Add companion classes to Kotlin reflective hierarchy registration

Fixes: #37957
(cherry picked from commit e185df8)

core/deployment/src/main/java/io/quarkus/deployment/steps/ReflectiveHierarchyStep.java

@@ -1,5 +1,7 @@
 package io.quarkus.deployment.steps;
 
+import static io.quarkus.deployment.steps.KotlinUtil.isKotlinClass;
+
 import java.lang.reflect.Modifier;
 import java.util.ArrayDeque;
 import java.util.Deque;
@@ -27,6 +29,8 @@
 import org.jboss.jandex.VoidType;
 import org.jboss.logging.Logger;
 
+import io.quarkus.deployment.Capabilities;
+import io.quarkus.deployment.Capability;
 import io.quarkus.deployment.annotations.BuildProducer;
 import io.quarkus.deployment.annotations.BuildStep;
 import io.quarkus.deployment.builditem.CombinedIndexBuildItem;
@@ -51,7 +55,7 @@ public ReflectiveHierarchyIgnoreWarningBuildItem ignoreJavaClassWarnings() {
     }
 
     @BuildStep
-    public void build(CombinedIndexBuildItem combinedIndexBuildItem,
+    public void build(CombinedIndexBuildItem combinedIndexBuildItem, Capabilities capabilities,
             List<ReflectiveHierarchyBuildItem> hierarchy,
             List<ReflectiveHierarchyIgnoreWarningBuildItem> ignored,
             List<ReflectiveClassFinalFieldsWritablePredicateBuildItem> finalFieldsWritablePredicates,
@@ -73,7 +77,7 @@ public void build(CombinedIndexBuildItem combinedIndexBuildItem,
         final Deque<ReflectiveHierarchyVisitor> visits = new ArrayDeque<>();
 
         for (ReflectiveHierarchyBuildItem i : hierarchy) {
-            addReflectiveHierarchy(combinedIndexBuildItem,
+            addReflectiveHierarchy(combinedIndexBuildItem, capabilities,
                     i,
                     i.hasSource() ? i.getSource() : i.getType().name().toString(),
                     i.getType(),
@@ -128,7 +132,7 @@ private void removeIgnored(Map<DotName, Set<String>> unindexedClasses,
     }
 
     private void addReflectiveHierarchy(CombinedIndexBuildItem combinedIndexBuildItem,
-            ReflectiveHierarchyBuildItem reflectiveHierarchyBuildItem, String source, Type type,
+            Capabilities capabilities, ReflectiveHierarchyBuildItem reflectiveHierarchyBuildItem, String source, Type type,
             Set<DotName> processedReflectiveHierarchies, Map<DotName, Set<String>> unindexedClasses,
             Predicate<ClassInfo> finalFieldsWritable, BuildProducer<ReflectiveClassBuildItem> reflectiveClass,
             Deque<ReflectiveHierarchyVisitor> visits) {
@@ -142,45 +146,50 @@ private void addReflectiveHierarchy(CombinedIndexBuildItem combinedIndexBuildIte
                 return;
             }
 
-            addClassTypeHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source, type.name(), type.name(),
+            addClassTypeHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source, type.name(),
+                    type.name(),
                     processedReflectiveHierarchies, unindexedClasses,
                     finalFieldsWritable, reflectiveClass, visits);
 
             for (ClassInfo subclass : combinedIndexBuildItem.getIndex().getAllKnownSubclasses(type.name())) {
-                addClassTypeHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source, subclass.name(),
+                addClassTypeHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source,
+                        subclass.name(),
                         subclass.name(),
                         processedReflectiveHierarchies,
                         unindexedClasses, finalFieldsWritable, reflectiveClass, visits);
             }
             for (ClassInfo subclass : combinedIndexBuildItem.getIndex().getAllKnownImplementors(type.name())) {
-                addClassTypeHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source, subclass.name(),
+                addClassTypeHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source,
+                        subclass.name(),
                         subclass.name(),
                         processedReflectiveHierarchies,
                         unindexedClasses, finalFieldsWritable, reflectiveClass, visits);
             }
         } else if (type instanceof ArrayType) {
-            visits.addLast(() -> addReflectiveHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source,
+            visits.addLast(() -> addReflectiveHierarchy(combinedIndexBuildItem, capabilities,
+                    reflectiveHierarchyBuildItem, source,
                     type.asArrayType().constituent(),
                     processedReflectiveHierarchies,
                     unindexedClasses, finalFieldsWritable, reflectiveClass, visits));
         } else if (type instanceof ParameterizedType) {
             if (!reflectiveHierarchyBuildItem.getIgnoreTypePredicate().test(type.name())) {
-                addClassTypeHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source, type.name(),
+                addClassTypeHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source, type.name(),
                         type.name(),
                         processedReflectiveHierarchies,
                         unindexedClasses, finalFieldsWritable, reflectiveClass, visits);
             }
             final ParameterizedType parameterizedType = (ParameterizedType) type;
             for (Type typeArgument : parameterizedType.arguments()) {
                 visits.addLast(
-                        () -> addReflectiveHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source, typeArgument,
+                        () -> addReflectiveHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source,
+                                typeArgument,
                                 processedReflectiveHierarchies,
                                 unindexedClasses, finalFieldsWritable, reflectiveClass, visits));
             }
         }
     }
 
