From 916a871fbcc2b21c3f456613c28d498cb3f5750a Mon Sep 17 00:00:00 2001
From: Stephane Nicoll <snicoll@vmware.com>
Date: Fri, 29 Jul 2022 15:38:09 +0200
Subject: [PATCH] Add dedicated hint support for composable annotations

This commit adds a dedicated method for annotations that are used as
meta-annotation when the composed annotation does not require to be
visible at runtime.

Closes gh-28887
---
 .../aot/hint/support/RuntimeHintsUtils.java   | 20 ++++++++++++++++++-
 .../hint/support/RuntimeHintsUtilsTests.java  |  9 +++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/spring-core/src/main/java/org/springframework/aot/hint/support/RuntimeHintsUtils.java b/spring-core/src/main/java/org/springframework/aot/hint/support/RuntimeHintsUtils.java
index a859807883..6976b39f04 100644
--- a/spring-core/src/main/java/org/springframework/aot/hint/support/RuntimeHintsUtils.java
+++ b/spring-core/src/main/java/org/springframework/aot/hint/support/RuntimeHintsUtils.java
@@ -57,6 +57,24 @@ public abstract class RuntimeHintsUtils {
 	 * @see SynthesizedAnnotation
 	 */
 	public static void registerAnnotation(RuntimeHints hints, Class<?> annotationType) {
+		registerAnnotation(hints, annotationType, false);
+	}
+
+	/**
+	 * Register the necessary hints so that the specified <em>composable</em>
+	 * annotation is visible at runtime. Use this method rather than the regular
+	 * {@link #registerAnnotation(RuntimeHints, Class)} when the specified
+	 * annotation is meta-annotated, but the meta-annotated annotations do not
+	 * need to be visible.
+	 * @param hints the {@link RuntimeHints} instance to use
+	 * @param annotationType the composable annotation type
+	 * @see #registerAnnotation(RuntimeHints, Class)
+	 */
+	public static void registerComposableAnnotation(RuntimeHints hints, Class<?> annotationType) {
+		registerAnnotation(hints, annotationType, true);
+	}
+
+	private static void registerAnnotation(RuntimeHints hints, Class<?> annotationType, boolean withProxy) {
 		hints.reflection().registerType(annotationType, ANNOTATION_HINT);
 		Set<Class<?>> allAnnotations = new LinkedHashSet<>();
 		collectAliasedAnnotations(new HashSet<>(), allAnnotations, annotationType);
@@ -64,7 +82,7 @@ public abstract class RuntimeHintsUtils {
 			hints.reflection().registerType(annotation, ANNOTATION_HINT);
 			hints.proxies().registerJdkProxy(annotation, SynthesizedAnnotation.class);
 		});
-		if (!allAnnotations.isEmpty()) {
+		if (!allAnnotations.isEmpty() || withProxy) {
 			hints.proxies().registerJdkProxy(annotationType, SynthesizedAnnotation.class);
 		}
 	}
diff --git a/spring-core/src/test/java/org/springframework/aot/hint/support/RuntimeHintsUtilsTests.java b/spring-core/src/test/java/org/springframework/aot/hint/support/RuntimeHintsUtilsTests.java
index 385a2c951b..8d57da8762 100644
--- a/spring-core/src/test/java/org/springframework/aot/hint/support/RuntimeHintsUtilsTests.java
+++ b/spring-core/src/test/java/org/springframework/aot/hint/support/RuntimeHintsUtilsTests.java
@@ -50,6 +50,15 @@ class RuntimeHintsUtilsTests {
 		assertThat(this.hints.proxies().jdkProxies()).isEmpty();
 	}
 
+	@Test
+	void registerComposableAnnotationType() {
+		RuntimeHintsUtils.registerComposableAnnotation(this.hints, SampleInvoker.class);
+		assertThat(this.hints.reflection().typeHints()).singleElement()
+				.satisfies(annotationHint(SampleInvoker.class));
+		assertThat(this.hints.proxies().jdkProxies()).singleElement()
+				.satisfies(annotationProxy(SampleInvoker.class));
+	}
+
 	@Test
 	void registerAnnotationTypeWithLocalUseOfAliasForRegistersProxy() {
 		RuntimeHintsUtils.registerAnnotation(this.hints, LocalMapping.class);