Delete kotlin.jvm.internal.KObject

It was supposed to be used in reflection but the benefits do not outweigh the
cost of KT-6951

 #KT-3223 Fixed
 #KT-6951 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java

@@ -23,13 +23,13 @@ import com.intellij.util.ArrayUtil;
 import kotlin.*;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension;
 import org.jetbrains.kotlin.backend.common.CodegenUtil;
 import org.jetbrains.kotlin.backend.common.CodegenUtilKt;
 import org.jetbrains.kotlin.backend.common.DataClassMethodGenerator;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
 import org.jetbrains.kotlin.codegen.binding.MutableClosure;
 import org.jetbrains.kotlin.codegen.context.*;
+import org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension;
 import org.jetbrains.kotlin.codegen.signature.BothSignatureWriter;
 import org.jetbrains.kotlin.codegen.state.GenerationState;
 import org.jetbrains.kotlin.codegen.state.JetTypeMapper;
@@ -282,34 +282,16 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         sw.writeSuperclassEnd();
 
         List<JetType> interfaceSupertypes = Lists.newArrayList();
-        boolean explicitKObject = false;
 
         for (JetDelegationSpecifier specifier : myClass.getDelegationSpecifiers()) {
             JetType superType = bindingContext.get(BindingContext.TYPE, specifier.getTypeReference());
             assert superType != null : "No supertype for class: " + myClass.getText();
-            ClassifierDescriptor classifierDescriptor = superType.getConstructor().getDeclarationDescriptor();
+            if (isInterface(superType.getConstructor().getDeclarationDescriptor())) {
-            if (classifierDescriptor instanceof ClassDescriptor) {
+                interfaceSupertypes.add(superType);
-                ClassDescriptor superClassDescriptor = (ClassDescriptor) classifierDescriptor;
-                if (isInterface(superClassDescriptor)) {
-                    interfaceSupertypes.add(superType);
-
-                    if (JvmAbi.K_OBJECT.equalsTo(DescriptorUtils.getFqName(superClassDescriptor))) {
-                        explicitKObject = true;
-                    }
-                }
             }
         }
 
         LinkedHashSet<String> superInterfaces = new LinkedHashSet<String>();
-        if (!explicitKObject && !isInterface(descriptor)) {
-            Type kObject = asmTypeByFqNameWithoutInnerClasses(JvmAbi.K_OBJECT);
-            sw.writeInterface();
-            sw.writeClassBegin(kObject);
-            sw.writeClassEnd();
-            sw.writeInterfaceEnd();
-            superInterfaces.add(kObject.getInternalName());
-        }
-
         for (JetType supertype : interfaceSupertypes) {
             sw.writeInterface();
             Type jvmName = typeMapper.mapSupertype(supertype, sw);
@@ -318,8 +300,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         }
 
         return new JvmClassSignature(classAsmType.getInternalName(), superClassAsmType.getInternalName(),
-                                     new ArrayList<String>(superInterfaces),
+                                     new ArrayList<String>(superInterfaces), sw.makeJavaGenericSignature());
-                                     sw.makeJavaGenericSignature());
     }
 
     protected void getSuperClass() {

compiler/testData/asJava/lightClasses/delegation/ExternalAnnotations.java

@@ -1,4 +1,4 @@
-public final class WithPlatformTypes implements kotlin.jvm.internal.KObject, java.lang.Iterable<java.lang.String> {
+public final class WithPlatformTypes implements java.lang.Iterable<java.lang.String> {
     public WithPlatformTypes(@org.jetbrains.annotations.NotNull java.lang.Iterable<java.lang.String> i) { /* compiled code */ }
 
     @org.jetbrains.annotations.NotNull

compiler/testData/asJava/lightClasses/delegation/Function.java

@@ -1,4 +1,4 @@
-public final class Derived implements kotlin.jvm.internal.KObject, Base {
+public final class Derived implements Base {
     public Derived(@org.jetbrains.annotations.NotNull Base x) { /* compiled code */ }
 
