Allow open callable members in expect interfaces

#KT-42094 fixed

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

@@ -14556,6 +14556,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
             runTest("compiler/testData/diagnostics/tests/modifiers/NoLocalVisibility.kt");
         }
 
+        @TestMetadata("openInExpectInterface.kt")
+        public void testOpenInExpectInterface() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/modifiers/openInExpectInterface.kt");
+        }
+
         @TestMetadata("openInInterface.kt")
         public void testOpenInInterface() throws Exception {
             runTest("compiler/testData/diagnostics/tests/modifiers/openInInterface.kt");
@@ -15015,6 +15020,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
         }
 
+        @TestMetadata("expectInterfaceApplicability.kt")
+        public void testExpectInterfaceApplicability() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/multiplatform/expectInterfaceApplicability.kt");
+        }
+
         @TestMetadata("headerFunInNonHeaderClass.kt")
         public void testHeaderFunInNonHeaderClass() throws Exception {
             runTest("compiler/testData/diagnostics/tests/multiplatform/headerFunInNonHeaderClass.kt");

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

@@ -772,7 +772,7 @@ class DeclarationsChecker(
                 if (function.hasModifier(KtTokens.PRIVATE_KEYWORD)) {
                     trace.report(PRIVATE_FUNCTION_WITH_NO_BODY.on(function, functionDescriptor))
                 }
-                if (!hasAbstractModifier && function.hasModifier(KtTokens.OPEN_KEYWORD)) {
+                if (!containingDescriptor.isExpect && !hasAbstractModifier && function.hasModifier(KtTokens.OPEN_KEYWORD)) {
                     trace.report(REDUNDANT_OPEN_IN_INTERFACE.on(function))
                 }
             }

compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.java

@@ -80,7 +80,7 @@ public class ModifiersChecker {
             boolean allowSealed
     ) {
         KtModifierList modifierList = (modifierListOwner != null) ? modifierListOwner.getModifierList() : null;
-        Modality modality = resolveModalityFromModifiers(modifierList, defaultModality, allowSealed);
+        Modality modality = resolveModalityFromModifiers(containingDescriptor, modifierList, defaultModality, allowSealed);
 
         if (modifierListOwner != null) {
             Collection<DeclarationAttributeAltererExtension> extensions =
@@ -103,6 +103,7 @@ public class ModifiersChecker {
 
     @NotNull
     private static Modality resolveModalityFromModifiers(
+            @Nullable DeclarationDescriptor containingDescriptor,
             @Nullable KtModifierList modifierList,
             @NotNull Modality defaultModality,
             boolean allowSealed
@@ -115,6 +116,12 @@ public class ModifiersChecker {
             return Modality.SEALED;
         }
         if (modifierList.hasModifier(OPEN_KEYWORD)) {
+            if (containingDescriptor instanceof ClassDescriptor) {
+                ClassDescriptor classOrInterface = (ClassDescriptor) containingDescriptor;
+                if (classOrInterface.getKind() == ClassKind.INTERFACE && classOrInterface.isExpect()) {
+                    return Modality.OPEN;
+                }
+            }
             if (hasAbstractModifier || defaultModality == Modality.ABSTRACT) {
                 return Modality.ABSTRACT;
             }
@@ -141,7 +148,10 @@ public class ModifiersChecker {
         return resolveVisibilityFromModifiers(modifierListOwner.getModifierList(), defaultVisibility);
     }
 
-    public static DescriptorVisibility resolveVisibilityFromModifiers(@Nullable KtModifierList modifierList, @NotNull DescriptorVisibility defaultVisibility) {
+    public static DescriptorVisibility resolveVisibilityFromModifiers(
+            @Nullable KtModifierList modifierList,
+            @NotNull DescriptorVisibility defaultVisibility
+    ) {
         if (modifierList == null) return defaultVisibility;
         if (modifierList.hasModifier(PRIVATE_KEYWORD)) return DescriptorVisibilities.PRIVATE;
         if (modifierList.hasModifier(PUBLIC_KEYWORD)) return DescriptorVisibilities.PUBLIC;
@@ -226,7 +236,7 @@ public class ModifiersChecker {
         public void checkModifiersForDestructuringDeclaration(@NotNull KtDestructuringDeclaration multiDeclaration) {
             annotationChecker.check(multiDeclaration, trace, null);
             ModifierCheckerCore.INSTANCE.check(multiDeclaration, trace, null, languageVersionSettings);
-            for (KtDestructuringDeclarationEntry multiEntry: multiDeclaration.getEntries()) {
+            for (KtDestructuringDeclarationEntry multiEntry : multiDeclaration.getEntries()) {
                 annotationChecker.check(multiEntry, trace, null);
                 ModifierCheckerCore.INSTANCE.check(multiEntry, trace, null, languageVersionSettings);
                 UnderscoreChecker.INSTANCE.checkNamed(multiEntry, trace, languageVersionSettings, /* allowSingleUnderscore = */ true);

