Support nested header/impl classes

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt

@@ -31,7 +31,7 @@ import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.checkers.HeaderImplDeclarationChecker.Compatibility.Compatible
 import org.jetbrains.kotlin.resolve.checkers.HeaderImplDeclarationChecker.Compatibility.Incompatible
-import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+import org.jetbrains.kotlin.resolve.descriptorUtil.classId
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameUnsafe
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
@@ -101,7 +101,7 @@ class HeaderImplDeclarationChecker(val moduleToCheck: ModuleDescriptor? = null)
     private fun checkImplementationHasHeaderDeclaration(
             reportOn: KtDeclaration, descriptor: MemberDescriptor, diagnosticHolder: DiagnosticSink
     ) {
-        fun ClassifierDescriptor.findDeclarationForClass(): ClassDescriptor? =
+        fun ClassifierDescriptorWithTypeParameters.findDeclarationForClass(): ClassDescriptor? =
                 findClassifiersFromTheSameModule().firstOrNull { declaration ->
                     this != declaration &&
                     declaration is ClassDescriptor && declaration.isHeader &&
@@ -122,7 +122,7 @@ class HeaderImplDeclarationChecker(val moduleToCheck: ModuleDescriptor? = null)
                     areCompatibleCallables(declaration, descriptor, checkImpl = false) == Compatible
                 }
             }
-            is ClassifierDescriptor -> descriptor.findDeclarationForClass() != null
+            is ClassifierDescriptorWithTypeParameters -> descriptor.findDeclarationForClass() != null
             else -> false
         }
 
@@ -146,12 +146,26 @@ class HeaderImplDeclarationChecker(val moduleToCheck: ModuleDescriptor? = null)
         }
     }
 
-    fun ClassifierDescriptor.findClassifiersFromTheSameModule(): Collection<ClassifierDescriptor> {
+    fun ClassifierDescriptorWithTypeParameters.findClassifiersFromTheSameModule(): Collection<ClassifierDescriptorWithTypeParameters> {
         val myModule = moduleToCheck ?: module
-        // TODO: support nested classes
-        return myModule.getPackage(fqNameSafe.parent()).memberScope
-                .getDescriptorsFiltered(DescriptorKindFilter.CLASSIFIERS) { it == name }
-                .filterIsInstance<ClassifierDescriptor>()
+        val classId = classId ?: return emptyList()
+
+        fun MemberScope.getAllClassifiers(name: Name): Collection<ClassifierDescriptorWithTypeParameters> =
+                getDescriptorsFiltered(DescriptorKindFilter.CLASSIFIERS) { it == name }
+                        .filterIsInstance<ClassifierDescriptorWithTypeParameters>()
+
+        val segments = classId.relativeClassName.pathSegments()
+        var classifiers = myModule.getPackage(classId.packageFqName).memberScope.getAllClassifiers(segments.first())
+
+        for (name in segments.subList(1, segments.size)) {
+            classifiers = classifiers.mapNotNull { classifier ->
+                (classifier as? ClassDescriptor)?.unsubstitutedInnerClassesScope?.getContributedClassifier(
+                        name, NoLookupLocation.FOR_ALREADY_TRACKED
+                ) as? ClassifierDescriptorWithTypeParameters
+            }
+        }
+
+        return classifiers
     }
 
     sealed class Compatibility {
@@ -190,6 +204,8 @@ class HeaderImplDeclarationChecker(val moduleToCheck: ModuleDescriptor? = null)
 
             object ClassKind : Incompatible("class kinds are different (class, interface, object, enum, annotation)")
 
+            object ClassModifiers : Incompatible("modifiers are different (companion, inner)")
+
             object Supertypes : Incompatible("some supertypes are missing in the implementation")
 
             class ClassScopes(
@@ -318,6 +334,8 @@ class HeaderImplDeclarationChecker(val moduleToCheck: ModuleDescriptor? = null)
 
         if (a.kind != b.kind) return Incompatible.ClassKind
 
+        if (!equalBy(a, b) { listOf(it.isCompanionObject, it.isInner) }) return Incompatible.ClassModifiers
+
         val aTypeParams = a.declaredTypeParameters
         val bTypeParams = b.declaredTypeParameters
         if (aTypeParams.size != bTypeParams.size) return Incompatible.TypeParameterCount

