J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| 13 | * accompanied this code). |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License version |
| 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 18 | * |
| 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 21 | * have any questions. |
| 22 | */ |
| 23 | |
| 24 | package ilib; |
| 25 | |
| 26 | class ClassReaderWriter implements RuntimeConstants { |
| 27 | |
| 28 | int codeAttributeIndex; |
| 29 | int lineNumberAttributeIndex; |
| 30 | int localVarAttributeIndex; |
| 31 | |
| 32 | private final byte[] orig; |
| 33 | private final byte[] gen; |
| 34 | private final int sectionLength; |
| 35 | |
| 36 | private static final int GROWTH_FACTOR = 2; |
| 37 | private static final int SECTIONS = 2; |
| 38 | private static final String codeAttributeName = "Code"; |
| 39 | private static final String lineNumberAttributeName = "LineNumberTable"; |
| 40 | private static final String localVarAttributeName = "LocalVariableTable"; |
| 41 | |
| 42 | private int[] genSectionPos = new int[SECTIONS]; |
| 43 | |
| 44 | private int inputPos = 0; |
| 45 | private int genPos = 0; |
| 46 | private int markPos = 0; |
| 47 | private int currentSection = 0; |
| 48 | |
| 49 | private String[] constantPool; |
| 50 | |
| 51 | ClassReaderWriter(byte[] orig) { |
| 52 | this.orig = orig; |
| 53 | sectionLength = orig.length * GROWTH_FACTOR; |
| 54 | gen = new byte[sectionLength * SECTIONS]; |
| 55 | for (int section = 0; section < SECTIONS; ++section) { |
| 56 | genSectionPos[section] = section * sectionLength; |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | int setSection(int section) { |
| 61 | int prevSection = currentSection; |
| 62 | genSectionPos[prevSection] = genPos; |
| 63 | genPos = genSectionPos[section]; |
| 64 | currentSection = section; |
| 65 | return prevSection; |
| 66 | } |
| 67 | |
| 68 | byte[] result() { |
| 69 | int section; |
| 70 | int totalLength = 0; |
| 71 | |
| 72 | setSection(0); // save current section |
| 73 | |
| 74 | for (section = 0; section < SECTIONS; ++section) { |
| 75 | int sectionStart = section * sectionLength; |
| 76 | int sectionGenLength = genSectionPos[section] - sectionStart; |
| 77 | totalLength += sectionGenLength; |
| 78 | } |
| 79 | |
| 80 | byte[] newcf = new byte[totalLength]; |
| 81 | int written = 0; |
| 82 | for (section = 0; section < SECTIONS; ++section) { |
| 83 | int sectionStart = section * sectionLength; |
| 84 | int sectionGenLength = genSectionPos[section] - sectionStart; |
| 85 | System.arraycopy(gen, sectionStart, newcf, written, sectionGenLength); |
| 86 | written += sectionGenLength; |
| 87 | } |
| 88 | |
| 89 | return newcf; |
| 90 | } |
| 91 | |
| 92 | int readU1() { |
| 93 | return ((int)orig[inputPos++]) & 0xFF; |
| 94 | } |
| 95 | |
| 96 | int readU2() { |
| 97 | int res = readU1(); |
| 98 | return (res << 8) + readU1(); |
| 99 | } |
| 100 | |
| 101 | short readS2() { |
| 102 | int res = readU1(); |
| 103 | return (short)((res << 8) + readU1()); |
| 104 | } |
| 105 | |
| 106 | int readU4() { |
| 107 | int res = readU2(); |
| 108 | return (res << 16) + readU2(); |
| 109 | } |
| 110 | |
| 111 | void writeU1(int val) { |
| 112 | gen[genPos++] = (byte)val; |
| 113 | } |
| 114 | |
| 115 | void writeU2(int val) { |
| 116 | writeU1(val >> 8); |
| 117 | writeU1(val & 0xFF); |
| 118 | } |
| 119 | |
| 120 | void writeU4(int val) { |
| 121 | writeU2(val >> 16); |
| 122 | writeU2(val & 0xFFFF); |
| 123 | } |
| 124 | |
| 125 | int copyU1() { |
| 126 | int value = readU1(); |
| 127 | writeU1(value); |
| 128 | return value; |
| 129 | } |
| 130 | |
