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))
 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-nameoid
 610                  (if (and (typep specializer 'class)
 611                           (let ((name (class-name specializer)))
 612                             (and name (symbolp name)
 613                                  (eq specializer (find-class name nil)))))
 614                      (class-name specializer)
 615                      specializer))
 616                 (kind (info :type :kind specializer-nameoid)))
 617
 618            (flet ((specializer-nameoid-class ()
 619                     (typecase specializer-nameoid
 620                       (symbol (find-class specializer-nameoid nil))
 621                       (class specializer-nameoid)
 622                       (class-eq-specializer
 623                        (specializer-class specializer-nameoid))
 624                       (t nil))))
 625              (ecase kind
 626                ((:primitive) `(type ,specializer-nameoid ,parameter))
 627                ((:defined)
 628                 (let ((class (specializer-nameoid-class)))
 629                   ;; CLASS can be null here if the user has
 630                   ;; erroneously tried to use a defined type as a
 631                   ;; specializer; it can be a non-BUILT-IN-CLASS if
 632                   ;; the user defines a type and calls (SETF
 633                   ;; FIND-CLASS) in a consistent way.
 634                  (when (and class (typep class 'built-in-class))
 635                    `(type ,specializer-nameoid ,parameter))))
 636               ((:instance nil)
 637                (let ((class (specializer-nameoid-class)))
 638                  (cond
 639                    (class
 640                     (if (typep class '(or built-in-class structure-class))
 641                         `(type ,class ,parameter)
 642                         ;; don't declare CLOS classes as parameters;
 643                         ;; it's too expensive.
 644                         '(ignorable)))
 645                    (t
 646                     ;; we can get here, and still not have a failure
 647                     ;; case, by doing MOP programming like (PROGN
 648                     ;; (ENSURE-CLASS 'FOO) (DEFMETHOD BAR ((X FOO))
 649                     ;; ...)).  Best to let the user know we haven't
 650                     ;; been able to extract enough information:
 651                     (style-warn
 652                      "~@<can't find type for specializer ~S in ~S.~@:>"
 653                      specializer-nameoid
 654                      'parameter-specializer-declaration-in-defmethod)
 655                     '(ignorable)))))
 656               ((:forthcoming-defclass-type)
 657                '(ignorable))))))))
 658
 659 ;;; For passing a list (groveled by the walker) of the required
 660 ;;; parameters whose bindings are modified in the method body to the
 661 ;;; optimized-slot-value* macros.
 662 (define-symbol-macro %parameter-binding-modified ())
 663
 664 (defun make-method-lambda-internal (method-lambda &optional env)
 665   (unless (and (consp method-lambda) (eq (car method-lambda) 'lambda))
 666     (error "The METHOD-LAMBDA argument to MAKE-METHOD-LAMBDA, ~S, ~
 667             is not a lambda form."
 668            method-lambda))
 669   (multiple-value-bind (real-body declarations documentation)
 670       (parse-body (cddr method-lambda))
 671     (let* ((name-decl (get-declaration '%method-name declarations))
 672            (sll-decl (get-declaration '%method-lambda-list declarations))
 673            (method-name (when (consp name-decl) (car name-decl)))
 674            (generic-function-name (when method-name (car method-name)))
 675            (specialized-lambda-list (or sll-decl (cadr method-lambda))))
 676       (multiple-value-bind (parameters lambda-list specializers)
 677           (parse-specialized-lambda-list specialized-lambda-list)
 678         (let* ((required-parameters
 679                 (mapcar (lambda (r s) (declare (ignore s)) r)
 680                         parameters
 681                         specializers))
 682                (slots (mapcar #'list required-parameters))
 683                (calls (list nil))
 684                (class-declarations
 685                 `(declare
 686                   ;; These declarations seem to be used by PCL to pass
 687                   ;; information to itself; when I tried to delete 'em
 688                   ;; ca. 0.6.10 it didn't work. I'm not sure how
 689                   ;; they work, but note the (VAR-DECLARATION '%CLASS ..)
 690                   ;; expression in CAN-OPTIMIZE-ACCESS1. -- WHN 2000-12-30
 691                   ,@(remove nil
 692                             (mapcar (lambda (a s) (and (symbolp s)
 693                                                        (neq s t)
 694                                                        `(%class ,a ,s)))
 695                                     parameters
 696                                     specializers))
 697                   ;; These TYPE declarations weren't in the original
 698                   ;; PCL code, but the Python compiler likes them a
 699                   ;; lot. (We're telling the compiler about our
 700                   ;; knowledge of specialized argument types so that
 701                   ;; it can avoid run-time type dispatch overhead,
 702                   ;; which can be a huge win for Python.)
 703                   ;;
 704                   ;; KLUDGE: when I tried moving these to
 705                   ;; ADD-METHOD-DECLARATIONS, things broke.  No idea
 706                   ;; why.  -- CSR, 2004-06-16
 707                   ,@(mapcar #'parameter-specializer-declaration-in-defmethod
 708                             parameters
 709                             specializers)))
 710                (method-lambda
 711                 ;; Remove the documentation string and insert the
 712                 ;; appropriate class declarations. The documentation
 713                 ;; string is removed to make it easy for us to insert
 714                 ;; new declarations later, they will just go after the
 715                 ;; CADR of the method lambda. The class declarations
 716                 ;; are inserted to communicate the class of the method's
 717                 ;; arguments to the code walk.
 718                 `(lambda ,lambda-list
 719                    ;; The default ignorability of method parameters
 720                    ;; doesn't seem to be specified by ANSI. PCL had
 721                    ;; them basically ignorable but was a little
 722                    ;; inconsistent. E.g. even though the two
 723                    ;; method definitions
 724                    ;;   (DEFMETHOD FOO ((X T) (Y T)) "Z")
 725                    ;;   (DEFMETHOD FOO ((X T) Y) "Z")
 726                    ;; are otherwise equivalent, PCL treated Y as
 727                    ;; ignorable in the first definition but not in the
 728                    ;; second definition. We make all required
 729                    ;; parameters ignorable as a way of systematizing
 730                    ;; the old PCL behavior. -- WHN 2000-11-24
 731                    (declare (ignorable ,@required-parameters))
 732                    ,class-declarations
 733                    ,@declarations
 734                    (block ,(fun-name-block-name generic-function-name)
 735                      ,@real-body)))
 736                (constant-value-p (and (null (cdr real-body))
 737                                       (constantp (car real-body))))
 738                (constant-value (and constant-value-p
 739                                     (constant-form-value (car real-body))))
 740                (plist (and constant-value-p
 741                            (or (typep constant-value
 742                                       '(or number character))
 743                                (and (symbolp constant-value)
 744                                     (symbol-package constant-value)))
 745                            (list :constant-value constant-value)))
 746                (applyp (dolist (p lambda-list nil)
 747                          (cond ((memq p '(&optional &rest &key))
 748                                 (return t))
 749                                ((eq p '&aux)
 750                                 (return nil))))))
 751           (multiple-value-bind
 752                 (walked-lambda call-next-method-p closurep
 753                                next-method-p-p setq-p
 754                                parameters-setqd)
 755               (walk-method-lambda method-lambda
 756                                   required-parameters
 757                                   env
 758                                   slots
 759                                   calls)
 760             (multiple-value-bind (walked-lambda-body
 761                                   walked-declarations
 762                                   walked-documentation)
 763                 (parse-body (cddr walked-lambda))
 764               (declare (ignore walked-documentation))
 765               (when (some #'cdr slots)
 766                 (multiple-value-bind (slot-name-lists call-list)
 767                     (slot-name-lists-from-slots slots calls)
 768                   (setq plist
 769                         `(,@(when slot-name-lists
 770                                   `(:slot-name-lists ,slot-name-lists))
 771                             ,@(when call-list
 772                                     `(:call-list ,call-list))
 773                             ,@plist))
 774                   (setq walked-lambda-body
 775                         `((pv-binding (,required-parameters
 776                                        ,slot-name-lists
 777                                        (load-time-value
 778                                         (intern-pv-table
 779                                          :slot-name-lists ',slot-name-lists
 780                                          :call-list ',call-list)))
 781                             ,@walked-lambda-body)))))
 782               (when (and (memq '&key lambda-list)
 783                          (not (memq '&allow-other-keys lambda-list)))
 784                 (let ((aux (memq '&aux lambda-list)))
 785                   (setq lambda-list (nconc (ldiff lambda-list aux)
 786                                            (list '&allow-other-keys)
 787                                            aux))))
 788               (values `(lambda (.method-args. .next-methods.)
 789                          (simple-lexical-method-functions
 790                              (,lambda-list .method-args. .next-methods.
 791                                            :call-next-method-p
 792                                            ,call-next-method-p
 793                                            :next-method-p-p ,next-method-p-p
 794                                            :setq-p ,setq-p
 795                                            ;; we need to pass this along
 796                                            ;; so that NO-NEXT-METHOD can
 797                                            ;; be given a suitable METHOD
 798                                            ;; argument; we need the
 799                                            ;; QUALIFIERS and SPECIALIZERS
 800                                            ;; inside the declaration to
 801                                            ;; give to FIND-METHOD.
 802                                            :method-name-declaration ,name-decl
 803                                            :closurep ,closurep
 804                                            :applyp ,applyp)
 805                            ,@walked-declarations
 806                            (locally
 807                                (declare (disable-package-locks
 808                                          %parameter-binding-modified))
 809                              (symbol-macrolet ((%parameter-binding-modified
 810                                                 ',@parameters-setqd))
 811                                (declare (enable-package-locks
 812                                          %parameter-binding-modified))
 813                                ,@walked-lambda-body))))
 814                       `(,@(when plist
 815                                 `(plist ,plist))
 816                           ,@(when documentation
 817                                   `(:documentation ,documentation)))))))))))
 818
 819 (unless (fboundp 'make-method-lambda)
 820   (setf (gdefinition 'make-method-lambda)
 821         (symbol-function 'real-make-method-lambda)))
 822
 823 (defmacro simple-lexical-method-functions ((lambda-list
 824                                             method-args
 825                                             next-methods
 826                                             &rest lmf-options)
 827                                            &body body)
 828   `(progn
 829      ,method-args ,next-methods
 830      (bind-simple-lexical-method-functions (,method-args ,next-methods
 831                                                          ,lmf-options)
 832          (bind-args (,lambda-list ,method-args)
 833            ,@body))))
 834
 835 (defmacro fast-lexical-method-functions ((lambda-list
 836                                           next-method-call
 837                                           args
 838                                           rest-arg
 839                                           &rest lmf-options)
 840                                          &body body)
 841   `(bind-fast-lexical-method-functions (,args ,rest-arg ,next-method-call ,lmf-options)
 842      (bind-args (,(nthcdr (length args) lambda-list) ,rest-arg)
 843        ,@body)))
 844
 845 (defmacro bind-simple-lexical-method-functions
 846     ((method-args next-methods (&key call-next-method-p next-method-p-p setq-p
 847                                      closurep applyp method-name-declaration))
 848      &body body
 849      &environment env)
 850   (if (not (or call-next-method-p setq-p closurep next-method-p-p applyp))
 851       `(locally
 852            ,@body)
 853       `(let ((.next-method. (car ,next-methods))
 854              (,next-methods (cdr ,next-methods)))
 855          (declare (ignorable .next-method. ,next-methods))
 856          (flet (,@(and call-next-method-p
 857                        `((call-next-method
 858                           (&rest cnm-args)
 859                           ,@(if (safe-code-p env)
 860                                 `((%check-cnm-args cnm-args
 861                                                    ,method-args
 862                                                    ',method-name-declaration))
 863                                 nil)
 864                           (if .next-method.
