1 /* 2 * Copyright (c) 2014, 2015, 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 24 25 package org.graalvm.compiler.core.common.type; 26 27 import jdk.vm.ci.meta.Constant; 28 import jdk.vm.ci.meta.JavaConstant; 29 import jdk.vm.ci.meta.JavaKind; 30 31 /** 32 * Abstract base class of all pointer types. 33 */ 34 public abstract class AbstractPointerStamp extends Stamp { 35 36 private final boolean nonNull; 37 private final boolean alwaysNull; 38 39 protected AbstractPointerStamp(boolean nonNull, boolean alwaysNull) { 40 this.nonNull = nonNull; 41 this.alwaysNull = alwaysNull; 42 } 43 44 public boolean nonNull() { 45 assert !this.isEmpty() || nonNull; 46 return nonNull; 47 } 48 49 public boolean alwaysNull() { 50 return alwaysNull; 51 } 52 53 protected abstract AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull); 54 55 @Override 56 public int hashCode() { 57 final int prime = 31; 58 int result = 1; 59 result = prime * result + (alwaysNull ? 1231 : 1237); 60 result = prime * result + (nonNull ? 1231 : 1237); 61 return result; 62 } 63 64 protected Stamp defaultPointerJoin(Stamp stamp) { 65 assert getClass() == stamp.getClass(); 66 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 67 boolean joinNonNull = this.nonNull || other.nonNull; 68 boolean joinAlwaysNull = this.alwaysNull || other.alwaysNull; 69 if (joinNonNull && joinAlwaysNull) { 70 return empty(); 71 } else { 72 return copyWith(joinNonNull, joinAlwaysNull); 73 } 74 } 75 76 @Override 77 public Stamp improveWith(Stamp other) { 78 return join(other); 79 } 80 81 @Override 82 public Stamp meet(Stamp stamp) { 83 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 84 boolean meetNonNull = this.nonNull && other.nonNull; 85 boolean meetAlwaysNull = this.alwaysNull && other.alwaysNull; 86 return copyWith(meetNonNull, meetAlwaysNull); 87 } 88 89 @Override 90 public Stamp unrestricted() { 91 return copyWith(false, false); 92 } 93 94 public static Stamp pointerNonNull(Stamp stamp) { 95 AbstractPointerStamp pointer = (AbstractPointerStamp) stamp; 96 return pointer.asNonNull(); 97 } 98 99 public static Stamp pointerMaybeNull(Stamp stamp) { 100 AbstractPointerStamp pointer = (AbstractPointerStamp) stamp; 101 return pointer.asMaybeNull(); 102 } 103 104 public static Stamp pointerAlwaysNull(Stamp stamp) { 105 AbstractPointerStamp pointer = (AbstractPointerStamp) stamp; 106 return pointer.asAlwaysNull(); 107 } 108 109 public Stamp asNonNull() { 110 if (isEmpty()) { 111 return this; 112 } 113 return copyWith(true, false); 114 } 115 116 public Stamp asMaybeNull() { 117 if (isEmpty()) { 118 return this; 119 } 120 return copyWith(false, false); 121 } 122 123 public Stamp asAlwaysNull() { 124 if (isEmpty()) { 125 return this; 126 } 127 return copyWith(false, true); 128 } 129 130 @Override 131 public boolean equals(Object obj) { 132 if (this == obj) { 133 return true; 134 } 135 if (obj == null || getClass() != obj.getClass()) { 136 return false; 137 } 138 AbstractPointerStamp other = (AbstractPointerStamp) obj; 139 return this.alwaysNull == other.alwaysNull && this.nonNull == other.nonNull; 140 } 141 142 @Override 143 public Constant asConstant() { 144 if (alwaysNull) { 145 return JavaConstant.NULL_POINTER; 146 } else { 147 return null; 148 } 149 } 150 151 @Override 152 public JavaKind getStackKind() { 153 return JavaKind.Illegal; 154 } 155 }