(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*)
-(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
(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."
(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 ((*initfunctions-for-this-defclass* ())
+ (*readers-for-this-defclass* ()) ;Truly a crock, but we got
+ (*writers-for-this-defclass* ())) ;to have it to live nicely.
(let ((canonical-slots
- (mapcar #'(lambda (spec)
- (canonicalize-slot-specification name spec))
+ (mapcar (lambda (spec)
+ (canonicalize-slot-specification name spec))
slots))
(other-initargs
- (mapcar #'(lambda (option)
- (canonicalize-defclass-option name option))
+ (mapcar (lambda (option)
+ (canonicalize-defclass-option name option))
options))
- ;; DEFSTRUCT-P should be true, if the class is defined with a
- ;; metaclass STRUCTURE-CLASS, such that a DEFSTRUCT is compiled
- ;; for the class.
+ ;; 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
mclass
*the-class-structure-class*))))))
(let ((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)))))))
+ `(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*)
+ (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
- (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
- slots
- 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
- ;; 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".
- ,(when (and
- ;; But it's not so important to get rid of
- ;; "not defined yet" warnings during
- ;; bootstrapping, and machinery like
- ;; INFORM-TYPE-SYSTEM-ABOUT-STD-CLASS
- ;; mightn't be defined yet. So punt then.
- (eq *boot-state* 'complete)
- ;; And although we know enough about
- ;; STANDARD-CLASS, and ANSI imposes enough
- ;; restrictions on the user overloading its
- ;; methods, that (1) we can shortcut the
- ;; method dispatch and do an ordinary
- ;; function call, and (2) be sure we're getting
- ;; it right even when we do it at compile
- ;; time; we don't in general know how to do
- ;; that for other classes. So punt then too.
- (eq metaclass 'standard-class))
- `(eval-when (:compile-toplevel)
- ;; we only need :COMPILE-TOPLEVEL here, because this
- ;; should happen in the compile-time environment
- ;; only.
- ;; Later, INFORM-TYPE-SYSTEM-ABOUT-STD-CLASS is
- ;; called by way of LOAD-DEFCLASS (calling
- ;; ENSURE-CLASS-USING-CLASS) to establish the 'real'
- ;; type predicate.
- (inform-type-system-about-std-class ',name)))
- ,defclass-form))))))))
+ (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
+ ;; 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))))
(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
(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*