[FIR] Allow actualization of expect classes by classes with wider visibility

^KT-59355 Fixed

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated.java

@@ -175,6 +175,12 @@ public class FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated extends Abst
         runTest("compiler/testData/diagnostics/tests/multiplatform/varSetterVisibility.kt");
     }
 
+    @Test
+    @TestMetadata("widerVisibilityInActualClassifier.kt")
+    public void testWiderVisibilityInActualClassifier() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/widerVisibilityInActualClassifier.kt");
+    }
+
     @Nested
     @TestMetadata("compiler/testData/diagnostics/tests/multiplatform/defaultArguments")
     @TestDataPath("$PROJECT_ROOT")

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithPsiTestGenerated.java

@@ -175,6 +175,12 @@ public class FirOldFrontendMPPDiagnosticsWithPsiTestGenerated extends AbstractFi
         runTest("compiler/testData/diagnostics/tests/multiplatform/varSetterVisibility.kt");
     }
 
+    @Test
+    @TestMetadata("widerVisibilityInActualClassifier.kt")
+    public void testWiderVisibilityInActualClassifier() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/widerVisibilityInActualClassifier.kt");
+    }
+
     @Nested
     @TestMetadata("compiler/testData/diagnostics/tests/multiplatform/defaultArguments")
     @TestDataPath("$PROJECT_ROOT")

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java

@@ -33632,6 +33632,12 @@ public class FirLightTreeBlackBoxCodegenTestGenerated extends AbstractFirLightTr
                 public void testValueClasses() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/valueClasses.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java

@@ -33632,6 +33632,12 @@ public class FirPsiBlackBoxCodegenTestGenerated extends AbstractFirPsiBlackBoxCo
                 public void testValueClasses() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/valueClasses.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/mpp/FirExpectActualMatchingContext.kt

@@ -40,6 +40,9 @@ class FirExpectActualMatchingContext(
     override val enumConstructorsAreAlwaysCompatible: Boolean
         get() = true
 
+    override val allowClassActualizationWithWiderVisibility: Boolean
+        get() = true
+
     private fun CallableSymbolMarker.asSymbol(): FirCallableSymbol<*> = this as FirCallableSymbol<*>
     private fun FunctionSymbolMarker.asSymbol(): FirFunctionSymbol<*> = this as FirFunctionSymbol<*>
     private fun PropertySymbolMarker.asSymbol(): FirPropertySymbol = this as FirPropertySymbol

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/actualizer/IrExpectActualMatchingContext.kt

@@ -33,6 +33,9 @@ internal abstract class IrExpectActualMatchingContext(
     val typeContext: IrTypeSystemContext,
     val expectToActualClassMap: Map<ClassId, IrClassSymbol>
 ) : ExpectActualMatchingContext<IrSymbol>, TypeSystemContext by typeContext {
+    override val allowClassActualizationWithWiderVisibility: Boolean
+        get() = true
+
     private inline fun <R> CallableSymbolMarker.processIr(
         onFunction: (IrFunction) -> R,
         onProperty: (IrProperty) -> R,

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/mpp/AbstractExpectActualCompatibilityChecker.kt

@@ -106,7 +106,7 @@ object AbstractExpectActualCompatibilityChecker {
             return Incompatible.Modality
         }
 
-        if (expectClassSymbol.visibility != actualClass.visibility) {
+        if (!areCompatibleClassVisibilities(expectClassSymbol, actualClass)) {
             return Incompatible.Visibility
         }
 
@@ -330,7 +330,7 @@ object AbstractExpectActualCompatibilityChecker {
             return Incompatible.Modality
         }
 
-        if (!areDeclarationsWithCompatibleVisibilities(expectDeclaration.visibility, expectModality, actualDeclaration.visibility)) {
+        if (!areCompatibleCallableVisibilities(expectDeclaration.visibility, expectModality, actualDeclaration.visibility)) {
             return Incompatible.Visibility
         }
 
@@ -436,7 +436,7 @@ object AbstractExpectActualCompatibilityChecker {
         Modality.SEALED to enumSetOf(Modality.SEALED),
     )
 
-    private fun areDeclarationsWithCompatibleVisibilities(
+    private fun areCompatibleCallableVisibilities(
         expectVisibility: Visibility,
         expectModality: Modality?,
         actualVisibility: Visibility,
@@ -451,6 +451,19 @@ object AbstractExpectActualCompatibilityChecker {
         }
     }
 
