Mercurial > hg > blitz_stable

comparison src/com/go/trove/classfile/LineNumberTableAttr.java @ 0:3dc0c5604566

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Initial checkin of blitz 2.0 fcs - no installer yet.
author Dan Creswell <dan.creswell@gmail.com>
date Sat, 21 Mar 2009 11:00:06 +0000
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-1:000000000000 0:3dc0c5604566
1 /* ====================================================================
2 * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group
3 * ====================================================================
4 * The Tea Software License, Version 1.1
5 *
6 * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. The end-user documentation included with the redistribution,
21 * if any, must include the following acknowledgment:
22 * "This product includes software developed by the
23 * Walt Disney Internet Group (http://opensource.go.com/)."
24 * Alternately, this acknowledgment may appear in the software itself,
25 * if and wherever such third-party acknowledgments normally appear.
26 *
27 * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must
28 * not be used to endorse or promote products derived from this
29 * software without prior written permission. For written
30 * permission, please contact opensource@dig.com.
31 *
32 * 5. Products derived from this software may not be called "Tea",
33 * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet",
34 * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior
35 * written permission of the Walt Disney Internet Group.
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 WALT DISNEY INTERNET GROUP OR ITS
41 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
42 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
43 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
44 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
45 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
46 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
47 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 *
50 * For more information about Tea, please see http://opensource.go.com/.
51 */
52
53 package com.go.trove.classfile;
54
55 import java.util.*;
56 import java.io.*;
57
58 /******************************************************************************
59 * This class corresponds to the LineNumberTable_attribute structure as
60 * defined in section 4.7.6 of <i>The Java Virtual Machine Specification</i>.
61 *
62 * @author Brian S O'Neill
63 * @version
64 * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 00/11/27 <!-- $-->
65 */
66 class LineNumberTableAttr extends Attribute {
67 private List mEntries = new ArrayList();
68 private boolean mClean = false;
69
70 public LineNumberTableAttr(ConstantPool cp) {
71 super(cp, LINE_NUMBER_TABLE);
72 }
73
74 public int getLineNumber(Location start) {
75 clean();
76 int index = Collections.binarySearch(mEntries, new Entry(start, 0));
77 if (index < 0) {
78 if ((index = -index - 2) < 0) {
79 return -1;
80 }
81 }
82 return ((Entry)mEntries.get(index)).mLineNumber;
83 }
84
85 public void addEntry(Location start, int line_number) {
86 check("line number", line_number);
87 mEntries.add(new Entry(start, line_number));
88 mClean = false;
89 }
90
91 public int getLength() {
92 clean();
93 return 2 + 4 * mEntries.size();
94 }
95
96 public void writeDataTo(DataOutput dout) throws IOException {
97 int size = mEntries.size();
98 dout.writeShort(size);
99 for (int i=0; i<size; i++) {
100 Entry entry = (Entry)mEntries.get(i);
101
102 int start_pc = entry.mStart.getLocation();
103
104 check("line number table entry start PC", start_pc);
105
106 dout.writeShort(start_pc);
107 dout.writeShort(entry.mLineNumber);
108 }
109 }
110
111 private void check(String type, int addr) throws RuntimeException {
112 if (addr < 0 || addr > 65535) {
113 throw new RuntimeException("Value for " + type + " out of " +
114 "valid range: " + addr);
115
116 }
117 }
118
119 private void clean() {
120 if (!mClean) {
121 mClean = true;
122
123 // Clean things up by removing multiple mappings of the same
124 // start_pc to line numbers. Only keep the last one.
125 // This has to be performed now because the Labels should have
126 // a pc location, but before they did not. Since entries must be
127 // sorted ascending by start_pc, use a sorted set.
128
129 Set reduced = new TreeSet();
130 for (int i = mEntries.size(); --i >= 0; ) {
131 reduced.add(mEntries.get(i));
132 }
133
134 mEntries = new ArrayList(reduced);
135 }
136 }
137
138 static Attribute define(ConstantPool cp,
139 String name,
140 int length,
141 DataInput din) throws IOException {
142
143 LineNumberTableAttr lineNumbers = new LineNumberTableAttr(cp);
144
145 int size = din.readUnsignedShort();
146 for (int i=0; i<size; i++) {
147 int start_pc = din.readUnsignedShort();
148 int line_number = din.readUnsignedShort();
149
150 lineNumbers.addEntry(new FixedLocation(start_pc), line_number);
151 }
152
153 return lineNumbers;
154 }
155
156 private static class Entry implements Comparable {
157 public final Location mStart;
158 public final int mLineNumber;
159
160 public Entry(Location start, int line_number) {
161 mStart = start;
162 mLineNumber = line_number;
163 }
164
165 public int compareTo(Object other) {
166 int thisLoc = mStart.getLocation();
167 int thatLoc = ((Entry)other).mStart.getLocation();
168
169 if (thisLoc < thatLoc) {
170 return -1;
171 }
172 else if (thisLoc > thatLoc) {
173 return 1;
174 }
175 else {
176 return 0;
177 }
178 }
179
180 public boolean equals(Object other) {
181 if (other instanceof Entry) {
182 return mStart.getLocation() ==
183 ((Entry)other).mStart.getLocation();
184 }
185 return false;
186 }
187
188 public String toString() {
189 return "start_pc=" + mStart.getLocation() + " => " +
190 "line_number=" + mLineNumber;
191 }
192 }
193 }