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 (declaim (notinline make-a-method
  72                     add-named-method
  73                     ensure-generic-function-using-class
  74                     add-method
  75                     remove-method))
  76
  77 (defvar *!early-functions*
  78         '((make-a-method early-make-a-method
  79                          real-make-a-method)
  80           (add-named-method early-add-named-method
  81                             real-add-named-method)
  82           ))
  83
  84 ;;; For each of the early functions, arrange to have it point to its
  85 ;;; early definition. Do this in a way that makes sure that if we
  86 ;;; redefine one of the early definitions the redefinition will take
  87 ;;; effect. This makes development easier.
  88 (dolist (fns *!early-functions*)
  89   (let ((name (car fns))
  90         (early-name (cadr fns)))
  91     (setf (gdefinition name)
  92             (set-fun-name
  93              (lambda (&rest args)
  94                (apply (fdefinition early-name) args))
  95              name))))
  96
  97 ;;; *!GENERIC-FUNCTION-FIXUPS* is used by !FIX-EARLY-GENERIC-FUNCTIONS
  98 ;;; to convert the few functions in the bootstrap which are supposed
  99 ;;; to be generic functions but can't be early on.
 100 (defvar *!generic-function-fixups*
 101   '((add-method
 102      ((generic-function method)  ;lambda-list
 103       (standard-generic-function method) ;specializers
 104       real-add-method))          ;method-function
 105     (remove-method
 106      ((generic-function method)
 107       (standard-generic-function method)
 108       real-remove-method))
 109     (get-method
 110      ((generic-function qualifiers specializers &optional (errorp t))
 111       (standard-generic-function t t)
 112       real-get-method))
 113     (ensure-generic-function-using-class
 114      ((generic-function fun-name
 115                         &key generic-function-class environment
 116                         &allow-other-keys)
 117       (generic-function t)
 118       real-ensure-gf-using-class--generic-function)
 119      ((generic-function fun-name
 120                         &key generic-function-class environment
 121                         &allow-other-keys)
 122       (null t)
 123       real-ensure-gf-using-class--null))
 124     (make-method-lambda
 125      ((proto-generic-function proto-method lambda-expression environment)
 126       (standard-generic-function standard-method t t)
 127       real-make-method-lambda))
 128     (make-method-initargs-form
 129      ((proto-generic-function proto-method
 130                               lambda-expression
 131                               lambda-list environment)
 132       (standard-generic-function standard-method t t t)
 133       real-make-method-initargs-form))
 134     (compute-effective-method
 135      ((generic-function combin applicable-methods)
 136       (generic-function standard-method-combination t)
 137       standard-compute-effective-method))))
 138 \f
 139 (defmacro defgeneric (fun-name lambda-list &body options)
 140   (declare (type list lambda-list))
 141   (unless (legal-fun-name-p fun-name)
 142     (error 'simple-program-error
 143            :format-control "illegal generic function name ~S"
 144            :format-arguments (list fun-name)))
 145   (check-gf-lambda-list lambda-list)
 146   (let ((initargs ())
 147         (methods ()))
 148     (flet ((duplicate-option (name)
 149              (error 'simple-program-error
 150                     :format-control "The option ~S appears more than once."
 151                     :format-arguments (list name)))
 152            (expand-method-definition (qab) ; QAB = qualifiers, arglist, body
 153              (let* ((arglist-pos (position-if #'listp qab))
 154                     (arglist (elt qab arglist-pos))
 155                     (qualifiers (subseq qab 0 arglist-pos))
 156                     (body (nthcdr (1+ arglist-pos) qab)))
 157                `(push (defmethod ,fun-name ,@qualifiers ,arglist ,@body)
 158                       (generic-function-initial-methods (fdefinition ',fun-name))))))
 159       (macrolet ((initarg (key) `(getf initargs ,key)))
 160         (dolist (option options)
 161           (let ((car-option (car option)))
 162             (case car-option
 163               (declare
 164                (when (and
 165                       (consp (cadr option))
 166                       (member (first (cadr option))
 167                               ;; FIXME: this list is slightly weird.
 168                               ;; ANSI (on the DEFGENERIC page) in one
 169                               ;; place allows only OPTIMIZE; in
 170                               ;; another place gives this list of
 171                               ;; disallowed declaration specifiers.
 172                               ;; This seems to be the only place where
 173                               ;; the FUNCTION declaration is
 174                               ;; mentioned; TYPE seems to be missing.
 175                               ;; Very strange.  -- CSR, 2002-10-21
 176                               '(declaration ftype function
 177                                 inline notinline special)))
 178                  (error 'simple-program-error
 179                         :format-control "The declaration specifier ~S ~
 180                                          is not allowed inside DEFGENERIC."
 181                         :format-arguments (list (cadr option))))
 182                (push (cadr option) (initarg :declarations)))
 183               (:method-combination
 184                (when (initarg car-option)
 185                  (duplicate-option car-option))
 186                (unless (symbolp (cadr option))
 187                  (error 'simple-program-error
 188                         :format-control "METHOD-COMBINATION name not a ~
 189                                          symbol: ~S"
 190                         :format-arguments (list (cadr option))))
 191                (setf (initarg car-option)
 192                      `',(cdr option)))
 193               (:argument-precedence-order
 194                (let* ((required (parse-lambda-list lambda-list))
 195                       (supplied (cdr option)))
 196                  (unless (= (length required) (length supplied))
 197                    (error 'simple-program-error
 198                           :format-control "argument count discrepancy in ~
 199                                            :ARGUMENT-PRECEDENCE-ORDER clause."
 200                           :format-arguments nil))
 201                  (when (set-difference required supplied)
 202                    (error 'simple-program-error
 203                           :format-control "unequal sets for ~
 204                                            :ARGUMENT-PRECEDENCE-ORDER clause: ~
 205                                            ~S and ~S"
 206                           :format-arguments (list required supplied)))
 207                  (setf (initarg car-option)
 208                        `',(cdr option))))
 209               ((:documentation :generic-function-class :method-class)
 210                (unless (proper-list-of-length-p option 2)
 211                  (error "bad list length for ~S" option))
 212                (if (initarg car-option)
 213                    (duplicate-option car-option)
 214                    (setf (initarg car-option) `',(cadr option))))
 215               (:method
 216                (push (cdr option) methods))
 217               (t
 218                ;; ANSI requires that unsupported things must get a
 219                ;; PROGRAM-ERROR.
 220                (error 'simple-program-error
 221                       :format-control "unsupported option ~S"
 222                       :format-arguments (list option))))))
 223
 224         (when (initarg :declarations)
 225           (setf (initarg :declarations)
 226                 `',(initarg :declarations))))
 227       `(progn
 228          (eval-when (:compile-toplevel :load-toplevel :execute)
 229            (compile-or-load-defgeneric ',fun-name))
 230          (load-defgeneric ',fun-name ',lambda-list
 231                           (sb-c:source-location) ,@initargs)
 232         ,@(mapcar #'expand-method-definition methods)
 233         (fdefinition ',fun-name)))))
 234
 235 (defun compile-or-load-defgeneric (fun-name)
 236   (proclaim-as-fun-name fun-name)
 237   (note-name-defined fun-name :function)
 238   (unless (eq (info :function :where-from fun-name) :declared)
 239     (setf (info :function :where-from fun-name) :defined)
 240     (setf (info :function :type fun-name)
 241           (specifier-type 'function))))
 242
 243 (defun load-defgeneric (fun-name lambda-list source-location &rest initargs)
 244   (when (fboundp fun-name)
 245     (style-warn "redefining ~S in DEFGENERIC" fun-name)
 246     (let ((fun (fdefinition fun-name)))
 247       (when (generic-function-p fun)
 248         (loop for method in (generic-function-initial-methods fun)
 249               do (remove-method fun method))
 250         (setf (generic-function-initial-methods fun) '()))))
 251   (apply #'ensure-generic-function
 252          fun-name
 253          :lambda-list lambda-list
 254          :definition-source source-location
 255          initargs))
 256
 257 (define-condition generic-function-lambda-list-error
 258     (reference-condition simple-program-error)
 259   ()
 260   (:default-initargs :references (list '(:ansi-cl :section (3 4 2)))))
 261
 262 (defun check-gf-lambda-list (lambda-list)
 263   (flet ((ensure (arg ok)
 264            (unless ok
 265              (error 'generic-function-lambda-list-error
 266                     :format-control
 267                     "~@<invalid ~S ~_in the generic function lambda list ~S~:>"
 268                     :format-arguments (list arg lambda-list)))))
 269     (multiple-value-bind (required optional restp rest keyp keys allowp
 270                           auxp aux morep more-context more-count)
 271         (parse-lambda-list lambda-list)
 272       (declare (ignore required)) ; since they're no different in a gf ll
 273       (declare (ignore restp rest)) ; since they're no different in a gf ll
 274       (declare (ignore allowp)) ; since &ALLOW-OTHER-KEYS is fine either way
 275       (declare (ignore aux)) ; since we require AUXP=NIL
 276       (declare (ignore more-context more-count)) ; safely ignored unless MOREP
 277       ;; no defaults allowed for &OPTIONAL arguments
 278       (dolist (i optional)
 279         (ensure i (or (symbolp i)
 280                       (and (consp i) (symbolp (car i)) (null (cdr i))))))
 281       ;; no defaults allowed for &KEY arguments
 282       (when keyp
 283         (dolist (i keys)
 284           (ensure i (or (symbolp i)
 285                         (and (consp i)
 286                              (or (symbolp (car i))
 287                                  (and (consp (car i))
 288                                       (symbolp (caar i))
 289                                       (symbolp (cadar i))
 290                                       (null (cddar i))))
 291                              (null (cdr i)))))))
 292       ;; no &AUX allowed
 293       (when auxp
 294         (error "&AUX is not allowed in a generic function lambda list: ~S"
 295                lambda-list))
 296       ;; Oh, *puhlease*... not specifically as per section 3.4.2 of
 297       ;; the ANSI spec, but the CMU CL &MORE extension does not
 298       ;; belong here!
 299       (aver (not morep)))))
 300 \f
 301 (defmacro defmethod (&rest args &environment env)
 302   (multiple-value-bind (name qualifiers lambda-list body)
 303       (parse-defmethod args)
 304     (multiple-value-bind (proto-gf proto-method)
 305         (prototypes-for-make-method-lambda name)
 306       (expand-defmethod name
 307                         proto-gf
 308                         proto-method
 309                         qualifiers
 310                         lambda-list
 311                         body
 312                         env))))
 313
 314 (defun prototypes-for-make-method-lambda (name)
 315   (if (not (eq *boot-state* 'complete))
 316       (values nil nil)
 317       (let ((gf? (and (fboundp name)
 318                       (gdefinition name))))
 319         (if (or (null gf?)
 320                 (not (generic-function-p gf?)))
 321             (values (class-prototype (find-class 'standard-generic-function))
 322                     (class-prototype (find-class 'standard-method)))
 323             (values gf?
 324                     (class-prototype (or (generic-function-method-class gf?)
 325                                          (find-class 'standard-method))))))))
 326
 327 ;;; Take a name which is either a generic function name or a list specifying
 328 ;;; a SETF generic function (like: (SETF <generic-function-name>)). Return
 329 ;;; the prototype instance of the method-class for that generic function.
 330 ;;;
 331 ;;; If there is no generic function by that name, this returns the
 332 ;;; default value, the prototype instance of the class
 333 ;;; STANDARD-METHOD. This default value is also returned if the spec
 334 ;;; names an ordinary function or even a macro. In effect, this leaves
 335 ;;; the signalling of the appropriate error until load time.
 336 ;;;
 337 ;;; Note: During bootstrapping, this function is allowed to return NIL.
 338 (defun method-prototype-for-gf (name)
 339   (let ((gf? (and (fboundp name)
 340                   (gdefinition name))))
 341     (cond ((neq *boot-state* 'complete) nil)
 342           ((or (null gf?)
 343                (not (generic-function-p gf?)))          ; Someone else MIGHT
 344                                                         ; error at load time.
 345            (class-prototype (find-class 'standard-method)))
 346           (t
 347             (class-prototype (or (generic-function-method-class gf?)
 348                                  (find-class 'standard-method)))))))
 349 \f
 350 (defun expand-defmethod (name
 351                          proto-gf
 352                          proto-method
 353                          qualifiers
 354                          lambda-list
 355                          body
 356                          env)
 357   (multiple-value-bind (method-lambda unspecialized-lambda-list specializers)
 358       (add-method-declarations name qualifiers lambda-list body env)
 359     (multiple-value-bind (method-function-lambda initargs)
 360         (make-method-lambda proto-gf proto-method method-lambda env)
 361       (let ((initargs-form (make-method-initargs-form proto-gf
 362                                                       proto-method
 363                                                       method-function-lambda
 364                                                       initargs
 365                                                       env)))
 366         `(progn
 367           ;; Note: We could DECLAIM the ftype of the generic function
 368           ;; here, since ANSI specifies that we create it if it does
 369           ;; not exist. However, I chose not to, because I think it's
 370           ;; more useful to support a style of programming where every
 371           ;; generic function has an explicit DEFGENERIC and any typos
 372           ;; in DEFMETHODs are warned about. Otherwise
 373           ;;
 374           ;;   (DEFGENERIC FOO-BAR-BLETCH ((X T)))
 375           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X HASH-TABLE)) ..)
 376           ;;   (DEFMETHOD FOO-BRA-BLETCH ((X SIMPLE-VECTOR)) ..)
 377           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X VECTOR)) ..)
 378           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X ARRAY)) ..)
 379           ;;   (DEFMETHOD FOO-BAR-BLETCH ((X LIST)) ..)
