re PR c++/63849 ([c++11] ICE on variadic alias template with wrappers)

	PR c++/63849
	* mangle.c (decl_mangling_context): Use template_type_parameter_p.

From-SVN: r217949

gcc/cp/ChangeLog

 2014-11-21  Jason Merrill  <jason@redhat.com>
 
+	PR c++/63849
+	* mangle.c (decl_mangling_context): Use template_type_parameter_p.
+
 	PR c++/63588
 	* pt.c (uses_template_parms): Handle null argument.
 

gcc/cp/mangle.c

@@ -764,8 +764,7 @@ decl_mangling_context (tree decl)
       if (extra)
 	return extra;
     }
-    else if (TREE_CODE (decl) == TYPE_DECL
-	     && TREE_CODE (TREE_TYPE (decl)) == TEMPLATE_TYPE_PARM)
+  else if (template_type_parameter_p (decl))
      /* template type parms have no mangling context.  */
       return NULL_TREE;
   return CP_DECL_CONTEXT (decl);

gcc/testsuite/g++.dg/cpp0x/alias-decl-44.C

+// PR c++/63849
+// { dg-do compile { target c++11 } }
+
+template <class _T, class...>
+using First = _T;            // we should not use this
+                             // alias with only
+                             // one pack parameter (?)
+
+template <template <class...> class _Successor,
+          int,
+          class... _Xs>
+struct Overlay
+{
+    using O = _Successor<_Xs...>;
+};
+
+template <class... _Pack>
+struct List
+{
+    template <int _s>
+    using O = typename Overlay<List, _s, _Pack...>::O;
+
+    template <template <class...> class _S>
+    using Pass = _S<_Pack...>;
+
+    template <int _i>
+    using At = typename O<_i>
+    ::template Pass<First>;
+};
+
+template <int _i>
+using At = typename List<int, char>
+::template At<_i>;
+
+template <int _i>
+void func_crash(At<_i>&) {}
+
+int main(int argc, char *argv[])
+{
+    char ccc;
+    int iii;
+    func_crash<0>(iii);
+}