1 /* 2 * ProGuard -- shrinking, optimization, obfuscation, and preverification 3 * of Java bytecode. 4 * 5 * Copyright (c) 2002-2013 Eric Lafortune (eric (at) graphics.cornell.edu) 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the Free 9 * Software Foundation; either version 2 of the License, or (at your option) 10 * any later version. 11 * 12 * This program is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 * more details. 16 * 17 * You should have received a copy of the GNU General Public License along 18 * with this program; if not, write to the Free Software Foundation, Inc., 19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 package proguard.evaluation.value; 22 23 /** 24 * This abstract class represents a partially evaluated value. 25 * 26 * @author Eric Lafortune 27 */ 28 public abstract class Value 29 { 30 public static final int NEVER = -1; 31 public static final int MAYBE = 0; 32 public static final int ALWAYS = 1; 33 34 public static final int TYPE_INTEGER = 1; 35 public static final int TYPE_LONG = 2; 36 public static final int TYPE_FLOAT = 3; 37 public static final int TYPE_DOUBLE = 4; 38 public static final int TYPE_REFERENCE = 5; 39 public static final int TYPE_INSTRUCTION_OFFSET = 6; 40 public static final int TYPE_TOP = 7; 41 42 43 /** 44 * Returns this Value as a Category1Value. 45 */ 46 public Category1Value category1Value() 47 { 48 throw new IllegalArgumentException("Value is not a Category 1 value [" + this.getClass().getName() + "]"); 49 } 50 51 /** 52 * Returns this Value as a Category2Value. 53 */ 54 public Category2Value category2Value() 55 { 56 throw new IllegalArgumentException("Value is not a Category 2 value [" + this.getClass().getName() + "]"); 57 } 58 59 60 /** 61 * Returns this Value as an IntegerValue. 62 */ 63 public IntegerValue integerValue() 64 { 65 throw new IllegalArgumentException("Value is not an integer value [" + this.getClass().getName() + "]"); 66 } 67 68 /** 69 * Returns this Value as a LongValue. 70 */ 71 public LongValue longValue() 72 { 73 throw new IllegalArgumentException("Value is not a long value [" + this.getClass().getName() + "]"); 74 } 75 76 /** 77 * Returns this Value as a FloatValue. 78 */ 79 public FloatValue floatValue() 80 { 81 throw new IllegalArgumentException("Value is not a float value [" + this.getClass().getName() + "]"); 82 } 83 84 /** 85 * Returns this Value as a DoubleValue. 86 */ 87 public DoubleValue doubleValue() 88 { 89 throw new IllegalArgumentException("Value is not a double value [" + this.getClass().getName() + "]"); 90 } 91 92 /** 93 * Returns this Value as a ReferenceValue. 94 */ 95 public ReferenceValue referenceValue() 96 { 97 throw new IllegalArgumentException("Value is not a reference value [" + this.getClass().getName() + "]"); 98 } 99 100 /** 101 * Returns this Value as an InstructionOffsetValue. 102 */ 103 public InstructionOffsetValue instructionOffsetValue() 104 { 105 throw new IllegalArgumentException("Value is not an instruction offset value [" + this.getClass().getName() + "]"); 106 } 107 108 109 /** 110 * Returns whether this Value represents a single specific (but possibly 111 * unknown) value. 112 */ 113 public boolean isSpecific() 114 { 115 return false; 116 } 117 118 119 /** 120 * Returns whether this Value represents a single particular (known) 121 * value. 122 */ 123 public boolean isParticular() 124 { 125 return false; 126 } 127 128 129 /** 130 * Returns the generalization of this Value and the given other Value. 131 */ 132 public abstract Value generalize(Value other); 133 134 135 /** 136 * Returns whether the computational type of this Value is a category 2 type. 137 * This means that it takes up the space of two category 1 types on the 138 * stack, for instance. 139 */ 140 public abstract boolean isCategory2(); 141 142 143 /** 144 * Returns the computational type of this Value. 145 * @return <code>TYPE_INTEGER</code>, 146 * <code>TYPE_LONG</code>, 147 * <code>TYPE_FLOAT</code>, 148 * <code>TYPE_DOUBLE</code>, 149 * <code>TYPE_REFERENCE</code>, or 150 * <code>TYPE_INSTRUCTION_OFFSET</code>. 151 */ 152 public abstract int computationalType(); 153 154 155 /** 156 * Returns the internal type of this Value. 157 * @return <code>ClassConstants.INTERNAL_TYPE_BOOLEAN</code>, 158 * <code>ClassConstants.INTERNAL_TYPE_BYTE</code>, 159 * <code>ClassConstants.INTERNAL_TYPE_CHAR</code>, 160 * <code>ClassConstants.INTERNAL_TYPE_SHORT</code>, 161 * <code>ClassConstants.INTERNAL_TYPE_INT</code>, 162 * <code>ClassConstants.INTERNAL_TYPE_LONG</code>, 163 * <code>ClassConstants.INTERNAL_TYPE_FLOAT</code>, 164 * <code>ClassConstants.INTERNAL_TYPE_DOUBLE</code>, 165 * <code>ClassConstants.INTERNAL_TYPE_CLASS_START ... ClassConstants.INTERNAL_TYPE_CLASS_END</code>, or 166 * an array type containing any of these types (always as String). 167 */ 168 public abstract String internalType(); 169 } 170
