re PR c++/85140 (ICE with invalid use of alignas)

	PR c++/85140
	* name-lookup.c (handle_namespace_attrs): Return early if attributes
	is error_mark_node.

	* g++.dg/cpp0x/gen-attrs-64.C: New test.

From-SVN: r259039

gcc/cp/ChangeLog

 2018-04-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/85140
+	* name-lookup.c (handle_namespace_attrs): Return early if attributes
+	is error_mark_node.
+
 	PR c++/85134
 	* decl.c (cp_finish_decl): If ensure_literal_type_for_constexpr_object
 	fails, after clearing DECL_DECLARED_CONSTEXPR_P don't return early,

gcc/cp/name-lookup.c

@@ -5044,6 +5044,9 @@ handle_namespace_attrs (tree ns, tree attributes)
   tree d;
   bool saw_vis = false;
 
+  if (attributes == error_mark_node)
+    return false;
+
   for (d = attributes; d; d = TREE_CHAIN (d))
     {
       tree name = get_attribute_name (d);

gcc/testsuite/ChangeLog

 2018-04-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/85140
+	* g++.dg/cpp0x/gen-attrs-64.C: New test.
+
 	PR c++/85134
 	* g++.dg/gomp/pr85134.C: New test.
 	* g++.dg/cpp0x/constexpr-ice19.C: Expect one further error.

gcc/testsuite/g++.dg/cpp0x/gen-attrs-64.C

+// PR c++/85140
+// { dg-do compile { target c++11 } }
+
+namespace N alignas() {}	// { dg-error "expected" }