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