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 org.apache.bcel.classfile.LineNumber; 021 022/** 023 * This class represents a line number within a method, i.e., give an instruction 024 * a line number corresponding to the source code line. 025 * 026 * @see LineNumber 027 * @see MethodGen 028 */ 029public class LineNumberGen implements InstructionTargeter, Cloneable { 030 031 private InstructionHandle ih; 032 private int src_line; 033 034 035 /** 036 * Create a line number. 037 * 038 * @param ih instruction handle to reference 039 */ 040 public LineNumberGen(final InstructionHandle ih, final int src_line) { 041 setInstruction(ih); 042 setSourceLine(src_line); 043 } 044 045 046 /** 047 * @return true, if ih is target of this line number 048 */ 049 @Override 050 public boolean containsTarget( final InstructionHandle ih ) { 051 return this.ih == ih; 052 } 053 054 055 /** 056 * @param old_ih old target 057 * @param new_ih new target 058 */ 059 @Override 060 public void updateTarget( final InstructionHandle old_ih, final InstructionHandle new_ih ) { 061 if (old_ih != ih) { 062 throw new ClassGenException("Not targeting " + old_ih + ", but " + ih + "}"); 063 } 064 setInstruction(new_ih); 065 } 066 067 068 /** 069 * Get LineNumber attribute . 070 * 071 * This relies on that the instruction list has already been dumped to byte code or 072 * or that the `setPositions' methods has been called for the instruction list. 073 */ 074 public LineNumber getLineNumber() { 075 return new LineNumber(ih.getPosition(), src_line); 076 } 077 078 079 public void setInstruction( final InstructionHandle ih ) { // TODO could be package-protected? 080 if (ih == null) { 081 throw new NullPointerException("InstructionHandle may not be null"); 082 } 083 BranchInstruction.notifyTarget(this.ih, ih, this); 084 this.ih = ih; 085 } 086 087 088 @Override 089 public Object clone() { 090 try { 091 return super.clone(); 092 } catch (final CloneNotSupportedException e) { 093 throw new Error("Clone Not Supported"); // never happens 094 } 095 } 096 097 098 public InstructionHandle getInstruction() { 099 return ih; 100 } 101 102 103 public void setSourceLine( final int src_line ) { // TODO could be package-protected? 104 this.src_line = src_line; 105 } 106 107 108 public int getSourceLine() { 109 return src_line; 110 } 111}