Report 'nested class accessed via instance reference' error

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java

@@ -591,6 +591,7 @@ public interface Errors {
     DiagnosticFactory1<JetSimpleNameExpression, ClassifierDescriptor> NO_CLASS_OBJECT = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory1<JetSimpleNameExpression, TypeParameterDescriptor> TYPE_PARAMETER_IS_NOT_AN_EXPRESSION = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory1<JetSimpleNameExpression, TypeParameterDescriptor> TYPE_PARAMETER_ON_LHS_OF_DOT = DiagnosticFactory1.create(ERROR);
+    DiagnosticFactory1<JetExpression, ClassDescriptor> NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE = DiagnosticFactory1.create(ERROR);
 
     DiagnosticFactory1<PsiElement, ClassDescriptor> INACCESSIBLE_OUTER_CLASS_EXPRESSION = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory0<PsiElement> NESTED_CLASS_NOT_ALLOWED = DiagnosticFactory0.create(ERROR);

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/DefaultErrorMessages.java

@@ -259,6 +259,7 @@ public class DefaultErrorMessages {
         MAP.put(TYPE_PARAMETER_IS_NOT_AN_EXPRESSION, "Type parameter ''{0}'' is not an expression", NAME);
         MAP.put(TYPE_PARAMETER_ON_LHS_OF_DOT, "Type parameter ''{0}'' cannot have or inherit a class object, so it cannot be on the left hand side of dot", NAME);
         MAP.put(NO_GENERICS_IN_SUPERTYPE_SPECIFIER, "Generic arguments of the base type must be specified");
+        MAP.put(NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE, "Nested {0} accessed via instance reference", RENDER_CLASS_OR_OBJECT_NAME);
 
         MAP.put(INACCESSIBLE_OUTER_CLASS_EXPRESSION, "Expression is inaccessible from a nested class ''{0}'', use ''inner'' keyword to make the class inner", NAME);
         MAP.put(NESTED_CLASS_NOT_ALLOWED, "Nested class is not allowed here, use ''inner'' keyword to make the class inner");

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/DiagnosticRendererUtil.kt

@@ -17,5 +17,29 @@
 package org.jetbrains.jet.lang.diagnostics.rendering
 
 import org.jetbrains.jet.renderer.Renderer
+import org.jetbrains.jet.lang.descriptors.ClassKind
+import org.jetbrains.jet.lang.descriptors.ClassKind.*
+import org.jetbrains.jet.lang.descriptors.ClassDescriptor
+import org.jetbrains.jet.lang.resolve.DescriptorUtils.isClassObject
 
 public fun <P> renderParameter(parameter: P, renderer: Renderer<P>?): Any = renderer?.render(parameter) ?: parameter
+
+public fun ClassDescriptor.renderKindWithName(): String {
+    val kind = getKind().getText()
+    if (isClassObject(this)) {
+        return "$kind of '${getContainingDeclaration().getName()}'"
+    }
+    return "$kind '${getName()}'"
+}
+
+public fun ClassKind.getText(): String {
+    return when (this) {
+        CLASS -> "class"
+        TRAIT -> "trait"
+        ENUM_CLASS -> "enum class"
+        ENUM_ENTRY -> "enum entry"
+        ANNOTATION_CLASS -> "annotation class"
+        OBJECT -> "object"
+        CLASS_OBJECT -> "class object"
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java

@@ -112,7 +112,14 @@ public class Renderers {
                 return "Class" + name;
             }
             return "Object" + name;
+        }
+    };
 
+    public static final Renderer<ClassDescriptor> RENDER_CLASS_OR_OBJECT_NAME = new Renderer<ClassDescriptor>() {
+        @NotNull
+        @Override
+        public String render(@NotNull ClassDescriptor classifier) {
+            return RenderingPackage.renderKindWithName(classifier);
         }
     };
 

