passed as T by
2023 ;;;  early-lookup-method. This is to implement the rule that only when
2024 ;;;  there is more than one early method on a generic function is the
2025 ;;;  conversion from class names to class objects done. This
2026 ;;;  corresponds to the fact that we are only allowed to have one
2027 ;;;  method on any generic function up until the time classes exist.
2028 (defun early-method-specializers (early-method &optional objectsp)
2029   (if (and (listp early-method)
2030            (eq (car early-method) :early-method))
2031       (cond ((eq objectsp t)
2032              (or (fourth early-method)
2033                  (setf (fourth early-method)
2034                        (mapcar #'find-class (cadddr (fifth early-method))))))
2035             (t
2036              (cadddr (fifth early-method))))
2037       (error "~S is not an early-method." early-method)))
2038
2039 (defun early-method-qualifiers (early-method)
2040   (cadr (fifth early-method)))
2041
2042 (defun early-method-lambda-list (early-method)
2043   (caddr (fifth early-method)))
2044
2045 (defun early-add-named-method (generic-function-name
2046                                qualifiers
2047                                specializers
2048                                arglist
2049                                &rest initargs)
2050   (let* ((gf (ensure-generic-function generic-function-name))
2051          (existing
2052            (dolist (m (early-gf-methods gf))
2053              (when (and (equal (early-method-specializers m) specializers)
2054                         (equal (early-method-qualifiers m) qualifiers))
2055                (return m))))
2056          (new (make-a-method 'standard-method
2057                              qualifiers
2058                              arglist
2059                              specializers
2060                              initargs
2061                              ())))
2062     (when existing (remove-method gf existing))
2063     (add-method gf new)))
2064
2065 ;;; This is the early version of ADD-METHOD. Later this will become a
2066 ;;; generic function. See !FIX-EARLY-GENERIC-FUNCTIONS which has
2067 ;;; special knowledge about ADD-METHOD.
2068 (defun add-method (generic-function method)
2069   (when (not (fsc-instance-p generic-function))
2070     (error "Early ADD-METHOD didn't get a funcallable instance."))
2071   (when (not (and (listp method) (eq (car method) :early-method)))
2072     (error "Early ADD-METHOD didn't get an early method."))
2073   (push method (early-gf-methods generic-function))
2074   (set-arg-info generic-function :new-method method)
2075   (unless (assoc (!early-gf-name generic-function)
2076                  *!generic-function-fixups*
2077                  :test #'equal)
2078     (update-dfun generic-function)))
2079
2080 ;;; This is the early version of REMOVE-METHOD. See comments on
2081 ;;; the early version of ADD-METHOD.
2082 (defun remove-method (generic-function method)
2083   (when (not (fsc-instance-p generic-function))
2084     (error "An early remove-method didn't get a funcallable instance."))
2085   (when (not (and (listp method) (eq (car method) :early-method)))
2086     (error "An early remove-method didn't get an early method."))
2087   (setf (early-gf-methods generic-function)
2088         (remove method (early-gf-methods generic-function)))
2089   (set-arg-info generic-function)
2090   (unless (assoc (!early-gf-name generic-function)
2091                  *!generic-function-fixups*
2092                  :test #'equal)
2093     (update-dfun generic-function)))
2094
2095 ;;; This is the early version of GET-METHOD. See comments on the early
2096 ;;; version of ADD-METHOD.
2097 (defun get-method (generic-function qualifiers specializers
2098                                     &optional (errorp t))
2099   (if (early-gf-p generic-function)
2100       (or (dolist (m (early-gf-methods generic-function))
2101             (when (and (or (equal (early-method-specializers m nil)
2102                                   specializers)
2103                            (equal (early-method-specializers m t)
2104                                   specializers))
2105                        (equal (early-method-qualifiers m) qualifiers))
2106               (return m)))
2107           (if errorp
2108               (error "can't get early method")
2109               nil))
2110       (real-get-method generic-function qualifiers specializers errorp)))
2111
2112 (defun !fix-early-generic-functions ()
2113   (let ((accessors nil))
2114     ;; Rearrange *!EARLY-GENERIC-FUNCTIONS* to speed up
2115     ;; FIX-EARLY-GENERIC-FUNCTIONS.