+    context(ExpectActualMatchingContext<*>)
+    private fun areCompatibleClassVisibilities(
+        expectClassSymbol: RegularClassSymbolMarker,
+        actualClassSymbol: RegularClassSymbolMarker,
+    ): Boolean {
+        val expectVisibility = expectClassSymbol.visibility
+        val actualVisibility = actualClassSymbol.visibility
+        if (expectVisibility == actualVisibility) return true
+        if (!allowClassActualizationWithWiderVisibility) return false
+        val result = Visibilities.compare(actualVisibility, expectVisibility)
+        return result != null && result > 0
+    }
+
     context(ExpectActualMatchingContext<*>)
     private fun areCompatibleTypeParameters(
         expectTypeParameterSymbols: List<TypeParameterSymbolMarker>,
@@ -525,7 +538,7 @@ object AbstractExpectActualCompatibilityChecker {
     ): Boolean {
         val expectedSetter = expected.setter ?: return true
         val actualSetter = actual.setter ?: return true
-        return areDeclarationsWithCompatibleVisibilities(expectedSetter.visibility, expectedSetter.modality, actualSetter.visibility)
+        return areCompatibleCallableVisibilities(expectedSetter.visibility, expectedSetter.modality, actualSetter.visibility)
     }
 
     // ---------------------------------------- Utils ----------------------------------------

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/mpp/ExpectActualMatchingContext.kt

@@ -39,6 +39,17 @@ interface ExpectActualMatchingContext<T : DeclarationSymbolMarker> : TypeSystemC
     val enumConstructorsAreAlwaysCompatible: Boolean
         get() = false
 
+    /**
+     * This flag determines, how visibilities for classes/typealiases will be matched
+     * - `false` means that visibilities should be identical
+     * - `true` means that visibility of actual class should be the same or wider comparing to expect visibility
+     *     this means that following actualizations will be additionally allowed:
+     *     - protected -> public
+     *     - internal -> public
+     */
+    val allowClassActualizationWithWiderVisibility: Boolean
+        get() = false
+
     val RegularClassSymbolMarker.classId: ClassId
     val TypeAliasSymbolMarker.classId: ClassId
     val CallableSymbolMarker.callableId: CallableId

compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt

@@ -0,0 +1,49 @@
+// IGNORE_BACKEND_K1: ANY
+//   IGNORE_REASON: KT-59355 is fixed only in K2
+// IGNORE_BACKEND_K2: JS_IR
+//   IGNORE_REASON: `JsName` in js.translator/testData/_commonFiles/testUtils.kt is invisible for some reason
+// IGNORE_BACKEND: WASM
+//   IGNORE_REASON: wasm tests don't support IGNORE_BACKEND_K1 directive
+// LANGUAGE: +MultiPlatformProjects
+// ISSUE: KT-59355
+
+// MODULE: common
+// FILE: common.kt
+internal expect open class Some() {
+    protected class ProtectedNested() {
+        fun foo(): String
+    }
+}
+
+internal class SomeInheritor : Some() {
+    fun callFoo(): String {
+        return ProtectedNested().foo()
+    }
+}
+
+internal expect open class Other() {
+    fun bar(): String
+}
+
+fun commonBox(): String {
+    val x = SomeInheritor().callFoo()
+    val y = Other().bar()
+    return x + y
+}
+
+// MODULE: platform-jvm()()(common)
+// FILE: main.kt
+public actual open class Some actual constructor() {
+    public actual class ProtectedNested actual constructor() {
+        actual fun foo(): String = "O"
+    }
+}
+
+public open class PlatformOther {
+    fun bar(): String = "K"
+}
+
+internal actual typealias Other = PlatformOther
+
+fun box(): String = commonBox()
+

compiler/testData/diagnostics/tests/multiplatform/widerVisibilityInActualClassifier.fir.kt

@@ -0,0 +1,34 @@
+// ISSUE: KT-59355
+
+// MODULE: common
+internal expect open class Some {
+    protected class ProtectedNested
+    internal class InternalNested
+
+    public fun publicFun()
+    internal fun internalFun()
+    protected fun protectedFun()
+}
+
+internal expect open class Other {
+    protected class ProtectedNested
+    internal class InternalNested
+}
+
+// MODULE: platform-jvm()()(common)
+public actual open class Some { // should be allowed
+    public class ProtectedNested  // should be allowed
+    public class InternalNested // should be allowed
+
+    public actual fun publicFun() {} // should be allowed
+    public actual fun internalFun() {} // should be allowed
+    public actual fun protectedFun() {} // should be allowed
+}
+
+public open class PlatformOther { // should be allowed
+    public class ProtectedNested  // should be allowed
+    public class InternalNested // should be allowed
+}
+
+internal actual typealias Other = PlatformOther // should be allowed
+

compiler/testData/diagnostics/tests/multiplatform/widerVisibilityInActualClassifier.kt

