Improve stereotypes support

This commit adds a better API for registering custom stereotypes, similar
to existing APIs: `StereotypeRegistrar` and `StereotypeRegistrarBuildItem`.
The existing `AdditionalStereotypeBuildItem` is very confusing to use, so
it is deprecated and all its usages are replaced with the new API.

Also, this commit allows defining stereotypes for synthetic beans. Scope,
name, alternative status and priority are all applied to the synthetic bean,
but interceptor bindings are not. We don't apply interceptors to synthetic
beans in general, this case is not an exception.

docs/src/main/asciidoc/cdi-integration.adoc

@@ -478,6 +478,28 @@ QualifierRegistrarBuildItem addQualifiers() {
 }
 ----
 
+== Use Case - Additional Stereotypes
+
+It is sometimes useful to register an existing annotation that is not annotated with `@javax.enterprise.inject.Stereotype` as a CDI stereotype.
+This is similar to what CDI achieves through `BeforeBeanDiscovery#addStereotype()`.
+We are going to use `StereotypeRegistrarBuildItem` to get it done.
+
+.`StereotypeRegistrarBuildItem` Example
+[source,java]
+----
+@BuildStep
+StereotypeRegistrarBuildItem addStereotypes() {
+    return new StereotypeRegistrarBuildItem(new StereotypeRegistrar() {
+        @Override
+        public Set<DotName> getAdditionalStereotypes() {
+            return Collections.singleton(DotName.createSimple(NotAStereotype.class.getName()));
+        }
+    });
+}
+----
+
+If the newly registered stereotype annotation doesn't have the appropriate meta-annotations, such as scope or interceptor bindings, use an <<annotations_transformer_build_item,annotation transformation>> to add them.
+
 [[injection_point_transformation]]
 == Use Case - Injection Point Transformation
 

extensions/arc/deployment/src/main/java/io/quarkus/arc/deployment/AdditionalStereotypeBuildItem.java

@@ -9,8 +9,13 @@
 import io.quarkus.builder.item.MultiBuildItem;
 
 /**
- * A map of additional stereotype classes to their instances that we want to process.
+ * A map of additional annotation types (that have the same meaning as the {@code @Stereotype} meta-annotation)
+ * to their occurences on other annotations (that become custom stereotypes).
+ *
+ * @deprecated use {@link StereotypeRegistrarBuildItem};
+ *             this class will be removed at some time after Quarkus 3.0
  */
+@Deprecated
 public final class AdditionalStereotypeBuildItem extends MultiBuildItem {
 
     private final Map<DotName, Collection<AnnotationInstance>> stereotypes;

extensions/arc/deployment/src/main/java/io/quarkus/arc/deployment/ArcProcessor.java

@@ -71,6 +71,7 @@
 import io.quarkus.arc.processor.ReflectionRegistration;
 import io.quarkus.arc.processor.ResourceOutput;
 import io.quarkus.arc.processor.StereotypeInfo;
+import io.quarkus.arc.processor.StereotypeRegistrar;
 import io.quarkus.arc.processor.Transformation;
 import io.quarkus.arc.processor.Types;
 import io.quarkus.arc.runtime.AdditionalBean;
@@ -154,6 +155,25 @@ AdditionalBeanBuildItem quarkusApplication(CombinedIndexBuildItem combinedIndex)
                 .build();
     }
 
