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
 393 (defun interned-symbol-p (x)
 394   (and (symbolp x) (symbol-package x)))
 395
 396 (defun make-defmethod-form
 397     (name qualifiers specializers unspecialized-lambda-list
 398      method-class-name initargs-form)
 399   (let (fn
 400         fn-lambda)
 401     (if (and (interned-symbol-p (fun-name-block-name name))
 402              (every #'interned-symbol-p qualifiers)
 403              (every (lambda (s)
 404                       (if (consp s)
 405                           (and (eq (car s) 'eql)
 406                                (constantp (cadr s))
 407                                (let ((sv (constant-form-value (cadr s))))
 408                                  (or (interned-symbol-p sv)
 409                                      (integerp sv)
 410                                      (and (characterp sv)
 411                                           (standard-char-p sv)))))
 412                           (interned-symbol-p s)))
 413                     specializers)
 414              (consp initargs-form)
 415              (eq (car initargs-form) 'list*)
 416              (memq (cadr initargs-form) '(:function :fast-function))
 417              (consp (setq fn (caddr initargs-form)))
 418              (eq (car fn) 'function)
 419              (consp (setq fn-lambda (cadr fn)))
 420              (eq (car fn-lambda) 'lambda))
 421         (let* ((specls (mapcar (lambda (specl)
 422                                  (if (consp specl)
 423                                      `(,(car specl) ,(eval (cadr specl)))
 424                                    specl))
 425                                specializers))
 426                (mname `(,(if (eq (cadr initargs-form) :function)
 427                              'slow-method 'fast-method)
 428                         ,name ,@qualifiers ,specls)))
 429           `(progn
 430              (defun ,mname ,(cadr fn-lambda)
 431                ,@(cddr fn-lambda))
 432              ,(make-defmethod-form-internal
 433                name qualifiers `',specls
 434                unspecialized-lambda-list method-class-name
 435                `(list* ,(cadr initargs-form)
 436                        #',mname
 437                        ,@(cdddr initargs-form)))))
 438         (make-defmethod-form-internal
 439          name qualifiers
 440          `(list ,@(mapcar (lambda (specializer)
 441                             (if (consp specializer)
 442                                 ``(,',(car specializer)
 443                                       ,,(cadr specializer))
 444                                 `',specializer))
 445                           specializers))
 446          unspecialized-lambda-list
 447          method-class-name
 448          initargs-form))))
 449
 450 (defun make-defmethod-form-internal
 451     (name qualifiers specializers-form unspecialized-lambda-list
 452      method-class-name initargs-form)
 453   `(load-defmethod
 454     ',method-class-name
 455     ',name
 456     ',qualifiers
 457     ,specializers-form
 458     ',unspecialized-lambda-list
 459     ,initargs-form
 460     (sb-c:source-location)))
 461
 462 (defmacro make-method-function (method-lambda &environment env)
 463   (make-method-function-internal method-lambda env))
 464
 465 (defun make-method-function-internal (method-lambda &optional env)
 466   (multiple-value-bind (proto-gf proto-method)
 467       (prototypes-for-make-method-lambda nil)
 468     (multiple-value-bind (method-function-lambda initargs)
 469         (make-method-lambda proto-gf proto-method method-lambda env)
 470       (make-method-initargs-form proto-gf
 471                                  proto-method
 472                                  method-function-lambda
 473                                  initargs
 474                                  env))))
 475
 476 (defun add-method-declarations (name qualifiers lambda-list body env)
 477   (declare (ignore env))
 478   (multiple-value-bind (parameters unspecialized-lambda-list specializers)
 479       (parse-specialized-lambda-list lambda-list)
 480     (multiple-value-bind (real-body declarations documentation)
 481         (parse-body body)
 482       (values `(lambda ,unspecialized-lambda-list
 483                  ,@(when documentation `(,documentation))
 484                  ;; (Old PCL code used a somewhat different style of
 485                  ;; list for %METHOD-NAME values. Our names use
 486                  ;; ,@QUALIFIERS instead of ,QUALIFIERS so that the
 487                  ;; method names look more like what you see in a
 488                  ;; DEFMETHOD form.)
 489                  ;;
 490                  ;; FIXME: As of sbcl-0.7.0.6, code elsewhere, at
 491                  ;; least the code to set up named BLOCKs around the
 492                  ;; bodies of methods, depends on the function's base
 493                  ;; name being the first element of the %METHOD-NAME
 494                  ;; list. It would be good to remove this dependency,
 495                  ;; perhaps by building the BLOCK here, or by using
 496                  ;; another declaration (e.g. %BLOCK-NAME), so that
 497                  ;; our method debug names are free to have any format,
 498                  ;; e.g. (:METHOD PRINT-OBJECT :AROUND (CLOWN T)).
 499                  ;;
 500                  ;; Further, as of sbcl-0.7.9.10, the code to
 501                  ;; implement NO-NEXT-METHOD is coupled to the form of
 502                  ;; this declaration; see the definition of
 503                  ;; CALL-NO-NEXT-METHOD (and the passing of
 504                  ;; METHOD-NAME-DECLARATION arguments around the
 505                  ;; various CALL-NEXT-METHOD logic).
 506                  (declare (%method-name (,name
 507                                          ,@qualifiers
 508                                          ,specializers)))
 509                  (declare (%method-lambda-list ,@lambda-list))
 510                  ,@declarations
 511                  ,@real-body)
 512               unspecialized-lambda-list specializers))))
 513
 514 (defun real-make-method-initargs-form (proto-gf proto-method
 515                                        method-lambda initargs env)
 516   (declare (ignore proto-gf proto-method))
 517   (unless (and (consp method-lambda)
 518                (eq (car method-lambda) 'lambda))
 519     (error "The METHOD-LAMBDA argument to MAKE-METHOD-FUNCTION, ~S, ~
 520             is not a lambda form."
 521            method-lambda))
 522   (make-method-initargs-form-internal method-lambda initargs env))
 523
 524 (unless (fboundp 'make-method-initargs-form)
 525   (setf (gdefinition 'make-method-initargs-form)
 526         (symbol-function 'real-make-method-initargs-form)))
 527
 528 (defun real-make-method-lambda (proto-gf proto-method method-lambda env)
 529   (declare (ignore proto-gf proto-method))
 530   (make-method-lambda-internal method-lambda env))
 531
 532 ;;; a helper function for creating Python-friendly type declarations
 533 ;;; in DEFMETHOD forms
 534 (defun parameter-specializer-declaration-in-defmethod (parameter specializer)
 535   (cond ((and (consp specializer)
 536               (eq (car specializer) 'eql))
 537          ;; KLUDGE: ANSI, in its wisdom, says that
 538          ;; EQL-SPECIALIZER-FORMs in EQL specializers are evaluated at
 539          ;; DEFMETHOD expansion time. Thus, although one might think
 540          ;; that in
 541          ;;   (DEFMETHOD FOO ((X PACKAGE)
 542          ;;                   (Y (EQL 12))
 543          ;;      ..))
 544          ;; the PACKAGE and (EQL 12) forms are both parallel type
 545          ;; names, they're not, as is made clear when you do
 546          ;;   (DEFMETHOD FOO ((X PACKAGE)
 547          ;;                   (Y (EQL 'BAR)))
 548          ;;     ..)
 549          ;; where Y needs to be a symbol named "BAR", not some cons
 550          ;; made by (CONS 'QUOTE 'BAR). I.e. when the
 551          ;; EQL-SPECIALIZER-FORM is (EQL 'X), it requires an argument
 552          ;; to be of type (EQL X). It'd be easy to transform one to
 553          ;; the other, but it'd be somewhat messier to do so while
 554          ;; ensuring that the EQL-SPECIALIZER-FORM is only EVAL'd
 555          ;; once. (The new code wouldn't be messy, but it'd require a
 556          ;; big transformation of the old code.) So instead we punt.
 557          ;; -- WHN 20000610
 558          '(ignorable))
 559         ((member specializer
 560                  ;; KLUDGE: For some low-level implementation
 561                  ;; classes, perhaps because of some problems related
 562                  ;; to the incomplete integration of PCL into SBCL's
 563                  ;; type system, some specializer classes can't be
 564                  ;; declared as argument types. E.g.
 565                  ;;   (DEFMETHOD FOO ((X SLOT-OBJECT))
 566                  ;;     (DECLARE (TYPE SLOT-OBJECT X))
 567                  ;;     ..)
 568                  ;; loses when
 569                  ;;   (DEFSTRUCT BAR A B)
 570                  ;;   (FOO (MAKE-BAR))
 571                  ;; perhaps because of the way that STRUCTURE-OBJECT
 572                  ;; inherits both from SLOT-OBJECT and from
 573                  ;; SB-KERNEL:INSTANCE. In an effort to sweep such
 574                  ;; problems under the rug, we exclude these problem
 575                  ;; cases by blacklisting them here. -- WHN 2001-01-19
 576                  (list 'slot-object #+nil (find-class 'slot-object)))
 577          '(ignorable))
 578         ((not (eq *boot-state* 'complete))
 579          ;; KLUDGE: PCL, in its wisdom, sometimes calls methods with
 580          ;; types which don't match their specializers. (Specifically,
 581          ;; it calls ENSURE-CLASS-USING-CLASS (T NULL) with a non-NULL
 582          ;; second argument.) Hopefully it only does this kind of
 583          ;; weirdness when bootstrapping.. -- WHN 20000610
 584          '(ignorable))
 585         ((typep specializer 'eql-specializer)
 586          `(type (eql ,(eql-specializer-object specializer)) ,parameter))
 587         ((var-globally-special-p parameter)
 588          ;; KLUDGE: Don't declare types for global special variables
 589          ;; -- our rebinding magic for SETQ cases don't work right
 590          ;; there.
 591          ;;
 592          ;; FIXME: It would be better to detect the SETQ earlier and
 593          ;; skip declarations for specials only when needed, not
 594          ;; always.
 595          ;;
 596          ;; --NS 2004-10-14
 597          '(ignorable))
 598         (t
 599          ;; Otherwise, we can usually make Python very happy.
 600          ;;
 601          ;; KLUDGE: Since INFO doesn't work right for class objects here,
 602          ;; and they are valid specializers, see if the specializer is
 603          ;; a named class, and use the name in that case -- otherwise
 604          ;; the class instance is ok, since info will just return NIL, NIL.
 605          ;;
 606          ;; We still need to deal with the class case too, but at
 607          ;; least #.(find-class 'integer) and integer as equivalent
 608          ;; specializers with this.
 609          (let* ((specializer (if (and (typep specializer 'class)
 610                                       (let ((name (class-name specializer)))
 611                                         (and name (symbolp name)
 612                                              (eq specializer (find-class name nil)))))
 613                                  (class-name specializer)
 614                                  specializer))
 615                 (kind (info :type :kind specializer)))
 616
 617            (flet ((specializer-class ()
 618                     (if (typep specializer 'class)
 619                         specializer
 620                         (find-class specializer nil))))
 621              (ecase kind
 622                ((:primitive) `(type ,specializer ,parameter))
 623                ((:defined)
 624                 (let ((class (specializer-class)))
 625                   ;; CLASS can be null here if the user has erroneously
 626                  ;; tried to use a defined type as a specializer; it
 627                  ;; can be a non-BUILT-IN-CLASS if the user defines a
 628                  ;; type and calls (SETF FIND-CLASS) in a consistent
 629                  ;; way.
 630                  (when (and class (typep class 'built-in-class))
 631                    `(type ,specializer ,parameter))))
 632               ((:instance nil)
 633                (let ((class (specializer-class)))
 634                  (cond
 635                    (class
 636                     (if (typep class '(or built-in-class structure-class))
 637                         `(type ,specializer ,parameter)
 638                         ;; don't declare CLOS classes as parameters;
 639                         ;; it's too expensive.
 640                         '(ignorable)))
 641                    (t
 642                     ;; we can get here, and still not have a failure
 643                     ;; case, by doing MOP programming like (PROGN
 644                     ;; (ENSURE-CLASS 'FOO) (DEFMETHOD BAR ((X FOO))
 645                     ;; ...)).  Best to let the user know we haven't
 646                     ;; been able to extract enough information:
 647                     (style-warn
 648                      "~@<can't find type for presumed class ~S in ~S.~@:>"
 649                      specializer
 650                      'parameter-specializer-declaration-in-defmethod)
 651                     '(ignorable)))))
 652               ((:forthcoming-defclass-type)
 653                '(ignorable))))))))
 654
 655 (defun make-method-lambda-internal (method-lambda &optional env)
 656   (unless (and (consp method-lambda) (eq (car method-lambda) 'lambda))
 657     (error "The METHOD-LAMBDA argument to MAKE-METHOD-LAMBDA, ~S, ~
 658             is not a lambda form."