@@ -0,0 +1,34 @@
+// ISSUE: KT-59355
+
+// MODULE: common
+internal expect open class <!NO_ACTUAL_FOR_EXPECT!>Some<!> {
+    protected class ProtectedNested
+    internal class InternalNested
+
+    public fun publicFun()
+    internal fun internalFun()
+    protected fun protectedFun()
+}
+
+internal expect open class <!NO_ACTUAL_FOR_EXPECT!>Other<!> {
+    protected class ProtectedNested
+    internal class InternalNested
+}
+
+// MODULE: platform-jvm()()(common)
+<!ACTUAL_WITHOUT_EXPECT!>public<!> actual open class Some { // should be allowed
+    <!ACTUAL_WITHOUT_EXPECT!>public<!> class <!ACTUAL_MISSING!>ProtectedNested<!>  // should be allowed
+    <!ACTUAL_WITHOUT_EXPECT!>public<!> class <!ACTUAL_MISSING!>InternalNested<!> // should be allowed
+
+    public actual fun publicFun() {} // should be allowed
+    public actual fun internalFun() {} // should be allowed
+    public actual fun protectedFun() {} // should be allowed
+}
+
+public open class PlatformOther { // should be allowed
+    public class ProtectedNested  // should be allowed
+    public class InternalNested // should be allowed
+}
+
+<!ACTUAL_WITHOUT_EXPECT!>internal<!> actual typealias Other = PlatformOther // should be allowed
+

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -22486,6 +22486,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/multiplatform/varSetterVisibility.kt");
             }
 
+            @Test
+            @TestMetadata("widerVisibilityInActualClassifier.kt")
+            public void testWiderVisibilityInActualClassifier() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/widerVisibilityInActualClassifier.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/diagnostics/tests/multiplatform/defaultArguments")
             @TestDataPath("$PROJECT_ROOT")

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -32072,6 +32072,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -33632,6 +33632,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 public void testValueClasses() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/valueClasses.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java

@@ -33632,6 +33632,12 @@ public class IrBlackBoxCodegenWithIrInlinerTestGenerated extends AbstractIrBlack
                 public void testValueClasses() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/valueClasses.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

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

@@ -27349,6 +27349,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 public void testNonExternalEquals() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/nonExternalEquals.kt");
                 }
+
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/defaultArguments")

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

@@ -23432,6 +23432,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsCodegenBoxTestGenerated.java

@@ -23594,6 +23594,12 @@ public class FirJsCodegenBoxTestGenerated extends AbstractFirJsCodegenBoxTest {
                 public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

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

@@ -23594,6 +23594,12 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
                 public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsES6CodegenBoxTestGenerated.java

@@ -23594,6 +23594,12 @@ public class IrJsES6CodegenBoxTestGenerated extends AbstractIrJsES6CodegenBoxTes
                 public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                 }
+
+                @Test
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/FirNativeCodegenBoxTestGenerated.java

@@ -26666,6 +26666,12 @@ public class FirNativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTe
                     public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                         runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                     }
+
+                    @Test
+                    @TestMetadata("widerVisibilityInActualClassifier.kt")
+                    public void testWiderVisibilityInActualClassifier() throws Exception {
+                        runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                    }
                 }
 
                 @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/FirNativeCodegenBoxTestNoPLGenerated.java

@@ -27272,6 +27272,12 @@ public class FirNativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenB
                     public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                         runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                     }
+
+                    @Test
+                    @TestMetadata("widerVisibilityInActualClassifier.kt")
+                    public void testWiderVisibilityInActualClassifier() throws Exception {
+                        runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                    }
                 }
 
                 @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeCodegenBoxTestGenerated.java

@@ -26364,6 +26364,12 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
                     public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                         runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                     }
+
+                    @Test
+                    @TestMetadata("widerVisibilityInActualClassifier.kt")
+                    public void testWiderVisibilityInActualClassifier() throws Exception {
+                        runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                    }
                 }
 
                 @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeCodegenBoxTestNoPLGenerated.java

@@ -26667,6 +26667,12 @@ public class NativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenBoxT
                     public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                         runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                     }
+
+                    @Test
+                    @TestMetadata("widerVisibilityInActualClassifier.kt")
+                    public void testWiderVisibilityInActualClassifier() throws Exception {
+                        runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                    }
                 }
 
                 @Nested

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

@@ -20962,6 +20962,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
                 public void testRemoveExpectDeclarationsFromMetadata() throws Exception {
                     runTest("compiler/testData/codegen/box/multiplatform/k2/basic/removeExpectDeclarationsFromMetadata.kt");
                 }
+
+                @TestMetadata("widerVisibilityInActualClassifier.kt")
+                public void testWiderVisibilityInActualClassifier() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/basic/widerVisibilityInActualClassifier.kt");
+                }
             }
 
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/defaultArguments")