Update typing rules for class literal expressions.

C::class : KClass<C>
expr: T => expr::class : KClass<out T>

NB: this means Obj::class : KClass<out Obj> for object Obj.

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DoubleColonExpressionResolver.kt

@@ -92,7 +92,8 @@ class DoubleColonExpressionResolver(
             val type = result?.type
             if (type != null && !type.isError) {
                 checkClassLiteral(c, expression, result)
-                val kClassType = reflectionTypes.getKClassType(Annotations.EMPTY, type)
+                val variance = if (result is DoubleColonLHS.Expression && !result.isObject) Variance.OUT_VARIANCE else Variance.INVARIANT
+                val kClassType = reflectionTypes.getKClassType(Annotations.EMPTY, type, variance)
                 val dataFlowInfo = (result as? DoubleColonLHS.Expression)?.dataFlowInfo ?: c.dataFlowInfo
                 return dataFlowAnalyzer.checkType(createTypeInfo(kClassType, dataFlowInfo), expression, c)
             }

compiler/testData/diagnostics/tests/callableReference/bound/expectedType.kt

@@ -7,6 +7,8 @@ fun test(s: String) {
     val g: () -> String = s::toString
     val h: (Any?) -> Boolean = s::equals
 
-    val k: KClass<String> = s::class
+    val k: KClass<out String> = s::class
     val l: KClass<*> = s::class
+    val m: KClass<String> = String::class
+    val n: KClass<Unit> = Unit::class
 }

compiler/testData/diagnostics/tests/callableReference/bound/reservedExpressionSyntax.txt

@@ -21,9 +21,9 @@ package test {
         public final fun </*0*/ T> kotlin.collections.List<T>.testCallable2(): () -> kotlin.Unit
         public final fun </*0*/ T> kotlin.collections.List<T>.testCallable3(): () -> kotlin.Unit
         public final fun </*0*/ T> kotlin.collections.List<T>.testCallable4(): () -> kotlin.Unit
-        public final fun </*0*/ T> kotlin.collections.List<T>.testClassLiteral1(): kotlin.reflect.KClass<kotlin.Int>
+        public final fun </*0*/ T> kotlin.collections.List<T>.testClassLiteral1(): kotlin.reflect.KClass<out kotlin.Int>
-        public final fun </*0*/ T> kotlin.collections.List<T>.testClassLiteral2(): kotlin.reflect.KClass<kotlin.Int?>
+        public final fun </*0*/ T> kotlin.collections.List<T>.testClassLiteral2(): kotlin.reflect.KClass<out kotlin.Int?>
-        public final fun </*0*/ T> kotlin.collections.List<T>.testClassLiteral3(): kotlin.reflect.KClass<kotlin.Int?>
+        public final fun </*0*/ T> kotlin.collections.List<T>.testClassLiteral3(): kotlin.reflect.KClass<out kotlin.Int?>
         public final fun </*0*/ T> kotlin.collections.List<T>.testUnresolved1(): [ERROR : Error function type]
         public final fun </*0*/ T> kotlin.collections.List<T>.testUnresolved2(): kotlin.reflect.KFunction0<kotlin.Unit>
         public final fun </*0*/ T> kotlin.collections.List<T>.testUnresolved3(): kotlin.reflect.KFunction0<kotlin.Unit>