 380           ;;
 381           ;; compiles without raising an error and runs without
 382           ;; raising an error (since SIMPLE-VECTOR cases fall through
 383           ;; to VECTOR) but still doesn't do what was intended. I hate
 384           ;; that kind of bug (code which silently gives the wrong
 385           ;; answer), so we don't do a DECLAIM here. -- WHN 20000229
 386           ,(make-defmethod-form name qualifiers specializers
 387                                 unspecialized-lambda-list
 388                                 (if proto-method
 389                                     (class-name (class-of proto-method))
 390                                     'standard-method)
 391                                 initargs-form
 392                                 (getf (getf initargs :plist)
 393                                       :pv-table-symbol)))))))
 394
 395 (defun interned-symbol-p (x)
 396   (and (symbolp x) (symbol-package x)))
 397
 398 (defun make-defmethod-form (name qualifiers specializers
 399                                  unspecialized-lambda-list method-class-name
 400                                  initargs-form &optional pv-table-symbol)
 401   (let (fn
 402         fn-lambda)
 403     (if (and (interned-symbol-p (fun-name-block-name name))
 404              (every #'interned-symbol-p qualifiers)
 405              (every (lambda (s)
 406                       (if (consp s)
 407                           (and (eq (car s) 'eql)
 408                                (constantp (cadr s))
 409                                (let ((sv (constant-form-value (cadr s))))
 410                                  (or (interned-symbol-p sv)
 411                                      (integerp sv)
 412                                      (and (characterp sv)
 413                                           (standard-char-p sv)))))
 414                           (interned-symbol-p s)))
 415                     specializers)
 416              (consp initargs-form)
 417              (eq (car initargs-form) 'list*)
 418              (memq (cadr initargs-form) '(:function :fast-function))
 419              (consp (setq fn (caddr initargs-form)))
 420              (eq (car fn) 'function)
 421              (consp (setq fn-lambda (cadr fn)))
 422              (eq (car fn-lambda) 'lambda))
 423         (let* ((specls (mapcar (lambda (specl)
 424                                  (if (consp specl)
 425                                      `(,(car specl) ,(eval (cadr specl)))
 426                                    specl))
 427                                specializers))
 428                (mname `(,(if (eq (cadr initargs-form) :function)
 429                              'slow-method 'fast-method)
 430                         ,name ,@qualifiers ,specls)))
 431           `(progn
 432              (defun ,mname ,(cadr fn-lambda)
 433                ,@(cddr fn-lambda))
 434              ,(make-defmethod-form-internal
 435                name qualifiers `',specls
 436                unspecialized-lambda-list method-class-name
 437                `(list* ,(cadr initargs-form)
 438                        #',mname
 439                        ,@(cdddr initargs-form))
 440                pv-table-symbol)))
 441         (make-defmethod-form-internal
 442          name qualifiers
 443          `(list ,@(mapcar (lambda (specializer)
 444                             (if (consp specializer)
 445                                 ``(,',(car specializer)
 446                                       ,,(cadr specializer))
 447                                 `',specializer))
 448                           specializers))
 449          unspecialized-lambda-list
 450          method-class-name
 451          initargs-form
 452          pv-table-symbol))))
 453
 454 (defun make-defmethod-form-internal
 455     (name qualifiers specializers-form unspecialized-lambda-list
 456      method-class-name initargs-form &optional pv-table-symbol)
 457   `(load-defmethod
 458     ',method-class-name
 459     ',name
 460     ',qualifiers
 461     ,specializers-form
 462     ',unspecialized-lambda-list
 463     ,initargs-form
 464     ;; Paper over a bug in KCL by passing the cache-symbol here in
 465     ;; addition to in the list. FIXME: We should no longer need to do
 466     ;; this, since the CLOS code is now SBCL-specific, and doesn't
 467     ;; need to be ported to every buggy compiler in existence.
 468     ',pv-table-symbol
 469     (sb-c:source-location)))
 470
 471 (defmacro make-method-function (method-lambda &environment env)
 472   (make-method-function-internal method-lambda env))
 473
 474 (defun make-method-function-internal (method-lambda &optional env)
 475   (multiple-value-bind (proto-gf proto-method)
 476       (prototypes-for-make-method-lambda nil)
 477     (multiple-value-bind (method-function-lambda initargs)
 478         (make-method-lambda proto-gf proto-method method-lambda env)
 479       (make-method-initargs-form proto-gf
 480                                  proto-method
 481                                  method-function-lambda
 482                                  initargs
 483                                  env))))
 484
 485 (defun add-method-declarations (name qualifiers lambda-list body env)
 486   (declare (ignore env))
 487   (multiple-value-bind (parameters unspecialized-lambda-list specializers)
 488       (parse-specialized-lambda-list lambda-list)
 489     (multiple-value-bind (real-body declarations documentation)
 490         (parse-body body)
 491       (values `(lambda ,unspecialized-lambda-list
 492                  ,@(when documentation `(,documentation))
 493                  ;; (Old PCL code used a somewhat different style of
 494                  ;; list for %METHOD-NAME values. Our names use
 495                  ;; ,@QUALIFIERS instead of ,QUALIFIERS so that the
 496                  ;; method names look more like what you see in a
 497                  ;; DEFMETHOD form.)
 498                  ;;
 499                  ;; FIXME: As of sbcl-0.7.0.6, code elsewhere, at
 500                  ;; least the code to set up named BLOCKs around the
 501                  ;; bodies of methods, depends on the function's base
 502                  ;; name being the first element of the %METHOD-NAME
 503                  ;; list. It would be good to remove this dependency,
 504                  ;; perhaps by building the BLOCK here, or by using
 505                  ;; another declaration (e.g. %BLOCK-NAME), so that
 506                  ;; our method debug names are free to have any format,
 507                  ;; e.g. (:METHOD PRINT-OBJECT :AROUND (CLOWN T)).
 508                  ;;
 509                  ;; Further, as of sbcl-0.7.9.10, the code to
 510                  ;; implement NO-NEXT-METHOD is coupled to the form of
 511                  ;; this declaration; see the definition of
 512                  ;; CALL-NO-NEXT-METHOD (and the passing of
 513                  ;; METHOD-NAME-DECLARATION arguments around the
 514                  ;; various CALL-NEXT-METHOD logic).
 515                  (declare (%method-name (,name
 516                                          ,@qualifiers
 517                                          ,specializers)))
 518                  (declare (%method-lambda-list ,@lambda-list))
 519                  ,@declarations
 520                  ,@real-body)
 521               unspecialized-lambda-list specializers))))
 522
 523 (defun real-make-method-initargs-form (proto-gf proto-method
 524                                        method-lambda initargs env)
 525   (declare (ignore proto-gf proto-method))
 526   (unless (and (consp method-lambda)
 527                (eq (car method-lambda) 'lambda))
 528     (error "The METHOD-LAMBDA argument to MAKE-METHOD-FUNCTION, ~S, ~
 529             is not a lambda form."
 530            method-lambda))
 531   (make-method-initargs-form-internal method-lambda initargs env))
 532
 533 (unless (fboundp 'make-method-initargs-form)
 534   (setf (gdefinition 'make-method-initargs-form)
 535         (symbol-function 'real-make-method-initargs-form)))
 536
 537 (defun real-make-method-lambda (proto-gf proto-method method-lambda env)
 538   (declare (ignore proto-gf proto-method))
 539   (make-method-lambda-internal method-lambda env))
 540
 541 ;;; a helper function for creating Python-friendly type declarations
 542 ;;; in DEFMETHOD forms
 543 (defun parameter-specializer-declaration-in-defmethod (parameter specializer)
 544   (cond ((and (consp specializer)
 545               (eq (car specializer) 'eql))
 546          ;; KLUDGE: ANSI, in its wisdom, says that
 547          ;; EQL-SPECIALIZER-FORMs in EQL specializers are evaluated at
 548          ;; DEFMETHOD expansion time. Thus, although one might think
 549          ;; that in
 550          ;;   (DEFMETHOD FOO ((X PACKAGE)
 551          ;;                   (Y (EQL 12))
 552          ;;      ..))
 553          ;; the PACKAGE and (EQL 12) forms are both parallel type
 554          ;; names, they're not, as is made clear when you do
 555          ;;   (DEFMETHOD FOO ((X PACKAGE)
 556          ;;                   (Y (EQL 'BAR)))
 557          ;;     ..)
 558          ;; where Y needs to be a symbol named "BAR", not some cons
 559          ;; made by (CONS 'QUOTE 'BAR). I.e. when the
 560          ;; EQL-SPECIALIZER-FORM is (EQL 'X), it requires an argument
 561          ;; to be of type (EQL X). It'd be easy to transform one to
 562          ;; the other, but it'd be somewhat messier to do so while
 563          ;; ensuring that the EQL-SPECIALIZER-FORM is only EVAL'd
 564          ;; once. (The new code wouldn't be messy, but it'd require a
 565          ;; big transformation of the old code.) So instead we punt.
 566          ;; -- WHN 20000610
 567          '(ignorable))
 568         ((member specializer
 569                  ;; KLUDGE: For some low-level implementation
 570                  ;; classes, perhaps because of some problems related
 571                  ;; to the incomplete integration of PCL into SBCL's
 572                  ;; type system, some specializer classes can't be
 573                  ;; declared as argument types. E.g.
 574                  ;;   (DEFMETHOD FOO ((X SLOT-OBJECT))
 575                  ;;     (DECLARE (TYPE SLOT-OBJECT X))
 576                  ;;     ..)
 577                  ;; loses when
 578                  ;;   (DEFSTRUCT BAR A B)
 579                  ;;   (FOO (MAKE-BAR))
 580                  ;; perhaps because of the way that STRUCTURE-OBJECT
 581                  ;; inherits both from SLOT-OBJECT and from
 582                  ;; SB-KERNEL:INSTANCE. In an effort to sweep such
 583                  ;; problems under the rug, we exclude these problem
 584                  ;; cases by blacklisting them here. -- WHN 2001-01-19
 585                  '(slot-object))
 586          '(ignorable))
 587         ((not (eq *boot-state* 'complete))
 588          ;; KLUDGE: PCL, in its wisdom, sometimes calls methods with
 589          ;; types which don't match their specializers. (Specifically,
 590          ;; it calls ENSURE-CLASS-USING-CLASS (T NULL) with a non-NULL
 591          ;; second argument.) Hopefully it only does this kind of
 592          ;; weirdness when bootstrapping.. -- WHN 20000610
 593          '(ignorable))
 594         ((var-globally-special-p parameter)
 595          ;; KLUDGE: Don't declare types for global special variables
 596          ;; -- our rebinding magic for SETQ cases don't work right
 597          ;; there.
 598          ;;
 599          ;; FIXME: It would be better to detect the SETQ earlier and
 600          ;; skip declarations for specials only when needed, not
 601          ;; always.
 602          ;;
 603          ;; --NS 2004-10-14
 604          '(ignorable))
 605         (t
 606          ;; Otherwise, we can usually make Python very happy.
 607          (let ((kind (info :type :kind specializer)))
 608            (ecase kind
 609              ((:primitive) `(type ,specializer ,parameter))
 610              ((:defined)
 611               (let ((class (find-class specializer nil)))
 612                 ;; CLASS can be null here if the user has erroneously
 613                 ;; tried to use a defined type as a specializer; it
 614                 ;; can be a non-BUILT-IN-CLASS if the user defines a
 615                 ;; type and calls (SETF FIND-CLASS) in a consistent
 616                 ;; way.
 617                 (when (and class (typep class 'built-in-class))
 618                   `(type ,specializer ,parameter))))
 619              ((:instance nil)
 620               (let ((class (find-class specializer nil)))
 621                 (cond
 622                   (class
 623                    (if (typep class '(or built-in-class structure-class))
 624                        `(type ,specializer ,parameter)
 625                        ;; don't declare CLOS classes as parameters;
 626                        ;; it's too expensive.
 627                        '(ignorable)))
 628                   (t
 629                    ;; we can get here, and still not have a failure
 630                    ;; case, by doing MOP programming like (PROGN
 631                    ;; (ENSURE-CLASS 'FOO) (DEFMETHOD BAR ((X FOO))
 632                    ;; ...)).  Best to let the user know we haven't
 633                    ;; been able to extract enough information:
 634                    (style-warn
 635                     "~@<can't find type for presumed class ~S in ~S.~@:>"
 636                     specializer
 637                     'parameter-specializer-declaration-in-defmethod)
 638                    '(ignorable)))))
 639              ((:forthcoming-defclass-type) '(ignorable)))))))
 640
 641 (defun make-method-lambda-internal (method-lambda &optional env)
 642   (unless (and (consp method-lambda) (eq (car method-lambda) 'lambda))
 643     (error "The METHOD-LAMBDA argument to MAKE-METHOD-LAMBDA, ~S, ~
 644             is not a lambda form."
 645            method-lambda))
 646   (multiple-value-bind (real-body declarations documentation)
 647       (parse-body (cddr method-lambda))
 648     (let* ((name-decl (get-declaration '%method-name declarations))
 649            (sll-decl (get-declaration '%method-lambda-list declarations))
 650            (method-name (when (consp name-decl) (car name-decl)))
 651            (generic-function-name (when method-name (car method-name)))
 652            (specialized-lambda-list (or sll-decl (cadr method-lambda))))
 653       (multiple-value-bind (parameters lambda-list specializers)
 654           (parse-specialized-lambda-list specialized-lambda-list)
 655         (let* ((required-parameters
 656                 (mapcar (lambda (r s) (declare (ignore s)) r)
 657                         parameters
 658                         specializers))
 659                (slots (mapcar #'list required-parameters))
 660                (calls (list nil))
 661                (class-declarations
 662                 `(declare
 663                   ;; These declarations seem to be used by PCL to pass
 664                   ;; information to itself; when I tried to delete 'em
 665                   ;; ca. 0.6.10 it didn't work. I'm not sure how
 666                   ;; they work, but note the (VAR-DECLARATION '%CLASS ..)
 667                   ;; expression in CAN-OPTIMIZE-ACCESS1. -- WHN 2000-12-30
 668                   ,@(remove nil
 669                             (mapcar (lambda (a s) (and (symbolp s)
 670                                                        (neq s t)
 671                                                        `(%class ,a ,s)))
 672                                     parameters
 673                                     specializers))
 674                   ;; These TYPE declarations weren't in the original
 675                   ;; PCL code, but the Python compiler likes them a
 676                   ;; lot. (We're telling the compiler about our
 677                   ;; knowledge of specialized argument types so that
 678                   ;; it can avoid run-time type dispatch overhead,
 679                   ;; which can be a huge win for Python.)
