;;; this an interned symbol. That means that the fast check to see
;;; whether a slot is unbound is to say (EQ <val> '..SLOT-UNBOUND..).
;;; That is considerably faster than looking at the value of a special
-;;; variable. Be careful, there are places in the code which actually
-;;; use ..SLOT-UNBOUND.. rather than this variable. So much for
-;;; modularity..
+;;; variable.
;;;
-;;; FIXME: Now that we're tightly integrated into SBCL, we could use
-;;; the SBCL built-in unbound value token instead. Perhaps if we did
-;;; so it would be a good idea to define collections of CLOS slots as
-;;; a new type of heap object, instead of using bare SIMPLE-VECTOR, in
-;;; order to avoid problems (in the debugger if nowhere else) with
-;;; SIMPLE-VECTORs some of whose elements are unbound tokens.
-(defconstant +slot-unbound+ '..slot-unbound..)
+;;; It seems only reasonable to also export this for users, since
+;;; otherwise dealing with STANDARD-INSTANCE-ACCESS becomes harder
+;;; -- and slower -- than it needs to be.
+(defconstant +slot-unbound+ '..slot-unbound..
+ "SBCL specific extentions to MOP: if this value is read from an
+instance using STANDARD-INSTANCE-ACCESS, the slot is unbound.
+Similarly, an :INSTANCE allocated slot can be made unbound by
+assigning this to it using (SETF STANDARD-INSTANCE-ACCESS).
+
+Value of +SLOT-UNBOUND+ is unspecified, and should not be relied to be
+of any particular type, but it is guaranteed to be suitable for EQ
+comparison.")
(defmacro %allocate-static-slot-storage--class (no-of-slots)
`(make-array ,no-of-slots :initial-element +slot-unbound+))
(defun set-fun-name (fun new-name)
#+sb-doc
"Set the name of a compiled function object. Return the function."
- (declare (special *boot-state* *the-class-standard-generic-function*))
(when (valid-function-name-p fun)
(setq fun (fdefinition fun)))
(typecase fun
(sb-eval:interpreted-function
(setf (sb-eval:interpreted-function-name fun) new-name))
(funcallable-instance ;; KLUDGE: probably a generic function...
- (cond ((if (eq *boot-state* 'complete)
+ (cond ((if (eq **boot-state** 'complete)
(typep fun 'generic-function)
(eq (class-of fun) *the-class-standard-generic-function*))
(setf (%funcallable-instance-info fun 2) new-name))
(member (dsd-name included-slot) slot-overrides :test #'eq))
collect slot)))))
+(defun uninitialized-accessor-function (type slotd)
+ (lambda (&rest args)
+ (declare (ignore args))
+ (error "~:(~A~) function~@[ for ~S ~] not yet initialized."
+ type slotd)))
+
(defun structure-slotd-name (slotd)
(dsd-name slotd))
(dsd-accessor-name slotd))
(defun structure-slotd-reader-function (slotd)
- (fdefinition (dsd-accessor-name slotd)))
+ (let ((name (dsd-accessor-name slotd)))
+ (if (fboundp name)
+ (fdefinition name)
+ (uninitialized-accessor-function :reader slotd))))
(defun structure-slotd-writer-function (type slotd)
(if (dsd-read-only slotd)
(let ((dd (find-defstruct-description type)))
(coerce (slot-setter-lambda-form dd slotd) 'function))
- (fdefinition `(setf ,(dsd-accessor-name slotd)))))
+ (let ((name `(setf ,(dsd-accessor-name slotd))))
+ (if (fboundp name)
+ (fdefinition name)
+ (uninitialized-accessor-function :writer slotd)))))
(defun structure-slotd-type (slotd)
(dsd-type slotd))