1 /* 2 * Copyright (c) 2009, 2016, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package jdk.vm.ci.meta; 24 25 /** 26 * Abstract base class for values. 27 */ 28 public abstract class Value { 29 30 public static final Value[] NO_VALUES = new Value[0]; 31 32 public static final AllocatableValue ILLEGAL = new IllegalValue(); 33 34 private static final class IllegalValue extends AllocatableValue { 35 private IllegalValue() { 36 super(ValueKind.Illegal); 37 } 38 39 @Override 40 public String toString() { 41 return "-"; 42 } 43 44 @Override 45 public boolean equals(Object other) { 46 // Due to de-serialization this object may exist multiple times. So we compare classes 47 // instead of the individual objects. (This anonymous class has always the same meaning) 48 return other instanceof IllegalValue; 49 } 50 } 51 52 private final ValueKind<?> valueKind; 53 54 /** 55 * Initializes a new value of the specified kind. 56 * 57 * @param valueKind the kind 58 */ 59 protected Value(ValueKind<?> valueKind) { 60 this.valueKind = valueKind; 61 } 62 63 /** 64 * Returns a String representation of the kind, which should be the end of all 65 * {@link #toString()} implementation of subclasses. 66 */ 67 protected final String getKindSuffix() { 68 return "|" + valueKind.getKindSuffix(); 69 } 70 71 public final ValueKind<?> getValueKind() { 72 return valueKind; 73 } 74 75 public final <K extends ValueKind<K>> K getValueKind(Class<K> cls) { 76 return cls.cast(valueKind); 77 } 78 79 /** 80 * Returns the platform specific kind used to store this value. 81 */ 82 public final PlatformKind getPlatformKind() { 83 return valueKind.getPlatformKind(); 84 } 85 86 @Override 87 public int hashCode() { 88 return 41 + valueKind.hashCode(); 89 } 90 91 @Override 92 public boolean equals(Object obj) { 93 if (obj instanceof Value) { 94 Value that = (Value) obj; 95 return valueKind.equals(that.valueKind); 96 } 97 return false; 98 } 99 100 /** 101 * Checks if this value is identical to {@code other}. 102 * 103 * Warning: Use with caution! Usually equivalence {@link #equals(Object)} is sufficient and 104 * should be used. 105 */ 106 public final boolean identityEquals(Value other) { 107 return this == other; 108 } 109 }