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CallExpressionResolver.java

@@ -298,6 +298,7 @@ public class CallExpressionResolver {
         JetType selectorReturnType = selectorReturnTypeInfo.getType();
 
         resolveDeferredReceiverInQualifiedExpression(qualifierReceiver, expression, context);
+        checkNestedClassAccess(expression, context);
 
         //TODO move further
         if (expression.getOperationSign() == JetTokens.SAFE_ACCESS) {
@@ -338,4 +339,24 @@ public class CallExpressionResolver {
                 ? context.trace.get(BindingContext.REFERENCE_TARGET, (JetReferenceExpression) calleeExpression) : null;
         ReceiversPackage.resolveAsReceiverInQualifiedExpression(qualifierReceiver, context, selectorDescriptor);
     }
+
+    private static void checkNestedClassAccess(
+            @NotNull JetQualifiedExpression expression,
+            @NotNull ExpressionTypingContext context
+    ) {
+        JetExpression selectorExpression = expression.getSelectorExpression();
+        if (selectorExpression == null) return;
+
+        // A.B - if B is a nested class accessed by outer class, 'A' and 'A.B' were marked as qualifiers
+        // a.B - if B is a nested class accessed by instance reference, 'a.B' was marked as a qualifier, but 'a' was not (it's an expression)
+
+        QualifierReceiver expressionQualifier = context.trace.get(BindingContext.QUALIFIER_RECEIVER, expression);
+        QualifierReceiver receiverQualifier = context.trace.get(BindingContext.QUALIFIER_RECEIVER, expression.getReceiverExpression());
+
+        if (receiverQualifier == null && expressionQualifier != null) {
+            assert expressionQualifier.getClassifier() instanceof ClassDescriptor :
+                    "Only class can (package cannot) be accessed by instance reference: " + expressionQualifier;
+            context.trace.report(NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE.on(selectorExpression, (ClassDescriptor)expressionQualifier.getClassifier()));
+        }
+    }
 }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java

@@ -38,6 +38,7 @@ import org.jetbrains.jet.lang.resolve.calls.model.*;
 import org.jetbrains.jet.lang.resolve.calls.results.ResolutionStatus;
 import org.jetbrains.jet.lang.resolve.calls.tasks.ResolutionTask;
 import org.jetbrains.jet.lang.resolve.calls.tasks.TaskPrioritizer;
+import org.jetbrains.jet.lang.resolve.calls.util.FakeCallableDescriptorForObject;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
 import org.jetbrains.jet.lang.types.*;
@@ -115,6 +116,9 @@ public class CandidateResolver {
                 }
             }
         }
+        if (!checkThisObject(context)) {
+            candidateCall.addStatus(OTHER_ERROR);
+        }
 
         List<JetTypeProjection> jetTypeArguments = context.call.getTypeArguments();
         if (jetTypeArguments.isEmpty()) {
@@ -167,6 +171,31 @@ public class CandidateResolver {
         }
     }
 
+    private static boolean checkThisObject(@NotNull CallCandidateResolutionContext<?> context) {
+        MutableResolvedCall<? extends CallableDescriptor> candidateCall = context.candidateCall;
+        CallableDescriptor candidateDescriptor = candidateCall.getCandidateDescriptor();
+        ReceiverValue thisObject = candidateCall.getThisObject();
+        if (thisObject.exists()) {
+            ClassDescriptor nestedClass = null;
+            if (candidateDescriptor instanceof ConstructorDescriptor
+                && DescriptorUtils.isStaticNestedClass(candidateDescriptor.getContainingDeclaration())) {
+                nestedClass = (ClassDescriptor) candidateDescriptor.getContainingDeclaration();
+            }
+            else if (candidateDescriptor instanceof FakeCallableDescriptorForObject) {
+                nestedClass = ((FakeCallableDescriptorForObject) candidateDescriptor).getReferencedDescriptor();
+            }
+            if (nestedClass != null) {
+                context.tracing.nestedClassAccessViaInstanceReference(context.trace, nestedClass);
+                return false;
+            }
+        }
+
+        assert (thisObject.exists() == (candidateCall.getResultingDescriptor().getExpectedThisObject() != null))
+                : "Shouldn't happen because of TaskPrioritizer: " + candidateDescriptor;
+
+        return true;
+    }
+
     private static boolean checkOuterClassMemberIsAccessible(@NotNull CallCandidateResolutionContext<?> context) {
         // In "this@Outer.foo()" the error will be reported on "this@Outer" instead
         if (context.call.getExplicitReceiver().exists() || context.call.getThisObject().exists()) return true;

