Introduce ClassDescriptor#getDefaultObjectDescriptor()

ClassDescriptor#getClassObjectDescriptor (with old semantics) is now a utility
Process usages and replace with calls to a new method where appropriate

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaClassDescriptor.kt

@@ -85,8 +85,7 @@ class LazyJavaClassDescriptor(
 
     override fun getUnsubstitutedPrimaryConstructor(): ConstructorDescriptor? = null
 
-    override fun getClassObjectDescriptor(): ClassDescriptor? = null
-    override fun getClassObjectType(): JetType? = getClassObjectDescriptor()?.let { d -> d.getDefaultType() }
+    override fun getDefaultObjectDescriptor(): ClassDescriptor? = null
 
     override fun getConstructors() = scopeForMemberLookup.constructors()
 

core/descriptors/src/org/jetbrains/kotlin/descriptors/ClassDescriptor.java

@@ -60,8 +60,11 @@ public interface ClassDescriptor extends ClassifierDescriptor, MemberDescriptor,
     @Override
     JetType getClassObjectType();
 
+    /**
+     * @return nested object declared as 'default' if one is present.
+     */
     @Nullable
-    ClassDescriptor getClassObjectDescriptor();
+    ClassDescriptor getDefaultObjectDescriptor();
 
     @NotNull
     ClassKind getKind();

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/AbstractClassDescriptor.java

@@ -21,6 +21,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.name.Name;
+import org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilPackage;
 import org.jetbrains.kotlin.resolve.scopes.InnerClassesScopeWrapper;
 import org.jetbrains.kotlin.resolve.scopes.JetScope;
 import org.jetbrains.kotlin.resolve.scopes.SubstitutingScope;
@@ -31,8 +32,6 @@ import org.jetbrains.kotlin.types.*;
 import java.util.List;
 import java.util.Map;
 
-import static org.jetbrains.kotlin.resolve.DescriptorUtils.isEnumClass;
-
 public abstract class AbstractClassDescriptor implements ClassDescriptor {
     private final Name name;
     protected final NotNullLazyValue<JetType> defaultType;
@@ -79,7 +78,7 @@ public abstract class AbstractClassDescriptor implements ClassDescriptor {
     @Nullable
     @Override
     public JetType getClassObjectType() {
-        ClassDescriptor classObject = getClassObjectDescriptor();
+        ClassDescriptor classObject = DescriptorUtilPackage.getClassObjectDescriptor(this);
         return classObject == null ? null : classObject.getDefaultType();
     }
 

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ClassDescriptorImpl.java

@@ -101,7 +101,7 @@ public class ClassDescriptorImpl extends ClassDescriptorBase {
 
     @Nullable
     @Override
-    public ClassDescriptor getClassObjectDescriptor() {
+    public ClassDescriptor getDefaultObjectDescriptor() {
         return null;
     }
 

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/EnumEntrySyntheticClassDescriptor.java

@@ -47,7 +47,6 @@ public class EnumEntrySyntheticClassDescriptor extends ClassDescriptorBase {
     private final ConstructorDescriptor primaryConstructor;
     private final JetScope scope;
     private final JetScope staticScope = new StaticScopeForKotlinClass(this);
-    private final ClassDescriptor classObjectDescriptor;
     private final NotNullLazyValue<Collection<Name>> enumMemberNames;
 
     /**
@@ -88,8 +87,6 @@ public class EnumEntrySyntheticClassDescriptor extends ClassDescriptorBase {
         ConstructorDescriptorImpl primaryConstructor = DescriptorFactory.createPrimaryConstructorForObject(this, source);
         primaryConstructor.setReturnType(getDefaultType());
         this.primaryConstructor = primaryConstructor;
-
-        this.classObjectDescriptor = containingClass;
     }
 
     @NotNull
@@ -118,8 +115,8 @@ public class EnumEntrySyntheticClassDescriptor extends ClassDescriptorBase {
 
     @Nullable
     @Override
-    public ClassDescriptor getClassObjectDescriptor() {
-        return classObjectDescriptor;
+    public ClassDescriptor getDefaultObjectDescriptor() {
+        return null;
     }
 
     @NotNull

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/LazySubstitutingClassDescriptor.java

@@ -169,8 +169,8 @@ public class LazySubstitutingClassDescriptor implements ClassDescriptor {
     }
 