-    private void addClassTypeHierarchy(CombinedIndexBuildItem combinedIndexBuildItem,
+    private void addClassTypeHierarchy(CombinedIndexBuildItem combinedIndexBuildItem, Capabilities capabilities,
             ReflectiveHierarchyBuildItem reflectiveHierarchyBuildItem,
             String source,
             DotName name,
@@ -223,7 +232,7 @@ private void addClassTypeHierarchy(CombinedIndexBuildItem combinedIndexBuildItem
             return;
         }
 
-        visits.addLast(() -> addClassTypeHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source,
+        visits.addLast(() -> addClassTypeHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source,
                 info.superName(), initialName,
                 processedReflectiveHierarchies,
                 unindexedClasses, finalFieldsWritable, reflectiveClass, visits));
@@ -237,7 +246,8 @@ private void addClassTypeHierarchy(CombinedIndexBuildItem combinedIndexBuildItem
             }
             final Type fieldType = getFieldType(combinedIndexBuildItem, initialName, info, field);
             visits.addLast(
-                    () -> addReflectiveHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source, fieldType,
+                    () -> addReflectiveHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source,
+                            fieldType,
                             processedReflectiveHierarchies,
                             unindexedClasses, finalFieldsWritable, reflectiveClass, visits));
         }
@@ -249,11 +259,30 @@ private void addClassTypeHierarchy(CombinedIndexBuildItem combinedIndexBuildItem
                     method.returnType().kind() == Kind.VOID) {
                 continue;
             }
-            visits.addLast(() -> addReflectiveHierarchy(combinedIndexBuildItem, reflectiveHierarchyBuildItem, source,
+            visits.addLast(() -> addReflectiveHierarchy(combinedIndexBuildItem, capabilities,
+                    reflectiveHierarchyBuildItem, source,
                     method.returnType(),
                     processedReflectiveHierarchies,
                     unindexedClasses, finalFieldsWritable, reflectiveClass, visits));
         }
+
+        // for Kotlin classes, we need to register the nested classes as well because companion classes are very often necessary at runtime
+        if (capabilities.isPresent(Capability.KOTLIN) && isKotlinClass(info)) {
+            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+            try {
+                Class<?>[] declaredClasses = classLoader.loadClass(info.name().toString()).getDeclaredClasses();
+                for (Class<?> clazz : declaredClasses) {
+                    DotName dotName = DotName.createSimple(clazz.getName());
+                    addClassTypeHierarchy(combinedIndexBuildItem, capabilities, reflectiveHierarchyBuildItem, source,
+                            dotName, dotName,
+                            processedReflectiveHierarchies, unindexedClasses,
+                            finalFieldsWritable, reflectiveClass, visits);
+                }
+            } catch (ClassNotFoundException e) {
+                log.warnf(e, "Failed to load Class %s", info.name().toString());
+            }
+
+        }
     }
 
     private static Type getFieldType(CombinedIndexBuildItem combinedIndexBuildItem, DotName initialName, ClassInfo info,

integration-tests/resteasy-reactive-kotlin/standard/src/main/kotlin/io/quarkus/it/resteasy/reactive/kotlin/CompanionResource.kt

@@ -0,0 +1,19 @@
+package io.quarkus.it.resteasy.reactive.kotlin
+
+import jakarta.ws.rs.GET
+import jakarta.ws.rs.Path
+import jakarta.ws.rs.Produces
+import jakarta.ws.rs.core.MediaType
+
+@Path("/companion")
+class CompanionResource {
+    @Path("success")
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    fun success() = ResponseData.success()
+
+    @Path("failure")
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    fun failure() = ResponseData.failure("error")
+}

integration-tests/resteasy-reactive-kotlin/standard/src/main/kotlin/io/quarkus/it/resteasy/reactive/kotlin/ResponseData.kt

@@ -0,0 +1,17 @@
+package io.quarkus.it.resteasy.reactive.kotlin
+
+class ResponseData<T>(
+    val code: Int = STATUS_CODE.SUCCESS.code,
+    val msg: String = "",
+    val data: T? = null,
+) {
+    companion object {
+        fun success() = ResponseData<Unit>()
+        fun failure(msg: String) = ResponseData<Unit>(code = STATUS_CODE.ERROR.code, msg = msg)
+    }
+}
+
+enum class STATUS_CODE(val code: Int) {
+    SUCCESS(200),
+    ERROR(500)
+}

integration-tests/resteasy-reactive-kotlin/standard/src/test/kotlin/io/quarkus/it/resteasy/reactive/kotlin/CompanionIT.kt

@@ -0,0 +1,5 @@
+package io.quarkus.it.resteasy.reactive.kotlin
+
+import io.quarkus.test.junit.QuarkusIntegrationTest
+
+@QuarkusIntegrationTest class CompanionIT : CompanionTest() {}

integration-tests/resteasy-reactive-kotlin/standard/src/test/kotlin/io/quarkus/it/resteasy/reactive/kotlin/CompanionTest.kt

@@ -0,0 +1,29 @@
+package io.quarkus.it.resteasy.reactive.kotlin
+
+import io.quarkus.test.junit.QuarkusTest
+import io.restassured.module.kotlin.extensions.Then
+import io.restassured.module.kotlin.extensions.When
+import org.hamcrest.Matchers.*
+import org.junit.jupiter.api.Test
+
+@QuarkusTest
+class CompanionTest {
+
+    @Test
+    fun testSuccessResponseData() {
+        When { get("/companion/success") } Then
+            {
+                statusCode(200)
+                body(containsString("200"))
+            }
+    }
+
+    @Test
+    fun testFailureResponseData() {
+        When { get("/companion/failure") } Then
+            {
+                statusCode(200)
+                body(containsString("500"), containsString("error"))
+            }
+    }
+}