 865                               (funcall (if (std-instance-p .next-method.)
 866                                            (method-function .next-method.)
 867                                            .next-method.) ; for early methods
 868                                        (or cnm-args ,method-args)
 869                                        ,next-methods)
 870                               (apply #'call-no-next-method
 871                                      ',method-name-declaration
 872                                      (or cnm-args ,method-args))))))
 873                 ,@(and next-method-p-p
 874                        '((next-method-p ()
 875                           (not (null .next-method.))))))
 876            ,@body))))
 877
 878 (defun call-no-next-method (method-name-declaration &rest args)
 879   (destructuring-bind (name) method-name-declaration
 880     (destructuring-bind (name &rest qualifiers-and-specializers) name
 881       ;; KLUDGE: inefficient traversal, but hey.  This should only
 882       ;; happen on the slow error path anyway.
 883       (let* ((qualifiers (butlast qualifiers-and-specializers))
 884              (specializers (car (last qualifiers-and-specializers)))
 885              (method (find-method (gdefinition name) qualifiers specializers)))
 886         (apply #'no-next-method
 887                (method-generic-function method)
 888                method
 889                args)))))
 890
 891 (defstruct (method-call (:copier nil))
 892   (function #'identity :type function)
 893   call-method-args)
 894 (defstruct (constant-method-call (:copier nil) (:include method-call))
 895   value)
 896
 897 #-sb-fluid (declaim (sb-ext:freeze-type method-call))
 898
 899 (defmacro invoke-method-call1 (function args cm-args)
 900   `(let ((.function. ,function)
 901          (.args. ,args)
 902          (.cm-args. ,cm-args))
 903      (if (and .cm-args. (null (cdr .cm-args.)))
 904          (funcall .function. .args. (car .cm-args.))
 905          (apply .function. .args. .cm-args.))))
 906
 907 (defmacro invoke-method-call (method-call restp &rest required-args+rest-arg)
 908   `(invoke-method-call1 (method-call-function ,method-call)
 909                         ,(if restp
 910                              `(list* ,@required-args+rest-arg)
 911                              `(list ,@required-args+rest-arg))
 912                         (method-call-call-method-args ,method-call)))
 913
 914 (defstruct (fast-method-call (:copier nil))
 915   (function #'identity :type function)
 916   pv-cell
 917   next-method-call
 918   arg-info)
 919 (defstruct (constant-fast-method-call
 920              (:copier nil) (:include fast-method-call))
 921   value)
 922
 923 #-sb-fluid (declaim (sb-ext:freeze-type fast-method-call))
 924
 925 ;; The two variants of INVOKE-FAST-METHOD-CALL differ in how REST-ARGs
 926 ;; are handled. The first one will get REST-ARG as a single list (as
 927 ;; the last argument), and will thus need to use APPLY. The second one
 928 ;; will get them as a &MORE argument, so we can pass the arguments
 929 ;; directly with MULTIPLE-VALUE-CALL and %MORE-ARG-VALUES.
 930
 931 (defmacro invoke-fast-method-call (method-call restp &rest required-args+rest-arg)
 932   `(,(if restp 'apply 'funcall) (fast-method-call-function ,method-call)
 933                                 (fast-method-call-pv-cell ,method-call)
 934                                 (fast-method-call-next-method-call ,method-call)
 935                                 ,@required-args+rest-arg))
 936
 937 (defmacro invoke-fast-method-call/more (method-call
 938                                         more-context
 939                                         more-count
 940                                         &rest required-args)
 941   (macrolet ((generate-call (n)
 942                ``(funcall (fast-method-call-function ,method-call)
 943                           (fast-method-call-pv-cell ,method-call)
 944                           (fast-method-call-next-method-call ,method-call)
 945                           ,@required-args
 946                           ,@(loop for x below ,n
 947                                   collect `(sb-c::%more-arg ,more-context ,x)))))
 948     ;; The cases with only small amounts of required arguments passed
 949     ;; are probably very common, and special-casing speeds them up by
 950     ;; a factor of 2 with very little effect on the other
 951     ;; cases. Though it'd be nice to have the generic case be equally
 952     ;; fast.
 953     `(case ,more-count
 954        (0 ,(generate-call 0))
 955        (1 ,(generate-call 1))
 956        (t (multiple-value-call (fast-method-call-function ,method-call)
 957             (values (fast-method-call-pv-cell ,method-call))
 958             (values (fast-method-call-next-method-call ,method-call))
 959             ,@required-args
 960             (sb-c::%more-arg-values ,more-context 0 ,more-count))))))
 961
 962 (defstruct (fast-instance-boundp (:copier nil))
 963   (index 0 :type fixnum))
 964
 965 #-sb-fluid (declaim (sb-ext:freeze-type fast-instance-boundp))
 966
 967 (eval-when (:compile-toplevel :load-toplevel :execute)
 968   (defvar *allow-emf-call-tracing-p* nil)
 969   (defvar *enable-emf-call-tracing-p* #-sb-show nil #+sb-show t))
 970 \f
 971 ;;;; effective method functions
 972
 973 (defvar *emf-call-trace-size* 200)
 974 (defvar *emf-call-trace* nil)
 975 (defvar *emf-call-trace-index* 0)
 976
 977 ;;; This function was in the CMU CL version of PCL (ca Debian 2.4.8)
 978 ;;; without explanation. It appears to be intended for debugging, so
 979 ;;; it might be useful someday, so I haven't deleted it.
 980 ;;; But it isn't documented and isn't used for anything now, so
 981 ;;; I've conditionalized it out of the base system. -- WHN 19991213
 982 #+sb-show
 983 (defun show-emf-call-trace ()
 984   (when *emf-call-trace*
 985     (let ((j *emf-call-trace-index*)
 986           (*enable-emf-call-tracing-p* nil))
 987       (format t "~&(The oldest entries are printed first)~%")
 988       (dotimes-fixnum (i *emf-call-trace-size*)
 989         (let ((ct (aref *emf-call-trace* j)))
 990           (when ct (print ct)))
 991         (incf j)
 992         (when (= j *emf-call-trace-size*)
 993           (setq j 0))))))
 994
 995 (defun trace-emf-call-internal (emf format args)
 996   (unless *emf-call-trace*
 997     (setq *emf-call-trace* (make-array *emf-call-trace-size*)))
 998   (setf (aref *emf-call-trace* *emf-call-trace-index*)
 999         (list* emf format args))
1000   (incf *emf-call-trace-index*)
1001   (when (= *emf-call-trace-index* *emf-call-trace-size*)
1002     (setq *emf-call-trace-index* 0)))
1003
1004 (defmacro trace-emf-call (emf format args)
1005   (when *allow-emf-call-tracing-p*
1006     `(when *enable-emf-call-tracing-p*
1007        (trace-emf-call-internal ,emf ,format ,args))))
1008
1009 (defmacro invoke-effective-method-function-fast
1010     (emf restp &key required-args rest-arg more-arg)
1011   `(progn
1012      (trace-emf-call ,emf ,restp (list ,@required-args rest-arg))
1013      ,(if more-arg
1014           `(invoke-fast-method-call/more ,emf
1015                                          ,@more-arg
1016                                          ,@required-args)
1017           `(invoke-fast-method-call ,emf
1018                                     ,restp
1019                                     ,@required-args
1020                                     ,@rest-arg))))
1021
1022 (defun effective-method-optimized-slot-access-clause
1023     (emf restp required-args)
1024   ;; "What," you may wonder, "do these next two clauses do?" In that
1025   ;; case, you are not a PCL implementor, for they considered this to
1026   ;; be self-documenting.:-| Or CSR, for that matter, since he can
1027   ;; also figure it out by looking at it without breaking stride. For
1028   ;; the rest of us, though: From what the code is doing with .SLOTS.
1029   ;; and whatnot, evidently it's implementing SLOT-VALUEish and
1030   ;; GET-SLOT-VALUEish things. Then we can reason backwards and
1031   ;; conclude that setting EMF to a FIXNUM is an optimized way to
1032   ;; represent these slot access operations.
1033   (when (not restp)
1034     (let ((length (length required-args)))
1035       (cond ((= 1 length)
1036              `((fixnum
1037                 (let* ((.slots. (get-slots-or-nil
1038                                  ,(car required-args)))
1039                        (value (when .slots. (clos-slots-ref .slots. ,emf))))
1040                   (if (eq value +slot-unbound+)
1041                       (slot-unbound-internal ,(car required-args)
1042                                              ,emf)
1043                       value)))))
1044             ((= 2 length)
1045              `((fixnum
1046                 (let ((.new-value. ,(car required-args))
1047                       (.slots. (get-slots-or-nil
1048                                 ,(cadr required-args))))
1049                   (when .slots.
1050                     (setf (clos-slots-ref .slots. ,emf) .new-value.)))))))
1051       ;; (In cmucl-2.4.8 there was a commented-out third ,@(WHEN
1052       ;; ...) clause here to handle SLOT-BOUNDish stuff. Since
1053       ;; there was no explanation and presumably the code is 10+
1054       ;; years stale, I simply deleted it. -- WHN)
1055       )))
1056
1057 ;;; Before SBCL 0.9.16.7 instead of
1058 ;;; INVOKE-NARROW-EFFECTIVE-METHOD-FUNCTION we passed a (THE (OR
1059 ;;; FUNCTION METHOD-CALL FAST-METHOD-CALL) EMF) form as the EMF. Now,
1060 ;;; to make less work for the compiler we take a path that doesn't
1061 ;;; involve the slot-accessor clause (where EMF is a FIXNUM) at all.
1062 (macrolet ((def (name &optional narrow)
1063              `(defmacro ,name (emf restp &key required-args rest-arg more-arg)
1064                 (unless (constantp restp)
1065                   (error "The RESTP argument is not constant."))
