| /* |
| * Copyright 2019 Google LLC |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package com.google.auto.factory.processor; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.collect.ImmutableSet; |
| import java.util.HashSet; |
| import java.util.Set; |
| import javax.lang.model.element.Element; |
| import javax.lang.model.type.ArrayType; |
| import javax.lang.model.type.DeclaredType; |
| import javax.lang.model.type.IntersectionType; |
| import javax.lang.model.type.TypeMirror; |
| import javax.lang.model.type.TypeVariable; |
| import javax.lang.model.type.UnionType; |
| import javax.lang.model.type.WildcardType; |
| import javax.lang.model.util.SimpleTypeVisitor8; |
| |
| final class TypeVariables { |
| private TypeVariables() {} |
| |
| static ImmutableSet<TypeVariable> getReferencedTypeVariables(TypeMirror type) { |
| checkNotNull(type); |
| return type.accept(ReferencedTypeVariables.INSTANCE, new HashSet<>()); |
| } |
| |
| private static final class ReferencedTypeVariables |
| extends SimpleTypeVisitor8<ImmutableSet<TypeVariable>, Set<Element>> { |
| |
| private static final ReferencedTypeVariables INSTANCE = new ReferencedTypeVariables(); |
| |
| ReferencedTypeVariables() { |
| super(ImmutableSet.of()); |
| } |
| |
| @Override |
| public ImmutableSet<TypeVariable> visitArray(ArrayType t, Set<Element> visited) { |
| return t.getComponentType().accept(this, visited); |
| } |
| |
| @Override |
| public ImmutableSet<TypeVariable> visitDeclared(DeclaredType t, Set<Element> visited) { |
| if (!visited.add(t.asElement())) { |
| return ImmutableSet.of(); |
| } |
| ImmutableSet.Builder<TypeVariable> typeVariables = ImmutableSet.builder(); |
| for (TypeMirror typeArgument : t.getTypeArguments()) { |
| typeVariables.addAll(typeArgument.accept(this, visited)); |
| } |
| return typeVariables.build(); |
| } |
| |
| @Override |
| public ImmutableSet<TypeVariable> visitTypeVariable(TypeVariable t, Set<Element> visited) { |
| if (!visited.add(t.asElement())) { |
| return ImmutableSet.of(); |
| } |
| ImmutableSet.Builder<TypeVariable> typeVariables = ImmutableSet.builder(); |
| typeVariables.add(t); |
| typeVariables.addAll(t.getLowerBound().accept(this, visited)); |
| typeVariables.addAll(t.getUpperBound().accept(this, visited)); |
| return typeVariables.build(); |
| } |
| |
| @Override |
| public ImmutableSet<TypeVariable> visitUnion(UnionType t, Set<Element> visited) { |
| ImmutableSet.Builder<TypeVariable> typeVariables = ImmutableSet.builder(); |
| for (TypeMirror unionType : t.getAlternatives()) { |
| typeVariables.addAll(unionType.accept(this, visited)); |
| } |
| return typeVariables.build(); |
| } |
| |
| @Override |
| public ImmutableSet<TypeVariable> visitIntersection(IntersectionType t, Set<Element> visited) { |
| ImmutableSet.Builder<TypeVariable> typeVariables = ImmutableSet.builder(); |
| for (TypeMirror intersectionType : t.getBounds()) { |
| typeVariables.addAll(intersectionType.accept(this, visited)); |
| } |
| return typeVariables.build(); |
| } |
| |
| @Override |
| public ImmutableSet<TypeVariable> visitWildcard(WildcardType t, Set<Element> visited) { |
| ImmutableSet.Builder<TypeVariable> typeVariables = ImmutableSet.builder(); |
| TypeMirror extendsBound = t.getExtendsBound(); |
| if (extendsBound != null) { |
| typeVariables.addAll(extendsBound.accept(this, visited)); |
| } |
| TypeMirror superBound = t.getSuperBound(); |
| if (superBound != null) { |
| typeVariables.addAll(superBound.accept(this, visited)); |
| } |
| return typeVariables.build(); |
| } |
| } |
| } |