(in-package "SB-PCL")
\f
+;;;; DEFCLASS macro and close personal friends
+
+;;; ANSI says (Macro DEFCLASS, section 7.7) that DEFCLASS, if it
+;;; "appears as a top level form, the compiler must make the class
+;;; name be recognized as a valid type name in subsequent declarations
+;;; (as for deftype) and be recognized as a valid class name for
+;;; defmethod parameter specializers and for use as the :metaclass
+;;; option of a subsequent defclass."
+(defun preinform-compiler-about-class-type (name)
+ ;; Unless the type system already has an actual type attached to
+ ;; NAME (in which case (1) writing a placeholder value over that
+ ;; actual type as a compile-time side-effect would probably be a bad
+ ;; idea and (2) anyway we don't need to modify it in order to make
+ ;; NAME be recognized as a valid type name)
+ (unless (info :type :kind name)
+ ;; Tell the compiler to expect a class with the given NAME, by
+ ;; writing a kind of minimal placeholder type information. This
+ ;; placeholder will be overwritten later when the class is defined.
+ (setf (info :type :kind name) :forthcoming-defclass-type))
+ (values))
+
+;;; state for the current DEFCLASS expansion
+(defvar *initfunctions-for-this-defclass*)
+(defvar *readers-for-this-defclass*)
+(defvar *writers-for-this-defclass*)
+(defvar *slot-names-for-this-defclass*)
-(defun make-progn (&rest forms)
- (let ((progn-form nil))
- (labels ((collect-forms (forms)
- (unless (null forms)
- (collect-forms (cdr forms))
- (if (and (listp (car forms))
- (eq (caar forms) 'progn))
- (collect-forms (cdar forms))
- (push (car forms) progn-form)))))
- (collect-forms forms)
- (cons 'progn progn-form))))
-\f
;;; Like the DEFMETHOD macro, the expansion of the DEFCLASS macro is
;;; fixed. DEFCLASS always expands into a call to LOAD-DEFCLASS. Until
;;; the meta-braid is set up, LOAD-DEFCLASS has a special definition
;;;
;;; After the metabraid has been setup, and the protocol for defining
;;; classes has been defined, the real definition of LOAD-DEFCLASS is
-;;; installed by the file defclass.lisp
-(defmacro defclass (name direct-superclasses direct-slots &rest options)
- (expand-defclass name direct-superclasses direct-slots options))
-
-(defun expand-defclass (name supers slots options)
- (setq supers (copy-tree supers)
- slots (copy-tree slots)
- options (copy-tree options))
- (let ((metaclass 'standard-class))
- (dolist (option options)
- (if (not (listp option))
+;;; installed by the file std-class.lisp
+(defmacro defclass (name %direct-superclasses %direct-slots &rest %options)
+ (let ((supers (copy-tree %direct-superclasses))
+ (slots (copy-tree %direct-slots))
+ (options (copy-tree %options)))
+ (let ((metaclass 'standard-class))
+ (dolist (option options)
+ (if (not (listp option))
(error "~S is not a legal defclass option." option)
- (when (eq (car option) ':metaclass)
+ (when (eq (car option) :metaclass)
(unless (legal-class-name-p (cadr option))
(error "The value of the :metaclass option (~S) is not a~%~
legal class name."
(cadr option)))
- (setq metaclass
- (case (cadr option)
- (cl:standard-class 'standard-class)
- (cl:structure-class 'structure-class)
- (t (cadr option))))
+ (setq metaclass (cadr option))
(setf options (remove option options))
(return t))))
- (let ((*initfunctions* ())
- (*readers* ()) ;Truly a crock, but we got
- (*writers* ())) ;to have it to live nicely.
- (declare (special *initfunctions* *readers* *writers*))
- (let ((canonical-slots
- (mapcar #'(lambda (spec)
+ (let ((*initfunctions-for-this-defclass* ())
+ (*readers-for-this-defclass* ()) ;Truly a crock, but we got
+ (*writers-for-this-defclass* ()) ;to have it to live nicely.
+ (*slot-names-for-this-defclass* ()))
+ (let ((canonical-slots
+ (mapcar (lambda (spec)
(canonicalize-slot-specification name spec))
- slots))
- (other-initargs
- (mapcar #'(lambda (option)
+ slots))
+ (other-initargs
+ (mapcar (lambda (option)
(canonicalize-defclass-option name option))
- options))
- (defstruct-p (and (eq *boot-state* 'complete)
- (let ((mclass (find-class metaclass nil)))
- (and mclass
- (*subtypep
- mclass
- *the-class-structure-class*))))))
- (let ((defclass-form
+ options))
+ ;; DEFSTRUCT-P should be true if the class is defined
+ ;; with a metaclass STRUCTURE-CLASS, so that a DEFSTRUCT
+ ;; is compiled for the class.
