re PR c++/16021 (Tests for container swap specialisations FAIL in debug mode)

        PR c++/16021
        * name-lookup.c (parse_using_directive): Require strong using to
        name a nested namespace.

From-SVN: r110282

gcc/cp/ChangeLog

+2006-01-26  Jason Merrill  <jason@redhat.com>
+
+	PR c++/16021
+	* name-lookup.c (parse_using_directive): Require strong using to
+	name a nested namespace.
+
 2006-01-25  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
 
 	Revert:

gcc/cp/name-lookup.c

@@ -3295,9 +3295,14 @@ parse_using_directive (tree namespace, tree attribs)
 	  if (!toplevel_bindings_p ())
 	    error ("strong using only meaningful at namespace scope");
 	  else if (namespace != error_mark_node)
-	    DECL_NAMESPACE_ASSOCIATIONS (namespace)
-	      = tree_cons (current_namespace, 0,
-			   DECL_NAMESPACE_ASSOCIATIONS (namespace));
+	    {
+	      if (!is_ancestor (current_namespace, namespace))
+		error ("current namespace %qD does not enclose strongly used namespace %qD",
+		       current_namespace, namespace);
+	      DECL_NAMESPACE_ASSOCIATIONS (namespace)
+		= tree_cons (current_namespace, 0,
+			     DECL_NAMESPACE_ASSOCIATIONS (namespace));
+	    }
 	}
       else
 	warning (OPT_Wattributes, "%qD attribute directive ignored", name);

gcc/testsuite/g++.dg/lookup/strong-using-1.C

@@ -2,10 +2,10 @@
 
 // { dg-do compile }
 
-namespace foo {
-  template <class T> void swap(T, T);
-}
 namespace fool {
+  namespace foo {
+    template <class T> void swap(T, T);
+  }
   using namespace foo __attribute__((strong));
   template <class T> void swap(T);
 }

gcc/testsuite/g++.dg/lookup/strong-using-2.C

@@ -2,16 +2,16 @@
 
 // { dg-do compile }
 
-namespace foo_impl {
-  class T; // { dg-error "T" "" }
-}
-namespace bar_impl {
-  class T; // { dg-error "T" "" }
-}
 namespace foo {
+  namespace foo_impl {
+    class T; // { dg-error "T" "" }
+  }
   using namespace foo_impl __attribute__((strong));
 }
 namespace bar {
+  namespace bar_impl {
+    class T; // { dg-error "T" "" }
+  }
   using namespace bar_impl __attribute__((strong));
   using namespace foo;
 }

gcc/testsuite/g++.dg/lookup/strong-using-3.C

@@ -2,10 +2,10 @@
 
 // { dg-do compile }
 
-namespace foo {
-  template <class T> void f(T, T);
-}
 namespace bar {
+  namespace foo {
+    template <class T> void f(T, T);
+  }
   using namespace foo __attribute__((strong));
   template <class T> void f(T);
 }