1 /* 2 * Copyright (C) 2018 The Dagger Authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package dagger.internal.codegen; 18 19 import static com.google.common.base.Preconditions.checkNotNull; 20 21 import com.google.auto.common.BasicAnnotationProcessor.ProcessingStep; 22 import com.google.common.collect.ImmutableSet; 23 import com.google.common.collect.ImmutableSetMultimap; 24 import com.google.common.collect.SetMultimap; 25 import java.lang.annotation.Annotation; 26 import java.util.function.Function; 27 import javax.lang.model.element.Element; 28 29 /** 30 * A {@link ProcessingStep} that processes one element at a time and defers any for which {@link 31 * TypeNotPresentException} is thrown. 32 */ 33 // TODO(dpb): Contribute to auto-common. 34 abstract class TypeCheckingProcessingStep<E extends Element> implements ProcessingStep { 35 private final Function<Element, E> downcaster; 36 TypeCheckingProcessingStep(Function<Element, E> downcaster)37 TypeCheckingProcessingStep(Function<Element, E> downcaster) { 38 this.downcaster = checkNotNull(downcaster); 39 } 40 41 @Override process( SetMultimap<Class<? extends Annotation>, Element> elementsByAnnotation)42 public ImmutableSet<Element> process( 43 SetMultimap<Class<? extends Annotation>, Element> elementsByAnnotation) { 44 ImmutableSet.Builder<Element> deferredElements = ImmutableSet.builder(); 45 ImmutableSetMultimap.copyOf(elementsByAnnotation) 46 .inverse() 47 .asMap() 48 .forEach( 49 (element, annotations) -> { 50 try { 51 process(downcaster.apply(element), ImmutableSet.copyOf(annotations)); 52 } catch (TypeNotPresentException e) { 53 deferredElements.add(element); 54 } 55 }); 56 return deferredElements.build(); 57 } 58 59 /** 60 * Processes one element. If this method throws {@link TypeNotPresentException}, the element will 61 * be deferred until the next round of processing. 62 * 63 * @param annotations the subset of {@link ProcessingStep#annotations()} that annotate {@code 64 * element} 65 */ process(E element, ImmutableSet<Class<? extends Annotation>> annotations)66 protected abstract void process(E element, ImmutableSet<Class<? extends Annotation>> annotations); 67 } 68