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      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2014 Eric Lafortune (eric (at) graphics.cornell.edu)
      6  *
      7  * This program is free software; you can redistribute it and/or modify it
      8  * under the terms of the GNU General Public License as published by the Free
      9  * Software Foundation; either version 2 of the License, or (at your option)
     10  * any later version.
     11  *
     12  * This program is distributed in the hope that it will be useful, but WITHOUT
     13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
     15  * more details.
     16  *
     17  * You should have received a copy of the GNU General Public License along
     18  * with this program; if not, write to the Free Software Foundation, Inc.,
     19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
     20  */
     21 package proguard.classfile.attribute;
     22 
     23 import proguard.classfile.*;
     24 import proguard.classfile.attribute.visitor.*;
     25 
     26 /**
     27  * This Attribute represents a line number table attribute.
     28  *
     29  * @author Eric Lafortune
     30  */
     31 public class LineNumberTableAttribute extends Attribute
     32 {
     33     public int              u2lineNumberTableLength;
     34     public LineNumberInfo[] lineNumberTable;
     35 
     36 
     37     /**
     38      * Creates an uninitialized LineNumberTableAttribute.
     39      */
     40     public LineNumberTableAttribute()
     41     {
     42     }
     43 
     44 
     45     /**
     46      * Creates an initialized LineNumberTableAttribute.
     47      */
     48     public LineNumberTableAttribute(int              u2attributeNameIndex,
     49                                     int              u2lineNumberTableLength,
     50                                     LineNumberInfo[] lineNumberTable)
     51     {
     52         super(u2attributeNameIndex);
     53 
     54         this.u2lineNumberTableLength = u2lineNumberTableLength;
     55         this.lineNumberTable         = lineNumberTable;
     56     }
     57 
     58 
     59     /**
     60      * Returns the line number corresponding to the given byte code program
     61      * counter.
     62      */
     63     public int getLineNumber(int pc)
     64     {
     65         for (int index = u2lineNumberTableLength-1 ; index >= 0 ; index--)
     66         {
     67             LineNumberInfo info = lineNumberTable[index];
     68             if (pc >= info.u2startPC)
     69             {
     70                 return info.u2lineNumber;
     71             }
     72         }
     73 
     74         return u2lineNumberTableLength > 0 ?
     75             lineNumberTable[0].u2lineNumber :
     76             0;
     77     }
     78 
     79 
     80     /**
     81      * Returns the lowest line number, or 0 if there aren't any line numbers.
     82      */
     83     public int getLowestLineNumber()
     84     {
     85         if (u2lineNumberTableLength == 0)
     86         {
     87             return 0;
     88         }
     89 
     90         int lowestLineNumber = Integer.MAX_VALUE;
     91 
     92         for (int index = 0; index < u2lineNumberTableLength; index++)
     93         {
     94             int lineNumber = lineNumberTable[index].u2lineNumber;
     95             if (lineNumber < lowestLineNumber)
     96             {
     97                 lowestLineNumber = lineNumber;
     98             }
     99         }
    100 
    101         return lowestLineNumber;
    102     }
    103 
    104 
    105     /**
    106      * Returns the highest line number, or 0 if there aren't any line numbers.
    107      */
    108     public int getHighestLineNumber()
    109     {
    110         if (u2lineNumberTableLength == 0)
    111         {
    112             return 0;
    113         }
    114 
    115         int highestLineNumber = Integer.MIN_VALUE;
    116 
    117         for (int index = 0; index < u2lineNumberTableLength; index++)
    118         {
    119             int lineNumber = lineNumberTable[index].u2lineNumber;
    120             if (lineNumber > highestLineNumber)
    121             {
    122                 highestLineNumber = lineNumber;
    123             }
    124         }
    125 
    126         return highestLineNumber;
    127     }
    128 
    129 
    130     // Implementations for Attribute.
    131 
    132     public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, AttributeVisitor attributeVisitor)
    133     {
    134         attributeVisitor.visitLineNumberTableAttribute(clazz, method, codeAttribute, this);
    135     }
    136 
    137 
    138     /**
    139      * Applies the given visitor to all line numbers.
    140      */
    141     public void lineNumbersAccept(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberInfoVisitor lineNumberInfoVisitor)
    142     {
    143         for (int index = 0; index < u2lineNumberTableLength; index++)
    144         {
    145             // We don't need double dispatching here, since there is only one
    146             // type of LineNumberInfo.
    147             lineNumberInfoVisitor.visitLineNumberInfo(clazz, method, codeAttribute, lineNumberTable[index]);
    148         }
    149     }
    150 }
    151