X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fpcl%2Fmethods.lisp;h=d2e5d9c7429f5a8bd3e1c0705e0846428ce7b34b;hb=8ee41eac134a552e07e966dd16d681e8216147fc;hp=d9e2ac84c90ff0090411164bdc8a454411ef6e04;hpb=b1a1d1280f0003e0d5af9996274c95a78f188b37;p=sbcl.git

diff --git a/src/pcl/methods.lisp b/src/pcl/methods.lisp
index d9e2ac8..d2e5d9c 100644
--- a/src/pcl/methods.lisp
+++ b/src/pcl/methods.lisp
@@ -152,10 +152,9 @@
     (check-slot-name method slot-name)))
 
 (defmethod shared-initialize :after ((method standard-method) slot-names
-                                     &rest initargs &key)
-  (declare (ignore slot-names))
+                                     &rest initargs &key ((method-cell method-cell)))
+  (declare (ignore slot-names method-cell))
   (initialize-method-function initargs method))
-
 
 (defvar *the-class-generic-function*
   (find-class 'generic-function))
@@ -217,15 +216,11 @@
       (errorp (error "No generic function named ~S." name))
       (t nil))))
 
-(defun real-add-named-method (generic-function-name
-                              qualifiers
-                              specializers
-                              lambda-list
-                              &rest other-initargs)
+(defun real-add-named-method (generic-function-name qualifiers
+                              specializers lambda-list &rest other-initargs)
   (unless (and (fboundp generic-function-name)
                (typep (fdefinition generic-function-name) 'generic-function))
-    (style-warn "implicitly creating new generic function ~S"
-                generic-function-name))
+    (warn 'implicit-generic-function-warning :name generic-function-name))
   (let* ((existing-gf (find-generic-function generic-function-name nil))
          (generic-function
           (if existing-gf
@@ -233,15 +228,15 @@
                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)
-                                     :qualifiers qualifiers
-                                     :specializers specs
-                                     :lambda-list lambda-list
-                                     other-initargs)))
-    (add-method generic-function new)
-    new))
+         (proto (method-prototype-for-gf generic-function-name)))
+    ;; FIXME: Destructive modification of &REST list.
+    (setf (getf (getf other-initargs 'plist) :name)
+          (make-method-spec generic-function qualifiers specializers))
+    (let ((new (apply #'make-instance (class-of proto)
+                      :qualifiers qualifiers :specializers specializers
+                      :lambda-list lambda-list other-initargs)))
+      (add-method generic-function new)
+      new)))
 
 (define-condition find-method-length-mismatch
     (reference-condition simple-error)
@@ -290,11 +285,14 @@
   ;; function, or an error is signaled."
   ;;
   ;; This error checking is done by REAL-GET-METHOD.
-  (real-get-method generic-function
-                   qualifiers
-                   (parse-specializers specializers)
-                   errorp
-                   t))
+  (real-get-method
+   generic-function qualifiers
+   ;; ANSI for FIND-METHOD seems to imply that in fact specializers
+   ;; should always be passed in parsed form instead of being parsed
+   ;; at this point.  Since there's no ANSI-blessed way of getting an
+   ;; EQL specializer, that seems unnecessarily painful, so we are
+   ;; nice to our users.  -- CSR, 2007-06-01
+   (parse-specializers generic-function specializers) errorp t))
 
 ;;; Compute various information about a generic-function's arglist by looking
 ;;; at the argument lists of the methods. The hair for trying not to use
@@ -347,7 +345,7 @@
     (let ((pos 0))
       (dolist (type-spec (method-specializers method))
         (unless (eq type-spec *the-class-t*)
-          (pushnew pos specialized-argument-positions))
+          (pushnew pos specialized-argument-positions :test #'eq))
         (incf pos)))
     ;; Finally merge the values for this method into the values
     ;; for the exisiting methods and return them. Note that if
@@ -435,122 +433,151 @@
       (list '(:sbcl :node "Metaobject Protocol")
             '(:amop :generic-function (setf slot-value-using-class)))))
 
