Rework class objects

Class objects have name "Default" by default
Do not produce synthetic class objects
Class objects have new semantics:
    class "A" has class object "B" if literal "A" can be used as a value of type "B"
Class objects act like ordinary nested objects
    i.e. are accessible from class scope via getClassifier()
Jvm backend: class object fields and class have the name of class object ("Default")
	as opposed to special "OBJECT$" and "object"
Serialization: only the name of class object is needed to serialize data

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/resolve/IDELightClassGenerationSupport.java

@@ -256,11 +256,7 @@ public class IDELightClassGenerationSupport extends LightClassGenerationSupport
     @NotNull
     private static FqName getClassRelativeName(@NotNull JetClassOrObject decompiledClassOrObject) {
         Name name = decompiledClassOrObject.getNameAsName();
-        if (name == null) {
-            assert decompiledClassOrObject instanceof JetObjectDeclaration &&
-                   ((JetObjectDeclaration) decompiledClassOrObject).isClassObject();
-            name = Name.identifier(JvmAbi.CLASS_OBJECT_CLASS_NAME);
-        }
+        assert name != null;
         JetClassOrObject parent = PsiTreeUtil.getParentOfType(decompiledClassOrObject, JetClassOrObject.class, true);
         if (parent == null) {
             assert decompiledClassOrObject.isTopLevel();

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/stubBuilder/ClassClsStubBuilder.kt

@@ -31,7 +31,6 @@ import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.psi.JetDelegationSpecifierList
 import org.jetbrains.kotlin.psi.JetDelegatorToSuperClass
 import org.jetbrains.kotlin.lexer.JetTokens
-import org.jetbrains.kotlin.name.SpecialNames.getClassObjectName
 import org.jetbrains.kotlin.psi.JetClassObject
 import org.jetbrains.kotlin.serialization.deserialization.ProtoContainer
 import org.jetbrains.kotlin.psi.stubs.impl.KotlinModifierListStubImpl
@@ -68,6 +67,7 @@ private class ClassClsStubBuilder(
             supertypeIds
         }
     }
+    private val classObjectName = if (classProto.hasClassObjectName()) c.nameResolver.getName(classProto.getClassObjectName()) else null
 
     private val classOrObjectStub = createClassOrObjectStubAndModifierListStub()
 
@@ -112,8 +112,8 @@ private class ClassClsStubBuilder(
 
     private fun doCreateClassOrObjectStub(parent: StubElement<out PsiElement>): StubElement<out PsiElement> {
         val isClassObject = classKind == ProtoBuf.Class.Kind.CLASS_OBJECT
-        val fqName = if (!isClassObject) outerContext.memberFqNameProvider.getMemberFqName(classId.getRelativeClassName().shortName()) else null
-        val shortName = fqName?.shortName()?.ref()
+        val fqName = outerContext.memberFqNameProvider.getMemberFqName(classId.getRelativeClassName().shortName())
+        val shortName = fqName.shortName()?.ref()
         val superTypeRefs = supertypeIds.filter {
             //TODO: filtering function types should go away
             !KotlinBuiltIns.isExactFunctionType(it.asSingleFqName()) && !KotlinBuiltIns.isExactExtensionFunctionType(it.asSingleFqName())
@@ -132,7 +132,7 @@ private class ClassClsStubBuilder(
                 KotlinClassStubImpl(
                         JetClassElementType.getStubType(classKind == ProtoBuf.Class.Kind.ENUM_ENTRY),
                         parent,
-                        fqName?.ref(),
+                        fqName.ref(),
                         shortName,
                         superTypeRefs,
                         isTrait = classKind == ProtoBuf.Class.Kind.TRAIT,
@@ -181,11 +181,11 @@ private class ClassClsStubBuilder(
     }
 
     private fun createClassObjectStub(classBody: KotlinPlaceHolderStubImpl<JetClassBody>) {
-        if (!classProto.hasClassObject() || classKind == ProtoBuf.Class.Kind.OBJECT) {
+        if (classObjectName == null) {
             return
         }
 
-        val classObjectId = classId.createNestedClassId(getClassObjectName(classId.getRelativeClassName().shortName()))
+        val classObjectId = classId.createNestedClassId(classObjectName)
         createNestedClassStub(classBody, classObjectId)
     }
 
@@ -221,8 +221,11 @@ private class ClassClsStubBuilder(
 
     private fun createInnerAndNestedClasses(classBody: KotlinPlaceHolderStubImpl<JetClassBody>) {
         classProto.getNestedClassNameList().forEach { id ->
-            val nestedClassId = classId.createNestedClassId(c.nameResolver.getName(id))
-            createNestedClassStub(classBody, nestedClassId)
+            val nestedClassName = c.nameResolver.getName(id)
+            if (nestedClassName != classObjectName) {
+                val nestedClassId = classId.createNestedClassId(nestedClassName)
+                createNestedClassStub(classBody, nestedClassId)
+            }
         }
     }
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/stubBuilder/ClsStubBuilderContext.kt