     @org.jetbrains.annotations.NotNull

compiler/testData/asJava/lightClasses/delegation/Property.java

@@ -1,4 +1,4 @@
-public final class Derived implements kotlin.jvm.internal.KObject, Base {
+public final class Derived implements Base {
     public Derived(@org.jetbrains.annotations.NotNull Base x) { /* compiled code */ }
 
     @org.jetbrains.annotations.NotNull

compiler/testData/asJava/lightClasses/delegation/WithPlatformTypes.java

@@ -1,4 +1,4 @@
-public final class WithPlatformTypes implements kotlin.jvm.internal.KObject, p.J {
+public final class WithPlatformTypes implements p.J {
     public WithPlatformTypes(@org.jetbrains.annotations.NotNull p.J j) { /* compiled code */ }
 
     @org.jetbrains.annotations.NotNull

compiler/testData/asJava/lightClasses/nullabilityAnnotations/Class.java

@@ -1,4 +1,4 @@
-public final class Class implements kotlin.jvm.internal.KObject {
+public final class Class {
     @org.jetbrains.annotations.Nullable
     private final java.lang.String nullableVal = "";
     @org.jetbrains.annotations.Nullable

compiler/testData/asJava/lightClasses/nullabilityAnnotations/ClassObjectField.java

@@ -1,4 +1,4 @@
-public final class ClassObjectField implements kotlin.jvm.internal.KObject {
+public final class ClassObjectField {
     @org.jetbrains.annotations.Nullable
     public static final java.lang.String x = "";
     private static final java.lang.String y = "";
@@ -11,7 +11,7 @@ public final class ClassObjectField implements kotlin.jvm.internal.KObject {
 
     public ClassObjectField() { /* compiled code */ }
 
-    public static final class Default implements kotlin.jvm.internal.KObject {
+    public static final class Default {
         @org.jetbrains.annotations.Nullable
         public final java.lang.String getX() { /* compiled code */ }
 

compiler/testData/asJava/lightClasses/nullabilityAnnotations/ClassWithConstructor.java

@@ -1,3 +1,3 @@
-public final class ClassWithConstructor implements kotlin.jvm.internal.KObject {
+public final class ClassWithConstructor {
     public ClassWithConstructor(@org.jetbrains.annotations.Nullable java.lang.String nullable, @org.jetbrains.annotations.NotNull java.lang.String notNull) { /* compiled code */ }
 }

compiler/testData/asJava/lightClasses/nullabilityAnnotations/ClassWithConstructorAndProperties.java

@@ -1,4 +1,4 @@
-public final class ClassWithConstructorAndProperties implements kotlin.jvm.internal.KObject {
+public final class ClassWithConstructorAndProperties {
     @org.jetbrains.annotations.Nullable
     private final java.lang.String nullable;
     @org.jetbrains.annotations.NotNull

compiler/testData/asJava/lightClasses/nullabilityAnnotations/IntOverridesAny.java

@@ -1,4 +1,4 @@
-public final class C implements kotlin.jvm.internal.KObject, Tr {
+public final class C implements Tr {
     private final int v = 1;
 
     @org.jetbrains.annotations.NotNull

compiler/testData/asJava/lightClasses/nullabilityAnnotations/OverrideAnyWithUnit.java

@@ -1,4 +1,4 @@
-public final class C implements kotlin.jvm.internal.KObject, Base {
+public final class C implements Base {
     public void foo() { /* compiled code */ }
 
     public C() { /* compiled code */ }

compiler/testData/asJava/lightClasses/nullabilityAnnotations/PlatformTypes.java

@@ -1,4 +1,4 @@
-public final class PlatformTypes implements kotlin.jvm.internal.KObject {
+public final class PlatformTypes {
     public final java.lang.String simplyPlatform() { /* compiled code */ }
 
