[FE] Allow declare sealed class inheritors in different files in one module

#KT-13495

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/fir/FirOldFrontendDiagnosticsTestGenerated.java

@@ -20778,6 +20778,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
             runTest("compiler/testData/diagnostics/tests/sealed/LocalSealed.kt");
         }
 
+        @TestMetadata("MultipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/sealed/MultipleFiles_enabled.kt");
+        }
+
         @TestMetadata("NestedSealed.kt")
         public void testNestedSealed() throws Exception {
             runTest("compiler/testData/diagnostics/tests/sealed/NestedSealed.kt");

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -30255,6 +30255,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");

compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt

@@ -323,7 +323,8 @@ class FunctionDescriptorResolver(
         scope: LexicalScope,
         classDescriptor: ClassDescriptor,
         classElement: KtPureClassOrObject,
-        trace: BindingTrace
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
     ): ClassConstructorDescriptorImpl? {
         if (classDescriptor.kind == ClassKind.ENUM_ENTRY || !classElement.hasPrimaryConstructor()) return null
         return createConstructorDescriptor(
@@ -333,7 +334,8 @@ class FunctionDescriptorResolver(
             classElement.primaryConstructorModifierList,
             classElement.primaryConstructor ?: classElement,
             classElement.primaryConstructorParameters,
-            trace
+            trace,
+            languageVersionSettings
         )
     }
 
@@ -341,7 +343,8 @@ class FunctionDescriptorResolver(
         scope: LexicalScope,
         classDescriptor: ClassDescriptor,
         constructor: KtSecondaryConstructor,
-        trace: BindingTrace
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
     ): ClassConstructorDescriptorImpl {
         return createConstructorDescriptor(
             scope,
@@ -350,7 +353,8 @@ class FunctionDescriptorResolver(
             constructor.modifierList,
             constructor,
             constructor.valueParameters,
-            trace
+            trace,
+            languageVersionSettings
         )
     }
 
@@ -361,7 +365,8 @@ class FunctionDescriptorResolver(
         modifierList: KtModifierList?,
         declarationToTrace: KtPureElement,
         valueParameters: List<KtParameter>,
-        trace: BindingTrace
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
     ): ClassConstructorDescriptorImpl {
         val constructorDescriptor = ClassConstructorDescriptorImpl.create(
             classDescriptor,
@@ -387,7 +392,7 @@ class FunctionDescriptorResolver(
             resolveValueParameters(constructorDescriptor, parameterScope, valueParameters, trace, null),
             resolveVisibilityFromModifiers(
                 modifierList,
-                DescriptorUtils.getDefaultConstructorVisibility(classDescriptor)
+                DescriptorUtils.getDefaultConstructorVisibility(classDescriptor, languageVersionSettings.supportsFeature(LanguageFeature.FreedomForSealedClasses))
             )
         )
         constructor.returnType = classDescriptor.defaultType

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

@@ -488,7 +488,7 @@ open class LazyClassMemberScope(
 
         if (DescriptorUtils.canHaveDeclaredConstructors(thisDescriptor) || hasPrimaryConstructor) {
             val constructor = c.functionDescriptorResolver.resolvePrimaryConstructorDescriptor(
-                thisDescriptor.scopeForConstructorHeaderResolution, thisDescriptor, classOrObject, trace
+                thisDescriptor.scopeForConstructorHeaderResolution, thisDescriptor, classOrObject, trace, c.languageVersionSettings
             )
             constructor ?: return null
             setDeferredReturnType(constructor)
@@ -505,7 +505,7 @@ open class LazyClassMemberScope(
 
         return classOrObject.secondaryConstructors.map { constructor ->
             val descriptor = c.functionDescriptorResolver.resolveSecondaryConstructorDescriptor(
-                thisDescriptor.scopeForConstructorHeaderResolution, thisDescriptor, constructor, trace
+                thisDescriptor.scopeForConstructorHeaderResolution, thisDescriptor, constructor, trace, c.languageVersionSettings
             )
             setDeferredReturnType(descriptor)
             descriptor

compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt

@@ -0,0 +1,24 @@
+// ISSUE: KT-13495
+// IGNORE_BACKEND_FIR: JVM_IR
+// !LANGUAGE: +FreedomForSealedClasses
+
+// FILE: a.kt
+
+sealed class Base {
+    class A : Base()
+}
+
+// FILE: b.kt
+
+class B : Base()
+
+// FILE: c.kt
+
+fun getLetter(base: Base): String = when (base) {
+    is Base.A -> "O"
+    is B -> "K"
+}
+
+fun box(): String {
+    return getLetter(Base.A()) + getLetter(B())
+}

compiler/testData/diagnostics/tests/sealed/MultipleFiles_enabled.fir.kt

@@ -0,0 +1,30 @@
+// ISSUE: KT-13495
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+// !LANGUAGE: +FreedomForSealedClasses
+
+// FILE: a.kt
+
+sealed class Base {
+    class A : Base()
+}
+
+// FILE: b.kt
+
+class B : <!HIDDEN!>Base<!>()
+
+// FILE: c.kt
+
+class Container {
+    class C : <!HIDDEN, SEALED_SUPERTYPE!>Base<!>()
+
+    inner class D : <!HIDDEN, SEALED_SUPERTYPE!>Base<!>()
+}
+
+// FILE: d.kt
+
+fun test(base: Base) {
+    val x = when (base) {
+        is Base.A -> 1
+        is B -> 2
+    }
+}

compiler/testData/diagnostics/tests/sealed/MultipleFiles_enabled.kt

@@ -0,0 +1,30 @@
+// ISSUE: KT-13495
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+// !LANGUAGE: +FreedomForSealedClasses
+
+// FILE: a.kt
+
+sealed class Base {
+    class A : Base()
+}
+
+// FILE: b.kt
+
+class B : Base()
+
+// FILE: c.kt
+
+class Container {
+    class C : <!SEALED_SUPERTYPE!>Base<!>()
+
+    inner class D : <!SEALED_SUPERTYPE!>Base<!>()
+}
+
+// FILE: d.kt
+
+fun test(base: Base) {
+    val x = when (base) {
+        is Base.A -> 1
+        is B -> 2
+    }
+}

compiler/testData/diagnostics/tests/sealed/MultipleFiles_enabled.txt

@@ -0,0 +1,45 @@
+package
+
+public fun test(/*0*/ base: Base): kotlin.Unit
+
+public final class B : Base {
+    public constructor B()
+    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 sealed class Base {
+    internal constructor Base()
+    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 A : Base {
+        public constructor A()
+        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 Container {
+    public constructor Container()
+    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 C : Base {
+        public constructor C()
+        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 inner class D : Base {
+        public constructor D()
+        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/tests-gen/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -20855,6 +20855,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTestWithFirVali
                 runTest("compiler/testData/diagnostics/tests/sealed/LocalSealed.kt");
             }
 
+            @TestMetadata("MultipleFiles_enabled.kt")
+            public void testMultipleFiles_enabled() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/sealed/MultipleFiles_enabled.kt");
+            }
+
             @TestMetadata("NestedSealed.kt")
             public void testNestedSealed() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/sealed/NestedSealed.kt");

compiler/tests-gen/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -20780,6 +20780,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/sealed/LocalSealed.kt");
             }
 
+            @TestMetadata("MultipleFiles_enabled.kt")
+            public void testMultipleFiles_enabled() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/sealed/MultipleFiles_enabled.kt");
+            }
+
             @TestMetadata("NestedSealed.kt")
             public void testNestedSealed() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/sealed/NestedSealed.kt");

compiler/tests-gen/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -32026,6 +32026,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -29660,6 +29660,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");

compiler/tests-gen/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -30255,6 +30255,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");

compiler/util/src/org/jetbrains/kotlin/config/LanguageVersionSettings.kt

@@ -143,6 +143,8 @@ enum class LanguageFeature(
     UseCorrectExecutionOrderForVarargArguments(KOTLIN_1_5, kind = BUG_FIX),
     JvmRecordSupport(KOTLIN_1_5),
 
+    FreedomForSealedClasses(KOTLIN_1_5),
+
     // Temporarily disabled, see KT-27084/KT-22379
     SoundSmartcastFromLoopConditionForLoopAssignedVariables(sinceVersion = null, kind = BUG_FIX),
 

core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorFactory.java

@@ -35,10 +35,14 @@ import static org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt.getB
 
 public class DescriptorFactory {
     private static class DefaultClassConstructorDescriptor extends ClassConstructorDescriptorImpl {
-        public DefaultClassConstructorDescriptor(@NotNull ClassDescriptor containingClass, @NotNull SourceElement source) {
+        public DefaultClassConstructorDescriptor(
+                @NotNull ClassDescriptor containingClass,
+                @NotNull SourceElement source,
+                boolean freedomForSealedInterfacesSupported
+        ) {
             super(containingClass, null, Annotations.Companion.getEMPTY(), true, Kind.DECLARATION, source);
             initialize(Collections.<ValueParameterDescriptor>emptyList(),
-                       getDefaultConstructorVisibility(containingClass));
+                       getDefaultConstructorVisibility(containingClass, freedomForSealedInterfacesSupported));
         }
     }
 
@@ -130,7 +134,11 @@ public class DescriptorFactory {
             @NotNull ClassDescriptor containingClass,
             @NotNull SourceElement source
     ) {
-        return new DefaultClassConstructorDescriptor(containingClass, source);
+        /*
+         * Language version settings are needed here only for computing default visibility of constructors of sealed classes
+         *   Since object can not be sealed class it's OK to pass default settings here
+         */
+        return new DefaultClassConstructorDescriptor(containingClass, source, false);
     }
 
     @NotNull

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

@@ -380,11 +380,21 @@ public class DescriptorUtils {
     }
 
     @NotNull
-    public static DescriptorVisibility getDefaultConstructorVisibility(@NotNull ClassDescriptor classDescriptor) {
+    public static DescriptorVisibility getDefaultConstructorVisibility(
+            @NotNull ClassDescriptor classDescriptor,
+            boolean freedomForSealedInterfacesSupported
+    ) {
         ClassKind classKind = classDescriptor.getKind();
-        if (classKind == ClassKind.ENUM_CLASS || classKind.isSingleton() || isSealedClass(classDescriptor)) {
+        if (classKind == ClassKind.ENUM_CLASS || classKind.isSingleton()) {
             return DescriptorVisibilities.PRIVATE;
         }
+        if (isSealedClass(classDescriptor)) {
+            if (freedomForSealedInterfacesSupported) {
+                return DescriptorVisibilities.INTERNAL;
+            } else {
+                return DescriptorVisibilities.PRIVATE;
+            }
+        }
         if (isAnonymousObject(classDescriptor)) {
             return DescriptorVisibilities.DEFAULT_VISIBILITY;
         }

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/es6/semantics/IrJsCodegenBoxES6TestGenerated.java

@@ -24526,6 +24526,11 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR_ES6, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -24526,6 +24526,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -24526,6 +24526,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/wasm/semantics/IrCodegenBoxWasmTestGenerated.java

@@ -12997,6 +12997,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sealed"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
         }
 
+        @TestMetadata("multipleFiles_enabled.kt")
+        public void testMultipleFiles_enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sealed/multipleFiles_enabled.kt");
+        }
+
         @TestMetadata("objects.kt")
         public void testObjects() throws Exception {
             runTest("compiler/testData/codegen/box/sealed/objects.kt");