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 * 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

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

/**

 * Super class for JSR - Jump to subroutine

 *

 */

public abstract class JsrInstruction extends BranchInstruction implements UnconditionalBranch,

        TypedInstruction, StackProducer {

    JsrInstruction(final short opcode, final InstructionHandle target) {

        super(opcode, target);

    }

    /**

     * Empty constructor needed for Instruction.readInstruction.

     * Not to be used otherwise.

     */

    JsrInstruction() {

    }

    /** @return return address type

     */

    @Override

    public Type getType( final ConstantPoolGen cp ) {

        return new ReturnaddressType(physicalSuccessor());

    }

    /**

     * Returns an InstructionHandle to the physical successor

     * of this JsrInstruction. <B>For this method to work,

     * this JsrInstruction object must not be shared between

     * multiple InstructionHandle objects!</B>

     * Formally, there must not be InstructionHandle objects

     * i, j where i != j and i.getInstruction() == this ==

     * j.getInstruction().

     * @return an InstructionHandle to the "next" instruction that

     * will be executed when RETurned from a subroutine.

     */

    public InstructionHandle physicalSuccessor() {

        InstructionHandle ih = super.getTarget();

        // Rewind!

        while (ih.getPrev() != null) {

            ih = ih.getPrev();

        }

        // Find the handle for "this" JsrInstruction object.

        while (ih.getInstruction() != this) {

            ih = ih.getNext();

        }

        final InstructionHandle toThis = ih;

        while (ih != null) {

            ih = ih.getNext();

            if ((ih != null) && (ih.getInstruction() == this)) {

                throw new IllegalStateException("physicalSuccessor() called on a shared JsrInstruction.");

            }

        }

        // Return the physical successor

        return toThis.getNext();

    }

}