+(defgeneric values-for-add-method (gf method)
+  (:method ((gf standard-generic-function) (method standard-method))
+    ;; KLUDGE: Just a single generic dispatch, and everything else
+    ;; comes from permutation vectors. Would be nicer to define
+    ;; REAL-ADD-METHOD with a proper method so that we could efficiently
+    ;; use SLOT-VALUE there.
+    ;;
+    ;; Optimization note: REAL-ADD-METHOD has a lot of O(N) stuff in it (as
+    ;; does PCL as a whole). It should not be too hard to internally store
+    ;; many of the things we now keep in lists as either purely functional
+    ;; O(log N) sets, or --if we don't mind the memory cost-- using
+    ;; specialized hash-tables: most things are used to answer questions about
+    ;; set-membership, not ordering.
+    (values (slot-value gf '%lock)
+            (slot-value method 'qualifiers)
+            (slot-value method 'specializers)
+            (slot-value method 'lambda-list)
+            (slot-value method '%generic-function))))
+
 (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 ~
-            function ~S; it can't be added to another generic ~
-            function until it is removed from the first one.~@:>"
-           method (method-generic-function method)))
-  (flet ((similar-lambda-lists-p (method-a method-b)
+  (flet ((similar-lambda-lists-p (old-method new-lambda-list)
            (multiple-value-bind (a-nreq a-nopt a-keyp a-restp)
-               (analyze-lambda-list (method-lambda-list method-a))
+               (analyze-lambda-list (method-lambda-list old-method))
              (multiple-value-bind (b-nreq b-nopt b-keyp b-restp)
-                 (analyze-lambda-list (method-lambda-list method-b))
+                 (analyze-lambda-list new-lambda-list)
                (and (= a-nreq b-nreq)
                     (= a-nopt b-nopt)
                     (eq (or a-keyp a-restp)
                         (or b-keyp b-restp)))))))
-      (let* ((name (generic-function-name generic-function))
-             (qualifiers (method-qualifiers method))
-             (specializers (method-specializers method))
-             (existing (get-method generic-function
-                                   qualifiers
-                                   specializers
-                                   nil)))
-
-        ;; If there is already a method like this one then we must get
-        ;; rid of it before proceeding.  Note that we call the generic
-        ;; function REMOVE-METHOD to remove it rather than doing it in
-        ;; some internal way.
-        (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)
-          (add-direct-method specializer method))
-
-        ;; KLUDGE: SET-ARG-INFO contains the error-detecting logic for
-        ;; detecting attempts to add methods with incongruent lambda
-        ;; lists.  However, according to Gerd Moellmann on cmucl-imp,
-        ;; it also depends on the new method already having been added
-        ;; to the generic function.  Therefore, we need to remove it
-        ;; again on error:
-        (let ((remove-again-p t))
-          (unwind-protect
-               (progn
-                 (set-arg-info generic-function :new-method method)
-                 (setq remove-again-p nil))
-            (when remove-again-p
-              (remove-method generic-function method))))
-
-        ;; KLUDGE II: ANSI saith that it is not an error to add a
-        ;; method with invalid qualifiers to a generic function of the
-        ;; wrong kind; it's only an error at generic function
-        ;; invocation time; I dunno what the rationale was, and it
-        ;; sucks.  Nevertheless, it's probably a programmer error, so
-        ;; let's warn anyway. -- CSR, 2003-08-20
-        (let ((mc (generic-function-method-combination generic-functioN)))
-          (cond
-            ((eq mc *standard-method-combination*)
-             (when (and qualifiers
-                        (or (cdr qualifiers)
-                            (not (memq (car qualifiers)
-                                       '(:around :before :after)))))
-               (warn "~@<Invalid qualifiers for standard method combination ~
-                      in method ~S:~2I~_~S.~@:>"
-                     method qualifiers)))
-            ((short-method-combination-p mc)
-             (let ((mc-name (method-combination-type-name mc)))
-               (when (or (null qualifiers)
-                         (cdr qualifiers)
-                         (and (neq (car qualifiers) :around)
-                              (neq (car qualifiers) mc-name)))
-                 (warn "~@<Invalid qualifiers for ~S method combination ~
-                        in method ~S:~2I~_~S.~@:>"
-                       mc-name method qualifiers))))))
-
-        (unless skip-dfun-update-p
-          (update-ctors 'add-method
-                        :generic-function generic-function
-                        :method method)
-          (update-dfun generic-function))
-        (map-dependents generic-function
-                        (lambda (dep)
-                          (update-dependent generic-function
-                                            dep 'add-method method)))
-        generic-function)))
+    (multiple-value-bind (lock qualifiers specializers new-lambda-list
+                          method-gf)
+        (values-for-add-method generic-function method)
+      (when method-gf
+        (error "~@<The method ~S is already part of the generic ~
+                function ~S; it can't be added to another generic ~
+                function until it is removed from the first one.~@:>"
+               method method-gf))
+      (handler-case
+          ;; System lock because interrupts need to be disabled as
+          ;; well: it would be bad to unwind and leave the gf in an
+          ;; inconsistent state.
+          (sb-thread::with-recursive-system-spinlock (lock)
+            (let ((existing (get-method generic-function
+                                        qualifiers
+                                        specializers
+                                        nil)))
+
+              ;; If there is already a method like this one then we must get
+              ;; rid of it before proceeding.  Note that we call the generic
+              ;; function REMOVE-METHOD to remove it rather than doing it in
+              ;; some internal way.
+              (when (and existing (similar-lambda-lists-p existing new-lambda-list))
+                (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) :test #'eq)
+              (dolist (specializer specializers)
+                (add-direct-method specializer method))
+
+              ;; KLUDGE: SET-ARG-INFO contains the error-detecting logic for
+              ;; detecting attempts to add methods with incongruent lambda
+              ;; lists.  However, according to Gerd Moellmann on cmucl-imp,
+              ;; it also depends on the new method already having been added
+              ;; to the generic function.  Therefore, we need to remove it
+              ;; again on error:
+              (let ((remove-again-p t))
+                (unwind-protect
+                     (progn
+                       (set-arg-info generic-function :new-method method)
+                       (setq remove-again-p nil))
+                  (when remove-again-p
+                    (remove-method generic-function method))))
+
+              ;; KLUDGE II: ANSI saith that it is not an error to add a
+              ;; method with invalid qualifiers to a generic function of the
+              ;; wrong kind; it's only an error at generic function
+              ;; invocation time; I dunno what the rationale was, and it
+              ;; sucks.  Nevertheless, it's probably a programmer error, so
+              ;; let's warn anyway. -- CSR, 2003-08-20
+              (let ((mc (generic-function-method-combination generic-functioN)))
+                (cond
+                  ((eq mc *standard-method-combination*)
+                   (when (and qualifiers
+                              (or (cdr qualifiers)
+                                  (not (memq (car qualifiers)
+                                             '(:around :before :after)))))
+                     (warn "~@<Invalid qualifiers for standard method ~
+                            combination in method ~S:~2I~_~S.~@:>"
+                           method qualifiers)))
+                  ((short-method-combination-p mc)
+                   (let ((mc-name (method-combination-type-name mc)))
+                     (when (or (null qualifiers)
+                               (cdr qualifiers)
+                               (and (neq (car qualifiers) :around)
+                                    (neq (car qualifiers) mc-name)))
+                       (warn "~@<Invalid qualifiers for ~S method combination ~
+                              in method ~S:~2I~_~S.~@:>"
+                             mc-name method qualifiers))))))
+
+              (unless skip-dfun-update-p
+                (update-ctors 'add-method
+                              :generic-function generic-function
+                              :method method)
+                (update-dfun generic-function))
+              (map-dependents generic-function
+                              (lambda (dep)
+                                (update-dependent generic-function
+                                                  dep 'add-method method)))))
+        (serious-condition (c)
+          (error c)))))
+  generic-function)
 
