--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/oops/metadata.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2011, 2014, 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.
+ *
+ */
+
+#ifndef SHARE_VM_OOPS_METADATA_HPP
+#define SHARE_VM_OOPS_METADATA_HPP
+
+#include "utilities/exceptions.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/ostream.hpp"
+
+// This is the base class for an internal Class related metadata
+class Metadata : public MetaspaceObj {
+  // Debugging hook to check that the metadata has not been deleted.
+  NOT_PRODUCT(int _valid;)
+ public:
+  NOT_PRODUCT(Metadata()     { _valid = 0; })
+  NOT_PRODUCT(bool is_valid() const volatile { return _valid == 0; })
+
+  int identity_hash()                { return (int)(uintptr_t)this; }
+
+  // Rehashing support for tables containing pointers to this
+  unsigned int new_hash(juint seed)   { ShouldNotReachHere();  return 0; }
+
+  virtual bool is_metadata()           const volatile { return true; }
+  virtual bool is_klass()              const volatile { return false; }
+  virtual bool is_method()             const volatile { return false; }
+  virtual bool is_methodData()         const volatile { return false; }
+  virtual bool is_constantPool()       const volatile { return false; }
+  virtual bool is_methodCounters()     const volatile { return false; }
+  virtual int  size()                  const = 0;
+  virtual MetaspaceObj::Type type()    const = 0;
+  virtual const char* internal_name()  const = 0;
+  virtual void metaspace_pointers_do(MetaspaceClosure* iter) {}
+
+  void print()       const { print_on(tty); }
+  void print_value() const { print_value_on(tty); }
+
+  void print_maybe_null() const { print_on_maybe_null(tty); }
+  void print_on_maybe_null(outputStream* st) const {
+    if (this == NULL)
+      st->print("NULL");
+    else
+      print_on(st);
+  }
+  void print_value_on_maybe_null(outputStream* st) const {
+    if (this == NULL)
+      st->print("NULL");
+    else
+      print_value_on(st);
+  }
+
+  virtual void print_on(outputStream* st) const;       // First level print
+  virtual void print_value_on(outputStream* st) const = 0; // Second level print
+
+  char* print_value_string() const;
+
+  // Used to keep metadata alive during class redefinition
+  // Can't assert because is called for delete functions (as an assert)
+  virtual bool on_stack() const { return false; }
+  virtual void set_on_stack(const bool value);
+
+  // Set on_stack bit, so that the metadata is not cleared
+  // during class redefinition.  This is a virtual call because only methods
+  // and constant pools need to be set, but someday instanceKlasses might also.
+  static void mark_on_stack(Metadata* m) { m->set_on_stack(true); }
+};
+
+#endif // SHARE_VM_OOPS_METADATA_HPP