/*
 * Copyright (c) 2011, 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.
 */
package com.oracle.graal.nodes.spi;

import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.java.*;
import com.oracle.graal.nodes.virtual.*;

/**
 * This interface allows a node to convey information about what its effect would be if some of its
 * inputs were virtualized. The {@link #virtualize(VirtualizerTool)} method will only be called for
 * nodes that have some interaction with virtualized nodes. However, the virtualized nodes might
 * have been re-materialized in the meantime.
 */
public interface Virtualizable {

    public static enum EscapeState {
        Virtual,
        Materialized
    }

    public abstract static class State {

        public abstract EscapeState getState();

        public abstract VirtualObjectNode getVirtualObject();

        public abstract ValueNode getEntry(int index);

        public abstract void addLock(MonitorIdNode monitorId);

        public abstract MonitorIdNode removeLock();

        public abstract ValueNode getMaterializedValue();
    }

    /**
     * A node class can implement this method to convey information about what its effect would be
     * if some of its inputs were virtualized. All modifications must be made through the supplied
     * tool, and not directly on the node, because by the time this method is called the
     * virtualized/non-virtualized state is still speculative and might not hold because of loops,
     * etc.
     * 
     * @param tool the tool used to describe the effects of this node
     */
    void virtualize(VirtualizerTool tool);
}
