/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.sun.org.apache.bcel.internal.generic;

import com.sun.org.apache.bcel.internal.Const;

/**

 * Returnaddress, the type JSR or JSR_W instructions push upon the stack.

 *

 * see vmspec2 3.3.3

 */

public class ReturnaddressType extends Type {

    public static final ReturnaddressType NO_TARGET = new ReturnaddressType();

    private InstructionHandle returnTarget;

    /**

     * A Returnaddress [that doesn't know where to return to].

     */

    private ReturnaddressType() {

        super(Const.T_ADDRESS, "<return address>");

    }

    /**

     * Creates a ReturnaddressType object with a target.

     */

    public ReturnaddressType(final InstructionHandle returnTarget) {

        super(Const.T_ADDRESS, "<return address targeting " + returnTarget + ">");

        this.returnTarget = returnTarget;

    }

    /** @return a hash code value for the object.

     */

    @Override

    public int hashCode() {

        if (returnTarget == null) {

            return 0;

        }

        return returnTarget.hashCode();

    }

    /**

     * Returns if the two Returnaddresses refer to the same target.

     */

    @Override

    public boolean equals( final Object rat ) {

        if (!(rat instanceof ReturnaddressType)) {

            return false;

        }

        final ReturnaddressType that = (ReturnaddressType) rat;

        if (this.returnTarget == null || that.returnTarget == null) {

            return that.returnTarget == this.returnTarget;

        }

        return that.returnTarget.equals(this.returnTarget);

    }

    /**

     * @return the target of this ReturnaddressType

     */

    public InstructionHandle getTarget() {

        return returnTarget;

    }

}