1066                 (setq restp (constant-form-value restp))
1067                 (with-unique-names (emf-n)
1068                   `(locally
1069                        (declare (optimize (sb-c:insert-step-conditions 0)))
1070                      (let ((,emf-n ,emf))
1071                        (trace-emf-call ,emf-n ,restp (list ,@required-args ,@rest-arg))
1072                        (etypecase ,emf-n
1073                          (fast-method-call
1074                           ,(if more-arg
1075                                `(invoke-fast-method-call/more ,emf-n
1076                                                               ,@more-arg
1077                                                               ,@required-args)
1078                                `(invoke-fast-method-call ,emf-n
1079                                                          ,restp
1080                                                          ,@required-args
1081                                                          ,@rest-arg)))
1082                          ,@,(unless narrow
1083                               `(effective-method-optimized-slot-access-clause
1084                                 emf-n restp required-args))
1085                          (method-call
1086                           (invoke-method-call ,emf-n ,restp ,@required-args
1087                                               ,@rest-arg))
1088                          (function
1089                           ,(if restp
1090                                `(apply ,emf-n ,@required-args ,@rest-arg)
1091                                `(funcall ,emf-n ,@required-args
1092                                          ,@rest-arg))))))))))
1093   (def invoke-effective-method-function nil)
1094   (def invoke-narrow-effective-method-function t))
1095
1096 (defun invoke-emf (emf args)
1097   (trace-emf-call emf t args)
1098   (etypecase emf
1099     (fast-method-call
1100      (let* ((arg-info (fast-method-call-arg-info emf))
1101             (restp (cdr arg-info))
1102             (nreq (car arg-info)))
1103        (if restp
1104            (apply (fast-method-call-function emf)
1105                   (fast-method-call-pv-cell emf)
1106                   (fast-method-call-next-method-call emf)
1107                   args)
1108            (cond ((null args)
1109                   (if (eql nreq 0)
1110                       (invoke-fast-method-call emf nil)
1111                       (error 'simple-program-error
1112                              :format-control "invalid number of arguments: 0"
1113                              :format-arguments nil)))
1114                  ((null (cdr args))
1115                   (if (eql nreq 1)
1116                       (invoke-fast-method-call emf nil (car args))
1117                       (error 'simple-program-error
1118                              :format-control "invalid number of arguments: 1"
1119                              :format-arguments nil)))
1120                  ((null (cddr args))
1121                   (if (eql nreq 2)
1122                       (invoke-fast-method-call emf nil (car args) (cadr args))
1123                       (error 'simple-program-error
1124                              :format-control "invalid number of arguments: 2"
1125                              :format-arguments nil)))
1126                  (t
1127                   (apply (fast-method-call-function emf)
1128                          (fast-method-call-pv-cell emf)
1129                          (fast-method-call-next-method-call emf)
1130                          args))))))
1131     (method-call
1132      (apply (method-call-function emf)
1133             args
1134             (method-call-call-method-args emf)))
1135     (fixnum
1136      (cond ((null args)
1137             (error 'simple-program-error
1138                    :format-control "invalid number of arguments: 0"
1139                    :format-arguments nil))
1140            ((null (cdr args))
1141             (let* ((slots (get-slots (car args)))
1142                    (value (clos-slots-ref slots emf)))
1143               (if (eq value +slot-unbound+)
1144                   (slot-unbound-internal (car args) emf)
1145                   value)))
1146            ((null (cddr args))
1147             (setf (clos-slots-ref (get-slots (cadr args)) emf)
1148                   (car args)))
1149            (t (error 'simple-program-error
1150                      :format-control "invalid number of arguments"
1151                      :format-arguments nil))))
1152     (fast-instance-boundp
1153      (if (or (null args) (cdr args))
1154          (error 'simple-program-error
1155                 :format-control "invalid number of arguments"
1156                 :format-arguments nil)
1157          (let ((slots (get-slots (car args))))
1158            (not (eq (clos-slots-ref slots (fast-instance-boundp-index emf))
1159                     +slot-unbound+)))))
1160     (function
1161      (apply emf args))))
1162 \f
1163
1164 (defmacro fast-call-next-method-body ((args next-method-call rest-arg)
1165                                       method-name-declaration
1166                                       cnm-args)
1167   `(if ,next-method-call
1168        ,(let ((call `(invoke-narrow-effective-method-function
1169                       ,next-method-call
1170                       ,(not (null rest-arg))
1171                       :required-args ,args
1172                       :rest-arg ,(when rest-arg (list rest-arg)))))
1173              `(if ,cnm-args
1174                   (bind-args ((,@args
1175                                ,@(when rest-arg
1176                                        `(&rest ,rest-arg)))
1177                               ,cnm-args)
1178                     ,call)
1179                   ,call))
1180        (call-no-next-method ',method-name-declaration
1181                             ,@args
1182                             ,@(when rest-arg
1183                                     `(,rest-arg)))))
1184
1185 (defmacro bind-fast-lexical-method-functions
1186     ((args rest-arg next-method-call (&key
1187                                       call-next-method-p
1188                                       setq-p
1189                                       method-name-declaration
1190                                       next-method-p-p
1191                                       closurep
1192                                       applyp))
1193      &body body
1194      &environment env)
1195   (let* ((all-params (append args (when rest-arg (list rest-arg))))
1196          (rebindings (when (or setq-p call-next-method-p)
1197                        (mapcar (lambda (x) (list x x)) all-params))))
1198     (if (not (or call-next-method-p setq-p closurep next-method-p-p applyp))
1199         `(locally
1200              ,@body)
1201         `(flet (,@(when call-next-method-p
1202                         `((call-next-method (&rest cnm-args)
1203                             (declare (muffle-conditions code-deletion-note)
1204                                      (optimize (sb-c:insert-step-conditions 0)))
1205                            ,@(if (safe-code-p env)
1206                                  `((%check-cnm-args cnm-args (list ,@args)
1207                                                     ',method-name-declaration))
1208                                  nil)
1209                            (fast-call-next-method-body (,args
1210                                                         ,next-method-call
1211                                                         ,rest-arg)
1212                                                         ,method-name-declaration
1213                                                        cnm-args))))
1214                 ,@(when next-method-p-p
1215                         `((next-method-p ()
1216                            (declare (optimize (sb-c:insert-step-conditions 0)))
1217                            (not (null ,next-method-call))))))
1218            (let ,rebindings
1219              ,@(when rebindings `((declare (ignorable ,@all-params))))
1220              ,@body)))))
1221
1222 ;;; CMUCL comment (Gerd Moellmann):
1223 ;;;
1224 ;;; The standard says it's an error if CALL-NEXT-METHOD is called with
1225 ;;; arguments, and the set of methods applicable to those arguments is
1226 ;;; different from the set of methods applicable to the original
1227 ;;; method arguments.  (According to Barry Margolin, this rule was
1228 ;;; probably added to ensure that before and around methods are always
1229 ;;; run before primary methods.)
1230 ;;;
1231 ;;; This could be optimized for the case that the generic function
1232 ;;; doesn't have hairy methods, does have standard method combination,
1233 ;;; is a standard generic function, there are no methods defined on it
1234 ;;; for COMPUTE-APPLICABLE-METHODS and probably a lot more of such
1235 ;;; preconditions.  That looks hairy and is probably not worth it,
1236 ;;; because this check will never be fast.
1237 (defun %check-cnm-args (cnm-args orig-args method-name-declaration)
1238   (when cnm-args
1239     (let* ((gf (fdefinition (caar method-name-declaration)))
1240            (omethods (compute-applicable-methods gf orig-args))
1241            (nmethods (compute-applicable-methods gf cnm-args)))
1242       (unless (equal omethods nmethods)
1243         (error "~@<The set of methods ~S applicable to argument~P ~
1244                 ~{~S~^, ~} to call-next-method is different from ~
1245                 the set of methods ~S applicable to the original ~
1246                 method argument~P ~{~S~^, ~}.~@:>"
1247                nmethods (length cnm-args) cnm-args omethods
1248                (length orig-args) orig-args)))))
1249
1250 (defmacro bind-args ((lambda-list args) &body body)
1251   (let ((args-tail '.args-tail.)
1252         (key '.key.)
1253         (state 'required))
1254     (flet ((process-var (var)
1255              (if (memq var lambda-list-keywords)
1256                  (progn
1257                    (case var
1258                      (&optional       (setq state 'optional))
1259                      (&key            (setq state 'key))
1260                      (&allow-other-keys)
1261                      (&rest           (setq state 'rest))
1262                      (&aux            (setq state 'aux))
1263                      (otherwise
1264                       (error
1265                        "encountered the non-standard lambda list keyword ~S"
1266                        var)))
1267                    nil)
1268                  (case state
1269                    (required `((,var (pop ,args-tail))))
1270                    (optional (cond ((not (consp var))
1271                                     `((,var (when ,args-tail
1272                                               (pop ,args-tail)))))
1273                                    ((null (cddr var))
1274                                     `((,(car var) (if ,args-tail
1275                                                       (pop ,args-tail)
1276                                                       ,(cadr var)))))
1277                                    (t
1278                                     `((,(caddr var) (not (null ,args-tail)))
1279                                       (,(car var) (if ,args-tail
1280                                                       (pop ,args-tail)
1281                                                       ,(cadr var)))))))
1282                    (rest `((,var ,args-tail)))
1283                    (key (cond ((not (consp var))
1284                                `((,var (car
1285                                         (get-key-arg-tail ,(keywordicate var)
1286                                                           ,args-tail)))))
1287                               ((null (cddr var))
1288                                (multiple-value-bind (keyword variable)
1289                                    (if (consp (car var))
1290                                        (values (caar var)
1291                                                (cadar var))
1292                                        (values (keywordicate (car var))
1293                                                (car var)))
1294                                  `((,key (get-key-arg-tail ',keyword
1295                                                            ,args-tail))
1296                                    (,variable (if ,key
1297                                                   (car ,key)
1298                                                   ,(cadr var))))))
1299                               (t
1300                                (multiple-value-bind (keyword variable)
1301                                    (if (consp (car var))
1302                                        (values (caar var)
1303                                                (cadar var))
1304                                        (values (keywordicate (car var))
1305                                                (car var)))
1306                                  `((,key (get-key-arg-tail ',keyword
1307                                                            ,args-tail))
1308                                    (,(caddr var) (not (null,key)))
1309                                    (,variable (if ,key
1310                                                   (car ,key)
1311                                                   ,(cadr var))))))))
1312                    (aux `(,var))))))
1313       (let ((bindings (mapcan #'process-var lambda-list)))
1314         `(let* ((,args-tail ,args)
1315                 ,@bindings
1316                 (.dummy0.
1317                  ,@(when (eq state 'optional)
1318                      `((unless (null ,args-tail)
1319                          (error 'simple-program-error
1320                                 :format-control "surplus arguments: ~S"
1321                                 :format-arguments (list ,args-tail)))))))
1322            (declare (ignorable ,args-tail .dummy0.))
1323            ,@body)))))
1324
1325 (defun get-key-arg-tail (keyword list)
1326   (loop for (key . tail) on list by #'cddr
1327         when (null tail) do
1328           ;; FIXME: Do we want to export this symbol? Or maybe use an
1329           ;; (ERROR 'SIMPLE-PROGRAM-ERROR) form?
1330           (sb-c::%odd-key-args-error)
1331         when (eq key keyword)
1332           return tail))
1333
1334 (defun walk-method-lambda (method-lambda required-parameters env slots calls)
1335   (let (;; flag indicating that CALL-NEXT-METHOD should be in the
1336         ;; method definition
1337         (call-next-method-p nil)
1338         ;; flag indicating that #'CALL-NEXT-METHOD was seen in the
1339         ;; body of a method
1340         (closurep nil)
1341         ;; flag indicating that NEXT-METHOD-P should be in the method
1342         ;; definition
1343         (next-method-p-p nil)
1344         ;; a list of all required parameters whose bindings might be
1345         ;; modified in the method body.
1346         (parameters-setqd nil))
1347     (flet ((walk-function (form context env)
1348              (cond ((not (eq context :eval)) form)
1349                    ;; FIXME: Jumping to a conclusion from the way it's used
1350                    ;; above, perhaps CONTEXT should be called SITUATION
1351                    ;; (after the term used in the ANSI specification of
1352                    ;; EVAL-WHEN) and given modern ANSI keyword values
1353                    ;; like :LOAD-TOPLEVEL.
1354                    ((not (listp form)) form)
1355                    ((eq (car form) 'call-next-method)
1356                     (setq call-next-method-p t)
1357                     form)
1358                    ((eq (car form) 'next-method-p)
1359                     (setq next-method-p-p t)
1360                     form)
1361                    ((memq (car form) '(setq multiple-value-setq))
1362                     ;; FIXME: this is possibly a little strong as
1363                     ;; conditions go.  Ideally we would want to detect
1364                     ;; which, if any, of the method parameters are
1365                     ;; being set, and communicate that information to
1366                     ;; e.g. SPLIT-DECLARATIONS.  However, the brute
1367                     ;; force method doesn't really cost much; a little
1368                     ;; loss of discrimination over IGNORED variables
1369                     ;; should be all.  -- CSR, 2004-07-01
1370                     ;;
1371                     ;; As of 2006-09-18 modified parameter bindings
1372                     ;; are now tracked with more granularity than just
1373                     ;; one SETQ-P flag, in order to disable SLOT-VALUE
1374                     ;; optimizations for parameters that are SETQd.