 659            method-lambda))
 660   (multiple-value-bind (real-body declarations documentation)
 661       (parse-body (cddr method-lambda))
 662     (let* ((name-decl (get-declaration '%method-name declarations))
 663            (sll-decl (get-declaration '%method-lambda-list declarations))
 664            (method-name (when (consp name-decl) (car name-decl)))
 665            (generic-function-name (when method-name (car method-name)))
 666            (specialized-lambda-list (or sll-decl (cadr method-lambda))))
 667       (multiple-value-bind (parameters lambda-list specializers)
 668           (parse-specialized-lambda-list specialized-lambda-list)
 669         (let* ((required-parameters
 670                 (mapcar (lambda (r s) (declare (ignore s)) r)
 671                         parameters
 672                         specializers))
 673                (slots (mapcar #'list required-parameters))
 674                (calls (list nil))
 675                (class-declarations
 676                 `(declare
 677                   ;; These declarations seem to be used by PCL to pass
 678                   ;; information to itself; when I tried to delete 'em
 679                   ;; ca. 0.6.10 it didn't work. I'm not sure how
 680                   ;; they work, but note the (VAR-DECLARATION '%CLASS ..)
 681                   ;; expression in CAN-OPTIMIZE-ACCESS1. -- WHN 2000-12-30
 682                   ,@(remove nil
 683                             (mapcar (lambda (a s) (and (symbolp s)
 684                                                        (neq s t)
 685                                                        `(%class ,a ,s)))
 686                                     parameters
 687                                     specializers))
 688                   ;; These TYPE declarations weren't in the original
 689                   ;; PCL code, but the Python compiler likes them a
 690                   ;; lot. (We're telling the compiler about our
 691                   ;; knowledge of specialized argument types so that
 692                   ;; it can avoid run-time type dispatch overhead,
 693                   ;; which can be a huge win for Python.)
 694                   ;;
 695                   ;; KLUDGE: when I tried moving these to
 696                   ;; ADD-METHOD-DECLARATIONS, things broke.  No idea
 697                   ;; why.  -- CSR, 2004-06-16
 698                   ,@(mapcar #'parameter-specializer-declaration-in-defmethod
 699                             parameters
 700                             specializers)))
 701                (method-lambda
 702                 ;; Remove the documentation string and insert the
 703                 ;; appropriate class declarations. The documentation
 704                 ;; string is removed to make it easy for us to insert
 705                 ;; new declarations later, they will just go after the
 706                 ;; CADR of the method lambda. The class declarations
 707                 ;; are inserted to communicate the class of the method's
 708                 ;; arguments to the code walk.
 709                 `(lambda ,lambda-list
 710                    ;; The default ignorability of method parameters
 711                    ;; doesn't seem to be specified by ANSI. PCL had
 712                    ;; them basically ignorable but was a little
 713                    ;; inconsistent. E.g. even though the two
 714                    ;; method definitions
 715                    ;;   (DEFMETHOD FOO ((X T) (Y T)) "Z")
 716                    ;;   (DEFMETHOD FOO ((X T) Y) "Z")
 717                    ;; are otherwise equivalent, PCL treated Y as
 718                    ;; ignorable in the first definition but not in the
 719                    ;; second definition. We make all required
 720                    ;; parameters ignorable as a way of systematizing
 721                    ;; the old PCL behavior. -- WHN 2000-11-24
 722                    (declare (ignorable ,@required-parameters))
 723                    ,class-declarations
 724                    ,@declarations
 725                    (block ,(fun-name-block-name generic-function-name)
 726                      ,@real-body)))
 727                (constant-value-p (and (null (cdr real-body))
 728                                       (constantp (car real-body))))
 729                (constant-value (and constant-value-p
 730                                     (constant-form-value (car real-body))))
 731                (plist (and constant-value-p
 732                            (or (typep constant-value
 733                                       '(or number character))
 734                                (and (symbolp constant-value)
 735                                     (symbol-package constant-value)))
 736                            (list :constant-value constant-value)))
 737                (applyp (dolist (p lambda-list nil)
 738                          (cond ((memq p '(&optional &rest &key))
 739                                 (return t))
 740                                ((eq p '&aux)
 741                                 (return nil))))))
 742           (multiple-value-bind
 743                 (walked-lambda call-next-method-p closurep
 744                                next-method-p-p setq-p)
 745               (walk-method-lambda method-lambda
 746                                   required-parameters
 747                                   env
 748                                   slots
 749                                   calls)
 750             (multiple-value-bind (walked-lambda-body
 751                                   walked-declarations
 752                                   walked-documentation)
 753                 (parse-body (cddr walked-lambda))
 754               (declare (ignore walked-documentation))
 755               (when (or next-method-p-p call-next-method-p)
 756                 (setq plist (list* :needs-next-methods-p t plist)))
 757               (when (some #'cdr slots)
 758                 (multiple-value-bind (slot-name-lists call-list)
 759                     (slot-name-lists-from-slots slots calls)
 760                   (let ((pv-table-symbol (make-symbol "pv-table")))
 761                     (setq plist
 762                           `(,@(when slot-name-lists
 763                                     `(:slot-name-lists ,slot-name-lists))
 764                               ,@(when call-list
 765                                       `(:call-list ,call-list))
 766                               :pv-table-symbol ,pv-table-symbol
 767                               ,@plist))
 768                     (setq walked-lambda-body
 769                           `((pv-binding (,required-parameters
 770                                          ,slot-name-lists
 771                                          ,pv-table-symbol)
 772                               ,@walked-lambda-body))))))
 773               (when (and (memq '&key lambda-list)
 774                          (not (memq '&allow-other-keys lambda-list)))
 775                 (let ((aux (memq '&aux lambda-list)))
 776                   (setq lambda-list (nconc (ldiff lambda-list aux)
 777                                            (list '&allow-other-keys)
 778                                            aux))))
 779               (values `(lambda (.method-args. .next-methods.)
 780                          (simple-lexical-method-functions
 781                              (,lambda-list .method-args. .next-methods.
 782                                            :call-next-method-p
 783                                            ,call-next-method-p
 784                                            :next-method-p-p ,next-method-p-p
 785                                            :setq-p ,setq-p
 786                                            ;; we need to pass this along
 787                                            ;; so that NO-NEXT-METHOD can
 788                                            ;; be given a suitable METHOD
 789                                            ;; argument; we need the
 790                                            ;; QUALIFIERS and SPECIALIZERS
 791                                            ;; inside the declaration to
 792                                            ;; give to FIND-METHOD.
 793                                            :method-name-declaration ,name-decl
 794                                            :closurep ,closurep
 795                                            :applyp ,applyp)
 796                            ,@walked-declarations
 797                            ,@walked-lambda-body))
 798                       `(,@(when plist
 799                                 `(:plist ,plist))
 800                           ,@(when documentation
 801                                   `(:documentation ,documentation)))))))))))
 802
 803 (unless (fboundp 'make-method-lambda)
 804   (setf (gdefinition 'make-method-lambda)
 805         (symbol-function 'real-make-method-lambda)))
 806
 807 (defmacro simple-lexical-method-functions ((lambda-list
 808                                             method-args
 809                                             next-methods
 810                                             &rest lmf-options)
 811                                            &body body)
 812   `(progn
 813      ,method-args ,next-methods
 814      (bind-simple-lexical-method-functions (,method-args ,next-methods
 815                                                          ,lmf-options)
 816          (bind-args (,lambda-list ,method-args)
 817            ,@body))))
 818
 819 (defmacro fast-lexical-method-functions ((lambda-list
 820                                           next-method-call
 821                                           args
 822                                           rest-arg
 823                                           &rest lmf-options)
 824                                          &body body)
 825   `(bind-fast-lexical-method-functions (,args ,rest-arg ,next-method-call ,lmf-options)
 826      (bind-args (,(nthcdr (length args) lambda-list) ,rest-arg)
 827        ,@body)))
 828
 829 (defmacro bind-simple-lexical-method-functions
 830     ((method-args next-methods (&key call-next-method-p next-method-p-p setq-p
 831                                      closurep applyp method-name-declaration))
 832      &body body
 833      &environment env)
 834   (if (not (or call-next-method-p setq-p closurep next-method-p-p applyp))
 835       `(locally
 836            ,@body)
 837       `(let ((.next-method. (car ,next-methods))
 838              (,next-methods (cdr ,next-methods)))
 839          (declare (ignorable .next-method. ,next-methods))
 840          (flet (,@(and call-next-method-p
 841                        `((call-next-method
 842                           (&rest cnm-args)
 843                           ,@(if (safe-code-p env)
 844                                 `((%check-cnm-args cnm-args
 845                                                    ,method-args
 846                                                    ',method-name-declaration))
 847                                 nil)
 848                           (if .next-method.
 849                               (funcall (if (std-instance-p .next-method.)
 850                                            (method-function .next-method.)
 851                                            .next-method.) ; for early methods
 852                                        (or cnm-args ,method-args)
 853                                        ,next-methods)
 854                               (apply #'call-no-next-method
 855                                      ',method-name-declaration
 856                                      (or cnm-args ,method-args))))))
 857                 ,@(and next-method-p-p
 858                        '((next-method-p ()
 859                           (not (null .next-method.))))))
 860            ,@body))))
 861
 862 (defun call-no-next-method (method-name-declaration &rest args)
 863   (destructuring-bind (name) method-name-declaration
 864     (destructuring-bind (name &rest qualifiers-and-specializers) name
 865       ;; KLUDGE: inefficient traversal, but hey.  This should only
 866       ;; happen on the slow error path anyway.
 867       (let* ((qualifiers (butlast qualifiers-and-specializers))
 868              (specializers (car (last qualifiers-and-specializers)))
 869              (method (find-method (gdefinition name) qualifiers specializers)))
 870         (apply #'no-next-method
 871                (method-generic-function method)
 872                method
 873                args)))))
 874
 875 (defstruct (method-call (:copier nil))
 876   (function #'identity :type function)
 877   call-method-args)
 878
 879 #-sb-fluid (declaim (sb-ext:freeze-type method-call))
 880
 881 (defmacro invoke-method-call1 (function args cm-args)
 882   `(let ((.function. ,function)
 883          (.args. ,args)
 884          (.cm-args. ,cm-args))
 885      (if (and .cm-args. (null (cdr .cm-args.)))
 886          (funcall .function. .args. (car .cm-args.))
 887          (apply .function. .args. .cm-args.))))
 888
 889 (defmacro invoke-method-call (method-call restp &rest required-args+rest-arg)
 890   `(invoke-method-call1 (method-call-function ,method-call)
 891                         ,(if restp
 892                              `(list* ,@required-args+rest-arg)
 893                              `(list ,@required-args+rest-arg))
 894                         (method-call-call-method-args ,method-call)))
 895
 896 (defstruct (fast-method-call (:copier nil))
 897   (function #'identity :type function)
 898   pv-cell
 899   next-method-call
 900   arg-info)
 901
 902 #-sb-fluid (declaim (sb-ext:freeze-type fast-method-call))
 903
 904 (defmacro fmc-funcall (fn pv-cell next-method-call &rest args)
 905   `(funcall ,fn ,pv-cell ,next-method-call ,@args))
 906
 907 (defmacro invoke-fast-method-call (method-call &rest required-args+rest-arg)
 908   `(fmc-funcall (fast-method-call-function ,method-call)
 909                 (fast-method-call-pv-cell ,method-call)
 910                 (fast-method-call-next-method-call ,method-call)
 911                 ,@required-args+rest-arg))
 912
 913 (defstruct (fast-instance-boundp (:copier nil))
 914   (index 0 :type fixnum))
 915
 916 #-sb-fluid (declaim (sb-ext:freeze-type fast-instance-boundp))
 917
 918 (eval-when (:compile-toplevel :load-toplevel :execute)
 919   (defvar *allow-emf-call-tracing-p* nil)
 920   (defvar *enable-emf-call-tracing-p* #-sb-show nil #+sb-show t))
 921 \f
 922 ;;;; effective method functions
 923
 924 (defvar *emf-call-trace-size* 200)
 925 (defvar *emf-call-trace* nil)
 926 (defvar *emf-call-trace-index* 0)
 927
 928 ;;; This function was in the CMU CL version of PCL (ca Debian 2.4.8)
 929 ;;; without explanation. It appears to be intended for debugging, so
 930 ;;; it might be useful someday, so I haven't deleted it.
