convert.c (convert_to_integer): Issue an error on conversions to incomplete types.

	* convert.c (convert_to_integer): Issue an error on conversions to
	incomplete types.

From-SVN: r22102

gcc/ChangeLog

+Sun Aug 30 16:05:45 1998  Mark Mitchell  <mark@markmitchell.com>
+
+	* convert.c (convert_to_integer): Issue an error on conversions to
+	incomplete types.
+
 Sun Aug 30 16:47:20 1998  Martin von Lvwis  <loewis@informatik.hu-berlin.de>
 
 	* Makefile.in: Add lang_tree_files and gencheck.h.

gcc/convert.c

@@ -121,6 +121,14 @@ convert_to_integer (type, expr)
   int inprec = TYPE_PRECISION (intype);
   int outprec = TYPE_PRECISION (type);
 
+  /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
+     be.  Consider `enum E = { a, b = (enum E) 3 };'.  */
+  if (!TYPE_SIZE (type))
+    {
+      error ("conversion to incomplete type");
+      return error_mark_node;
+    }
+
   switch (TREE_CODE (intype))
     {
     case POINTER_TYPE: