[FIR] Introduce FirDeclarationStatus.hasStableParameterNames

This flag is true by default but is set to false for

- Java methods and constructors
- interface delegation methods that delegate to Java

The NAMED_ARGUMENTS_NOT_ALLOWED logic is mostly refactored to use the
new flag though some custom logic remains for determining the correct
message and to work around a corner case with fake overrides.

The flag is (de)serialized from/to metadata. For backward compatibility
with K1, delegated methods to Java types are deserialized as stable.

^KT-40480 Fixed

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/KtFirAnonymousFunctionSymbol.kt

@@ -21,7 +21,7 @@ import org.jetbrains.kotlin.analysis.api.symbols.pointers.CanNotCreateSymbolPoin
 import org.jetbrains.kotlin.analysis.api.symbols.pointers.KtPsiBasedSymbolPointer
 import org.jetbrains.kotlin.analysis.api.symbols.pointers.KtSymbolPointer
 import org.jetbrains.kotlin.analysis.api.types.KtType
-import org.jetbrains.kotlin.fir.resolve.getHasStableParameterNames
+import org.jetbrains.kotlin.fir.declarations.utils.hasStableParameterNames
 import org.jetbrains.kotlin.fir.symbols.impl.FirAnonymousFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.isExtension
 
@@ -46,7 +46,7 @@ internal class KtFirAnonymousFunctionSymbol(
 
     override val hasStableParameterNames: Boolean
         get() = withValidityAssertion {
-            firSymbol.fir.getHasStableParameterNames(firSymbol.moduleData.session)
+            firSymbol.fir.hasStableParameterNames
         }
     override val isExtension: Boolean get() = withValidityAssertion { firSymbol.isExtension }
 

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/KtFirConstructorSymbol.kt

@@ -24,8 +24,8 @@ import org.jetbrains.kotlin.analysis.api.symbols.pointers.KtSymbolPointer
 import org.jetbrains.kotlin.analysis.api.types.KtType
 import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.fir.containingClassLookupTag
+import org.jetbrains.kotlin.fir.declarations.utils.hasStableParameterNames
 import org.jetbrains.kotlin.fir.declarations.utils.visibility
-import org.jetbrains.kotlin.fir.resolve.getHasStableParameterNames
 import org.jetbrains.kotlin.fir.symbols.impl.FirConstructorSymbol
 import org.jetbrains.kotlin.name.ClassId
 
@@ -41,7 +41,7 @@ internal class KtFirConstructorSymbol(
 
     override val hasStableParameterNames: Boolean
         get() = withValidityAssertion {
-            firSymbol.fir.getHasStableParameterNames(firSymbol.moduleData.session)
+            firSymbol.fir.hasStableParameterNames
         }
 
     override val visibility: Visibility get() = withValidityAssertion { firSymbol.visibility }

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/KtFirFunctionSymbol.kt

@@ -34,7 +34,6 @@ import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.fir.containingClassLookupTag
 import org.jetbrains.kotlin.fir.contracts.FirEffectDeclaration
 import org.jetbrains.kotlin.fir.declarations.utils.*
-import org.jetbrains.kotlin.fir.resolve.getHasStableParameterNames
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.isExtension
 import org.jetbrains.kotlin.name.CallableId
@@ -65,7 +64,7 @@ internal class KtFirFunctionSymbol(
     override val valueParameters: List<KtValueParameterSymbol> by cached { firSymbol.createKtValueParameters(builder) }
 
     override val hasStableParameterNames: Boolean
-        get() = withValidityAssertion { firSymbol.fir.getHasStableParameterNames(firSymbol.moduleData.session) }
+        get() = withValidityAssertion { firSymbol.fir.hasStableParameterNames }
 
     override val annotationsList by cached {
         KtFirAnnotationListForDeclaration.create(

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/KtFirSamConstructorSymbol.kt

