X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fpcl%2Fmethods.lisp;h=eeb37f926c46c958b4de928b04199d63ba459cfb;hb=46d8e06740236e41db254d95c6bdc662039d32f6;hp=9b8487f43174002777914260f19b53123bd3b0c9;hpb=1ffd970d36b42c9d3448d412eb9bd91c55914643;p=sbcl.git

diff --git a/src/pcl/methods.lisp b/src/pcl/methods.lisp
index 9b8487f..eeb37f9 100644
--- a/src/pcl/methods.lisp
+++ b/src/pcl/methods.lisp
@@ -23,29 +23,13 @@
 
 (in-package "SB-PCL")
 
-
 ;;; methods
 ;;;
 ;;; Methods themselves are simple inanimate objects. Most properties of
 ;;; methods are immutable, methods cannot be reinitialized. The following
 ;;; properties of methods can be changed:
 ;;;   METHOD-GENERIC-FUNCTION
-;;;   METHOD-FUNCTION       ??
-
-(defmethod method-function ((method standard-method))
-  (or (slot-value method 'function)
-      (let ((fmf (slot-value method 'fast-function)))
-        (unless fmf ; The :BEFORE SHARED-INITIALIZE method prevents this.
-          (error "~S doesn't seem to have a METHOD-FUNCTION." method))
-        (setf (slot-value method 'function)
-              (method-function-from-fast-function fmf)))))
-
-(defmethod accessor-method-class ((method standard-accessor-method))
-  (car (slot-value method 'specializers)))
-
-(defmethod accessor-method-class ((method standard-writer-method))
-  (cadr (slot-value method 'specializers)))
-
+
 ;;; initialization
 ;;;
 ;;; Error checking is done in before methods. Because of the simplicity of
@@ -54,7 +38,7 @@
 ;;; Methods are not reinitializable.
 
 (define-condition metaobject-initialization-violation
-    (reference-condition simple-condition)
+    (reference-condition simple-error)
   ())
 
 (macrolet ((def (name args control)
@@ -63,7 +47,7 @@
                  (error 'metaobject-initialization-violation
                   :format-control ,(format nil "~@<~A~@:>" control)
                   :format-arguments (list ',name)
-                  :references (list '(:amop :initialization "Method"))))))
+                  :references (list '(:amop :initialization method))))))
   (def reinitialize-instance ((method method) &rest initargs)
     "Method objects cannot be redefined by ~S.")
   (def change-class ((method method) new &rest initargs)
@@ -78,128 +62,100 @@
   (def update-instance-for-different-class ((old method) new &rest initargs)
     "No behaviour specified for ~S on method objects."))
 
-(defmethod legal-documentation-p ((object standard-method) x)
-  (if (or (null x) (stringp x))
-      t
-      "a string or NULL"))
-
-(defmethod legal-lambda-list-p ((object standard-method) x)
-  (declare (ignore x))
-  t)
+(define-condition invalid-method-initarg (simple-program-error)
+  ((method :initarg :method :reader invalid-method-initarg-method))
+  (:report
+   (lambda (c s)
+     (format s "~@<In initialization of ~S:~2I~_~?~@:>"
+             (invalid-method-initarg-method c)
+             (simple-condition-format-control c)
+             (simple-condition-format-arguments c)))))
+
+(defun invalid-method-initarg (method format-control &rest args)
+  (error 'invalid-method-initarg :method method
+         :format-control format-control :format-arguments args))
+
+(defun check-documentation (method doc)
+  (unless (or (null doc) (stringp doc))
+    (invalid-method-initarg method "~@<~S of ~S is neither ~S nor a ~S.~@:>"
+                            :documentation doc 'null 'string)))
+(defun check-lambda-list (method ll)
+  nil)
 
-(defmethod legal-method-function-p ((object standard-method) x)
-  (if (functionp x)
-      t
-      "a function"))
+(defun check-method-function (method fun)
+  (unless (functionp fun)
+    (invalid-method-initarg method "~@<~S of ~S is not a ~S.~@:>"
+                            :function fun 'function)))
 