1375                     ;; The old binary SETQ-P flag is still used for
1376                     ;; all other purposes, since as noted above, the
1377                     ;; extra cost is minimal. -- JES, 2006-09-18
1378                     ;;
1379                     ;; The walker will split (SETQ A 1 B 2) to
1380                     ;; separate (SETQ A 1) and (SETQ B 2) forms, so we
1381                     ;; only need to handle the simple case of SETQ
1382                     ;; here.
1383                     (let ((vars (if (eq (car form) 'setq)
1384                                     (list (second form))
1385                                     (second form))))
1386                       (dolist (var vars)
1387                         ;; Note that we don't need to check for
1388                         ;; %VARIABLE-REBINDING declarations like is
1389                         ;; done in CAN-OPTIMIZE-ACCESS1, since the
1390                         ;; bindings that will have that declation will
1391                         ;; never be SETQd.
1392                         (when (var-declaration '%class var env)
1393                           ;; If a parameter binding is shadowed by
1394                           ;; another binding it won't have a %CLASS
1395                           ;; declaration anymore, and this won't get
1396                           ;; executed.
1397                           (pushnew var parameters-setqd))))
1398                     form)
1399                    ((and (eq (car form) 'function)
1400                          (cond ((eq (cadr form) 'call-next-method)
1401                                 (setq call-next-method-p t)
1402                                 (setq closurep t)
1403                                 form)
1404                                ((eq (cadr form) 'next-method-p)
1405                                 (setq next-method-p-p t)
1406                                 (setq closurep t)
1407                                 form)
1408                                (t nil))))
1409                    ((and (memq (car form)
1410                                '(slot-value set-slot-value slot-boundp))
1411                          (constantp (caddr form)))
1412                     (let ((parameter (can-optimize-access form
1413                                                           required-parameters
1414                                                           env)))
1415                       (let ((fun (ecase (car form)
1416                                    (slot-value #'optimize-slot-value)
1417                                    (set-slot-value #'optimize-set-slot-value)
1418                                    (slot-boundp #'optimize-slot-boundp))))
1419                         (funcall fun slots parameter form))))
1420                    (t form))))
1421
1422       (let ((walked-lambda (walk-form method-lambda env #'walk-function)))
1423         ;;; FIXME: the walker's rewriting of the source code causes
1424         ;;; trouble when doing code coverage. The rewrites should be
1425         ;;; removed, and the same operations done using
1426         ;;; compiler-macros or tranforms.
1427         (values (if (sb-c:policy env (= sb-c:store-coverage-data 0))
1428                     walked-lambda
1429                     method-lambda)
1430                 call-next-method-p
1431                 closurep
1432                 next-method-p-p
1433                 (not (null parameters-setqd))
1434                 parameters-setqd)))))
1435
1436 (defun generic-function-name-p (name)
1437   (and (legal-fun-name-p name)
1438        (fboundp name)
1439        (if (eq *boot-state* 'complete)
1440            (standard-generic-function-p (gdefinition name))
1441            (funcallable-instance-p (gdefinition name)))))
1442 \f
1443 (defun method-plist-value (method key &optional default)
1444   (let ((plist (if (consp method)
1445                    (getf (early-method-initargs method) 'plist)
1446                    (object-plist method))))
1447     (getf plist key default)))
1448
1449 (defun (setf method-plist-value) (new-value method key &optional default)
1450   (if (consp method)
1451       (setf (getf (getf (early-method-initargs method) 'plist) key default)
1452             new-value)
1453       (setf (getf (object-plist method) key default) new-value)))
1454 \f
1455 (defun load-defmethod
1456     (class name quals specls ll initargs source-location)
1457   (setq initargs (copy-tree initargs))
1458   (setf (getf (getf initargs 'plist) :name)
1459         (make-method-spec name quals specls))
1460   (load-defmethod-internal class name quals specls
1461                            ll initargs source-location))
1462
1463 (defun load-defmethod-internal
1464     (method-class gf-spec qualifiers specializers lambda-list
1465                   initargs source-location)
1466   (when (and (eq *boot-state* 'complete)
1467              (fboundp gf-spec))
1468     (let* ((gf (fdefinition gf-spec))
1469            (method (and (generic-function-p gf)
1470                         (generic-function-methods gf)
1471                         (find-method gf
1472                                      qualifiers
1473                                      (parse-specializers specializers)
1474                                      nil))))
1475       (when method
1476         (style-warn "redefining ~S~{ ~S~} ~S in DEFMETHOD"
1477                     gf-spec qualifiers specializers))))
1478   (let ((method (apply #'add-named-method
1479                        gf-spec qualifiers specializers lambda-list
1480                        :definition-source source-location
1481                        initargs)))
1482     (unless (or (eq method-class 'standard-method)
1483                 (eq (find-class method-class nil) (class-of method)))
1484       ;; FIXME: should be STYLE-WARNING?
1485       (format *error-output*
1486               "~&At the time the method with qualifiers ~:S and~%~
1487                specializers ~:S on the generic function ~S~%~
1488                was compiled, the method-class for that generic function was~%~
1489                ~S. But, the method class is now ~S, this~%~
1490                may mean that this method was compiled improperly.~%"
1491               qualifiers specializers gf-spec
1492               method-class (class-name (class-of method))))
1493     method))
1494
1495 (defun make-method-spec (gf-spec qualifiers unparsed-specializers)
1496   `(slow-method ,gf-spec ,@qualifiers ,unparsed-specializers))
1497
1498 (defun initialize-method-function (initargs method)
1499   (let* ((mf (getf initargs :function))
1500          (mff (and (typep mf '%method-function)
1501                    (%method-function-fast-function mf)))
1502          (plist (getf initargs 'plist))
1503          (name (getf plist :name)))
1504     (when name
1505       (when mf
1506         (setq mf (set-fun-name mf name)))
1507       (when (and mff (consp name) (eq (car name) 'slow-method))
1508         (let ((fast-name `(fast-method ,@(cdr name))))
1509           (set-fun-name mff fast-name))))
1510     (when plist
1511       (let ((plist plist))
1512         (let ((snl (getf plist :slot-name-lists))
1513               (cl (getf plist :call-list)))
1514           (when (or snl cl)
1515             (setf (method-plist-value method :pv-table)
1516                   (intern-pv-table :slot-name-lists snl :call-list cl))))))))
1517 \f
1518 (defun analyze-lambda-list (lambda-list)
1519   (flet (;; FIXME: Is this redundant with SB-C::MAKE-KEYWORD-FOR-ARG?
1520          (parse-key-arg (arg)
1521            (if (listp arg)
1522                (if (listp (car arg))
1523                    (caar arg)
1524                    (keywordicate (car arg)))
1525                (keywordicate arg))))
1526     (let ((nrequired 0)
1527           (noptional 0)
1528           (keysp nil)
1529           (restp nil)
1530           (nrest 0)
1531           (allow-other-keys-p nil)
1532           (keywords ())
1533           (keyword-parameters ())
1534           (state 'required))
1535       (dolist (x lambda-list)
1536         (if (memq x lambda-list-keywords)
1537             (case x
1538               (&optional         (setq state 'optional))
1539               (&key              (setq keysp t
1540                                        state 'key))
1541               (&allow-other-keys (setq allow-other-keys-p t))
1542               (&rest             (setq restp t
1543                                        state 'rest))
1544               (&aux           (return t))
1545               (otherwise
1546                 (error "encountered the non-standard lambda list keyword ~S"
1547                        x)))
1548             (ecase state
1549               (required  (incf nrequired))
1550               (optional  (incf noptional))
1551               (key       (push (parse-key-arg x) keywords)
1552                          (push x keyword-parameters))
1553               (rest      (incf nrest)))))
1554       (when (and restp (zerop nrest))
1555         (error "Error in lambda-list:~%~
1556                 After &REST, a DEFGENERIC lambda-list ~
1557                 must be followed by at least one variable."))
1558       (values nrequired noptional keysp restp allow-other-keys-p
1559               (reverse keywords)
1560               (reverse keyword-parameters)))))
1561
1562 (defun keyword-spec-name (x)
1563   (let ((key (if (atom x) x (car x))))
1564     (if (atom key)
1565         (keywordicate key)
1566         (car key))))
1567
1568 (defun ftype-declaration-from-lambda-list (lambda-list name)
1569   (multiple-value-bind (nrequired noptional keysp restp allow-other-keys-p
1570                                   keywords keyword-parameters)
1571       (analyze-lambda-list lambda-list)
1572     (declare (ignore keyword-parameters))
1573     (let* ((old (info :function :type name)) ;FIXME:FDOCUMENTATION instead?
1574            (old-ftype (if (fun-type-p old) old nil))
1575            (old-restp (and old-ftype (fun-type-rest old-ftype)))
1576            (old-keys (and old-ftype
1577                           (mapcar #'key-info-name
1578                                   (fun-type-keywords
1579                                    old-ftype))))
1580            (old-keysp (and old-ftype (fun-type-keyp old-ftype)))
1581            (old-allowp (and old-ftype
1582                             (fun-type-allowp old-ftype)))
1583            (keywords (union old-keys (mapcar #'keyword-spec-name keywords))))
1584       `(function ,(append (make-list nrequired :initial-element t)
1585                           (when (plusp noptional)
1586                             (append '(&optional)
1587                                     (make-list noptional :initial-element t)))
1588                           (when (or restp old-restp)
1589                             '(&rest t))
1590                           (when (or keysp old-keysp)
1591                             (append '(&key)
1592                                     (mapcar (lambda (key)
1593                                               `(,key t))
1594                                             keywords)
1595                                     (when (or allow-other-keys-p old-allowp)
1596                                       '(&allow-other-keys)))))
1597                  *))))
1598
1599 (defun defgeneric-declaration (spec lambda-list)
1600   `(ftype ,(ftype-declaration-from-lambda-list lambda-list spec) ,spec))
1601 \f
1602 ;;;; early generic function support
1603
1604 (defvar *!early-generic-functions* ())
1605
1606 (defun ensure-generic-function (fun-name
1607                                 &rest all-keys
1608                                 &key environment source-location
1609                                 &allow-other-keys)
1610   (declare (ignore environment))
1611   (let ((existing (and (fboundp fun-name)
1612                        (gdefinition fun-name))))
1613     (cond ((and existing
1614                 (eq *boot-state* 'complete)
1615                 (null (generic-function-p existing)))
1616            (generic-clobbers-function fun-name)
1617            (fmakunbound fun-name)
1618            (apply #'ensure-generic-function fun-name all-keys))
1619           (t
1620            (apply #'ensure-generic-function-using-class
1621                   existing fun-name all-keys)))))
1622
1623 (defun generic-clobbers-function (fun-name)
1624   (cerror "Replace the function binding"
1625           'simple-program-error
1626           :format-control "~S already names an ordinary function or a macro."
