X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/d83a91c663ced211bb7e4509f800859c3fa086e9..c2438e62e7c3cf1b7006522cef61e8c6f797600b:/src/class-output.lisp

diff --git a/src/class-output.lisp b/src/class-output.lisp
index 2ab6363..eb5bc26 100644
--- a/src/class-output.lisp
+++ b/src/class-output.lisp
@@ -296,11 +296,23 @@
 			 struct ~A {~%"
 		 (vtable-struct-tag chain-tail chain-head)))
 	((class :vtable chain-head :end)
-	 (format stream "};~2%"))))
+	 (format stream "};~2%")
+	 (format stream "/* Union of equivalent superclass vtables. */~@
+			 union ~A {~@
+			 ~:{  struct ~A ~A;~%~}~
+			 };~2%"
+		 (vtable-union-tag chain-tail chain-head)
+
+		 ;; As for the ichain union, make sure the most specific
+		 ;; class is first.
+		 (mapcar (lambda (super)
+			   (list (vtable-struct-tag super chain-head)
+				 (sod-class-nickname super)))
+			 (sod-class-chain chain-tail))))))
     (sequence-output (stream sequencer)
       ((class :vtable-externs)
-       (format stream "~@<extern const struct ~A ~2I~_~A__vtable_~A;~:>~%"
-	       (vtable-struct-tag chain-tail chain-head)
+       (format stream "~@<extern const union ~A ~2I~_~A__vtable_~A;~:>~%"
+	       (vtable-union-tag chain-tail chain-head)
 	       class (sod-class-nickname chain-head))))))
 
 (defmethod hook-output progn ((vtmsgs vtmsgs) (reason (eql :h)) sequencer)
@@ -470,12 +482,12 @@ const struct ~A ~A__classobj = {~%"
 		   (class :vtables :end))
       ((class :vtable chain-head :start)
        (format stream "/* Vtable for ~A chain. */~@
-		       const struct ~A ~A = {~%"
+		       const union ~A ~A = { {~%"
 	       chain-head
-	       (vtable-struct-tag chain-tail chain-head)
+	       (vtable-union-tag chain-tail chain-head)
 	       (vtable-name class chain-head)))
       ((class :vtable chain-head :end)
-       (format stream "};~2%")))))
+       (format stream "} };~2%")))))
 
 (defmethod hook-output progn ((cptr class-pointer)
 			      (reason (eql :c))
@@ -592,8 +604,10 @@ const struct ~A ~A__classobj = {~%"
 		   (*instance-class* :object chain-head :vtable)
 		   (*instance-class* :object chain-head :ichain :end))
       ((*instance-class* :object chain-head :vtable)
-       (format stream "      &~A__vtable_~A,~%"
-	       class (sod-class-nickname chain-head))))))
+       (format stream "      /* ~17@A = */ &~A.~A,~%"
+	       "_vt"
+	       (vtable-name class chain-head)
+	       (sod-class-nickname chain-tail))))))
 
 (defgeneric find-class-initializer (slot class)
   (:method ((slot effective-slot) (class sod-class))