-(defmethod legal-qualifiers-p ((object standard-method) x)
+(defun check-qualifiers (method qualifiers)
   (flet ((improper-list ()
-           (return-from legal-qualifiers-p "Is not a proper list.")))
-    (dolist-carefully (q x improper-list)
-      (let ((ok (legal-qualifier-p object q)))
-        (unless (eq ok t)
-          (return-from legal-qualifiers-p
-            (format nil "Contains ~S which ~A" q ok)))))
-    t))
-
-(defmethod legal-qualifier-p ((object standard-method) x)
-  (if (and x (atom x))
-      t
-      "is not a non-null atom"))
-
-(defmethod legal-slot-name-p ((object standard-method) x)
-  (cond ((not (symbolp x)) "is not a symbol")
-        (t t)))
-
-(defmethod legal-specializers-p ((object standard-method) x)
+           (invalid-method-initarg method
+                                   "~@<~S of ~S is an improper list.~@:>"
+                                   :qualifiers qualifiers)))
+    (dolist-carefully (q qualifiers improper-list)
+      (unless (and q (atom q))
+        (invalid-method-initarg method
+                                "~@<~S, in ~S ~S, is not a non-~S atom.~@:>"
+                                q :qualifiers qualifiers 'null)))))
+
+(defun check-slot-name (method name)
+  (unless (symbolp name)
+    (invalid-method-initarg "~@<~S of ~S is not a ~S.~@:>"
+                            :slot-name name 'symbol)))
+
+(defun check-specializers (method specializers)
   (flet ((improper-list ()
-           (return-from legal-specializers-p "Is not a proper list.")))
-    (dolist-carefully (s x improper-list)
-      (let ((ok (legal-specializer-p object s)))
-        (unless (eq ok t)
-          (return-from legal-specializers-p
-            (format nil "Contains ~S which ~A" s ok)))))
-    t))
-
-(defvar *allow-experimental-specializers-p* nil)
-
-(defmethod legal-specializer-p ((object standard-method) x)
-  (if (if *allow-experimental-specializers-p*
-          (specializerp x)
-          (or (classp x)
-              (eql-specializer-p x)))
-      t
-      "is neither a class object nor an EQL specializer"))
-
-(defmethod shared-initialize :before ((method standard-method)
-                                      slot-names
-                                      &key qualifiers
-                                           lambda-list
-                                           specializers
-                                           function
-                                           fast-function
-                                           documentation)
+           (invalid-method-initarg method
+                                   "~@<~S of ~S is an improper list.~@:>"
+                                   :specializers specializers)))
+    (dolist-carefully (s specializers improper-list)
+      (unless (specializerp s)
+        (invalid-method-initarg method
+                                "~@<~S, in ~S ~S, is not a ~S.~@:>"
+                                s :specializers specializers 'specializer)))
+    ;; KLUDGE: ANSI says that it's not valid to have methods
+    ;; specializing on classes which are "not defined", leaving
+    ;; unclear what the definedness of a class is; AMOP suggests that
+    ;; forward-referenced-classes, since they have proper names and
+    ;; all, are at least worthy of some level of definition.  We allow
+    ;; methods specialized on forward-referenced-classes, but it's
+    ;; non-portable and potentially dubious, so
+    (let ((frcs (remove-if-not #'forward-referenced-class-p specializers)))
+      (unless (null frcs)
+        (style-warn "~@<Defining a method using ~
+                     ~V[~;~1{~S~}~;~1{~S and ~S~}~:;~{~#[~;and ~]~S~^, ~}~] ~
+                     as ~2:*~V[~;a specializer~:;specializers~].~@:>"
+                    (length frcs) frcs)))))
+
+(defmethod shared-initialize :before
+    ((method standard-method) slot-names &key
+     qualifiers lambda-list specializers function documentation)
   (declare (ignore slot-names))
-  (flet ((lose (initarg value string)
-           (error "when initializing the method ~S:~%~
-                   The ~S initialization argument was: ~S.~%~
-                   which ~A."
-                  method initarg value string)))
-    (let ((check-qualifiers    (legal-qualifiers-p method qualifiers))
-          (check-lambda-list   (legal-lambda-list-p method lambda-list))
-          (check-specializers  (legal-specializers-p method specializers))
-          (check-fun (legal-method-function-p method
-                                              (or function
-                                                  fast-function)))
-          (check-documentation (legal-documentation-p method documentation)))
-      (unless (eq check-qualifiers t)
-        (lose :qualifiers qualifiers check-qualifiers))
-      (unless (eq check-lambda-list t)
-        (lose :lambda-list lambda-list check-lambda-list))
-      (unless (eq check-specializers t)
-        (lose :specializers specializers check-specializers))
-      (unless (eq check-fun t)
-        (lose :function function check-fun))
-      (unless (eq check-documentation t)
-        (lose :documentation documentation check-documentation)))))
-
-(defmethod shared-initialize :before ((method standard-accessor-method)
-                                      slot-names
-                                      &key slot-name slot-definition)
+  ;; FIXME: it's not clear to me (CSR, 2006-08-09) why methods get
+  ;; this extra paranoia and nothing else does; either everything
+  ;; should be aggressively checking initargs, or nothing much should.
+  ;; In either case, it would probably be better to have :type
+  ;; declarations in slots, which would then give a suitable type
+  ;; error (if we implement type-checking for slots...) rather than
+  ;; this hand-crafted thing.
+  (check-qualifiers method qualifiers)
+  (check-lambda-list method lambda-list)
+  (check-specializers method specializers)
+  (check-method-function method function)
+  (check-documentation method documentation))
+
+(defmethod shared-initialize :before
+    ((method standard-accessor-method) slot-names &key
+     slot-name slot-definition)
   (declare (ignore slot-names))
   (unless slot-definition
-    (let ((legalp (legal-slot-name-p method slot-name)))
-      ;; FIXME: nasty convention; should be renamed to ILLEGAL-SLOT-NAME-P and
-      ;; ILLEGALP, and the convention redone to be less twisty
-      (unless (eq legalp t)
-        (error "The value of the :SLOT-NAME initarg ~A." legalp)))))
+    (check-slot-name method slot-name)))
 