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/ValueArgumentsToParametersMapper.java

@@ -207,9 +207,6 @@ import static org.jetbrains.jet.lang.resolve.calls.ValueArgumentsToParametersMap
             processFunctionLiteralArguments();
             reportUnmappedParameters();
             checkReceiverArgument();
-
-            assert (candidateCall.getThisObject().exists() == (candidateCall.getResultingDescriptor().getExpectedThisObject() != null))
-                    : "Shouldn't happen because of TaskPrioritizer: " + candidateCall.getCandidateDescriptor();
         }
 
         private void processFunctionLiteralArguments() {

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/AbstractTracingStrategy.java

@@ -20,10 +20,7 @@ import com.google.common.collect.Sets;
 import com.intellij.lang.ASTNode;
 import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
-import org.jetbrains.jet.lang.descriptors.DeclarationDescriptorWithVisibility;
-import org.jetbrains.jet.lang.descriptors.ReceiverParameterDescriptor;
-import org.jetbrains.jet.lang.descriptors.ValueParameterDescriptor;
+import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingTrace;
 import org.jetbrains.jet.lang.resolve.calls.inference.*;
@@ -130,6 +127,11 @@ public abstract class AbstractTracingStrategy implements TracingStrategy {
         trace.report(CREATING_AN_INSTANCE_OF_ABSTRACT_CLASS.on(call.getCallElement()));
     }
 
+    @Override
+    public void nestedClassAccessViaInstanceReference(@NotNull BindingTrace trace, @NotNull ClassDescriptor classDescriptor) {
+        trace.report(NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE.on(reference, classDescriptor));
+    }
+
     @Override
     public void unsafeCall(@NotNull BindingTrace trace, @NotNull JetType type, boolean isCallForImplicitInvoke) {
         ASTNode callOperationNode = call.getCallOperationNode();

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/TaskPrioritizer.java

@@ -275,12 +275,6 @@ public class TaskPrioritizer {
             @NotNull Call call
     ) {
         for (D descriptor : descriptors) {
-            if (descriptor instanceof ConstructorDescriptor && DescriptorUtils.isStaticNestedClass(descriptor.getContainingDeclaration())
-                    || descriptor instanceof FakeCallableDescriptorForObject) {
-                // We don't want static nested class constructor or class object / object (as callable)
-                // to be resolved with expectedThisObject
-                continue;
-            }
             ResolutionCandidate<D> candidate = ResolutionCandidate.create(call, descriptor);
             candidate.setThisObject(thisObject);
             candidate.setReceiverArgument(receiverParameter);

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/TracingStrategy.java

@@ -17,10 +17,7 @@
 package org.jetbrains.jet.lang.resolve.calls.tasks;
 
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
-import org.jetbrains.jet.lang.descriptors.DeclarationDescriptorWithVisibility;
-import org.jetbrains.jet.lang.descriptors.ReceiverParameterDescriptor;
-import org.jetbrains.jet.lang.descriptors.ValueParameterDescriptor;
+import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.psi.Call;
 import org.jetbrains.jet.lang.psi.JetFunctionLiteralArgument;
 import org.jetbrains.jet.lang.resolve.BindingTrace;
@@ -83,6 +80,9 @@ public interface TracingStrategy {
         @Override
         public void instantiationOfAbstractClass(@NotNull BindingTrace trace) {}
 
