re PR c++/46220 (Error: invalid covariant return type generated for incomplete…

re PR c++/46220 (Error: invalid covariant return type generated for incomplete class type and different qualifer)

	PR c++/46220
	* search.c (check_final_overrider): Allow pointer to same incomplete
	class type with different cv-quals.

From-SVN: r170676

gcc/cp/ChangeLog

+2011-03-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/46220
+	* search.c (check_final_overrider): Allow pointer to same incomplete
+	class type with different cv-quals.
+
 2011-03-03  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/47974

gcc/cp/search.c

@@ -1835,11 +1835,17 @@ check_final_overrider (tree overrider, tree basefn)
 
       if (CLASS_TYPE_P (base_return) && CLASS_TYPE_P (over_return))
 	{
-	  tree binfo = lookup_base (over_return, base_return,
-				    ba_check | ba_quiet, NULL);
+	  /* Strictly speaking, the standard requires the return type to be
+	     complete even if it only differs in cv-quals, but that seems
+	     like a bug in the wording.  */
+	  if (!same_type_ignoring_top_level_qualifiers_p (base_return, over_return))
+	    {
+	      tree binfo = lookup_base (over_return, base_return,
+					ba_check | ba_quiet, NULL);
 
-	  if (!binfo)
-	    fail = 1;
+	      if (!binfo)
+		fail = 1;
+	    }
 	}
       else if (!pedantic
 	       && can_convert (TREE_TYPE (base_type), TREE_TYPE (over_type)))

gcc/testsuite/ChangeLog

+2011-03-04  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/inherit/covariant19.C: New.
+
 2011-03-04  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/47968

gcc/testsuite/g++.dg/inherit/covariant19.C

+// PR c++/46220
+// According to the letter of the standard this is invalid,
+// but that seems like a bug.
+
+class Baz;
+class Foo {
+public:
+    virtual const Baz* getBaz() = 0;
+};
+class Bar : public Foo {
+public:
+    Baz* getBaz();
+};
+