 931 ;;; But it isn't documented and isn't used for anything now, so
 932 ;;; I've conditionalized it out of the base system. -- WHN 19991213
 933 #+sb-show
 934 (defun show-emf-call-trace ()
 935   (when *emf-call-trace*
 936     (let ((j *emf-call-trace-index*)
 937           (*enable-emf-call-tracing-p* nil))
 938       (format t "~&(The oldest entries are printed first)~%")
 939       (dotimes-fixnum (i *emf-call-trace-size*)
 940         (let ((ct (aref *emf-call-trace* j)))
 941           (when ct (print ct)))
 942         (incf j)
 943         (when (= j *emf-call-trace-size*)
 944           (setq j 0))))))
 945
 946 (defun trace-emf-call-internal (emf format args)
 947   (unless *emf-call-trace*
 948     (setq *emf-call-trace* (make-array *emf-call-trace-size*)))
 949   (setf (aref *emf-call-trace* *emf-call-trace-index*)
 950         (list* emf format args))
 951   (incf *emf-call-trace-index*)
 952   (when (= *emf-call-trace-index* *emf-call-trace-size*)
 953     (setq *emf-call-trace-index* 0)))
 954
 955 (defmacro trace-emf-call (emf format args)
 956   (when *allow-emf-call-tracing-p*
 957     `(when *enable-emf-call-tracing-p*
 958        (trace-emf-call-internal ,emf ,format ,args))))
 959
 960 (defmacro invoke-effective-method-function-fast
 961     (emf restp &rest required-args+rest-arg)
 962   `(progn
 963      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 964      (invoke-fast-method-call ,emf ,@required-args+rest-arg)))
 965
 966 (defmacro invoke-effective-method-function (emf restp
 967                                                 &rest required-args+rest-arg)
 968   (unless (constantp restp)
 969     (error "The RESTP argument is not constant."))
 970   ;; FIXME: The RESTP handling here is confusing and maybe slightly
 971   ;; broken if RESTP evaluates to a non-self-evaluating form. E.g. if
 972   ;;   (INVOKE-EFFECTIVE-METHOD-FUNCTION EMF '(ERROR "gotcha") ...)
 973   ;; then TRACE-EMF-CALL-CALL-INTERNAL might die on a gotcha error.
 974   (setq restp (constant-form-value restp))
 975   `(progn
 976      (trace-emf-call ,emf ,restp (list ,@required-args+rest-arg))
 977      (cond ((typep ,emf 'fast-method-call)
 978             (invoke-fast-method-call ,emf ,@required-args+rest-arg))
 979            ;; "What," you may wonder, "do these next two clauses do?"
 980            ;; In that case, you are not a PCL implementor, for they
 981            ;; considered this to be self-documenting.:-| Or CSR, for
 982            ;; that matter, since he can also figure it out by looking
 983            ;; at it without breaking stride. For the rest of us,
 984            ;; though: From what the code is doing with .SLOTS. and
 985            ;; whatnot, evidently it's implementing SLOT-VALUEish and
 986            ;; GET-SLOT-VALUEish things. Then we can reason backwards
 987            ;; and conclude that setting EMF to a FIXNUM is an
 988            ;; optimized way to represent these slot access operations.
 989            ,@(when (and (null restp) (= 1 (length required-args+rest-arg)))
 990                `(((typep ,emf 'fixnum)
 991                   (let* ((.slots. (get-slots-or-nil
 992                                    ,(car required-args+rest-arg)))
 993                          (value (when .slots. (clos-slots-ref .slots. ,emf))))
 994                     (if (eq value +slot-unbound+)
 995                         (slot-unbound-internal ,(car required-args+rest-arg)
 996                                                ,emf)
 997                         value)))))
 998            ,@(when (and (null restp) (= 2 (length required-args+rest-arg)))
 999                `(((typep ,emf 'fixnum)
1000                   (let ((.new-value. ,(car required-args+rest-arg))
1001                         (.slots. (get-slots-or-nil
1002                                   ,(cadr required-args+rest-arg))))
1003                     (when .slots.
1004                       (setf (clos-slots-ref .slots. ,emf) .new-value.))))))
1005            ;; (In cmucl-2.4.8 there was a commented-out third ,@(WHEN
1006            ;; ...) clause here to handle SLOT-BOUNDish stuff. Since
1007            ;; there was no explanation and presumably the code is 10+
1008            ;; years stale, I simply deleted it. -- WHN)
1009            (t
1010             (etypecase ,emf
1011               (method-call
1012                (invoke-method-call ,emf ,restp ,@required-args+rest-arg))
1013               (function
1014                ,(if restp
1015                     `(apply (the function ,emf) ,@required-args+rest-arg)
1016                     `(funcall (the function ,emf)
1017                               ,@required-args+rest-arg))))))))
1018
1019 (defun invoke-emf (emf args)
1020   (trace-emf-call emf t args)
1021   (etypecase emf
1022     (fast-method-call
1023      (let* ((arg-info (fast-method-call-arg-info emf))
1024             (restp (cdr arg-info))
1025             (nreq (car arg-info)))
1026        (if restp
1027            (let* ((rest-args (nthcdr nreq args))
1028                   (req-args (ldiff args rest-args)))
1029              (apply (fast-method-call-function emf)
1030                     (fast-method-call-pv-cell emf)
1031                     (fast-method-call-next-method-call emf)
1032                     (nconc req-args (list rest-args))))
1033            (cond ((null args)
1034                   (if (eql nreq 0)
1035                       (invoke-fast-method-call emf)
1036                       (error 'simple-program-error
1037                              :format-control "invalid number of arguments: 0"
1038                              :format-arguments nil)))
1039                  ((null (cdr args))
1040                   (if (eql nreq 1)
1041                       (invoke-fast-method-call emf (car args))
1042                       (error 'simple-program-error
1043                              :format-control "invalid number of arguments: 1"
1044                              :format-arguments nil)))
1045                  ((null (cddr args))
1046                   (if (eql nreq 2)
1047                       (invoke-fast-method-call emf (car args) (cadr args))
1048                       (error 'simple-program-error
1049                              :format-control "invalid number of arguments: 2"
1050                              :format-arguments nil)))
1051                  (t
1052                   (apply (fast-method-call-function emf)
1053                          (fast-method-call-pv-cell emf)
1054                          (fast-method-call-next-method-call emf)
1055                          args))))))
1056     (method-call
1057      (apply (method-call-function emf)
1058             args
1059             (method-call-call-method-args emf)))
1060     (fixnum
1061      (cond ((null args)
1062             (error 'simple-program-error
1063                    :format-control "invalid number of arguments: 0"
1064                    :format-arguments nil))
1065            ((null (cdr args))
1066             (let* ((slots (get-slots (car args)))
1067                    (value (clos-slots-ref slots emf)))
1068               (if (eq value +slot-unbound+)
1069                   (slot-unbound-internal (car args) emf)
1070                   value)))
1071            ((null (cddr args))
1072             (setf (clos-slots-ref (get-slots (cadr args)) emf)
1073                   (car args)))
1074            (t (error 'simple-program-error
1075                      :format-control "invalid number of arguments"
1076                      :format-arguments nil))))
1077     (fast-instance-boundp
1078      (if (or (null args) (cdr args))
1079          (error 'simple-program-error
1080                 :format-control "invalid number of arguments"
1081                 :format-arguments nil)
1082          (let ((slots (get-slots (car args))))
1083            (not (eq (clos-slots-ref slots (fast-instance-boundp-index emf))
1084                     +slot-unbound+)))))
1085     (function
1086      (apply emf args))))
1087 \f
1088
1089 (defmacro fast-narrowed-emf (emf)
1090   ;; INVOKE-EFFECTIVE-METHOD-FUNCTION has code in it to dispatch on
1091   ;; the possibility that EMF might be of type FIXNUM (as an optimized
1092   ;; representation of a slot accessor). But as far as I (WHN
1093   ;; 2002-06-11) can tell, it's impossible for such a representation
1094   ;; to end up as .NEXT-METHOD-CALL. By reassuring INVOKE-E-M-F that
1095   ;; when called from this context it needn't worry about the FIXNUM
1096   ;; case, we can keep those cases from being compiled, which is good
1097   ;; both because it saves bytes and because it avoids annoying type
1098   ;; mismatch compiler warnings.
1099   ;;
1100   ;; KLUDGE: In sbcl-0.7.4.29, the compiler's type system isn't smart
1101   ;; enough about NOT and intersection types to benefit from a (NOT
1102   ;; FIXNUM) declaration here. -- WHN 2002-06-12 (FIXME: maybe it is
1103   ;; now... -- CSR, 2003-06-07)
1104   ;;
1105   ;; FIXME: Might the FUNCTION type be omittable here, leaving only
1106   ;; METHOD-CALLs? Failing that, could this be documented somehow?
1107   ;; (It'd be nice if the types involved could be understood without
1108   ;; solving the halting problem.)
1109   `(the (or function method-call fast-method-call)
1110      ,emf))
1111
1112 (defmacro fast-call-next-method-body ((args next-method-call rest-arg)
1113                                       method-name-declaration
1114                                       cnm-args)
1115   `(if ,next-method-call
1116        ,(let ((call `(invoke-effective-method-function
1117                       (fast-narrowed-emf ,next-method-call)
1118                       ,(not (null rest-arg))
1119                       ,@args
1120                       ,@(when rest-arg `(,rest-arg)))))
1121              `(if ,cnm-args
1122                   (bind-args ((,@args
1123                                ,@(when rest-arg
1124                                        `(&rest ,rest-arg)))
1125                               ,cnm-args)
1126                     ,call)
1127                   ,call))
1128        (call-no-next-method ',method-name-declaration
1129                             ,@args
1130                             ,@(when rest-arg
1131                                     `(,rest-arg)))))
1132
1133 (defmacro bind-fast-lexical-method-functions
1134     ((args rest-arg next-method-call (&key
1135                                       call-next-method-p
1136                                       setq-p
1137                                       method-name-declaration
1138                                       next-method-p-p
1139                                       closurep
1140                                       applyp))
1141      &body body
1142      &environment env)
1143   (let* ((all-params (append args (when rest-arg (list rest-arg))))
1144          (rebindings (when (or setq-p call-next-method-p)
1145                        (mapcar (lambda (x) (list x x)) all-params))))
1146     (if (not (or call-next-method-p setq-p closurep next-method-p-p applyp))
1147         `(locally
1148              ,@body)
1149         `(flet (,@(when call-next-method-p
1150                         `((call-next-method (&rest cnm-args)
1151                            (declare (muffle-conditions code-deletion-note))
1152                            ,@(if (safe-code-p env)
1153                                  `((%check-cnm-args cnm-args (list ,@args)
1154                                                     ',method-name-declaration))
1155                                  nil)
1156                            (fast-call-next-method-body (,args
1157                                                         ,next-method-call
1158                                                         ,rest-arg)
1159                                                         ,method-name-declaration
1160                                                        cnm-args))))
1161                 ,@(when next-method-p-p
1162                         `((next-method-p
1163                            ()
1164                            (not (null ,next-method-call))))))
1165            (let ,rebindings
1166              ,@(when rebindings `((declare (ignorable ,@all-params))))
1167              ,@body)))))
1168
1169 ;;; CMUCL comment (Gerd Moellmann):
1170 ;;;
1171 ;;; The standard says it's an error if CALL-NEXT-METHOD is called with
1172 ;;; arguments, and the set of methods applicable to those arguments is
1173 ;;; different from the set of methods applicable to the original
1174 ;;; method arguments.  (According to Barry Margolin, this rule was
1175 ;;; probably added to ensure that before and around methods are always
1176 ;;; run before primary methods.)
1177 ;;;
1178 ;;; This could be optimized for the case that the generic function
1179 ;;; doesn't have hairy methods, does have standard method combination,
1180 ;;; is a standard generic function, there are no methods defined on it
1181 ;;; for COMPUTE-APPLICABLE-METHODS and probably a lot more of such
1182 ;;; preconditions.  That looks hairy and is probably not worth it,
1183 ;;; because this check will never be fast.
1184 (defun %check-cnm-args (cnm-args orig-args method-name-declaration)
1185   (when cnm-args
1186     (let* ((gf (fdefinition (caar method-name-declaration)))
1187            (omethods (compute-applicable-methods gf orig-args))
1188            (nmethods (compute-applicable-methods gf cnm-args)))
1189       (unless (equal omethods nmethods)
1190         (error "~@<The set of methods ~S applicable to argument~P ~
1191                 ~{~S~^, ~} to call-next-method is different from ~
1192                 the set of methods ~S applicable to the original ~
1193                 method argument~P ~{~S~^, ~}.~@:>"
1194                nmethods (length cnm-args) cnm-args omethods
1195                (length orig-args) orig-args)))))
1196
1197 (defmacro bind-args ((lambda-list args) &body body)
1198   (let ((args-tail '.args-tail.)
1199         (key '.key.)
1200         (state 'required))
1201     (flet ((process-var (var)
1202              (if (memq var lambda-list-keywords)
1203                  (progn
1204                    (case var
1205                      (&optional       (setq state 'optional))
1206                      (&key            (setq state 'key))
1207                      (&allow-other-keys)
1208                      (&rest           (setq state 'rest))
1209                      (&aux            (setq state 'aux))
1210                      (otherwise
1211                       (error
1212                        "encountered the non-standard lambda list keyword ~S"
1213                        var)))
1214                    nil)
1215                  (case state
1216                    (required `((,var (pop ,args-tail))))
1217                    (optional (cond ((not (consp var))
1218                                     `((,var (when ,args-tail
1219                                               (pop ,args-tail)))))
1220                                    ((null (cddr var))
1221                                     `((,(car var) (if ,args-tail
1222                                                       (pop ,args-tail)
1223                                                       ,(cadr var)))))
1224                                    (t
1225                                     `((,(caddr var) ,args-tail)
1226                                       (,(car var) (if ,args-tail
1227                                                       (pop ,args-tail)
1228                                                       ,(cadr var)))))))
1229                    (rest `((,var ,args-tail)))
1230                    (key (cond ((not (consp var))
1231                                `((,var (car
1232                                         (get-key-arg-tail ,(keywordicate var)
1233                                                           ,args-tail)))))
1234                               ((null (cddr var))
1235                                (multiple-value-bind (keyword variable)
1236                                    (if (consp (car var))
1237                                        (values (caar var)
1238                                                (cadar var))
1239                                        (values (keywordicate (car var))
1240                                                (car var)))
1241                                  `((,key (get-key-arg-tail ',keyword
1242                                                            ,args-tail))
1243                                    (,variable (if ,key
1244                                                   (car ,key)
1245                                                   ,(cadr var))))))
1246                               (t
1247                                (multiple-value-bind (keyword variable)
1248                                    (if (consp (car var))
1249                                        (values (caar var)
1250                                                (cadar var))
1251                                        (values (keywordicate (car var))
1252                                                (car var)))
1253                                  `((,key (get-key-arg-tail ',keyword
1254                                                            ,args-tail))
1255                                    (,(caddr var) ,key)
1256                                    (,variable (if ,key
1257                                                   (car ,key)
1258                                                   ,(cadr var))))))))
1259                    (aux `(,var))))))
1260       (let ((bindings (mapcan #'process-var lambda-list)))
1261         `(let* ((,args-tail ,args)
1262                 ,@bindings
1263                 (.dummy0.
1264                  ,@(when (eq state 'optional)
1265                      `((unless (null ,args-tail)
1266                          (error 'simple-program-error
1267                                 :format-control "surplus arguments: ~S"
1268                                 :format-arguments (list ,args-tail)))))))
1269            (declare (ignorable ,args-tail .dummy0.))
1270            ,@body)))))
1271
1272 (defun get-key-arg-tail (keyword list)
1273   (loop for (key . tail) on list by #'cddr
1274         when (null tail) do
1275           ;; FIXME: Do we want to export this symbol? Or maybe use an
1276           ;; (ERROR 'SIMPLE-PROGRAM-ERROR) form?
1277           (sb-c::%odd-key-args-error)
1278         when (eq key keyword)
1279           return tail))
1280
1281 (defun walk-method-lambda (method-lambda required-parameters env slots calls)
1282   (let ((call-next-method-p nil)   ; flag indicating that CALL-NEXT-METHOD
1283                                    ; should be in the method definition
1284         (closurep nil)             ; flag indicating that #'CALL-NEXT-METHOD
1285                                    ; was seen in the body of a method
1286         (next-method-p-p nil)      ; flag indicating that NEXT-METHOD-P
1287                                    ; should be in the method definition
1288         (setq-p nil))
1289     (flet ((walk-function (form context env)
1290              (cond ((not (eq context :eval)) form)
1291                    ;; FIXME: Jumping to a conclusion from the way it's used
1292                    ;; above, perhaps CONTEXT should be called SITUATION
1293                    ;; (after the term used in the ANSI specification of
1294                    ;; EVAL-WHEN) and given modern ANSI keyword values
1295                    ;; like :LOAD-TOPLEVEL.
1296                    ((not (listp form)) form)
1297                    ((eq (car form) 'call-next-method)
1298                     (setq call-next-method-p t)
1299                     form)
1300                    ((eq (car form) 'next-method-p)
1301                     (setq next-method-p-p t)
1302                     form)
1303                    ((memq (car form) '(setq multiple-value-setq))
1304                     ;; FIXME: this is possibly a little strong as
1305                     ;; conditions go.  Ideally we would want to detect
1306                     ;; which, if any, of the method parameters are
1307                     ;; being set, and communicate that information to
1308                     ;; e.g. SPLIT-DECLARATIONS.  However, the brute
1309                     ;; force method doesn't really cost much; a little
1310                     ;; loss of discrimination over IGNORED variables
1311                     ;; should be all.  -- CSR, 2004-07-01
1312                     (setq setq-p t)
1313                     form)
1314                    ((and (eq (car form) 'function)
1315                          (cond ((eq (cadr form) 'call-next-method)
1316                                 (setq call-next-method-p t)
1317                                 (setq closurep t)
1318                                 form)
1319                                ((eq (cadr form) 'next-method-p)
1320                                 (setq next-method-p-p t)
1321                                 (setq closurep t)
1322                                 form)
1323                                (t nil))))
1324                    ((and (memq (car form)
1325                                '(slot-value set-slot-value slot-boundp))
1326                          (constantp (caddr form)))
1327                      (let ((parameter (can-optimize-access form
1328                                                            required-parameters
1329                                                            env)))
1330                       (let ((fun (ecase (car form)
1331                                    (slot-value #'optimize-slot-value)
1332                                    (set-slot-value #'optimize-set-slot-value)
1333                                    (slot-boundp #'optimize-slot-boundp))))
1334                         (funcall fun slots parameter form))))
1335                    ((and (eq (car form) 'apply)
1336                          (consp (cadr form))
1337                          (eq (car (cadr form)) 'function)
1338                          (generic-function-name-p (cadr (cadr form))))
1339                     (optimize-generic-function-call
1340                      form required-parameters env slots calls))
1341                    ((generic-function-name-p (car form))
1342                     (optimize-generic-function-call
1343                      form required-parameters env slots calls))
1344                    (t form))))
1345
1346       (let ((walked-lambda (walk-form method-lambda env #'walk-function)))
1347         (values walked-lambda
1348                 call-next-method-p
1349                 closurep
1350                 next-method-p-p
1351                 setq-p)))))
1352
1353 (defun generic-function-name-p (name)
1354   (and (legal-fun-name-p name)
1355        (fboundp name)
1356        (if (eq *boot-state* 'complete)
1357            (standard-generic-function-p (gdefinition name))
1358            (funcallable-instance-p (gdefinition name)))))
1359 \f
1360 (defvar *method-function-plist* (make-hash-table :test 'eq))
1361
1362 (defun method-function-plist (method-function)
1363   (gethash method-function *method-function-plist*))
1364
1365 (defun (setf method-function-plist) (val method-function)
1366   (setf (gethash method-function *method-function-plist*) val))
1367
1368 (defun method-function-get (method-function key &optional default)
1369   (getf (method-function-plist method-function) key default))
1370
1371 (defun (setf method-function-get)
1372     (val method-function key)
1373   (setf (getf (method-function-plist method-function) key) val))
1374
1375 (defun method-function-pv-table (method-function)
1376   (method-function-get method-function :pv-table))
1377
1378 (defun method-function-method (method-function)
1379   (method-function-get method-function :method))
1380
1381 (defun method-function-needs-next-methods-p (method-function)
1382   (method-function-get method-function :needs-next-methods-p t))
1383 \f
1384 (defmacro method-function-closure-generator (method-function)
1385   `(method-function-get ,method-function 'closure-generator))
1386
1387 (defun load-defmethod
1388     (class name quals specls ll initargs source-location)
1389   (setq initargs (copy-tree initargs))
1390   (let ((method-spec (or (getf initargs :method-spec)
1391                          (make-method-spec name quals specls))))
1392     (setf (getf initargs :method-spec) method-spec)
1393     (load-defmethod-internal class name quals specls
1394                              ll initargs source-location)))
1395
1396 (defun load-defmethod-internal
1397     (method-class gf-spec qualifiers specializers lambda-list
1398                   initargs source-location)
1399   (when (and (eq *boot-state* 'complete)
1400              (fboundp gf-spec))
1401     (let* ((gf (fdefinition gf-spec))
1402            (method (and (generic-function-p gf)
1403                         (generic-function-methods gf)
1404                         (find-method gf
1405                                      qualifiers
1406                                      (parse-specializers specializers)
1407                                      nil))))
1408       (when method
1409         (style-warn "redefining ~S~{ ~S~} ~S in DEFMETHOD"
1410                     gf-spec qualifiers specializers))))
1411   (let ((method (apply #'add-named-method
1412                        gf-spec qualifiers specializers lambda-list
1413                        :definition-source source-location
1414                        initargs)))
1415     (unless (or (eq method-class 'standard-method)
1416                 (eq (find-class method-class nil) (class-of method)))
1417       ;; FIXME: should be STYLE-WARNING?
1418       (format *error-output*
1419               "~&At the time the method with qualifiers ~:S and~%~
1420                specializers ~:S on the generic function ~S~%~
1421                was compiled, the method-class for that generic function was~%~
1422                ~S. But, the method class is now ~S, this~%~
1423                may mean that this method was compiled improperly.~%"
1424               qualifiers specializers gf-spec
1425               method-class (class-name (class-of method))))
1426     method))
1427
1428 (defun make-method-spec (gf-spec qualifiers unparsed-specializers)
1429   `(slow-method ,gf-spec ,@qualifiers ,unparsed-specializers))
1430
1431 (defun initialize-method-function (initargs &optional return-function-p method)
1432   (let* ((mf (getf initargs :function))
1433          (method-spec (getf initargs :method-spec))
1434          (plist (getf initargs :plist))
1435          (pv-table-symbol (getf plist :pv-table-symbol))
1436          (pv-table nil)
1437          (mff (getf initargs :fast-function)))
1438     (flet ((set-mf-property (p v)
1439              (when mf
1440                (setf (method-function-get mf p) v))
1441              (when mff
1442                (setf (method-function-get mff p) v))))
1443       (when method-spec
1444         (when mf
1445           (setq mf (set-fun-name mf method-spec)))
1446         (when mff
1447           (let ((name `(fast-method ,@(cdr method-spec))))
1448             (set-fun-name mff name)
1449             (unless mf
1450               (set-mf-property :name name)))))
1451       (when plist
1452         (let ((snl (getf plist :slot-name-lists))
1453               (cl (getf plist :call-list)))
1454           (when (or snl cl)
1455             (setq pv-table (intern-pv-table :slot-name-lists snl
1456                                             :call-list cl))
1457             (when pv-table (set pv-table-symbol pv-table))
1458             (set-mf-property :pv-table pv-table)))
1459         (loop (when (null plist) (return nil))
1460               (set-mf-property (pop plist) (pop plist)))
1461         (when method
1462           (set-mf-property :method method))
1463         (when return-function-p
1464           (or mf (method-function-from-fast-function mff)))))))
1465 \f
1466 (defun analyze-lambda-list (lambda-list)
1467   (flet (;; FIXME: Is this redundant with SB-C::MAKE-KEYWORD-FOR-ARG?