+        @Override
+        public void nestedClassAccessViaInstanceReference(@NotNull BindingTrace trace, @NotNull ClassDescriptor classDescriptor) {}
+
         @Override
         public void unsafeCall(@NotNull BindingTrace trace, @NotNull JetType type, boolean isCallForImplicitInvoke) {}
 
@@ -132,6 +132,8 @@ public interface TracingStrategy {
 
     void instantiationOfAbstractClass(@NotNull BindingTrace trace);
 
+    void nestedClassAccessViaInstanceReference(@NotNull BindingTrace trace, @NotNull ClassDescriptor classDescriptor);
+
     void unsafeCall(@NotNull BindingTrace trace, @NotNull JetType type, boolean isCallForImplicitInvoke);
 
     void unnecessarySafeCall(@NotNull BindingTrace trace, @NotNull JetType type);

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java

@@ -591,16 +591,6 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
             return null;
         }
 
-        ReceiverValue receiver = new TransientReceiver(lhsType);
-        TemporaryTraceAndCache temporaryWithReceiver = TemporaryTraceAndCache.create(
-                context, "trace to resolve callable reference with receiver", reference);
-        CallableDescriptor descriptor = resolveCallableNotCheckingArguments(
-                reference, receiver, context.replaceTraceAndCache(temporaryWithReceiver), result);
-        if (result[0]) {
-            temporaryWithReceiver.commit();
-            return descriptor;
-        }
-
         JetScope staticScope = getStaticNestedClassesScope((ClassDescriptor) classifier);
         TemporaryTraceAndCache temporaryForStatic = TemporaryTraceAndCache.create(
                 context, "trace to resolve callable reference in static scope", reference);
@@ -611,6 +601,16 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
             return possibleStaticNestedClassConstructor;
         }
 
+        ReceiverValue receiver = new TransientReceiver(lhsType);
+        TemporaryTraceAndCache temporaryWithReceiver = TemporaryTraceAndCache.create(
+                context, "trace to resolve callable reference with receiver", reference);
+        CallableDescriptor descriptor = resolveCallableNotCheckingArguments(
+                reference, receiver, context.replaceTraceAndCache(temporaryWithReceiver), result);
+        if (result[0]) {
+            temporaryWithReceiver.commit();
+            return descriptor;
+        }
+
         return null;
     }
 

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/ControlStructureTypingUtils.java

@@ -454,6 +454,13 @@ public class ControlStructureTypingUtils {
             throwError();
         }
 
+        @Override
+        public void nestedClassAccessViaInstanceReference(
+                @NotNull BindingTrace trace, @NotNull ClassDescriptor classDescriptor
+        ) {
+            throwError();
+        }
+
         @Override
         public void unsafeCall(
                 @NotNull BindingTrace trace, @NotNull JetType type, boolean isCallForImplicitInvoke

compiler/testData/codegen/box/objects/kt2398.kt

@@ -13,6 +13,6 @@ class C {
 }
 
 fun box(): String {
-    val res = C().Obj.o + C().Obj.InnerObj.k()  + C().Obj.D().ko
+    val res = C.Obj.o + C.Obj.InnerObj.k()  + C.Obj.D().ko
     return if (res == "OKKO") "OK" else "Fail: $res"
 }

compiler/testData/compileKotlinAgainstKotlin/NestedEnum.B.kt

@@ -1,5 +1,5 @@
 fun main(args: Array<String>) {
-    val str = aaa.A().E.A
+    val str = aaa.A.E.A
     if (str.toString() != "A") {
         throw Exception()
     }

compiler/testData/compileKotlinAgainstKotlin/NestedObject.B.kt

@@ -1,5 +1,5 @@
 fun main(args: Array<String>) {
-    val str = aaa.A().O.s
+    val str = aaa.A.O.s
     if (str != "OK") {
         throw Exception()
     }

compiler/testData/diagnostics/tests/inner/extensionFun.kt

@@ -23,6 +23,6 @@ class Outer {
 
 fun Outer.foo() {
     Outer()
-    <!UNRESOLVED_REFERENCE!>Nested<!>()
+    <!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>Nested<!>()
     Inner()
 }

compiler/testData/diagnostics/tests/inner/nestedClassAccessedViaInstanceReference.kt

