| /******************************************************************************* |
| * Copyright (c) 2013, 2018 GK Software AG and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Stephan Herrmann - initial API and implementation |
| * IBM Corporation - bug fixes |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.compiler.lookup; |
| |
| |
| /** |
| * Implementation of 18.1.3 in JLS8 |
| */ |
| public class TypeBound extends ReductionResult { |
| |
| InferenceVariable left; |
| |
| // this flag contributes to the workaround controlled by InferenceContext18.ARGUMENT_CONSTRAINTS_ARE_SOFT: |
| boolean isSoft; |
| |
| // here we accumulate null tagBits from any types that have been related to this type bound during incorporation: |
| long nullHints; |
| |
| static TypeBound createBoundOrDependency(InferenceSubstitution theta, TypeBinding type, InferenceVariable variable) { |
| // Part of JLS8 sect 18.1.3: |
| return new TypeBound(variable, theta.substitute(theta, type), SUBTYPE, true); |
| } |
| |
| /** Create a true type bound or a dependency. */ |
| TypeBound(InferenceVariable inferenceVariable, TypeBinding typeBinding, int relation) { |
| this(inferenceVariable, typeBinding, relation, false); |
| } |
| |
| TypeBound(InferenceVariable inferenceVariable, TypeBinding typeBinding, int relation, boolean isSoft) { |
| this.left = inferenceVariable; |
| this.right = typeBinding; |
| if (((inferenceVariable.tagBits | this.right.tagBits) & TagBits.AnnotationNullMASK) != 0) { |
| if ((inferenceVariable.tagBits & TagBits.AnnotationNullMASK) == (this.right.tagBits & TagBits.AnnotationNullMASK)) { |
| // strip off identical nullness on both sides: |
| this.left = (InferenceVariable) inferenceVariable.withoutToplevelNullAnnotation(); |
| this.right = this.right.withoutToplevelNullAnnotation(); |
| } else { |
| long mask = 0; |
| // extract hint, e.g.: T#0 <: @NonNull Right => T#0 hinted as @NonNull |
| switch (relation) { |
| case SAME: mask = TagBits.AnnotationNullMASK; break; |
| case SUBTYPE: mask = TagBits.AnnotationNonNull; break; // sub of @Nullable is irrelevant |
| case SUPERTYPE: mask = TagBits.AnnotationNullable; break; // super of @NonNull is irrelevant |
| } |
| inferenceVariable.prototype().nullHints |= this.right.tagBits & mask; |
| } |
| } |
| this.relation = relation; |
| this.isSoft = isSoft; |
| } |
| |
| /** distinguish bounds from dependencies. */ |
| boolean isBound() { |
| return this.right.isProperType(true); |
| } |
| |
| @Override |
| public int hashCode() { |
| return this.left.hashCode() + this.right.hashCode() + this.relation; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj instanceof TypeBound) { |
| TypeBound other = (TypeBound) obj; |
| return (this.relation == other.relation) && TypeBinding.equalsEquals(this.left, other.left) && TypeBinding.equalsEquals(this.right, other.right); |
| } |
| return false; |
| } |
| |
| // debugging: |
| @Override |
| public String toString() { |
| boolean isBound = this.right.isProperType(true); |
| StringBuffer buf = new StringBuffer(); |
| buf.append(isBound ? "TypeBound " : "Dependency "); //$NON-NLS-1$ //$NON-NLS-2$ |
| buf.append(this.left.sourceName); |
| buf.append(relationToString(this.relation)); |
| buf.append(this.right.readableName()); |
| return buf.toString(); |
| } |
| } |