+ (defstruct-p (and (eq *boot-state* 'complete)
+ (let ((mclass (find-class metaclass nil)))
+ (and mclass
+ (*subtypep
+ mclass
+ *the-class-structure-class*))))))
+ (let ((defclass-form
+ `(progn
+ ,@(mapcar (lambda (x)
+ `(declaim (ftype (function (t) t) ,x)))
+ *readers-for-this-defclass*)
+ ,@(mapcar (lambda (x)
+ `(declaim (ftype (function (t t) t) ,x)))
+ *writers-for-this-defclass*)
+ ,@(mapcar (lambda (x)
+ `(declaim (ftype (function (t) t)
+ ,(slot-reader-name x)
+ ,(slot-boundp-name x))
+ (ftype (function (t t) t)
+ ,(slot-writer-name x))))
+ *slot-names-for-this-defclass*)
+ (let ,(mapcar #'cdr *initfunctions-for-this-defclass*)
+ (load-defclass ',name
+ ',metaclass
+ ',supers
+ (list ,@canonical-slots)
+ (list ,@(apply #'append
+ (when defstruct-p
+ '(:from-defclass-p t))
+ other-initargs)))))))
+ (if defstruct-p
+ (progn
+ ;; FIXME: (YUK!) Why do we do this? Because in order
+ ;; to make the defstruct form, we need to know what
+ ;; the accessors for the slots are, so we need
+ ;; already to have hooked into the CLOS machinery.
+ ;;
+ ;; There may be a better way to do this: it would
+ ;; involve knowing enough about PCL to ask "what
+ ;; will my slot names and accessors be"; failing
+ ;; this, we currently just evaluate the whole
+ ;; kaboodle, and then use CLASS-DIRECT-SLOTS. --
+ ;; CSR, 2002-06-07
+ (eval defclass-form)
+ (let* ((include (or (and supers
+ (fix-super (car supers)))
+ (and (not (eq name 'structure-object))
+ *the-class-structure-object*)))
+ (defstruct-form (make-structure-class-defstruct-form
+ name (class-direct-slots (find-class name)) include)))
+ `(progn
+ (eval-when (:compile-toplevel :load-toplevel :execute)
+ ,defstruct-form) ; really compile the defstruct-form
+ (eval-when (:compile-toplevel :load-toplevel :execute)
+ ,defclass-form))))
`(progn
- ,@(mapcar (lambda (x)
- `(declaim (ftype (function (t) t) ,x)))
- *readers*)
- ,@(mapcar (lambda (x)
- `(declaim (ftype (function (t t) t) ,x)))
- *writers*)
- (let ,(mapcar #'cdr *initfunctions*)
- (load-defclass ',name
- ',metaclass
- ',supers
- (list ,@canonical-slots)
- (list ,@(apply #'append
- (when defstruct-p
- '(:from-defclass-p t))
- other-initargs)))))))
- ;; FIXME: The way that we do things like (EVAL DEFCLASS-FORM)
- ;; here is un-ANSI-Common-Lisp-y and leads to problems
- ;; (like DEFUN for the type predicate being called more than
- ;; once when we do DEFCLASS at the interpreter prompt),
- ;; causing bogus style warnings. It would be better to
- ;; rewrite this so that the macroexpansion looks like e.g.
- ;; (PROGN
- ;; (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
- ;; (FROB1 ..))
- ;; (EVAL-WHEN (:LOAD-TOPLEVEL :EXECUTE)
- ;; (FROB2 ..)))
- (if defstruct-p
- (progn
- (eval defclass-form) ; Define the class now, so that..
- `(progn ; ..the defstruct can be compiled.
- ,(class-defstruct-form (find-class name))
- ,defclass-form))
- (progn
- (when (eq *boot-state* 'complete)
- ;; FIXME: MNA (on sbcl-devel 2001-05-30) reported
- ;; (if I understand correctly -- WHN) that this call
- ;; is directly responsible for defining
- ;; class-predicates which always return
- ;; CONSTANTLY-NIL in the compile-time environment,
- ;; and is indirectly responsible for bogus warnings
- ;; about redefinitions when making definitions in
- ;; the interpreter. I didn't like his fix (deleting
- ;; the call) since I think the type system *should*
- ;; be informed about class definitions here. And I'm
- ;; not eager to look too deeply into this sort of
- ;; done-too-many-times-in-the-interpreter problem
- ;; right now, since it should be easier to make a
- ;; clean fix when EVAL-WHEN is made more ANSI (as
- ;; per the IR1 section in the BUGS file). But
- ;; at some point this should be cleaned up.
