/*
 * Copyright (c) 2011, 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.java;

import com.oracle.graal.api.code.*;
import com.oracle.graal.api.meta.*;
import com.oracle.graal.graph.*;
import com.oracle.graal.graph.spi.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.spi.*;
import com.oracle.graal.nodes.type.*;

/**
 * This node is used to perform the finalizer registration at the end of the java.lang.Object
 * constructor.
 */
public final class RegisterFinalizerNode extends AbstractStateSplit implements Canonicalizable, LIRLowerable, Virtualizable, DeoptimizingNode {

    public static final ForeignCallDescriptor REGISTER_FINALIZER = new ForeignCallDescriptor("registerFinalizer", void.class, Object.class);

    @Input private FrameState deoptState;
    @Input private ValueNode object;

    public ValueNode object() {
        return object;
    }

    public RegisterFinalizerNode(ValueNode object) {
        super(StampFactory.forVoid());
        this.object = object;
    }

    @Override
    public void generate(LIRGeneratorTool gen) {
        ForeignCallLinkage linkage = gen.getCodeCache().lookupForeignCall(REGISTER_FINALIZER);
        gen.emitForeignCall(linkage, this, gen.operand(object()));
    }

    @Override
    public Node canonical(CanonicalizerTool tool) {
        if (!(object.stamp() instanceof ObjectStamp)) {
            return this;
        }

        ObjectStamp stamp = (ObjectStamp) object.stamp();

        boolean needsCheck = true;
        if (stamp.isExactType()) {
            needsCheck = stamp.type().hasFinalizer();
        } else if (stamp.type() != null && !stamp.type().hasFinalizableSubclass()) {
            // if either the declared type of receiver or the holder
            // can be assumed to have no finalizers
            if (tool.assumptions().useOptimisticAssumptions()) {
                tool.assumptions().recordNoFinalizableSubclassAssumption(stamp.type());
                needsCheck = false;
            }
        }

        if (!needsCheck) {
            return null;
        }

        return this;
    }

    @Override
    public void virtualize(VirtualizerTool tool) {
        State state = tool.getObjectState(object);
        if (state != null && !state.getVirtualObject().type().hasFinalizer()) {
            tool.delete();
        }
    }

    @Override
    public boolean canDeoptimize() {
        return true;
    }

    @Override
    public FrameState getDeoptimizationState() {
        return deoptState;
    }

    @Override
    public void setDeoptimizationState(FrameState f) {
        updateUsages(deoptState, f);
        deoptState = f;
    }

    @SuppressWarnings("unused")
    @NodeIntrinsic
    public static void register(Object thisObj) {
    }
}