| /******************************************************************************* |
| * Copyright (c) 2013, 2015 GK Software AG. |
| * 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 |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.compiler.lookup; |
| |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.eclipse.jdt.core.compiler.CharOperation; |
| |
| /** |
| * Implementation of 18.1.1 in JLS8 |
| */ |
| public class InferenceVariable extends TypeVariableBinding { |
| |
| /** Structured key for interning. */ |
| static class InferenceVarKey { |
| /*@NonNull*/ TypeBinding typeParameter; |
| long position; |
| int rank; |
| InferenceVarKey(TypeBinding typeParameter, InvocationSite site, int rank) { |
| this.typeParameter = typeParameter; |
| this.position = ((long) site.sourceStart() << 32) + site.sourceEnd(); |
| this.rank = rank; |
| } |
| @Override |
| public int hashCode() { |
| final int prime = 31; |
| int result = 1; |
| result = prime * result + (int) (this.position ^ (this.position >>> 32)); |
| result = prime * result + this.rank; |
| result = prime * result + this.typeParameter.id; |
| return result; |
| } |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) |
| return true; |
| if (obj == null) |
| return false; |
| if (!(obj instanceof InferenceVarKey)) |
| return false; |
| InferenceVarKey other = (InferenceVarKey) obj; |
| if (this.position != other.position) |
| return false; |
| if (this.rank != other.rank) |
| return false; |
| if (TypeBinding.notEquals(this.typeParameter, other.typeParameter)) |
| return false; |
| return true; |
| } |
| } |
| |
| /** |
| * Create or retrieve the inference variable representing the given typeParameter. |
| * Inference variables are interned to avoid duplication due to lambda copying. |
| */ |
| public static InferenceVariable get(TypeBinding typeParameter, int rank, InvocationSite site, Scope scope, ReferenceBinding object) { |
| Map<InferenceVarKey, InferenceVariable> uniqueInferenceVariables = scope.compilationUnitScope().uniqueInferenceVariables; |
| InferenceVariable var = null; |
| InferenceVarKey key = null; |
| if (site != null && typeParameter != null) { |
| key = new InferenceVarKey(typeParameter, site, rank); |
| var = uniqueInferenceVariables.get(key); |
| } |
| if (var == null) { |
| int newVarId = uniqueInferenceVariables.size(); |
| var = new InferenceVariable(typeParameter, rank, newVarId, site, scope.environment(), object); |
| if (key != null) |
| uniqueInferenceVariables.put(key, var); |
| } |
| return var; |
| } |
| |
| |
| InvocationSite site; |
| TypeBinding typeParameter; |
| long nullHints; // one of TagBits.{AnnotationNonNull,AnnotationNullable} may steer inference into inferring nullness as well; set both bits to request avoidance. |
| private InferenceVariable prototype; |
| int varId; // this is used for constructing a source name like T#0. |
| |
| private InferenceVariable(TypeBinding typeParameter, int parameterRank, int iVarId, InvocationSite site, LookupEnvironment environment, ReferenceBinding object) { |
| this(typeParameter, parameterRank, site, makeName(typeParameter, iVarId), environment, object); |
| this.varId = iVarId; |
| } |
| private static char[] makeName(TypeBinding typeParameter, int iVarId) { |
| if (typeParameter.getClass() == TypeVariableBinding.class) { |
| return CharOperation.concat(typeParameter.shortReadableName(), Integer.toString(iVarId).toCharArray(), '#'); |
| } |
| return CharOperation.concat( |
| CharOperation.concat('(', typeParameter.shortReadableName(), ')'), |
| Integer.toString(iVarId).toCharArray(), '#'); |
| } |
| private InferenceVariable(TypeBinding typeParameter, int parameterRank, InvocationSite site, char[] sourceName, LookupEnvironment environment, ReferenceBinding object) { |
| super(sourceName, null/*declaringElement*/, parameterRank, environment); |
| this.site = site; |
| this.typeParameter = typeParameter; |
| this.tagBits |= typeParameter.tagBits & TagBits.AnnotationNullMASK; |
| if (typeParameter.isTypeVariable()) { |
| TypeVariableBinding typeVariable = (TypeVariableBinding) typeParameter; |
| if (typeVariable.firstBound != null) { |
| long boundBits = typeVariable.firstBound.tagBits & TagBits.AnnotationNullMASK; |
| if (boundBits == TagBits.AnnotationNonNull) |
| this.tagBits |= boundBits; // @NonNull must be preserved |
| else |
| this.nullHints |= boundBits; // @Nullable is only a hint |
| } |
| } |
| this.superclass = object; |
| this.prototype = this; |
| } |
| |
| @Override |
| public TypeBinding clone(TypeBinding enclosingType) { |
| InferenceVariable clone = new InferenceVariable(this.typeParameter, this.rank, this.site, this.sourceName, this.environment, this.superclass); |
| clone.tagBits = this.tagBits; |
| clone.nullHints = this.nullHints; |
| clone.varId = this.varId; |
| clone.prototype = this; |
| return clone; |
| } |
| |
| @Override |
| public InferenceVariable prototype() { |
| return this.prototype; |
| } |
| |
| @Override |
| public char[] constantPoolName() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public PackageBinding getPackage() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean isCompatibleWith(TypeBinding right, Scope scope) { |
| // if inference variables are ever checked for compatibility |
| // (like during inner resolve of a ReferenceExpression during inference) |
| // treat it as a wildcard, compatible with any any and every type. |
| return true; |
| } |
| |
| @Override |
| public boolean isProperType(boolean admitCapture18) { |
| return false; |
| } |
| |
| //{ObjectTeams: cross the OT package, make protected: |
| @Override |
| protected |
| // SH} |
| TypeBinding substituteInferenceVariable(InferenceVariable var, TypeBinding substituteType) { |
| if (TypeBinding.equalsEquals(this, var)) |
| return substituteType; |
| return this; |
| } |
| |
| //{ObjectTeams: cross the OT package, make protected: |
| @Override |
| protected |
| // SH} |
| void collectInferenceVariables(Set<InferenceVariable> variables) { |
| variables.add(this); |
| } |
| |
| @Override |
| public ReferenceBinding[] superInterfaces() { |
| return Binding.NO_SUPERINTERFACES; |
| } |
| |
| @Override |
| public char[] qualifiedSourceName() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public char[] sourceName() { |
| return this.sourceName; |
| } |
| |
| @Override |
| public char[] readableName() { |
| return this.sourceName; |
| } |
| |
| @Override |
| public boolean hasTypeBit(int bit) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public String debugName() { |
| return String.valueOf(this.sourceName); |
| } |
| |
| @Override |
| public String toString() { |
| return debugName(); |
| } |
| |
| @Override |
| public int hashCode() { |
| int code = this.typeParameter.hashCode() + 17 * this.rank; |
| if (this.site != null) { |
| code = 31 * code + this.site.sourceStart(); |
| code = 31 * code + this.site.sourceEnd(); |
| } |
| return code; |
| } |
| @Override |
| public boolean equals(Object obj) { |
| if (!(obj instanceof InferenceVariable)) |
| return false; |
| InferenceVariable other = (InferenceVariable) obj; |
| return this.rank == other.rank |
| && InferenceContext18.isSameSite(this.site, other.site) |
| && TypeBinding.equalsEquals(this.typeParameter, other.typeParameter); |
| } |
| |
| @Override |
| public TypeBinding erasure() { |
| // lazily initialize field that may be required in super.erasure(): |
| if (this.superclass == null) |
| this.superclass = this.environment.getType(TypeConstants.JAVA_LANG_OBJECT); |
| return super.erasure(); |
| } |
| } |