ciNullObject.hpp revision 1879:f95d63e2154a 
1/*
2 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25#ifndef SHARE_VM_CI_CINULLOBJECT_HPP
26#define SHARE_VM_CI_CINULLOBJECT_HPP
27
28#include "ci/ciClassList.hpp"
29#include "ci/ciObject.hpp"
30#include "ci/ciUtilities.hpp"
31
32// ciNullObject
33//
34// This class represents a null reference in the VM.
35class ciNullObject : public ciObject {
36  CI_PACKAGE_ACCESS
37
38private:
39  ciNullObject() : ciObject() {}
40
41  const char* type_string() { return "ciNullObject"; }
42
43  void print_impl(outputStream* st);
44
45public:
46  // Is this ciObject a Java Language Object?  That is,
47  // is the ciObject an instance or an array
48  bool is_java_object() { return true; }
49
50  // What kind of ciObject is this?
51  bool is_null_object() const { return true; }
52  bool is_classless() const   { return true; }
53
54  // Get the distinguished instance of this klass.
55  static ciNullObject* make();
56};
57
58#endif // SHARE_VM_CI_CINULLOBJECT_HPP
59