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassMemberScope.kt

@@ -336,6 +336,8 @@ open class LazyClassMemberScope(
         val hasPrimaryConstructor = classOrObject.hasExplicitPrimaryConstructor()
         if (DescriptorUtils.isInterface(thisDescriptor) && !hasPrimaryConstructor) return null
 
+        if (thisDescriptor.isHeader && thisDescriptor.kind == ClassKind.OBJECT) return null
+
         if (DescriptorUtils.canHaveDeclaredConstructors(thisDescriptor) || hasPrimaryConstructor) {
             val constructor = c.functionDescriptorResolver.resolvePrimaryConstructorDescriptor(
                     thisDescriptor.scopeForConstructorHeaderResolution, thisDescriptor, classOrObject, trace)
@@ -343,11 +345,10 @@ open class LazyClassMemberScope(
             setDeferredReturnType(constructor)
             return constructor
         }
-        else {
-            val constructor = DescriptorResolver.createAndRecordPrimaryConstructorForObject(classOrObject, thisDescriptor, trace)
-            setDeferredReturnType(constructor)
-            return constructor
-        }
+
+        val constructor = DescriptorResolver.createAndRecordPrimaryConstructorForObject(classOrObject, thisDescriptor, trace)
+        setDeferredReturnType(constructor)
+        return constructor
     }
 
     private fun resolveSecondaryConstructors(): Collection<ClassConstructorDescriptor> {

compiler/testData/diagnostics/tests/multiplatform/headerClass/classKinds.txt

@@ -40,7 +40,6 @@ public header interface Interface {
 }
 
 public header object Object {
-    private constructor Object()
     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

compiler/testData/diagnostics/tests/multiplatform/headerClass/nestedClasses.kt

@@ -0,0 +1,46 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+
+header class OuterClass {
+    header class NestedClass {
+        header class DeepNested {
+            header class Another
+        }
+    }
+
+    header inner class InnerClass
+
+    header companion object
+}
+
+header class OuterClassWithNamedCompanion {
+    header companion object Factory
+}
+
+header object OuterObject {
+    header object NestedObject
+}
+
+// MODULE: m2-jvm(m1-common)
+// FILE: jvm.kt
+
+impl class OuterClass {
+    impl class NestedClass {
+        impl class DeepNested {
+            impl class Another
+        }
+    }
+
+    impl inner class InnerClass
+
+    impl companion object
+}
+
+impl class OuterClassWithNamedCompanion {
+    impl companion object Factory
+}
+
+impl object OuterObject {
+    impl object NestedObject
+}

compiler/testData/diagnostics/tests/multiplatform/headerClass/nestedClasses.txt

@@ -0,0 +1,142 @@
+// -- Module: <m1-common> --
+package
+
+public final header class OuterClass {
+    public constructor OuterClass()
+    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 header companion object Companion {
+        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 header inner class InnerClass {
+        public constructor InnerClass()
+        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 header class NestedClass {
+        public constructor NestedClass()
+        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 header class DeepNested {
+            public constructor DeepNested()
+            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 header class Another {
+                public constructor Another()
+                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 header class OuterClassWithNamedCompanion {
+    public constructor OuterClassWithNamedCompanion()
+    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 header companion object Factory {
+        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 header object OuterObject {
+    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 header object NestedObject {
+        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
+    }
+}
+
+
+// -- Module: <m2-jvm> --
+package
+
+public final impl class OuterClass {
+    public constructor OuterClass()
+    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 impl companion object Companion {
+        private constructor Companion()
+        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 impl inner class InnerClass {
+        public constructor InnerClass()
+        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 impl class NestedClass {
+        public constructor NestedClass()
+        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 impl class DeepNested {
+            public constructor DeepNested()
+            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 impl class Another {
+                public constructor Another()
+                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 impl class OuterClassWithNamedCompanion {
+    public constructor OuterClassWithNamedCompanion()
+    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 impl companion object Factory {
+        private constructor Factory()
+        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 impl object OuterObject {
+    private constructor OuterObject()
+    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 impl object NestedObject {
+        private constructor NestedObject()
+        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
+    }
+}

