--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zOopClosures.cpp	2018-06-08 19:46:26.614999141 +0200
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include "precompiled.hpp"
+#include "gc/z/zHeap.hpp"
+#include "gc/z/zOopClosures.inline.hpp"
+#include "gc/z/zOop.inline.hpp"
+#include "memory/iterator.inline.hpp"
+#include "oops/access.inline.hpp"
+#include "oops/oop.inline.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+static void z_verify_loaded_object(const oop* p, const oop obj) {
+  guarantee(ZOop::is_good_or_null(obj),
+            "Bad oop " PTR_FORMAT " found at " PTR_FORMAT ", expected " PTR_FORMAT,
+            p2i(obj), p2i(p), p2i(ZOop::good(obj)));
+  guarantee(oopDesc::is_oop_or_null(obj),
+            "Bad object " PTR_FORMAT " found at " PTR_FORMAT,
+            p2i(obj), p2i(p));
+}
+
+ZVerifyHeapOopClosure::ZVerifyHeapOopClosure(oop base)
+    : _base(base) {}
+
+void ZVerifyHeapOopClosure::do_oop(oop* p) {
+  guarantee(ZHeap::heap()->is_in((uintptr_t)p), "oop* " PTR_FORMAT " not in heap", p2i(p));
+
+  const oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_base, _base->field_offset(p));
+  z_verify_loaded_object(p, obj);
+}
+
+void ZVerifyHeapOopClosure::do_oop(narrowOop* p) {
+  ShouldNotReachHere();
+}
+
+void ZVerifyRootOopClosure::do_oop(oop* p) {
+  guarantee(!ZHeap::heap()->is_in((uintptr_t)p), "oop* " PTR_FORMAT " in heap", p2i(p));
+
+  const oop obj = RootAccess<>::oop_load(p);
+  z_verify_loaded_object(p, obj);
+}
+
+void ZVerifyRootOopClosure::do_oop(narrowOop* p) {
+  ShouldNotReachHere();
+}
+
+void ZVerifyObjectClosure::do_object(oop o) {
+  ZVerifyHeapOopClosure cl(o);
+  o->oop_iterate(&cl);
+}
+
+// Generate Z specialized oop_oop_iterate functions.
+SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_Z(ALL_KLASS_OOP_OOP_ITERATE_DEFN)