 680                   ;;
 681                   ;; KLUDGE: when I tried moving these to
 682                   ;; ADD-METHOD-DECLARATIONS, things broke.  No idea
 683                   ;; why.  -- CSR, 2004-06-16
 684                   ,@(mapcar #'parameter-specializer-declaration-in-defmethod
 685                             parameters
 686                             specializers)))
 687                (method-lambda
 688                 ;; Remove the documentation string and insert the
 689                 ;; appropriate class declarations. The documentation
 690                 ;; string is removed to make it easy for us to insert
 691                 ;; new declarations later, they will just go after the
 692                 ;; CADR of the method lambda. The class declarations
 693                 ;; are inserted to communicate the class of the method's
 694                 ;; arguments to the code walk.
 695                 `(lambda ,lambda-list
 696                    ;; The default ignorability of method parameters
 697                    ;; doesn't seem to be specified by ANSI. PCL had
 698                    ;; them basically ignorable but was a little
 699                    ;; inconsistent. E.g. even though the two
 700                    ;; method definitions
 701                    ;;   (DEFMETHOD FOO ((X T) (Y T)) "Z")
 702                    ;;   (DEFMETHOD FOO ((X T) Y) "Z")
 703                    ;; are otherwise equivalent, PCL treated Y as
 704                    ;; ignorable in the first definition but not in the
 705                    ;; second definition. We make all required
 706                    ;; parameters ignorable as a way of systematizing
 707                    ;; the old PCL behavior. -- WHN 2000-11-24
 708                    (declare (ignorable ,@required-parameters))
 709                    ,class-declarations
 710                    ,@declarations
 711                    (block ,(fun-name-block-name generic-function-name)
 712                      ,@real-body)))
 713                (constant-value-p (and (null (cdr real-body))
 714                                       (constantp (car real-body))))
 715                (constant-value (and constant-value-p
 716                                     (constant-form-value (car real-body))))
 717                (plist (and constant-value-p
 718                            (or (typep constant-value
 719                                       '(or number character))
 720                                (and (symbolp constant-value)
 721                                     (symbol-package constant-value)))
 722                            (list :constant-value constant-value)))
 723                (applyp (dolist (p lambda-list nil)
 724                          (cond ((memq p '(&optional &rest &key))
 725                                 (return t))
 726                                ((eq p '&aux)
 727                                 (return nil))))))
 728           (multiple-value-bind
 729                 (walked-lambda call-next-method-p closurep
 730                                next-method-p-p setq-p)
 731               (walk-method-lambda method-lambda
 732                                   required-parameters
 733                                   env
 734                                   slots
 735                                   calls)
 736             (multiple-value-bind (walked-lambda-body
 737                                   walked-declarations
 738                                   walked-documentation)
 739                 (parse-body (cddr walked-lambda))
 740               (declare (ignore walked-documentation))
 741               (when (or next-method-p-p call-next-method-p)
 742                 (setq plist (list* :needs-next-methods-p t plist)))
 743               (when (some #'cdr slots)
 744                 (multiple-value-bind (slot-name-lists call-list)
 745                     (slot-name-lists-from-slots slots calls)
 746                   (let ((pv-table-symbol (make-symbol "pv-table")))
 747                     (setq plist
 748                           `(,@(when slot-name-lists
 749                                     `(:slot-name-lists ,slot-name-lists))
 750                               ,@(when call-list
 751                                       `(:call-list ,call-list))
 752                               :pv-table-symbol ,pv-table-symbol
 753                               ,@plist))
 754                     (setq walked-lambda-body
 755                           `((pv-binding (,required-parameters
 756                                          ,slot-name-lists
 757                                          ,pv-table-symbol)
 758                               ,@walked-lambda-body))))))
 759               (when (and (memq '&key lambda-list)
 760                          (not (memq '&allow-other-keys lambda-list)))
 761                 (let ((aux (memq '&aux lambda-list)))
 762                   (setq lambda-list (nconc (ldiff lambda-list aux)
 763                                            (list '&allow-other-keys)
 764                                            aux))))
 765               (values `(lambda (.method-args. .next-methods.)
 766                          (simple-lexical-method-functions
 767                              (,lambda-list .method-args. .next-methods.
 768                                            :call-next-method-p
 769                                            ,call-next-method-p
 770                                            :next-method-p-p ,next-method-p-p
 771                                            :setq-p ,setq-p
 772                                            ;; we need to pass this along
 773                                            ;; so that NO-NEXT-METHOD can
 774                                            ;; be given a suitable METHOD
 775                                            ;; argument; we need the
 776                                            ;; QUALIFIERS and SPECIALIZERS
 777                                            ;; inside the declaration to
 778                                            ;; give to FIND-METHOD.
 779                                            :method-name-declaration ,name-decl
 780                                            :closurep ,closurep
 781                                            :applyp ,applyp)
 782                            ,@walked-declarations
 783                            ,@walked-lambda-body))
 784                       `(,@(when plist
 785                                 `(:plist ,plist))
 786                           ,@(when documentation
 787                                   `(:documentation ,documentation)))))))))))
 788
 789 (unless (fboundp 'make-method-lambda)
 790   (setf (gdefinition 'make-method-lambda)
 791         (symbol-function 'real-make-method-lambda)))
 792
 793 (defmacro simple-lexical-method-functions ((lambda-list
 794                                             method-args
 795                                             next-methods
 796                                             &rest lmf-options)
 797                                            &body body)
 798   `(progn
 799      ,method-args ,next-methods
 800      (bind-simple-lexical-method-functions (,method-args ,next-methods
 801                                                          ,lmf-options)
 802          (bind-args (,lambda-list ,method-args)
 803            ,@body))))
 804
 805 (defmacro fast-lexical-method-functions ((lambda-list
 806                                           next-method-call
 807                                           args
 808                                           rest-arg
 809                                           &rest lmf-options)
 810                                          &body body)
 811   `(bind-fast-lexical-method-functions (,args ,rest-arg ,next-method-call ,lmf-options)
 812      (bind-args (,(nthcdr (length args) lambda-list) ,rest-arg)
 813        ,@body)))
 814
 815 (defmacro bind-simple-lexical-method-functions
 816     ((method-args next-methods (&key call-next-method-p next-method-p-p setq-p
 817                                      closurep applyp method-name-declaration))
 818      &body body
 819      &environment env)
 820   (if (not (or call-next-method-p setq-p closurep next-method-p-p applyp))
 821       `(locally
 822            ,@body)
 823       `(let ((.next-method. (car ,next-methods))
 824              (,next-methods (cdr ,next-methods)))
 825          (declare (ignorable .next-method. ,next-methods))
 826          (flet (,@(and call-next-method-p
 827                        `((call-next-method
 828                           (&rest cnm-args)
 829                           ,@(if (safe-code-p env)
 830                                 `((%check-cnm-args cnm-args
 831                                                    ,method-args
 832                                                    ',method-name-declaration))
 833                                 nil)
 834                           (if .next-method.
 835                               (funcall (if (std-instance-p .next-method.)
 836                                            (method-function .next-method.)
 837                                            .next-method.) ; for early methods
 838                                        (or cnm-args ,method-args)
 839                                        ,next-methods)
 840                               (apply #'call-no-next-method
 841                                      ',method-name-declaration
 842                                      (or cnm-args ,method-args))))))
 843                 ,@(and next-method-p-p
 844                        '((next-method-p ()
 845                           (not (null .next-method.))))))
 846            ,@body))))
 847
 848 (defun call-no-next-method (method-name-declaration &rest args)
 849   (destructuring-bind (name) method-name-declaration
 850     (destructuring-bind (name &rest qualifiers-and-specializers) name
 851       ;; KLUDGE: inefficient traversal, but hey.  This should only
 852       ;; happen on the slow error path anyway.
 853       (let* ((qualifiers (butlast qualifiers-and-specializers))
 854              (specializers (car (last qualifiers-and-specializers)))
 855              (method (find-method (gdefinition name) qualifiers specializers)))
 856         (apply #'no-next-method
 857                (method-generic-function method)
 858                method
 859                args)))))
 860
 861 (defstruct (method-call (:copier nil))
 862   (function #'identity :type function)
 863   call-method-args)
 864
 865 #-sb-fluid (declaim (sb-ext:freeze-type method-call))
 866
 867 (defmacro invoke-method-call1 (function args cm-args)
 868   `(let ((.function. ,function)
 869          (.args. ,args)
 870          (.cm-args. ,cm-args))
 871      (if (and .cm-args. (null (cdr .cm-args.)))
 872          (funcall .function. .args. (car .cm-args.))
 873          (apply .function. .args. .cm-args.))))
 874
 875 (defmacro invoke-method-call (method-call restp &rest required-args+rest-arg)
 876   `(invoke-method-call1 (method-call-function ,method-call)
 877                         ,(if restp
 878                              `(list* ,@required-args+rest-arg)
 879                              `(list ,@required-args+rest-arg))
 880                         (method-call-call-method-args ,method-call)))
 881
 882 (defstruct (fast-method-call (:copier nil))
 883   (function #'identity :type function)
 884   pv-cell
 885   next-method-call
 886   arg-info)
 887
 888 #-sb-fluid (declaim (sb-ext:freeze-type fast-method-call))
 889
 890 (defmacro fmc-funcall (fn pv-cell next-method-call &rest args)
 891   `(funcall ,fn ,pv-cell ,next-method-call ,@args))
 892
 893 (defmacro invoke-fast-method-call (method-call &rest required-args+rest-arg)
 894   `(fmc-funcall (fast-method-call-function ,method-call)
 895                 (fast-method-call-pv-cell ,method-call)
 896                 (fast-method-call-next-method-call ,method-call)
 897                 ,@required-args+rest-arg))
 898
 899 (defstruct (fast-instance-boundp (:copier nil))
 900   (index 0 :type fixnum))
 901
 902 #-sb-fluid (declaim (sb-ext:freeze-type fast-instance-boundp))
 903
 904 (eval-when (:compile-toplevel :load-toplevel :execute)
 905   (defvar *allow-emf-call-tracing-p* nil)
 906   (defvar *enable-emf-call-tracing-p* #-sb-show nil #+sb-show t))
 907 \f
 908 ;;;; effective method functions
 909
 910 (defvar *emf-call-trace-size* 200)
 911 (defvar *emf-call-trace* nil)
 912 (defvar *emf-call-trace-index* 0)
 913
 914 ;;; This function was in the CMU CL version of PCL (ca Debian 2.4.8)
 915 ;;; without explanation. It appears to be intended for debugging, so
 916 ;;; it might be useful someday, so I haven't deleted it.
 917 ;;; But it isn't documented and isn't used for anything now, so
 918 ;;; I've conditionalized it out of the base system. -- WHN 19991213
 919 #+sb-show
 920 (defun show-emf-call-trace ()
 921   (when *emf-call-trace*
 922     (let ((j *emf-call-trace-index*)
 923           (*enable-emf-call-tracing-p* nil))
 924       (format t "~&(The oldest entries are printed first)~%")
 925       (dotimes-fixnum (i *emf-call-trace-size*)
 926         (let ((ct (aref *emf-call-trace* j)))
 927           (when ct (print ct)))
 928         (incf j)
 929         (when (= j *emf-call-trace-size*)
 930           (setq j 0))))))
 931
 932 (defun trace-emf-call-internal (emf format args)
 933   (unless *emf-call-trace*
 934     (setq *emf-call-trace* (make-array *emf-call-trace-size*)))
 935   (setf (aref *emf-call-trace* *emf-call-trace-index*)
 936         (list* emf format args))
 937   (incf *emf-call-trace-index*)
 938   (when (= *emf-call-trace-index* *emf-call-trace-size*)
 939     (setq *emf-call-trace-index* 0)))
 940
 941 (defmacro trace-emf-call (emf format args)
 942   (when *allow-emf-call-tracing-p*
 943     `(when *enable-emf-call-tracing-p*
 944        (trace-emf-call-internal ,emf ,format ,args))))
 945
 946 (defmacro invoke-effective-method-function-fast
 947     (emf restp &rest required-args+rest-arg)
 948   `(progn
 949      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 950      (invoke-fast-method-call ,emf ,@required-args+rest-arg)))
 951
 952 (defmacro invoke-effective-method-function (emf restp
 953                                                 &rest required-args+rest-arg)
 954   (unless (constantp restp)
 955     (error "The RESTP argument is not constant."))
 956   ;; FIXME: The RESTP handling here is confusing and maybe slightly
 957   ;; broken if RESTP evaluates to a non-self-evaluating form. E.g. if
 958   ;;   (INVOKE-EFFECTIVE-METHOD-FUNCTION EMF '(ERROR "gotcha") ...)
 959   ;; then TRACE-EMF-CALL-CALL-INTERNAL might die on a gotcha error.
 960   (setq restp (constant-form-value restp))
 961   `(progn
 962      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 963      (cond ((typep ,emf 'fast-method-call)
 964             (invoke-fast-method-call ,emf ,@required-args+rest-arg))
 965            ;; "What," you may wonder, "do these next two clauses do?"
 966            ;; In that case, you are not a PCL implementor, for they
 967            ;; considered this to be self-documenting.:-| Or CSR, for
 968            ;; that matter, since he can also figure it out by looking
 969            ;; at it without breaking stride. For the rest of us,
 970            ;; though: From what the code is doing with .SLOTS. and
 971            ;; whatnot, evidently it's implementing SLOT-VALUEish and
 972            ;; GET-SLOT-VALUEish things. Then we can reason backwards
 973            ;; and conclude that setting EMF to a FIXNUM is an
 974            ;; optimized way to represent these slot access operations.
