Change object deserialization strategy

Objects now have synthetic class objects in deserialization as well. "Class"
proto message now can have a synthetic class object proto within, if it's not
contained in any external class file, which is the case with objects. Drop
"class_object_present" field from binary format, since its value is equivalent
to the presence of "class_object" field

compiler/backend/src/org/jetbrains/jet/codegen/NamespaceCodegen.java

@@ -210,14 +210,12 @@ public class NamespaceCodegen extends MemberCodegen {
      * @param namespaceFiles all files should have same package name
      * @return
      */
-    public static boolean shouldGenerateNSClass(Collection<JetFile> namespaceFiles) {
+    public static boolean shouldGenerateNSClass(@NotNull Collection<JetFile> namespaceFiles) {
         checkAllFilesHaveSameNamespace(namespaceFiles);
 
         for (JetFile file : namespaceFiles) {
             for (JetDeclaration declaration : file.getDeclarations()) {
-                if (declaration instanceof JetProperty ||
-                    declaration instanceof JetNamedFunction ||
-                    declaration instanceof JetObjectDeclaration) {
+                if (declaration instanceof JetProperty || declaration instanceof JetNamedFunction) {
                     return true;
                 }
             }

compiler/frontend/serialization/src/descriptors.proto

@@ -110,6 +110,15 @@ message Class {
 
   required int32 fq_name = 3;
 
+  message ClassObject {
+    // If this field is present, it contains serialized data for a synthetic class object, for which there's no class file.
+    // Otherwise class object was compiled to a separate class file and serialized data can be found in the annotation on that class
+    optional Class data = 1;
+  }
+
+  // This field is present if and only if the class has a class object. Its proto should be found either here or in the separate file
+  optional ClassObject class_object = 4;
+
   repeated TypeParameter type_parameter = 5;
   repeated Type supertype = 6;
 
@@ -118,8 +127,6 @@ message Class {
   repeated int32 nested_class_name = 7;
   repeated int32 nested_object_name = 8;
 
-  optional bool class_object_present = 9 [default = false];
-
   repeated Callable member = 11;
 
   repeated int32 enum_entry = 12;

compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/AbstractDescriptorFinder.java

@@ -26,7 +26,6 @@ import org.jetbrains.jet.storage.MemoizedFunctionToNullable;
 import org.jetbrains.jet.storage.StorageManager;
 
 public abstract class AbstractDescriptorFinder implements DescriptorFinder {
-
     private final MemoizedFunctionToNullable<ClassId, ClassDescriptor> findClass;
     private final AnnotationDeserializer annotationDeserializer;
 
@@ -46,7 +45,8 @@ public abstract class AbstractDescriptorFinder implements DescriptorFinder {
 
                 AbstractDescriptorFinder _this = AbstractDescriptorFinder.this;
                 ClassDescriptor classDescriptor =
-                        new DeserializedClassDescriptor(storageManager, _this.annotationDeserializer, _this, classData);
+                        new DeserializedClassDescriptor(storageManager, _this.annotationDeserializer, _this, classData.getNameResolver(),
+                                                        classData.getClassProto());
                 classDescriptorCreated(classDescriptor);
                 return classDescriptor;
             }

compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/DescriptorSerializer.java

@@ -29,17 +29,14 @@ import org.jetbrains.jet.renderer.DescriptorRenderer;
 
 import java.util.*;
 
-import static org.jetbrains.jet.lang.resolve.DescriptorUtils.getEnumEntriesScope;
-import static org.jetbrains.jet.lang.resolve.DescriptorUtils.isTopLevelOrInnerClass;
+import static org.jetbrains.jet.lang.resolve.DescriptorUtils.*;
 
 public class DescriptorSerializer {
 
     private static final DescriptorRenderer RENDERER = DescriptorRenderer.STARTS_FROM_NAME;
     private static final Comparator<DeclarationDescriptor> DESCRIPTOR_COMPARATOR = new Comparator<DeclarationDescriptor>() {
         @Override
-        public int compare(
-                DeclarationDescriptor o1, DeclarationDescriptor o2
-        ) {
+        public int compare(@NotNull DeclarationDescriptor o1, @NotNull DeclarationDescriptor o2) {
             int names = o1.getName().compareTo(o2.getName());
             if (names != 0) return names;
 
@@ -134,9 +131,9 @@ public class DescriptorSerializer {
             builder.addNestedObjectName(nameIndex);
         }
 
-        if (classDescriptor.getClassObjectDescriptor() != null) {
-            // false is default
-            builder.setClassObjectPresent(true);
+        ClassDescriptor classObject = classDescriptor.getClassObjectDescriptor();
+        if (classObject != null) {
+            builder.setClassObject(classObjectProto(classObject));
         }
 
         if (classDescriptor.getKind() == ClassKind.ENUM_CLASS) {
@@ -150,6 +147,15 @@ public class DescriptorSerializer {
         return builder;
     }
 
+    @NotNull
+    private ProtoBuf.Class.ClassObject classObjectProto(@NotNull ClassDescriptor classObject) {
+        if (isObject(classObject.getContainingDeclaration())) {
+            return ProtoBuf.Class.ClassObject.newBuilder().setData(classProto(classObject)).build();
+        }
+
+        return ProtoBuf.Class.ClassObject.getDefaultInstance();
+    }
+
     @NotNull
     public ProtoBuf.Callable.Builder callableProto(@NotNull CallableMemberDescriptor descriptor) {
         ProtoBuf.Callable.Builder builder = ProtoBuf.Callable.newBuilder();

compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/descriptors/DeserializedClassDescriptor.java