@@ -22,7 +22,7 @@ import org.jetbrains.kotlin.analysis.api.symbols.KtTypeParameterSymbol
 import org.jetbrains.kotlin.analysis.api.symbols.KtValueParameterSymbol
 import org.jetbrains.kotlin.analysis.api.symbols.pointers.KtSymbolPointer
 import org.jetbrains.kotlin.analysis.api.types.KtType
-import org.jetbrains.kotlin.fir.resolve.getHasStableParameterNames
+import org.jetbrains.kotlin.fir.declarations.utils.hasStableParameterNames
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.isExtension
 import org.jetbrains.kotlin.name.CallableId
@@ -54,7 +54,7 @@ internal class KtFirSamConstructorSymbol(
 
     override val hasStableParameterNames: Boolean
         get() = withValidityAssertion {
-            firSymbol.fir.getHasStableParameterNames(firSymbol.moduleData.session)
+            firSymbol.fir.hasStableParameterNames
         }
 
     override val isExtension: Boolean get() = withValidityAssertion { firSymbol.isExtension }

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -22094,6 +22094,18 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/namedArguments/ambiguousNamedArgumentsWithGenerics3.kt");
             }
 
+            @Test
+            @TestMetadata("disallowForDelegationToJavaMethods.kt")
+            public void testDisallowForDelegationToJavaMethods() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForDelegationToJavaMethods.kt");
+            }
+
+            @Test
+            @TestMetadata("disallowForFunctionTypes.kt")
+            public void testDisallowForFunctionTypes() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForFunctionTypes.kt");
+            }
+
             @Test
             @TestMetadata("disallowForJavaConstructor.kt")
             public void testDisallowForJavaConstructor() throws Exception {

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

@@ -22100,6 +22100,18 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/namedArguments/ambiguousNamedArgumentsWithGenerics3.kt");
             }
 
+            @Test
+            @TestMetadata("disallowForDelegationToJavaMethods.kt")
+            public void testDisallowForDelegationToJavaMethods() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForDelegationToJavaMethods.kt");
+            }
+
+            @Test
+            @TestMetadata("disallowForFunctionTypes.kt")
+            public void testDisallowForFunctionTypes() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForFunctionTypes.kt");
+            }
+
             @Test
             @TestMetadata("disallowForJavaConstructor.kt")
             public void testDisallowForJavaConstructor() throws Exception {

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

@@ -22094,6 +22094,18 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/tests/namedArguments/ambiguousNamedArgumentsWithGenerics3.kt");
             }
 
+            @Test
+            @TestMetadata("disallowForDelegationToJavaMethods.kt")
+            public void testDisallowForDelegationToJavaMethods() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForDelegationToJavaMethods.kt");
+            }
+
+            @Test
+            @TestMetadata("disallowForFunctionTypes.kt")
+            public void testDisallowForFunctionTypes() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForFunctionTypes.kt");
+            }
+
             @Test
             @TestMetadata("disallowForJavaConstructor.kt")
             public void testDisallowForJavaConstructor() throws Exception {

compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirMemberDeserializer.kt

@@ -502,6 +502,7 @@ class FirMemberDeserializer(private val c: FirDeserializationContext) {
                 isTailRec = Flags.IS_TAILREC.get(flags)
                 isExternal = Flags.IS_EXTERNAL_FUNCTION.get(flags)
                 isSuspend = Flags.IS_SUSPEND.get(flags)
+                hasStableParameterNames = !Flags.IS_FUNCTION_WITH_NON_STABLE_PARAMETER_NAMES.get(flags)
             }
             this.symbol = symbol
             dispatchReceiverType = c.dispatchReceiver
@@ -571,6 +572,7 @@ class FirMemberDeserializer(private val c: FirDeserializationContext) {
                 visibility.toEffectiveVisibility(classBuilder.symbol)
             ).apply {
                 isExpect = Flags.IS_EXPECT_FUNCTION.get(flags)
+                hasStableParameterNames = !Flags.IS_CONSTRUCTOR_WITH_NON_STABLE_PARAMETER_NAMES.get(flags)
                 isActual = false
                 isOverride = false
                 this.isInner = isInner

compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt

@@ -433,8 +433,9 @@ class FirElementSerializer private constructor(
             simpleFunction?.isExternal == true,
             simpleFunction?.isSuspend == true,
             simpleFunction?.isExpect == true,
-            true // TODO: supply 'hasStableParameterNames' flag for metadata
+            shouldSetStableParameterNames(simpleFunction),
         )
+
         if (flags != builder.flags) {
             builder.flags = flags
         }
@@ -507,6 +508,15 @@ class FirElementSerializer private constructor(
         return builder
     }
 