1468          (parse-key-arg (arg)
1469            (if (listp arg)
1470                (if (listp (car arg))
1471                    (caar arg)
1472                    (keywordicate (car arg)))
1473                (keywordicate arg))))
1474     (let ((nrequired 0)
1475           (noptional 0)
1476           (keysp nil)
1477           (restp nil)
1478           (nrest 0)
1479           (allow-other-keys-p nil)
1480           (keywords ())
1481           (keyword-parameters ())
1482           (state 'required))
1483       (dolist (x lambda-list)
1484         (if (memq x lambda-list-keywords)
1485             (case x
1486               (&optional         (setq state 'optional))
1487               (&key              (setq keysp t
1488                                        state 'key))
1489               (&allow-other-keys (setq allow-other-keys-p t))
1490               (&rest             (setq restp t
1491                                        state 'rest))
1492               (&aux           (return t))
1493               (otherwise
1494                 (error "encountered the non-standard lambda list keyword ~S"
1495                        x)))
1496             (ecase state
1497               (required  (incf nrequired))
1498               (optional  (incf noptional))
1499               (key       (push (parse-key-arg x) keywords)
1500                          (push x keyword-parameters))
1501               (rest      (incf nrest)))))
1502       (when (and restp (zerop nrest))
1503         (error "Error in lambda-list:~%~
1504                 After &REST, a DEFGENERIC lambda-list ~
1505                 must be followed by at least one variable."))
1506       (values nrequired noptional keysp restp allow-other-keys-p
1507               (reverse keywords)
1508               (reverse keyword-parameters)))))
1509
1510 (defun keyword-spec-name (x)
1511   (let ((key (if (atom x) x (car x))))
1512     (if (atom key)
1513         (keywordicate key)
1514         (car key))))
1515
1516 (defun ftype-declaration-from-lambda-list (lambda-list name)
1517   (multiple-value-bind (nrequired noptional keysp restp allow-other-keys-p
1518                                   keywords keyword-parameters)
1519       (analyze-lambda-list lambda-list)
1520     (declare (ignore keyword-parameters))
1521     (let* ((old (info :function :type name)) ;FIXME:FDOCUMENTATION instead?
1522            (old-ftype (if (fun-type-p old) old nil))
1523            (old-restp (and old-ftype (fun-type-rest old-ftype)))
1524            (old-keys (and old-ftype
1525                           (mapcar #'key-info-name
1526                                   (fun-type-keywords
1527                                    old-ftype))))
1528            (old-keysp (and old-ftype (fun-type-keyp old-ftype)))
1529            (old-allowp (and old-ftype
1530                             (fun-type-allowp old-ftype)))
1531            (keywords (union old-keys (mapcar #'keyword-spec-name keywords))))
1532       `(function ,(append (make-list nrequired :initial-element t)
1533                           (when (plusp noptional)
1534                             (append '(&optional)
1535                                     (make-list noptional :initial-element t)))
1536                           (when (or restp old-restp)
1537                             '(&rest t))
1538                           (when (or keysp old-keysp)
1539                             (append '(&key)
1540                                     (mapcar (lambda (key)
1541                                               `(,key t))
1542                                             keywords)
1543                                     (when (or allow-other-keys-p old-allowp)
1544                                       '(&allow-other-keys)))))
1545                  *))))
1546
1547 (defun defgeneric-declaration (spec lambda-list)
1548   `(ftype ,(ftype-declaration-from-lambda-list lambda-list spec) ,spec))
1549 \f
1550 ;;;; early generic function support
1551
1552 (defvar *!early-generic-functions* ())
1553
1554 (defun ensure-generic-function (fun-name
1555                                 &rest all-keys
1556                                 &key environment source-location
1557                                 &allow-other-keys)
1558   (declare (ignore environment))
1559   (let ((existing (and (fboundp fun-name)
1560                        (gdefinition fun-name))))
1561     (if (and existing
1562              (eq *boot-state* 'complete)
1563              (null (generic-function-p existing)))
1564         (generic-clobbers-function fun-name)
1565         (apply #'ensure-generic-function-using-class
1566                existing fun-name all-keys))))
1567
1568 (defun generic-clobbers-function (fun-name)
1569   (error 'simple-program-error
1570          :format-control "~S already names an ordinary function or a macro."
1571          :format-arguments (list fun-name)))
1572
1573 (defvar *sgf-wrapper*
1574   (boot-make-wrapper (early-class-size 'standard-generic-function)
1575                      'standard-generic-function))
1576
1577 (defvar *sgf-slots-init*
1578   (mapcar (lambda (canonical-slot)
1579             (if (memq (getf canonical-slot :name) '(arg-info source))
1580                 +slot-unbound+
1581                 (let ((initfunction (getf canonical-slot :initfunction)))
1582                   (if initfunction
1583                       (funcall initfunction)
1584                       +slot-unbound+))))
1585           (early-collect-inheritance 'standard-generic-function)))
1586
1587 (defvar *sgf-method-class-index*
1588   (!bootstrap-slot-index 'standard-generic-function 'method-class))
1589
1590 (defun early-gf-p (x)
1591   (and (fsc-instance-p x)
1592        (eq (clos-slots-ref (get-slots x) *sgf-method-class-index*)
1593            +slot-unbound+)))
1594
1595 (defvar *sgf-methods-index*
1596   (!bootstrap-slot-index 'standard-generic-function 'methods))
1597
1598 (defmacro early-gf-methods (gf)
1599   `(clos-slots-ref (get-slots ,gf) *sgf-methods-index*))
1600
1601 (defun safe-generic-function-methods (generic-function)
1602   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1603       (clos-slots-ref (get-slots generic-function) *sgf-methods-index*)
1604       (generic-function-methods generic-function)))
1605
1606 (defvar *sgf-arg-info-index*
1607   (!bootstrap-slot-index 'standard-generic-function 'arg-info))
1608
1609 (defmacro early-gf-arg-info (gf)
1610   `(clos-slots-ref (get-slots ,gf) *sgf-arg-info-index*))
1611
1612 (defvar *sgf-dfun-state-index*
1613   (!bootstrap-slot-index 'standard-generic-function 'dfun-state))
1614
1615 (defstruct (arg-info
1616             (:conc-name nil)
1617             (:constructor make-arg-info ())
1618             (:copier nil))
1619   (arg-info-lambda-list :no-lambda-list)
1620   arg-info-precedence
1621   arg-info-metatypes
1622   arg-info-number-optional
1623   arg-info-key/rest-p
1624   arg-info-keys   ;nil        no &KEY or &REST allowed
1625                   ;(k1 k2 ..) Each method must accept these &KEY arguments.
1626                   ;T          must have &KEY or &REST
1627
1628   gf-info-simple-accessor-type ; nil, reader, writer, boundp
1629   (gf-precompute-dfun-and-emf-p nil) ; set by set-arg-info
1630
1631   gf-info-static-c-a-m-emf
1632   (gf-info-c-a-m-emf-std-p t)
1633   gf-info-fast-mf-p)
1634
1635 #-sb-fluid (declaim (sb-ext:freeze-type arg-info))
1636
1637 (defun arg-info-valid-p (arg-info)
1638   (not (null (arg-info-number-optional arg-info))))
1639
1640 (defun arg-info-applyp (arg-info)
1641   (or (plusp (arg-info-number-optional arg-info))
1642       (arg-info-key/rest-p arg-info)))
1643
1644 (defun arg-info-number-required (arg-info)
1645   (length (arg-info-metatypes arg-info)))
1646
1647 (defun arg-info-nkeys (arg-info)
1648   (count-if (lambda (x) (neq x t)) (arg-info-metatypes arg-info)))
1649
1650 (defun create-gf-lambda-list (lambda-list)
1651   ;;; Create a gf lambda list from a method lambda list
1652   (loop for x in lambda-list
1653         collect (if (consp x) (list (car x)) x)
1654         if (eq x '&key) do (loop-finish)))
1655
1656 (defun set-arg-info (gf &key new-method (lambda-list nil lambda-list-p)
1657                         argument-precedence-order)
1658   (let* ((arg-info (if (eq *boot-state* 'complete)
1659                        (gf-arg-info gf)
1660                        (early-gf-arg-info gf)))
1661          (methods (if (eq *boot-state* 'complete)
1662                       (generic-function-methods gf)
1663                       (early-gf-methods gf)))
1664          (was-valid-p (integerp (arg-info-number-optional arg-info)))
1665          (first-p (and new-method (null (cdr methods)))))
1666     (when (and (not lambda-list-p) methods)
1667       (setq lambda-list (gf-lambda-list gf)))
1668     (when (or lambda-list-p
1669               (and first-p
1670                    (eq (arg-info-lambda-list arg-info) :no-lambda-list)))
1671       (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1672           (analyze-lambda-list lambda-list)
1673         (when (and methods (not first-p))
1674           (let ((gf-nreq (arg-info-number-required arg-info))
1675                 (gf-nopt (arg-info-number-optional arg-info))
1676                 (gf-key/rest-p (arg-info-key/rest-p arg-info)))
1677             (unless (and (= nreq gf-nreq)
1678                          (= nopt gf-nopt)
1679                          (eq (or keysp restp) gf-key/rest-p))
1680               (error "The lambda-list ~S is incompatible with ~
1681                      existing methods of ~S."
1682                      lambda-list gf))))
1683         (setf (arg-info-lambda-list arg-info)
1684               (if lambda-list-p
1685                   lambda-list
1686                    (create-gf-lambda-list lambda-list)))
1687         (when (or lambda-list-p argument-precedence-order
1688                   (null (arg-info-precedence arg-info)))
1689           (setf (arg-info-precedence arg-info)
1690                 (compute-precedence lambda-list nreq argument-precedence-order)))
1691         (setf (arg-info-metatypes arg-info) (make-list nreq))
1692         (setf (arg-info-number-optional arg-info) nopt)
1693         (setf (arg-info-key/rest-p arg-info) (not (null (or keysp restp))))
1694         (setf (arg-info-keys arg-info)
1695               (if lambda-list-p
1696                   (if allow-other-keys-p t keywords)
1697                   (arg-info-key/rest-p arg-info)))))
1698     (when new-method
1699       (check-method-arg-info gf arg-info new-method))
1700     (set-arg-info1 gf arg-info new-method methods was-valid-p first-p)
1701     arg-info))
1702
1703 (defun check-method-arg-info (gf arg-info method)
1704   (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1705       (analyze-lambda-list (if (consp method)
1706                                (early-method-lambda-list method)
1707                                (method-lambda-list method)))
1708     (flet ((lose (string &rest args)
1709              (error 'simple-program-error
1710                     :format-control "~@<attempt to add the method~2I~_~S~I~_~
1711                                      to the generic function~2I~_~S;~I~_~
1712                                      but ~?~:>"
1713                     :format-arguments (list method gf string args)))
1714            (comparison-description (x y)
1715              (if (> x y) "more" "fewer")))
1716       (let ((gf-nreq (arg-info-number-required arg-info))
1717             (gf-nopt (arg-info-number-optional arg-info))
1718             (gf-key/rest-p (arg-info-key/rest-p arg-info))
1719             (gf-keywords (arg-info-keys arg-info)))
1720         (unless (= nreq gf-nreq)
1721           (lose
1722            "the method has ~A required arguments than the generic function."
1723            (comparison-description nreq gf-nreq)))
1724         (unless (= nopt gf-nopt)
1725           (lose
1726            "the method has ~A optional arguments than the generic function."
1727            (comparison-description nopt gf-nopt)))
1728         (unless (eq (or keysp restp) gf-key/rest-p)
1729           (lose
1730            "the method and generic function differ in whether they accept~_~
1731             &REST or &KEY arguments."))
1732         (when (consp gf-keywords)
1733           (unless (or (and restp (not keysp))
1734                       allow-other-keys-p
1735                       (every (lambda (k) (memq k keywords)) gf-keywords))
1736             (lose "the method does not accept each of the &KEY arguments~2I~_~
1737                    ~S."
1738                   gf-keywords)))))))
1739
1740 (defvar *sm-specializers-index*
1741   (!bootstrap-slot-index 'standard-method 'specializers))
1742 (defvar *sm-fast-function-index*
1743   (!bootstrap-slot-index 'standard-method 'fast-function))
1744 (defvar *sm-%function-index*
1745   (!bootstrap-slot-index 'standard-method '%function))
1746 (defvar *sm-plist-index*
1747   (!bootstrap-slot-index 'standard-method 'plist))
1748
1749 ;;; FIXME: we don't actually need this; we could test for the exact
1750 ;;; class and deal with it as appropriate.  In fact we probably don't
1751 ;;; need it anyway because we only use this for METHOD-SPECIALIZERS on
1752 ;;; the standard reader method for METHOD-SPECIALIZERS.  Probably.
