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 020import java.io.DataOutputStream; 021import java.io.IOException; 022 023/** 024 * JSR - Jump to subroutine 025 * 026 * @version $Id: JSR.java 1812166 2017-10-13 23:48:11Z ggregory $ 027 */ 028public class JSR extends JsrInstruction implements VariableLengthInstruction { 029 030 /** 031 * Empty constructor needed for Instruction.readInstruction. 032 * Not to be used otherwise. 033 */ 034 JSR() { 035 } 036 037 038 public JSR(final InstructionHandle target) { 039 super(org.apache.bcel.Const.JSR, target); 040 } 041 042 043 /** 044 * Dump instruction as byte code to stream out. 045 * @param out Output stream 046 */ 047 @Override 048 public void dump( final DataOutputStream out ) throws IOException { 049 super.setIndex(getTargetOffset()); 050 if (super.getOpcode() == org.apache.bcel.Const.JSR) { 051 super.dump(out); 052 } else { // JSR_W 053 super.setIndex(getTargetOffset()); 054 out.writeByte(super.getOpcode()); 055 out.writeInt(super.getIndex()); 056 } 057 } 058 059 060 @Override 061 protected int updatePosition( final int offset, final int max_offset ) { 062 final int i = getTargetOffset(); // Depending on old position value 063 setPosition(getPosition() + offset); // Position may be shifted by preceding expansions 064 if (Math.abs(i) >= (Short.MAX_VALUE - max_offset)) { // to large for short (estimate) 065 super.setOpcode(org.apache.bcel.Const.JSR_W); 066 final short old_length = (short) super.getLength(); 067 super.setLength(5); 068 return super.getLength() - old_length; 069 } 070 return 0; 071 } 072 073 074 /** 075 * Call corresponding visitor method(s). The order is: 076 * Call visitor methods of implemented interfaces first, then 077 * call methods according to the class hierarchy in descending order, 078 * i.e., the most specific visitXXX() call comes last. 079 * 080 * @param v Visitor object 081 */ 082 @Override 083 public void accept( final Visitor v ) { 084 v.visitStackProducer(this); 085 v.visitVariableLengthInstruction(this); 086 v.visitBranchInstruction(this); 087 v.visitJsrInstruction(this); 088 v.visitJSR(this); 089 } 090}