 (defun real-remove-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))
-           (new-methods (remove method methods)))
-      (setf (method-generic-function method) nil)
-      (setf (generic-function-methods generic-function) new-methods)
-      (dolist (specializer (method-specializers method))
-        (remove-direct-method specializer method))
-      (set-arg-info generic-function)
-      (update-ctors 'remove-method
-                    :generic-function generic-function
-                    :method method)
-      (update-dfun generic-function)
-      (map-dependents generic-function
-                      (lambda (dep)
-                        (update-dependent generic-function
-                                          dep 'remove-method method)))))
+    (let ((lock (gf-lock generic-function)))
+      ;; System lock because interrupts need to be disabled as well:
+      ;; it would be bad to unwind and leave the gf in an inconsistent
+      ;; state.
+      (sb-thread::with-recursive-system-spinlock (lock)
+        (let* ((specializers (method-specializers method))
+               (methods (generic-function-methods generic-function))
+               (new-methods (remove method methods)))
+          (setf (method-generic-function method) nil
+                (generic-function-methods generic-function) new-methods)
+          (dolist (specializer (method-specializers method))
+            (remove-direct-method specializer method))
+          (set-arg-info generic-function)
+          (update-ctors 'remove-method
+                        :generic-function generic-function
+                        :method method)
+          (update-dfun generic-function)
+          (map-dependents generic-function
+                          (lambda (dep)
+                            (update-dependent generic-function
+                                              dep 'remove-method method)))))))
   generic-function)
 