1753 (dolist (s '(specializers fast-function %function plist))
1754   (aver (= (symbol-value (intern (format nil "*SM-~A-INDEX*" s)))
1755            (!bootstrap-slot-index 'standard-reader-method s)
1756            (!bootstrap-slot-index 'standard-writer-method s)
1757            (!bootstrap-slot-index 'standard-boundp-method s))))
1758
1759 (defun safe-method-specializers (method)
1760   (let ((standard-method-classes
1761          (list *the-class-standard-method*
1762                *the-class-standard-reader-method*
1763                *the-class-standard-writer-method*
1764                *the-class-standard-boundp-method*))
1765         (class (class-of method)))
1766     (if (member class standard-method-classes)
1767         (clos-slots-ref (get-slots method) *sm-specializers-index*)
1768         (method-specializers method))))
1769 (defun safe-method-fast-function (method)
1770   (let ((standard-method-classes
1771          (list *the-class-standard-method*
1772                *the-class-standard-reader-method*
1773                *the-class-standard-writer-method*
1774                *the-class-standard-boundp-method*))
1775         (class (class-of method)))
1776     (if (member class standard-method-classes)
1777         (clos-slots-ref (get-slots method) *sm-fast-function-index*)
1778         (method-fast-function method))))
1779 (defun safe-method-function (method)
1780   (let ((standard-method-classes
1781          (list *the-class-standard-method*
1782                *the-class-standard-reader-method*
1783                *the-class-standard-writer-method*
1784                *the-class-standard-boundp-method*))
1785         (class (class-of method)))
1786     (if (member class standard-method-classes)
1787         (clos-slots-ref (get-slots method) *sm-%function-index*)
1788         (method-function method))))
1789 (defun safe-method-qualifiers (method)
1790   (let ((standard-method-classes
1791          (list *the-class-standard-method*
1792                *the-class-standard-reader-method*
1793                *the-class-standard-writer-method*
1794                *the-class-standard-boundp-method*))
1795         (class (class-of method)))
1796     (if (member class standard-method-classes)
1797         (let ((plist (clos-slots-ref (get-slots method) *sm-plist-index*)))
1798           (getf plist 'qualifiers))
1799         (method-qualifiers method))))
1800
1801 (defun set-arg-info1 (gf arg-info new-method methods was-valid-p first-p)
1802   (let* ((existing-p (and methods (cdr methods) new-method))
1803          (nreq (length (arg-info-metatypes arg-info)))
1804          (metatypes (if existing-p
1805                         (arg-info-metatypes arg-info)
1806                         (make-list nreq)))
1807          (type (if existing-p
1808                    (gf-info-simple-accessor-type arg-info)
1809                    nil)))
1810     (when (arg-info-valid-p arg-info)
1811       (dolist (method (if new-method (list new-method) methods))
1812         (let* ((specializers (if (or (eq *boot-state* 'complete)
1813                                      (not (consp method)))
1814                                  (safe-method-specializers method)
1815                                  (early-method-specializers method t)))
1816                (class (if (or (eq *boot-state* 'complete) (not (consp method)))
1817                           (class-of method)
1818                           (early-method-class method)))
1819                (new-type
1820                 (when (and class
1821                            (or (not (eq *boot-state* 'complete))
1822                                (eq (generic-function-method-combination gf)
1823                                    *standard-method-combination*)))
1824                   (cond ((or (eq class *the-class-standard-reader-method*)
1825                              (eq class *the-class-global-reader-method*))
1826                          'reader)
1827                         ((or (eq class *the-class-standard-writer-method*)
1828                              (eq class *the-class-global-writer-method*))
1829                          'writer)
1830                         ((or (eq class *the-class-standard-boundp-method*)
1831                              (eq class *the-class-global-boundp-method*))
1832                          'boundp)))))
1833           (setq metatypes (mapcar #'raise-metatype metatypes specializers))
1834           (setq type (cond ((null type) new-type)
1835                            ((eq type new-type) type)
1836                            (t nil)))))
1837       (setf (arg-info-metatypes arg-info) metatypes)
1838       (setf (gf-info-simple-accessor-type arg-info) type)))
1839   (when (or (not was-valid-p) first-p)
1840     (multiple-value-bind (c-a-m-emf std-p)
1841         (if (early-gf-p gf)
1842             (values t t)
1843             (compute-applicable-methods-emf gf))
1844       (setf (gf-info-static-c-a-m-emf arg-info) c-a-m-emf)
1845       (setf (gf-info-c-a-m-emf-std-p arg-info) std-p)
1846       (unless (gf-info-c-a-m-emf-std-p arg-info)
1847         (setf (gf-info-simple-accessor-type arg-info) t))))
1848   (unless was-valid-p
1849     (let ((name (if (eq *boot-state* 'complete)
1850                     (generic-function-name gf)
1851                     (!early-gf-name gf))))
1852       (setf (gf-precompute-dfun-and-emf-p arg-info)
1853             (cond
1854               ((and (consp name)
1855                     (member (car name)
1856                             *internal-pcl-generalized-fun-name-symbols*))
1857                 nil)
1858               (t (let* ((symbol (fun-name-block-name name))
1859                         (package (symbol-package symbol)))
1860                    (and (or (eq package *pcl-package*)
1861                             (memq package (package-use-list *pcl-package*)))
1862                         ;; FIXME: this test will eventually be
1863                         ;; superseded by the *internal-pcl...* test,
1864                         ;; above.  While we are in a process of
1865                         ;; transition, however, it should probably
1866                         ;; remain.
1867                         (not (find #\Space (symbol-name symbol))))))))))
1868   (setf (gf-info-fast-mf-p arg-info)
1869         (or (not (eq *boot-state* 'complete))
1870             (let* ((method-class (generic-function-method-class gf))
1871                    (methods (compute-applicable-methods
1872                              #'make-method-lambda
1873                              (list gf (class-prototype method-class)
1874                                    '(lambda) nil))))
1875               (and methods (null (cdr methods))
1876                    (let ((specls (method-specializers (car methods))))
1877                      (and (classp (car specls))
1878                           (eq 'standard-generic-function
1879                               (class-name (car specls)))
1880                           (classp (cadr specls))
1881                           (eq 'standard-method
1882                               (class-name (cadr specls)))))))))
1883   arg-info)
1884
1885 ;;; This is the early definition of ENSURE-GENERIC-FUNCTION-USING-CLASS.
1886 ;;;
1887 ;;; The STATIC-SLOTS field of the funcallable instances used as early
1888 ;;; generic functions is used to store the early methods and early
1889 ;;; discriminator code for the early generic function. The static
1890 ;;; slots field of the fins contains a list whose:
1891 ;;;    CAR    -   a list of the early methods on this early gf
1892 ;;;    CADR   -   the early discriminator code for this method
1893 (defun ensure-generic-function-using-class (existing spec &rest keys
1894                                             &key (lambda-list nil
1895                                                               lambda-list-p)
1896                                             argument-precedence-order
1897                                             source-location
1898                                             &allow-other-keys)
1899   (declare (ignore keys))
1900   (cond ((and existing (early-gf-p existing))
1901          (when lambda-list-p
1902            (set-arg-info existing :lambda-list lambda-list))
1903          existing)
1904         ((assoc spec *!generic-function-fixups* :test #'equal)
1905          (if existing
1906              (make-early-gf spec lambda-list lambda-list-p existing
1907                             argument-precedence-order source-location)
1908              (error "The function ~S is not already defined." spec)))
1909         (existing
1910          (error "~S should be on the list ~S."
1911                 spec
1912                 '*!generic-function-fixups*))
1913         (t
1914          (pushnew spec *!early-generic-functions* :test #'equal)
1915          (make-early-gf spec lambda-list lambda-list-p nil
1916                         argument-precedence-order source-location))))
1917
1918 (defun make-early-gf (spec &optional lambda-list lambda-list-p
1919                       function argument-precedence-order source-location)
1920   (let ((fin (allocate-standard-funcallable-instance
1921               *sgf-wrapper* *sgf-slots-init*)))
1922     (set-funcallable-instance-function
1923      fin
1924      (or function
1925          (if (eq spec 'print-object)
1926              #'(lambda (instance stream)
1927                  (print-unreadable-object (instance stream :identity t)
1928                    (format stream "std-instance")))
1929              #'(lambda (&rest args)
1930                  (declare (ignore args))
1931                  (error "The function of the funcallable-instance ~S~
1932                          has not been set." fin)))))
1933     (setf (gdefinition spec) fin)
1934     (!bootstrap-set-slot 'standard-generic-function fin 'name spec)
1935     (!bootstrap-set-slot 'standard-generic-function
1936                          fin
1937                          'source
1938                          source-location)
1939     (set-fun-name fin spec)
1940     (let ((arg-info (make-arg-info)))
1941       (setf (early-gf-arg-info fin) arg-info)
1942       (when lambda-list-p
1943         (proclaim (defgeneric-declaration spec lambda-list))
1944         (if argument-precedence-order
1945             (set-arg-info fin
1946                           :lambda-list lambda-list
1947                           :argument-precedence-order argument-precedence-order)
1948             (set-arg-info fin :lambda-list lambda-list))))
1949     fin))
1950
1951 (defun safe-gf-dfun-state (generic-function)
1952   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1953       (clos-slots-ref (get-slots generic-function) *sgf-dfun-state-index*)
1954       (gf-dfun-state generic-function)))
1955 (defun (setf safe-gf-dfun-state) (new-value generic-function)
1956   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1957       (setf (clos-slots-ref (get-slots generic-function)
1958                             *sgf-dfun-state-index*)
1959             new-value)
1960       (setf (gf-dfun-state generic-function) new-value)))
1961
1962 (defun set-dfun (gf &optional dfun cache info)
1963   (when cache
1964     (setf (cache-owner cache) gf))
1965   (let ((new-state (if (and dfun (or cache info))
1966                        (list* dfun cache info)
1967                        dfun)))
1968     (if (eq *boot-state* 'complete)
1969         (setf (safe-gf-dfun-state gf) new-state)
1970         (setf (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*)
1971               new-state)))
1972   dfun)
1973
1974 (defun gf-dfun-cache (gf)
1975   (let ((state (if (eq *boot-state* 'complete)
1976                    (safe-gf-dfun-state gf)
1977                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1978     (typecase state
1979       (function nil)
1980       (cons (cadr state)))))
1981
1982 (defun gf-dfun-info (gf)
1983   (let ((state (if (eq *boot-state* 'complete)
1984                    (safe-gf-dfun-state gf)
1985                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
1986     (typecase state
1987       (function nil)
1988       (cons (cddr state)))))
1989
1990 (defvar *sgf-name-index*
1991   (!bootstrap-slot-index 'standard-generic-function 'name))
1992
1993 (defun !early-gf-name (gf)
1994   (clos-slots-ref (get-slots gf) *sgf-name-index*))
1995
1996 (defun gf-lambda-list (gf)
1997   (let ((arg-info (if (eq *boot-state* 'complete)
1998                       (gf-arg-info gf)
1999                       (early-gf-arg-info gf))))
2000     (if (eq :no-lambda-list (arg-info-lambda-list arg-info))
2001         (let ((methods (if (eq *boot-state* 'complete)
2002                            (generic-function-methods gf)
2003                            (early-gf-methods gf))))
2004           (if (null methods)
2005               (progn
2006                 (warn "no way to determine the lambda list for ~S" gf)
2007                 nil)
2008               (let* ((method (car (last methods)))
2009                      (ll (if (consp method)
2010                              (early-method-lambda-list method)
2011                              (method-lambda-list method))))
2012                 (create-gf-lambda-list ll))))
2013         (arg-info-lambda-list arg-info))))
2014
2015 (defmacro real-ensure-gf-internal (gf-class all-keys env)
2016   `(progn
2017      (cond ((symbolp ,gf-class)
2018             (setq ,gf-class (find-class ,gf-class t ,env)))
2019            ((classp ,gf-class))
2020            (t
2021             (error "The :GENERIC-FUNCTION-CLASS argument (~S) was neither a~%~
2022                     class nor a symbol that names a class."