 (defmethod shared-initialize :after ((method standard-method) slot-names
-                                     &rest initargs
-                                     &key qualifiers method-spec plist)
-  (declare (ignore slot-names method-spec plist))
-  (initialize-method-function initargs nil method)
-  (setf (plist-value method 'qualifiers) qualifiers)
-  #+ignore
-  (setf (slot-value method 'closure-generator)
-        (method-function-closure-generator (slot-value method 'function))))
-
-(defmethod shared-initialize :after ((method standard-accessor-method)
-                                     slot-names
-                                     &key)
+                                     &rest initargs &key)
   (declare (ignore slot-names))
-  (with-slots (slot-name slot-definition)
-    method
-    (unless slot-definition
-      (let ((class (accessor-method-class method)))
-        (when (slot-class-p class)
-          (setq slot-definition (find slot-name (class-direct-slots class)
-                                      :key #'slot-definition-name)))))
-    (when (and slot-definition (null slot-name))
-      (setq slot-name (slot-definition-name slot-definition)))))
-
-(defmethod method-qualifiers ((method standard-method))
-  (plist-value method 'qualifiers))
+  (initialize-method-function initargs method))
+
 
 (defvar *the-class-generic-function*
   (find-class 'generic-function))
@@ -248,41 +204,19 @@
              (initarg-error :method-combination
                             method-combination
                             "a method combination object")))
-          ((slot-boundp generic-function 'method-combination))
+          ((slot-boundp generic-function '%method-combination))
           (t
            (initarg-error :method-combination
                           "not supplied"
                           "a method combination object")))))
-
-#||
-(defmethod reinitialize-instance ((generic-function standard-generic-function)
-                                  &rest initargs
-                                  &key name
-                                       lambda-list
-                                       argument-precedence-order
-                                       declarations
-                                       documentation
-                                       method-class
-                                       method-combination)
-  (declare (ignore documentation declarations argument-precedence-order
-                   lambda-list name method-class method-combination))
-  (macrolet ((add-initarg (check name slot-name)
-               `(unless ,check
-                  (push (slot-value generic-function ,slot-name) initargs)
-                  (push ,name initargs))))
-;   (add-initarg name :name 'name)
-;   (add-initarg lambda-list :lambda-list 'lambda-list)
-;   (add-initarg argument-precedence-order
-;                :argument-precedence-order
-;                'argument-precedence-order)
-;   (add-initarg declarations :declarations 'declarations)
-;   (add-initarg documentation :documentation 'documentation)
-;   (add-initarg method-class :method-class 'method-class)
-;   (add-initarg method-combination :method-combination 'method-combination)
-    (apply #'call-next-method generic-function initargs)))
-||#
 