2116     (dolist (early-gf-spec *!early-generic-functions*)
2117       (when (every #'early-method-standard-accessor-p
2118                    (early-gf-methods (gdefinition early-gf-spec)))
2119         (push early-gf-spec accessors)))
2120     (dolist (spec (nconc accessors
2121                          '(accessor-method-slot-name
2122                            generic-function-methods
2123                            method-specializers
2124                            specializerp
2125                            specializer-type
2126                            specializer-class
2127                            slot-definition-location
2128                            slot-definition-name
2129                            class-slots
2130                            gf-arg-info
2131                            class-precedence-list
2132                            slot-boundp-using-class
2133                            (setf slot-value-using-class)
2134                            slot-value-using-class
2135                            structure-class-p
2136                            standard-class-p
2137                            funcallable-standard-class-p
2138                            specializerp)))
2139       (/show spec)
2140       (setq *!early-generic-functions*
2141             (cons spec
2142                   (delete spec *!early-generic-functions* :test #'equal))))
2143
2144     (dolist (early-gf-spec *!early-generic-functions*)
2145       (/show early-gf-spec)
2146       (let* ((gf (gdefinition early-gf-spec))
2147              (methods (mapcar (lambda (early-method)
2148                                 (let ((args (copy-list (fifth
2149                                                         early-method))))
2150                                   (setf (fourth args)
2151                                         (early-method-specializers
2152                                          early-method t))
2153                                   (apply #'real-make-a-method args)))
2154                               (early-gf-methods gf))))
2155         (setf (generic-function-method-class gf) *the-class-standard-method*)
2156         (setf (generic-function-method-combination gf)
2157               *standard-method-combination*)
2158         (set-methods gf methods)))
2159
2160     (dolist (fn *!early-functions*)
2161       (/show fn)
2162       (setf (gdefinition (car fn)) (fdefinition (caddr fn))))
2163
2164     (dolist (fixup *!generic-function-fixups*)
2165       (/show fixup)
2166       (let* ((fspec (car fixup))
2167              (gf (gdefinition fspec))
2168              (methods (mapcar (lambda (method)
2169                                 (let* ((lambda-list (first method))
2170                                        (specializers (second method))
2171                                        (method-fn-name (third method))
2172                                        (fn-name (or method-fn-name fspec))
2173                                        (fn (fdefinition fn-name))
2174                                        (initargs
2175                                         (list :function
2176                                               (set-fun-name
2177                                                (lambda (args next-methods)
2178                                                  (declare (ignore
2179                                                            next-methods))
2180                                                  (apply fn args))
2181                                                `(call ,fn-name)))))
2182                                   (declare (type function fn))
2183                                   (make-a-method 'standard-method
2184                                                  ()
2185                                                  lambda-list
2186                                                  specializers
2187                                                  initargs
2188                                                  nil)))
2189                               (cdr fixup))))
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   (/show "leaving !FIX-EARLY-GENERIC-FUNCTIONS"))
2195 \f
2196 ;;; PARSE-DEFMETHOD is used by DEFMETHOD to parse the &REST argument
2197 ;;; into the 'real' arguments. This is where the syntax of DEFMETHOD
2198 ;;; is really implemented.
2199 (defun parse-defmethod (cdr-of-form)
2200   (declare (list cdr-of-form))
2201   (let ((name (pop cdr-of-form))
2202         (qualifiers ())
2203         (spec-ll ()))
2204     (loop (if (and (car cdr-of-form) (atom (car cdr-of-form)))
2205               (push (pop cdr-of-form) qualifiers)
2206               (return (setq qualifiers (nreverse qualifiers)))))
2207     (setq spec-ll (pop cdr-of-form))
2208     (values name qualifiers spec-ll cdr-of-form)))
2209
2210 (defun parse-specializers (specializers)
2211   (declare (list specializers))
2212   (flet ((parse (spec)
2213            (let ((result (specializer-from-type spec)))
2214              (if (specializerp result)
2215                  result
2216                  (if (symbolp spec)
2217                      (error "~S was used as a specializer,~%~
2218                              but is not the name of a class."