compiler/testData/diagnostics/tests/callableReference/sam.txt

@@ -8,11 +8,11 @@ public fun f5(): kotlin.reflect.KClass<test.GenericSam<*>>
 public fun f6(): kotlin.reflect.KFunction2<test.GenericSam<*>, @kotlin.ParameterName(name = "t") kotlin.Nothing!, kotlin.Unit>
 public fun f7(): kotlin.reflect.KClass<test.GenericSam<*>>
 public fun f8(): kotlin.reflect.KFunction2<test.GenericSam<kotlin.String>, @kotlin.ParameterName(name = "t") kotlin.String!, kotlin.Unit>
-public fun g1(): kotlin.reflect.KClass<java.lang.Runnable>
+public fun g1(): kotlin.reflect.KClass<out java.lang.Runnable>
 public fun g2(): kotlin.reflect.KFunction0<kotlin.Unit>
-public fun g3(): kotlin.reflect.KClass<java.lang.Runnable>
+public fun g3(): kotlin.reflect.KClass<out java.lang.Runnable>
 public fun g4(): kotlin.reflect.KFunction0<kotlin.Unit>
-public fun g5(): kotlin.reflect.KClass<test.GenericSam<kotlin.String>>
+public fun g5(): kotlin.reflect.KClass<out test.GenericSam<kotlin.String>>
 public fun g6(): kotlin.reflect.KFunction1<@kotlin.ParameterName(name = "t") kotlin.String!, kotlin.Unit>
-public fun g7(): kotlin.reflect.KClass<test.GenericSam<kotlin.String>>
+public fun g7(): kotlin.reflect.KClass<out test.GenericSam<kotlin.String>>
 public fun g8(): kotlin.reflect.KFunction1<@kotlin.ParameterName(name = "t") kotlin.String!, kotlin.Unit>

compiler/testData/diagnostics/tests/classLiteral/classAndObjectLiteralType.kt

@@ -0,0 +1,16 @@
+import kotlin.reflect.KClass
+
+abstract class Base<T : Any>(val klass: KClass<out T>)
+
+class DerivedClass : Base<DerivedClass>(DerivedClass::class)
+
+object DerivedObject : Base<DerivedObject>(DerivedObject::class)
+
+enum class TestEnum {
+    TEST_ENTRY
+}
+
+val test1: KClass<DerivedClass> = DerivedClass::class
+val test2: KClass<DerivedObject> = DerivedObject::class
+val test3: KClass<TestEnum> = TestEnum::class
+val test4: KClass<out TestEnum> = TestEnum.TEST_ENTRY::class

compiler/testData/diagnostics/tests/classLiteral/classAndObjectLiteralType.txt

@@ -0,0 +1,49 @@
+package
+
+public val test1: kotlin.reflect.KClass<DerivedClass>
+public val test2: kotlin.reflect.KClass<DerivedObject>
+public val test3: kotlin.reflect.KClass<TestEnum>
+public val test4: kotlin.reflect.KClass<out TestEnum>
+
+public abstract class Base</*0*/ T : kotlin.Any> {
+    public constructor Base</*0*/ T : kotlin.Any>(/*0*/ klass: kotlin.reflect.KClass<out T>)
+    public final val klass: kotlin.reflect.KClass<out T>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class DerivedClass : Base<DerivedClass> {
+    public constructor DerivedClass()
+    public final override /*1*/ /*fake_override*/ val klass: kotlin.reflect.KClass<out DerivedClass>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public object DerivedObject : Base<DerivedObject> {
+    private constructor DerivedObject()
+    public final override /*1*/ /*fake_override*/ val klass: kotlin.reflect.KClass<out DerivedObject>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final enum class TestEnum : kotlin.Enum<TestEnum> {
+    enum entry TEST_ENTRY
+
+    private constructor TestEnum()
+    public final override /*1*/ /*fake_override*/ val name: kotlin.String
+    public final override /*1*/ /*fake_override*/ val ordinal: kotlin.Int
+    protected final override /*1*/ /*fake_override*/ fun clone(): kotlin.Any
+    public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: TestEnum): kotlin.Int
+    public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    protected/*protected and package*/ final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun finalize(): kotlin.Unit
+    public final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun getDeclaringClass(): java.lang.Class<TestEnum!>!
+    public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): TestEnum
+    public final /*synthesized*/ fun values(): kotlin.Array<TestEnum>
+}

