1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 package org.apache.bcel.generic; 19 20 import java.io.DataOutputStream; 21 import java.io.IOException; 22 23 /** 24 * JSR - Jump to subroutine 25 * 26 * @version $Id$ 27 */ 28 public class JSR extends JsrInstruction implements VariableLengthInstruction { 29 30 /** 31 * Empty constructor needed for Instruction.readInstruction. 32 * Not to be used otherwise. 33 */ 34 JSR() { 35 } 36 37 38 public JSR(final InstructionHandle target) { 39 super(org.apache.bcel.Const.JSR, target); 40 } 41 42 43 /** 44 * Dump instruction as byte code to stream out. 45 * @param out Output stream 46 */ 47 @Override 48 public void dump( final DataOutputStream out ) throws IOException { 49 super.setIndex(getTargetOffset()); 50 if (super.getOpcode() == org.apache.bcel.Const.JSR) { 51 super.dump(out); 52 } else { // JSR_W 53 super.setIndex(getTargetOffset()); 54 out.writeByte(super.getOpcode()); 55 out.writeInt(super.getIndex()); 56 } 57 } 58 59 60 @Override 61 protected int updatePosition( final int offset, final int max_offset ) { 62 final int i = getTargetOffset(); // Depending on old position value 63 setPosition(getPosition() + offset); // Position may be shifted by preceding expansions 64 if (Math.abs(i) >= (Short.MAX_VALUE - max_offset)) { // to large for short (estimate) 65 super.setOpcode(org.apache.bcel.Const.JSR_W); 66 final short old_length = (short) super.getLength(); 67 super.setLength(5); 68 return super.getLength() - old_length; 69 } 70 return 0; 71 } 72 73 74 /** 75 * Call corresponding visitor method(s). The order is: 76 * Call visitor methods of implemented interfaces first, then 77 * call methods according to the class hierarchy in descending order, 78 * i.e., the most specific visitXXX() call comes last. 79 * 80 * @param v Visitor object 81 */ 82 @Override 83 public void accept( final Visitor v ) { 84 v.visitStackProducer(this); 85 v.visitVariableLengthInstruction(this); 86 v.visitBranchInstruction(this); 87 v.visitJsrInstruction(this); 88 v.visitJSR(this); 89 } 90 } 91