+    @BuildStep
+    StereotypeRegistrarBuildItem convertLegacyAdditionalStereotypes(List<AdditionalStereotypeBuildItem> buildItems) {
+        return new StereotypeRegistrarBuildItem(new StereotypeRegistrar() {
+            @Override
+            public Set<DotName> getAdditionalStereotypes() {
+                Set<DotName> result = new HashSet<>();
+                for (AdditionalStereotypeBuildItem buildItem : buildItems) {
+                    result.addAll(buildItem.getStereotypes()
+                            .values()
+                            .stream()
+                            .flatMap(Collection::stream)
+                            .map(AnnotationInstance::name)
+                            .collect(Collectors.toSet()));
+                }
+                return result;
+            }
+        });
+    }
+
     // PHASE 1 - build BeanProcessor
     @BuildStep
     public ContextRegistrationPhaseBuildItem initialize(
@@ -167,7 +187,7 @@ public ContextRegistrationPhaseBuildItem initialize(
             List<ObserverTransformerBuildItem> observerTransformers,
             List<InterceptorBindingRegistrarBuildItem> interceptorBindingRegistrars,
             List<QualifierRegistrarBuildItem> qualifierRegistrars,
-            List<AdditionalStereotypeBuildItem> additionalStereotypeBuildItems,
+            List<StereotypeRegistrarBuildItem> stereotypeRegistrars,
             List<ApplicationClassPredicateBuildItem> applicationClassPredicates,
             List<AdditionalBeanBuildItem> additionalBeans,
             List<ResourceAnnotationBuildItem> resourceAnnotations,
@@ -251,11 +271,6 @@ public void transform(TransformationContext transformationContext) {
                 .map((s) -> new BeanDefiningAnnotation(s.getName(), s.getDefaultScope())).collect(Collectors.toList());
         beanDefiningAnnotations.add(new BeanDefiningAnnotation(ADDITIONAL_BEAN, null));
         builder.setAdditionalBeanDefiningAnnotations(beanDefiningAnnotations);
-        final Map<DotName, Collection<AnnotationInstance>> additionalStereotypes = new HashMap<>();
-        for (final AdditionalStereotypeBuildItem item : additionalStereotypeBuildItems) {
-            additionalStereotypes.putAll(item.getStereotypes());
-        }
-        builder.setAdditionalStereotypes(additionalStereotypes);
         builder.addResourceAnnotations(
                 resourceAnnotations.stream().map(ResourceAnnotationBuildItem::getName).collect(Collectors.toList()));
         // register all annotation transformers
@@ -278,6 +293,10 @@ public void transform(TransformationContext transformationContext) {
         for (QualifierRegistrarBuildItem registrar : qualifierRegistrars) {
             builder.addQualifierRegistrar(registrar.getQualifierRegistrar());
         }
+        // register additional stereotypes
+        for (StereotypeRegistrarBuildItem registrar : stereotypeRegistrars) {
+            builder.addStereotypeRegistrar(registrar.getStereotypeRegistrar());
+        }
         builder.setRemoveUnusedBeans(arcConfig.shouldEnableBeanRemoval());
         if (arcConfig.shouldOnlyKeepAppBeans()) {
             builder.addRemovalExclusion(new AbstractCompositeApplicationClassesPredicate<BeanInfo>(

extensions/arc/deployment/src/main/java/io/quarkus/arc/deployment/AutoProducerMethodsProcessor.java

@@ -3,7 +3,7 @@
 import static io.quarkus.arc.processor.Annotations.contains;
 import static io.quarkus.arc.processor.Annotations.containsAny;
 
-import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -32,20 +32,20 @@ public class AutoProducerMethodsProcessor {
     @BuildStep
     void annotationTransformer(ArcConfig config, BeanArchiveIndexBuildItem beanArchiveIndex,
             CustomScopeAnnotationsBuildItem scopes,
-            List<AdditionalStereotypeBuildItem> additionalStereotypes,
+            List<StereotypeRegistrarBuildItem> stereotypeRegistrars,
             BuildProducer<AnnotationsTransformerBuildItem> annotationsTransformer) throws Exception {
         if (!config.autoProducerMethods) {
             return;
         }
-        List<DotName> qualifiersAndStereotypes = new ArrayList<>();
+        Set<DotName> qualifiersAndStereotypes = new HashSet<>();
         for (AnnotationInstance qualifier : beanArchiveIndex.getIndex().getAnnotations(DotNames.QUALIFIER)) {
             qualifiersAndStereotypes.add(qualifier.target().asClass().name());
         }
-        for (AnnotationInstance qualifier : beanArchiveIndex.getIndex().getAnnotations(DotNames.STEREOTYPE)) {
-            qualifiersAndStereotypes.add(qualifier.target().asClass().name());
+        for (AnnotationInstance stereotype : beanArchiveIndex.getIndex().getAnnotations(DotNames.STEREOTYPE)) {
+            qualifiersAndStereotypes.add(stereotype.target().asClass().name());
         }
-        for (AdditionalStereotypeBuildItem additionalStereotype : additionalStereotypes) {
-            qualifiersAndStereotypes.addAll(additionalStereotype.getStereotypes().keySet());
+        for (StereotypeRegistrarBuildItem stereotypeRegistrar : stereotypeRegistrars) {
+            qualifiersAndStereotypes.addAll(stereotypeRegistrar.getStereotypeRegistrar().getAdditionalStereotypes());
         }
         LOGGER.debugf("Add missing @Produces to methods annotated with %s", qualifiersAndStereotypes);
         annotationsTransformer.produce(new AnnotationsTransformerBuildItem(new AnnotationsTransformer() {

extensions/arc/deployment/src/main/java/io/quarkus/arc/deployment/StereotypeRegistrarBuildItem.java