1627           :format-arguments (list fun-name)))
1628
1629 (defvar *sgf-wrapper*
1630   (boot-make-wrapper (early-class-size 'standard-generic-function)
1631                      'standard-generic-function))
1632
1633 (defvar *sgf-slots-init*
1634   (mapcar (lambda (canonical-slot)
1635             (if (memq (getf canonical-slot :name) '(arg-info source))
1636                 +slot-unbound+
1637                 (let ((initfunction (getf canonical-slot :initfunction)))
1638                   (if initfunction
1639                       (funcall initfunction)
1640                       +slot-unbound+))))
1641           (early-collect-inheritance 'standard-generic-function)))
1642
1643 (defvar *sgf-method-class-index*
1644   (!bootstrap-slot-index 'standard-generic-function 'method-class))
1645
1646 (defun early-gf-p (x)
1647   (and (fsc-instance-p x)
1648        (eq (clos-slots-ref (get-slots x) *sgf-method-class-index*)
1649            +slot-unbound+)))
1650
1651 (defvar *sgf-methods-index*
1652   (!bootstrap-slot-index 'standard-generic-function 'methods))
1653
1654 (defmacro early-gf-methods (gf)
1655   `(clos-slots-ref (get-slots ,gf) *sgf-methods-index*))
1656
1657 (defun safe-generic-function-methods (generic-function)
1658   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
1659       (clos-slots-ref (get-slots generic-function) *sgf-methods-index*)
1660       (generic-function-methods generic-function)))
1661
1662 (defvar *sgf-arg-info-index*
1663   (!bootstrap-slot-index 'standard-generic-function 'arg-info))
1664
1665 (defmacro early-gf-arg-info (gf)
1666   `(clos-slots-ref (get-slots ,gf) *sgf-arg-info-index*))
1667
1668 (defvar *sgf-dfun-state-index*
1669   (!bootstrap-slot-index 'standard-generic-function 'dfun-state))
1670
1671 (defstruct (arg-info
1672             (:conc-name nil)
1673             (:constructor make-arg-info ())
1674             (:copier nil))
1675   (arg-info-lambda-list :no-lambda-list)
1676   arg-info-precedence
1677   arg-info-metatypes
1678   arg-info-number-optional
1679   arg-info-key/rest-p
1680   arg-info-keys   ;nil        no &KEY or &REST allowed
1681                   ;(k1 k2 ..) Each method must accept these &KEY arguments.
1682                   ;T          must have &KEY or &REST
1683
1684   gf-info-simple-accessor-type ; nil, reader, writer, boundp
1685   (gf-precompute-dfun-and-emf-p nil) ; set by set-arg-info
1686
1687   gf-info-static-c-a-m-emf
1688   (gf-info-c-a-m-emf-std-p t)
1689   gf-info-fast-mf-p)
1690
1691 #-sb-fluid (declaim (sb-ext:freeze-type arg-info))
1692
1693 (defun arg-info-valid-p (arg-info)
1694   (not (null (arg-info-number-optional arg-info))))
1695
1696 (defun arg-info-applyp (arg-info)
1697   (or (plusp (arg-info-number-optional arg-info))
1698       (arg-info-key/rest-p arg-info)))
1699
1700 (defun arg-info-number-required (arg-info)
1701   (length (arg-info-metatypes arg-info)))
1702
1703 (defun arg-info-nkeys (arg-info)
1704   (count-if (lambda (x) (neq x t)) (arg-info-metatypes arg-info)))
1705
1706 (defun create-gf-lambda-list (lambda-list)
1707   ;;; Create a gf lambda list from a method lambda list
1708   (loop for x in lambda-list
1709         collect (if (consp x) (list (car x)) x)
1710         if (eq x '&key) do (loop-finish)))
1711
1712 (defun set-arg-info (gf &key new-method (lambda-list nil lambda-list-p)
1713                         argument-precedence-order)
1714   (let* ((arg-info (if (eq *boot-state* 'complete)
1715                        (gf-arg-info gf)
1716                        (early-gf-arg-info gf)))
1717          (methods (if (eq *boot-state* 'complete)
1718                       (generic-function-methods gf)
1719                       (early-gf-methods gf)))
1720          (was-valid-p (integerp (arg-info-number-optional arg-info)))
1721          (first-p (and new-method (null (cdr methods)))))
1722     (when (and (not lambda-list-p) methods)
1723       (setq lambda-list (gf-lambda-list gf)))
1724     (when (or lambda-list-p
1725               (and first-p
1726                    (eq (arg-info-lambda-list arg-info) :no-lambda-list)))
1727       (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1728           (analyze-lambda-list lambda-list)
1729         (when (and methods (not first-p))
1730           (let ((gf-nreq (arg-info-number-required arg-info))
1731                 (gf-nopt (arg-info-number-optional arg-info))
1732                 (gf-key/rest-p (arg-info-key/rest-p arg-info)))
1733             (unless (and (= nreq gf-nreq)
1734                          (= nopt gf-nopt)
1735                          (eq (or keysp restp) gf-key/rest-p))
1736               (error "The lambda-list ~S is incompatible with ~
1737                      existing methods of ~S."
1738                      lambda-list gf))))
1739         (setf (arg-info-lambda-list arg-info)
1740               (if lambda-list-p
1741                   lambda-list
1742                    (create-gf-lambda-list lambda-list)))
1743         (when (or lambda-list-p argument-precedence-order
1744                   (null (arg-info-precedence arg-info)))
1745           (setf (arg-info-precedence arg-info)
1746                 (compute-precedence lambda-list nreq argument-precedence-order)))
1747         (setf (arg-info-metatypes arg-info) (make-list nreq))
1748         (setf (arg-info-number-optional arg-info) nopt)
1749         (setf (arg-info-key/rest-p arg-info) (not (null (or keysp restp))))
1750         (setf (arg-info-keys arg-info)
1751               (if lambda-list-p
1752                   (if allow-other-keys-p t keywords)
1753                   (arg-info-key/rest-p arg-info)))))
1754     (when new-method
1755       (check-method-arg-info gf arg-info new-method))
1756     (set-arg-info1 gf arg-info new-method methods was-valid-p first-p)
1757     arg-info))
1758
1759 (defun check-method-arg-info (gf arg-info method)
1760   (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)
1761       (analyze-lambda-list (if (consp method)
1762                                (early-method-lambda-list method)
1763                                (method-lambda-list method)))
1764     (flet ((lose (string &rest args)
1765              (error 'simple-program-error
1766                     :format-control "~@<attempt to add the method~2I~_~S~I~_~
1767                                      to the generic function~2I~_~S;~I~_~
1768                                      but ~?~:>"
1769                     :format-arguments (list method gf string args)))
1770            (comparison-description (x y)
1771              (if (> x y) "more" "fewer")))
1772       (let ((gf-nreq (arg-info-number-required arg-info))
1773             (gf-nopt (arg-info-number-optional arg-info))
1774             (gf-key/rest-p (arg-info-key/rest-p arg-info))
1775             (gf-keywords (arg-info-keys arg-info)))
1776         (unless (= nreq gf-nreq)
1777           (lose
1778            "the method has ~A required arguments than the generic function."
1779            (comparison-description nreq gf-nreq)))
1780         (unless (= nopt gf-nopt)
1781           (lose
1782            "the method has ~A optional arguments than the generic function."
1783            (comparison-description nopt gf-nopt)))
1784         (unless (eq (or keysp restp) gf-key/rest-p)
1785           (lose
1786            "the method and generic function differ in whether they accept~_~
1787             &REST or &KEY arguments."))
1788         (when (consp gf-keywords)
1789           (unless (or (and restp (not keysp))
1790                       allow-other-keys-p
1791                       (every (lambda (k) (memq k keywords)) gf-keywords))
1792             (lose "the method does not accept each of the &KEY arguments~2I~_~
1793                    ~S."
1794                   gf-keywords)))))))
1795
1796 (defvar *sm-specializers-index*
1797   (!bootstrap-slot-index 'standard-method 'specializers))
1798 (defvar *sm-%function-index*
1799   (!bootstrap-slot-index 'standard-method '%function))
1800 (defvar *sm-qualifiers-index*
1801   (!bootstrap-slot-index 'standard-method 'qualifiers))
1802 (defvar *sm-plist-index*
1803   (!bootstrap-slot-index 'standard-method 'plist))
1804
1805 ;;; FIXME: we don't actually need this; we could test for the exact
1806 ;;; class and deal with it as appropriate.  In fact we probably don't
1807 ;;; need it anyway because we only use this for METHOD-SPECIALIZERS on
1808 ;;; the standard reader method for METHOD-SPECIALIZERS.  Probably.
1809 (dolist (s '(specializers %function plist))
1810   (aver (= (symbol-value (intern (format nil "*SM-~A-INDEX*" s)))
1811            (!bootstrap-slot-index 'standard-reader-method s)
1812            (!bootstrap-slot-index 'standard-writer-method s)
1813            (!bootstrap-slot-index 'standard-boundp-method s))))
1814
1815 (defun safe-method-specializers (method)
1816   (let ((standard-method-classes
1817          (list *the-class-standard-method*
1818                *the-class-standard-reader-method*
1819                *the-class-standard-writer-method*
1820                *the-class-standard-boundp-method*))
1821         (class (class-of method)))
1822     (if (member class standard-method-classes)
1823         (clos-slots-ref (get-slots method) *sm-specializers-index*)
1824         (method-specializers method))))
1825 (defun safe-method-fast-function (method)
1826   (let ((mf (safe-method-function method)))
1827     (and (typep mf '%method-function)
1828          (%method-function-fast-function mf))))
1829 (defun safe-method-function (method)
1830   (let ((standard-method-classes
1831          (list *the-class-standard-method*
1832                *the-class-standard-reader-method*
1833                *the-class-standard-writer-method*
1834                *the-class-standard-boundp-method*))
1835         (class (class-of method)))
1836     (if (member class standard-method-classes)
1837         (clos-slots-ref (get-slots method) *sm-%function-index*)
1838         (method-function method))))
1839 (defun safe-method-qualifiers (method)
1840   (let ((standard-method-classes
1841          (list *the-class-standard-method*
1842                *the-class-standard-reader-method*
1843                *the-class-standard-writer-method*
1844                *the-class-standard-boundp-method*))
1845         (class (class-of method)))
1846     (if (member class standard-method-classes)
1847         (clos-slots-ref (get-slots method) *sm-qualifiers-index*)
1848         (method-qualifiers method))))
1849
1850 (defun set-arg-info1 (gf arg-info new-method methods was-valid-p first-p)
1851   (let* ((existing-p (and methods (cdr methods) new-method))
1852          (nreq (length (arg-info-metatypes arg-info)))
1853          (metatypes (if existing-p
1854                         (arg-info-metatypes arg-info)
1855                         (make-list nreq)))
1856          (type (if existing-p
1857                    (gf-info-simple-accessor-type arg-info)
1858                    nil)))
1859     (when (arg-info-valid-p arg-info)
1860       (dolist (method (if new-method (list new-method) methods))
1861         (let* ((specializers (if (or (eq *boot-state* 'complete)
1862                                      (not (consp method)))
1863                                  (safe-method-specializers method)
1864                                  (early-method-specializers method t)))
1865                (class (if (or (eq *boot-state* 'complete) (not (consp method)))
1866                           (class-of method)
1867                           (early-method-class method)))
1868                (new-type
1869                 (when (and class
1870                            (or (not (eq *boot-state* 'complete))
1871                                (eq (generic-function-method-combination gf)
1872                                    *standard-method-combination*)))
1873                   (cond ((or (eq class *the-class-standard-reader-method*)
1874                              (eq class *the-class-global-reader-method*))
1875                          'reader)
1876                         ((or (eq class *the-class-standard-writer-method*)
1877                              (eq class *the-class-global-writer-method*))
1878                          'writer)
1879                         ((or (eq class *the-class-standard-boundp-method*)
1880                              (eq class *the-class-global-boundp-method*))
1881                          'boundp)))))
1882           (setq metatypes (mapcar #'raise-metatype metatypes specializers))
1883           (setq type (cond ((null type) new-type)
1884                            ((eq type new-type) type)
1885                            (t nil)))))
1886       (setf (arg-info-metatypes arg-info) metatypes)
1887       (setf (gf-info-simple-accessor-type arg-info) type)))
1888   (when (or (not was-valid-p) first-p)
1889     (multiple-value-bind (c-a-m-emf std-p)
1890         (if (early-gf-p gf)
1891             (values t t)
1892             (compute-applicable-methods-emf gf))
1893       (setf (gf-info-static-c-a-m-emf arg-info) c-a-m-emf)
1894       (setf (gf-info-c-a-m-emf-std-p arg-info) std-p)
1895       (unless (gf-info-c-a-m-emf-std-p arg-info)
1896         (setf (gf-info-simple-accessor-type arg-info) t))))
1897   (unless was-valid-p
1898     (let ((name (if (eq *boot-state* 'complete)
1899                     (generic-function-name gf)
1900                     (!early-gf-name gf))))
1901       (setf (gf-precompute-dfun-and-emf-p arg-info)
1902             (cond
1903               ((and (consp name)
1904                     (member (car name)
1905                             *internal-pcl-generalized-fun-name-symbols*))
1906                 nil)
1907               (t (let* ((symbol (fun-name-block-name name))
1908                         (package (symbol-package symbol)))
1909                    (and (or (eq package *pcl-package*)
1910                             (memq package (package-use-list *pcl-package*)))
1911                         ;; FIXME: this test will eventually be
1912                         ;; superseded by the *internal-pcl...* test,
1913                         ;; above.  While we are in a process of
1914                         ;; transition, however, it should probably
1915                         ;; remain.
