ecl/src/clos/std-accessors.lsp

155 lines
7.1 KiB
Common Lisp

;;;; -*- Mode: Lisp; Syntax: Common-Lisp; indent-tabs-mode: nil; Package: CLOS -*-
;;;; vim: set filetype=lisp tabstop=8 shiftwidth=2 expandtab:
;;;;
;;;; Copyright (c) 1992, Giuseppe Attardi.o
;;;; Copyright (c) 2001, Juan Jose Garcia Ripoll.
;;;;
;;;; See file 'LICENSE' for the copyright details.
(in-package "CLOS")
;;; ----------------------------------------------------------------------
;;; ACCESSOR / READER / WRITER METHOD CREATION
;;;
;;; The following code creates optimized and unoptimized versions of the
;;; slot accessors defined for a class. They are designed so that at least
;;; some varieties work at boot time.
;;;
(defun safe-slot-definition-location (slotd &optional default)
(declare (ignore default))
(cond ((listp slotd)
(error "List instead of a slot definition object"))
(t
(slot-value slotd 'location))))
(defun std-class-sealed-accessors (index)
(declare (si::c-local)
(fixnum index))
(values #'(lambda (self)
(declare (optimize (safety 0) (speed 3) (debug 0))
(standard-object self))
(ensure-up-to-date-instance self)
(safe-instance-ref self index))
#'(lambda (value self)
(declare (optimize (safety 0) (speed 3) (debug 0))
(standard-object self))
(ensure-up-to-date-instance self)
(si:instance-set self index value))))
(defun std-class-accessors (slot-name)
(declare (si::c-local))
;; The following are very slow. We do not optimize for the slot position.
(values #'(lambda (self)
(slot-value self slot-name))
#'(lambda (value self)
(setf (slot-value self slot-name) value))))
(defun safe-add-method (name method)
;; Adds a method to a function which might have been previously defined
;; as non-generic, without breaking the function
(cond ((or *clos-booted*
(not (fboundp name))
(si::instancep (fdefinition name)))
(add-method (ensure-generic-function name) method))
(t
(let* ((alt-name '#:foo)
(gf (ensure-generic-function alt-name)))
(add-method gf method)
(setf (generic-function-name gf) name)
(setf (fdefinition name) gf)
(fmakunbound alt-name)))))
(defun std-class-generate-accessors (standard-class &optional (optimizable t))
;;
;; The accessors are closures, which are generated every time the
;; slots of the class change. The accessors are safe: they check that
;; the slot is bound after retreiving the value, and they may take
;; the liberty of using SI:INSTANCE-REF because they know the class of
;; the instance.
;;
(dolist (slotd (slot-value standard-class 'direct-slots))
(with-slots ((name name) (allocation allocation) (location location)
(readers readers) (writers writers))
slotd
;; When a class is of a specified class in the MOP (such as
;; STANDARD-CLASS), then the user may not write any method
;; around SLOT-VALUE-USING-CLASS. This allows us to write
;; optimized versions of the accessors.
(unless (member (slot-value standard-class 'name)
'(standard-class
funcallable-standard-class
structure-class))
(setf optimizable nil))
(multiple-value-bind (reader writer)
(cond ((and optimizable
(eq allocation :instance)
;; This is an extension by ECL in which a direct slot
;; definition specifies the location of a slot. It
;; only happens for sealed classes.
(typep location 'fixnum))
(std-class-sealed-accessors location))
(t
(std-class-accessors name)))
(let* ((options (list :slot-definition slotd))
(reader-args (list* :function reader
:generic-function nil
:qualifiers nil
:lambda-list '(object)
:specializers `(,standard-class)
options))
(reader-class (if (boundp '*early-methods*)
'standard-reader-method
(apply #'reader-method-class standard-class slotd
reader-args)))
(writer-args (list* :function writer
:generic-function nil
:qualifiers nil
:lambda-list '(value object)
:specializers `(,(find-class t) ,standard-class)
options))
(writer-class (if (boundp '*early-methods*)
'standard-writer-method
(apply #'writer-method-class standard-class slotd
writer-args))))
(dolist (fname readers)
(let ((method (make-method reader-class nil `(,standard-class) '(self)
(wrapped-method-function reader)
options)))
(safe-add-method fname method)
;; This is redundant, but we need it at boot time because
;; the early MAKE-METHOD does not use the options field.
(unless *clos-booted*
(setf (slot-value method 'slot-definition) slotd))))
(dolist (fname writers)
(let ((method (make-method writer-class nil
`(,(find-class t) ,standard-class) '(value self)
(wrapped-method-function writer)
options)))
(safe-add-method fname method)
;; This is redundant, but we need it at boot time because
;; the early MAKE-METHOD does not use the options field.
(unless *clos-booted*
(setf (slot-value method 'slot-definition) slotd)))))))))
(defun reader-closure (index)
(declare (si::c-local))
(lambda (object) (si::instance-ref object index)))
(defun writer-closure (index)
(declare (si::c-local))
(lambda (value object) (si::instance-set object index value)))
(labels ((generate-accessors (class)
(declare (optimize speed (safety 0)))
(if (typep class 'std-class)
(std-class-generate-accessors class t)
(loop for slotd in (slot-value class 'slots)
for index = (slot-value slotd 'location)
do (loop for reader in (slot-value slotd 'readers)
do (setf (fdefinition reader) (reader-closure index)))
do (loop for writer in (slot-value slotd 'writers)
do (setf (fdefinition writer) (writer-closure index)))))
(mapc #'generate-accessors (slot-value class 'direct-subclasses))))
(generate-accessors +the-t-class+))