+    private fun shouldSetStableParameterNames(simpleFunction: FirSimpleFunction?): Boolean {
+        return when {
+            simpleFunction?.hasStableParameterNames == true -> true
+            // for backward compatibility with K1, remove this line to fix KT-4758
+            simpleFunction?.origin == FirDeclarationOrigin.Delegated -> true
+            else -> false
+        }
+    }
+
     private fun typeAliasProto(typeAlias: FirTypeAlias): ProtoBuf.TypeAlias.Builder? = whileAnalysing(session, typeAlias) {
         if (!extension.shouldSerializeTypeAlias(typeAlias)) return null
 
@@ -570,7 +580,7 @@ class FirElementSerializer private constructor(
             constructor.nonSourceAnnotations(session).isNotEmpty(),
             ProtoEnumFlags.visibility(normalizeVisibility(constructor)),
             !constructor.isPrimary,
-            true // TODO: supply 'hasStableParameterNames' flag for metadata
+            constructor.hasStableParameterNames,
         )
         if (flags != builder.flags) {
             builder.flags = flags

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/FirJavaFacade.kt

@@ -572,6 +572,7 @@ abstract class FirJavaFacade(
                 // Approximation: all Java methods with name that allows to use it in operator form are considered operators
                 // We need here more detailed checks (see modifierChecks.kt)
                 isOperator = name in ALL_JAVA_OPERATION_NAMES || OperatorNameConventions.COMPONENT_REGEX.matches(name.asString())
+                hasStableParameterNames = false
             }
 
             if (!javaMethod.isStatic) {
@@ -628,6 +629,7 @@ abstract class FirJavaFacade(
                 visibility.toEffectiveVisibility(ownerClassBuilder.symbol)
             ).apply {
                 isInner = isThisInner
+                hasStableParameterNames = false
             }
             this.visibility = visibility
             isPrimary = javaConstructor == null

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/SignatureEnhancement.kt

@@ -21,10 +21,7 @@ import org.jetbrains.kotlin.fir.declarations.impl.FirDeclarationStatusImpl
 import org.jetbrains.kotlin.fir.declarations.impl.FirResolvedDeclarationStatusImpl
 import org.jetbrains.kotlin.fir.declarations.synthetic.FirSyntheticProperty
 import org.jetbrains.kotlin.fir.declarations.synthetic.buildSyntheticProperty
-import org.jetbrains.kotlin.fir.declarations.utils.isInner
+import org.jetbrains.kotlin.fir.declarations.utils.*
-import org.jetbrains.kotlin.fir.declarations.utils.isStatic
-import org.jetbrains.kotlin.fir.declarations.utils.modality
-import org.jetbrains.kotlin.fir.declarations.utils.visibility
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
 import org.jetbrains.kotlin.fir.expressions.FirConstExpression
 import org.jetbrains.kotlin.fir.expressions.unexpandedClassId
@@ -262,6 +259,8 @@ class FirSignatureEnhancement(
                             FirDeclarationStatusImpl(firMethod.visibility, Modality.FINAL)
                         }.apply {
                             isInner = firMethod.isInner
+                            // Java annotation class constructors have stable names, copy flag.
+                            hasStableParameterNames = firMethod.hasStableParameterNames
                         }
                         this.symbol = symbol
                         dispatchReceiverType = firMethod.dispatchReceiverType

compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirExtensionSyntheticFunctionInterfaceProvider.kt

@@ -74,13 +74,16 @@ abstract class FirSyntheticFunctionInterfaceProviderBase(
     }
 
     @FirSymbolProviderInternals
-    override fun getTopLevelCallableSymbolsTo(destination: MutableList<FirCallableSymbol<*>>, packageFqName: FqName, name: Name) {}
+    override fun getTopLevelCallableSymbolsTo(destination: MutableList<FirCallableSymbol<*>>, packageFqName: FqName, name: Name) {
+    }
 
     @FirSymbolProviderInternals
-    override fun getTopLevelFunctionSymbolsTo(destination: MutableList<FirNamedFunctionSymbol>, packageFqName: FqName, name: Name) {}
+    override fun getTopLevelFunctionSymbolsTo(destination: MutableList<FirNamedFunctionSymbol>, packageFqName: FqName, name: Name) {
+    }
 
