[C++0x] Variadic templates with using declarations, attributes (PR c++/34051)

["Doug Gregor" <doug dot gregor at gmail dot com>]

The attached patch fixes PR c++/34051, a P2 where we failed to
properly check for bare parameter packs in using declarations and
declaration attributes. This patch fixes both the ICE and produces
appropriate diagnostics for the ill-formed examples in the PR.

Tested i686-pc-linux-gnu. Okay for mainline?

  - Doug

2007-12-04  Douglas Gregor  <doug.gregor@gmail.com>

	PR c++/34051
	* tree.c (cp_walk_subtrees): Walk USING_DECL nodes.
	* pt.c (find_parameter_packs_r): Look at the type of
	IDENTIFIER_NODEs (e.g., for user-defined conversions).
	* semantics.c (finish_member_declaration): Check the attributes of
	the declaration for bare parameter packs.
	* parser.c (cp_parser_using_declaration): Check the using
	declaration for bare parameter packs.

2007-12-04  Douglas Gregor  <doug.gregor@gmail.com>

	PR c++/34051
	* testsuite/g++.dg/cpp0x/vt-34051.C: New.
	* testsuite/g++.dg/cpp0x/vt-34051-2.C: New.

Index: cp/tree.c
===================================================================
--- cp/tree.c	(revision 130615)
+++ cp/tree.c	(working copy)
@@ -2351,6 +2351,13 @@ cp_walk_subtrees (tree *tp, int *walk_su
       *walk_subtrees_p = 0;
       break;
 
+    case USING_DECL:
+      WALK_SUBTREE (DECL_NAME (*tp));
+      WALK_SUBTREE (USING_DECL_SCOPE (*tp));
+      WALK_SUBTREE (USING_DECL_DECLS (*tp));
+      *walk_subtrees_p = 0;
+      break;
+
     case RECORD_TYPE:
       if (TYPE_PTRMEMFUNC_P (*tp))
 	WALK_SUBTREE (TYPE_PTRMEMFUNC_FN_TYPE (*tp));
Index: cp/pt.c
===================================================================
--- cp/pt.c	(revision 130615)
+++ cp/pt.c	(working copy)
@@ -2576,6 +2576,11 @@ recheck:
       *walk_subtrees = 0;
       return NULL_TREE;
 
+    case IDENTIFIER_NODE:
+      cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd, NULL);
+      *walk_subtrees = 0;
+      return NULL_TREE;
+
     default:
       return NULL_TREE;
     }
Index: cp/semantics.c
===================================================================
--- cp/semantics.c	(revision 130615)
+++ cp/semantics.c	(working copy)
@@ -2321,7 +2321,10 @@ finish_member_declaration (tree decl)
 
   /* Check for bare parameter packs in the member variable declaration.  */
   if (TREE_CODE (decl) == FIELD_DECL)
-    check_for_bare_parameter_packs (&TREE_TYPE (decl));
+    {
+      check_for_bare_parameter_packs (&TREE_TYPE (decl));
+      check_for_bare_parameter_packs (&DECL_ATTRIBUTES (decl));
+    }
 
   /* [dcl.link]
 
Index: cp/parser.c
===================================================================
--- cp/parser.c	(revision 130615)
+++ cp/parser.c	(working copy)
@@ -11744,14 +11744,20 @@ cp_parser_using_declaration (cp_parser* 
 	{
 	  /* Create the USING_DECL.  */
 	  decl = do_class_using_decl (parser->scope, identifier);
-	  /* Add it to the list of members in this class.  */
-	  finish_member_declaration (decl);
+
+	  if (check_for_bare_parameter_packs (&decl))
+	    /* Add it to the list of members in this class.  */
+	    finish_member_declaration (decl);
+	  else
+	    return false;
 	}
       else
 	{
 	  decl = cp_parser_lookup_name_simple (parser, identifier);
 	  if (decl == error_mark_node)
 	    cp_parser_name_lookup_error (parser, identifier, decl, NULL);
+	  else if (!check_for_bare_parameter_packs (&decl))
+	    return false;
 	  else if (!at_namespace_scope_p ())
 	    do_local_using_decl (decl, qscope, identifier);
 	  else
Index: testsuite/g++.dg/cpp0x/vt-34051-2.C
===================================================================
--- testsuite/g++.dg/cpp0x/vt-34051-2.C	(revision 0)
+++ testsuite/g++.dg/cpp0x/vt-34051-2.C	(revision 0)
@@ -0,0 +1,7 @@
+// { dg-options "-std=c++0x" }
+template<typename... T> struct A
+{
+  int i __attribute__((aligned(__alignof(T)))); // { dg-error "parameter packs|T|requested" }
+};
+
+A<int> a; // { dg-error "from here" }
Index: testsuite/g++.dg/cpp0x/vt-34051.C
===================================================================
--- testsuite/g++.dg/cpp0x/vt-34051.C	(revision 0)
+++ testsuite/g++.dg/cpp0x/vt-34051.C	(revision 0)
@@ -0,0 +1,12 @@
+// { dg-options "-std=c++0x" }
+struct A
+{
+  operator int();
+};
+
+template <typename... T> struct B : A
+{
+  using A::operator T; // { dg-error "parameter packs|T" }
+};
+
+B<int> b;