 (defun compute-applicable-methods-function (generic-function arguments)
@@ -579,7 +606,7 @@
   (dolist (class classes)
     (dolist (other-class classes)
       (unless (eq class other-class)
-        (pushnew other-class (class-incompatible-superclass-list class))))))
+        (pushnew other-class (class-incompatible-superclass-list class) :test #'eq)))))
 
 (defun superclasses-compatible-p (class1 class2)
   (let ((cpl1 (cpl-or-nil class1))
@@ -610,7 +637,7 @@
    ))
 
 (defmethod same-specializer-p ((specl1 specializer) (specl2 specializer))
-  nil)
+  (eql specl1 specl2))
 
 (defmethod same-specializer-p ((specl1 class) (specl2 class))
   (eq specl1 specl2))
@@ -629,21 +656,9 @@
 (defmethod specializer-class ((specializer eql-specializer))
   (class-of (slot-value specializer 'object)))
 
-;;; 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.  -- CSR, 2007-05-10
-(defmethod specializer-class-or-nil ((specializer specializer))
-  nil)
-(defmethod specializer-class-or-nil ((specializer eql-specializer))
-  (specializer-class specializer))
-(defmethod specializer-class-or-nil ((specializer class))
-  (specializer-class specializer))
-(defmethod specializer-class-or-nil ((specializer class-eq-specializer))
-  (specializer-class specializer))
-(defmethod specializer-class-or-nil ((specializer class-prototype-specializer))
-  (specializer-class specializer))
+(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
@@ -732,22 +747,23 @@
   (let ((methods (generic-function-methods c-a-m-gf)))
     (if (and *old-c-a-m-gf-methods*
              (every (lambda (old-method)
-                      (member old-method methods))
+                      (member old-method methods :test #'eq))
                     *old-c-a-m-gf-methods*))
         (let ((gfs-to-do nil)
               (gf-classes-to-do nil))
           (dolist (method methods)
-            (unless (member method *old-c-a-m-gf-methods*)
+            (unless (member method *old-c-a-m-gf-methods* :test #'eq)
               (let ((specl (car (method-specializers method))))
                 (if (eql-specializer-p specl)
-                    (pushnew (specializer-object specl) gfs-to-do)
-                    (pushnew (specializer-class specl) gf-classes-to-do)))))
+                    (pushnew (specializer-object specl) gfs-to-do :test #'eq)
+                    (pushnew (specializer-class specl) gf-classes-to-do :test #'eq)))))
           (map-all-generic-functions
            (lambda (gf)
-             (when (or (member gf gfs-to-do)
+             (when (or (member gf gfs-to-do :test #'eq)
                        (dolist (class gf-classes-to-do nil)
                          (member class
-                                 (class-precedence-list (class-of gf)))))
+                                 (class-precedence-list (class-of gf))
+                                 :test #'eq)))
                (update-c-a-m-gf-info gf)))))
         (map-all-generic-functions #'update-c-a-m-gf-info))
     (setq *old-c-a-m-gf-methods* methods)))
@@ -818,8 +834,8 @@
                  (get-optimized-std-slot-value-using-class-method-function
                   class slotd type))
                 (method-alist
-                 `((,(car (or (member std-method methods)
-                              (member str-method methods)
+                 `((,(car (or (member std-method methods :test #'eq)
+                              (member str-method methods :test #'eq)
                               (bug "error in ~S"
                                    'get-accessor-method-function)))
                     ,optimized-std-fun)))
@@ -963,14 +979,12 @@
          (nkeys (arg-info-nkeys arg-info))
          (metatypes (arg-info-metatypes arg-info))
          (wrappers (unless (eq nkeys 1) (make-list nkeys)))
-         (precompute-p (gf-precompute-dfun-and-emf-p arg-info))
-         (default '(default)))
+         (precompute-p (gf-precompute-dfun-and-emf-p arg-info)))
     (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)))
+                 (when (and %wrappers (not (probe-cache cache %wrappers)))
                    (let ((value (cond ((eq valuep t)
                                        (sdfun-for-caching generic-function
                                                           classes))
@@ -1363,7 +1377,7 @@
           (get-fun1 `(lambda
                       ,arglist
                       ,@(unless function-p
-                          `((declare (ignore .pv-cell. .next-method-call.))))
+                          `((declare (ignore .pv. .next-method-call.))))
                       (locally (declare #.*optimize-speed*)
                                (let ((emf ,net))
                                  ,(make-emf-call nargs applyp 'emf))))
@@ -1503,7 +1517,7 @@
       (eq gf #'slot-boundp-using-class)))
 
