001/*
002 * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.nodes;
024
025import com.oracle.graal.graph.*;
026import com.oracle.graal.nodeinfo.*;
027
028/**
029 * Base class for nodes that contain "virtual" state, like FrameState and VirtualObjectState.
030 * Subclasses of this class will be treated in a special way by the scheduler.
031 */
032@NodeInfo(allowedUsageTypes = {InputType.State})
033public abstract class VirtualState extends Node {
034
035    protected VirtualState(NodeClass<? extends VirtualState> c) {
036        super(c);
037    }
038
039    public static final NodeClass<VirtualState> TYPE = NodeClass.create(VirtualState.class);
040
041    public abstract static class NodeClosure<T extends Node> {
042
043        public abstract void apply(Node usage, T node);
044    }
045
046    public interface VirtualClosure {
047
048        void apply(VirtualState node);
049    }
050
051    public abstract VirtualState duplicateWithVirtualState();
052
053    public abstract void applyToNonVirtual(NodeClosure<? super ValueNode> closure);
054
055    /**
056     * Performs a <b>pre-order</b> iteration over all elements reachable from this state that are a
057     * subclass of {@link VirtualState}.
058     */
059    public abstract void applyToVirtual(VirtualClosure closure);
060
061    public abstract boolean isPartOfThisState(VirtualState state);
062
063    @Override
064    public final StructuredGraph graph() {
065        return (StructuredGraph) super.graph();
066    }
067
068}