     @FirSymbolProviderInternals
-    override fun getTopLevelPropertySymbolsTo(destination: MutableList<FirPropertySymbol>, packageFqName: FqName, name: Name) {}
+    override fun getTopLevelPropertySymbolsTo(destination: MutableList<FirPropertySymbol>, packageFqName: FqName, name: Name) {
+    }
 
     override fun getPackage(fqName: FqName): FqName? {
         return fqName.takeIf { session.functionTypeService.hasKindWithSpecificPackage(it) }
@@ -162,6 +165,7 @@ abstract class FirSyntheticFunctionInterfaceProviderBase(
                     ).apply {
                         isOperator = true
                         isSuspend = kind.isSuspendOrKSuspendFunction
+                        hasStableParameterNames = false
                     }
                     val typeArguments = typeParameters.map {
                         ConeTypeParameterTypeImpl(it.symbol.toLookupTag(), false).toFirResolvedTypeRef()

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/ResolveUtils.kt

@@ -14,10 +14,7 @@ import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fakeElement
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.declarations.*
-import org.jetbrains.kotlin.fir.declarations.utils.canNarrowDownGetterType
+import org.jetbrains.kotlin.fir.declarations.utils.*
-import org.jetbrains.kotlin.fir.declarations.utils.expandedConeType
-import org.jetbrains.kotlin.fir.declarations.utils.isFinal
-import org.jetbrains.kotlin.fir.declarations.utils.modality
 import org.jetbrains.kotlin.fir.diagnostics.*
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.expressions.builder.*
@@ -560,20 +557,14 @@ fun FirFunction.getAsForbiddenNamedArgumentsTarget(
     // for intersection/substitution overrides
     originScope: FirTypeScope? = null
 ): ForbiddenNamedArgumentsTarget? {
-    if (this is FirConstructor && this.isPrimary) {
+    if (hasStableParameterNames) return null
-        this.getContainingClass(session)?.let { containingClass ->
+
-            if (containingClass.classKind == ClassKind.ANNOTATION_CLASS) {
-                // Java annotation classes allow (actually require) named parameters.
-                return null
-            }
-        }
-    }
     return when (origin) {
-        FirDeclarationOrigin.Source, FirDeclarationOrigin.Precompiled, FirDeclarationOrigin.Library -> null
         FirDeclarationOrigin.Delegated -> delegatedWrapperData?.wrapped?.getAsForbiddenNamedArgumentsTarget(session)
-        FirDeclarationOrigin.ImportedFromObjectOrStatic -> importedFromObjectOrStaticData?.original?.getAsForbiddenNamedArgumentsTarget(session)
+
-        is FirDeclarationOrigin.Java, FirDeclarationOrigin.Enhancement -> ForbiddenNamedArgumentsTarget.NON_KOTLIN_FUNCTION
+        FirDeclarationOrigin.ImportedFromObjectOrStatic ->
-        FirDeclarationOrigin.SamConstructor -> null
+            importedFromObjectOrStaticData?.original?.getAsForbiddenNamedArgumentsTarget(session)
+
         FirDeclarationOrigin.IntersectionOverride, FirDeclarationOrigin.SubstitutionOverride -> {
             var result: ForbiddenNamedArgumentsTarget? =
                 originalIfFakeOverride()?.getAsForbiddenNamedArgumentsTarget(session) ?: return null
@@ -587,25 +578,13 @@ fun FirFunction.getAsForbiddenNamedArgumentsTarget(
             }
             result
         }
-        // referenced function of a Kotlin function type
-        FirDeclarationOrigin.BuiltIns -> runIf(dispatchReceiverClassLookupTagOrNull()?.isSomeFunctionType(session) == true) {
-            ForbiddenNamedArgumentsTarget.INVOKE_ON_FUNCTION_TYPE
-        }
 
-        FirDeclarationOrigin.Synthetic,
+        FirDeclarationOrigin.BuiltIns -> ForbiddenNamedArgumentsTarget.INVOKE_ON_FUNCTION_TYPE
-        FirDeclarationOrigin.DynamicScope,
-        FirDeclarationOrigin.RenamedForOverride,
-        FirDeclarationOrigin.WrappedIntegerOperator,
-        FirDeclarationOrigin.ScriptCustomization,
         is FirDeclarationOrigin.Plugin -> null // TODO: figure out what to do with plugin generated functions
+        else -> ForbiddenNamedArgumentsTarget.NON_KOTLIN_FUNCTION
     }
 }
 
