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1 package org.apache.bcel.classfile; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache BCEL" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * "Apache BCEL", nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 */ 56 57 import org.apache.bcel.Constants; 58 import java.io.*; 59 60 /*** 61 * This class represents a table of line numbers for debugging 62 * purposes. This attribute is used by the <em>Code</em> attribute. It 63 * contains pairs of PCs and line numbers. 64 * 65 * @version $Id: LineNumberTable.java,v 1.3 2002/12/08 16:04:37 mdahm Exp $ 66 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> 67 * @see Code 68 * @see LineNumber 69 */ 70 public final class LineNumberTable extends Attribute { 71 private int line_number_table_length; 72 private LineNumber[] line_number_table; // Table of line/numbers pairs 73 74 /* 75 * Initialize from another object. Note that both objects use the same 76 * references (shallow copy). Use copy() for a physical copy. 77 */ 78 public LineNumberTable(LineNumberTable c) { 79 this(c.getNameIndex(), c.getLength(), c.getLineNumberTable(), 80 c.getConstantPool()); 81 } 82 83 /* 84 * @param name_index Index of name 85 * @param length Content length in bytes 86 * @param line_number_table Table of line/numbers pairs 87 * @param constant_pool Array of constants 88 */ 89 public LineNumberTable(int name_index, int length, 90 LineNumber[] line_number_table, 91 ConstantPool constant_pool) 92 { 93 super(Constants.ATTR_LINE_NUMBER_TABLE, name_index, length, constant_pool); 94 setLineNumberTable(line_number_table); 95 } 96 97 /*** 98 * Construct object from file stream. 99 * @param name_index Index of name 100 * @param length Content length in bytes 101 * @param file Input stream 102 * @throws IOException 103 * @param constant_pool Array of constants 104 */ 105 LineNumberTable(int name_index, int length, DataInputStream file, 106 ConstantPool constant_pool) throws IOException 107 { 108 this(name_index, length, (LineNumber[])null, constant_pool); 109 line_number_table_length = (file.readUnsignedShort()); 110 line_number_table = new LineNumber[line_number_table_length]; 111 112 for(int i=0; i < line_number_table_length; i++) 113 line_number_table[i] = new LineNumber(file); 114 } 115 /*** 116 * Called by objects that are traversing the nodes of the tree implicitely 117 * defined by the contents of a Java class. I.e., the hierarchy of methods, 118 * fields, attributes, etc. spawns a tree of objects. 119 * 120 * @param v Visitor object 121 */ 122 public void accept(Visitor v) { 123 v.visitLineNumberTable(this); 124 } 125 /*** 126 * Dump line number table attribute to file stream in binary format. 127 * 128 * @param file Output file stream 129 * @throws IOException 130 */ 131 public final void dump(DataOutputStream file) throws IOException 132 { 133 super.dump(file); 134 file.writeShort(line_number_table_length); 135 for(int i=0; i < line_number_table_length; i++) 136 line_number_table[i].dump(file); 137 } 138 139 /*** 140 * @return Array of (pc offset, line number) pairs. 141 */ 142 public final LineNumber[] getLineNumberTable() { return line_number_table; } 143 144 /*** 145 * @param line_number_table. 146 */ 147 public final void setLineNumberTable(LineNumber[] line_number_table) { 148 this.line_number_table = line_number_table; 149 150 line_number_table_length = (line_number_table == null)? 0 : 151 line_number_table.length; 152 } 153 154 /*** 155 * @return String representation. 156 */ 157 public final String toString() { 158 StringBuffer buf = new StringBuffer(); 159 StringBuffer line = new StringBuffer(); 160 161 for(int i=0; i < line_number_table_length; i++) { 162 line.append(line_number_table[i].toString()); 163 164 if(i < line_number_table_length - 1) 165 line.append(", "); 166 167 if(line.length() > 72) { 168 line.append('\n'); 169 buf.append(line); 170 line.setLength(0); 171 } 172 } 173 174 buf.append(line); 175 176 return buf.toString(); 177 } 178 179 /*** 180 * Map byte code positions to source code lines. 181 * 182 * @param pos byte code offset 183 * @return corresponding line in source code 184 */ 185 public int getSourceLine(int pos) { 186 int l = 0, r = line_number_table_length-1; 187 188 if(r < 0) // array is empty 189 return -1; 190 191 int min_index = -1, min=-1; 192 193 /* Do a binary search since the array is ordered. 194 */ 195 do { 196 int i = (l + r) / 2; 197 int j = line_number_table[i].getStartPC(); 198 199 if(j == pos) 200 return line_number_table[i].getLineNumber(); 201 else if(pos < j) // else constrain search area 202 r = i - 1; 203 else // pos > j 204 l = i + 1; 205 206 /* If exact match can't be found (which is the most common case) 207 * return the line number that corresponds to the greatest index less 208 * than pos. 209 */ 210 if(j < pos && j > min) { 211 min = j; 212 min_index = i; 213 } 214 } while(l <= r); 215 216 /* It's possible that we did not find any valid entry for the bytecode 217 * offset we were looking for. 218 */ 219 if (min_index < 0) 220 return -1; 221 222 return line_number_table[min_index].getLineNumber(); 223 } 224 225 /*** 226 * @return deep copy of this attribute 227 */ 228 public Attribute copy(ConstantPool constant_pool) { 229 LineNumberTable c = (LineNumberTable)clone(); 230 231 c.line_number_table = new LineNumber[line_number_table_length]; 232 for(int i=0; i < line_number_table_length; i++) 233 c.line_number_table[i] = line_number_table[i].copy(); 234 235 c.constant_pool = constant_pool; 236 return c; 237 } 238 239 public final int getTableLength() { return line_number_table_length; } 240 }

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