 (defmethod compute-discriminating-function ((gf standard-generic-function))
-  (with-slots (dfun-state arg-info) gf
+  (let ((dfun-state (slot-value gf 'dfun-state)))
     (when (special-case-for-compute-discriminating-function-p gf)
       ;; if we have a special case for
       ;; COMPUTE-DISCRIMINATING-FUNCTION, then (at least for the
@@ -1524,7 +1538,7 @@
          ((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)
+         ((gf-precompute-dfun-and-emf-p (slot-value gf 'arg-info))
           (make-final-dfun gf))
          (t
           (make-initial-dfun gf))))
@@ -1539,7 +1553,6 @@
       ((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))))))
 
 (defmethod (setf class-name) (new-value class)
@@ -1554,13 +1567,14 @@
   (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)
+(defmethod function-keyword-parameters ((method standard-method))
+  (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p
+                        keywords keyword-parameters)
       (analyze-lambda-list (if (consp method)
                                (early-method-lambda-list method)
                                (method-lambda-list method)))
-    (declare (ignore nreq nopt keysp restp))
-    (values keywords allow-other-keys-p)))
+    (declare (ignore nreq nopt keysp restp keywords))
+    (values keyword-parameters allow-other-keys-p)))
 
 (defun method-ll->generic-function-ll (ll)
   (multiple-value-bind
@@ -1572,67 +1586,59 @@
                      (eq s '&allow-other-keys)))
                ll)))
 