 975            ,@(when (and (null restp) (= 1 (length required-args+rest-arg)))
 976                `(((typep ,emf 'fixnum)
 977                   (let* ((.slots. (get-slots-or-nil
 978                                    ,(car required-args+rest-arg)))
 979                          (value (when .slots. (clos-slots-ref .slots. ,emf))))
 980                     (if (eq value +slot-unbound+)
 981                         (slot-unbound-internal ,(car required-args+rest-arg)
 982                                                ,emf)
 983                         value)))))
 984            ,@(when (and (null restp) (= 2 (length required-args+rest-arg)))
 985                `(((typep ,emf 'fixnum)
 986                   (let ((.new-value. ,(car required-args+rest-arg))
 987                         (.slots. (get-slots-or-nil
 988                                   ,(cadr required-args+rest-arg))))
 989                     (when .slots.
 990                       (setf (clos-slots-ref .slots. ,emf) .new-value.))))))
 991            ;; (In cmucl-2.4.8 there was a commented-out third ,@(WHEN
 992            ;; ...) clause here to handle SLOT-BOUNDish stuff. Since
 993            ;; there was no explanation and presumably the code is 10+
 994            ;; years stale, I simply deleted it. -- WHN)
 995            (t
 996             (etypecase ,emf
 997               (method-call
 998                (invoke-method-call ,emf ,restp ,@required-args+rest-arg))
 999               (function
1000                ,(if restp
1001                     `(apply (the function ,emf) ,@required-args+rest-arg)
1002                     `(funcall (the function ,emf)
1003                               ,@required-args+rest-arg))))))))
1004
1005 (defun invoke-emf (emf args)
1006   (trace-emf-call emf t args)
1007   (etypecase emf
1008     (fast-method-call
1009      (let* ((arg-info (fast-method-call-arg-info emf))
1010             (restp (cdr arg-info))
1011             (nreq (car arg-info)))
1012        (if restp
1013            (let* ((rest-args (nthcdr nreq args))
1014                   (req-args (ldiff args rest-args)))
1015              (apply (fast-method-call-function emf)
1016                     (fast-method-call-pv-cell emf)
1017                     (fast-method-call-next-method-call emf)
1018                     (nconc req-args (list rest-args))))
1019            (cond ((null args)
1020                   (if (eql nreq 0)
1021                       (invoke-fast-method-call emf)
1022                       (error 'simple-program-error
1023                              :format-control "invalid number of arguments: 0"
1024                              :format-arguments nil)))
1025                  ((null (cdr args))
1026                   (if (eql nreq 1)
1027                       (invoke-fast-method-call emf (car args))
1028                       (error 'simple-program-error
1029                              :format-control "invalid number of arguments: 1"
1030                              :format-arguments nil)))
1031                  ((null (cddr args))
1032                   (if (eql nreq 2)
1033                       (invoke-fast-method-call emf (car args) (cadr args))
1034                       (error 'simple-program-error
1035                              :format-control "invalid number of arguments: 2"
1036                              :format-arguments nil)))
1037                  (t
1038                   (apply (fast-method-call-function emf)
1039                          (fast-method-call-pv-cell emf)
1040                          (fast-method-call-next-method-call emf)
1041                          args))))))
1042     (method-call
1043      (apply (method-call-function emf)
1044             args
1045             (method-call-call-method-args emf)))
1046     (fixnum
1047      (cond ((null args)
1048             (error 'simple-program-error
1049                    :format-control "invalid number of arguments: 0"
1050                    :format-arguments nil))
1051            ((null (cdr args))
1052             (let* ((slots (get-slots (car args)))
1053                    (value (clos-slots-ref slots emf)))
1054               (if (eq value +slot-unbound+)
1055                   (slot-unbound-internal (car args) emf)
1056                   value)))
1057            ((null (cddr args))
1058             (setf (clos-slots-ref (get-slots (cadr args)) emf)
1059                   (car args)))
1060            (t (error 'simple-program-error
1061                      :format-control "invalid number of arguments"
1062                      :format-arguments nil))))
1063     (fast-instance-boundp
1064      (if (or (null args) (cdr args))
1065          (error 'simple-program-error
1066                 :format-control "invalid number of arguments"
1067                 :format-arguments nil)
1068          (let ((slots (get-slots (car args))))
1069            (not (eq (clos-slots-ref slots (fast-instance-boundp-index emf))
1070                     +slot-unbound+)))))
1071     (function
1072      (apply emf args))))
1073 \f
1074
1075 (defmacro fast-narrowed-emf (emf)
1076   ;; INVOKE-EFFECTIVE-METHOD-FUNCTION has code in it to dispatch on
1077   ;; the possibility that EMF might be of type FIXNUM (as an optimized
1078   ;; representation of a slot accessor). But as far as I (WHN
1079   ;; 2002-06-11) can tell, it's impossible for such a representation
1080   ;; to end up as .NEXT-METHOD-CALL. By reassuring INVOKE-E-M-F that
1081   ;; when called from this context it needn't worry about the FIXNUM
1082   ;; case, we can keep those cases from being compiled, which is good
1083   ;; both because it saves bytes and because it avoids annoying type
1084   ;; mismatch compiler warnings.
1085   ;;
1086   ;; KLUDGE: In sbcl-0.7.4.29, the compiler's type system isn't smart
1087   ;; enough about NOT and intersection types to benefit from a (NOT
1088   ;; FIXNUM) declaration here. -- WHN 2002-06-12 (FIXME: maybe it is
1089   ;; now... -- CSR, 2003-06-07)
1090   ;;
1091   ;; FIXME: Might the FUNCTION type be omittable here, leaving only
1092   ;; METHOD-CALLs? Failing that, could this be documented somehow?
1093   ;; (It'd be nice if the types involved could be understood without
1094   ;; solving the halting problem.)
1095   `(the (or function method-call fast-method-call)
1096      ,emf))
1097
1098 (defmacro fast-call-next-method-body ((args next-method-call rest-arg)
1099                                       method-name-declaration
1100                                       cnm-args)
1101   `(if ,next-method-call
1102        ,(let ((call `(invoke-effective-method-function
1103                       (fast-narrowed-emf ,next-method-call)
1104                       ,(not (null rest-arg))
1105                       ,@args
1106                       ,@(when rest-arg `(,rest-arg)))))
1107              `(if ,cnm-args
1108                   (bind-args ((,@args
1109                                ,@(when rest-arg
1110                                        `(&rest ,rest-arg)))
1111                               ,cnm-args)
1112                     ,call)
1113                   ,call))
1114        (call-no-next-method ',method-name-declaration
1115                             ,@args
1116                             ,@(when rest-arg
1117                                     `(,rest-arg)))))
1118
1119 (defmacro bind-fast-lexical-method-functions
1120     ((args rest-arg next-method-call (&key
1121                                       call-next-method-p
1122                                       setq-p
1123                                       method-name-declaration
1124                                       next-method-p-p
1125                                       closurep
1126                                       applyp))
1127      &body body
1128      &environment env)
1129   (let* ((all-params (append args (when rest-arg (list rest-arg))))
1130          (rebindings (when (or setq-p call-next-method-p)
1131                        (mapcar (lambda (x) (list x x)) all-params))))
1132     (if (not (or call-next-method-p setq-p closurep next-method-p-p applyp))
1133         `(locally
1134              ,@body)
1135         `(flet (,@(when call-next-method-p
1136                         `((call-next-method (&rest cnm-args)
1137                            (declare (muffle-conditions code-deletion-note))
1138                            ,@(if (safe-code-p env)
1139                                  `((%check-cnm-args cnm-args (list ,@args)
1140                                                     ',method-name-declaration))
1141                                  nil)
1142                            (fast-call-next-method-body (,args
1143                                                         ,next-method-call
1144                                                         ,rest-arg)
1145                                                         ,method-name-declaration
1146                                                        cnm-args))))
1147                 ,@(when next-method-p-p
1148                         `((next-method-p
1149                            ()
1150                            (not (null ,next-method-call))))))
1151            (let ,rebindings
1152              ,@(when rebindings `((declare (ignorable ,@all-params))))
1153              ,@body)))))
1154
1155 ;;; CMUCL comment (Gerd Moellmann):
1156 ;;;
1157 ;;; The standard says it's an error if CALL-NEXT-METHOD is called with
1158 ;;; arguments, and the set of methods applicable to those arguments is
1159 ;;; different from the set of methods applicable to the original
1160 ;;; method arguments.  (According to Barry Margolin, this rule was
1161 ;;; probably added to ensure that before and around methods are always
1162 ;;; run before primary methods.)
1163 ;;;
1164 ;;; This could be optimized for the case that the generic function
1165 ;;; doesn't have hairy methods, does have standard method combination,
1166 ;;; is a standard generic function, there are no methods defined on it
1167 ;;; for COMPUTE-APPLICABLE-METHODS and probably a lot more of such
1168 ;;; preconditions.  That looks hairy and is probably not worth it,
1169 ;;; because this check will never be fast.
1170 (defun %check-cnm-args (cnm-args orig-args method-name-declaration)
1171   (when cnm-args
1172     (let* ((gf (fdefinition (caar method-name-declaration)))
1173            (omethods (compute-applicable-methods gf orig-args))
1174            (nmethods (compute-applicable-methods gf cnm-args)))
1175       (unless (equal omethods nmethods)
1176         (error "~@<The set of methods ~S applicable to argument~P ~
1177                 ~{~S~^, ~} to call-next-method is different from ~
1178                 the set of methods ~S applicable to the original ~
1179                 method argument~P ~{~S~^, ~}.~@:>"
1180                nmethods (length cnm-args) cnm-args omethods
1181                (length orig-args) orig-args)))))
1182
1183 (defmacro bind-args ((lambda-list args) &body body)
1184   (let ((args-tail '.args-tail.)
1185         (key '.key.)
1186         (state 'required))
1187     (flet ((process-var (var)
1188              (if (memq var lambda-list-keywords)
1189                  (progn
1190                    (case var
1191                      (&optional       (setq state 'optional))
1192                      (&key            (setq state 'key))
1193                      (&allow-other-keys)
1194                      (&rest           (setq state 'rest))
1195                      (&aux            (setq state 'aux))
1196                      (otherwise
1197                       (error
1198                        "encountered the non-standard lambda list keyword ~S"
1199                        var)))
1200                    nil)
1201                  (case state
1202                    (required `((,var (pop ,args-tail))))
1203                    (optional (cond ((not (consp var))
1204                                     `((,var (when ,args-tail
1205                                               (pop ,args-tail)))))
1206                                    ((null (cddr var))
1207                                     `((,(car var) (if ,args-tail
1208                                                       (pop ,args-tail)
1209                                                       ,(cadr var)))))
1210                                    (t
1211                                     `((,(caddr var) ,args-tail)
1212                                       (,(car var) (if ,args-tail
1213                                                       (pop ,args-tail)
1214                                                       ,(cadr var)))))))
1215                    (rest `((,var ,args-tail)))
1216                    (key (cond ((not (consp var))
1217                                `((,var (car
1218                                         (get-key-arg-tail ,(keywordicate var)
1219                                                           ,args-tail)))))
1220                               ((null (cddr var))
1221                                (multiple-value-bind (keyword variable)
1222                                    (if (consp (car var))
1223                                        (values (caar var)
1224                                                (cadar var))
1225                                        (values (keywordicate (car var))
1226                                                (car var)))
1227                                  `((,key (get-key-arg-tail ',keyword
1228                                                            ,args-tail))
1229                                    (,variable (if ,key
1230                                                   (car ,key)
1231                                                   ,(cadr var))))))
1232                               (t
1233                                (multiple-value-bind (keyword variable)
1234                                    (if (consp (car var))
1235                                        (values (caar var)
1236                                                (cadar var))
1237                                        (values (keywordicate (car var))
1238                                                (car var)))
1239                                  `((,key (get-key-arg-tail ',keyword
1240                                                            ,args-tail))
1241                                    (,(caddr var) ,key)
1242                                    (,variable (if ,key
1243                                                   (car ,key)
1244                                                   ,(cadr var))))))))
1245                    (aux `(,var))))))
1246       (let ((bindings (mapcan #'process-var lambda-list)))
1247         `(let* ((,args-tail ,args)
1248                 ,@bindings
1249                 (.dummy0.
1250                  ,@(when (eq state 'optional)
1251                      `((unless (null ,args-tail)
1252                          (error 'simple-program-error
1253                                 :format-control "surplus arguments: ~S"
1254                                 :format-arguments (list ,args-tail)))))))
1255            (declare (ignorable ,args-tail .dummy0.))
1256            ,@body)))))
1257
1258 (defun get-key-arg-tail (keyword list)
1259   (loop for (key . tail) on list by #'cddr
1260         when (null tail) do
1261           ;; FIXME: Do we want to export this symbol? Or maybe use an
1262           ;; (ERROR 'SIMPLE-PROGRAM-ERROR) form?
1263           (sb-c::%odd-key-args-error)
1264         when (eq key keyword)
1265           return tail))
1266
1267 (defun walk-method-lambda (method-lambda required-parameters env slots calls)
1268   (let ((call-next-method-p nil)   ; flag indicating that CALL-NEXT-METHOD
1269                                    ; should be in the method definition
1270         (closurep nil)             ; flag indicating that #'CALL-NEXT-METHOD
1271                                    ; was seen in the body of a method
1272         (next-method-p-p nil)      ; flag indicating that NEXT-METHOD-P
1273                                    ; should be in the method definition
1274         (setq-p nil))
1275     (flet ((walk-function (form context env)
1276              (cond ((not (eq context :eval)) form)
1277                    ;; FIXME: Jumping to a conclusion from the way it's used
1278                    ;; above, perhaps CONTEXT should be called SITUATION
1279                    ;; (after the term used in the ANSI specification of
1280                    ;; EVAL-WHEN) and given modern ANSI keyword values
1281                    ;; like :LOAD-TOPLEVEL.
