| // Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| package com.android.tools.r8.utils; |
| |
| public abstract class BooleanLatticeElement { |
| |
| public static final BooleanLatticeElement BOTTOM = |
| new BooleanLatticeElement() { |
| |
| @Override |
| public OptionalBool asOptionalBool() { |
| throw new IllegalStateException("BooleanLatticeElement.BOTTOM is not an OptionalBool"); |
| } |
| |
| @Override |
| public boolean isBottom() { |
| return true; |
| } |
| |
| @Override |
| public String toString() { |
| return "bottom"; |
| } |
| }; |
| |
| BooleanLatticeElement() {} |
| |
| public abstract OptionalBool asOptionalBool(); |
| |
| public boolean isBottom() { |
| return false; |
| } |
| |
| public boolean isTrue() { |
| return false; |
| } |
| |
| public boolean isFalse() { |
| return false; |
| } |
| |
| public boolean isUnknown() { |
| return false; |
| } |
| |
| public boolean isPossiblyTrue() { |
| return isTrue() || isUnknown(); |
| } |
| |
| public boolean isPossiblyFalse() { |
| return isFalse() || isUnknown(); |
| } |
| |
| public BooleanLatticeElement join(BooleanLatticeElement other) { |
| if (this == other || other.isBottom() || isUnknown()) { |
| return this; |
| } |
| if (isBottom() || other.isUnknown()) { |
| return other; |
| } |
| assert isTrue() || isFalse(); |
| assert other.isTrue() || other.isFalse(); |
| return OptionalBool.UNKNOWN; |
| } |
| |
| @Override |
| public boolean equals(Object other) { |
| return this == other; |
| } |
| |
| @Override |
| public int hashCode() { |
| return System.identityHashCode(this); |
| } |
| |
| // Force all subtypes to implement toString(). |
| @Override |
| public abstract String toString(); |
| } |