- (inform-type-system-about-std-class name))
- defclass-form)))))))
+ ;; By telling the type system at compile time about
+ ;; the existence of a class named NAME, we can avoid
+ ;; various bogus warnings about "type isn't defined yet"
+ ;; for code elsewhere in the same file which uses
+ ;; the name of the type.
+ ;;
+ ;; We only need to do this at compile time, because
+ ;; at load and execute time we write the actual
+ ;; full-blown class, so the "a class of this name is
+ ;; coming" note we write here would be irrelevant.
+ (eval-when (:compile-toplevel)
+ (preinform-compiler-about-class-type ',name))
+ ,defclass-form))))))))
(defun make-initfunction (initform)
- (declare (special *initfunctions*))
(cond ((or (eq initform t)
(equal initform ''t))
'(function constantly-t))
(equal initform ''0))
'(function constantly-0))
(t
- (let ((entry (assoc initform *initfunctions* :test #'equal)))
+ (let ((entry (assoc initform *initfunctions-for-this-defclass*
+ :test #'equal)))
(unless entry
(setq entry (list initform
(gensym)
`(function (lambda () ,initform))))
- (push entry *initfunctions*))
+ (push entry *initfunctions-for-this-defclass*))
(cadr entry)))))
(defun canonicalize-slot-specification (class-name spec)
- (declare (special *readers* *writers*))
(cond ((and (symbolp spec)
(not (keywordp spec))
(not (memq spec '(t nil))))
+ (push spec *slot-names-for-this-defclass*)
`'(:name ,spec))
((not (consp spec))
(error "~S is not a legal slot specification." spec))
((null (cdr spec))
+ (push (car spec) *slot-names-for-this-defclass*)
`'(:name ,(car spec)))
((null (cddr spec))
(error "In DEFCLASS ~S, the slot specification ~S is obsolete.~%~
(initargs ())
(unsupplied (list nil))
(initform (getf spec :initform unsupplied)))
+ (push name *slot-names-for-this-defclass*)
(doplist (key val) spec
(case key
(:accessor (push val readers)
(loop (unless (remf spec :reader) (return)))
(loop (unless (remf spec :writer) (return)))
(loop (unless (remf spec :initarg) (return)))
- (setq *writers* (append writers *writers*))
- (setq *readers* (append readers *readers*))
+ (setq *writers-for-this-defclass*
+ (append writers *writers-for-this-defclass*))
+ (setq *readers-for-this-defclass*
+ (append readers *readers-for-this-defclass*))
(setq spec `(:name ',name
:readers ',readers
:writers ',writers
(if (eq initform unsupplied)
`(list* ,@spec)
`(list* :initfunction ,(make-initfunction initform) ,@spec))))))
-
+
(defun canonicalize-defclass-option (class-name option)
(declare (ignore class-name))
(case (car option)
(setq key (pop tail)
val (pop tail))
(push ``(,',key ,,(make-initfunction val) ,',val) canonical))
- `(':direct-default-initargs (list ,@(nreverse canonical))))))
+ `(:direct-default-initargs (list ,@(nreverse canonical))))))
(:documentation
`(',(car option) ',(cadr option)))
(otherwise
`(',(car option) ',(cdr option)))))
\f
-;;; This is the early definition of load-defclass. It just collects up
-;;; all the class definitions in a list. Later, in the file
-;;; braid1.lisp, these are actually defined.
+;;; This is the early definition of LOAD-DEFCLASS. It just collects up
+;;; all the class definitions in a list. Later, in braid1.lisp, these
+;;; are actually defined.
;;; Each entry in *EARLY-CLASS-DEFINITIONS* is an EARLY-CLASS-DEFINITION.
(defparameter *early-class-definitions* ())
(values (early-collect-slots cpl)
cpl
(early-collect-default-initargs cpl)
- (gathering1 (collecting)
+ (let (collect)
(dolist (definition *early-class-definitions*)
(when (memq class-name (ecd-superclass-names definition))
- (gather1 (ecd-class-name definition))))))))
+ (push (ecd-class-name definition) collect)))
+ (nreverse collect)))))
(defun early-collect-slots (cpl)
(let* ((definitions (mapcar #'early-class-definition cpl))
(setq supers (copy-tree supers)
canonical-slots (copy-tree canonical-slots)
canonical-options (copy-tree canonical-options))
- (when (eq metaclass 'standard-class)
- (inform-type-system-about-std-class name))
(let ((ecd
(make-early-class-definition name
- *load-truename*
+ *load-pathname*
metaclass
supers
canonical-slots