001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 */
017
018package org.apache.bcel.generic;
019
020/**
021 * Denotes that a class targets InstructionHandles within an InstructionList.
022 *
023 * @see BranchHandle
024 * @see LocalVariableGen
025 * @see CodeExceptionGen
026 */
027public interface InstructionTargeter {
028
029    // static final InstructionTargeter[] EMPTY_ARRAY = new InstructionTargeter[0];
030
031    /**
032     * Tests whether this targeter targets the specified instruction handle.
033     *
034     * @param instructionHandle the instruction handle to test.
035     * @return whether this targeter targets the specified instruction handle.
036     */
037    boolean containsTarget(InstructionHandle instructionHandle);
038
039    /**
040     * Replaces the target of this targeter from this old handle to the new handle.
041     *
042     * @param oldIh the old handle
043     * @param newIh the new handle
044     * @throws ClassGenException if oldIh is not targeted by this object
045     */
046    void updateTarget(InstructionHandle oldIh, InstructionHandle newIh) throws ClassGenException;
047}