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comparison src/com/go/trove/classfile/CodeAttr.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 /* ====================================================================
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 Code_attribute structure as defined in
60 * section 4.7.4 of <i>The Java Virtual Machine Specification</i>.
61 * To make it easier to create bytecode for the CodeAttr, use the
62 * CodeBuilder.
63 *
64 * @author Brian S O'Neill
65 * @version
66 * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 01/01/02 <!-- $-->
67 * @see Opcode
68 * @see CodeBuilder
69 */
70 public class CodeAttr extends Attribute {
71 private CodeBuffer mCodeBuffer;
72 private List mAttributes = new ArrayList(2);
73
74 private LineNumberTableAttr mLineNumberTable;
75 private LocalVariableTableAttr mLocalVariableTable;
76
77 CodeAttr(ConstantPool cp) {
78 super(cp, CODE);
79 }
80
81 /**
82 * Returns null if no CodeBuffer is defined for this CodeAttr.
83 */
84 public CodeBuffer getCodeBuffer() {
85 return mCodeBuffer;
86 }
87
88 public void setCodeBuffer(CodeBuffer code) {
89 mCodeBuffer = code;
90 }
91
92 /**
93 * Returns the line number in the source code from the given bytecode
94 * address (start_pc).
95 *
96 * @return -1 if no line number is mapped for the start_pc.
97 */
98 public int getLineNumber(Location start) {
99 if (mLineNumberTable == null || start.getLocation() < 0) {
100 return -1;
101 }
102 else {
103 return mLineNumberTable.getLineNumber(start);
104 }
105 }
106
107 /**
108 * Map a bytecode address (start_pc) to a line number in the source code
109 * as a debugging aid.
110 */
111 public void mapLineNumber(Location start, int line_number) {
112 if (mLineNumberTable == null) {
113 addAttribute(new LineNumberTableAttr(mCp));
114 }
115
116 mLineNumberTable.addEntry(start, line_number);
117 }
118
119 /**
120 * Indicate a local variable's use information be recorded in the
121 * ClassFile as a debugging aid. If the LocalVariable doesn't provide
122 * both a start and end location, then its information is not recorded.
123 * This method should be called at most once per LocalVariable instance.
124 */
125 public void localVariableUse(LocalVariable localVar) {
126 if (mLocalVariableTable == null) {
127 addAttribute(new LocalVariableTableAttr(mCp));
128 }
129
130 mLocalVariableTable.addEntry(localVar);
131 }
132
133 public void addAttribute(Attribute attr) {
134 if (attr instanceof LineNumberTableAttr) {
135 if (mLineNumberTable != null) {
136 mAttributes.remove(mLineNumberTable);
137 }
138 mLineNumberTable = (LineNumberTableAttr)attr;
139 }
140 else if (attr instanceof LocalVariableTableAttr) {
141 if (mLocalVariableTable != null) {
142 mAttributes.remove(mLocalVariableTable);
143 }
144 mLocalVariableTable = (LocalVariableTableAttr)attr;
145 }
146
147 mAttributes.add(attr);
148 }
149
150 public Attribute[] getAttributes() {
151 Attribute[] attrs = new Attribute[mAttributes.size()];
152 return (Attribute[])mAttributes.toArray(attrs);
153 }
154
155 /**
156 * Returns the length (in bytes) of this object in the class file.
157 */
158 public int getLength() {
159 int length = 12;
160
161 if (mCodeBuffer != null) {
162 length += mCodeBuffer.getByteCodes().length;
163 ExceptionHandler[] handlers = mCodeBuffer.getExceptionHandlers();
164 if (handlers != null) {
165 length += 8 * handlers.length;
166 }
167 }
168
169 int size = mAttributes.size();
170 for (int i=0; i<size; i++) {
171 length += ((Attribute)mAttributes.get(i)).getLength();
172 length += 6; // attributes have an intial 6 byte length
173 }
174
175 return length;
176 }
177
178 public void writeDataTo(DataOutput dout) throws IOException {
179 if (mCodeBuffer == null) {
180 throw new NullPointerException("CodeAttr has no CodeBuffer set");
181 }
182
183 ExceptionHandler[] handlers = mCodeBuffer.getExceptionHandlers();
184
185 dout.writeShort(mCodeBuffer.getMaxStackDepth());
186 dout.writeShort(mCodeBuffer.getMaxLocals());
187
188 byte[] byteCodes = mCodeBuffer.getByteCodes();
189 dout.writeInt(byteCodes.length);
190 dout.write(byteCodes);
191
192 if (handlers != null) {
193 int exceptionHandlerCount = handlers.length;
194 dout.writeShort(exceptionHandlerCount);
195
196 for (int i=0; i<exceptionHandlerCount; i++) {
197 handlers[i].writeTo(dout);
198 }
199 }
200 else {
201 dout.writeShort(0);
202 }
203
204 int size = mAttributes.size();
205 dout.writeShort(size);
206 for (int i=0; i<size; i++) {
207 Attribute attr = (Attribute)mAttributes.get(i);
208 attr.writeTo(dout);
209 }
210 }
211
212 static Attribute define(ConstantPool cp,
213 String name,
214 int length,
215 DataInput din,
216 AttributeFactory attrFactory)
217 throws IOException
218 {
219 CodeAttr code = new CodeAttr(cp);
220
221 final int maxStackDepth = din.readUnsignedShort();
222 final int maxLocals = din.readUnsignedShort();
223
224 final byte[] byteCodes = new byte[din.readInt()];
225 din.readFully(byteCodes);
226
227 int exceptionHandlerCount = din.readUnsignedShort();
228 final ExceptionHandler[] handlers =
229 new ExceptionHandler[exceptionHandlerCount];
230
231 for (int i=0; i<exceptionHandlerCount; i++) {
232 handlers[i] = ExceptionHandler.readFrom(cp, din);
233 }
234
235 code.mCodeBuffer = new CodeBuffer() {
236 public int getMaxStackDepth() {
237 return maxStackDepth;
238 }
239
240 public int getMaxLocals() {
241 return maxLocals;
242 }
243
244 public byte[] getByteCodes() {
245 return (byte[])byteCodes.clone();
246 }
247
248 public ExceptionHandler[] getExceptionHandlers() {
249 return (ExceptionHandler[])handlers.clone();
250 }
251 };
252
253 int attributeCount = din.readUnsignedShort();
254 for (int i=0; i<attributeCount; i++) {
255 code.addAttribute(Attribute.readFrom(cp, din, attrFactory));
256 }
257
258 return code;
259 }
260 }