- (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))
-
- (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 name)
+ (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))
+ (when (and (eq name 'print-object) (not (eq (second specializers) *the-class-t*)))
+ (warn 'print-object-stream-specializer))
+ (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))
+ (setf (gf-info-needs-update generic-function) t)
+ (map-dependents generic-function
+ (lambda (dep)
+ (update-dependent generic-function
+ dep 'add-method method)))))
+ (serious-condition (c)
+ (error c)))))
+ generic-function)