[HHH-19586] Support @IdClass in Panache 2 repositories

Author: FroMage

tooling/metamodel-generator/src/main/java/org/hibernate/processor/annotation/AnnotationMetaEntity.java

@@ -95,6 +95,7 @@
 import static org.hibernate.processor.util.TypeUtils.getAnnotationMirror;
 import static org.hibernate.processor.util.TypeUtils.getAnnotationValue;
 import static org.hibernate.processor.util.TypeUtils.getGeneratedClassFullyQualifiedName;
+import static org.hibernate.processor.util.TypeUtils.getInheritedAnnotationMirror;
 import static org.hibernate.processor.util.TypeUtils.hasAnnotation;
 import static org.hibernate.processor.util.TypeUtils.implementsInterface;
 import static org.hibernate.processor.util.TypeUtils.primitiveClassMatchesKind;
@@ -703,9 +704,20 @@ else if ( idType != null && finalPrimaryEntity != null ) {
 	}
 
 	private @Nullable TypeMirror findIdType() {
-		Element idMember = findIdMember();
 		TypeElement primaryEntityForTest = primaryEntity;
-		if ( idMember != null && primaryEntityForTest != null ) {
+		if ( primaryEntityForTest == null ) {
+			return null;
+		}
+		AnnotationMirror idClass = getInheritedAnnotationMirror( this.context.getElementUtils(), primaryEntityForTest, ID_CLASS );
+		if ( idClass != null ) {
+			AnnotationValue value = getAnnotationValue(idClass, "value" );
+			// I don't think this can have a null value
+			if ( value != null ) {
+				return (TypeMirror) value.getValue();
+			}
+		}
+		Element idMember = findIdMember();
+		if ( idMember != null ) {
 			TypeMirror typedIdMember = this.context.getTypeUtils().asMemberOf((DeclaredType) primaryEntityForTest.asType(), idMember);
 			return switch(typedIdMember.getKind()) {
 				case ARRAY, DECLARED, BOOLEAN, BYTE, CHAR, SHORT, INT, LONG, FLOAT, DOUBLE -> typedIdMember;

tooling/metamodel-generator/src/main/java/org/hibernate/processor/util/TypeUtils.java

@@ -27,6 +27,7 @@
 import javax.lang.model.type.TypeVariable;
 import javax.lang.model.type.WildcardType;
 import javax.lang.model.util.ElementFilter;
+import javax.lang.model.util.Elements;
 import javax.lang.model.util.SimpleTypeVisitor8;
 import javax.tools.Diagnostic;
 import java.util.HashMap;
@@ -247,6 +248,26 @@ public static boolean isAnnotationMirrorOfType(AnnotationMirror annotationMirror
 		return null;
 	}
 
+	/**
+	 * Checks whether the {@code Element} hosts the annotation (directly or inherited) with the given fully qualified class name.
+	 *
+	 * @param element the element to check for the hosted annotation
+	 * @param qualifiedName the fully qualified class name of the annotation to check for
+	 *
+	 * @return the annotation mirror for the specified annotation class from the {@code Element} or {@code null} in case
+	 *         the {@code TypeElement} does not host the specified annotation (directly or inherited).
+	 */
+	public static @Nullable AnnotationMirror getInheritedAnnotationMirror(Elements elements, Element element, String qualifiedName) {
+		assert element != null;
+		assert qualifiedName != null;
+		for ( AnnotationMirror mirror : elements.getAllAnnotationMirrors(element) ) {
+			if ( isAnnotationMirrorOfType( mirror, qualifiedName ) ) {
+				return mirror;
+			}
+		}
+		return null;
+	}
+
 	public static boolean hasAnnotation(Element element, String qualifiedName) {
 		return getAnnotationMirror( element, qualifiedName ) != null;
 	}