2023                    ,gf-class)))
2024      (unless (class-finalized-p ,gf-class)
2025        (if (class-has-a-forward-referenced-superclass-p ,gf-class)
2026            ;; FIXME: reference MOP documentation -- this is an
2027            ;; additional requirement on our users
2028            (error "The generic function class ~S is not finalizeable" ,gf-class)
2029            (finalize-inheritance ,gf-class)))
2030      (remf ,all-keys :generic-function-class)
2031      (remf ,all-keys :environment)
2032      (let ((combin (getf ,all-keys :method-combination '.shes-not-there.)))
2033        (unless (eq combin '.shes-not-there.)
2034          (setf (getf ,all-keys :method-combination)
2035                (find-method-combination (class-prototype ,gf-class)
2036                                         (car combin)
2037                                         (cdr combin)))))
2038     (let ((method-class (getf ,all-keys :method-class '.shes-not-there.)))
2039       (unless (eq method-class '.shes-not-there.)
2040         (setf (getf ,all-keys :method-class)
2041               (cond ((classp method-class)
2042                      method-class)
2043                     (t (find-class method-class t ,env))))))))
2044
2045 (defun real-ensure-gf-using-class--generic-function
2046        (existing
2047         fun-name
2048         &rest all-keys
2049         &key environment (lambda-list nil lambda-list-p)
2050              (generic-function-class 'standard-generic-function gf-class-p)
2051         &allow-other-keys)
2052   (real-ensure-gf-internal generic-function-class all-keys environment)
2053   (unless (or (null gf-class-p)
2054               (eq (class-of existing) generic-function-class))
2055     (change-class existing generic-function-class))
2056   (prog1
2057       (apply #'reinitialize-instance existing all-keys)
2058     (when lambda-list-p
2059       (proclaim (defgeneric-declaration fun-name lambda-list)))))
2060
2061 (defun real-ensure-gf-using-class--null
2062        (existing
2063         fun-name
2064         &rest all-keys
2065         &key environment (lambda-list nil lambda-list-p)
2066              (generic-function-class 'standard-generic-function)
2067         &allow-other-keys)
2068   (declare (ignore existing))
2069   (real-ensure-gf-internal generic-function-class all-keys environment)
2070   (prog1
2071       (setf (gdefinition fun-name)
2072             (apply #'make-instance generic-function-class
2073                    :name fun-name all-keys))
2074     (when lambda-list-p
2075       (proclaim (defgeneric-declaration fun-name lambda-list)))))
2076 \f
2077 (defun safe-gf-arg-info (generic-function)
2078   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2079       (clos-slots-ref (fsc-instance-slots generic-function)
2080                       *sgf-arg-info-index*)
2081       (gf-arg-info generic-function)))
2082
2083 ;;; FIXME: this function took on a slightly greater role than it
2084 ;;; previously had around 2005-11-02, when CSR fixed the bug whereby
2085 ;;; having more than one subclass of standard-generic-function caused
2086 ;;; the whole system to die horribly through a metacircle in
2087 ;;; GF-ARG-INFO.  The fix is to be slightly more disciplined about
2088 ;;; calling accessor methods -- we call GET-GENERIC-FUN-INFO when
2089 ;;; computing discriminating functions, so we need to be careful about
2090 ;;; having a base case for the recursion, and we provide that with the
2091 ;;; STANDARD-GENERIC-FUNCTION case below.  However, we are not (yet)
2092 ;;; as disciplined as CLISP's CLOS/MOP, and it would be nice to get to
2093 ;;; that stage, where all potentially dangerous cases are enumerated
2094 ;;; and stopped.  -- CSR, 2005-11-02.
2095 (defun get-generic-fun-info (gf)
2096   ;; values   nreq applyp metatypes nkeys arg-info
2097   (multiple-value-bind (applyp metatypes arg-info)
2098       (let* ((arg-info (if (early-gf-p gf)
2099                            (early-gf-arg-info gf)
2100                            (safe-gf-arg-info gf)))
2101              (metatypes (arg-info-metatypes arg-info)))
2102         (values (arg-info-applyp arg-info)
2103                 metatypes
2104                 arg-info))
2105     (values (length metatypes) applyp metatypes
2106             (count-if (lambda (x) (neq x t)) metatypes)
2107             arg-info)))
2108
2109 (defun early-make-a-method (class qualifiers arglist specializers initargs doc
2110                             &key slot-name object-class method-class-function)
2111   (initialize-method-function initargs)
2112   (let ((parsed ())
2113         (unparsed ()))
2114     ;; Figure out whether we got class objects or class names as the
2115     ;; specializers and set parsed and unparsed appropriately. If we
2116     ;; got class objects, then we can compute unparsed, but if we got
2117     ;; class names we don't try to compute parsed.
2118     ;;
2119     ;; Note that the use of not symbolp in this call to every should be
2120     ;; read as 'classp' we can't use classp itself because it doesn't
2121     ;; exist yet.
2122     (if (every (lambda (s) (not (symbolp s))) specializers)
2123         (setq parsed specializers
2124               unparsed (mapcar (lambda (s)
2125                                  (if (eq s t) t (class-name s)))
2126                                specializers))
2127         (setq unparsed specializers
2128               parsed ()))
2129     (list :early-method           ;This is an early method dammit!
2130
2131           (getf initargs :function)
2132           (getf initargs :fast-function)
2133
2134           parsed                  ;The parsed specializers. This is used
2135                                   ;by early-method-specializers to cache
2136                                   ;the parse. Note that this only comes
2137                                   ;into play when there is more than one
2138                                   ;early method on an early gf.
2139
2140           (append
2141            (list class        ;A list to which real-make-a-method
2142                  qualifiers      ;can be applied to make a real method
2143                  arglist    ;corresponding to this early one.
2144                  unparsed
2145                  initargs
2146                  doc)
2147            (when slot-name
2148              (list :slot-name slot-name :object-class object-class
2149                    :method-class-function method-class-function))))))
2150
2151 (defun real-make-a-method
2152        (class qualifiers lambda-list specializers initargs doc
2153         &rest args &key slot-name object-class method-class-function)
2154   (setq specializers (parse-specializers specializers))
2155   (if method-class-function
2156       (let* ((object-class (if (classp object-class) object-class
2157                                (find-class object-class)))
2158              (slots (class-direct-slots object-class))
2159              (slot-definition (find slot-name slots
2160                                     :key #'slot-definition-name)))
2161         (aver slot-name)
2162         (aver slot-definition)
2163         (let ((initargs (list* :qualifiers qualifiers :lambda-list lambda-list
2164                                :specializers specializers :documentation doc
2165                                :slot-definition slot-definition
2166                                :slot-name slot-name initargs)))
2167           (apply #'make-instance
2168                  (apply method-class-function object-class slot-definition
2169                         initargs)
2170                  initargs)))
2171       (apply #'make-instance class :qualifiers qualifiers
2172              :lambda-list lambda-list :specializers specializers
2173              :documentation doc (append args initargs))))
2174
2175 (defun early-method-function (early-method)
2176   (values (cadr early-method) (caddr early-method)))
2177
2178 (defun early-method-class (early-method)
2179   (find-class (car (fifth early-method))))
2180
2181 (defun early-method-standard-accessor-p (early-method)
2182   (let ((class (first (fifth early-method))))
2183     (or (eq class 'standard-reader-method)
2184         (eq class 'standard-writer-method)
2185         (eq class 'standard-boundp-method))))
2186
2187 (defun early-method-standard-accessor-slot-name (early-method)
2188   (eighth (fifth early-method)))
2189
2190 ;;; Fetch the specializers of an early method. This is basically just
2191 ;;; a simple accessor except that when the second argument is t, this
2192 ;;; converts the specializers from symbols into class objects. The
2193 ;;; class objects are cached in the early method, this makes
2194 ;;; bootstrapping faster because the class objects only have to be
2195 ;;; computed once.
2196 ;;;
2197 ;;; NOTE:
2198 ;;;  The second argument should only be passed as T by
2199 ;;;  early-lookup-method. This is to implement the rule that only when
2200 ;;;  there is more than one early method on a generic function is the
2201 ;;;  conversion from class names to class objects done. This
2202 ;;;  corresponds to the fact that we are only allowed to have one
2203 ;;;  method on any generic function up until the time classes exist.
2204 (defun early-method-specializers (early-method &optional objectsp)
2205   (if (and (listp early-method)
2206            (eq (car early-method) :early-method))
2207       (cond ((eq objectsp t)
2208              (or (fourth early-method)
2209                  (setf (fourth early-method)
2210                        (mapcar #'find-class (cadddr (fifth early-method))))))
2211             (t
2212              (fourth (fifth early-method))))
2213       (error "~S is not an early-method." early-method)))
2214
2215 (defun early-method-qualifiers (early-method)
2216   (second (fifth early-method)))
2217
2218 (defun early-method-lambda-list (early-method)
2219   (third (fifth early-method)))
2220
2221 (defun early-add-named-method (generic-function-name
2222                                qualifiers
2223                                specializers
2224                                arglist
2225                                &rest initargs)
2226   (let* ((gf (ensure-generic-function generic-function-name))
2227          (existing
2228            (dolist (m (early-gf-methods gf))
2229              (when (and (equal (early-method-specializers m) specializers)
2230                         (equal (early-method-qualifiers m) qualifiers))
2231                (return m))))
2232          (new (make-a-method 'standard-method
2233                              qualifiers
2234                              arglist
2235                              specializers
2236                              initargs
2237                              ())))
2238     (when existing (remove-method gf existing))
2239     (add-method gf new)))
2240
2241 ;;; This is the early version of ADD-METHOD. Later this will become a
2242 ;;; generic function. See !FIX-EARLY-GENERIC-FUNCTIONS which has
2243 ;;; special knowledge about ADD-METHOD.
2244 (defun add-method (generic-function method)
2245   (when (not (fsc-instance-p generic-function))
2246     (error "Early ADD-METHOD didn't get a funcallable instance."))
2247   (when (not (and (listp method) (eq (car method) :early-method)))
2248     (error "Early ADD-METHOD didn't get an early method."))
2249   (push method (early-gf-methods generic-function))
2250   (set-arg-info generic-function :new-method method)
2251   (unless (assoc (!early-gf-name generic-function)
2252                  *!generic-function-fixups*
2253                  :test #'equal)
2254     (update-dfun generic-function)))
2255
2256 ;;; This is the early version of REMOVE-METHOD. See comments on
2257 ;;; the early version of ADD-METHOD.
2258 (defun remove-method (generic-function method)
2259   (when (not (fsc-instance-p generic-function))
2260     (error "An early remove-method didn't get a funcallable instance."))
2261   (when (not (and (listp method) (eq (car method) :early-method)))
2262     (error "An early remove-method didn't get an early method."))
2263   (setf (early-gf-methods generic-function)
2264         (remove method (early-gf-methods generic-function)))
2265   (set-arg-info generic-function)
2266   (unless (assoc (!early-gf-name generic-function)
2267                  *!generic-function-fixups*
2268                  :test #'equal)
2269     (update-dfun generic-function)))
2270
2271 ;;; This is the early version of GET-METHOD. See comments on the early
2272 ;;; version of ADD-METHOD.
2273 (defun get-method (generic-function qualifiers specializers
2274                                     &optional (errorp t))
2275   (if (early-gf-p generic-function)
2276       (or (dolist (m (early-gf-methods generic-function))
2277             (when (and (or (equal (early-method-specializers m nil)
2278                                   specializers)
2279                            (equal (early-method-specializers m t)
2280                                   specializers))
2281                        (equal (early-method-qualifiers m) qualifiers))
2282               (return m)))
2283           (if errorp
2284               (error "can't get early method")
2285               nil))
2286       (real-get-method generic-function qualifiers specializers errorp)))
2287
2288 (defun !fix-early-generic-functions ()
2289   (let ((accessors nil))
2290     ;; Rearrange *!EARLY-GENERIC-FUNCTIONS* to speed up
2291     ;; FIX-EARLY-GENERIC-FUNCTIONS.