1282                    ((not (listp form)) form)
1283                    ((eq (car form) 'call-next-method)
1284                     (setq call-next-method-p t)
1285                     form)
1286                    ((eq (car form) 'next-method-p)
1287                     (setq next-method-p-p t)
1288                     form)
1289                    ((memq (car form) '(setq multiple-value-setq))
1290                     ;; FIXME: this is possibly a little strong as
1291                     ;; conditions go.  Ideally we would want to detect
1292                     ;; which, if any, of the method parameters are
1293                     ;; being set, and communicate that information to
1294                     ;; e.g. SPLIT-DECLARATIONS.  However, the brute
1295                     ;; force method doesn't really cost much; a little
1296                     ;; loss of discrimination over IGNORED variables
1297                     ;; should be all.  -- CSR, 2004-07-01
1298                     (setq setq-p t)
1299                     form)
1300                    ((and (eq (car form) 'function)
1301                          (cond ((eq (cadr form) 'call-next-method)
1302                                 (setq call-next-method-p t)
1303                                 (setq closurep t)
1304                                 form)
1305                                ((eq (cadr form) 'next-method-p)
1306                                 (setq next-method-p-p t)
1307                                 (setq closurep t)
1308                                 form)
1309                                (t nil))))
1310                    ((and (memq (car form)
1311                                '(slot-value set-slot-value slot-boundp))
1312                          (constantp (caddr form)))
1313                      (let ((parameter (can-optimize-access form
1314                                                            required-parameters
1315                                                            env)))
1316                       (let ((fun (ecase (car form)
1317                                    (slot-value #'optimize-slot-value)
1318                                    (set-slot-value #'optimize-set-slot-value)
1319                                    (slot-boundp #'optimize-slot-boundp))))
1320                         (funcall fun slots parameter form))))
1321                    ((and (eq (car form) 'apply)
1322                          (consp (cadr form))
1323                          (eq (car (cadr form)) 'function)
1324                          (generic-function-name-p (cadr (cadr form))))
1325                     (optimize-generic-function-call
1326                      form required-parameters env slots calls))
1327                    ((generic-function-name-p (car form))
1328                     (optimize-generic-function-call
1329                      form required-parameters env slots calls))
1330                    (t form))))
1331
1332       (let ((walked-lambda (walk-form method-lambda env #'walk-function)))
1333         (values walked-lambda
1334                 call-next-method-p
1335                 closurep
1336                 next-method-p-p
1337                 setq-p)))))
1338
1339 (defun generic-function-name-p (name)
1340   (and (legal-fun-name-p name)
1341        (fboundp name)
1342        (if (eq *boot-state* 'complete)
1343            (standard-generic-function-p (gdefinition name))
1344            (funcallable-instance-p (gdefinition name)))))
1345 \f
1346 (defvar *method-function-plist* (make-hash-table :test 'eq))
1347 (defvar *mf1* nil)
1348 (defvar *mf1p* nil)
1349 (defvar *mf1cp* nil)
1350 (defvar *mf2* nil)
1351 (defvar *mf2p* nil)
1352 (defvar *mf2cp* nil)
1353
1354 (defun method-function-plist (method-function)
1355   (unless (eq method-function *mf1*)
1356     (rotatef *mf1* *mf2*)
1357     (rotatef *mf1p* *mf2p*)
1358     (rotatef *mf1cp* *mf2cp*))
1359   (unless (or (eq method-function *mf1*) (null *mf1cp*))
1360     (setf (gethash *mf1* *method-function-plist*) *mf1p*))
1361   (unless (eq method-function *mf1*)
1362     (setf *mf1* method-function
1363           *mf1cp* nil
1364           *mf1p* (gethash method-function *method-function-plist*)))
1365   *mf1p*)
1366
1367 (defun (setf method-function-plist)
1368     (val method-function)
1369   (unless (eq method-function *mf1*)
1370     (rotatef *mf1* *mf2*)
1371     (rotatef *mf1cp* *mf2cp*)
1372     (rotatef *mf1p* *mf2p*))
1373   (unless (or (eq method-function *mf1*) (null *mf1cp*))
1374     (setf (gethash *mf1* *method-function-plist*) *mf1p*))
1375   (setf *mf1* method-function
1376         *mf1cp* t
1377         *mf1p* val))
1378
1379 (defun method-function-get (method-function key &optional default)
1380   (getf (method-function-plist method-function) key default))
1381
1382 (defun (setf method-function-get)
1383     (val method-function key)
1384   (setf (getf (method-function-plist method-function) key) val))
1385
1386 (defun method-function-pv-table (method-function)
1387   (method-function-get method-function :pv-table))
1388
1389 (defun method-function-method (method-function)
1390   (method-function-get method-function :method))
1391
1392 (defun method-function-needs-next-methods-p (method-function)
1393   (method-function-get method-function :needs-next-methods-p t))
1394 \f
1395 (defmacro method-function-closure-generator (method-function)
1396   `(method-function-get ,method-function 'closure-generator))
1397
1398 (defun load-defmethod
1399     (class name quals specls ll initargs pv-table-symbol source-location)
1400   (setq initargs (copy-tree initargs))
1401   (let ((method-spec (or (getf initargs :method-spec)
1402                          (make-method-spec name quals specls))))
1403     (setf (getf initargs :method-spec) method-spec)
1404     (load-defmethod-internal class name quals specls
1405                              ll initargs pv-table-symbol
1406                              source-location)))
1407
1408 (defun load-defmethod-internal
1409     (method-class gf-spec qualifiers specializers lambda-list
1410                   initargs pv-table-symbol source-location)
1411   (when pv-table-symbol
1412     (setf (getf (getf initargs :plist) :pv-table-symbol)
1413           pv-table-symbol))
1414   (when (and (eq *boot-state* 'complete)
1415              (fboundp gf-spec))
1416     (let* ((gf (fdefinition gf-spec))
1417            (method (and (generic-function-p gf)
1418                         (generic-function-methods gf)
1419                         (find-method gf
1420                                      qualifiers
1421                                      (parse-specializers specializers)
1422                                      nil))))
1423       (when method
1424         (style-warn "redefining ~S~{ ~S~} ~S in DEFMETHOD"
1425                     gf-spec qualifiers specializers))))
1426   (let ((method (apply #'add-named-method
1427                        gf-spec qualifiers specializers lambda-list
1428                        :definition-source source-location
1429                        initargs)))
1430     (unless (or (eq method-class 'standard-method)
1431                 (eq (find-class method-class nil) (class-of method)))
1432       ;; FIXME: should be STYLE-WARNING?
1433       (format *error-output*
1434               "~&At the time the method with qualifiers ~:S and~%~
1435                specializers ~:S on the generic function ~S~%~
1436                was compiled, the method-class for that generic function was~%~
1437                ~S. But, the method class is now ~S, this~%~
1438                may mean that this method was compiled improperly.~%"
1439               qualifiers specializers gf-spec
1440               method-class (class-name (class-of method))))
1441     method))
1442
1443 (defun make-method-spec (gf-spec qualifiers unparsed-specializers)
1444   `(slow-method ,gf-spec ,@qualifiers ,unparsed-specializers))
1445
1446 (defun initialize-method-function (initargs &optional return-function-p method)
1447   (let* ((mf (getf initargs :function))
1448          (method-spec (getf initargs :method-spec))
1449          (plist (getf initargs :plist))
1450          (pv-table-symbol (getf plist :pv-table-symbol))
1451          (pv-table nil)
1452          (mff (getf initargs :fast-function)))
1453     (flet ((set-mf-property (p v)
1454              (when mf
1455                (setf (method-function-get mf p) v))
1456              (when mff
1457                (setf (method-function-get mff p) v))))
1458       (when method-spec
1459         (when mf
1460           (setq mf (set-fun-name mf method-spec)))
1461         (when mff
1462           (let ((name `(fast-method ,@(cdr method-spec))))
1463             (set-fun-name mff name)
1464             (unless mf
1465               (set-mf-property :name name)))))
1466       (when plist
1467         (let ((snl (getf plist :slot-name-lists))
1468               (cl (getf plist :call-list)))
1469           (when (or snl cl)
1470             (setq pv-table (intern-pv-table :slot-name-lists snl
1471                                             :call-list cl))
1472             (when pv-table (set pv-table-symbol pv-table))
1473             (set-mf-property :pv-table pv-table)))
1474         (loop (when (null plist) (return nil))
1475               (set-mf-property (pop plist) (pop plist)))
1476         (when method
1477           (set-mf-property :method method))
1478         (when return-function-p
1479           (or mf (method-function-from-fast-function mff)))))))
1480 \f
1481 (defun analyze-lambda-list (lambda-list)
1482   (flet (;; FIXME: Is this redundant with SB-C::MAKE-KEYWORD-FOR-ARG?
1483          (parse-key-arg (arg)
1484            (if (listp arg)
1485                (if (listp (car arg))
1486                    (caar arg)
1487                    (keywordicate (car arg)))
1488                (keywordicate arg))))
1489     (let ((nrequired 0)
1490           (noptional 0)
1491           (keysp nil)
1492           (restp nil)
1493           (nrest 0)
1494           (allow-other-keys-p nil)
1495           (keywords ())
1496           (keyword-parameters ())
1497           (state 'required))
1498       (dolist (x lambda-list)
1499         (if (memq x lambda-list-keywords)
1500             (case x
1501               (&optional         (setq state 'optional))
1502               (&key              (setq keysp t
1503                                        state 'key))
1504               (&allow-other-keys (setq allow-other-keys-p t))
1505               (&rest             (setq restp t
1506                                        state 'rest))
1507               (&aux           (return t))
1508               (otherwise
1509                 (error "encountered the non-standard lambda list keyword ~S"
1510                        x)))
1511             (ecase state
1512               (required  (incf nrequired))
1513               (optional  (incf noptional))
1514               (key       (push (parse-key-arg x) keywords)
1515                          (push x keyword-parameters))
1516               (rest      (incf nrest)))))
1517       (when (and restp (zerop nrest))
1518         (error "Error in lambda-list:~%~
1519                 After &REST, a DEFGENERIC lambda-list ~
1520                 must be followed by at least one variable."))
1521       (values nrequired noptional keysp restp allow-other-keys-p
1522               (reverse keywords)
1523               (reverse keyword-parameters)))))
1524
1525 (defun keyword-spec-name (x)
1526   (let ((key (if (atom x) x (car x))))
1527     (if (atom key)
1528         (keywordicate key)
1529         (car key))))
1530
1531 (defun ftype-declaration-from-lambda-list (lambda-list name)
1532   (multiple-value-bind (nrequired noptional keysp restp allow-other-keys-p
1533                                   keywords keyword-parameters)
1534       (analyze-lambda-list lambda-list)
1535     (declare (ignore keyword-parameters))
1536     (let* ((old (info :function :type name)) ;FIXME:FDOCUMENTATION instead?
1537            (old-ftype (if (fun-type-p old) old nil))
1538            (old-restp (and old-ftype (fun-type-rest old-ftype)))
1539            (old-keys (and old-ftype
1540                           (mapcar #'key-info-name
1541                                   (fun-type-keywords
1542                                    old-ftype))))
1543            (old-keysp (and old-ftype (fun-type-keyp old-ftype)))
1544            (old-allowp (and old-ftype
1545                             (fun-type-allowp old-ftype)))
1546            (keywords (union old-keys (mapcar #'keyword-spec-name keywords))))
1547       `(function ,(append (make-list nrequired :initial-element t)
1548                           (when (plusp noptional)
1549                             (append '(&optional)
1550                                     (make-list noptional :initial-element t)))
1551                           (when (or restp old-restp)
1552                             '(&rest t))
1553                           (when (or keysp old-keysp)
1554                             (append '(&key)
1555                                     (mapcar (lambda (key)
1556                                               `(,key t))
1557                                             keywords)
1558                                     (when (or allow-other-keys-p old-allowp)
1559                                       '(&allow-other-keys)))))
1560                  *))))
1561
1562 (defun defgeneric-declaration (spec lambda-list)
1563   `(ftype ,(ftype-declaration-from-lambda-list lambda-list spec) ,spec))
1564 \f
1565 ;;;; early generic function support
1566
1567 (defvar *!early-generic-functions* ())
1568
1569 (defun ensure-generic-function (fun-name
1570                                 &rest all-keys
1571                                 &key environment source-location
1572                                 &allow-other-keys)
1573   (declare (ignore environment))
1574   (let ((existing (and (fboundp fun-name)
1575                        (gdefinition fun-name))))
1576     (if (and existing
1577              (eq *boot-state* 'complete)
1578              (null (generic-function-p existing)))
1579         (generic-clobbers-function fun-name)
1580         (apply #'ensure-generic-function-using-class
1581                existing fun-name all-keys))))
1582
1583 (defun generic-clobbers-function (fun-name)
1584   (error 'simple-program-error
1585          :format-control "~S already names an ordinary function or a macro."
1586          :format-arguments (list fun-name)))
1587
1588 (defvar *sgf-wrapper*
1589   (boot-make-wrapper (early-class-size 'standard-generic-function)
1590                      'standard-generic-function))
1591
1592 (defvar *sgf-slots-init*
1593   (mapcar (lambda (canonical-slot)
1594             (if (memq (getf canonical-slot :name) '(arg-info source))
1595                 +slot-unbound+
1596                 (let ((initfunction (getf canonical-slot :initfunction)))
1597                   (if initfunction
1598                       (funcall initfunction)
1599                       +slot-unbound+))))
1600           (early-collect-inheritance 'standard-generic-function)))
1601
1602 (defvar *sgf-method-class-index*
1603   (!bootstrap-slot-index 'standard-generic-function 'method-class))
1604
1605 (defun early-gf-p (x)
1606   (and (fsc-instance-p x)
1607        (eq (clos-slots-ref (get-slots x) *sgf-method-class-index*)
1608            +slot-unbound+)))
1609
1610 (defvar *sgf-methods-index*
1611   (!bootstrap-slot-index 'standard-generic-function 'methods))
1612
1613 (defmacro early-gf-methods (gf)
1614   `(clos-slots-ref (get-slots ,gf) *sgf-methods-index*))
1615
1616 (defun safe-generic-function-methods (generic-function)
1617   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1618       (clos-slots-ref (get-slots generic-function) *sgf-methods-index*)
1619       (generic-function-methods generic-function)))
1620
1621 (defvar *sgf-arg-info-index*
1622   (!bootstrap-slot-index 'standard-generic-function 'arg-info))
1623
1624 (defmacro early-gf-arg-info (gf)
1625   `(clos-slots-ref (get-slots ,gf) *sgf-arg-info-index*))
1626
1627 (defvar *sgf-dfun-state-index*
1628   (!bootstrap-slot-index 'standard-generic-function 'dfun-state))
1629
1630 (defstruct (arg-info
1631             (:conc-name nil)
1632             (:constructor make-arg-info ())
1633             (:copier nil))
1634   (arg-info-lambda-list :no-lambda-list)
1635   arg-info-precedence
1636   arg-info-metatypes
1637   arg-info-number-optional
1638   arg-info-key/rest-p
1639   arg-info-keys   ;nil        no &KEY or &REST allowed
1640                   ;(k1 k2 ..) Each method must accept these &KEY arguments.
