/*

 * Copyright (c) 2012, 2018, 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 org.graalvm.compiler.nodes;

import org.graalvm.compiler.core.common.type.Stamp;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.nodeinfo.InputType;

import org.graalvm.compiler.nodeinfo.NodeInfo;

/**

 * Base class for {@link AbstractBeginNode}s that are associated with a frame state.

 *

 * TODO (dnsimon) this not needed until {@link AbstractBeginNode} no longer implements

 * {@link StateSplit} which is not possible until loop peeling works without requiring begin nodes

 * to have frames states.

 */

@NodeInfo

public abstract class BeginStateSplitNode extends AbstractBeginNode implements StateSplit {

    public static final NodeClass<BeginStateSplitNode> TYPE = NodeClass.create(BeginStateSplitNode.class);

    @OptionalInput(InputType.State) protected FrameState stateAfter;

    protected BeginStateSplitNode(NodeClass<? extends BeginStateSplitNode> c) {

        super(c);

    }

    protected BeginStateSplitNode(NodeClass<? extends BeginStateSplitNode> c, Stamp stamp) {

        super(c, stamp);

    }

    @Override

    public FrameState stateAfter() {

        return stateAfter;

    }

    @Override

    public void setStateAfter(FrameState x) {

        assert x == null || x.isAlive() : "frame state must be in a graph";

        updateUsages(stateAfter, x);

        stateAfter = x;

    }

    /**

     * A begin node has no side effect.

     */

    @Override

    public boolean hasSideEffect() {

        return false;

    }

}