compiler/testData/diagnostics/tests/modifiers/openInExpectInterface.fir.kt

@@ -0,0 +1,37 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+// TODO: .fir.kt version is just a stub.
+
+expect interface My {
+    open fun bar()
+    open fun bas() {}
+    <!REDUNDANT_MODIFIER!>open<!> abstract fun bat(): Int
+
+    fun foo()
+
+
+    open val a: Int
+    open val b: String
+    open val c: String get() = ""
+    <!REDUNDANT_MODIFIER!>open<!> abstract val e: Int
+
+    val f: Int
+}
+
+class MyImpl1: My
+
+class MyImpl2: My {
+    override fun foo() {}
+    override val f = 0
+    override val e = 1
+}
+
+expect interface Outer {
+    interface Inner {
+        open fun bar()
+        open fun bas() {}
+        <!REDUNDANT_MODIFIER!>open<!> abstract fun bat(): Int
+        fun foo()
+    }
+}

compiler/testData/diagnostics/tests/modifiers/openInExpectInterface.kt

@@ -0,0 +1,37 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+// TODO: .fir.kt version is just a stub.
+
+expect interface My {
+    open fun bar()
+    <!EXPECTED_DECLARATION_WITH_BODY!>open fun bas()<!> {}
+    <!REDUNDANT_MODIFIER!>open<!> abstract fun bat(): Int
+
+    fun foo()
+
+
+    open val a: Int
+    open val b: String
+    open val c: String <!EXPECTED_DECLARATION_WITH_BODY!>get()<!> = ""
+    <!REDUNDANT_MODIFIER!>open<!> abstract val e: Int
+
+    val f: Int
+}
+
+<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyImpl1<!>: My
+
+class MyImpl2: My {
+    override fun foo() {}
+    override val f = 0
+    override val e = 1
+}
+
+expect interface Outer {
+    interface Inner {
+        open fun bar()
+        <!EXPECTED_DECLARATION_WITH_BODY!>open fun bas()<!> {}
+        <!REDUNDANT_MODIFIER!>open<!> abstract fun bat(): Int
+        fun foo()
+    }
+}

compiler/testData/diagnostics/tests/modifiers/openInExpectInterface.txt

@@ -0,0 +1,64 @@
+package
+
+public expect interface My {
+    public expect open val a: kotlin.Int
+    public expect open val b: kotlin.String
+    public expect open val c: kotlin.String
+    public expect open val e: kotlin.Int
+    public expect abstract val f: kotlin.Int
+    public open expect fun bar(): kotlin.Unit
+    public open expect fun bas(): kotlin.Unit
+    public open expect fun bat(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract expect fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class MyImpl1 : My {
+    public constructor MyImpl1()
+    public expect open override /*1*/ /*fake_override*/ val a: kotlin.Int
+    public expect open override /*1*/ /*fake_override*/ val b: kotlin.String
+    public expect open override /*1*/ /*fake_override*/ val c: kotlin.String
+    public expect open override /*1*/ /*fake_override*/ val e: kotlin.Int
+    public expect abstract override /*1*/ /*fake_override*/ val f: kotlin.Int
+    public open expect override /*1*/ /*fake_override*/ fun bar(): kotlin.Unit
+    public open expect override /*1*/ /*fake_override*/ fun bas(): kotlin.Unit
+    public open expect override /*1*/ /*fake_override*/ fun bat(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract expect override /*1*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class MyImpl2 : My {
+    public constructor MyImpl2()
+    public expect open override /*1*/ /*fake_override*/ val a: kotlin.Int
+    public expect open override /*1*/ /*fake_override*/ val b: kotlin.String
+    public expect open override /*1*/ /*fake_override*/ val c: kotlin.String
+    public open override /*1*/ val e: kotlin.Int = 1
+    public open override /*1*/ val f: kotlin.Int = 0
+    public open expect override /*1*/ /*fake_override*/ fun bar(): kotlin.Unit
+    public open expect override /*1*/ /*fake_override*/ fun bas(): kotlin.Unit
+    public open expect override /*1*/ /*fake_override*/ fun bat(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public expect interface Outer {
+    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 expect interface Inner {
+        public open expect fun bar(): kotlin.Unit
+        public open expect fun bas(): kotlin.Unit
+        public open expect fun bat(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public abstract expect fun foo(): kotlin.Unit
+        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/expectInterfaceApplicability.fir.kt