1641                   ;T          must have &KEY or &REST
1642
1643   gf-info-simple-accessor-type ; nil, reader, writer, boundp
1644   (gf-precompute-dfun-and-emf-p nil) ; set by set-arg-info
1645
1646   gf-info-static-c-a-m-emf
1647   (gf-info-c-a-m-emf-std-p t)
1648   gf-info-fast-mf-p)
1649
1650 #-sb-fluid (declaim (sb-ext:freeze-type arg-info))
1651
1652 (defun arg-info-valid-p (arg-info)
1653   (not (null (arg-info-number-optional arg-info))))
1654
1655 (defun arg-info-applyp (arg-info)
1656   (or (plusp (arg-info-number-optional arg-info))
1657       (arg-info-key/rest-p arg-info)))
1658
1659 (defun arg-info-number-required (arg-info)
1660   (length (arg-info-metatypes arg-info)))
1661
1662 (defun arg-info-nkeys (arg-info)
1663   (count-if (lambda (x) (neq x t)) (arg-info-metatypes arg-info)))
1664
1665 (defun create-gf-lambda-list (lambda-list)
1666   ;;; Create a gf lambda list from a method lambda list
1667   (loop for x in lambda-list
1668         collect (if (consp x) (list (car x)) x)
1669         if (eq x '&key) do (loop-finish)))
1670
1671 (defun set-arg-info (gf &key new-method (lambda-list nil lambda-list-p)
1672                         argument-precedence-order)
1673   (let* ((arg-info (if (eq *boot-state* 'complete)
1674                        (gf-arg-info gf)
1675                        (early-gf-arg-info gf)))
1676          (methods (if (eq *boot-state* 'complete)
1677                       (generic-function-methods gf)
1678                       (early-gf-methods gf)))
1679          (was-valid-p (integerp (arg-info-number-optional arg-info)))
1680          (first-p (and new-method (null (cdr methods)))))
1681     (when (and (not lambda-list-p) methods)
1682       (setq lambda-list (gf-lambda-list gf)))
1683     (when (or lambda-list-p
1684               (and first-p
1685                    (eq (arg-info-lambda-list arg-info) :no-lambda-list)))
1686       (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1687           (analyze-lambda-list lambda-list)
1688         (when (and methods (not first-p))
1689           (let ((gf-nreq (arg-info-number-required arg-info))
1690                 (gf-nopt (arg-info-number-optional arg-info))
1691                 (gf-key/rest-p (arg-info-key/rest-p arg-info)))
1692             (unless (and (= nreq gf-nreq)
1693                          (= nopt gf-nopt)
1694                          (eq (or keysp restp) gf-key/rest-p))
1695               (error "The lambda-list ~S is incompatible with ~
1696                      existing methods of ~S."
1697                      lambda-list gf))))
1698         (setf (arg-info-lambda-list arg-info)
1699               (if lambda-list-p
1700                   lambda-list
1701                    (create-gf-lambda-list lambda-list)))
1702         (when (or lambda-list-p argument-precedence-order
1703                   (null (arg-info-precedence arg-info)))
1704           (setf (arg-info-precedence arg-info)
1705                 (compute-precedence lambda-list nreq argument-precedence-order)))
1706         (setf (arg-info-metatypes arg-info) (make-list nreq))
1707         (setf (arg-info-number-optional arg-info) nopt)
1708         (setf (arg-info-key/rest-p arg-info) (not (null (or keysp restp))))
1709         (setf (arg-info-keys arg-info)
1710               (if lambda-list-p
1711                   (if allow-other-keys-p t keywords)
1712                   (arg-info-key/rest-p arg-info)))))
1713     (when new-method
1714       (check-method-arg-info gf arg-info new-method))
1715     (set-arg-info1 gf arg-info new-method methods was-valid-p first-p)
1716     arg-info))
1717
1718 (defun check-method-arg-info (gf arg-info method)
1719   (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1720       (analyze-lambda-list (if (consp method)
1721                                (early-method-lambda-list method)
1722                                (method-lambda-list method)))
1723     (flet ((lose (string &rest args)
1724              (error 'simple-program-error
1725                     :format-control "~@<attempt to add the method~2I~_~S~I~_~
1726                                      to the generic function~2I~_~S;~I~_~
1727                                      but ~?~:>"
1728                     :format-arguments (list method gf string args)))
1729            (comparison-description (x y)
1730              (if (> x y) "more" "fewer")))
1731       (let ((gf-nreq (arg-info-number-required arg-info))
1732             (gf-nopt (arg-info-number-optional arg-info))
1733             (gf-key/rest-p (arg-info-key/rest-p arg-info))
1734             (gf-keywords (arg-info-keys arg-info)))
1735         (unless (= nreq gf-nreq)
1736           (lose
1737            "the method has ~A required arguments than the generic function."
1738            (comparison-description nreq gf-nreq)))
1739         (unless (= nopt gf-nopt)
1740           (lose
1741            "the method has ~A optional arguments than the generic function."
1742            (comparison-description nopt gf-nopt)))
1743         (unless (eq (or keysp restp) gf-key/rest-p)
1744           (lose
1745            "the method and generic function differ in whether they accept~_~
1746             &REST or &KEY arguments."))
1747         (when (consp gf-keywords)
1748           (unless (or (and restp (not keysp))
1749                       allow-other-keys-p
1750                       (every (lambda (k) (memq k keywords)) gf-keywords))
1751             (lose "the method does not accept each of the &KEY arguments~2I~_~
1752                    ~S."
1753                   gf-keywords)))))))
1754
1755 (defvar *sm-specializers-index*
1756   (!bootstrap-slot-index 'standard-method 'specializers))
1757 (defvar *sm-fast-function-index*
1758   (!bootstrap-slot-index 'standard-method 'fast-function))
1759 (defvar *sm-%function-index*
1760   (!bootstrap-slot-index 'standard-method '%function))
1761 (defvar *sm-plist-index*
1762   (!bootstrap-slot-index 'standard-method 'plist))
1763
1764 ;;; FIXME: we don't actually need this; we could test for the exact
1765 ;;; class and deal with it as appropriate.  In fact we probably don't
1766 ;;; need it anyway because we only use this for METHOD-SPECIALIZERS on
1767 ;;; the standard reader method for METHOD-SPECIALIZERS.  Probably.
1768 (dolist (s '(specializers fast-function %function plist))
1769   (aver (= (symbol-value (intern (format nil "*SM-~A-INDEX*" s)))
1770            (!bootstrap-slot-index 'standard-reader-method s)
1771            (!bootstrap-slot-index 'standard-writer-method s)
1772            (!bootstrap-slot-index 'standard-boundp-method s))))
1773
1774 (defun safe-method-specializers (method)
1775   (let ((standard-method-classes
1776          (list *the-class-standard-method*
1777                *the-class-standard-reader-method*
1778                *the-class-standard-writer-method*
1779                *the-class-standard-boundp-method*))
1780         (class (class-of method)))
1781     (if (member class standard-method-classes)
1782         (clos-slots-ref (get-slots method) *sm-specializers-index*)
1783         (method-specializers method))))
1784 (defun safe-method-fast-function (method)
1785   (let ((standard-method-classes
1786          (list *the-class-standard-method*
1787                *the-class-standard-reader-method*
1788                *the-class-standard-writer-method*
1789                *the-class-standard-boundp-method*))
1790         (class (class-of method)))
1791     (if (member class standard-method-classes)
1792         (clos-slots-ref (get-slots method) *sm-fast-function-index*)
1793         (method-fast-function method))))
1794 (defun safe-method-function (method)
1795   (let ((standard-method-classes
1796          (list *the-class-standard-method*
1797                *the-class-standard-reader-method*
1798                *the-class-standard-writer-method*
1799                *the-class-standard-boundp-method*))
1800         (class (class-of method)))
1801     (if (member class standard-method-classes)
1802         (clos-slots-ref (get-slots method) *sm-%function-index*)
1803         (method-function method))))
1804 (defun safe-method-qualifiers (method)
1805   (let ((standard-method-classes
1806          (list *the-class-standard-method*
1807                *the-class-standard-reader-method*
1808                *the-class-standard-writer-method*
1809                *the-class-standard-boundp-method*))
1810         (class (class-of method)))
1811     (if (member class standard-method-classes)
1812         (let ((plist (clos-slots-ref (get-slots method) *sm-plist-index*)))
1813           (getf plist 'qualifiers))
1814         (method-qualifiers method))))
1815
1816 (defun set-arg-info1 (gf arg-info new-method methods was-valid-p first-p)
1817   (let* ((existing-p (and methods (cdr methods) new-method))
1818          (nreq (length (arg-info-metatypes arg-info)))
1819          (metatypes (if existing-p
1820                         (arg-info-metatypes arg-info)
1821                         (make-list nreq)))
1822          (type (if existing-p
1823                    (gf-info-simple-accessor-type arg-info)
1824                    nil)))
1825     (when (arg-info-valid-p arg-info)
1826       (dolist (method (if new-method (list new-method) methods))
1827         (let* ((specializers (if (or (eq *boot-state* 'complete)
1828                                      (not (consp method)))
1829                                  (safe-method-specializers method)
1830                                  (early-method-specializers method t)))
1831                (class (if (or (eq *boot-state* 'complete) (not (consp method)))
1832                           (class-of method)
1833                           (early-method-class method)))
1834                (new-type (when (and class
1835                                     (or (not (eq *boot-state* 'complete))
1836                                         (eq (generic-function-method-combination gf)
1837                                             *standard-method-combination*)))
1838                            (cond ((eq class *the-class-standard-reader-method*)
1839                                   'reader)
1840                                  ((eq class *the-class-standard-writer-method*)
1841                                   'writer)
1842                                  ((eq class *the-class-standard-boundp-method*)
1843                                   'boundp)))))
1844           (setq metatypes (mapcar #'raise-metatype metatypes specializers))
1845           (setq type (cond ((null type) new-type)
1846                            ((eq type new-type) type)
1847                            (t nil)))))
1848       (setf (arg-info-metatypes arg-info) metatypes)
1849       (setf (gf-info-simple-accessor-type arg-info) type)))
1850   (when (or (not was-valid-p) first-p)
1851     (multiple-value-bind (c-a-m-emf std-p)
1852         (if (early-gf-p gf)
1853             (values t t)
1854             (compute-applicable-methods-emf gf))
1855       (setf (gf-info-static-c-a-m-emf arg-info) c-a-m-emf)
1856       (setf (gf-info-c-a-m-emf-std-p arg-info) std-p)
1857       (unless (gf-info-c-a-m-emf-std-p arg-info)
1858         (setf (gf-info-simple-accessor-type arg-info) t))))
1859   (unless was-valid-p
1860     (let ((name (if (eq *boot-state* 'complete)
1861                     (generic-function-name gf)
1862                     (!early-gf-name gf))))
1863       (setf (gf-precompute-dfun-and-emf-p arg-info)
1864             (cond
1865               ((and (consp name)
1866                     (member (car name)
1867                             *internal-pcl-generalized-fun-name-symbols*))
1868                 nil)
1869               (t (let* ((symbol (fun-name-block-name name))
1870                         (package (symbol-package symbol)))
1871                    (and (or (eq package *pcl-package*)
1872                             (memq package (package-use-list *pcl-package*)))
1873                         ;; FIXME: this test will eventually be
1874                         ;; superseded by the *internal-pcl...* test,
1875                         ;; above.  While we are in a process of
1876                         ;; transition, however, it should probably
1877                         ;; remain.
1878                         (not (find #\Space (symbol-name symbol))))))))))
1879   (setf (gf-info-fast-mf-p arg-info)
1880         (or (not (eq *boot-state* 'complete))
1881             (let* ((method-class (generic-function-method-class gf))
1882                    (methods (compute-applicable-methods
1883                              #'make-method-lambda
1884                              (list gf (class-prototype method-class)
1885                                    '(lambda) nil))))
1886               (and methods (null (cdr methods))
1887                    (let ((specls (method-specializers (car methods))))
1888                      (and (classp (car specls))
1889                           (eq 'standard-generic-function
1890                               (class-name (car specls)))
1891                           (classp (cadr specls))
1892                           (eq 'standard-method
1893                               (class-name (cadr specls)))))))))
1894   arg-info)
1895
1896 ;;; This is the early definition of ENSURE-GENERIC-FUNCTION-USING-CLASS.
1897 ;;;
1898 ;;; The STATIC-SLOTS field of the funcallable instances used as early
1899 ;;; generic functions is used to store the early methods and early
1900 ;;; discriminator code for the early generic function. The static
1901 ;;; slots field of the fins contains a list whose:
1902 ;;;    CAR    -   a list of the early methods on this early gf
1903 ;;;    CADR   -   the early discriminator code for this method
1904 (defun ensure-generic-function-using-class (existing spec &rest keys
1905                                             &key (lambda-list nil
1906                                                               lambda-list-p)
1907                                             argument-precedence-order
1908                                             source-location
1909                                             &allow-other-keys)
1910   (declare (ignore keys))
1911   (cond ((and existing (early-gf-p existing))
1912          (when lambda-list-p
1913            (set-arg-info existing :lambda-list lambda-list))
1914          existing)
1915         ((assoc spec *!generic-function-fixups* :test #'equal)
1916          (if existing
1917              (make-early-gf spec lambda-list lambda-list-p existing
1918                             argument-precedence-order source-location)
1919              (error "The function ~S is not already defined." spec)))
1920         (existing
1921          (error "~S should be on the list ~S."