@@ -0,0 +1,21 @@
+package io.quarkus.arc.deployment;
+
+import io.quarkus.arc.processor.StereotypeRegistrar;
+import io.quarkus.builder.item.MultiBuildItem;
+
+/**
+ * Makes it possible to register annotations that should be considered stereotypes but are not annotated with
+ * {@code javax.enterprise.inject.Stereotype}.
+ */
+public final class StereotypeRegistrarBuildItem extends MultiBuildItem {
+
+    private final StereotypeRegistrar registrar;
+
+    public StereotypeRegistrarBuildItem(StereotypeRegistrar registrar) {
+        this.registrar = registrar;
+    }
+
+    public StereotypeRegistrar getStereotypeRegistrar() {
+        return registrar;
+    }
+}

extensions/smallrye-health/deployment/src/main/java/io/quarkus/smallrye/health/deployment/SmallRyeHealthProcessor.java

@@ -363,7 +363,10 @@ AnnotationsTransformerBuildItem annotationTransformer(BeanArchiveIndexBuildItem
                 stereotypeAnnotations.add(annotationClass.name());
             }
         }
-        List<DotName> healthAnnotations = new ArrayList<>(5);
+        // TODO additional stereotypes? see AutoProducerMethodsProcessor.annotationTransformer
+        //  (note that CustomScopeAnnotationsBuildItem ignores ArC annotation transformations)
+
+        List<DotName> healthAnnotations = new ArrayList<>(6);
         healthAnnotations.add(LIVENESS);
         healthAnnotations.add(READINESS);
         healthAnnotations.add(STARTUP);

extensions/spring-di/deployment/src/main/java/io/quarkus/spring/di/deployment/SpringDIProcessor.java

@@ -27,21 +27,22 @@
 import org.jboss.jandex.MethodParameterInfo;
 import org.jboss.jandex.Type;
 
-import io.quarkus.arc.deployment.AdditionalStereotypeBuildItem;
 import io.quarkus.arc.deployment.AnnotationsTransformerBuildItem;
 import io.quarkus.arc.deployment.BeanArchiveIndexBuildItem;
+import io.quarkus.arc.deployment.StereotypeRegistrarBuildItem;
 import io.quarkus.arc.processor.BuiltinScope;
 import io.quarkus.arc.processor.DotNames;
+import io.quarkus.arc.processor.StereotypeRegistrar;
 import io.quarkus.arc.processor.Transformation;
 import io.quarkus.deployment.Feature;
 import io.quarkus.deployment.annotations.BuildProducer;
 import io.quarkus.deployment.annotations.BuildStep;
 import io.quarkus.deployment.builditem.FeatureBuildItem;
 
-/*
- * A simple processor that maps annotations Spring DI annotation to CDI annotation
+/**
+ * A simple processor that maps Spring DI annotations to CDI annotations.
  * Arc's handling of annotation mapping (by creating an extra abstraction layer on top of the Jandex index)
- * suits this sort of handling perfectly
+ * suits this sort of handling perfectly.
  */
 public class SpringDIProcessor {
 
@@ -50,11 +51,10 @@ public class SpringDIProcessor {
     static final DotName SPRING_COMPONENT = DotName.createSimple("org.springframework.stereotype.Component");
     static final DotName SPRING_SERVICE = DotName.createSimple("org.springframework.stereotype.Service");
     static final DotName SPRING_REPOSITORY = DotName.createSimple("org.springframework.stereotype.Repository");
-    private static final Set<DotName> SPRING_STEREOTYPE_ANNOTATIONS = Arrays.stream(new DotName[] {
+    private static final Set<DotName> SPRING_STEREOTYPE_ANNOTATIONS = Set.of(
             SPRING_COMPONENT,
             SPRING_SERVICE,
-            SPRING_REPOSITORY,
-    }).collect(Collectors.toSet());
+            SPRING_REPOSITORY);
 
