1 /*** 2 * ASM: a very small and fast Java bytecode manipulation framework 3 * Copyright (c) 2000-2005 INRIA, France Telecom 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the copyright holders nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND 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 COPYRIGHT OWNER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 28 * THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 package org.objectweb.asm; 31 32 /** 33 * A constant pool item. Constant pool items can be created with the 'newXXX' 34 * methods in the {@link ClassWriter} class. 35 * 36 * @author Eric Bruneton 37 */ 38 final class Item { 39 40 /** 41 * Index of this item in the constant pool. 42 */ 43 int index; 44 45 /** 46 * Type of this constant pool item. A single class is used to represent all 47 * constant pool item types, in order to minimize the bytecode size of this 48 * package. The value of this field is one of {@link ClassWriter#INT}, 49 * {@link ClassWriter#LONG}, {@link ClassWriter#FLOAT}, 50 * {@link ClassWriter#DOUBLE}, {@link ClassWriter#UTF8}, 51 * {@link ClassWriter#STR}, {@link ClassWriter#CLASS}, 52 * {@link ClassWriter#NAME_TYPE}, {@link ClassWriter#FIELD}, 53 * {@link ClassWriter#METH}, {@link ClassWriter#IMETH}. 54 */ 55 int type; 56 57 /** 58 * Value of this item, for an integer item. 59 */ 60 int intVal; 61 62 /** 63 * Value of this item, for a long item. 64 */ 65 long longVal; 66 67 /** 68 * Value of this item, for a float item. 69 */ 70 float floatVal; 71 72 /** 73 * Value of this item, for a double item. 74 */ 75 double doubleVal; 76 77 /** 78 * First part of the value of this item, for items that do not hold a 79 * primitive value. 80 */ 81 String strVal1; 82 83 /** 84 * Second part of the value of this item, for items that do not hold a 85 * primitive value. 86 */ 87 String strVal2; 88 89 /** 90 * Third part of the value of this item, for items that do not hold a 91 * primitive value. 92 */ 93 String strVal3; 94 95 /** 96 * The hash code value of this constant pool item. 97 */ 98 int hashCode; 99 100 /** 101 * Link to another constant pool item, used for collision lists in the 102 * constant pool's hash table. 103 */ 104 Item next; 105 106 /** 107 * Constructs an uninitialized {@link Item}. 108 */ Item()109 Item() { 110 } 111 Item(int index)112 Item(int index) { 113 this.index = index; 114 } 115 116 /** 117 * Constructs a copy of the given item. 118 * 119 * @param index index of the item to be constructed. 120 * @param i the item that must be copied into the item to be constructed. 121 */ Item(final int index, final Item i)122 Item(final int index, final Item i) { 123 this.index = index; 124 type = i.type; 125 intVal = i.intVal; 126 longVal = i.longVal; 127 floatVal = i.floatVal; 128 doubleVal = i.doubleVal; 129 strVal1 = i.strVal1; 130 strVal2 = i.strVal2; 131 strVal3 = i.strVal3; 132 hashCode = i.hashCode; 133 } 134 135 /** 136 * Sets this item to an integer item. 137 * 138 * @param intVal the value of this item. 139 */ set(final int intVal)140 void set(final int intVal) { 141 this.type = ClassWriter.INT; 142 this.intVal = intVal; 143 this.hashCode = 0x7FFFFFFF & (type + intVal); 144 } 145 146 /** 147 * Sets this item to a long item. 148 * 149 * @param longVal the value of this item. 150 */ set(final long longVal)151 void set(final long longVal) { 152 this.type = ClassWriter.LONG; 153 this.longVal = longVal; 154 this.hashCode = 0x7FFFFFFF & (type + (int) longVal); 155 } 156 157 /** 158 * Sets this item to a float item. 159 * 160 * @param floatVal the value of this item. 161 */ set(final float floatVal)162 void set(final float floatVal) { 163 this.type = ClassWriter.FLOAT; 164 this.floatVal = floatVal; 165 this.hashCode = 0x7FFFFFFF & (type + (int) floatVal); 166 } 167 168 /** 169 * Sets this item to a double item. 170 * 171 * @param doubleVal the value of this item. 172 */ set(final double doubleVal)173 void set(final double doubleVal) { 174 this.type = ClassWriter.DOUBLE; 175 this.doubleVal = doubleVal; 176 this.hashCode = 0x7FFFFFFF & (type + (int) doubleVal); 177 } 178 179 /** 180 * Sets this item to an item that do not hold a primitive value. 181 * 182 * @param type the type of this item. 183 * @param strVal1 first part of the value of this item. 184 * @param strVal2 second part of the value of this item. 185 * @param strVal3 third part of the value of this item. 186 */ set( final int type, final String strVal1, final String strVal2, final String strVal3)187 void set( 188 final int type, 189 final String strVal1, 190 final String strVal2, 191 final String strVal3) 192 { 193 this.type = type; 194 this.strVal1 = strVal1; 195 this.strVal2 = strVal2; 196 this.strVal3 = strVal3; 197 switch (type) { 198 case ClassWriter.UTF8: 199 case ClassWriter.STR: 200 case ClassWriter.CLASS: 201 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()); 202 return; 203 case ClassWriter.NAME_TYPE: 204 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode() 205 * strVal2.hashCode()); 206 return; 207 // ClassWriter.FIELD: 208 // ClassWriter.METH: 209 // ClassWriter.IMETH: 210 default: 211 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode() 212 * strVal2.hashCode() * strVal3.hashCode()); 213 } 214 } 215 216 /** 217 * Indicates if the given item is equal to this one. 218 * 219 * @param i the item to be compared to this one. 220 * @return <tt>true</tt> if the given item if equal to this one, 221 * <tt>false</tt> otherwise. 222 */ isEqualTo(final Item i)223 boolean isEqualTo(final Item i) { 224 if (i.type == type) { 225 switch (type) { 226 case ClassWriter.INT: 227 return i.intVal == intVal; 228 case ClassWriter.LONG: 229 return i.longVal == longVal; 230 case ClassWriter.FLOAT: 231 return i.floatVal == floatVal; 232 case ClassWriter.DOUBLE: 233 return i.doubleVal == doubleVal; 234 case ClassWriter.UTF8: 235 case ClassWriter.STR: 236 case ClassWriter.CLASS: 237 return i.strVal1.equals(strVal1); 238 case ClassWriter.NAME_TYPE: 239 return i.strVal1.equals(strVal1) 240 && i.strVal2.equals(strVal2); 241 // ClassWriter.FIELD: 242 // ClassWriter.METH: 243 // ClassWriter.IMETH: 244 default: 245 return i.strVal1.equals(strVal1) 246 && i.strVal2.equals(strVal2) 247 && i.strVal3.equals(strVal3); 248 } 249 } 250 return false; 251 } 252 } 253