@@ -48,6 +48,7 @@ public class DeserializedClassDescriptor extends AbstractClassDescriptor impleme
 
     private final ClassId classId;
     private final ProtoBuf.Class classProto;
+    private final StorageManager storageManager;
     private final TypeDeserializer typeDeserializer;
     private final DescriptorDeserializer deserializer;
     private final DeserializedMemberScope memberScope;
@@ -74,14 +75,13 @@ public class DeserializedClassDescriptor extends AbstractClassDescriptor impleme
             @NotNull StorageManager storageManager,
             @NotNull AnnotationDeserializer annotationResolver,
             @NotNull DescriptorFinder descriptorFinder,
-            @NotNull ClassData classData
+            @NotNull NameResolver nameResolver,
+            @NotNull ProtoBuf.Class classProto
     ) {
-        super(storageManager,
-              classData.getNameResolver().getClassId(classData.getClassProto().getFqName()).getRelativeClassName().shortName());
-        NameResolver nameResolver = classData.getNameResolver();
-        this.classProto = classData.getClassProto();
-
+        super(storageManager, nameResolver.getClassId(classProto.getFqName()).getRelativeClassName().shortName());
+        this.classProto = classProto;
         this.classId = nameResolver.getClassId(classProto.getFqName());
+        this.storageManager = storageManager;
         this.descriptorFinder = descriptorFinder;
 
         TypeDeserializer notNullTypeDeserializer = new TypeDeserializer(storageManager, null, nameResolver,
@@ -238,7 +238,7 @@ public class DeserializedClassDescriptor extends AbstractClassDescriptor impleme
 
     @Nullable
     private ClassDescriptor computeClassObjectDescriptor() {
-        if (!classProto.getClassObjectPresent()) {
+        if (!classProto.hasClassObject()) {
             return null;
         }
 
@@ -252,6 +252,16 @@ public class DeserializedClassDescriptor extends AbstractClassDescriptor impleme
             return classObject;
         }
 
+        if (getKind() == ClassKind.OBJECT) {
+            ProtoBuf.Class.ClassObject classObjectProto = classProto.getClassObject();
+            if (!classObjectProto.hasData()) {
+                throw new IllegalStateException("Object should have a serialized class object: " + classId);
+            }
+
+            return new DeserializedClassDescriptor(storageManager, annotationDeserializer, descriptorFinder, deserializer.getNameResolver(),
+                                                   classObjectProto.getData());
+        }
+
         return descriptorFinder.findClass(classId.createNestedClassId(getClassObjectName(getName())));
     }
 

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/scope/JavaPackageScope.java

@@ -55,11 +55,7 @@ public final class JavaPackageScope extends JavaBaseScope {
 
     @Override
     public ClassifierDescriptor getClassifier(@NotNull Name name) {
-        ClassDescriptor classDescriptor = memberResolver.resolveClass(packageFQN.child(name), IGNORE_KOTLIN_SOURCES);
-        if (classDescriptor == null || classDescriptor.getKind().isSingleton()) {
-            return null;
-        }
-        return classDescriptor;
+        return memberResolver.resolveClass(packageFQN.child(name), IGNORE_KOTLIN_SOURCES);
     }
 
     @Override

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/kotlin/DeserializedDescriptorResolver.java

@@ -18,6 +18,7 @@ package org.jetbrains.jet.lang.resolve.kotlin;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.descriptors.serialization.ClassData;
 import org.jetbrains.jet.descriptors.serialization.ClassId;
 import org.jetbrains.jet.descriptors.serialization.DescriptorFinder;
 import org.jetbrains.jet.descriptors.serialization.JavaProtoBufUtil;
@@ -97,15 +98,22 @@ public final class DeserializedDescriptorResolver {
     @Nullable
     public ClassDescriptor resolveClass(@NotNull KotlinJvmBinaryClass kotlinClass) {
         String[] data = readData(kotlinClass);
-        return data == null ? null : new DeserializedClassDescriptor(storageManager, annotationDeserializer, javaDescriptorFinder,
-                                                                     JavaProtoBufUtil.readClassDataFrom(data));
+        if (data != null) {
+            ClassData classData = JavaProtoBufUtil.readClassDataFrom(data);
+            return new DeserializedClassDescriptor(storageManager, annotationDeserializer, javaDescriptorFinder,
+                                                   classData.getNameResolver(), classData.getClassProto());
+        }
+        return null;
     }
 
     @Nullable
     public JetScope createKotlinPackageScope(@NotNull NamespaceDescriptor descriptor, @NotNull KotlinJvmBinaryClass kotlinClass) {
         String[] data = readData(kotlinClass);
-        return data == null ? null : new DeserializedPackageMemberScope(storageManager, descriptor, annotationDeserializer,
-                                                                        javaDescriptorFinder, JavaProtoBufUtil.readPackageDataFrom(data));
+        if (data != null) {
+            return new DeserializedPackageMemberScope(storageManager, descriptor, annotationDeserializer, javaDescriptorFinder,
+                                                      JavaProtoBufUtil.readPackageDataFrom(data));
+        }
+        return null;
     }
 
     @Nullable