compiler/testData/diagnostics/tests/classLiteral/classLiteralType.kt

@@ -3,7 +3,13 @@ import kotlin.reflect.KClass
 class A
 class B
 
+val listOfString: List<String> = null!!
+val arrayOfString: Array<String> = null!!
+
 val a1 : KClass<*> = A::class
 val a2 : KClass<A> = A::class
 val a3 : KClass<B> = <!TYPE_MISMATCH!>A::class<!>
 val a4 : B = <!TYPE_MISMATCH!>A::class<!>
+
+val a5 : KClass<out List<String>> = listOfString::class
+val a6 : KClass<out Array<String>> = arrayOfString::class

compiler/testData/diagnostics/tests/classLiteral/classLiteralType.txt

@@ -4,6 +4,10 @@ public val a1: kotlin.reflect.KClass<*>
 public val a2: kotlin.reflect.KClass<A>
 public val a3: kotlin.reflect.KClass<B>
 public val a4: B
+public val a5: kotlin.reflect.KClass<out kotlin.collections.List<kotlin.String>>
+public val a6: kotlin.reflect.KClass<out kotlin.Array<kotlin.String>>
+public val arrayOfString: kotlin.Array<kotlin.String>
+public val listOfString: kotlin.collections.List<kotlin.String>
 
 public final class A {
     public constructor A()

compiler/testData/diagnostics/tests/classLiteral/integerValueType.kt

@@ -2,7 +2,7 @@
 
 import kotlin.reflect.KClass
 
-fun f(<!UNUSED_PARAMETER!>x<!>: KClass<Int>) {}
+fun f(<!UNUSED_PARAMETER!>x<!>: KClass<out Int>) {}
 
 fun test() {
     f(42::class)

compiler/testData/diagnostics/tests/classLiteral/integerValueType.txt

@@ -1,4 +1,4 @@
 package
 
-public fun f(/*0*/ x: kotlin.reflect.KClass<kotlin.Int>): kotlin.Unit
+public fun f(/*0*/ x: kotlin.reflect.KClass<out kotlin.Int>): kotlin.Unit
 public fun test(): kotlin.Unit

compiler/testData/diagnostics/tests/sourceCompatibility/noBoundCallableReferences/boundClassLiteral.txt

@@ -1,9 +1,9 @@
 package
 
-public val fail1: kotlin.reflect.KClass<kotlin.String>
+public val fail1: kotlin.reflect.KClass<out kotlin.String>
 public val fail2: kotlin.reflect.KClass<kotlin.String?>
-public val fail3: kotlin.reflect.KClass<C.Companion>
+public val fail3: kotlin.reflect.KClass<out C.Companion>
-public val fail4: kotlin.reflect.KClass<C.Companion>
+public val fail4: kotlin.reflect.KClass<out C.Companion>
 public val ok1: kotlin.reflect.KClass<C>
 public val ok2: kotlin.reflect.KClass<C.Companion>
 public val ok3: kotlin.reflect.KClass<O>

compiler/testData/ir/irText/expressions/classReference.txt

@@ -9,12 +9,12 @@ FILE /classReference.kt
       TYPE_OP origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CLASS_REFERENCE 'A' type=kotlin.reflect.KClass<A>
       TYPE_OP origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-        GET_CLASS type=kotlin.reflect.KClass<A>
+        GET_CLASS type=kotlin.reflect.KClass<out A>
           CALL 'constructor A()' type=A origin=null
       TYPE_OP origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CALL '<get-java>() on KClass<A>: Class<A>' type=java.lang.Class<A> origin=GET_PROPERTY
           $receiver: CLASS_REFERENCE 'A' type=kotlin.reflect.KClass<A>
       TYPE_OP origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-        CALL '<get-java>() on KClass<A>: Class<A>' type=java.lang.Class<A> origin=GET_PROPERTY
+        CALL '<get-java>() on KClass<out A>: Class<out A>' type=java.lang.Class<out A> origin=GET_PROPERTY
-          $receiver: GET_CLASS type=kotlin.reflect.KClass<A>
+          $receiver: GET_CLASS type=kotlin.reflect.KClass<out A>
             CALL 'constructor A()' type=A origin=null

