java/dagger/internal/codegen/ComponentHjarProcessingStep.java - platform/external/dagger2 - Gitiles

 /*
  * Copyright (C) 2017 The Dagger Authors.
  *
  * 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 dagger.internal.codegen;

 import static com.google.auto.common.MoreElements.isAnnotationPresent;
 import static com.google.common.base.CaseFormat.LOWER_CAMEL;
 import static com.google.common.base.CaseFormat.UPPER_CAMEL;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.squareup.javapoet.MethodSpec.constructorBuilder;
 import static dagger.internal.codegen.ComponentGenerator.componentName;
 import static dagger.internal.codegen.ComponentProcessingStep.getElementsFromAnnotations;
 import static dagger.internal.codegen.TypeSpecs.addSupertype;
 import static javax.lang.model.element.Modifier.ABSTRACT;
 import static javax.lang.model.element.Modifier.FINAL;
 import static javax.lang.model.element.Modifier.PRIVATE;
 import static javax.lang.model.element.Modifier.PUBLIC;
 import static javax.lang.model.element.Modifier.STATIC;
 import static javax.lang.model.util.ElementFilter.methodsIn;

 import com.google.auto.common.BasicAnnotationProcessor.ProcessingStep;
 import com.google.auto.common.MoreElements;
 import com.google.auto.common.MoreTypes;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.SetMultimap;
 import com.google.common.collect.Sets;
 import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.MethodSpec;
 import com.squareup.javapoet.TypeName;
 import com.squareup.javapoet.TypeSpec;
 import dagger.BindsInstance;
 import dagger.Component;
 import dagger.internal.codegen.ComponentDescriptor.Factory;
 import dagger.internal.codegen.ComponentValidator.ComponentValidationReport;
 import dagger.producers.ProductionComponent;
 import java.lang.annotation.Annotation;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Stream;
 import javax.annotation.processing.Filer;
 import javax.annotation.processing.Messager;
 import javax.inject.Inject;
 import javax.lang.model.SourceVersion;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.util.Elements;
 import javax.lang.model.util.Types;

 /**
  * A processing step that emits the API of a generated component, without any actual implementation.
  *
  * <p>When compiling a header jar (hjar), Bazel needs to run annotation processors that generate
  * API, like Dagger, to see what code they might output. Full {@link BindingGraph} analysis is
  * costly and unnecessary from the perspective of the header compiler; it's sole goal is to pass
  * along a slimmed down version of what will be the jar for a particular compilation, whether or not
  * that compilation succeeds. If it does not, the compilation pipeline will fail, even if header
  * compilation succeeded.
  *
  * <p>The components emitted by this processing step include all of the API elements exposed by the
  * normal {@link AbstractComponentWriter}. Method bodies are omitted as Turbine ignores them
  * entirely.
  */
 final class ComponentHjarProcessingStep implements ProcessingStep {
   private final Elements elements;
   private final SourceVersion sourceVersion;
   private final Types types;
   private final Filer filer;
   private final Messager messager;
   private final ComponentValidator componentValidator;
   private final ComponentDescriptor.Factory componentDescriptorFactory;

   @Inject
   ComponentHjarProcessingStep(
       Elements elements,
       SourceVersion sourceVersion,
       Types types,
       Filer filer,
       Messager messager,
       ComponentValidator componentValidator,
       Factory componentDescriptorFactory) {
     this.elements = elements;
     this.sourceVersion = sourceVersion;
     this.types = types;
     this.filer = filer;
     this.messager = messager;
     this.componentValidator = componentValidator;
     this.componentDescriptorFactory = componentDescriptorFactory;
   }

   @Override
   public Set<Class<? extends Annotation>> annotations() {
     return ImmutableSet.of(Component.class, ProductionComponent.class);
   }

   @Override
   public ImmutableSet<Element> process(
       SetMultimap<Class<? extends Annotation>, Element> elementsByAnnotation) {
     ImmutableSet.Builder<Element> rejectedElements = ImmutableSet.builder();