1916                         (not (find #\Space (symbol-name symbol))))))))))
1917   (setf (gf-info-fast-mf-p arg-info)
1918         (or (not (eq *boot-state* 'complete))
1919             (let* ((method-class (generic-function-method-class gf))
1920                    (methods (compute-applicable-methods
1921                              #'make-method-lambda
1922                              (list gf (class-prototype method-class)
1923                                    '(lambda) nil))))
1924               (and methods (null (cdr methods))
1925                    (let ((specls (method-specializers (car methods))))
1926                      (and (classp (car specls))
1927                           (eq 'standard-generic-function
1928                               (class-name (car specls)))
1929                           (classp (cadr specls))
1930                           (eq 'standard-method
1931                               (class-name (cadr specls)))))))))
1932   arg-info)
1933
1934 ;;; This is the early definition of ENSURE-GENERIC-FUNCTION-USING-CLASS.
1935 ;;;
1936 ;;; The STATIC-SLOTS field of the funcallable instances used as early
1937 ;;; generic functions is used to store the early methods and early
1938 ;;; discriminator code for the early generic function. The static
1939 ;;; slots field of the fins contains a list whose:
1940 ;;;    CAR    -   a list of the early methods on this early gf
1941 ;;;    CADR   -   the early discriminator code for this method
1942 (defun ensure-generic-function-using-class (existing spec &rest keys
1943                                             &key (lambda-list nil
1944                                                               lambda-list-p)
1945                                             argument-precedence-order
1946                                             source-location
1947                                             &allow-other-keys)
1948   (declare (ignore keys))
1949   (cond ((and existing (early-gf-p existing))
1950          (when lambda-list-p
1951            (set-arg-info existing :lambda-list lambda-list))
1952          existing)
1953         ((assoc spec *!generic-function-fixups* :test #'equal)
1954          (if existing
1955              (make-early-gf spec lambda-list lambda-list-p existing
1956                             argument-precedence-order source-location)
1957              (error "The function ~S is not already defined." spec)))
1958         (existing
1959          (error "~S should be on the list ~S."
1960                 spec
1961                 '*!generic-function-fixups*))
1962         (t
1963          (pushnew spec *!early-generic-functions* :test #'equal)
1964          (make-early-gf spec lambda-list lambda-list-p nil
1965                         argument-precedence-order source-location))))
1966
1967 (defun make-early-gf (spec &optional lambda-list lambda-list-p
1968                       function argument-precedence-order source-location)
1969   (let ((fin (allocate-standard-funcallable-instance
1970               *sgf-wrapper* *sgf-slots-init*)))
1971     (set-funcallable-instance-function
1972      fin
1973      (or function
1974          (if (eq spec 'print-object)
1975              #'(lambda (instance stream)
1976                  (print-unreadable-object (instance stream :identity t)
1977                    (format stream "std-instance")))
1978              #'(lambda (&rest args)
1979                  (declare (ignore args))
1980                  (error "The function of the funcallable-instance ~S~
1981                          has not been set." fin)))))
1982     (setf (gdefinition spec) fin)
1983     (!bootstrap-set-slot 'standard-generic-function fin 'name spec)
1984     (!bootstrap-set-slot 'standard-generic-function
1985                          fin
1986                          'source
1987                          source-location)
1988     (set-fun-name fin spec)
1989     (let ((arg-info (make-arg-info)))
1990       (setf (early-gf-arg-info fin) arg-info)
1991       (when lambda-list-p
1992         (proclaim (defgeneric-declaration spec lambda-list))
1993         (if argument-precedence-order
1994             (set-arg-info fin
1995                           :lambda-list lambda-list
1996                           :argument-precedence-order argument-precedence-order)
1997             (set-arg-info fin :lambda-list lambda-list))))
1998     fin))
1999
2000 (defun safe-gf-dfun-state (generic-function)
2001   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2002       (clos-slots-ref (get-slots generic-function) *sgf-dfun-state-index*)
2003       (gf-dfun-state generic-function)))
2004 (defun (setf safe-gf-dfun-state) (new-value generic-function)
2005   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2006       (setf (clos-slots-ref (get-slots generic-function)
2007                             *sgf-dfun-state-index*)
2008             new-value)
2009       (setf (gf-dfun-state generic-function) new-value)))
2010
2011 (defun set-dfun (gf &optional dfun cache info)
2012   (let ((new-state (if (and dfun (or cache info))
2013                        (list* dfun cache info)
2014                        dfun)))
2015     (if (eq *boot-state* 'complete)
2016         (setf (safe-gf-dfun-state gf) new-state)
2017         (setf (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*)
2018               new-state)))
2019   dfun)
2020
2021 (defun gf-dfun-cache (gf)
2022   (let ((state (if (eq *boot-state* 'complete)
2023                    (safe-gf-dfun-state gf)
2024                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
2025     (typecase state
2026       (function nil)
2027       (cons (cadr state)))))
2028
2029 (defun gf-dfun-info (gf)
2030   (let ((state (if (eq *boot-state* 'complete)
2031                    (safe-gf-dfun-state gf)
2032                    (clos-slots-ref (get-slots gf) *sgf-dfun-state-index*))))
2033     (typecase state
2034       (function nil)
2035       (cons (cddr state)))))
2036
2037 (defvar *sgf-name-index*
2038   (!bootstrap-slot-index 'standard-generic-function 'name))
2039
2040 (defun !early-gf-name (gf)
2041   (clos-slots-ref (get-slots gf) *sgf-name-index*))
2042
2043 (defun gf-lambda-list (gf)
2044   (let ((arg-info (if (eq *boot-state* 'complete)
2045                       (gf-arg-info gf)
2046                       (early-gf-arg-info gf))))
2047     (if (eq :no-lambda-list (arg-info-lambda-list arg-info))
2048         (let ((methods (if (eq *boot-state* 'complete)
2049                            (generic-function-methods gf)
2050                            (early-gf-methods gf))))
2051           (if (null methods)
2052               (progn
2053                 (warn "no way to determine the lambda list for ~S" gf)
2054                 nil)
2055               (let* ((method (car (last methods)))
2056                      (ll (if (consp method)
2057                              (early-method-lambda-list method)
2058                              (method-lambda-list method))))
2059                 (create-gf-lambda-list ll))))
2060         (arg-info-lambda-list arg-info))))
2061
2062 (defmacro real-ensure-gf-internal (gf-class all-keys env)
2063   `(progn
2064      (cond ((symbolp ,gf-class)
2065             (setq ,gf-class (find-class ,gf-class t ,env)))
2066            ((classp ,gf-class))
2067            (t
2068             (error "The :GENERIC-FUNCTION-CLASS argument (~S) was neither a~%~
2069                     class nor a symbol that names a class."
2070                    ,gf-class)))
2071      (unless (class-finalized-p ,gf-class)
2072        (if (class-has-a-forward-referenced-superclass-p ,gf-class)
2073            ;; FIXME: reference MOP documentation -- this is an
2074            ;; additional requirement on our users
2075            (error "The generic function class ~S is not finalizeable" ,gf-class)
2076            (finalize-inheritance ,gf-class)))
2077      (remf ,all-keys :generic-function-class)
2078      (remf ,all-keys :environment)
2079      (let ((combin (getf ,all-keys :method-combination '.shes-not-there.)))
2080        (unless (eq combin '.shes-not-there.)
2081          (setf (getf ,all-keys :method-combination)
2082                (find-method-combination (class-prototype ,gf-class)
2083                                         (car combin)
2084                                         (cdr combin)))))
2085     (let ((method-class (getf ,all-keys :method-class '.shes-not-there.)))
2086       (unless (eq method-class '.shes-not-there.)
2087         (setf (getf ,all-keys :method-class)
2088               (cond ((classp method-class)
2089                      method-class)
2090                     (t (find-class method-class t ,env))))))))
2091
2092 (defun real-ensure-gf-using-class--generic-function
2093        (existing
2094         fun-name
2095         &rest all-keys
2096         &key environment (lambda-list nil lambda-list-p)
2097         (generic-function-class 'standard-generic-function)
2098         &allow-other-keys)
2099   (real-ensure-gf-internal generic-function-class all-keys environment)
2100   ;; KLUDGE: the above macro does SETQ on GENERIC-FUNCTION-CLASS,
2101   ;; which is what makes the next line work
2102   (unless (eq (class-of existing) generic-function-class)
2103     (change-class existing generic-function-class))
2104   (prog1
2105       (apply #'reinitialize-instance existing all-keys)
2106     (when lambda-list-p
2107       (proclaim (defgeneric-declaration fun-name lambda-list)))))
2108
2109 (defun real-ensure-gf-using-class--null
2110        (existing
2111         fun-name
2112         &rest all-keys
2113         &key environment (lambda-list nil lambda-list-p)
2114              (generic-function-class 'standard-generic-function)
2115         &allow-other-keys)
2116   (declare (ignore existing))
2117   (real-ensure-gf-internal generic-function-class all-keys environment)
2118   (prog1
2119       (setf (gdefinition fun-name)
2120             (apply #'make-instance generic-function-class
2121                    :name fun-name all-keys))
2122     (when lambda-list-p
2123       (proclaim (defgeneric-declaration fun-name lambda-list)))))
2124 \f
2125 (defun safe-gf-arg-info (generic-function)
2126   (if (eq (class-of generic-function) *the-class-standard-generic-function*)
2127       (clos-slots-ref (fsc-instance-slots generic-function)
2128                       *sgf-arg-info-index*)
2129       (gf-arg-info generic-function)))
2130
2131 ;;; FIXME: this function took on a slightly greater role than it
2132 ;;; previously had around 2005-11-02, when CSR fixed the bug whereby
2133 ;;; having more than one subclass of standard-generic-function caused
2134 ;;; the whole system to die horribly through a metacircle in
2135 ;;; GF-ARG-INFO.  The fix is to be slightly more disciplined about
2136 ;;; calling accessor methods -- we call GET-GENERIC-FUN-INFO when
2137 ;;; computing discriminating functions, so we need to be careful about
2138 ;;; having a base case for the recursion, and we provide that with the
2139 ;;; STANDARD-GENERIC-FUNCTION case below.  However, we are not (yet)
2140 ;;; as disciplined as CLISP's CLOS/MOP, and it would be nice to get to
2141 ;;; that stage, where all potentially dangerous cases are enumerated
2142 ;;; and stopped.  -- CSR, 2005-11-02.