1922                 spec
1923                 '*!generic-function-fixups*))
1924         (t
1925          (pushnew spec *!early-generic-functions* :test #'equal)
1926          (make-early-gf spec lambda-list lambda-list-p nil
1927                         argument-precedence-order source-location))))
1928
1929 (defun make-early-gf (spec &optional lambda-list lambda-list-p
1930                       function argument-precedence-order source-location)
1931   (let ((fin (allocate-funcallable-instance *sgf-wrapper* *sgf-slots-init*)))
1932     (set-funcallable-instance-function
1933      fin
1934      (or function
1935          (if (eq spec 'print-object)
1936              #'(lambda (instance stream)
1937                  (print-unreadable-object (instance stream :identity t)
1938                    (format stream "std-instance")))
1939              #'(lambda (&rest args)
1940                  (declare (ignore args))
1941                  (error "The function of the funcallable-instance ~S~
1942                          has not been set." fin)))))
1943     (setf (gdefinition spec) fin)
1944     (!bootstrap-set-slot 'standard-generic-function fin 'name spec)
1945     (!bootstrap-set-slot 'standard-generic-function
1946                          fin
1947                          'source
1948                          source-location)
1949     (set-fun-name fin spec)
1950     (let ((arg-info (make-arg-info)))
1951       (setf (early-gf-arg-info fin) arg-info)
1952       (when lambda-list-p
1953         (proclaim (defgeneric-declaration spec lambda-list))
1954         (if argument-precedence-order
1955             (set-arg-info fin
1956                           :lambda-list lambda-list
1957                           :argument-precedence-order argument-precedence-order)
1958             (set-arg-info fin :lambda-list lambda-list))))
1959     fin))
1960
1961 (defun safe-gf-dfun-state (generic-function)
1962   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1963       (clos-slots-ref (get-slots generic-function) *sgf-dfun-state-index*)
1964       (gf-dfun-state generic-function)))
1965 (defun (setf safe-gf-dfun-state) (new-value generic-function)
1966   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1967       (setf (clos-slots-ref (get-slots generic-function)
1968                             *sgf-dfun-state-index*)
1969             new-value)
1970       (setf (gf-dfun-state generic-function) new-value)))
1971
1972 (defun set-dfun (gf &optional dfun cache info)
1973   (when cache
1974     (setf (cache-owner cache) gf))
1975   (let ((new-state (if (and dfun (or cache info))
1976                        (list* dfun cache info)
1977                        dfun)))
1978     (if (eq *boot-state* 'complete)
1979         (setf (safe-gf-dfun-state gf) new-state)
1980         (setf (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*)
1981               new-state)))
1982   dfun)
1983
1984 (defun gf-dfun-cache (gf)
1985   (let ((state (if (eq *boot-state* 'complete)
1986                    (safe-gf-dfun-state gf)
1987                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1988     (typecase state
1989       (function nil)
1990       (cons (cadr state)))))
1991
1992 (defun gf-dfun-info (gf)
1993   (let ((state (if (eq *boot-state* 'complete)
1994                    (safe-gf-dfun-state gf)
1995                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1996     (typecase state
1997       (function nil)
1998       (cons (cddr state)))))
1999
2000 (defvar *sgf-name-index*
2001   (!bootstrap-slot-index 'standard-generic-function 'name))
2002
2003 (defun !early-gf-name (gf)
2004   (clos-slots-ref (get-slots gf) *sgf-name-index*))
2005
2006 (defun gf-lambda-list (gf)
2007   (let ((arg-info (if (eq *boot-state* 'complete)
2008                       (gf-arg-info gf)
2009                       (early-gf-arg-info gf))))
2010     (if (eq :no-lambda-list (arg-info-lambda-list arg-info))
2011         (let ((methods (if (eq *boot-state* 'complete)
2012                            (generic-function-methods gf)
2013                            (early-gf-methods gf))))
2014           (if (null methods)
2015               (progn
2016                 (warn "no way to determine the lambda list for ~S" gf)
2017                 nil)
2018               (let* ((method (car (last methods)))
2019                      (ll (if (consp method)
2020                              (early-method-lambda-list method)
2021                              (method-lambda-list method))))
2022                 (create-gf-lambda-list ll))))
2023         (arg-info-lambda-list arg-info))))
2024
2025 (defmacro real-ensure-gf-internal (gf-class all-keys env)
2026   `(progn
2027      (cond ((symbolp ,gf-class)
2028             (setq ,gf-class (find-class ,gf-class t ,env)))
2029            ((classp ,gf-class))
2030            (t
2031             (error "The :GENERIC-FUNCTION-CLASS argument (~S) was neither a~%~
2032                     class nor a symbol that names a class."
2033                    ,gf-class)))
2034      (remf ,all-keys :generic-function-class)
2035      (remf ,all-keys :environment)
2036      (let ((combin (getf ,all-keys :method-combination '.shes-not-there.)))
2037        (unless (eq combin '.shes-not-there.)
2038          (setf (getf ,all-keys :method-combination)
2039                (find-method-combination (class-prototype ,gf-class)
2040                                         (car combin)
2041                                         (cdr combin)))))
2042     (let ((method-class (getf ,all-keys :method-class '.shes-not-there.)))
2043       (unless (eq method-class '.shes-not-there.)
2044         (setf (getf ,all-keys :method-class)
2045               (cond ((classp method-class)
2046                      method-class)
2047                     (t (find-class method-class t ,env))))))))
2048
2049 (defun real-ensure-gf-using-class--generic-function
2050        (existing
2051         fun-name
2052         &rest all-keys
2053         &key environment (lambda-list nil lambda-list-p)
2054              (generic-function-class 'standard-generic-function gf-class-p)
2055         &allow-other-keys)
2056   (real-ensure-gf-internal generic-function-class all-keys environment)
2057   (unless (or (null gf-class-p)
2058               (eq (class-of existing) generic-function-class))
2059     (change-class existing generic-function-class))
2060   (prog1
2061       (apply #'reinitialize-instance existing all-keys)
2062     (when lambda-list-p
2063       (proclaim (defgeneric-declaration fun-name lambda-list)))))
2064
2065 (defun real-ensure-gf-using-class--null
2066        (existing
2067         fun-name
2068         &rest all-keys
2069         &key environment (lambda-list nil lambda-list-p)
2070              (generic-function-class 'standard-generic-function)
2071         &allow-other-keys)
2072   (declare (ignore existing))
2073   (real-ensure-gf-internal generic-function-class all-keys environment)
2074   (prog1
2075       (setf (gdefinition fun-name)
2076             (apply #'make-instance generic-function-class
2077                    :name fun-name all-keys))
2078     (when lambda-list-p
2079       (proclaim (defgeneric-declaration fun-name lambda-list)))))
2080 \f
2081 (defun safe-gf-arg-info (generic-function)
2082   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2083       (clos-slots-ref (fsc-instance-slots generic-function)
2084                       *sgf-arg-info-index*)
2085       (gf-arg-info generic-function)))
2086
2087 ;;; FIXME: this function took on a slightly greater role than it
2088 ;;; previously had around 2005-11-02, when CSR fixed the bug whereby
2089 ;;; having more than one subclass of standard-generic-function caused
2090 ;;; the whole system to die horribly through a metacircle in
2091 ;;; GF-ARG-INFO.  The fix is to be slightly more disciplined about
2092 ;;; calling accessor methods -- we call GET-GENERIC-FUN-INFO when
2093 ;;; computing discriminating functions, so we need to be careful about
2094 ;;; having a base case for the recursion, and we provide that with the
2095 ;;; STANDARD-GENERIC-FUNCTION case below.  However, we are not (yet)
2096 ;;; as disciplined as CLISP's CLOS/MOP, and it would be nice to get to
2097 ;;; that stage, where all potentially dangerous cases are enumerated
2098 ;;; and stopped.  -- CSR, 2005-11-02.
2099 (defun get-generic-fun-info (gf)
2100   ;; values   nreq applyp metatypes nkeys arg-info
2101   (multiple-value-bind (applyp metatypes arg-info)
2102       (let* ((arg-info (if (early-gf-p gf)
2103                            (early-gf-arg-info gf)
2104                            (safe-gf-arg-info gf)))
2105              (metatypes (arg-info-metatypes arg-info)))
2106         (values (arg-info-applyp arg-info)
2107                 metatypes
2108                 arg-info))
2109     (values (length metatypes) applyp metatypes
2110             (count-if (lambda (x) (neq x t)) metatypes)
2111             arg-info)))
2112
2113 (defun early-make-a-method (class qualifiers arglist specializers initargs doc
2114                             &optional slot-name)
2115   (initialize-method-function initargs)
2116   (let ((parsed ())
2117         (unparsed ()))
2118     ;; Figure out whether we got class objects or class names as the
2119     ;; specializers and set parsed and unparsed appropriately. If we
2120     ;; got class objects, then we can compute unparsed, but if we got
2121     ;; class names we don't try to compute parsed.
2122     ;;
2123     ;; Note that the use of not symbolp in this call to every should be
2124     ;; read as 'classp' we can't use classp itself because it doesn't
2125     ;; exist yet.
2126     (if (every (lambda (s) (not (symbolp s))) specializers)
2127         (setq parsed specializers
2128               unparsed (mapcar (lambda (s)
2129                                  (if (eq s t) t (class-name s)))
2130                                specializers))
2131         (setq unparsed specializers
2132               parsed ()))
2133     (list :early-method           ;This is an early method dammit!
2134
2135           (getf initargs :function)
2136           (getf initargs :fast-function)
2137
2138           parsed                  ;The parsed specializers. This is used
2139                                   ;by early-method-specializers to cache
2140                                   ;the parse. Note that this only comes
2141                                   ;into play when there is more than one
2142                                   ;early method on an early gf.
2143
2144           (list class        ;A list to which real-make-a-method
2145                 qualifiers      ;can be applied to make a real method
2146                 arglist    ;corresponding to this early one.
2147                 unparsed
2148                 initargs
2149                 doc
2150                 slot-name))))
2151
2152 (defun real-make-a-method
2153        (class qualifiers lambda-list specializers initargs doc
2154         &optional slot-name)
2155   (setq specializers (parse-specializers specializers))
2156   (apply #'make-instance class
2157          :qualifiers qualifiers
2158          :lambda-list lambda-list
2159          :specializers specializers
2160          :documentation doc
2161          :slot-name slot-name
2162          :allow-other-keys t
2163          initargs))
2164
2165 (defun early-method-function (early-method)
2166   (values (cadr early-method) (caddr early-method)))
2167
2168 (defun early-method-class (early-method)
2169   (find-class (car (fifth early-method))))
2170
2171 (defun early-method-standard-accessor-p (early-method)
2172   (let ((class (first (fifth early-method))))
2173     (or (eq class 'standard-reader-method)
2174         (eq class 'standard-writer-method)
2175         (eq class 'standard-boundp-method))))
2176
2177 (defun early-method-standard-accessor-slot-name (early-method)
2178   (seventh (fifth early-method)))
2179
2180 ;;; Fetch the specializers of an early method. This is basically just
2181 ;;; a simple accessor except that when the second argument is t, this
2182 ;;; converts the specializers from symbols into class objects. The
2183 ;;; class objects are cached in the early method, this makes
2184 ;;; bootstrapping faster because the class objects only have to be
2185 ;;; computed once.
2186 ;;;
2187 ;;; NOTE:
2188 ;;;  The second argument should only be passed as T by
2189 ;;;  early-lookup-method. This is to implement the rule that only when
2190 ;;;  there is more than one early method on a generic function is the
2191 ;;;  conversion from class names to class objects done. This
2192 ;;;  corresponds to the fact that we are only allowed to have one
2193 ;;;  method on any generic function up until the time classes exist.
2194 (defun early-method-specializers (early-method &optional objectsp)
2195   (if (and (listp early-method)
2196            (eq (car early-method) :early-method))
2197       (cond ((eq objectsp t)
2198              (or (fourth early-method)
2199                  (setf (fourth early-method)
2200                        (mapcar #'find-class (cadddr (fifth early-method))))))
2201             (t
2202              (cadddr (fifth early-method))))
2203       (error "~S is not an early-method." early-method)))
2204
2205 (defun early-method-qualifiers (early-method)
2206   (cadr (fifth early-method)))
2207
2208 (defun early-method-lambda-list (early-method)
2209   (caddr (fifth early-method)))
2210
2211 (defun early-add-named-method (generic-function-name
2212                                qualifiers
2213                                specializers
2214                                arglist
2215                                &rest initargs)
2216   (let* ((gf (ensure-generic-function generic-function-name))
2217          (existing
2218            (dolist (m (early-gf-methods gf))
2219              (when (and (equal (early-method-specializers m) specializers)
2220                         (equal (early-method-qualifiers m) qualifiers))
2221                (return m))))
2222          (new (make-a-method 'standard-method
2223                              qualifiers
2224                              arglist
2225                              specializers
2226                              initargs
2227                              ())))
2228     (when existing (remove-method gf existing))
2229     (add-method gf new)))
2230
2231 ;;; This is the early version of ADD-METHOD. Later this will become a
2232 ;;; generic function. See !FIX-EARLY-GENERIC-FUNCTIONS which has
2233 ;;; special knowledge about ADD-METHOD.
2234 (defun add-method (generic-function method)
2235   (when (not (fsc-instance-p generic-function))
2236     (error "Early ADD-METHOD didn't get a funcallable instance."))
2237   (when (not (and (listp method) (eq (car method) :early-method)))
2238     (error "Early ADD-METHOD didn't get an early method."))
2239   (push method (early-gf-methods generic-function))
2240   (set-arg-info generic-function :new-method method)
2241   (unless (assoc (!early-gf-name generic-function)
2242                  *!generic-function-fixups*
2243                  :test #'equal)
2244     (update-dfun generic-function)))
2245
2246 ;;; This is the early version of REMOVE-METHOD. See comments on
2247 ;;; the early version of ADD-METHOD.
2248 (defun remove-method (generic-function method)
2249   (when (not (fsc-instance-p generic-function))
2250     (error "An early remove-method didn't get a funcallable instance."))