     @org.jetbrains.annotations.Nullable

compiler/testData/asJava/lightClasses/nullabilityAnnotations/PrivateInClass.java

@@ -1,4 +1,4 @@
-public final class PrivateInClass implements kotlin.jvm.internal.KObject {
+public final class PrivateInClass {
     private final java.lang.String getNn() { /* compiled code */ }
 
     private final void setNn(java.lang.String value) { /* compiled code */ }

compiler/testData/asJava/lightClasses/nullabilityAnnotations/Synthetic.java

@@ -1,9 +1,9 @@
-public final class Synthetic implements kotlin.jvm.internal.KObject {
+public final class Synthetic {
     private final void foo() { /* compiled code */ }
 
     public Synthetic() { /* compiled code */ }
 
-    public final class Inner implements kotlin.jvm.internal.KObject {
+    public final class Inner {
         public final void test() { /* compiled code */ }
 
         public Inner() { /* compiled code */ }

compiler/testData/asJava/lightClasses/nullabilityAnnotations/TraitClassObjectField.java

@@ -8,7 +8,7 @@ public interface TraitClassObjectField {
     @org.jetbrains.annotations.Nullable
     java.lang.String x = "";
 
-    static final class Default implements kotlin.jvm.internal.KObject {
+    static final class Default {
         @org.jetbrains.annotations.Nullable
         private final java.lang.String x = "";
         private final java.lang.String y = "";

compiler/testData/asJava/lightClasses/nullabilityAnnotations/UnitAsGenericArgument.java

@@ -1,4 +1,4 @@
-public final class C implements kotlin.jvm.internal.KObject, Base<kotlin.Unit> {
+public final class C implements Base<kotlin.Unit> {
     public void foo(@org.jetbrains.annotations.NotNull kotlin.Unit t) { /* compiled code */ }
 
     public C() { /* compiled code */ }

compiler/testData/classpathOrder/classpathOrder.kt

@@ -1,12 +1,12 @@
 package test
 
-import kotlin.jvm.internal.KObject
 import kotlin.jvm.internal.Intrinsics
+import kotlin.jvm.internal.Ref
 
 fun foo(): String {
     // This method call should be resolved to kotlin-runtime.jar
     val r: String = Intrinsics.stringPlus(":", ")")
 
     // This method call should be resolved to sources
-    return KObject.methodWhichDoesNotExistInKotlinRuntime()
+    return Ref.methodWhichDoesNotExistInKotlinRuntime()
 }

compiler/testData/classpathOrder/kotlin/jvm/internal/Ref.java

@@ -1,6 +1,6 @@
 package kotlin.jvm.internal;
 
-public class KObject {
+public class Ref {
     public static String methodWhichDoesNotExistInKotlinRuntime() {
         return ":)";
     }

compiler/testData/codegen/boxWithStdlib/regressions/getGenericInterfaces.kt

@@ -1,7 +1,5 @@
 // KT-4485 getGenericInterfaces vs getInterfaces for kotlin classes
 
-import kotlin.jvm.internal.KObject
-
 class SimpleClass
 
 class ClassWithNonGenericSuperInterface: Cloneable
@@ -10,10 +8,6 @@ class ClassWithGenericSuperInterface: java.util.Comparator<String> {
     override fun compare(a: String, b: String): Int = 0
 }
 