-// TODO: handle functions with non-stable parameter names, see also
-//  org.jetbrains.kotlin.fir.serialization.FirElementSerializer.functionProto
-//  org.jetbrains.kotlin.fir.serialization.FirElementSerializer.constructorProto
-fun FirFunction.getHasStableParameterNames(session: FirSession): Boolean = getAsForbiddenNamedArgumentsTarget(session) == null
-
 @OptIn(ExperimentalContracts::class)
 fun FirExpression?.isIntegerLiteralOrOperatorCall(): Boolean {
     contract {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/FirDeclarationStatus.kt

@@ -38,6 +38,7 @@ interface FirDeclarationStatus : FirElement {
     val isFromSealedClass: Boolean
     val isFromEnumClass: Boolean
     val isFun: Boolean
+    val hasStableParameterNames: Boolean
 
     override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitDeclarationStatus(this, data)
 

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/FirResolvedDeclarationStatus.kt

@@ -39,6 +39,7 @@ interface FirResolvedDeclarationStatus : FirDeclarationStatus {
     override val isFromSealedClass: Boolean
     override val isFromEnumClass: Boolean
     override val isFun: Boolean
+    override val hasStableParameterNames: Boolean
     val effectiveVisibility: EffectiveVisibility
 
     override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitResolvedDeclarationStatus(this, data)

compiler/fir/tree/src/org/jetbrains/kotlin/fir/Utils.kt

@@ -110,6 +110,7 @@ fun FirDeclarationStatus.copy(
     isFromSealedClass: Boolean = this.isFromSealedClass,
     isFromEnumClass: Boolean = this.isFromEnumClass,
     isFun: Boolean = this.isFun,
+    hasStableParameterNames: Boolean = this.hasStableParameterNames,
 ): FirDeclarationStatus {
     val newVisibility = visibility ?: this.visibility
     val newModality = modality ?: this.modality
@@ -137,6 +138,7 @@ fun FirDeclarationStatus.copy(
         this.isFromSealedClass = isFromSealedClass
         this.isFromEnumClass = isFromEnumClass
         this.isFun = isFun
+        this.hasStableParameterNames = hasStableParameterNames
     }
 }
 

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/impl/FirDeclarationStatusImpl.kt

@@ -20,7 +20,7 @@ open class FirDeclarationStatusImpl(
     override val modality: Modality?
 ) : FirPureAbstractElement(), FirDeclarationStatus {
     override val source: KtSourceElement? get() = null
-    protected var flags: Int = 0
+    protected var flags: Int = HAS_STABLE_PARAMETER_NAMES.mask
 
     operator fun get(modifier: Modifier): Boolean = (flags and modifier.mask) != 0
 
@@ -140,6 +140,12 @@ open class FirDeclarationStatusImpl(
             this[FUN] = value
         }
 
+    override var hasStableParameterNames: Boolean
+        get() = this[HAS_STABLE_PARAMETER_NAMES]
+        set(value) {
+            this[HAS_STABLE_PARAMETER_NAMES] = value
+        }
+
     enum class Modifier(val mask: Int) {
         EXPECT(0x1),
         ACTUAL(0x2),
@@ -158,7 +164,8 @@ open class FirDeclarationStatusImpl(
         STATIC(0x4000),
         FROM_SEALED(0x8000),
         FROM_ENUM(0x10000),
-        FUN(0x20000)
+        FUN(0x20000),
+        HAS_STABLE_PARAMETER_NAMES(0x40000),
     }
 
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/utils/FirStatusUtils.kt

@@ -46,6 +46,7 @@ inline val FirMemberDeclaration.isLateInit: Boolean get() = status.isLateInit
 inline val FirMemberDeclaration.isFromSealedClass: Boolean get() = status.isFromSealedClass
 inline val FirMemberDeclaration.isFromEnumClass: Boolean get() = status.isFromEnumClass
 inline val FirMemberDeclaration.isFun: Boolean get() = status.isFun
+inline val FirMemberDeclaration.hasStableParameterNames: Boolean get() = status.hasStableParameterNames
 
 inline val FirClassLikeDeclaration.isLocal: Boolean get() = symbol.classId.isLocal
 

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/NodeConfigurator.kt

@@ -382,7 +382,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
             generateBooleanFields(
                 "expect", "actual", "override", "operator", "infix", "inline", "tailRec",
                 "external", "const", "lateInit", "inner", "companion", "data", "suspend", "static",
-                "fromSealedClass", "fromEnumClass", "fun"
+                "fromSealedClass", "fromEnumClass", "fun", "hasStableParameterNames",
             )
         }
 

