[FE] Call SealedClassInheritorsProvider only for sealed classes

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java

@@ -54,6 +54,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 
+import static kotlin.collections.CollectionsKt.emptyList;
 import static kotlin.collections.CollectionsKt.firstOrNull;
 import static org.jetbrains.kotlin.descriptors.DescriptorVisibilities.PRIVATE;
 import static org.jetbrains.kotlin.descriptors.DescriptorVisibilities.PUBLIC;
@@ -270,7 +271,14 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
         );
 
         boolean freedomForSealedInterfacesSupported = c.getLanguageVersionSettings().supportsFeature(LanguageFeature.AllowSealedInheritorsInDifferentFilesOfSamePackage);
-        this.sealedSubclasses = storageManager.createLazyValue(() -> c.getSealedClassInheritorsProvider().computeSealedSubclasses(this, freedomForSealedInterfacesSupported));
+        this.sealedSubclasses =
+            storageManager.createLazyValue(() -> {
+                if (getModality() == Modality.SEALED) {
+                    return c.getSealedClassInheritorsProvider().computeSealedSubclasses(this, freedomForSealedInterfacesSupported);
+                } else {
+                    return Collections.emptyList();
+                }
+        });
     }
 
     private static boolean isIllegalInner(@NotNull DeclarationDescriptor descriptor) {

core/descriptors/src/org/jetbrains/kotlin/resolve/SealedClassInheritorsProvider.kt

@@ -13,6 +13,9 @@ import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 
 abstract class SealedClassInheritorsProvider {
+    /**
+     * This method may be called by compiler only for classes/interfaces with sealed modality
+     */
     abstract fun computeSealedSubclasses(
         sealedClass: ClassDescriptor,
         freedomForSealedInterfacesSupported: Boolean

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/CommonizedClassDescriptor.kt

@@ -54,7 +54,11 @@ class CommonizedClassDescriptor(
     private val typeConstructor = CommonizedClassTypeConstructor(targetComponents, cirSupertypes)
     private val sealedSubclasses = targetComponents.storageManager.createLazyValue {
         // TODO: pass proper language version settings
-        SealedClassInheritorsProviderImpl.computeSealedSubclasses(this, freedomForSealedInterfacesSupported = false)
+        if (modality == Modality.SEALED) {
+            SealedClassInheritorsProviderImpl.computeSealedSubclasses(this, freedomForSealedInterfacesSupported = false)
+        } else {
+            emptyList()
+        }
     }
 
     private val declaredTypeParametersAndTypeParameterResolver = targetComponents.storageManager.createLazyValue {