| 131 | int copyU2() { |
| 132 | int value = readU2(); |
| 133 | writeU2(value); |
| 134 | return value; |
| 135 | } |
| 136 | |
| 137 | int copyU4() { |
| 138 | int value = readU4(); |
| 139 | writeU4(value); |
| 140 | return value; |
| 141 | } |
| 142 | |
| 143 | void copy(int count) { |
| 144 | for (int i = 0; i < count; ++i) { |
| 145 | gen[genPos++] = orig[inputPos++]; |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | void skip(int count) { |
| 150 | inputPos += count; |
| 151 | } |
| 152 | |
| 153 | byte[] readBytes(int count) { |
| 154 | byte[] bytes = new byte[count]; |
| 155 | for (int i = 0; i < count; ++i) { |
| 156 | bytes[i] = orig[inputPos++]; |
| 157 | } |
| 158 | return bytes; |
| 159 | } |
| 160 | |
| 161 | void writeBytes(byte[] bytes) { |
| 162 | for (int i = 0; i < bytes.length; ++i) { |
| 163 | gen[genPos++] = bytes[i]; |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | byte[] inputBytes() { |
| 168 | return orig; |
| 169 | } |
| 170 | |
| 171 | int inputPosition() { |
| 172 | return inputPos; |
| 173 | } |
| 174 | |
| 175 | void setInputPosition(int pos) { |
| 176 | inputPos = pos; |
| 177 | } |
| 178 | |
| 179 | void markLocalPositionStart() { |
| 180 | markPos = inputPos; |
| 181 | } |
| 182 | |
| 183 | int localPosition() { |
| 184 | return inputPos - markPos; |
| 185 | } |
| 186 | |
| 187 | void rewind() { |
| 188 | setInputPosition(markPos); |
| 189 | } |
| 190 | |
| 191 | int generatedPosition() { |
| 192 | return genPos; |
| 193 | } |
| 194 | |
| 195 | void randomAccessWriteU2(int pos, int val) { |
| 196 | int savePos = genPos; |
| 197 | genPos = pos; |
| 198 | writeU2(val); |
| 199 | genPos = savePos; |
| 200 | } |
| 201 | |
| 202 | void randomAccessWriteU4(int pos, int val) { |
| 203 | int savePos = genPos; |
| 204 | genPos = pos; |
| 205 | writeU4(val); |
| 206 | genPos = savePos; |
| 207 | } |
| 208 | |
| 209 | String constantPoolString(int index) { |
| 210 | return constantPool[index]; |
| 211 | } |
| 212 | |
| 213 | void copyConstantPool(int constantPoolCount){ |
| 214 | // copy const pool |
| 215 | constantPool = new String[constantPoolCount]; |
| 216 | // index zero not in class file |
| 217 | for (int i = 1; i < constantPoolCount; ++i) { |
| 218 | int tag = readU1(); |
| 219 | writeU1(tag); |
| 220 | switch (tag) { |
| 221 | case CONSTANT_CLASS: |
| 222 | case CONSTANT_STRING: |
| 223 | copy(2); |
| 224 | break; |
| 225 | case CONSTANT_FIELD: |
| 226 | case CONSTANT_METHOD: |
| 227 | case CONSTANT_INTERFACEMETHOD: |
| 228 | case CONSTANT_INTEGER: |
| 229 | case CONSTANT_FLOAT: |
| 230 | case CONSTANT_NAMEANDTYPE: |
| 231 | copy(4); |
| 232 | break; |
| 233 | case CONSTANT_LONG: |
| 234 | case CONSTANT_DOUBLE: |
| 235 | copy(8); |
| 236 | ++i; // these take two CP entries - duh! |
| 237 | break; |
| 238 | case CONSTANT_UTF8: |
| 239 | int len = copyU2(); |
| 240 | byte[] utf8 = readBytes(len); |
| 241 | String str = null; // null to shut the compiler up |
| 242 | try { |
| 243 | str = new String(utf8, "UTF-8"); |
| 244 | } catch (Exception exc) { |
| 245 | throw new Error("CP exception: " + exc); |
| 246 | } |
| 247 | constantPool[i] = str; |
| 248 | if (str.equals(codeAttributeName)) { |
| 249 | codeAttributeIndex = i; |
| 250 | } else if (str.equals(lineNumberAttributeName)) { |
| 251 | lineNumberAttributeIndex = i; |
| 252 | } else if (str.equals(localVarAttributeName)) { |
| 253 | localVarAttributeIndex = i; |
| 254 | } |
| 255 | writeBytes(utf8); |
| 256 | break; |
| 257 | default: |
| 258 | throw new Error(i + " unexpected CP tag: " + tag); |
| 259 | } |
| 260 | } |
| 261 | } |
| 262 | |
| 263 | } |