-class ExplicitKObject: java.util.Comparator<String>, KObject {
-    override fun compare(a: String, b: String): Int = 0
-}
-
 fun check(klass: Class<*>) {
     val interfaces = klass.getInterfaces().toList()
     val genericInterfaces = klass.getGenericInterfaces().toList()
@@ -26,6 +20,5 @@ fun box(): String {
     check(javaClass<SimpleClass>())
     check(javaClass<ClassWithNonGenericSuperInterface>())
     check(javaClass<ClassWithGenericSuperInterface>())
-    check(javaClass<ExplicitKObject>())
     return "OK"
 }

compiler/testData/codegen/boxWithStdlib/regressions/kt5609.kt

@@ -1,30 +0,0 @@
-// KT-5609: interfaces should not inherit from KObject, unless explicitly said so
-
-trait A
-
-trait B : kotlin.jvm.internal.KObject
-
-annotation class C
-
-class D
-
-class E : kotlin.jvm.internal.KObject
-
-fun box(): String {
-    val a = javaClass<A>().getGenericInterfaces().toList()
-    if (a.toString() != "[]") return "Fail A: $a"
-
-    val b = javaClass<B>().getGenericInterfaces().toList()
-    if (b.toString() != "[interface kotlin.jvm.internal.KObject]") return "Fail B: $b"
-
-    val c = javaClass<C>().getGenericInterfaces().toList()
-    if (c.toString() != "[interface java.lang.annotation.Annotation]") return "Fail C: $c"
-
-    val d = javaClass<D>().getGenericInterfaces().toList()
-    if (d.toString() != "[interface kotlin.jvm.internal.KObject]") return "Fail D: $d"
-
-    val e = javaClass<E>().getGenericInterfaces().toList()
-    if (e.toString() != "[interface kotlin.jvm.internal.KObject]") return "Fail E: $e"
-
-    return "OK"
-}

compiler/testData/writeSignature/StarProjectionInSuper.kt

@@ -8,4 +8,4 @@ class Sub: Super<C<*>>()
 
 // class: Sub
 // jvm signature:     Sub
-// generic signature: LSuper<LC<*>;>;Lkotlin/jvm/internal/KObject;
+// generic signature: LSuper<LC<*>;>;

compiler/testData/writeSignature/declarationSiteVariance/SuperClassWithVariance.kt

@@ -4,4 +4,4 @@ class Derived<A, B, C>: Base<A, B, C>()
 
 // class: Derived
 // jvm signature:     Derived
-// generic signature: <A:Ljava/lang/Object;B:Ljava/lang/Object;C:Ljava/lang/Object;>LBase<TA;TB;TC;>;Lkotlin/jvm/internal/KObject;
+// generic signature: <A:Ljava/lang/Object;B:Ljava/lang/Object;C:Ljava/lang/Object;>LBase<TA;TB;TC;>;

compiler/testData/writeSignature/declarationSiteVariance/SuperTraitWithVariance.kt

@@ -4,4 +4,4 @@ class Derived<A, B, C>: Base<A, B, C>
 
 // class: Derived
 // jvm signature:     Derived
-// generic signature: <A:Ljava/lang/Object;B:Ljava/lang/Object;C:Ljava/lang/Object;>Ljava/lang/Object;Lkotlin/jvm/internal/KObject;LBase<TA;TB;TC;>;
+// generic signature: <A:Ljava/lang/Object;B:Ljava/lang/Object;C:Ljava/lang/Object;>Ljava/lang/Object;LBase<TA;TB;TC;>;

compiler/testData/writeSignature/declarationSiteVariance/SuperTypeWithVarianceInArguments.kt

@@ -5,4 +5,4 @@ class Derived<A, B, C>: Intermediate<Base<A, B, C>>
 
 // class: Derived
 // jvm signature:     Derived
-// generic signature: <A:Ljava/lang/Object;B:Ljava/lang/Object;C:Ljava/lang/Object;>Ljava/lang/Object;Lkotlin/jvm/internal/KObject;LIntermediate<LBase<TA;-TB;+TC;>;>;
+// generic signature: <A:Ljava/lang/Object;B:Ljava/lang/Object;C:Ljava/lang/Object;>Ljava/lang/Object;LIntermediate<LBase<TA;-TB;+TC;>;>;

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java

@@ -3068,12 +3068,6 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
             doTestWithStdlib(fileName);
         }
 