-;;; These two are scheduled for demolition.
+(defun find-generic-function (name &optional (errorp t))
+  (let ((fun (and (fboundp name) (fdefinition name))))
+    (cond
+      ((and fun (typep fun 'generic-function)) fun)
+      (errorp (error "No generic function named ~S." name))
+      (t nil))))
+
 (defun real-add-named-method (generic-function-name
                               qualifiers
                               specializers
@@ -292,11 +226,13 @@
                (typep (fdefinition generic-function-name) 'generic-function))
     (style-warn "implicitly creating new generic function ~S"
                 generic-function-name))
-  ;; XXX What about changing the class of the generic function if
-  ;; there is one? Whose job is that, anyway? Do we need something
-  ;; kind of like CLASS-FOR-REDEFINITION?
-  (let* ((generic-function
-           (ensure-generic-function generic-function-name))
+  (let* ((existing-gf (find-generic-function generic-function-name nil))
+         (generic-function
+          (if existing-gf
+              (ensure-generic-function
+               generic-function-name
+               :generic-function-class (class-of existing-gf))
+              (ensure-generic-function generic-function-name)))
          (specs (parse-specializers specializers))
          (proto (method-prototype-for-gf generic-function-name))
          (new (apply #'make-instance (class-of proto)
@@ -487,6 +423,18 @@
   (loop (when (null methods) (return gf))
         (real-add-method gf (pop methods) methods)))
 
+(define-condition new-value-specialization (reference-condition error)
+  ((%method :initarg :method :reader new-value-specialization-method))
+  (:report
+   (lambda (c s)
+     (format s "~@<Cannot add method ~S to ~S, as it specializes the ~
+                new-value argument.~@:>"
+             (new-value-specialization-method c)
+             #'(setf slot-value-using-class))))
+  (:default-initargs :references
+      (list '(:sbcl :node "Metaobject Protocol")
+            '(:amop :generic-function (setf slot-value-using-class)))))
+
 (defun real-add-method (generic-function method &optional skip-dfun-update-p)
   (when (method-generic-function method)
     (error "~@<The method ~S is already part of the generic ~
@@ -517,6 +465,17 @@
         (when (and existing (similar-lambda-lists-p existing method))
           (remove-method generic-function existing))
 
+        ;; KLUDGE: We have a special case here, as we disallow
+        ;; specializations of the NEW-VALUE argument to (SETF
+        ;; SLOT-VALUE-USING-CLASS).  GET-ACCESSOR-METHOD-FUNCTION is
+        ;; the optimizing function here: it precomputes the effective
+        ;; method, assuming that there is no dispatch to be done on
+        ;; the new-value argument.
+        (when (and (eq generic-function #'(setf slot-value-using-class))
+                   (not (eq *the-class-t* (first specializers))))
+          (error 'new-value-specialization
+                 :method method))
+
         (setf (method-generic-function method) generic-function)
         (pushnew method (generic-function-methods generic-function))
         (dolist (specializer specializers)
@@ -553,7 +512,7 @@
                       in method ~S:~2I~_~S.~@:>"
                      method qualifiers)))
             ((short-method-combination-p mc)
-             (let ((mc-name (method-combination-type mc)))
+             (let ((mc-name (method-combination-type-name mc)))
                (when (or (null qualifiers)
                          (cdr qualifiers)
                          (and (neq (car qualifiers) :around)
@@ -574,7 +533,7 @@
         generic-function)))
 
 (defun real-remove-method (generic-function method)
-  (when  (eq generic-function (method-generic-function method))
+  (when (eq generic-function (method-generic-function method))
     (let* ((name (generic-function-name generic-function))
            (specializers (method-specializers method))
            (methods (generic-function-methods generic-function))
@@ -591,8 +550,8 @@
       (map-dependents generic-function
                       (lambda (dep)
                         (update-dependent generic-function
-                                          dep 'remove-method method)))
-      generic-function)))
+                                          dep 'remove-method method)))))
+  generic-function)
 
 (defun compute-applicable-methods-function (generic-function arguments)
   (values (compute-applicable-methods-using-types
@@ -651,7 +610,7 @@
    ))
 
 (defmethod same-specializer-p ((specl1 specializer) (specl2 specializer))
-  nil)
+  (eql specl1 specl2))
 