     ImmutableSet<Element> componentElements =
         getElementsFromAnnotations(
             elementsByAnnotation, Component.class, ProductionComponent.class);

     for (Element element : componentElements) {
       TypeElement componentTypeElement = MoreElements.asType(element);
       try {
         // TODO(ronshapiro): component validation might not be necessary. We should measure it and
         // figure out if it's worth seeing if removing it will still work. We could potentially
         // add a new catch clause for any exception that's not TypeNotPresentException and ignore
         // the component entirely in that case.
         ComponentValidationReport validationReport =
             componentValidator.validate(componentTypeElement, ImmutableSet.of(), ImmutableSet.of());
         validationReport.report().printMessagesTo(messager);
         if (validationReport.report().isClean()) {
           new EmptyComponentGenerator(filer, elements, sourceVersion)
               .generate(componentDescriptorFactory.forComponent(componentTypeElement), messager);
         }
       } catch (TypeNotPresentException e) {
         rejectedElements.add(componentTypeElement);
       }
     }
     return rejectedElements.build();
   }

   private final class EmptyComponentGenerator extends SourceFileGenerator<ComponentDescriptor> {
     EmptyComponentGenerator(Filer filer, Elements elements, SourceVersion sourceVersion) {
       super(filer, elements, sourceVersion);
     }

     @Override
     ClassName nameGeneratedType(ComponentDescriptor input) {
       return componentName(input.componentDefinitionType());
     }

     @Override
     Optional<? extends Element> getElementForErrorReporting(ComponentDescriptor input) {
       return Optional.of(input.componentDefinitionType());
     }

     @Override
     Optional<TypeSpec.Builder> write(
         ClassName generatedTypeName, ComponentDescriptor componentDescriptor) {
       TypeSpec.Builder generatedComponent =
           TypeSpec.classBuilder(generatedTypeName)
               .addModifiers(PUBLIC, FINAL)
               .addMethod(privateConstructor());
       TypeElement componentElement = componentDescriptor.componentDefinitionType();
       addSupertype(generatedComponent, componentElement);

       TypeName builderMethodReturnType;
       if (componentDescriptor.builderSpec().isPresent()) {
         builderMethodReturnType =
             ClassName.get(componentDescriptor.builderSpec().get().builderDefinitionType());
       } else {
         TypeSpec.Builder builder =
             TypeSpec.classBuilder("Builder")
                 .addModifiers(PUBLIC, STATIC, FINAL)
                 .addMethod(privateConstructor());
         ClassName builderClassName = generatedTypeName.nestedClass("Builder");
         builderMethodReturnType = builderClassName;
         componentRequirements(componentDescriptor)
             .map(requirement -> builderInstanceMethod(requirement.typeElement(), builderClassName))
             .forEach(builder::addMethod);
         builder.addMethod(builderBuildMethod(componentDescriptor));
         generatedComponent.addType(builder.build());
       }

       generatedComponent.addMethod(staticBuilderMethod(builderMethodReturnType));

       if (componentRequirements(componentDescriptor)
               .noneMatch(requirement -> requirement.requiresAPassedInstance(elements, types))
           && !hasBindsInstanceMethods(componentDescriptor)) {
         generatedComponent.addMethod(createMethod(componentDescriptor));
       }

       DeclaredType componentType = MoreTypes.asDeclared(componentElement.asType());
       // TODO(ronshapiro): unify with AbstractComponentWriter
       Set<MethodSignature> methodSignatures =
           Sets.newHashSetWithExpectedSize(componentDescriptor.componentMethods().size());
       componentDescriptor
           .componentMethods()
           .stream()
           .filter(
               method -> {
                 return methodSignatures.add(
                     MethodSignature.forComponentMethod(method, componentType, types));
               })
           .forEach(
               method ->
                   generatedComponent.addMethod(
                       emptyComponentMethod(componentElement, method.methodElement())));

       return Optional.of(generatedComponent);
     }
   }

   private MethodSpec emptyComponentMethod(TypeElement typeElement, ExecutableElement baseMethod) {
     return MethodSpec.overriding(baseMethod, MoreTypes.asDeclared(typeElement.asType()), types)
         .build();
   }

   private MethodSpec privateConstructor() {
     return constructorBuilder().addModifiers(PRIVATE).build();
   }

