view src/share/vm/ci/ciNullObject.hpp @ 1941:79d04223b8a5

Added caching for resolved types and resolved fields. This is crucial, because the local load elimination will lead to wrong results, if field equality (of two RiField objects with the same object and the same RiType) is not given. The caching makes sure that the default equals implementation is sufficient.
author Thomas Wuerthinger <wuerthinger@ssw.jku.at>
date Tue, 28 Dec 2010 18:33:26 +0100
parents c18cbe5936b8
children f95d63e2154a
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/*
 * Copyright (c) 1999, 2000, 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.
 *
 */

// ciNullObject
//
// This class represents a null reference in the VM.
class ciNullObject : public ciObject {
  CI_PACKAGE_ACCESS

private:
  ciNullObject() : ciObject() {}

  const char* type_string() { return "ciNullObject"; }

  void print_impl(outputStream* st);

public:
  // Is this ciObject a Java Language Object?  That is,
  // is the ciObject an instance or an array
  bool is_java_object() { return true; }

  // What kind of ciObject is this?
  bool is_null_object() const { return true; }
  bool is_classless() const   { return true; }

  // Get the distinguished instance of this klass.
  static ciNullObject* make();
};