compiler/testData/ir/irText/expressions/reflectionLiterals.txt

@@ -24,15 +24,15 @@ FILE /reflectionLiterals.kt
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='<get-test1>(): KClass<A>'
           GET_FIELD 'test1: KClass<A>' type=kotlin.reflect.KClass<A> origin=null
-  PROPERTY public val test2: kotlin.reflect.KClass<kotlin.Int>
+  PROPERTY public val test2: kotlin.reflect.KClass<out kotlin.Int>
-    FIELD PROPERTY_BACKING_FIELD public val test2: kotlin.reflect.KClass<kotlin.Int>
+    FIELD PROPERTY_BACKING_FIELD public val test2: kotlin.reflect.KClass<out kotlin.Int>
       EXPRESSION_BODY
-        GET_CLASS type=kotlin.reflect.KClass<kotlin.Int>
+        GET_CLASS type=kotlin.reflect.KClass<out kotlin.Int>
           CALL '<get-qux>(): Int' type=kotlin.Int origin=GET_PROPERTY
-    FUN DEFAULT_PROPERTY_ACCESSOR public fun <get-test2>(): kotlin.reflect.KClass<kotlin.Int>
+    FUN DEFAULT_PROPERTY_ACCESSOR public fun <get-test2>(): kotlin.reflect.KClass<out kotlin.Int>
       BLOCK_BODY
-        RETURN type=kotlin.Nothing from='<get-test2>(): KClass<Int>'
+        RETURN type=kotlin.Nothing from='<get-test2>(): KClass<out Int>'
-          GET_FIELD 'test2: KClass<Int>' type=kotlin.reflect.KClass<kotlin.Int> origin=null
+          GET_FIELD 'test2: KClass<out Int>' type=kotlin.reflect.KClass<out kotlin.Int> origin=null
   PROPERTY public val test3: kotlin.reflect.KFunction1<A, kotlin.Unit>
     FIELD PROPERTY_BACKING_FIELD public val test3: kotlin.reflect.KFunction1<A, kotlin.Unit>
       EXPRESSION_BODY

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -2998,6 +2998,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("classAndObjectLiteralType.kt")
+            public void testClassAndObjectLiteralType() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/classLiteral/classAndObjectLiteralType.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("classLiteralType.kt")
             public void testClassLiteralType() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/classLiteral/classLiteralType.kt");

core/descriptors/src/org/jetbrains/kotlin/builtins/ReflectionTypes.kt

@@ -59,13 +59,13 @@ class ReflectionTypes(module: ModuleDescriptor) {
     val kMutableProperty0: ClassDescriptor by ClassLookup
     val kMutableProperty1: ClassDescriptor by ClassLookup
 
-    fun getKClassType(annotations: Annotations, type: KotlinType): KotlinType {
+    fun getKClassType(annotations: Annotations, type: KotlinType, variance: Variance): KotlinType {
         val descriptor = kClass
         if (ErrorUtils.isError(descriptor)) {
             return descriptor.defaultType
         }
 
-        val arguments = listOf(TypeProjectionImpl(Variance.INVARIANT, type))
+        val arguments = listOf(TypeProjectionImpl(variance, type))
         return KotlinTypeFactory.simpleNotNullType(annotations, descriptor, arguments)
     }
 

js/js.translator/testData/box/reflection/kClassIsInstance.kt

@@ -2,7 +2,7 @@ package foo
 
 import kotlin.reflect.KClass
 
-fun <A : Any, B : A> check(k: KClass<A>, instance: B, nonInstance: Any) {
+fun check(k: KClass<*>, instance: Any, nonInstance: Any) {
     assertTrue(k.isInstance(instance))
     assertFalse(k.isInstance(nonInstance))
     assertFalse(k.isInstance(null))