   /**
    * Returns the {@link ComponentRequirement}s for a component that does not have a {@link
    * ComponentDescriptor#builderSpec()}.
    */
   private Stream<ComponentRequirement> componentRequirements(ComponentDescriptor component) {
     checkArgument(component.kind().isTopLevel());
     return Stream.concat(
         component.dependencies().stream(),
         component
             .transitiveModules()
             .stream()
             .filter(module -> !module.moduleElement().getModifiers().contains(ABSTRACT))
             .map(module -> ComponentRequirement.forModule(module.moduleElement().asType())));
   }

   private boolean hasBindsInstanceMethods(ComponentDescriptor componentDescriptor) {
     return componentDescriptor.builderSpec().isPresent()
         && methodsIn(
                 elements.getAllMembers(
                     componentDescriptor.builderSpec().get().builderDefinitionType()))
             .stream()
             .anyMatch(method -> isAnnotationPresent(method, BindsInstance.class));
   }

   private MethodSpec builderInstanceMethod(
       TypeElement componentRequirement, ClassName builderClass) {
     String simpleName =
         UPPER_CAMEL.to(LOWER_CAMEL, componentRequirement.getSimpleName().toString());
     return MethodSpec.methodBuilder(simpleName)
         .addModifiers(PUBLIC)
         .addParameter(ClassName.get(componentRequirement), simpleName)
         .returns(builderClass)
         .build();
   }

   private MethodSpec builderBuildMethod(ComponentDescriptor component) {
     return MethodSpec.methodBuilder("build")
         .addModifiers(PUBLIC)
         .returns(ClassName.get(component.componentDefinitionType()))
         .build();
   }

   private MethodSpec staticBuilderMethod(TypeName builderMethodReturnType) {
     return MethodSpec.methodBuilder("builder")
         .addModifiers(PUBLIC, STATIC)
         .returns(builderMethodReturnType)
         .build();
   }

   private MethodSpec createMethod(ComponentDescriptor componentDescriptor) {
     return MethodSpec.methodBuilder("create")
         .addModifiers(PUBLIC, STATIC)
         .returns(ClassName.get(componentDescriptor.componentDefinitionType()))
         .build();
   }
 }
	/*
	* Copyright (C) 2017 The Dagger Authors.
	*
	* 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 dagger.internal.codegen;

	import static com.google.auto.common.MoreElements.isAnnotationPresent;
	import static com.google.common.base.CaseFormat.LOWER_CAMEL;
	import static com.google.common.base.CaseFormat.UPPER_CAMEL;
	import static com.google.common.base.Preconditions.checkArgument;
	import static com.squareup.javapoet.MethodSpec.constructorBuilder;
	import static dagger.internal.codegen.ComponentGenerator.componentName;
	import static dagger.internal.codegen.ComponentProcessingStep.getElementsFromAnnotations;
	import static dagger.internal.codegen.TypeSpecs.addSupertype;
	import static javax.lang.model.element.Modifier.ABSTRACT;
	import static javax.lang.model.element.Modifier.FINAL;
	import static javax.lang.model.element.Modifier.PRIVATE;
	import static javax.lang.model.element.Modifier.PUBLIC;
	import static javax.lang.model.element.Modifier.STATIC;
	import static javax.lang.model.util.ElementFilter.methodsIn;

	import com.google.auto.common.BasicAnnotationProcessor.ProcessingStep;
	import com.google.auto.common.MoreElements;
	import com.google.auto.common.MoreTypes;
	import com.google.common.collect.ImmutableSet;
	import com.google.common.collect.SetMultimap;
	import com.google.common.collect.Sets;
	import com.squareup.javapoet.ClassName;
	import com.squareup.javapoet.MethodSpec;
	import com.squareup.javapoet.TypeName;
	import com.squareup.javapoet.TypeSpec;
	import dagger.BindsInstance;
	import dagger.Component;
	import dagger.internal.codegen.ComponentDescriptor.Factory;
	import dagger.internal.codegen.ComponentValidator.ComponentValidationReport;
	import dagger.producers.ProductionComponent;
	import java.lang.annotation.Annotation;
	import java.util.Optional;
	import java.util.Set;
	import java.util.stream.Stream;
	import javax.annotation.processing.Filer;
	import javax.annotation.processing.Messager;
	import javax.inject.Inject;
	import javax.lang.model.SourceVersion;
	import javax.lang.model.element.Element;
	import javax.lang.model.element.ExecutableElement;
	import javax.lang.model.element.TypeElement;
	import javax.lang.model.type.DeclaredType;
	import javax.lang.model.util.Elements;
	import javax.lang.model.util.Types;