@@ -0,0 +1,54 @@
+trait N { fun foo() = 1 }
+
+class WithClassObject {
+    class object {}
+
+    class Nested()
+    class NestedWithClassObject { class object : N }
+    enum class NestedEnum { A }
+    object NestedObj : N { fun invoke() = 1 }
+}
+
+class WithoutClassObject {
+    class Nested()
+    class NestedWithClassObject { class object : N }
+    enum class NestedEnum { A }
+    object NestedObj : N { fun invoke() = 1 }
+}
+
+object Obj {
+    class Nested()
+    class NestedWithClassObject { class object : N }
+    enum class NestedEnum { A }
+    object NestedObj : N { fun invoke() = 1 }
+}
+
+fun test(with: WithClassObject, without: WithoutClassObject, obj: Obj) {
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>Nested<!>()
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>()
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>.foo()
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedEnum<!>.A
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>()
+    with.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>.foo()
+
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>Nested<!>()
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>()
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>.foo()
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedEnum<!>.A
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>()
+    without.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>.foo()
+
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>Nested<!>()
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>()
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedWithClassObject<!>.foo()
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedEnum<!>.A
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>()
+    obj.<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>NestedObj<!>.foo()
+}
+

compiler/testData/diagnostics/tests/objects/invokeOnInnerObject.kt

@@ -0,0 +1,12 @@
+//no nested class access via instance reference error
+fun test() {
+    A.f(<!TYPE_MISMATCH!>""<!>)
+}
+
+class A() {
+    class object {
+        object f {
+            fun invoke(i: Int) = i
+        }
+    }
+}

compiler/testData/diagnostics/testsWithStdLib/callableReference/function/nestedConstructorFromExtension.kt

@@ -6,7 +6,7 @@ class A {
 }
     
 fun A.main() {
-    ::<!UNRESOLVED_REFERENCE!>Nested<!>
+    ::<!NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE!>Nested<!>
     val y = A::Nested
     
     y : KFunction0<A.Nested>

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -4944,6 +4944,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest("compiler/testData/diagnostics/tests/inner/modality.kt");
             }
             
+            @TestMetadata("nestedClassAccessedViaInstanceReference.kt")
+            public void testNestedClassAccessedViaInstanceReference() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/inner/nestedClassAccessedViaInstanceReference.kt");
+            }
+            
             @TestMetadata("nestedClassExtendsOuter.kt")
             public void testNestedClassExtendsOuter() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/inner/nestedClassExtendsOuter.kt");
@@ -5896,6 +5901,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/tests/objects"), Pattern.compile("^(.+)\\.kt$"), true);
             }
             
+            @TestMetadata("invokeOnInnerObject.kt")
+            public void testInvokeOnInnerObject() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/objects/invokeOnInnerObject.kt");
+            }
+            
             @TestMetadata("kt2240.kt")
             public void testKt2240() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/objects/kt2240.kt");

idea/testData/checker/regression/createInnerInstance.kt

@@ -6,5 +6,5 @@ object A {
 
 fun test<T>(a: T) {
   val c = (a as A)
-  c.<error descr="[FUNCTION_EXPECTED] Expression 'B' of type '[Package-type B]' cannot be invoked as a function. The function invoke() is not found"><error>B</error></error>()
+    c.<error descr="[NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE] Nested class 'B' accessed via instance reference">B</error>()
 }