     @Override
-    public ClassDescriptor getClassObjectDescriptor() {
-        return original.getClassObjectDescriptor();
+    public ClassDescriptor getDefaultObjectDescriptor() {
+        return original.getDefaultObjectDescriptor();
     }
 
     @NotNull

core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.java

@@ -320,10 +320,6 @@ public class DescriptorUtils {
         return superClassDescriptor.equals(KotlinBuiltIns.getInstance().getAny());
     }
 
-    public static boolean isSyntheticClassObject(@NotNull DeclarationDescriptor descriptor) {
-        return isClassObject(descriptor) && isSingleton(descriptor.getContainingDeclaration());
-    }
-
     @NotNull
     public static Visibility getDefaultConstructorVisibility(@NotNull ClassDescriptor classDescriptor) {
         ClassKind classKind = classDescriptor.getKind();
@@ -337,11 +333,6 @@ public class DescriptorUtils {
         return Visibilities.PUBLIC;
     }
 
-    @NotNull
-    public static Visibility getSyntheticClassObjectVisibility() {
-        return Visibilities.PUBLIC;
-    }
-
     @Nullable
     public static ClassDescriptor getInnerClassByName(@NotNull ClassDescriptor classDescriptor, @NotNull String innerClassName) {
         ClassifierDescriptor classifier = classDescriptor.getDefaultType().getMemberScope().getClassifier(Name.identifier(innerClassName));

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

@@ -22,12 +22,7 @@ import org.jetbrains.kotlin.descriptors.ClassKind.*
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.ClassId
 
-public fun ClassDescriptor.getClassObjectReferenceTarget(): ClassDescriptor {
-    val classObjectDescriptor = getClassObjectDescriptor()
-    return if (classObjectDescriptor == null || hasSyntheticClassObject()) this else classObjectDescriptor
-}
-
-public fun ClassDescriptor.hasSyntheticClassObject(): Boolean = getKind() in setOf(ENUM_ENTRY, OBJECT)
+public fun ClassDescriptor.getClassObjectReferenceTarget(): ClassDescriptor = getDefaultObjectDescriptor() ?: this
 
 public fun DeclarationDescriptor.getImportableDescriptor(): DeclarationDescriptor {
     return when {
@@ -59,4 +54,18 @@ public val ClassDescriptor.classId: ClassId
             return owner.classId.createNestedClassId(getName())
         }
         throw IllegalStateException("Illegal container: $owner")
+    }
+
+/** If a literal of this class can be used as a value returns the class which represents the type of this value */
+public val ClassDescriptor.classObjectDescriptor: ClassDescriptor?
+    get() {
+        return when (this.getKind()) {
+            CLASS_OBJECT, OBJECT -> this
+            ENUM_ENTRY -> {
+                val container = this.getContainingDeclaration()
+                assert(container is ClassDescriptor && container.getKind() == ENUM_CLASS)
+                container as ClassDescriptor
+            }
+            else -> getDefaultObjectDescriptor()
+        }
     }

core/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.java

@@ -130,8 +130,8 @@ public class DescriptorSerializer {
             }
         }
 
-        ClassDescriptor classObject = classDescriptor.getClassObjectDescriptor();
-        if (classObject != null && isClassObject(classObject)) {
+        ClassDescriptor classObject = classDescriptor.getDefaultObjectDescriptor();
+        if (classObject != null) {
             builder.setClassObjectName(stringTable.getSimpleNameIndex(classObject.getName()));
         }
 

core/serialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt

@@ -110,16 +110,13 @@ public class DeserializedClassDescriptor(
     }
 
     private fun computeClassObjectDescriptor(): ClassDescriptor? {
-        if (getKind() == ClassKind.OBJECT || getKind() == ClassKind.CLASS_OBJECT) {
-            return this
-        }
         if (!classProto.hasClassObjectName()) return null
 
         val classObjectName = c.nameResolver.getName(classProto.getClassObjectName())
         return memberScope.getClassifier(classObjectName) as? ClassDescriptor
     }
 
-    override fun getClassObjectDescriptor(): ClassDescriptor? = classObjectDescriptor()
+    override fun getDefaultObjectDescriptor(): ClassDescriptor? = classObjectDescriptor()
 
     private fun computeSuperTypes(): Collection<JetType> {
         val supertypes = ArrayList<JetType>(classProto.getSupertypeCount())