	/**
	* A processing step that emits the API of a generated component, without any actual implementation.
	*
	* <p>When compiling a header jar (hjar), Bazel needs to run annotation processors that generate
	* API, like Dagger, to see what code they might output. Full {@link BindingGraph} analysis is
	* costly and unnecessary from the perspective of the header compiler; it's sole goal is to pass
	* along a slimmed down version of what will be the jar for a particular compilation, whether or not
	* that compilation succeeds. If it does not, the compilation pipeline will fail, even if header
	* compilation succeeded.
	*
	* <p>The components emitted by this processing step include all of the API elements exposed by the
	* normal {@link AbstractComponentWriter}. Method bodies are omitted as Turbine ignores them
	* entirely.
	*/
	final class ComponentHjarProcessingStep implements ProcessingStep {
	private final Elements elements;
	private final SourceVersion sourceVersion;
	private final Types types;
	private final Filer filer;
	private final Messager messager;
	private final ComponentValidator componentValidator;
	private final ComponentDescriptor.Factory componentDescriptorFactory;

	@Inject
	ComponentHjarProcessingStep(
	Elements elements,
	SourceVersion sourceVersion,
	Types types,
	Filer filer,
	Messager messager,
	ComponentValidator componentValidator,
	Factory componentDescriptorFactory) {
	this.elements = elements;
	this.sourceVersion = sourceVersion;
	this.types = types;
	this.filer = filer;
	this.messager = messager;
	this.componentValidator = componentValidator;
	this.componentDescriptorFactory = componentDescriptorFactory;
	}

	@Override
	public Set<Class<? extends Annotation>> annotations() {
	return ImmutableSet.of(Component.class, ProductionComponent.class);
	}

	@Override
	public ImmutableSet<Element> process(
	SetMultimap<Class<? extends Annotation>, Element> elementsByAnnotation) {
	ImmutableSet.Builder<Element> rejectedElements = ImmutableSet.builder();

	ImmutableSet<Element> componentElements =
	getElementsFromAnnotations(
	elementsByAnnotation, Component.class, ProductionComponent.class);

	for (Element element : componentElements) {
	TypeElement componentTypeElement = MoreElements.asType(element);
	try {
	// TODO(ronshapiro): component validation might not be necessary. We should measure it and
	// figure out if it's worth seeing if removing it will still work. We could potentially
	// add a new catch clause for any exception that's not TypeNotPresentException and ignore
	// the component entirely in that case.
	ComponentValidationReport validationReport =
	componentValidator.validate(componentTypeElement, ImmutableSet.of(), ImmutableSet.of());
	validationReport.report().printMessagesTo(messager);
	if (validationReport.report().isClean()) {
	new EmptyComponentGenerator(filer, elements, sourceVersion)
	.generate(componentDescriptorFactory.forComponent(componentTypeElement), messager);
	}
	} catch (TypeNotPresentException e) {
	rejectedElements.add(componentTypeElement);
	}
	}
	return rejectedElements.build();
	}

	private final class EmptyComponentGenerator extends SourceFileGenerator<ComponentDescriptor> {
	EmptyComponentGenerator(Filer filer, Elements elements, SourceVersion sourceVersion) {
	super(filer, elements, sourceVersion);
	}

	@Override
	ClassName nameGeneratedType(ComponentDescriptor input) {
	return componentName(input.componentDefinitionType());
	}

	@Override
	Optional<? extends Element> getElementForErrorReporting(ComponentDescriptor input) {
	return Optional.of(input.componentDefinitionType());
	}

	@Override
	Optional<TypeSpec.Builder> write(
	ClassName generatedTypeName, ComponentDescriptor componentDescriptor) {
	TypeSpec.Builder generatedComponent =
	TypeSpec.classBuilder(generatedTypeName)
	.addModifiers(PUBLIC, FINAL)
	.addMethod(privateConstructor());
	TypeElement componentElement = componentDescriptor.componentDefinitionType();
	addSupertype(generatedComponent, componentElement);

