re PR c++/14821 (Duplicate namespace alias declaration should not conflict)

	PR c++/14821
	* name-lookup.c (supplement_binding): Allow redefinitions of
	namespace aliases.

	PR c++/14883
	* parser.c (cp_parser_template_argument): Robustify.

	PR c++/14821
	* g++.dg/other/ns1.C: New test.

	PR c++/14883
	* g++.dg/template/invalid1.C: New test.

From-SVN: r82170

gcc/cp/ChangeLog

+2004-05-23  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/14821
+	* name-lookup.c (supplement_binding): Allow redefinitions of
+	namespace aliases.
+
+	PR c++/14883
+	* parser.c (cp_parser_template_argument): Robustify.
+
 2004-05-23  Gabriel Dos Reis  <gdr@integrable-solutions.net>
 
 	* class.c (alter_access): Use %E format specifier to print an

gcc/cp/name-lookup.c

@@ -503,11 +503,22 @@ supplement_binding (cxx_binding *binding, tree decl)
       duplicate_decls (decl, binding->value);
       ok = false;
     }
+  else if (TREE_CODE (decl) == NAMESPACE_DECL
+	   && TREE_CODE (bval) == NAMESPACE_DECL
+	   && DECL_NAMESPACE_ALIAS (decl)
+	   && DECL_NAMESPACE_ALIAS (bval)
+	   && ORIGINAL_NAMESPACE (bval) == ORIGINAL_NAMESPACE (decl))
+    /* [namespace.alias]
+       
+      In a declarative region, a namespace-alias-definition can be
+      used to redefine a namespace-alias declared in that declarative
+      region to refer only to the namespace to which it already
+      refers.  */
+    ok = false;
   else
     {
       error ("declaration of `%#D'", decl);
-      cp_error_at ("conflicts with previous declaration `%#D'",
-		   binding->value);
+      cp_error_at ("conflicts with previous declaration `%#D'", bval);
       ok = false;
     }
 

gcc/cp/parser.c

@@ -8417,12 +8417,16 @@ cp_parser_template_argument (cp_parser* parser)
     cp_parser_error (parser, "expected template-argument");
   if (!cp_parser_error_occurred (parser))
     {
-      /* Figure out what is being referred to.  */
-      argument = cp_parser_lookup_name (parser, argument,
-					/*is_type=*/false,
-					/*is_template=*/template_p,
-					/*is_namespace=*/false,
-					/*check_dependency=*/true);
+      /* Figure out what is being referred to.  If the id-expression
+	 was for a class template specialization, then we will have a
+	 TYPE_DECL at this point.  There is no need to do name lookup
+	 at this point in that case.  */
+      if (TREE_CODE (argument) != TYPE_DECL)
+	argument = cp_parser_lookup_name (parser, argument,
+					  /*is_type=*/false,
+					  /*is_template=*/template_p,
+					  /*is_namespace=*/false,
+					  /*check_dependency=*/true);
       if (TREE_CODE (argument) != TEMPLATE_DECL
 	  && TREE_CODE (argument) != UNBOUND_CLASS_TEMPLATE)
 	cp_parser_error (parser, "expected template-name");

gcc/testsuite/ChangeLog

+2004-05-23  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/14821
+	* g++.dg/other/ns1.C: New test.
+
+	PR c++/14883
+	* g++.dg/template/invalid1.C: New test.
+
 2004-05-23  Paul Brook  <paul@codesourcery.com>
 	Victor Leikehman  <lei@haifasphere.co.il>
 

gcc/testsuite/g++.dg/other/ns1.C

+// PR c++/14821
+
+namespace A {
+  namespace B {}
+}
+
+namespace A {
+  namespace Alias = ::A::B;
+}
+
+namespace A {
+  namespace Alias = ::A::B;
+}

gcc/testsuite/g++.dg/template/invalid1.C

+// PR c++/14883
+
+template < class T > struct DomainTraits {};
+template < int Dim > class Interval;
+template < class DT > class Domain {};
+template <> class Interval < 1 >:public Domain < DomainTraits < Interval < 1 >
+>> {}; // { dg-error "" }