 (defmethod same-specializer-p ((specl1 class) (specl2 class))
   (eq specl1 specl2))
@@ -670,14 +629,23 @@
 (defmethod specializer-class ((specializer eql-specializer))
   (class-of (slot-value specializer 'object)))
 
-(defvar *in-gf-arg-info-p* nil)
-(setf (gdefinition 'arg-info-reader)
-      (let ((mf (initialize-method-function
-                 (make-internal-reader-method-function
-                  'standard-generic-function 'arg-info)
-                 t)))
-        (lambda (&rest args) (funcall mf args nil))))
+;;; KLUDGE: this is needed to allow for user-defined specializers in
+;;; RAISE-METATYPE; however, the list of methods is maintained by
+;;; hand, which is error-prone.  We can't just add a method to
+;;; SPECIALIZER-CLASS, or at least not with confidence, as that
+;;; function is used elsewhere in PCL.  `STANDARD' here is used in the
+;;; sense of `comes with PCL' rather than `blessed by the
+;;; authorities'.  -- CSR, 2007-05-10
+(defmethod standard-specializer-p ((specializer class)) t)
+(defmethod standard-specializer-p ((specializer eql-specializer)) t)
+(defmethod standard-specializer-p ((specializer class-eq-specializer)) t)
+(defmethod standard-specializer-p ((specializer class-prototype-specializer))
+  t)
+(defmethod standard-specializer-p ((specializer specializer)) nil)
 
+(defun specializer-class-or-nil (specializer)
+  (and (standard-specializer-p specializer)
+       (specializer-class specializer)))
 
 (defun error-need-at-least-n-args (function n)
   (error 'simple-program-error
@@ -724,9 +692,7 @@
 (defun value-for-caching (gf classes)
   (let ((methods (compute-applicable-methods-using-types
                    gf (mapcar #'class-eq-type classes))))
-    (method-function-get (or (method-fast-function (car methods))
-                             (method-function (car methods)))
-                         :constant-value)))
+    (method-plist-value (car methods) :constant-value)))
 
 (defun default-secondary-dispatch-function (generic-function)
   (lambda (&rest args)
@@ -805,16 +771,17 @@
     (setf (gf-info-simple-accessor-type arg-info)
           (let* ((methods (generic-function-methods gf))
                  (class (and methods (class-of (car methods))))
-                 (type (and class
-                            (cond ((eq class
-                                       *the-class-standard-reader-method*)
-                                   'reader)
-                                  ((eq class
-                                       *the-class-standard-writer-method*)
-                                   'writer)
-                                  ((eq class
-                                       *the-class-standard-boundp-method*)
-                                   'boundp)))))
+                 (type
+                  (and class
+                       (cond ((or (eq class *the-class-standard-reader-method*)
+                                  (eq class *the-class-global-reader-method*))
+                              'reader)
+                             ((or (eq class *the-class-standard-writer-method*)
+                                  (eq class *the-class-global-writer-method*))
+                              'writer)
+                             ((or (eq class *the-class-standard-boundp-method*)
+                                  (eq class *the-class-global-boundp-method*))
+                              'boundp)))))
             (when (and (gf-info-c-a-m-emf-std-p arg-info)
                        type
                        (dolist (method (cdr methods) t)
@@ -875,13 +842,13 @@
   (unless *new-class*
     (update-std-or-str-methods gf type))
   (when (and (standard-svuc-method type) (structure-svuc-method type))
-    (flet ((update-class (class)
+    (flet ((update-accessor-info (class)
              (when (class-finalized-p class)
                (dolist (slotd (class-slots class))
                  (compute-slot-accessor-info slotd type gf)))))
       (if *new-class*
-          (update-class *new-class*)
-          (map-all-classes #'update-class 'slot-object)))))
+          (update-accessor-info *new-class*)
+          (map-all-classes #'update-accessor-info 'slot-object)))))
 
 (defvar *standard-slot-value-using-class-method* nil)
 (defvar *standard-setf-slot-value-using-class-method* nil)
@@ -952,18 +919,20 @@
                (set-structure-svuc-method type method)))))))
 
