X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/456578422ddec347a6666b5a42559d4554f8c296..9761db0da830385bcc0fca81f56f24536a46aeda:/src/class-finalize-impl.lisp

diff --git a/src/class-finalize-impl.lisp b/src/class-finalize-impl.lisp
index 9e75412..36d56e0 100644
--- a/src/class-finalize-impl.lisp
+++ b/src/class-finalize-impl.lisp
@@ -7,7 +7,7 @@
 
 ;;;----- Licensing notice ---------------------------------------------------
 ;;;
-;;; This file is part of the Sensble Object Design, an object system for C.
+;;; This file is part of the Sensible Object Design, an object system for C.
 ;;;
 ;;; SOD is free software; you can redistribute it and/or modify
 ;;; it under the terms of the GNU General Public License as published by
@@ -100,6 +100,7 @@
 
 ;;; Linearization functions.
 
+(export 'clos-cpl)
 (defun clos-cpl (class)
   "Compute the class precedence list of CLASS using CLOS linearization rules.
 
@@ -122,6 +123,7 @@
 			 (superclasses class))
 		 :pick #'clos-tiebreaker)))
 
+(export 'dylan-cpl)
 (defun dylan-cpl (class)
   "Compute the class precedence list of CLASS using Dylan linearization
    rules.
@@ -145,6 +147,7 @@
 		       (mapcar #'sod-class-precedence-list direct-supers))
 		 :pick #'clos-tiebreaker)))
 
+(export 'c3-cpl)
 (defun c3-cpl (class)
   "Compute the class precedence list of CLASS using C3 linearization rules.
 
@@ -164,6 +167,7 @@
 			 (declare (ignore so-far))
 			 (c3-tiebreaker candidates cpls)))))
 
+(export 'flavors-cpl)
 (defun flavors-cpl (class)
   "Compute the class precedence list of CLASS using Flavors linearization
    rules.
@@ -186,6 +190,7 @@
       (walk class)
       (nreverse done))))
 
+(export 'python-cpl)
 (defun python-cpl (class)
   "Compute the class precedence list of CLASS using the documented Python 2.2
    linearization rules.
@@ -205,6 +210,7 @@
       (walk class)
       (delete-duplicates (nreverse done)))))
 
+(export 'l*loops-cpl)
 (defun l*loops-cpl (class)
   "Compute the class precedence list of CLASS using L*LOOPS linearization
    rules.
@@ -270,6 +276,35 @@
 					 (cdr class-precedence-list)))))))))
 
 ;;;--------------------------------------------------------------------------
+;;; Metaclasses.
+
+(defun maximum (items order what)
+  "Return a maximum item according to the non-strict partial ORDER."
+  (reduce (lambda (best this)
+	    (cond ((funcall order best this) best)
+		  ((funcall order this best) this)
+		  (t (error "Unable to choose best ~A." what))))
+	  items))
+
+(defmethod guess-metaclass ((class sod-class))
+  "Default metaclass-guessing function for classes.
+
+   Return the most specific metaclass of any of the CLASS's direct
+   superclasses."
+
+  ;; During bootstrapping, our superclasses might not have their own
+  ;; metaclasses resolved yet.  If we find this, then throw `bootstrapping'
+  ;; so that `shared-initialize' on `sod-class' can catch it (or as a shot
+  ;; across the bows of anyone else who calls us).
+  (maximum (mapcar (lambda (super)
+		     (if (slot-boundp super 'metaclass)
+			 (slot-value super 'metaclass)
+			 (throw 'bootstrapping nil)))
+		   (sod-class-direct-superclasses class))
+	   #'sod-subclass-p
+	   (format nil "metaclass for `~A'" class)))
+
+;;;--------------------------------------------------------------------------
 ;;; Sanity checking.
 
 (defmethod check-sod-class ((class sod-class))
@@ -344,7 +379,12 @@
       ((nil)
 
        ;; If this fails, mark the class as a loss.
-       (setf (sod-class-state class) :broken)
+       (setf (slot-value class 'state) :broken)
+
+       ;; Set up the metaclass if it's not been set already.  This is delayed
+       ;; to give bootstrapping a chance to set up metaclass and superclass
+       ;; circularities.
+       (default-slot (class 'metaclass) (guess-metaclass class))
 
        ;; Finalize all of the superclasses.  There's some special pleading
        ;; here to make bootstrapping work: we don't try to finalize the
@@ -360,7 +400,7 @@
 	   (finalize-sod-class metaclass)))
 
        ;; Stash the class's type.
-       (setf (sod-class-type class)
+       (setf (slot-value class '%type)
 	     (make-class-type (sod-class-name class)))
 
        ;; Clobber the lists of items if they've not been set.
@@ -382,7 +422,7 @@
 	 (setf (values chain-head chain chains) (compute-chains class)))
 
        ;; Done.
-       (setf (sod-class-state class) :finalized)
+       (setf (slot-value class 'state) :finalized)
        t)
 
       (:broken
@@ -391,4 +431,18 @@
       (:finalized
        t))))
 
+(flet ((check-class-is-finalized (class)
+	 (unless (eq (sod-class-state class) :finalized)
+	   (error "Class ~S is not finalized" class))))
+  (macrolet ((define-layout-slot (slot (class) &body body)
+	       `(define-on-demand-slot sod-class ,slot (,class)
+		  (check-class-is-finalized ,class)
+		  ,@body)))
+    (define-layout-slot %ilayout (class)
+      (compute-ilayout class))
+    (define-layout-slot effective-methods (class)
+      (compute-effective-methods class))
+    (define-layout-slot vtables (class)
+      (compute-vtables class))))
+
 ;;;----- That's all, folks --------------------------------------------------