@@ -27,7 +27,6 @@ import org.jetbrains.kotlin.load.kotlin.AbstractBinaryClassAnnotationAndConstant
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.storage.LockBasedStorageManager
 import org.jetbrains.kotlin.load.kotlin.KotlinJvmBinaryClass
-import org.jetbrains.kotlin.name.SpecialNames
 
 
 class ClsStubBuilderComponents(
@@ -42,11 +41,11 @@ class ClsStubBuilderComponents(
     }
 }
 
+//TODO_R: remove?
 class MemberFqNameProvider(val fqName: FqName) {
     fun getMemberFqName(name: Name): FqName = fqName.child(name)
 
-    fun child(name: Name?): MemberFqNameProvider =
-            if (name == null || SpecialNames.isClassObjectName(name)) this else MemberFqNameProvider(fqName.child(name))
+    fun child(name: Name?): MemberFqNameProvider = if (name == null) this else MemberFqNameProvider(fqName.child(name))
 }
 
 trait TypeParameters {

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/stubBuilder/clsStubBuilding.kt

@@ -97,8 +97,7 @@ fun createStubForPackageName(packageDirectiveStub: KotlinPlaceHolderStubImpl<Jet
 }
 
 fun createStubForTypeName(typeClassId: ClassId, parent: StubElement<out PsiElement>): KotlinUserTypeStub {
-    //TODO: should go away with default objects
-    val segments = typeClassId.asSingleFqName().pathSegments().filter { !SpecialNames.isClassObjectName(it) }.toArrayList()
+    val segments = typeClassId.asSingleFqName().pathSegments().toArrayList()
     assert(segments.isNotEmpty())
     val iterator = segments.listIterator(segments.size())
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/textBuilder/DecompiledTextFactory.kt

@@ -148,7 +148,7 @@ private fun buildDecompiledText(packageFqName: FqName, descriptors: List<Declara
                 var firstPassed = false
                 val subindent = indent + "    "
                 val classObject = descriptor.getClassObjectDescriptor()
-                if (classObject != null && !isSyntheticClassObject(classObject)) {
+                if (classObject != null && !descriptor.getKind().isSingleton() && !isSyntheticClassObject(classObject)) {
                     firstPassed = true
                     builder.append(subindent)
                     appendDescriptor(classObject, subindent)
@@ -157,6 +157,9 @@ private fun buildDecompiledText(packageFqName: FqName, descriptors: List<Declara
                     if (member.getContainingDeclaration() != descriptor) {
                         continue
                     }
+                    if (member == classObject) {
+                        continue
+                    }
                     if (member is CallableMemberDescriptor
                         && member.getKind() != CallableMemberDescriptor.Kind.DECLARATION
                         //TODO: not synthesized and component like

idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/DeprecatedAnnotationVisitor.java

@@ -114,16 +114,7 @@ public class DeprecatedAnnotationVisitor extends AfterAnalysisHighlightingVisito
     }
 
     private void checkClassDescriptor(@NotNull JetExpression expression, @NotNull ClassDescriptor target) {
-        // Deprecated for Class, for ClassObject (if reference isn't in UserType or in ModifierList (trait))
-        if (!reportAnnotationIfNeeded(expression, target)) {
-            if (PsiTreeUtil.getParentOfType(expression, JetUserType.class) == null &&
-                PsiTreeUtil.getParentOfType(expression, JetModifierList.class) == null) {
-                ClassDescriptor classObjectDescriptor = target.getClassObjectDescriptor();
-                if (classObjectDescriptor != null) {
-                    reportAnnotationIfNeeded(expression, classObjectDescriptor);
-                }
-            }
-        }
+        reportAnnotationIfNeeded(expression, target);
     }
 
     private void checkPropertyDescriptor(

idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/StubIndexServiceImpl.java

@@ -56,25 +56,11 @@ public class StubIndexServiceImpl implements StubIndexService {
     @Override
     public void indexObject(KotlinObjectStub stub, IndexSink sink) {
         String name = stub.getName();
-        FqName fqName = stub.getFqName();
-
-        if (stub.isClassObject()) {
-            StubElement parentClassStub = stub.getParentStub().getParentStub().getParentStub();
-            assert parentClassStub instanceof KotlinStubWithFqName<?>
-                    : "Something but a class/object is a parent to class object stub: " + parentClassStub;
-
-            name = JvmAbi.CLASS_OBJECT_CLASS_NAME;
-
-            FqName parentFqName = ((KotlinStubWithFqName<?>) parentClassStub).getFqName();
-            if (parentFqName != null) {
-                fqName = parentFqName.child(Name.identifier(name));
-            }
-        }
-
         if (name != null) {
             sink.occurrence(JetClassShortNameIndex.getInstance().getKey(), name);
         }
 
+        FqName fqName = stub.getFqName();
         if (fqName != null) {
             sink.occurrence(JetFullClassNameIndex.getInstance().getKey(), fqName.asString());