1 /* 2 * Copyright (c) 2014, 2018, 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 @Override 40 public void accept(Visitor v) { 41 v.visitBoolean(nonNull); 42 v.visitBoolean(alwaysNull); 43 } 44 45 protected AbstractPointerStamp(boolean nonNull, boolean alwaysNull) { 46 this.nonNull = nonNull; 47 this.alwaysNull = alwaysNull; 48 } 49 50 public boolean nonNull() { 51 assert !this.isEmpty() || nonNull; 52 return nonNull; 53 } 54 55 public boolean alwaysNull() { 56 return alwaysNull; 57 } 58 59 protected abstract AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull); 60 61 @Override 62 public int hashCode() { 63 final int prime = 31; 64 int result = 1; 65 result = prime * result + (alwaysNull ? 1231 : 1237); 66 result = prime * result + (nonNull ? 1231 : 1237); 67 return result; 68 } 69 70 protected Stamp defaultPointerJoin(Stamp stamp) { 71 assert getClass() == stamp.getClass(); 72 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 73 boolean joinNonNull = this.nonNull || other.nonNull; 74 boolean joinAlwaysNull = this.alwaysNull || other.alwaysNull; 75 if (joinNonNull && joinAlwaysNull) { 76 return empty(); 77 } else { 78 return copyWith(joinNonNull, joinAlwaysNull); 79 } 80 } 81 82 @Override 83 public Stamp improveWith(Stamp other) { 84 return join(other); 85 } 86 87 @Override 88 public Stamp meet(Stamp stamp) { 89 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 90 boolean meetNonNull = this.nonNull && other.nonNull; 91 boolean meetAlwaysNull = this.alwaysNull && other.alwaysNull; 92 return copyWith(meetNonNull, meetAlwaysNull); 93 } 94 95 @Override 96 public Stamp unrestricted() { 97 return copyWith(false, false); 98 } 99 100 public static Stamp pointerNonNull(Stamp stamp) { 101 AbstractPointerStamp pointer = (AbstractPointerStamp) stamp; 102 return pointer.asNonNull(); 103 } 104 105 public static Stamp pointerMaybeNull(Stamp stamp) { 106 AbstractPointerStamp pointer = (AbstractPointerStamp) stamp; 107 return pointer.asMaybeNull(); 108 } 109 110 public static Stamp pointerAlwaysNull(Stamp stamp) { 111 AbstractPointerStamp pointer = (AbstractPointerStamp) stamp; 112 return pointer.asAlwaysNull(); 113 } 114 115 public Stamp asNonNull() { 116 if (isEmpty()) { 117 return this; 118 } 119 return copyWith(true, false); 120 } 121 122 public Stamp asMaybeNull() { 123 if (isEmpty()) { 124 return this; 125 } 126 return copyWith(false, false); 127 } 128 129 public Stamp asAlwaysNull() { 130 if (isEmpty()) { 131 return this; 132 } 133 return copyWith(false, true); 134 } 135 136 @Override 137 public boolean equals(Object obj) { 138 if (this == obj) { 139 return true; 140 } 141 if (obj == null || getClass() != obj.getClass()) { 142 return false; 143 } 144 AbstractPointerStamp other = (AbstractPointerStamp) obj; 145 return this.alwaysNull == other.alwaysNull && this.nonNull == other.nonNull; 146 } 147 148 @Override 149 public Constant asConstant() { 150 if (alwaysNull) { 151 return nullConstant(); 152 } 153 return super.asConstant(); 154 } 155 156 public JavaConstant nullConstant() { 157 return JavaConstant.NULL_POINTER; 158 } 159 160 @Override 161 public JavaKind getStackKind() { 162 return JavaKind.Illegal; 163 } 164 }