2219                             spec)
2220                      (error "~S is not a legal specializer." spec))))))
2221     (mapcar #'parse specializers)))
2222
2223 (defun unparse-specializers (specializers-or-method)
2224   (if (listp specializers-or-method)
2225       (flet ((unparse (spec)
2226                (if (specializerp spec)
2227                    (let ((type (specializer-type spec)))
2228                      (if (and (consp type)
2229                               (eq (car type) 'class))
2230                          (let* ((class (cadr type))
2231                                 (class-name (class-name class)))
2232                            (if (eq class (find-class class-name nil))
2233                                class-name
2234                                type))
2235                          type))
2236                    (error "~S is not a legal specializer." spec))))
2237         (mapcar #'unparse specializers-or-method))
2238       (unparse-specializers (method-specializers specializers-or-method))))
2239
2240 (defun parse-method-or-spec (spec &optional (errorp t))
2241   (let (gf method name temp)
2242     (if (method-p spec)
2243         (setq method spec
2244               gf (method-generic-function method)
2245               temp (and gf (generic-function-name gf))
2246               name (if temp
2247                        (intern-fun-name
2248                          (make-method-spec temp
2249                                            (method-qualifiers method)
2250                                            (unparse-specializers
2251                                              (method-specializers method))))
2252                        (make-symbol (format nil "~S" method))))
2253         (multiple-value-bind (gf-spec quals specls)
2254             (parse-defmethod spec)
2255           (and (setq gf (and (or errorp (gboundp gf-spec))
2256                              (gdefinition gf-spec)))
2257                (let ((nreq (compute-discriminating-function-arglist-info gf)))
2258                  (setq specls (append (parse-specializers specls)
2259                                       (make-list (- nreq (length specls))
2260                                                  :initial-element
2261                                                  *the-class-t*)))
2262                  (and
2263                    (setq method (get-method gf quals specls errorp))
2264                    (setq name
2265                          (intern-fun-name (make-method-spec gf-spec
2266                                                             quals
2267                                                             specls))))))))
2268     (values gf method name)))
2269 \f
2270 (defun extract-parameters (specialized-lambda-list)
2271   (multiple-value-bind (parameters ignore1 ignore2)
2272       (parse-specialized-lambda-list specialized-lambda-list)
2273     (declare (ignore ignore1 ignore2))
2274     parameters))
2275
2276 (defun extract-lambda-list (specialized-lambda-list)
2277   (multiple-value-bind (ignore1 lambda-list ignore2)
2278       (parse-specialized-lambda-list specialized-lambda-list)
2279     (declare (ignore ignore1 ignore2))
2280     lambda-list))
2281
2282 (defun extract-specializer-names (specialized-lambda-list)
2283   (multiple-value-bind (ignore1 ignore2 specializers)
2284       (parse-specialized-lambda-list specialized-lambda-list)
2285     (declare (ignore ignore1 ignore2))
2286     specializers))
2287
2288 (defun extract-required-parameters (specialized-lambda-list)
2289   (multiple-value-bind (ignore1 ignore2 ignore3 required-parameters)
2290       (parse-specialized-lambda-list specialized-lambda-list)
2291     (declare (ignore ignore1 ignore2 ignore3))
2292     required-parameters))
2293
2294 (defun parse-specialized-lambda-list (arglist &optional post-keyword)
2295   ;;(declare (values parameters lambda-list specializers required-parameters))
2296   (let ((arg (car arglist)))
2297     (cond ((null arglist) (values nil nil nil nil))
2298           ((eq arg '&aux)
2299            (values nil arglist nil))
2300           ((memq arg lambda-list-keywords)
2301            (unless (memq arg '(&optional &rest &key &allow-other-keys &aux))
2302              ;; Now, since we try to conform to ANSI, non-standard
2303              ;; lambda-list-keywords should be treated as errors.