compiler/testData/multiplatform/implTypeAlias/generic/output.txt

@@ -5,7 +5,7 @@ Output:
 -- JVM --
 Exit code: OK
 Output:
-compiler/testData/multiplatform/implementClassWithTypeAlias/jvm.kt:3:13: warning: parameter 'a' is never used
+compiler/testData/multiplatform/implTypeAlias/generic/jvm.kt:3:13: warning: parameter 'a' is never used
     fun foo(a: A): List<A>? = null
             ^
 

compiler/testData/multiplatform/implTypeAlias/nestedClassesViaTypeAlias/common.kt

@@ -0,0 +1,3 @@
+header class ByTypeAlias {
+    header interface Nested
+}

compiler/testData/multiplatform/implTypeAlias/nestedClassesViaTypeAlias/jvm.kt

@@ -0,0 +1,5 @@
+class ByTypeAliasImpl {
+    interface Nested
+}
+
+impl typealias ByTypeAlias = ByTypeAliasImpl

compiler/testData/multiplatform/implTypeAlias/nestedClassesViaTypeAlias/output.txt

@@ -0,0 +1,10 @@
+-- Common --
+Exit code: OK
+Output:
+
+-- JVM --
+Exit code: COMPILATION_ERROR
+Output:
+compiler/testData/multiplatform/implTypeAlias/nestedClassesViaTypeAlias/common.kt:2:22: error: header declaration 'Nested' has no implementation in module
+    header interface Nested
+                     ^

compiler/testData/multiplatform/incompatibleNestedClasses/common.kt

@@ -0,0 +1,19 @@
+header class O1 {
+    header class N1
+    header interface N2
+    header object N3
+}
+
+header class O2 {
+    header class N2
+    header inner class I2
+}
+
+header class O3 {
+    header object Companion
+    header companion object Factory
+}
+
+header class O4 {
+    header companion object
+}

compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt

@@ -0,0 +1,19 @@
+impl class O1 {
+    impl interface N1
+    impl object N2
+    impl class N3
+}
+
+impl class O2 {
+    impl inner class N2
+    impl class I2
+}
+
+impl class O3 {
+    impl companion object {}
+    impl object Factory
+}
+
+impl class O4 {
+    impl object Companion
+}

compiler/testData/multiplatform/incompatibleNestedClasses/output.txt

@@ -0,0 +1,80 @@
+-- Common --
+Exit code: OK
+Output:
+
+-- JVM --
+Exit code: COMPILATION_ERROR
+Output:
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:2:18: error: header declaration 'N1' has no implementation in module
+The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
+    public impl interface N1
+
+    header class N1
+                 ^
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:3:22: error: header declaration 'N2' has no implementation in module
+The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
+    public impl object N2
+
+    header interface N2
+                     ^
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:4:12: error: header declaration 'N3' has no implementation in module
+The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
+    public final impl class N3
+
+    header object N3
+           ^
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:8:18: error: header declaration 'N2' has no implementation in module
+The following declaration is incompatible because modifiers are different (companion, inner):
+    public final impl inner class N2
+
+    header class N2
+                 ^
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:9:24: error: header declaration 'I2' has no implementation in module
+The following declaration is incompatible because modifiers are different (companion, inner):
+    public final impl class I2
+
+    header inner class I2
+                       ^
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:13:12: error: header declaration 'Companion' has no implementation in module
+The following declaration is incompatible because modifiers are different (companion, inner):
+    public impl companion object
+
+    header object Companion
+           ^
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:14:22: error: header declaration 'Factory' has no implementation in module
+The following declaration is incompatible because modifiers are different (companion, inner):
+    public impl object Factory
+
+    header companion object Factory
+                     ^
+compiler/testData/multiplatform/incompatibleNestedClasses/common.kt:18:22: error: header declaration 'Companion' has no implementation in module
+The following declaration is incompatible because modifiers are different (companion, inner):
+    public impl object Companion
+
+    header companion object
+                     ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:2:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl interface N1
+    ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:3:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl object N2
+    ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:4:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl class N3
+    ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:8:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl inner class N2
+    ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:9:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl class I2
+    ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:13:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl companion object {}
+    ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:14:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl object Factory
+    ^
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:18:5: error: modifier 'impl' is only applicable to members that are initially declared in platform-independent code
+    impl object Companion
+    ^
+