2143 (defun get-generic-fun-info (gf)
2144   ;; values   nreq applyp metatypes nkeys arg-info
2145   (multiple-value-bind (applyp metatypes arg-info)
2146       (let* ((arg-info (if (early-gf-p gf)
2147                            (early-gf-arg-info gf)
2148                            (safe-gf-arg-info gf)))
2149              (metatypes (arg-info-metatypes arg-info)))
2150         (values (arg-info-applyp arg-info)
2151                 metatypes
2152                 arg-info))
2153     (values (length metatypes) applyp metatypes
2154             (count-if (lambda (x) (neq x t)) metatypes)
2155             arg-info)))
2156
2157 (defun early-make-a-method (class qualifiers arglist specializers initargs doc
2158                             &key slot-name object-class method-class-function)
2159   (let ((parsed ())
2160         (unparsed ()))
2161     ;; Figure out whether we got class objects or class names as the
2162     ;; specializers and set parsed and unparsed appropriately. If we
2163     ;; got class objects, then we can compute unparsed, but if we got
2164     ;; class names we don't try to compute parsed.
2165     ;;
2166     ;; Note that the use of not symbolp in this call to every should be
2167     ;; read as 'classp' we can't use classp itself because it doesn't
2168     ;; exist yet.
2169     (if (every (lambda (s) (not (symbolp s))) specializers)
2170         (setq parsed specializers
2171               unparsed (mapcar (lambda (s)
2172                                  (if (eq s t) t (class-name s)))
2173                                specializers))
2174         (setq unparsed specializers
2175               parsed ()))
2176     (let ((result
2177            (list :early-method
2178
2179                  (getf initargs :function)
2180                  (let ((mf (getf initargs :function)))
2181                    (aver mf)
2182                    (and (typep mf '%method-function)
2183                         (%method-function-fast-function mf)))
2184
2185                  ;; the parsed specializers. This is used by
2186                  ;; EARLY-METHOD-SPECIALIZERS to cache the parse.
2187                  ;; Note that this only comes into play when there is
2188                  ;; more than one early method on an early gf.
2189                  parsed
2190
2191                  ;; A list to which REAL-MAKE-A-METHOD can be applied
2192                  ;; to make a real method corresponding to this early
2193                  ;; one.
2194                  (append
2195                   (list class qualifiers arglist unparsed
2196                         initargs doc)
2197                   (when slot-name
2198                     (list :slot-name slot-name :object-class object-class
2199                           :method-class-function method-class-function))))))
2200       (initialize-method-function initargs result)
2201       result)))
2202
2203 (defun real-make-a-method
2204        (class qualifiers lambda-list specializers initargs doc
2205         &rest args &key slot-name object-class method-class-function)
2206   (setq specializers (parse-specializers specializers))
2207   (if method-class-function
2208       (let* ((object-class (if (classp object-class) object-class
2209                                (find-class object-class)))
2210              (slots (class-direct-slots object-class))
2211              (slot-definition (find slot-name slots
2212                                     :key #'slot-definition-name)))
2213         (aver slot-name)
2214         (aver slot-definition)
2215         (let ((initargs (list* :qualifiers qualifiers :lambda-list lambda-list
2216                                :specializers specializers :documentation doc
2217                                :slot-definition slot-definition
2218                                :slot-name slot-name initargs)))
2219           (apply #'make-instance
2220                  (apply method-class-function object-class slot-definition
2221                         initargs)
2222                  initargs)))
2223       (apply #'make-instance class :qualifiers qualifiers
2224              :lambda-list lambda-list :specializers specializers
2225              :documentation doc (append args initargs))))
2226
2227 (defun early-method-function (early-method)
2228   (values (cadr early-method) (caddr early-method)))
2229
2230 (defun early-method-class (early-method)
2231   (find-class (car (fifth early-method))))
2232
2233 (defun early-method-standard-accessor-p (early-method)
2234   (let ((class (first (fifth early-method))))
2235     (or (eq class 'standard-reader-method)
2236         (eq class 'standard-writer-method)
2237         (eq class 'standard-boundp-method))))
2238
2239 (defun early-method-standard-accessor-slot-name (early-method)
2240   (eighth (fifth early-method)))
2241
2242 ;;; Fetch the specializers of an early method. This is basically just
2243 ;;; a simple accessor except that when the second argument is t, this
2244 ;;; converts the specializers from symbols into class objects. The
2245 ;;; class objects are cached in the early method, this makes
2246 ;;; bootstrapping faster because the class objects only have to be
2247 ;;; computed once.
2248 ;;;
2249 ;;; NOTE:
2250 ;;;  The second argument should only be passed as T by
2251 ;;;  early-lookup-method. This is to implement the rule that only when
2252 ;;;  there is more than one early method on a generic function is the
2253 ;;;  conversion from class names to class objects done. This
2254 ;;;  corresponds to the fact that we are only allowed to have one
2255 ;;;  method on any generic function up until the time classes exist.
2256 (defun early-method-specializers (early-method &optional objectsp)
2257   (if (and (listp early-method)
2258            (eq (car early-method) :early-method))
2259       (cond ((eq objectsp t)
2260              (or (fourth early-method)
2261                  (setf (fourth early-method)
2262                        (mapcar #'find-class (cadddr (fifth early-method))))))
2263             (t
2264              (fourth (fifth early-method))))
2265       (error "~S is not an early-method." early-method)))
2266
2267 (defun early-method-qualifiers (early-method)
2268   (second (fifth early-method)))
2269
2270 (defun early-method-lambda-list (early-method)
2271   (third (fifth early-method)))
2272
2273 (defun early-method-initargs (early-method)
2274   (fifth (fifth early-method)))
2275
2276 (defun (setf early-method-initargs) (new-value early-method)
2277   (setf (fifth (fifth early-method)) new-value))
2278
2279 (defun early-add-named-method (generic-function-name
2280                                qualifiers
2281                                specializers
2282                                arglist
2283                                &rest initargs)
2284   (let* (;; we don't need to deal with the :generic-function-class
2285          ;; argument here because the default,
2286          ;; STANDARD-GENERIC-FUNCTION, is right for all early generic
2287          ;; functions.  (See REAL-ADD-NAMED-METHOD)
2288          (gf (ensure-generic-function generic-function-name))
2289          (existing
2290            (dolist (m (early-gf-methods gf))
2291              (when (and (equal (early-method-specializers m) specializers)
2292                         (equal (early-method-qualifiers m) qualifiers))
2293                (return m))))
2294          (new (make-a-method 'standard-method
2295                              qualifiers
2296                              arglist
2297                              specializers
2298                              initargs
2299                              ())))
2300     (when existing (remove-method gf existing))
2301     (add-method gf new)))
2302
2303 ;;; This is the early version of ADD-METHOD. Later this will become a
2304 ;;; generic function. See !FIX-EARLY-GENERIC-FUNCTIONS which has
2305 ;;; special knowledge about ADD-METHOD.
2306 (defun add-method (generic-function method)
2307   (when (not (fsc-instance-p generic-function))
2308     (error "Early ADD-METHOD didn't get a funcallable instance."))
2309   (when (not (and (listp method) (eq (car method) :early-method)))
2310     (error "Early ADD-METHOD didn't get an early method."))
2311   (push method (early-gf-methods generic-function))
2312   (set-arg-info generic-function :new-method method)
2313   (unless (assoc (!early-gf-name generic-function)
2314                  *!generic-function-fixups*
2315                  :test #'equal)
2316     (update-dfun generic-function)))
2317
2318 ;;; This is the early version of REMOVE-METHOD. See comments on
2319 ;;; the early version of ADD-METHOD.
2320 (defun remove-method (generic-function method)
2321   (when (not (fsc-instance-p generic-function))
2322     (error "An early remove-method didn't get a funcallable instance."))
2323   (when (not (and (listp method) (eq (car method) :early-method)))
2324     (error "An early remove-method didn't get an early method."))
2325   (setf (early-gf-methods generic-function)
2326         (remove method (early-gf-methods generic-function)))
2327   (set-arg-info generic-function)
2328   (unless (assoc (!early-gf-name generic-function)
2329                  *!generic-function-fixups*
2330                  :test #'equal)
2331     (update-dfun generic-function)))
2332
2333 ;;; This is the early version of GET-METHOD. See comments on the early
2334 ;;; version of ADD-METHOD.
2335 (defun get-method (generic-function qualifiers specializers
2336                                     &optional (errorp t))
2337   (if (early-gf-p generic-function)
2338       (or (dolist (m (early-gf-methods generic-function))
2339             (when (and (or (equal (early-method-specializers m nil)
2340                                   specializers)
2341                            (equal (early-method-specializers m t)
2342                                   specializers))
2343                        (equal (early-method-qualifiers m) qualifiers))
2344               (return m)))
2345           (if errorp
2346               (error "can't get early method")
2347               nil))
2348       (real-get-method generic-function qualifiers specializers errorp)))
2349
2350 (defun !fix-early-generic-functions ()
2351   (let ((accessors nil))
2352     ;; Rearrange *!EARLY-GENERIC-FUNCTIONS* to speed up
2353     ;; FIX-EARLY-GENERIC-FUNCTIONS.