 (defun mec-all-classes-internal (spec precompute-p)
-  (cons (specializer-class spec)
-        (and (classp spec)
-             precompute-p
-             (not (or (eq spec *the-class-t*)
-                      (eq spec *the-class-slot-object*)
-                      (eq spec *the-class-standard-object*)
-                      (eq spec *the-class-structure-object*)))
-             (let ((sc (class-direct-subclasses spec)))
-               (when sc
-                 (mapcan (lambda (class)
-                           (mec-all-classes-internal class precompute-p))
-                         sc))))))
+  (let ((wrapper (class-wrapper (specializer-class spec))))
+    (unless (or (not wrapper) (invalid-wrapper-p wrapper))
+      (cons (specializer-class spec)
+            (and (classp spec)
+                 precompute-p
+                 (not (or (eq spec *the-class-t*)
+                          (eq spec *the-class-slot-object*)
+                          (eq spec *the-class-standard-object*)
+                          (eq spec *the-class-structure-object*)))
+                 (let ((sc (class-direct-subclasses spec)))
+                   (when sc
+                     (mapcan (lambda (class)
+                               (mec-all-classes-internal class precompute-p))
+                             sc))))))))
 
 (defun mec-all-classes (spec precompute-p)
   (let ((classes (mec-all-classes-internal spec precompute-p)))
@@ -1000,17 +969,26 @@
          (default '(default)))
     (flet ((add-class-list (classes)
              (when (or (null new-class) (memq new-class classes))
-               (let ((wrappers (get-wrappers-from-classes
-                                nkeys wrappers classes metatypes)))
-                 (when (and wrappers
-                            (eq default (probe-cache cache wrappers default)))
+               (let ((%wrappers (get-wrappers-from-classes
+                                 nkeys wrappers classes metatypes)))
+                 (when (and %wrappers
+                            (eq default (probe-cache cache %wrappers default)))
                    (let ((value (cond ((eq valuep t)
                                        (sdfun-for-caching generic-function
                                                           classes))
                                       ((eq valuep :constant-value)
                                        (value-for-caching generic-function
                                                           classes)))))
-                     (setq cache (fill-cache cache wrappers value))))))))
+                     ;; need to get them again, as finalization might
+                     ;; have happened in between, which would
+                     ;; invalidate wrappers.
+                     (let ((wrappers (get-wrappers-from-classes
+                                      nkeys wrappers classes metatypes)))
+                       (when (if (atom wrappers)
+                                 (not (invalid-wrapper-p wrappers))
+                                 (every (complement #'invalid-wrapper-p)
+                                        wrappers))
+                         (setq cache (fill-cache cache wrappers value))))))))))
       (if classes-list
           (mapc #'add-class-list classes-list)
           (dolist (method (generic-function-methods generic-function))
@@ -1283,7 +1261,8 @@
   (if (atom form)
       (default-test-converter form)
       (case (car form)
-        ((invoke-effective-method-function invoke-fast-method-call)
+        ((invoke-effective-method-function invoke-fast-method-call
+          invoke-effective-narrow-method-function)
          '.call.)
         (methods
          '.methods.)
@@ -1376,20 +1355,20 @@
     (let* ((name (generic-function-name generic-function))
            (arg-info (gf-arg-info generic-function))
            (metatypes (arg-info-metatypes arg-info))
+           (nargs (length metatypes))
            (applyp (arg-info-applyp arg-info))
-           (fmc-arg-info (cons (length metatypes) applyp))
+           (fmc-arg-info (cons nargs applyp))
            (arglist (if function-p
-                        (make-dfun-lambda-list metatypes applyp)
-                        (make-fast-method-call-lambda-list metatypes applyp))))
+                        (make-dfun-lambda-list nargs applyp)
+                        (make-fast-method-call-lambda-list nargs applyp))))
       (multiple-value-bind (cfunction constants)
           (get-fun1 `(lambda
                       ,arglist
                       ,@(unless function-p
-                          `((declare (ignore .pv-cell.
-                                             .next-method-call.))))
+                          `((declare (ignore .pv-cell. .next-method-call.))))
                       (locally (declare #.*optimize-speed*)
                                (let ((emf ,net))
-                                 ,(make-emf-call metatypes applyp 'emf))))
+                                 ,(make-emf-call nargs applyp 'emf))))
                     #'net-test-converter
                     #'net-code-converter
                     (lambda (form)
@@ -1520,53 +1499,62 @@
   (declare (ignore class))
   (function-funcall (slot-definition-boundp-function slotd) object))
 