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/context/AbstractFieldConfigurator.kt

@@ -22,7 +22,7 @@ abstract class AbstractFieldConfigurator<T : AbstractFirTreeBuilder>(private val
 
         fun generateBooleanFields(vararg names: String) {
             names.forEach {
-                +booleanField("is${it.replaceFirstChar(Char::uppercaseChar)}")
+                +booleanField(if (it.startsWith("is") || it.startsWith("has")) it else "is${it.replaceFirstChar(Char::uppercaseChar)}")
             }
         }
 

compiler/testData/compileKotlinAgainstCustomBinaries/hasStableParameterNames/library/JavaInterface.java

@@ -0,0 +1,3 @@
+public interface JavaInterface {
+    public void foo(int javaName);
+}

compiler/testData/compileKotlinAgainstCustomBinaries/hasStableParameterNames/library/JavaSuperClass.java

@@ -0,0 +1,4 @@
+public class JavaSuperClass implements JavaInterface {
+    @Override
+    public void foo(int javaName) {}
+}

compiler/testData/compileKotlinAgainstCustomBinaries/hasStableParameterNames/library/KtClass.kt

@@ -0,0 +1 @@
+class KtClass : JavaInterface by JavaSuperClass()

compiler/testData/compileKotlinAgainstCustomBinaries/hasStableParameterNames/output.txt

@@ -0,0 +1 @@
+OK

compiler/testData/compileKotlinAgainstCustomBinaries/hasStableParameterNames/source.kt

@@ -0,0 +1,6 @@
+fun test() {
+    val ktInstance = KtClass()
+    // Shouldn't work but is kept for backward compatibility with K1
+    // When KT-4758 is fixed, this should break.
+    ktInstance.foo(javaName = 1)
+}

compiler/testData/diagnostics/tests/namedArguments/disallowForDelegationToJavaMethods.kt

@@ -0,0 +1,24 @@
+// FIR_IDENTICAL
+// SKIP_TXT
+
+// FILE: JavaInterface.java
+
+public interface JavaInterface {
+    public void foo(int javaName);
+}
+
+// FILE: JavaClass.java
+
+public class JavaSuperClass implements JavaInterface {
+    @Override
+    public void foo(int javaName) {}
+}
+
+// FILE: 1.kt
+
+class KtClass: JavaInterface by JavaSuperClass()
+
+fun test() {
+    val ktInstance = KtClass()
+    ktInstance.foo(<!NAMED_ARGUMENTS_NOT_ALLOWED!>javaName<!> = 1)
+}

compiler/testData/diagnostics/tests/namedArguments/disallowForFunctionTypes.kt

@@ -0,0 +1,6 @@
+// FIR_IDENTICAL
+// SKIP_TXT
+
+fun test(f: (String) -> Unit) {
+    f(<!NAMED_ARGUMENTS_NOT_ALLOWED!>p1<!> = "")
+}

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

@@ -22100,6 +22100,18 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/namedArguments/ambiguousNamedArgumentsWithGenerics3.kt");
             }
 
+            @Test
+            @TestMetadata("disallowForDelegationToJavaMethods.kt")
+            public void testDisallowForDelegationToJavaMethods() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForDelegationToJavaMethods.kt");
+            }
+
+            @Test
+            @TestMetadata("disallowForFunctionTypes.kt")
+            public void testDisallowForFunctionTypes() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/namedArguments/disallowForFunctionTypes.kt");
+            }
+
             @Test
             @TestMetadata("disallowForJavaConstructor.kt")
             public void testDisallowForJavaConstructor() throws Exception {

compiler/tests/org/jetbrains/kotlin/jvm/compiler/CompileKotlinAgainstCustomBinariesTest.kt

@@ -371,6 +371,11 @@ class CompileKotlinAgainstCustomBinariesTest : AbstractKotlinCompilerIntegration
         compileKotlin("source.kt", tmpdir, listOf(compileLibrary("library")))
     }
 
+    fun testHasStableParameterNames() {
+        val library = compileLibrary("library", additionalOptions = listOf("-language-version", "2.0"))
+        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-language-version", "2.0"))
+    }
+
     fun testRequireKotlinInNestedClasses() {
         compileKotlin("source.kt", tmpdir, listOf(compileLibrary("library")))
     }