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Java > Open Source Codes > jbet > ExceptionRec


1 /*
2  * JBET - Java Binary Enhancement Tool
3  * Copyright (c) 2003 Networks Associates Technology, Inc.
4  *
5  * This software was developed under DARPA/SPAWAR contract
6  * N66001-00-C-8602 "SPMA" as part of the
7  * DARPA OASIS research program.
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  * 1. Redistributions of source code must retain the above copyright
13  * notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  * notice, this list of conditions and the following disclaimer in the
16  * documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30
31 /**
32  * This class defines a record used for storing exception records. Each
33  * Code attribute contains a table of exception records. Each record
34  * stores the range of instructions for which an exception is active,
35  * the range of instructions that implement the exception handler, and
36  * the class of the exception that is handled.
37  *
38  * When we insert new instructions into a method (see CodeEditor), the
39  * ranges become invalid, and need to be updated.
40  *
41  * $Id: ExceptionRec.java,v 1.8 2003/09/09 17:31:53 areisse Exp $
42  *
43  * @author Lee Badger
44  * @version 0.1
45  * @since JDK 1.1.8
46  */
47
48
49 /* the range inside of the try{} is [start, end].
50    This differs from the way it is stored in a .class file
51    which is [start, end) */
52
53 package jbet;
54 import java.util.*;
55 import java.io.*;
56
57 public class ExceptionRec implements Cloneable JavaDoc {
58
59     public BranchTarget start = new BranchTarget(); // try {
60 public BranchTarget end = new BranchTarget(); // } /* try */
61 public BranchTarget handler = new BranchTarget(); // catch (...) {
62 public String JavaDoc catchType; // type ^^^
63 int catchIndex; // The index into the constant pool of the catchType.
64
65     int marker;
66
67     ExceptionRec dup() {
68     try {
69         return (ExceptionRec) clone();
70     } catch (CloneNotSupportedException JavaDoc e) {
71         return null;
72     }
73     }
74     
75     public ExceptionRec (Instruction start, Instruction end, Instruction handler, String JavaDoc ct) {
76     this.start.instr = start;
77     this.end.instr = end;
78     this.handler.instr = handler;
79     catchType = ct;
80     }
81
82     ExceptionRec (DataInputStream dataIn, ConstantPool constantPool)
83     throws IOException, ClassFileException {
84     
85     start.offset = dataIn.readUnsignedShort();
86     end.offset = dataIn.readUnsignedShort();
87     handler.offset = dataIn.readUnsignedShort();
88
89     catchIndex = dataIn.readUnsignedShort();
90     catchType = catchIndex == 0 ? null : constantPool.cpClassAt(catchIndex).string();
91     }
92     
93
94     void resolveConstants(ConstantPool constantPool) {
95     if (catchType != null)
96         catchIndex = constantPool.internClass(catchType);
97     else
98         catchIndex = 0;
99     }
100
101     void writeFile (DataOutputStream dataOut) throws IOException {
102     dataOut.writeShort (start.offset);
103     dataOut.writeShort (end.offset);
104     dataOut.writeShort (handler.offset);
105     dataOut.writeShort (catchIndex );
106     }
107     
108
109     void print (LineWriter out) {
110     out.println ("\tException: PCrange(" + start.instr.pc() + "-" +
111              (end.instr==null?"":""+end.instr.pc()) + ") handlerPC(" +
112              handler.instr.pc() + ") catchType(" + catchType + ")" );
113     }
114
115     ExceptionRec () {};
116
117
118
119 }
120
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