-        @TestMetadata("kt5609.kt")
-        public void testKt5609() throws Exception {
-            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/regressions/kt5609.kt");
-            doTestWithStdlib(fileName);
-        }
-
         @TestMetadata("kt715.kt")
         public void testKt715() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/regressions/kt715.kt");

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/JvmAbi.java

@@ -17,7 +17,6 @@
 package org.jetbrains.kotlin.load.java;
 
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
 
 public final class JvmAbi {
@@ -40,7 +39,6 @@ public final class JvmAbi {
 
     public static final String INSTANCE_FIELD = "INSTANCE$";
 
-    public static final FqName K_OBJECT = new FqName("kotlin.jvm.internal.KObject");
     public static final String KOTLIN_CLASS_FIELD_NAME = "$kotlinClass";
     public static final String KOTLIN_PACKAGE_FIELD_NAME = "$kotlinPackage";
 

core/runtime.jvm/src/kotlin/jvm/internal/KObject.java

@@ -1,20 +0,0 @@
-/*
- * Copyright 2010-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package kotlin.jvm.internal;
-
-public interface KObject {
-}

idea/src/org/jetbrains/kotlin/idea/debugger/evaluate/KotlinRuntimeTypeEvaluator.kt

@@ -33,12 +33,11 @@ import com.intellij.openapi.project.Project
 import com.intellij.psi.CommonClassNames
 import com.sun.jdi.ClassType
 import com.sun.jdi.Value
-import org.jetbrains.eval4j.jdi.*
+import org.jetbrains.eval4j.jdi.asValue
+import org.jetbrains.kotlin.psi.JetExpression
 import org.jetbrains.kotlin.psi.JetPsiFactory
 import org.jetbrains.kotlin.types.JetType
 import org.jetbrains.org.objectweb.asm.Type as AsmType
-import org.jetbrains.kotlin.psi.JetExpression
-import org.jetbrains.kotlin.load.java.JvmAbi
 
 public abstract class KotlinRuntimeTypeEvaluator(
         editor: Editor?,
@@ -99,8 +98,6 @@ public abstract class KotlinRuntimeTypeEvaluator(
                 }
 
                 for (interfaceType in type.interfaces()) {
-                    if (JvmAbi.K_OBJECT.asString() == interfaceType.name()) continue
-
                     psiClass = AsmType.getType(interfaceType.signature()).getClassDescriptor(project)
                     if (psiClass != null) {
                         return psiClass!!.getDefaultType()

idea/src/org/jetbrains/kotlin/idea/refactoring/javaElementFactoryUtils.kt

@@ -16,18 +16,17 @@
 
 package org.jetbrains.kotlin.idea.refactoring
 
-import com.intellij.psi.PsiReferenceList
-import com.intellij.psi.PsiReferenceList.Role
 import com.intellij.psi.PsiElementFactory
 import com.intellij.psi.PsiJavaCodeReferenceElement
-import org.jetbrains.kotlin.load.java.*
+import com.intellij.psi.PsiReferenceList
+import com.intellij.psi.PsiReferenceList.Role
 
 public fun PsiElementFactory.createReferenceListWithRole(
         references: Array<PsiJavaCodeReferenceElement>,
         role: Role
 ): PsiReferenceList? {
-    val filteredRefs = references.map { it.getCanonicalText() }.filter { it != JvmAbi.K_OBJECT.asString() }
+    val refsText = references.map { it.getCanonicalText() }
-    val refListText = if (filteredRefs.isNotEmpty()) filteredRefs.joinToString() else return null
+    val refListText = if (refsText.isNotEmpty()) refsText.joinToString() else return null
     return when (role) {
         Role.THROWS_LIST -> createMethodFromText("void foo() throws $refListText {}", null).getThrowsList()
         Role.EXTENDS_LIST -> createClassFromText("class Foo extends $refListText {}", null).getInnerClasses()[0].getExtendsList()