+(defun special-case-for-compute-discriminating-function-p (gf)
+  (or (eq gf #'slot-value-using-class)
+      (eq gf #'(setf slot-value-using-class))
+      (eq gf #'slot-boundp-using-class)))
+
 (defmethod compute-discriminating-function ((gf standard-generic-function))
   (with-slots (dfun-state arg-info) gf
+    (when (special-case-for-compute-discriminating-function-p gf)
+      ;; if we have a special case for
+      ;; COMPUTE-DISCRIMINATING-FUNCTION, then (at least for the
+      ;; special cases implemented as of 2006-05-09) any information
+      ;; in the cache is misplaced.
+      (aver (null dfun-state)))
     (typecase dfun-state
-      (null (let ((name (generic-function-name gf)))
-              (when (eq name 'compute-applicable-methods)
-                (update-all-c-a-m-gf-info gf))
-              (cond ((eq name 'slot-value-using-class)
-                     (update-slot-value-gf-info gf 'reader)
-                     #'slot-value-using-class-dfun)
-                    ((equal name '(setf slot-value-using-class))
-                     (update-slot-value-gf-info gf 'writer)
-                     #'setf-slot-value-using-class-dfun)
-                    ((eq name 'slot-boundp-using-class)
-                     (update-slot-value-gf-info gf 'boundp)
-                     #'slot-boundp-using-class-dfun)
-                    ((gf-precompute-dfun-and-emf-p arg-info)
-                     (make-final-dfun gf))
-                    (t
-                     (make-initial-dfun gf)))))
+      (null
+       (when (eq gf #'compute-applicable-methods)
+         (update-all-c-a-m-gf-info gf))
+       (cond
+         ((eq gf #'slot-value-using-class)
+          (update-slot-value-gf-info gf 'reader)
+          #'slot-value-using-class-dfun)
+         ((eq gf #'(setf slot-value-using-class))
+          (update-slot-value-gf-info gf 'writer)
+          #'setf-slot-value-using-class-dfun)
+         ((eq gf #'slot-boundp-using-class)
+          (update-slot-value-gf-info gf 'boundp)
+          #'slot-boundp-using-class-dfun)
+         ((gf-precompute-dfun-and-emf-p arg-info)
+          (make-final-dfun gf))
+         (t
+          (make-initial-dfun gf))))
       (function dfun-state)
       (cons (car dfun-state)))))
 
 (defmethod update-gf-dfun ((class std-class) gf)
   (let ((*new-class* class)
-        #|| (name (generic-function-name gf)) ||#
         (arg-info (gf-arg-info gf)))
-    (cond #||
-          ((eq name 'slot-value-using-class)
-           (update-slot-value-gf-info gf 'reader))
-          ((equal name '(setf slot-value-using-class))
-           (update-slot-value-gf-info gf 'writer))
-          ((eq name 'slot-boundp-using-class)
-           (update-slot-value-gf-info gf 'boundp))
-          ||#
-          ((gf-precompute-dfun-and-emf-p arg-info)
-           (multiple-value-bind (dfun cache info)
-               (make-final-dfun-internal gf)
-             (set-dfun gf dfun cache info) ; lest the cache be freed twice
-             (update-dfun gf dfun cache info))))))
+    (cond
+      ((special-case-for-compute-discriminating-function-p gf))
+      ((gf-precompute-dfun-and-emf-p arg-info)
+       (multiple-value-bind (dfun cache info)
+           (make-final-dfun-internal gf)
+         (set-dfun gf dfun cache info) ; lest the cache be freed twice
+         (update-dfun gf dfun cache info))))))
 
-(defun (setf class-name) (new-value class)
-  (let ((classoid (%wrapper-classoid (class-wrapper class))))
-    (setf (classoid-name classoid) new-value))
-  (reinitialize-instance class :name new-value))
-
-(defun (setf generic-function-name) (new-value generic-function)
-  (reinitialize-instance generic-function :name new-value))
+(defmethod (setf class-name) (new-value class)
+  (let ((classoid (wrapper-classoid (class-wrapper class))))
+    (if (and new-value (symbolp new-value))
+        (setf (classoid-name classoid) new-value)
+        (setf (classoid-name classoid) nil)))
+  (reinitialize-instance class :name new-value)
+  new-value)
+
+(defmethod (setf generic-function-name) (new-value generic-function)
+  (reinitialize-instance generic-function :name new-value)
+  new-value)
 
 (defmethod function-keywords ((method standard-method))
   (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p keywords)