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