	TypeName builderMethodReturnType;
	if (componentDescriptor.builderSpec().isPresent()) {
	builderMethodReturnType =
	ClassName.get(componentDescriptor.builderSpec().get().builderDefinitionType());
	} else {
	TypeSpec.Builder builder =
	TypeSpec.classBuilder("Builder")
	.addModifiers(PUBLIC, STATIC, FINAL)
	.addMethod(privateConstructor());
	ClassName builderClassName = generatedTypeName.nestedClass("Builder");
	builderMethodReturnType = builderClassName;
	componentRequirements(componentDescriptor)
	.map(requirement -> builderInstanceMethod(requirement.typeElement(), builderClassName))
	.forEach(builder::addMethod);
	builder.addMethod(builderBuildMethod(componentDescriptor));
	generatedComponent.addType(builder.build());
	}

	generatedComponent.addMethod(staticBuilderMethod(builderMethodReturnType));

	if (componentRequirements(componentDescriptor)
	.noneMatch(requirement -> requirement.requiresAPassedInstance(elements, types))
	&& !hasBindsInstanceMethods(componentDescriptor)) {
	generatedComponent.addMethod(createMethod(componentDescriptor));
	}

	DeclaredType componentType = MoreTypes.asDeclared(componentElement.asType());
	// TODO(ronshapiro): unify with AbstractComponentWriter
	Set<MethodSignature> methodSignatures =
	Sets.newHashSetWithExpectedSize(componentDescriptor.componentMethods().size());
	componentDescriptor
	.componentMethods()
	.stream()
	.filter(
	method -> {
	return methodSignatures.add(
	MethodSignature.forComponentMethod(method, componentType, types));
	})
	.forEach(
	method ->
	generatedComponent.addMethod(
	emptyComponentMethod(componentElement, method.methodElement())));

	return Optional.of(generatedComponent);
	}
	}

	private MethodSpec emptyComponentMethod(TypeElement typeElement, ExecutableElement baseMethod) {
	return MethodSpec.overriding(baseMethod, MoreTypes.asDeclared(typeElement.asType()), types)
	.build();
	}

	private MethodSpec privateConstructor() {
	return constructorBuilder().addModifiers(PRIVATE).build();
	}

	/**
	* Returns the {@link ComponentRequirement}s for a component that does not have a {@link
	* ComponentDescriptor#builderSpec()}.
	*/
	private Stream<ComponentRequirement> componentRequirements(ComponentDescriptor component) {
	checkArgument(component.kind().isTopLevel());
	return Stream.concat(
	component.dependencies().stream(),
	component
	.transitiveModules()
	.stream()
	.filter(module -> !module.moduleElement().getModifiers().contains(ABSTRACT))
	.map(module -> ComponentRequirement.forModule(module.moduleElement().asType())));
	}

	private boolean hasBindsInstanceMethods(ComponentDescriptor componentDescriptor) {
	return componentDescriptor.builderSpec().isPresent()
	&& methodsIn(
	elements.getAllMembers(
	componentDescriptor.builderSpec().get().builderDefinitionType()))
	.stream()
	.anyMatch(method -> isAnnotationPresent(method, BindsInstance.class));
	}

	private MethodSpec builderInstanceMethod(
	TypeElement componentRequirement, ClassName builderClass) {
	String simpleName =
	UPPER_CAMEL.to(LOWER_CAMEL, componentRequirement.getSimpleName().toString());
	return MethodSpec.methodBuilder(simpleName)
	.addModifiers(PUBLIC)
	.addParameter(ClassName.get(componentRequirement), simpleName)
	.returns(builderClass)
	.build();
	}

	private MethodSpec builderBuildMethod(ComponentDescriptor component) {
	return MethodSpec.methodBuilder("build")
	.addModifiers(PUBLIC)
	.returns(ClassName.get(component.componentDefinitionType()))
	.build();
	}

	private MethodSpec staticBuilderMethod(TypeName builderMethodReturnType) {
	return MethodSpec.methodBuilder("builder")
	.addModifiers(PUBLIC, STATIC)
	.returns(builderMethodReturnType)
	.build();
	}

	private MethodSpec createMethod(ComponentDescriptor componentDescriptor) {
	return MethodSpec.methodBuilder("create")
	.addModifiers(PUBLIC, STATIC)
	.returns(ClassName.get(componentDescriptor.componentDefinitionType()))
	.build();
	}
	}