/*
 * Copyright (c) 2012, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.truffle.api;

import com.oracle.truffle.api.frame.*;
import com.oracle.truffle.api.nodes.*;

/**
 * Represents the target of a call to a {@link RootNode}, i.e., to another tree of nodes. Instances
 * of this class can be created using {@link TruffleRuntime#createCallTarget(RootNode)}.
 */
public abstract class RootCallTarget implements CallTarget {

    private final RootNode rootNode;

    public RootCallTarget(RootNode function) {
        this.rootNode = function;
        this.rootNode.adoptChildren();
        this.rootNode.setCallTarget(this);
    }

    @Override
    public String toString() {
        return rootNode.toString();
    }

    public final RootNode getRootNode() {
        return rootNode;
    }

    protected final Object callProxy(VirtualFrame frame) {
        try {
            return getRootNode().execute(frame);
        } finally {
            // this assertion is needed to keep the values from being cleared as non-live locals
            assert frame != null && this != null;
        }
    }
}