2304              (error 'simple-program-error
2305                     :format-control "unrecognized lambda-list keyword ~S ~
2306                      in arglist.~%"
2307                     :format-arguments (list arg)))
2308            ;; When we are at a lambda-list keyword, the parameters
2309            ;; don't include the lambda-list keyword; the lambda-list
2310            ;; does include the lambda-list keyword; and no
2311            ;; specializers are allowed to follow the lambda-list
2312            ;; keywords (at least for now).
2313            (multiple-value-bind (parameters lambda-list)
2314                (parse-specialized-lambda-list (cdr arglist) t)
2315              (when (eq arg '&rest)
2316                ;; check, if &rest is followed by a var ...
2317                (when (or (null lambda-list)
2318                          (memq (car lambda-list) lambda-list-keywords))
2319                  (error "Error in lambda-list:~%~
2320                          After &REST, a DEFMETHOD lambda-list ~
2321                          must be followed by at least one variable.")))
2322              (values parameters
2323                      (cons arg lambda-list)
2324                      ()
2325                      ())))
2326           (post-keyword
2327            ;; After a lambda-list keyword there can be no specializers.
2328            (multiple-value-bind (parameters lambda-list)
2329                (parse-specialized-lambda-list (cdr arglist) t)
2330              (values (cons (if (listp arg) (car arg) arg) parameters)
2331                      (cons arg lambda-list)
2332                      ()
2333                      ())))
2334           (t
2335            (multiple-value-bind (parameters lambda-list specializers required)
2336                (parse-specialized-lambda-list (cdr arglist))
2337              (values (cons (if (listp arg) (car arg) arg) parameters)
2338                      (cons (if (listp arg) (car arg) arg) lambda-list)
2339                      (cons (if (listp arg) (cadr arg) t) specializers)
2340                      (cons (if (listp arg) (car arg) arg) required)))))))
2341 \f
2342 (setq *boot-state* 'early)
2343 \f
2344 ;;; FIXME: In here there was a #-CMU definition of SYMBOL-MACROLET
2345 ;;; which used %WALKER stuff. That suggests to me that maybe the code
2346 ;;; walker stuff was only used for implementing stuff like that; maybe
2347 ;;; it's not needed any more? Hunt down what it was used for and see.
2348
2349 (defmacro with-slots (slots instance &body body)
2350   (let ((in (gensym)))
2351     `(let ((,in ,instance))
2352        (declare (ignorable ,in))
2353        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2354                              (third instance)
2355                              instance)))
2356            (and (symbolp instance)
2357                 `((declare (%variable-rebinding ,in ,instance)))))
2358        ,in
2359        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2360                                    (let ((var-name
2361                                           (if (symbolp slot-entry)
2362                                               slot-entry
2363                                               (car slot-entry)))
2364                                          (slot-name
2365                                           (if (symbolp slot-entry)
2366                                               slot-entry
2367                                               (cadr slot-entry))))
2368                                      `(,var-name
2369                                        (slot-value ,in ',slot-name))))
2370                                  slots)
2371                         ,@body))))
2372
2373 (defmacro with-accessors (slots instance &body body)
2374   (let ((in (gensym)))
2375     `(let ((,in ,instance))
2376        (declare (ignorable ,in))
2377        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2378                              (third instance)
2379                              instance)))
2380            (and (symbolp instance)
2381                 `((declare (%variable-rebinding ,in ,instance)))))
2382        ,in
2383        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2384                                    (let ((var-name (car slot-entry))
2385                                          (accessor-name (cadr slot-entry)))
2386                                      `(,var-name (,accessor-name ,in))))
2387                                  slots)
2388           ,@body))))