2292     (dolist (early-gf-spec *!early-generic-functions*)
2293       (when (every #'early-method-standard-accessor-p
2294                    (early-gf-methods (gdefinition early-gf-spec)))
2295         (push early-gf-spec accessors)))
2296     (dolist (spec (nconc accessors
2297                          '(accessor-method-slot-name
2298                            generic-function-methods
2299                            method-specializers
2300                            specializerp
2301                            specializer-type
2302                            specializer-class
2303                            slot-definition-location
2304                            slot-definition-name
2305                            class-slots
2306                            gf-arg-info
2307                            class-precedence-list
2308                            slot-boundp-using-class
2309                            (setf slot-value-using-class)
2310                            slot-value-using-class
2311                            structure-class-p
2312                            standard-class-p
2313                            funcallable-standard-class-p
2314                            specializerp)))
2315       (/show spec)
2316       (setq *!early-generic-functions*
2317             (cons spec
2318                   (delete spec *!early-generic-functions* :test #'equal))))
2319
2320     (dolist (early-gf-spec *!early-generic-functions*)
2321       (/show early-gf-spec)
2322       (let* ((gf (gdefinition early-gf-spec))
2323              (methods (mapcar (lambda (early-method)
2324                                 (let ((args (copy-list (fifth
2325                                                         early-method))))
2326                                   (setf (fourth args)
2327                                         (early-method-specializers
2328                                          early-method t))
2329                                   (apply #'real-make-a-method args)))
2330                               (early-gf-methods gf))))
2331         (setf (generic-function-method-class gf) *the-class-standard-method*)
2332         (setf (generic-function-method-combination gf)
2333               *standard-method-combination*)
2334         (set-methods gf methods)))
2335
2336     (dolist (fn *!early-functions*)
2337       (/show fn)
2338       (setf (gdefinition (car fn)) (fdefinition (caddr fn))))
2339
2340     (dolist (fixup *!generic-function-fixups*)
2341       (/show fixup)
2342       (let* ((fspec (car fixup))
2343              (gf (gdefinition fspec))
2344              (methods (mapcar (lambda (method)
2345                                 (let* ((lambda-list (first method))
2346                                        (specializers (second method))
2347                                        (method-fn-name (third method))
2348                                        (fn-name (or method-fn-name fspec))
2349                                        (fn (fdefinition fn-name))
2350                                        (initargs
2351                                         (list :function
2352                                               (set-fun-name
2353                                                (lambda (args next-methods)
2354                                                  (declare (ignore
2355                                                            next-methods))
2356                                                  (apply fn args))
2357                                                `(call ,fn-name)))))
2358                                   (declare (type function fn))
2359                                   (make-a-method 'standard-method
2360                                                  ()
2361                                                  lambda-list
2362                                                  specializers
2363                                                  initargs
2364                                                  nil)))
2365                               (cdr fixup))))
2366         (setf (generic-function-method-class gf) *the-class-standard-method*)
2367         (setf (generic-function-method-combination gf)
2368               *standard-method-combination*)
2369         (set-methods gf methods))))
2370   (/show "leaving !FIX-EARLY-GENERIC-FUNCTIONS"))
2371 \f
2372 ;;; PARSE-DEFMETHOD is used by DEFMETHOD to parse the &REST argument
2373 ;;; into the 'real' arguments. This is where the syntax of DEFMETHOD
2374 ;;; is really implemented.
2375 (defun parse-defmethod (cdr-of-form)
2376   (declare (list cdr-of-form))
2377   (let ((name (pop cdr-of-form))
2378         (qualifiers ())
2379         (spec-ll ()))
2380     (loop (if (and (car cdr-of-form) (atom (car cdr-of-form)))
2381               (push (pop cdr-of-form) qualifiers)
2382               (return (setq qualifiers (nreverse qualifiers)))))
2383     (setq spec-ll (pop cdr-of-form))
2384     (values name qualifiers spec-ll cdr-of-form)))
2385
2386 (defun parse-specializers (specializers)
2387   (declare (list specializers))
2388   (flet ((parse (spec)
2389            (let ((result (specializer-from-type spec)))
2390              (if (specializerp result)
2391                  result
2392                  (if (symbolp spec)
2393                      (error "~S was used as a specializer,~%~
2394                              but is not the name of a class."
2395                             spec)
2396                      (error "~S is not a legal specializer." spec))))))
2397     (mapcar #'parse specializers)))
2398
2399 (defun unparse-specializers (specializers-or-method)
2400   (if (listp specializers-or-method)
2401       (flet ((unparse (spec)
2402                (if (specializerp spec)
2403                    (let ((type (specializer-type spec)))
2404                      (if (and (consp type)
2405                               (eq (car type) 'class))
2406                          (let* ((class (cadr type))
2407                                 (class-name (class-name class)))
2408                            (if (eq class (find-class class-name nil))
2409                                class-name
2410                                type))
2411                          type))
2412                    (error "~S is not a legal specializer." spec))))
2413         (mapcar #'unparse specializers-or-method))
2414       (unparse-specializers (method-specializers specializers-or-method))))
2415
2416 (defun parse-method-or-spec (spec &optional (errorp t))
2417   (let (gf method name temp)
2418     (if (method-p spec)
2419         (setq method spec
2420               gf (method-generic-function method)
2421               temp (and gf (generic-function-name gf))
2422               name (if temp
2423                        (make-method-spec temp
2424                                          (method-qualifiers method)
2425                                          (unparse-specializers
2426                                           (method-specializers method)))
2427                        (make-symbol (format nil "~S" method))))
2428         (multiple-value-bind (gf-spec quals specls)
2429             (parse-defmethod spec)
2430           (and (setq gf (and (or errorp (fboundp gf-spec))
2431                              (gdefinition gf-spec)))
2432                (let ((nreq (compute-discriminating-function-arglist-info gf)))
2433                  (setq specls (append (parse-specializers specls)
2434                                       (make-list (- nreq (length specls))
2435                                                  :initial-element
2436                                                  *the-class-t*)))
2437                  (and
2438                    (setq method (get-method gf quals specls errorp))
2439                    (setq name
2440                          (make-method-spec
2441                           gf-spec quals (unparse-specializers specls))))))))
2442     (values gf method name)))
2443 \f
2444 (defun extract-parameters (specialized-lambda-list)
2445   (multiple-value-bind (parameters ignore1 ignore2)
2446       (parse-specialized-lambda-list specialized-lambda-list)
2447     (declare (ignore ignore1 ignore2))
2448     parameters))
2449
2450 (defun extract-lambda-list (specialized-lambda-list)
2451   (multiple-value-bind (ignore1 lambda-list ignore2)
2452       (parse-specialized-lambda-list specialized-lambda-list)
2453     (declare (ignore ignore1 ignore2))
2454     lambda-list))
2455
2456 (defun extract-specializer-names (specialized-lambda-list)
2457   (multiple-value-bind (ignore1 ignore2 specializers)
2458       (parse-specialized-lambda-list specialized-lambda-list)
2459     (declare (ignore ignore1 ignore2))
2460     specializers))
2461
2462 (defun extract-required-parameters (specialized-lambda-list)
2463   (multiple-value-bind (ignore1 ignore2 ignore3 required-parameters)
2464       (parse-specialized-lambda-list specialized-lambda-list)
2465     (declare (ignore ignore1 ignore2 ignore3))
2466     required-parameters))
2467
2468 (define-condition specialized-lambda-list-error
2469     (reference-condition simple-program-error)
2470   ()
2471   (:default-initargs :references (list '(:ansi-cl :section (3 4 3)))))
2472
2473 (defun parse-specialized-lambda-list
2474     (arglist
2475      &optional supplied-keywords (allowed-keywords '(&optional &rest &key &aux))
2476      &aux (specialized-lambda-list-keywords
2477            '(&optional &rest &key &allow-other-keys &aux)))
2478   (let ((arg (car arglist)))
2479     (cond ((null arglist) (values nil nil nil nil))
2480           ((eq arg '&aux)
2481            (values nil arglist nil nil))
2482           ((memq arg lambda-list-keywords)
2483            ;; non-standard lambda-list-keywords are errors.
2484            (unless (memq arg specialized-lambda-list-keywords)
2485              (error 'specialized-lambda-list-error
2486                     :format-control "unknown specialized-lambda-list ~
2487                                      keyword ~S~%"
2488                     :format-arguments (list arg)))
2489            ;; no multiple &rest x &rest bla specifying
2490            (when (memq arg supplied-keywords)
2491              (error 'specialized-lambda-list-error
2492                     :format-control "multiple occurrence of ~
2493                                      specialized-lambda-list keyword ~S~%"
2494                     :format-arguments (list arg)))
2495            ;; And no placing &key in front of &optional, either.
2496            (unless (memq arg allowed-keywords)
2497              (error 'specialized-lambda-list-error
2498                     :format-control "misplaced specialized-lambda-list ~
2499                                      keyword ~S~%"
2500                     :format-arguments (list arg)))
2501            ;; When we are at a lambda-list keyword, the parameters
2502            ;; don't include the lambda-list keyword; the lambda-list
2503            ;; does include the lambda-list keyword; and no
2504            ;; specializers are allowed to follow the lambda-list
2505            ;; keywords (at least for now).
2506            (multiple-value-bind (parameters lambda-list)
2507                (parse-specialized-lambda-list (cdr arglist)
2508                                               (cons arg supplied-keywords)
2509                                               (if (eq arg '&key)
2510                                                   (cons '&allow-other-keys
2511                                                         (cdr (member arg allowed-keywords)))
2512                                                 (cdr (member arg allowed-keywords))))
2513              (when (and (eq arg '&rest)
2514                         (or (null lambda-list)
2515                             (memq (car lambda-list)
2516                                   specialized-lambda-list-keywords)
2517                             (not (or (null (cadr lambda-list))
2518                                      (memq (cadr lambda-list)
2519                                            specialized-lambda-list-keywords)))))
2520                (error 'specialized-lambda-list-error
2521                       :format-control
2522                       "in a specialized-lambda-list, excactly one ~
2523                        variable must follow &REST.~%"
2524                       :format-arguments nil))
2525              (values parameters
2526                      (cons arg lambda-list)
2527                      ()
2528                      ())))
2529           (supplied-keywords
2530            ;; After a lambda-list keyword there can be no specializers.
2531            (multiple-value-bind (parameters lambda-list)
2532                (parse-specialized-lambda-list (cdr arglist)
2533                                               supplied-keywords
2534                                               allowed-keywords)
2535              (values (cons (if (listp arg) (car arg) arg) parameters)
2536                      (cons arg lambda-list)
2537                      ()
2538                      ())))
2539           (t
2540            (multiple-value-bind (parameters lambda-list specializers required)
2541                (parse-specialized-lambda-list (cdr arglist))
2542              (values (cons (if (listp arg) (car arg) arg) parameters)
2543                      (cons (if (listp arg) (car arg) arg) lambda-list)
2544                      (cons (if (listp arg) (cadr arg) t) specializers)
2545                      (cons (if (listp arg) (car arg) arg) required)))))))
2546 \f
2547 (setq *boot-state* 'early)
2548 \f
2549 ;;; FIXME: In here there was a #-CMU definition of SYMBOL-MACROLET
2550 ;;; which used %WALKER stuff. That suggests to me that maybe the code
2551 ;;; walker stuff was only used for implementing stuff like that; maybe
2552 ;;; it's not needed any more? Hunt down what it was used for and see.
2553
2554 (defmacro with-slots (slots instance &body body)
2555   (let ((in (gensym)))
2556     `(let ((,in ,instance))
2557        (declare (ignorable ,in))
2558        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2559                              (third instance)
2560                              instance)))
2561            (and (symbolp instance)
2562                 `((declare (%variable-rebinding ,in ,instance)))))
2563        ,in
2564        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2565                                    (let ((var-name
2566                                           (if (symbolp slot-entry)
2567                                               slot-entry
2568                                               (car slot-entry)))
2569                                          (slot-name
2570                                           (if (symbolp slot-entry)
2571                                               slot-entry
2572                                               (cadr slot-entry))))
2573                                      `(,var-name
2574                                        (slot-value ,in ',slot-name))))
2575                                  slots)
2576                         ,@body))))
2577
2578 (defmacro with-accessors (slots instance &body body)
2579   (let ((in (gensym)))
2580     `(let ((,in ,instance))
2581        (declare (ignorable ,in))
2582        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2583                              (third instance)
2584                              instance)))
2585            (and (symbolp instance)
2586                 `((declare (%variable-rebinding ,in ,instance)))))
2587        ,in
2588        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2589                                    (let ((var-name (car slot-entry))
2590                                          (accessor-name (cadr slot-entry)))
2591                                      `(,var-name (,accessor-name ,in))))
2592                                  slots)
2593           ,@body))))