@@ -0,0 +1,25 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+// TODO: .fir.kt version is just a stub.
+expect interface My {
+    open fun openFunPositive()
+    open fun openFunNegative()
+    abstract fun abstractFun()
+
+    open val openValPositive: Int
+    open val openValNegative: Int
+    abstract val abstractVal: Int
+}
+
+// MODULE: m1-jvm(m1-common)
+// FILE: jvm.kt
+actual interface My {
+    actual fun openFunPositive() = Unit
+    actual fun openFunNegative()
+    actual fun abstractFun()
+
+    actual val openValPositive: Int get() = 0
+    actual val openValNegative: Int
+    actual val abstractVal: Int
+}

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

@@ -0,0 +1,25 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+// TODO: .fir.kt version is just a stub.
+expect interface My {
+    open fun openFunPositive()
+    open fun openFunNegative()
+    abstract fun abstractFun()
+
+    open val openValPositive: Int
+    open val openValNegative: Int
+    abstract val abstractVal: Int
+}
+
+// MODULE: m1-jvm(m1-common)
+// FILE: jvm.kt
+actual interface My {
+    actual fun openFunPositive() = Unit
+    actual fun <!ACTUAL_WITHOUT_EXPECT!>openFunNegative<!>()
+    actual fun abstractFun()
+
+    actual val openValPositive: Int get() = 0
+    actual val <!ACTUAL_WITHOUT_EXPECT!>openValNegative<!>: Int
+    actual val abstractVal: Int
+}

compiler/testData/diagnostics/tests/multiplatform/expectInterfaceApplicability.txt

@@ -0,0 +1,30 @@
+// -- Module: <m1-common> --
+package
+
+public expect interface My {
+    public expect abstract val abstractVal: kotlin.Int
+    public expect open val openValNegative: kotlin.Int
+    public expect open val openValPositive: kotlin.Int
+    public abstract expect fun abstractFun(): kotlin.Unit
+    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 expect fun openFunNegative(): kotlin.Unit
+    public open expect fun openFunPositive(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+
+// -- Module: <m1-jvm> --
+package
+
+public actual interface My {
+    public actual abstract val abstractVal: kotlin.Int
+    public actual abstract val openValNegative: kotlin.Int
+    public actual open val openValPositive: kotlin.Int
+    public abstract actual fun abstractFun(): kotlin.Unit
+    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 abstract actual fun openFunNegative(): kotlin.Unit
+    public open actual fun openFunPositive(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

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

@@ -14563,6 +14563,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTestWithFirVali
                 runTest("compiler/testData/diagnostics/tests/modifiers/NoLocalVisibility.kt");
             }
 
+            @TestMetadata("openInExpectInterface.kt")
+            public void testOpenInExpectInterface() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/modifiers/openInExpectInterface.kt");
+            }
+
             @TestMetadata("openInInterface.kt")
             public void testOpenInInterface() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/modifiers/openInInterface.kt");
@@ -15022,6 +15027,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTestWithFirVali
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform"), Pattern.compile("^(.*)\\.kts?$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
             }
 
+            @TestMetadata("expectInterfaceApplicability.kt")
+            public void testExpectInterfaceApplicability() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/expectInterfaceApplicability.kt");
+            }
+
             @TestMetadata("headerFunInNonHeaderClass.kt")
             public void testHeaderFunInNonHeaderClass() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/multiplatform/headerFunInNonHeaderClass.kt");

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

@@ -14558,6 +14558,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/modifiers/NoLocalVisibility.kt");
             }
 