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

@@ -13104,6 +13104,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("nestedClasses.kt")
+                public void testNestedClasses() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/headerClass/nestedClasses.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("simpleHeaderClass.kt")
                 public void testSimpleHeaderClass() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/headerClass/simpleHeaderClass.kt");

compiler/tests/org/jetbrains/kotlin/multiplatform/MultiPlatformIntegrationTestGenerated.java

@@ -42,12 +42,6 @@ public class MultiPlatformIntegrationTestGenerated extends AbstractMultiPlatform
         doTest(fileName);
     }
 
-    @TestMetadata("implementClassWithTypeAlias")
-    public void testImplementClassWithTypeAlias() throws Exception {
-        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/multiplatform/implementClassWithTypeAlias/");
-        doTest(fileName);
-    }
-
     @TestMetadata("incompatibleCallables")
     public void testIncompatibleCallables() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/multiplatform/incompatibleCallables/");
@@ -66,6 +60,12 @@ public class MultiPlatformIntegrationTestGenerated extends AbstractMultiPlatform
         doTest(fileName);
     }
 
+    @TestMetadata("incompatibleNestedClasses")
+    public void testIncompatibleNestedClasses() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/multiplatform/incompatibleNestedClasses/");
+        doTest(fileName);
+    }
+
     @TestMetadata("incompatibleProperties")
     public void testIncompatibleProperties() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/multiplatform/incompatibleProperties/");
@@ -130,4 +130,26 @@ public class MultiPlatformIntegrationTestGenerated extends AbstractMultiPlatform
 
     }
 
+    @TestMetadata("compiler/testData/multiplatform/implTypeAlias")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class ImplTypeAlias extends AbstractMultiPlatformIntegrationTest {
+        public void testAllFilesPresentInImplTypeAlias() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/multiplatform/implTypeAlias"), Pattern.compile("^([^\\.]+)$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("generic")
+        public void testGeneric() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/multiplatform/implTypeAlias/generic/");
+            doTest(fileName);
+        }
+
+        @TestMetadata("nestedClassesViaTypeAlias")
+        public void testNestedClassesViaTypeAlias() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/multiplatform/implTypeAlias/nestedClassesViaTypeAlias/");
+            doTest(fileName);
+        }
+
+    }
+
 }

core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.kt

@@ -74,11 +74,11 @@ val ClassifierDescriptorWithTypeParameters.denotedClassDescriptor: ClassDescript
         else -> throw UnsupportedOperationException("Unexpected descriptor kind: $this")
     }
 
-val ClassDescriptor.classId: ClassId?
+val ClassifierDescriptorWithTypeParameters.classId: ClassId?
     get() = containingDeclaration.let { owner ->
         when (owner) {
             is PackageFragmentDescriptor -> ClassId(owner.fqName, name)
-            is ClassDescriptor -> owner.classId?.createNestedClassId(name)
+            is ClassifierDescriptorWithTypeParameters -> owner.classId?.createNestedClassId(name)
             else -> null
         }
     }