2251   (when (not (and (listp method) (eq (car method) :early-method)))
2252     (error "An early remove-method didn't get an early method."))
2253   (setf (early-gf-methods generic-function)
2254         (remove method (early-gf-methods generic-function)))
2255   (set-arg-info generic-function)
2256   (unless (assoc (!early-gf-name generic-function)
2257                  *!generic-function-fixups*
2258                  :test #'equal)
2259     (update-dfun generic-function)))
2260
2261 ;;; This is the early version of GET-METHOD. See comments on the early
2262 ;;; version of ADD-METHOD.
2263 (defun get-method (generic-function qualifiers specializers
2264                                     &optional (errorp t))
2265   (if (early-gf-p generic-function)
2266       (or (dolist (m (early-gf-methods generic-function))
2267             (when (and (or (equal (early-method-specializers m nil)
2268                                   specializers)
2269                            (equal (early-method-specializers m t)
2270                                   specializers))
2271                        (equal (early-method-qualifiers m) qualifiers))
2272               (return m)))
2273           (if errorp
2274               (error "can't get early method")
2275               nil))
2276       (real-get-method generic-function qualifiers specializers errorp)))
2277
2278 (defun !fix-early-generic-functions ()
2279   (let ((accessors nil))
2280     ;; Rearrange *!EARLY-GENERIC-FUNCTIONS* to speed up
2281     ;; FIX-EARLY-GENERIC-FUNCTIONS.
2282     (dolist (early-gf-spec *!early-generic-functions*)
2283       (when (every #'early-method-standard-accessor-p
2284                    (early-gf-methods (gdefinition early-gf-spec)))
2285         (push early-gf-spec accessors)))
2286     (dolist (spec (nconc accessors
2287                          '(accessor-method-slot-name
2288                            generic-function-methods
2289                            method-specializers
2290                            specializerp
2291                            specializer-type
2292                            specializer-class
2293                            slot-definition-location
2294                            slot-definition-name
2295                            class-slots
2296                            gf-arg-info
2297                            class-precedence-list
2298                            slot-boundp-using-class
2299                            (setf slot-value-using-class)
2300                            slot-value-using-class
2301                            structure-class-p
2302                            standard-class-p
2303                            funcallable-standard-class-p
2304                            specializerp)))
2305       (/show spec)
2306       (setq *!early-generic-functions*
2307             (cons spec
2308                   (delete spec *!early-generic-functions* :test #'equal))))
2309
2310     (dolist (early-gf-spec *!early-generic-functions*)
2311       (/show early-gf-spec)
2312       (let* ((gf (gdefinition early-gf-spec))
2313              (methods (mapcar (lambda (early-method)
2314                                 (let ((args (copy-list (fifth
2315                                                         early-method))))
2316                                   (setf (fourth args)
2317                                         (early-method-specializers
2318                                          early-method t))
2319                                   (apply #'real-make-a-method args)))
2320                               (early-gf-methods gf))))
2321         (setf (generic-function-method-class gf) *the-class-standard-method*)
2322         (setf (generic-function-method-combination gf)
2323               *standard-method-combination*)
2324         (set-methods gf methods)))
2325
2326     (dolist (fn *!early-functions*)
2327       (/show fn)
2328       (setf (gdefinition (car fn)) (fdefinition (caddr fn))))
2329
2330     (dolist (fixup *!generic-function-fixups*)
2331       (/show fixup)
2332       (let* ((fspec (car fixup))
2333              (gf (gdefinition fspec))
2334              (methods (mapcar (lambda (method)
2335                                 (let* ((lambda-list (first method))
2336                                        (specializers (second method))
2337                                        (method-fn-name (third method))
2338                                        (fn-name (or method-fn-name fspec))
2339                                        (fn (fdefinition fn-name))
2340                                        (initargs
2341                                         (list :function
2342                                               (set-fun-name
2343                                                (lambda (args next-methods)
2344                                                  (declare (ignore
2345                                                            next-methods))
2346                                                  (apply fn args))
2347                                                `(call ,fn-name)))))
2348                                   (declare (type function fn))
2349                                   (make-a-method 'standard-method
2350                                                  ()
2351                                                  lambda-list
2352                                                  specializers
2353                                                  initargs
2354                                                  nil)))
2355                               (cdr fixup))))
2356         (setf (generic-function-method-class gf) *the-class-standard-method*)
2357         (setf (generic-function-method-combination gf)
2358               *standard-method-combination*)
2359         (set-methods gf methods))))
2360   (/show "leaving !FIX-EARLY-GENERIC-FUNCTIONS"))
2361 \f
2362 ;;; PARSE-DEFMETHOD is used by DEFMETHOD to parse the &REST argument
2363 ;;; into the 'real' arguments. This is where the syntax of DEFMETHOD
2364 ;;; is really implemented.
2365 (defun parse-defmethod (cdr-of-form)
2366   (declare (list cdr-of-form))
2367   (let ((name (pop cdr-of-form))
2368         (qualifiers ())
2369         (spec-ll ()))
2370     (loop (if (and (car cdr-of-form) (atom (car cdr-of-form)))
2371               (push (pop cdr-of-form) qualifiers)
2372               (return (setq qualifiers (nreverse qualifiers)))))
2373     (setq spec-ll (pop cdr-of-form))
2374     (values name qualifiers spec-ll cdr-of-form)))
2375
2376 (defun parse-specializers (specializers)
2377   (declare (list specializers))
2378   (flet ((parse (spec)
2379            (let ((result (specializer-from-type spec)))
2380              (if (specializerp result)
2381                  result
2382                  (if (symbolp spec)
2383                      (error "~S was used as a specializer,~%~
2384                              but is not the name of a class."
2385                             spec)
2386                      (error "~S is not a legal specializer." spec))))))
2387     (mapcar #'parse specializers)))
2388
2389 (defun unparse-specializers (specializers-or-method)
2390   (if (listp specializers-or-method)
2391       (flet ((unparse (spec)
2392                (if (specializerp spec)
2393                    (let ((type (specializer-type spec)))
2394                      (if (and (consp type)
2395                               (eq (car type) 'class))
2396                          (let* ((class (cadr type))
2397                                 (class-name (class-name class)))
2398                            (if (eq class (find-class class-name nil))
2399                                class-name
2400                                type))
2401                          type))
2402                    (error "~S is not a legal specializer." spec))))
2403         (mapcar #'unparse specializers-or-method))
2404       (unparse-specializers (method-specializers specializers-or-method))))
2405
2406 (defun parse-method-or-spec (spec &optional (errorp t))
2407   (let (gf method name temp)
2408     (if (method-p spec)
2409         (setq method spec
2410               gf (method-generic-function method)
2411               temp (and gf (generic-function-name gf))
2412               name (if temp
2413                        (make-method-spec temp
2414                                          (method-qualifiers method)
2415                                          (unparse-specializers
2416                                           (method-specializers method)))
2417                        (make-symbol (format nil "~S" method))))
2418         (multiple-value-bind (gf-spec quals specls)
2419             (parse-defmethod spec)
2420           (and (setq gf (and (or errorp (fboundp gf-spec))
2421                              (gdefinition gf-spec)))
2422                (let ((nreq (compute-discriminating-function-arglist-info gf)))
2423                  (setq specls (append (parse-specializers specls)
2424                                       (make-list (- nreq (length specls))
2425                                                  :initial-element
2426                                                  *the-class-t*)))
2427                  (and
2428                    (setq method (get-method gf quals specls errorp))
2429                    (setq name
2430                          (make-method-spec
2431                           gf-spec quals (unparse-specializers specls))))))))
2432     (values gf method name)))
2433 \f
2434 (defun extract-parameters (specialized-lambda-list)
2435   (multiple-value-bind (parameters ignore1 ignore2)
2436       (parse-specialized-lambda-list specialized-lambda-list)
2437     (declare (ignore ignore1 ignore2))
2438     parameters))
2439
2440 (defun extract-lambda-list (specialized-lambda-list)
2441   (multiple-value-bind (ignore1 lambda-list ignore2)
2442       (parse-specialized-lambda-list specialized-lambda-list)
2443     (declare (ignore ignore1 ignore2))
2444     lambda-list))
2445
2446 (defun extract-specializer-names (specialized-lambda-list)
2447   (multiple-value-bind (ignore1 ignore2 specializers)
2448       (parse-specialized-lambda-list specialized-lambda-list)
2449     (declare (ignore ignore1 ignore2))
2450     specializers))
2451
2452 (defun extract-required-parameters (specialized-lambda-list)
2453   (multiple-value-bind (ignore1 ignore2 ignore3 required-parameters)
2454       (parse-specialized-lambda-list specialized-lambda-list)
2455     (declare (ignore ignore1 ignore2 ignore3))
2456     required-parameters))
2457
2458 (define-condition specialized-lambda-list-error
2459     (reference-condition simple-program-error)
2460   ()
2461   (:default-initargs :references (list '(:ansi-cl :section (3 4 3)))))
2462
2463 (defun parse-specialized-lambda-list
2464     (arglist
2465      &optional supplied-keywords (allowed-keywords '(&optional &rest &key &aux))
2466      &aux (specialized-lambda-list-keywords
2467            '(&optional &rest &key &allow-other-keys &aux)))
2468   (let ((arg (car arglist)))
2469     (cond ((null arglist) (values nil nil nil nil))
2470           ((eq arg '&aux)
2471            (values nil arglist nil nil))
2472           ((memq arg lambda-list-keywords)
2473            ;; non-standard lambda-list-keywords are errors.
2474            (unless (memq arg specialized-lambda-list-keywords)
2475              (error 'specialized-lambda-list-error
2476                     :format-control "unknown specialized-lambda-list ~
2477                                      keyword ~S~%"
2478                     :format-arguments (list arg)))
2479            ;; no multiple &rest x &rest bla specifying
2480            (when (memq arg supplied-keywords)
2481              (error 'specialized-lambda-list-error
2482                     :format-control "multiple occurrence of ~
2483                                      specialized-lambda-list keyword ~S~%"
2484                     :format-arguments (list arg)))
2485            ;; And no placing &key in front of &optional, either.
2486            (unless (memq arg allowed-keywords)
2487              (error 'specialized-lambda-list-error
2488                     :format-control "misplaced specialized-lambda-list ~
2489                                      keyword ~S~%"
2490                     :format-arguments (list arg)))
2491            ;; When we are at a lambda-list keyword, the parameters
2492            ;; don't include the lambda-list keyword; the lambda-list
2493            ;; does include the lambda-list keyword; and no
2494            ;; specializers are allowed to follow the lambda-list
2495            ;; keywords (at least for now).
2496            (multiple-value-bind (parameters lambda-list)
2497                (parse-specialized-lambda-list (cdr arglist)
2498                                               (cons arg supplied-keywords)
2499                                               (if (eq arg '&key)
2500                                                   (cons '&allow-other-keys
2501                                                         (cdr (member arg allowed-keywords)))
2502                                                 (cdr (member arg allowed-keywords))))
2503              (when (and (eq arg '&rest)
2504                         (or (null lambda-list)
2505                             (memq (car lambda-list)
2506                                   specialized-lambda-list-keywords)
2507                             (not (or (null (cadr lambda-list))
2508                                      (memq (cadr lambda-list)
2509                                            specialized-lambda-list-keywords)))))
2510                (error 'specialized-lambda-list-error
2511                       :format-control
2512                       "in a specialized-lambda-list, excactly one ~
2513                        variable must follow &REST.~%"
2514                       :format-arguments nil))
2515              (values parameters
2516                      (cons arg lambda-list)
2517                      ()
2518                      ())))
2519           (supplied-keywords
2520            ;; After a lambda-list keyword there can be no specializers.
2521            (multiple-value-bind (parameters lambda-list)
2522                (parse-specialized-lambda-list (cdr arglist)
2523                                               supplied-keywords
2524                                               allowed-keywords)
2525              (values (cons (if (listp arg) (car arg) arg) parameters)
2526                      (cons arg lambda-list)
2527                      ()
2528                      ())))
2529           (t
2530            (multiple-value-bind (parameters lambda-list specializers required)
2531                (parse-specialized-lambda-list (cdr arglist))
2532              (values (cons (if (listp arg) (car arg) arg) parameters)
2533                      (cons (if (listp arg) (car arg) arg) lambda-list)
2534                      (cons (if (listp arg) (cadr arg) t) specializers)
2535                      (cons (if (listp arg) (car arg) arg) required)))))))
2536 \f
2537 (setq *boot-state* 'early)
2538 \f
2539 ;;; FIXME: In here there was a #-CMU definition of SYMBOL-MACROLET
2540 ;;; which used %WALKER stuff. That suggests to me that maybe the code
2541 ;;; walker stuff was only used for implementing stuff like that; maybe
2542 ;;; it's not needed any more? Hunt down what it was used for and see.
2543
2544 (defmacro with-slots (slots instance &body body)
2545   (let ((in (gensym)))
2546     `(let ((,in ,instance))
2547        (declare (ignorable ,in))
2548        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2549                              (third instance)
2550                              instance)))
2551            (and (symbolp instance)
2552                 `((declare (%variable-rebinding ,in ,instance)))))
2553        ,in
2554        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2555                                    (let ((var-name
2556                                           (if (symbolp slot-entry)
2557                                               slot-entry
2558                                               (car slot-entry)))
2559                                          (slot-name
2560                                           (if (symbolp slot-entry)
2561                                               slot-entry
2562                                               (cadr slot-entry))))
2563                                      `(,var-name
2564                                        (slot-value ,in ',slot-name))))
2565                                  slots)
2566                         ,@body))))
2567
2568 (defmacro with-accessors (slots instance &body body)
2569   (let ((in (gensym)))
2570     `(let ((,in ,instance))
2571        (declare (ignorable ,in))
2572        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2573                              (third instance)
2574                              instance)))
2575            (and (symbolp instance)
2576                 `((declare (%variable-rebinding ,in ,instance)))))
2577        ,in
2578        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2579                                    (let ((var-name (car slot-entry))
2580                                          (accessor-name (cadr slot-entry)))
2581                                      `(,var-name (,accessor-name ,in))))
2582                                  slots)
2583           ,@body))))