Fix introspection of annotations that use local aliased attributes

Closes gh-28528

Author: snicoll

spring-core/src/main/java/org/springframework/aot/hint/support/RuntimeHintsUtils.java

@@ -18,6 +18,7 @@
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
+import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.function.Consumer;
@@ -55,24 +56,31 @@ public abstract class RuntimeHintsUtils {
 	 * @see SynthesizedAnnotation
 	 */
 	public static void registerAnnotation(RuntimeHints hints, Class<?> annotationType) {
+		hints.reflection().registerType(annotationType, ANNOTATION_HINT);
 		Set<Class<?>> allAnnotations = new LinkedHashSet<>();
-		allAnnotations.add(annotationType);
-		collectAliasedAnnotations(allAnnotations, annotationType);
+		collectAliasedAnnotations(new HashSet<>(), allAnnotations, annotationType);
 		allAnnotations.forEach(annotation -> hints.reflection().registerType(annotation, ANNOTATION_HINT));
-		if (allAnnotations.size() > 1) {
+		if (allAnnotations.size() > 0) {
 			hints.proxies().registerJdkProxy(annotationType, SynthesizedAnnotation.class);
 		}
 	}
 
-	private static void collectAliasedAnnotations(Set<Class<?>> types, Class<?> annotationType) {
+	private static void collectAliasedAnnotations(Set<Class<?>> seen, Set<Class<?>> types, Class<?> annotationType) {
+		if (seen.contains(annotationType)) {
+			return;
+		}
+		seen.add(annotationType);
 		for (Method method : annotationType.getDeclaredMethods()) {
 			MergedAnnotations methodAnnotations = MergedAnnotations.from(method);
 			if (methodAnnotations.isPresent(AliasFor.class)) {
-				Class<?> aliasedAnnotation = methodAnnotations.get(AliasFor.class).getClass("annotation");
-				boolean process = (aliasedAnnotation != Annotation.class && !types.contains(aliasedAnnotation));
-				if (process) {
-					types.add(aliasedAnnotation);
-					collectAliasedAnnotations(types, aliasedAnnotation);
+				Class<?> annotationAttribute = methodAnnotations.get(AliasFor.class).getClass("annotation");
+				Class<?> targetAnnotation = (annotationAttribute != Annotation.class
+						? annotationAttribute : annotationType);
+				if (!types.contains(targetAnnotation)) {
+					types.add(targetAnnotation);
+					if (!targetAnnotation.equals(annotationType)) {
+						collectAliasedAnnotations(seen, types, targetAnnotation);
+					}
 				}
 			}
 		}

spring-core/src/test/java/org/springframework/aot/hint/support/RuntimeHintsUtilsTests.java

@@ -53,6 +53,15 @@ void registerAnnotationType() {
 		assertThat(this.hints.proxies().jdkProxies()).isEmpty();
 	}
 
+	@Test
+	void registerAnnotationTypeWithLocalUseOfAliasForRegistersProxy() {
+		RuntimeHintsUtils.registerAnnotation(this.hints, LocalMapping.class);
+		assertThat(this.hints.reflection().typeHints()).singleElement()
+				.satisfies(annotationHint(LocalMapping.class));
+		assertThat(this.hints.proxies().jdkProxies()).singleElement()
+				.satisfies(annotationProxy(LocalMapping.class));
+	}
+
 	@Test
 	void registerAnnotationTypeProxyRegistersJdkProxy() {
 		RuntimeHintsUtils.registerAnnotation(this.hints, RetryInvoker.class);
@@ -108,6 +117,19 @@ static class RetryWithEnabledFlagInvokerClass {
 
 	}
 
+	@Target({ ElementType.TYPE, ElementType.ANNOTATION_TYPE })
+	@Retention(RetentionPolicy.RUNTIME)
+	@Documented
+	@interface LocalMapping {
+
+		@AliasFor("retries")
+		int value() default 0;
+
+		@AliasFor("value")
+		int retries() default 0;
+
+	}
+
 
 	@Target({ ElementType.TYPE, ElementType.ANNOTATION_TYPE })
 	@Retention(RetentionPolicy.RUNTIME)