+            @TestMetadata("openInExpectInterface.kt")
+            public void testOpenInExpectInterface() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/modifiers/openInExpectInterface.kt");
+            }
+
             @TestMetadata("openInInterface.kt")
             public void testOpenInInterface() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/modifiers/openInInterface.kt");
@@ -15017,6 +15022,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
             }
 
+            @TestMetadata("expectInterfaceApplicability.kt")
+            public void testExpectInterfaceApplicability() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/expectInterfaceApplicability.kt");
+            }
+
             @TestMetadata("headerFunInNonHeaderClass.kt")
             public void testHeaderFunInNonHeaderClass() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/multiplatform/headerFunInNonHeaderClass.kt");

idea/tests/org/jetbrains/kotlin/idea/caches/resolve/MultiplatformAnalysisTestGenerated.java

@@ -208,7 +208,7 @@ public class MultiplatformAnalysisTestGenerated extends AbstractMultiplatformAna
         runTest("idea/testData/multiplatform/simple/");
     }
 
-    @TestMetadata("simple")
+    @TestMetadata("smartCastOnPropertyFromDependentModule")
     public void testSmartCastOnPropertyFromDependentModule() throws Exception {
         runTest("idea/testData/multiplatform/smartCastOnPropertyFromDependentModule/");
     }

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/CirFunctionOrProperty.kt

@@ -23,9 +23,6 @@ interface CirFunctionOrProperty :
     val returnType: CirType
     val kind: CallableMemberDescriptor.Kind
 
-    fun isNonAbstractMemberInInterface(): Boolean =
-        modality != Modality.ABSTRACT && containingClassDetails?.kind == ClassKind.INTERFACE
-
     fun isVirtual(): Boolean =
         visibility != DescriptorVisibilities.PRIVATE
                 && modality != Modality.FINAL

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/AbstractFunctionOrPropertyCommonizer.kt

@@ -29,8 +29,7 @@ abstract class AbstractFunctionOrPropertyCommonizer<T : CirFunctionOrProperty>(
     }
 
     override fun doCommonizeWith(next: T): Boolean =
-        !next.isNonAbstractMemberInInterface() // non-abstract callable members declared in interface can't be commonized
+        next.kind != DELEGATION // delegated members should not be commonized
-                && next.kind != DELEGATION // delegated members should not be commonized
                 && (next.kind != SYNTHESIZED || next.containingClassDetails?.isData != true) // synthesized members of data classes should not be commonized
                 && kind == next.kind
                 && modality.commonizeWith(next.modality)

native/commonizer/testData/callableMemberCommonization/openCallableMemberInInterface/commonized/common/package_root.kt

@@ -0,0 +1,3 @@
+expect interface Interface {
+    open fun openFun()
+}

native/commonizer/testData/callableMemberCommonization/openCallableMemberInInterface/commonized/js/package_root.kt

@@ -0,0 +1,5 @@
+actual interface Interface {
+    actual fun openFun() = Unit
+    fun openFunWithOtherParams(param: Int) = Unit
+    fun openInJs_abstractInJvm() = Unit
+}

native/commonizer/testData/callableMemberCommonization/openCallableMemberInInterface/commonized/jvm/package_root.kt

@@ -0,0 +1,5 @@
+actual interface Interface {
+    actual fun openFun() = Unit
+    fun openFunWithOtherParams(param: Double) = Unit
+    fun openInJs_abstractInJvm()
+}

native/commonizer/testData/callableMemberCommonization/openCallableMemberInInterface/original/js/package_root.kt

@@ -0,0 +1,5 @@
+interface Interface {
+    fun openFun() = Unit
+    fun openFunWithOtherParams(param: Int) = Unit
+    fun openInJs_abstractInJvm() = Unit
+}

native/commonizer/testData/callableMemberCommonization/openCallableMemberInInterface/original/jvm/package_root.kt

@@ -0,0 +1,5 @@
+interface Interface {
+    fun openFun() = Unit
+    fun openFunWithOtherParams(param: Double) = Unit
+    fun openInJs_abstractInJvm()
+}

native/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/CallableMemberCommonizationFromSourcesTest.kt

@@ -15,4 +15,6 @@ class CallableMemberCommonizationFromSourcesTest : AbstractCommonizationFromSour
     fun testReturnTypes() = doTestSuccessfulCommonization()
 
     fun testExtensionReceivers() = doTestSuccessfulCommonization()
+
+    fun testOpenCallableMemberInInterface() = doTestSuccessfulCommonization()
 }