/*
 * 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.code.RuntimeCallTarget.Descriptor;
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 StateSplit, Canonicalizable, LIRLowerable {

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

    @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) {
        RuntimeCallTarget call = gen.getRuntime().lookupRuntimeCall(REGISTER_FINALIZER);
        gen.emitCall(call, call.getCallingConvention(), true, gen.operand(object()));
    }

    @Override
    public ValueNode canonical(CanonicalizerTool tool) {
        ObjectStamp stamp = object.objectStamp();

        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;
    }
}