2354     (dolist (early-gf-spec *!early-generic-functions*)
2355       (when (every #'early-method-standard-accessor-p
2356                    (early-gf-methods (gdefinition early-gf-spec)))
2357         (push early-gf-spec accessors)))
2358     (dolist (spec (nconc accessors
2359                          '(accessor-method-slot-name
2360                            generic-function-methods
2361                            method-specializers
2362                            specializerp
2363                            specializer-type
2364                            specializer-class
2365                            slot-definition-location
2366                            slot-definition-name
2367                            class-slots
2368                            gf-arg-info
2369                            class-precedence-list
2370                            slot-boundp-using-class
2371                            (setf slot-value-using-class)
2372                            slot-value-using-class
2373                            structure-class-p
2374                            standard-class-p
2375                            funcallable-standard-class-p
2376                            specializerp)))
2377       (/show spec)
2378       (setq *!early-generic-functions*
2379             (cons spec
2380                   (delete spec *!early-generic-functions* :test #'equal))))
2381
2382     (dolist (early-gf-spec *!early-generic-functions*)
2383       (/show early-gf-spec)
2384       (let* ((gf (gdefinition early-gf-spec))
2385              (methods (mapcar (lambda (early-method)
2386                                 (let ((args (copy-list (fifth
2387                                                         early-method))))
2388                                   (setf (fourth args)
2389                                         (early-method-specializers
2390                                          early-method t))
2391                                   (apply #'real-make-a-method args)))
2392                               (early-gf-methods gf))))
2393         (setf (generic-function-method-class gf) *the-class-standard-method*)
2394         (setf (generic-function-method-combination gf)
2395               *standard-method-combination*)
2396         (set-methods gf methods)))
2397
2398     (dolist (fn *!early-functions*)
2399       (/show fn)
2400       (setf (gdefinition (car fn)) (fdefinition (caddr fn))))
2401
2402     (dolist (fixup *!generic-function-fixups*)
2403       (/show fixup)
2404       (let* ((fspec (car fixup))
2405              (gf (gdefinition fspec))
2406              (methods (mapcar (lambda (method)
2407                                 (let* ((lambda-list (first method))
2408                                        (specializers (second method))
2409                                        (method-fn-name (third method))
2410                                        (fn-name (or method-fn-name fspec))
2411                                        (fn (fdefinition fn-name))
2412                                        (initargs
2413                                         (list :function
2414                                               (set-fun-name
2415                                                (lambda (args next-methods)
2416                                                  (declare (ignore
2417                                                            next-methods))
2418                                                  (apply fn args))
2419                                                `(call ,fn-name)))))
2420                                   (declare (type function fn))
2421                                   (make-a-method 'standard-method
2422                                                  ()
2423                                                  lambda-list
2424                                                  specializers
2425                                                  initargs
2426                                                  nil)))
2427                               (cdr fixup))))
2428         (setf (generic-function-method-class gf) *the-class-standard-method*)
2429         (setf (generic-function-method-combination gf)
2430               *standard-method-combination*)
2431         (set-methods gf methods))))
2432   (/show "leaving !FIX-EARLY-GENERIC-FUNCTIONS"))
2433 \f
2434 ;;; PARSE-DEFMETHOD is used by DEFMETHOD to parse the &REST argument
2435 ;;; into the 'real' arguments. This is where the syntax of DEFMETHOD
2436 ;;; is really implemented.
2437 (defun parse-defmethod (cdr-of-form)
2438   (declare (list cdr-of-form))
2439   (let ((name (pop cdr-of-form))
2440         (qualifiers ())
2441         (spec-ll ()))
2442     (loop (if (and (car cdr-of-form) (atom (car cdr-of-form)))
2443               (push (pop cdr-of-form) qualifiers)
2444               (return (setq qualifiers (nreverse qualifiers)))))
2445     (setq spec-ll (pop cdr-of-form))
2446     (values name qualifiers spec-ll cdr-of-form)))
2447
2448 (defun parse-specializers (specializers)
2449   (declare (list specializers))
2450   (flet ((parse (spec)
2451            (let ((result (specializer-from-type spec)))
2452              (if (specializerp result)
2453                  result
2454                  (if (symbolp spec)
2455                      (error "~S was used as a specializer,~%~
2456                              but is not the name of a class."
2457                             spec)
2458                      (error "~S is not a legal specializer." spec))))))
2459     (mapcar #'parse specializers)))
2460
2461 (defun unparse-specializers (specializers-or-method)
2462   (if (listp specializers-or-method)
2463       (flet ((unparse (spec)
2464                (if (specializerp spec)
2465                    (let ((type (specializer-type spec)))
2466                      (if (and (consp type)
2467                               (eq (car type) 'class))
2468                          (let* ((class (cadr type))
2469                                 (class-name (class-name class)))
2470                            (if (eq class (find-class class-name nil))
2471                                class-name
2472                                type))
2473                          type))
2474                    (error "~S is not a legal specializer." spec))))
2475         (mapcar #'unparse specializers-or-method))
2476       (unparse-specializers (method-specializers specializers-or-method))))
2477
2478 (defun parse-method-or-spec (spec &optional (errorp t))
2479   (let (gf method name temp)
2480     (if (method-p spec)
2481         (setq method spec
2482               gf (method-generic-function method)
2483               temp (and gf (generic-function-name gf))
2484               name (if temp
2485                        (make-method-spec temp
2486                                          (method-qualifiers method)
2487                                          (unparse-specializers
2488                                           (method-specializers method)))
2489                        (make-symbol (format nil "~S" method))))
2490         (multiple-value-bind (gf-spec quals specls)
2491             (parse-defmethod spec)
2492           (and (setq gf (and (or errorp (fboundp gf-spec))
2493                              (gdefinition gf-spec)))
2494                (let ((nreq (compute-discriminating-function-arglist-info gf)))
2495                  (setq specls (append (parse-specializers specls)
2496                                       (make-list (- nreq (length specls))
2497                                                  :initial-element
2498                                                  *the-class-t*)))
2499                  (and
2500                    (setq method (get-method gf quals specls errorp))
2501                    (setq name
2502                          (make-method-spec
2503                           gf-spec quals (unparse-specializers specls))))))))
2504     (values gf method name)))
2505 \f
2506 (defun extract-parameters (specialized-lambda-list)
2507   (multiple-value-bind (parameters ignore1 ignore2)
2508       (parse-specialized-lambda-list specialized-lambda-list)
2509     (declare (ignore ignore1 ignore2))
2510     parameters))
2511
2512 (defun extract-lambda-list (specialized-lambda-list)
2513   (multiple-value-bind (ignore1 lambda-list ignore2)
2514       (parse-specialized-lambda-list specialized-lambda-list)
2515     (declare (ignore ignore1 ignore2))
2516     lambda-list))
2517
2518 (defun extract-specializer-names (specialized-lambda-list)
2519   (multiple-value-bind (ignore1 ignore2 specializers)
2520       (parse-specialized-lambda-list specialized-lambda-list)
2521     (declare (ignore ignore1 ignore2))
2522     specializers))
2523
2524 (defun extract-required-parameters (specialized-lambda-list)
2525   (multiple-value-bind (ignore1 ignore2 ignore3 required-parameters)
2526       (parse-specialized-lambda-list specialized-lambda-list)
2527     (declare (ignore ignore1 ignore2 ignore3))
2528     required-parameters))
2529
2530 (define-condition specialized-lambda-list-error
2531     (reference-condition simple-program-error)
2532   ()
2533   (:default-initargs :references (list '(:ansi-cl :section (3 4 3)))))
2534
2535 (defun parse-specialized-lambda-list
2536     (arglist
2537      &optional supplied-keywords (allowed-keywords '(&optional &rest &key &aux))
2538      &aux (specialized-lambda-list-keywords
2539            '(&optional &rest &key &allow-other-keys &aux)))
2540   (let ((arg (car arglist)))
2541     (cond ((null arglist) (values nil nil nil nil))
2542           ((eq arg '&aux)
2543            (values nil arglist nil nil))
2544           ((memq arg lambda-list-keywords)
2545            ;; non-standard lambda-list-keywords are errors.
2546            (unless (memq arg specialized-lambda-list-keywords)
2547              (error 'specialized-lambda-list-error
2548                     :format-control "unknown specialized-lambda-list ~
2549                                      keyword ~S~%"
2550                     :format-arguments (list arg)))
2551            ;; no multiple &rest x &rest bla specifying
2552            (when (memq arg supplied-keywords)
2553              (error 'specialized-lambda-list-error
2554                     :format-control "multiple occurrence of ~
2555                                      specialized-lambda-list keyword ~S~%"
2556                     :format-arguments (list arg)))
2557            ;; And no placing &key in front of &optional, either.
2558            (unless (memq arg allowed-keywords)
2559              (error 'specialized-lambda-list-error
2560                     :format-control "misplaced specialized-lambda-list ~
2561                                      keyword ~S~%"
2562                     :format-arguments (list arg)))
2563            ;; When we are at a lambda-list keyword, the parameters
2564            ;; don't include the lambda-list keyword; the lambda-list
2565            ;; does include the lambda-list keyword; and no
2566            ;; specializers are allowed to follow the lambda-list
2567            ;; keywords (at least for now).
2568            (multiple-value-bind (parameters lambda-list)
2569                (parse-specialized-lambda-list (cdr arglist)
2570                                               (cons arg supplied-keywords)
2571                                               (if (eq arg '&key)
2572                                                   (cons '&allow-other-keys
2573                                                         (cdr (member arg allowed-keywords)))
2574                                                 (cdr (member arg allowed-keywords))))
2575              (when (and (eq arg '&rest)
2576                         (or (null lambda-list)
2577                             (memq (car lambda-list)
2578                                   specialized-lambda-list-keywords)
2579                             (not (or (null (cadr lambda-list))
2580                                      (memq (cadr lambda-list)
2581                                            specialized-lambda-list-keywords)))))
2582                (error 'specialized-lambda-list-error
2583                       :format-control
2584                       "in a specialized-lambda-list, excactly one ~
2585                        variable must follow &REST.~%"
2586                       :format-arguments nil))
2587              (values parameters
2588                      (cons arg lambda-list)
2589                      ()
2590                      ())))
2591           (supplied-keywords
2592            ;; After a lambda-list keyword there can be no specializers.
2593            (multiple-value-bind (parameters lambda-list)
2594                (parse-specialized-lambda-list (cdr arglist)
2595                                               supplied-keywords
2596                                               allowed-keywords)
2597              (values (cons (if (listp arg) (car arg) arg) parameters)
2598                      (cons arg lambda-list)
2599                      ()
2600                      ())))
2601           (t
2602            (multiple-value-bind (parameters lambda-list specializers required)
2603                (parse-specialized-lambda-list (cdr arglist))
2604              (values (cons (if (listp arg) (car arg) arg) parameters)
2605                      (cons (if (listp arg) (car arg) arg) lambda-list)
2606                      (cons (if (listp arg) (cadr arg) t) specializers)
2607                      (cons (if (listp arg) (car arg) arg) required)))))))
2608 \f
2609 (setq *boot-state* 'early)
2610 \f
2611 ;;; FIXME: In here there was a #-CMU definition of SYMBOL-MACROLET
2612 ;;; which used %WALKER stuff. That suggests to me that maybe the code
2613 ;;; walker stuff was only used for implementing stuff like that; maybe
2614 ;;; it's not needed any more? Hunt down what it was used for and see.
2615
2616 (defmacro with-slots (slots instance &body body)
2617   (let ((in (gensym)))
2618     `(let ((,in ,instance))
2619        (declare (ignorable ,in))
2620        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2621                              (third instance)
2622                              instance)))
2623            (and (symbolp instance)
2624                 `((declare (%variable-rebinding ,in ,instance)))))
2625        ,in
2626        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2627                                    (let ((var-name
2628                                           (if (symbolp slot-entry)
2629                                               slot-entry
2630                                               (car slot-entry)))
2631                                          (slot-name
2632                                           (if (symbolp slot-entry)
2633                                               slot-entry
2634                                               (cadr slot-entry))))
2635                                      `(,var-name
2636                                        (slot-value ,in ',slot-name))))
2637                                  slots)
2638                         ,@body))))
2639
2640 (defmacro with-accessors (slots instance &body body)
2641   (let ((in (gensym)))
2642     `(let ((,in ,instance))
2643        (declare (ignorable ,in))
2644        ,@(let ((instance (if (and (consp instance) (eq (car instance) 'the))
2645                              (third instance)
2646                              instance)))
2647            (and (symbolp instance)
2648                 `((declare (%variable-rebinding ,in ,instance)))))
2649        ,in
2650        (symbol-macrolet ,(mapcar (lambda (slot-entry)
2651                                    (let ((var-name (car slot-entry))
2652                                          (accessor-name (cadr slot-entry)))
2653                                      `(,var-name (,accessor-name ,in))))
2654                                  slots)
2655           ,@body))))