-;;; This is based on the rules of method lambda list congruency defined in
-;;; the spec. The lambda list it constructs is the pretty union of the
-;;; lambda lists of all the methods. It doesn't take method applicability
-;;; into account at all yet.
+;;; This is based on the rules of method lambda list congruency
+;;; defined in the spec. The lambda list it constructs is the pretty
+;;; union of the lambda lists of the generic function and of all its
+;;; methods.  It doesn't take method applicability into account at all
+;;; yet.
+
+;;; (Notice that we ignore &AUX variables as they're not part of the
+;;; "public interface" of a function.)
+
 (defmethod generic-function-pretty-arglist
            ((generic-function standard-generic-function))
-  (let ((methods (generic-function-methods generic-function)))
-    (if methods
-      (let ((arglist ()))
-        ;; arglist is constructed from the GF's methods - maybe with
-        ;; keys and rest stuff added
-        (multiple-value-bind (required optional rest key allow-other-keys)
-            (method-pretty-arglist (car methods))
-          (dolist (m (cdr methods))
-            (multiple-value-bind (method-key-keywords
-                                  method-allow-other-keys
-                                  method-key)
-                (function-keywords m)
-              ;; we've modified function-keywords to return what we want as
-              ;;  the third value, no other change here.
-              (declare (ignore method-key-keywords))
-              (setq key (union key method-key))
-              (setq allow-other-keys (or allow-other-keys
-                                         method-allow-other-keys))))
-          (when allow-other-keys
-            (setq arglist '(&allow-other-keys)))
-          (when key
-            (setq arglist (nconc (list '&key) key arglist)))
-          (when rest
-            (setq arglist (nconc (list '&rest rest) arglist)))
-          (when optional
-            (setq arglist (nconc (list '&optional) optional arglist)))
-          (nconc required arglist)))
-      ;; otherwise we take the lambda-list from the GF directly, with no
-      ;; other 'keys' added ...
-      (let ((lambda-list (generic-function-lambda-list generic-function)))
-        lambda-list))))
-
-(defmethod method-pretty-arglist ((method standard-method))
-  (let ((required ())
-        (optional ())
-        (rest nil)
-        (key ())
-        (allow-other-keys nil)
-        (state 'required)
-        (arglist (method-lambda-list method)))
-    (dolist (arg arglist)
-      (cond ((eq arg '&optional)         (setq state 'optional))
-            ((eq arg '&rest)             (setq state 'rest))
-            ((eq arg '&key)              (setq state 'key))
-            ((eq arg '&allow-other-keys) (setq allow-other-keys t))
-            ((memq arg lambda-list-keywords))
-            (t
-             (ecase state
-               (required (push arg required))
-               (optional (push arg optional))
-               (key      (push arg key))
-               (rest     (setq rest arg))))))
-    (values (nreverse required)
-            (nreverse optional)
-            rest
-            (nreverse key)
-            allow-other-keys)))
-
+  (let ((gf-lambda-list (generic-function-lambda-list generic-function))
+        (methods (generic-function-methods generic-function)))
+    (if (null methods)
+        gf-lambda-list
+        (multiple-value-bind (gf.required gf.optional gf.rest gf.keys gf.allowp)
+            (%split-arglist gf-lambda-list)
+          ;; Possibly extend the keyword parameters of the gf by
+          ;; additional key parameters of its methods:
+          (let ((methods.keys nil) (methods.allowp nil))
+            (dolist (m methods)
+              (multiple-value-bind (m.keyparams m.allow-other-keys)
+                  (function-keyword-parameters m)
+                (setq methods.keys (union methods.keys m.keyparams :key #'maybe-car))
+                (setq methods.allowp (or methods.allowp m.allow-other-keys))))
+            (let ((arglist '()))
+              (when (or gf.allowp methods.allowp)
+                (push '&allow-other-keys arglist))
+              (when (or gf.keys methods.keys)
+                ;; We make sure that the keys of the gf appear before
+                ;; those of its methods, since they're probably more
+                ;; generally appliable.
+                (setq arglist (nconc (list '&key) gf.keys
+                                     (nset-difference methods.keys gf.keys)
+                                     arglist)))
+              (when gf.rest
+                (setq arglist (nconc (list '&rest gf.rest) arglist)))
+              (when gf.optional
+                (setq arglist (nconc (list '&optional) gf.optional arglist)))
+              (nconc gf.required arglist)))))))
+
+(defun maybe-car (thing)
+  (if (listp thing)
+      (car thing)
+      thing))
+
+
+(defun %split-arglist (lambda-list)
+  ;; This function serves to shrink the number of returned values of
+  ;; PARSE-LAMBDA-LIST to something handier.
+  (multiple-value-bind (required optional restp rest keyp keys allowp
+                        auxp aux morep more-context more-count)
+      (parse-lambda-list lambda-list)
+    (declare (ignore restp keyp auxp aux morep))
+    (declare (ignore more-context more-count))
+    (values required optional rest keys allowp)))