X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/67678b0be4da2701655d3d52db205d815f0687ea..267aeb614f1d2bdbd92019abb126a52de642ba21:/src/class-layout-impl.lisp

diff --git a/src/class-layout-impl.lisp b/src/class-layout-impl.lisp
index e93f401..1794e5a 100644
--- a/src/class-layout-impl.lisp
+++ b/src/class-layout-impl.lisp
@@ -267,17 +267,19 @@
     ((class sod-class) (chain-head sod-class)
      (metaclass sod-class) (meta-chain-head sod-class))
 
-  ;; Slightly tricky.  We don't necessarily want a pointer to the metaclass,
-  ;; but to its most specific subclass on the given chain.  Fortunately, CL
-  ;; is good at this game.
-  (let* ((meta-chains (sod-class-chains metaclass))
-	 (meta-chain-tails (mapcar #'car meta-chains))
-	 (meta-chain-tail (find meta-chain-head meta-chain-tails
-				:key #'sod-class-chain-head)))
+  ;; Rather tricky.  This is a class pointer on a vtable for the CHAIN-HEAD
+  ;; chain, pointing into the META-CHAIN-HEAD chain of the metaclass.  We
+  ;; need to produce a pointer to the most specific superclass of the
+  ;; metaclass on the right chain that is a superclass of the metaclass of
+  ;; the most specific class in the superclass chain headed by CHAIN-HEAD.
+  (flet ((chain-tail (class head)
+	   (find head (mapcar #'car (sod-class-chains class))
+		 :key #'sod-class-chain-head)))
     (make-instance 'class-pointer
-		   :class class
-		   :chain-head chain-head
-		   :metaclass meta-chain-tail
+		   :class class :chain-head chain-head
+		   :metaclass (chain-tail (sod-class-metaclass
+					   (chain-tail class chain-head))
+					  meta-chain-head)
 		   :meta-chain-head meta-chain-head)))
 
 ;;; base-offset
@@ -328,7 +330,8 @@
 
   ;; If this class introduces new metaclass chains, then emit pointers to
   ;; them.
-  (let* ((metasuper (sod-class-metaclass super))
+  (let* ((metaclass (sod-class-metaclass class))
+	 (metasuper (sod-class-metaclass super))
 	 (metasuper-chains (sod-class-chains metasuper))
 	 (metasuper-chain-heads (mapcar (lambda (chain)
 					  (sod-class-chain-head (car chain)))
@@ -337,7 +340,7 @@
       (unless (member metasuper-chain-head *done-metaclass-chains*)
 	(funcall emit (make-class-pointer class
 					  chain-head
-					  metasuper
+					  metaclass
 					  metasuper-chain-head))
 	(push metasuper-chain-head *done-metaclass-chains*))))