idea/testData/diagnosticMessage/nestedClassAcessedViaInstanceReference.kt

@@ -0,0 +1,16 @@
+// !DIAGNOSTICS_NUMBER: 4
+// !DIAGNOSTICS: NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE
+
+class A {
+    class Nested()
+    class NestedWithClassObject { class object }
+    enum class NestedEnum { A }
+    object NestedObj { fun invoke() = 1 }
+}
+
+fun test(a: A) {
+    a.Nested()
+    a.NestedWithClassObject
+    a.NestedEnum
+    a.NestedObj
+}

idea/testData/diagnosticMessage/nestedClassAcessedViaInstanceReference1.txt

@@ -0,0 +1,2 @@
+<!-- nestedClassAcessedViaInstanceReference1 -->
+Nested class 'Nested' accessed via instance reference

idea/testData/diagnosticMessage/nestedClassAcessedViaInstanceReference2.txt

@@ -0,0 +1,2 @@
+<!-- nestedClassAcessedViaInstanceReference2 -->
+Nested class object of 'NestedWithClassObject' accessed via instance reference

idea/testData/diagnosticMessage/nestedClassAcessedViaInstanceReference3.txt

@@ -0,0 +1,2 @@
+<!-- nestedClassAcessedViaInstanceReference3 -->
+Nested enum class 'NestedEnum' accessed via instance reference

idea/testData/diagnosticMessage/nestedClassAcessedViaInstanceReference4.txt

@@ -0,0 +1,2 @@
+<!-- nestedClassAcessedViaInstanceReference4 -->
+Nested object 'NestedObj' accessed via instance reference

idea/tests/org/jetbrains/jet/plugin/highlighter/DiagnosticMessageTestGenerated.java

@@ -98,6 +98,11 @@ public class DiagnosticMessageTestGenerated extends AbstractDiagnosticMessageTes
         doTest("idea/testData/diagnosticMessage/nameInConstraintIsNotATypeParameter.kt");
     }
     
+    @TestMetadata("nestedClassAcessedViaInstanceReference.kt")
+    public void testNestedClassAcessedViaInstanceReference() throws Exception {
+        doTest("idea/testData/diagnosticMessage/nestedClassAcessedViaInstanceReference.kt");
+    }
+    
     @TestMetadata("noneApplicable.kt")
     public void testNoneApplicable() throws Exception {
         doTest("idea/testData/diagnosticMessage/noneApplicable.kt");

js/js.translator/testData/enum/cases/accessing.kt

@@ -5,32 +5,25 @@ enum class A {
 
     BAR : A() {
         fun explicitFromEntry() = A.FOO
-        //fun byThisFromEntry() = this.FOO
         fun implicitFromEntry() = FOO
     }
 
     fun explicit() = A.FOO
-    fun byThis() = this.FOO
     fun implicit() = FOO
 }
 
 fun A.extExplicit() = A.FOO
-fun A.extByThis() = this.FOO
 //fun A.extImplicit() = FOO
 
 fun box(): String {
     assertEquals(A.FOO, A.FOO.explicit(), "explicit access")
-    assertEquals(A.FOO, A.FOO.byThis(), "access by this")
     assertEquals(A.FOO, A.FOO.implicit(), "implicit access")
 
     assertEquals(A.FOO, A.FOO.explicit(), "explicit access from BAR")
-    // TODO uncoment when KT-4692 will be fixed
-    //assertEquals(A.FOO, A.FOO.byThis(), "access by this from BAR")
     assertEquals(A.FOO, A.FOO.implicit(), "implicit access from BAR")
 
     assertEquals(A.FOO, A.FOO.extExplicit(), "explicit access from ext fun")
-    assertEquals(A.FOO, A.FOO.extByThis(), "access by this from ext fun")
-    // TODO uncoment when KT-4692 will be fixed
+    // TODO uncoment when KT-5605 will be fixed
     //assertEquals(A.FOO, A.FOO.extImplicit(), "implicit access from ext fun")
 
     return "OK"