     private static final DotName CONFIGURATION_ANNOTATION = DotName
             .createSimple("org.springframework.context.annotation.Configuration");
@@ -120,18 +120,24 @@ SpringBeanNameToDotNameBuildItem createBeanNamesMap(BeanArchiveIndexBuildItem be
     @BuildStep
     AnnotationsTransformerBuildItem beanTransformer(
             final BeanArchiveIndexBuildItem beanArchiveIndexBuildItem,
-            final BuildProducer<AdditionalStereotypeBuildItem> additionalStereotypeBuildItemBuildProducer) {
+            final BuildProducer<StereotypeRegistrarBuildItem> stereotypeRegistrarProducer) {
         final IndexView index = beanArchiveIndexBuildItem.getIndex();
         final Map<DotName, Set<DotName>> stereotypeScopes = getStereotypeScopes(index);
-        final Map<DotName, Collection<AnnotationInstance>> instances = new HashMap<>();
+        final Set<DotName> stereotypeAnnotations = new HashSet<>();
         for (final DotName name : stereotypeScopes.keySet()) {
-            instances.put(name, index.getAnnotations(name)
+            stereotypeAnnotations.addAll(index.getAnnotations(name)
                     .stream()
                     .filter(it -> it.target().kind() == AnnotationTarget.Kind.CLASS
                             && it.target().asClass().isAnnotation())
+                    .map(AnnotationInstance::name)
                     .collect(Collectors.toSet()));
         }
-        additionalStereotypeBuildItemBuildProducer.produce(new AdditionalStereotypeBuildItem(instances));
+        stereotypeRegistrarProducer.produce(new StereotypeRegistrarBuildItem(new StereotypeRegistrar() {
+            @Override
+            public Set<DotName> getAdditionalStereotypes() {
+                return stereotypeAnnotations;
+            }
+        }));
         return new AnnotationsTransformerBuildItem(context -> {
             final Collection<AnnotationInstance> annotations = context.getAnnotations();
             if (annotations.isEmpty()) {

independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanConfigurator.java

@@ -43,6 +43,31 @@ public void done() {
             if (implClass == null) {
                 throw new IllegalStateException("Unable to find the bean class in the index: " + implClazz);
             }
+
+            ScopeInfo scope = this.scope;
+            if (scope == null) {
+                scope = Beans.initStereotypeScope(stereotypes, implClass, beanDeployment);
+            }
+            if (scope == null) {
+                scope = BuiltinScope.DEPENDENT.getInfo();
+            }
+
+            String name = this.name;
+            if (name == null) {
+                name = Beans.initStereotypeName(stereotypes, implClass);
+            }
+
+            Boolean alternative = this.alternative;
+            if (alternative == null) {
+                alternative = Beans.initStereotypeAlternative(stereotypes);
+            }
+
+            Integer priority = this.priority;
+            if (priority == null) {
+                // TODO use `Beans.initAlternativePriority` instead? IMHO no for synthetic beans
+                priority = Beans.initStereotypeAlternativePriority(stereotypes);
+            }
+
             beanConsumer.accept(new BeanInfo.Builder()
                     .implClazz(implClass)
                     .providerType(providerType)
@@ -52,6 +77,7 @@ public void done() {
                     .qualifiers(qualifiers)
                     .alternative(alternative)
                     .priority(priority)
+                    .stereotypes(stereotypes)
                     .name(name)
                     .creator(creatorConsumer)
                     .destroyer(destroyerConsumer)

independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanConfiguratorBase.java

@@ -9,8 +9,10 @@
 import io.quarkus.gizmo.ResultHandle;
 import java.lang.annotation.Annotation;
 import java.lang.annotation.Inherited;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Consumer;
@@ -32,7 +34,8 @@ public abstract class BeanConfiguratorBase<THIS extends BeanConfiguratorBase<THI
     protected final Set<Type> types;
     protected final Set<AnnotationInstance> qualifiers;
     protected ScopeInfo scope;
-    protected boolean alternative;
+    protected Boolean alternative;
+    protected final List<StereotypeInfo> stereotypes;
     protected String name;
     protected Consumer<MethodCreator> creatorConsumer;
     protected Consumer<MethodCreator> destroyerConsumer;
@@ -47,7 +50,7 @@ protected BeanConfiguratorBase(DotName implClazz) {
         this.implClazz = implClazz;
         this.types = new HashSet<>();
         this.qualifiers = new HashSet<>();
-        this.scope = BuiltinScope.DEPENDENT.getInfo();
+        this.stereotypes = new ArrayList<>();
         this.removable = true;
     }
 
@@ -68,6 +71,8 @@ public THIS read(BeanConfiguratorBase<?, ?> base) {
         scope(base.scope);
         alternative = base.alternative;
         priority = base.priority;
+        stereotypes.clear();
+        stereotypes.addAll(base.stereotypes);
         name(base.name);
         creator(base.creatorConsumer);
         destroyer(base.destroyerConsumer);
@@ -197,6 +202,16 @@ public THIS priority(int value) {
         return self();
     }
 
+    public THIS addStereotype(StereotypeInfo stereotype) {
+        this.stereotypes.add(stereotype);
+        return self();
+    }
+
+    public THIS stereotypes(StereotypeInfo... stereotypes) {
+        Collections.addAll(this.stereotypes, stereotypes);
+        return self();
+    }
+
     /**
      * The provider type is the "real" type of the bean instance created via
      * {@link InjectableReferenceProvider#get(CreationalContext)}.