Do not generate interface delegation for default parameter stubs

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/DefaultArgumentStubGenerator.kt

@@ -69,7 +69,7 @@ open class DefaultArgumentStubGenerator constructor(val context: CommonBackendCo
         }
 
         val newIrFunction =
-            irFunction.generateDefaultsFunction(context, DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER, skipInlineMethods)
+            irFunction.generateDefaultsFunction(context, IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER, skipInlineMethods)
 
         log { "$irFunction -> $newIrFunction" }
         val builder = context.createIrBuilder(newIrFunction.symbol)
@@ -273,7 +273,7 @@ open class DefaultParameterInjector constructor(
 
                 val keyFunction = declaration.findSuperMethodWithDefaultArguments()!!
                 val realFunction =
-                    keyFunction.generateDefaultsFunction(context, DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER, skipInline)
+                    keyFunction.generateDefaultsFunction(context, IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER, skipInline)
 
                 log { "$declaration -> $realFunction" }
                 val maskValues = Array((declaration.valueParameters.size + 31) / 32) { 0 }
@@ -403,7 +403,7 @@ private fun IrFunction.generateDefaultsFunctionImpl(
             val baseFun = baseFunSymbol.owner
             if (baseFun.needsDefaultArgumentsLowering(skipInlineMethods)) {
                 val baseOrigin = if (baseFun.valueParameters.any { it.defaultValue != null }) {
-                    DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER
+                    IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER
                 } else {
                     IrDeclarationOrigin.FAKE_OVERRIDE
                 }
@@ -447,7 +447,7 @@ private fun buildFunctionDeclaration(irFunction: IrFunction, origin: IrDeclarati
                 IrSimpleFunctionSymbolImpl(descriptor),
                 name,
                 irFunction.visibility,
-                if (irFunction.modality === Modality.ABSTRACT) Modality.OPEN else irFunction.modality,
+                Modality.FINAL,
                 irFunction.returnType,
                 irFunction.isInline,
                 false,
@@ -471,9 +471,6 @@ private fun IrFunction.generateDefaultsFunction(
         generateDefaultsFunctionImpl(context, origin, skipInlineMethods)
     }
 
-object DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER :
-    IrDeclarationOriginImpl("DEFAULT_PARAMETER_EXTENT")
-
 private fun IrFunction.valueParameter(index: Int, name: Name, type: IrType): IrValueParameter {
     val parameterDescriptor = WrappedValueParameterDescriptor()
 

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/FunctionCodegen.kt

@@ -5,7 +5,6 @@
 
 package org.jetbrains.kotlin.backend.jvm.codegen
 
-import org.jetbrains.kotlin.backend.common.lower.DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER
 import org.jetbrains.kotlin.backend.jvm.JvmLoweredDeclarationOrigin
 import org.jetbrains.kotlin.backend.jvm.descriptors.JvmDescriptorWithExtraFlags
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns.FQ_NAMES
@@ -62,7 +61,7 @@ open class FunctionCodegen(private val irFunction: IrFunction, private val class
     }
 
     private fun calculateMethodFlags(isStatic: Boolean): Int {
-        if (irFunction.origin == DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER) {
+        if (irFunction.origin == IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER) {
             return Opcodes.ACC_PUBLIC or Opcodes.ACC_SYNTHETIC.let {
                 if (irFunction is IrConstructor) it else it or Opcodes.ACC_BRIDGE or Opcodes.ACC_STATIC
             }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceDelegationLowering.kt

@@ -135,5 +135,6 @@ class InterfaceDelegationLowering(val context: JvmBackendContext) : IrElementTra
 
     private fun IrSimpleFunction.isDefinitelyNotDefaultImplsMethod() =
         resolveFakeOverride()?.let { origin == IrDeclarationOrigin.IR_EXTERNAL_JAVA_DECLARATION_STUB } == true ||
+                origin == IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER ||
                 hasAnnotation(PLATFORM_DEPENDENT_ANNOTATION_FQ_NAME)
 }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceLowering.kt

@@ -9,7 +9,6 @@ import org.jetbrains.kotlin.backend.common.ClassLoweringPass
 import org.jetbrains.kotlin.backend.common.descriptors.WrappedSimpleFunctionDescriptor
 import org.jetbrains.kotlin.backend.common.ir.copyTo
 import org.jetbrains.kotlin.backend.common.ir.copyTypeParametersFrom
-import org.jetbrains.kotlin.backend.common.lower.DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER
 import org.jetbrains.kotlin.backend.common.lower.InitializersLowering.Companion.clinitName
 import org.jetbrains.kotlin.backend.common.lower.VariableRemapper
 import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
@@ -53,7 +52,7 @@ class InterfaceLowering(val context: JvmBackendContext) : IrElementTransformerVo
         }
 
         val defaultBodies = irClass.declarations.filterIsInstance<IrFunction>().filter {
-            it.origin == DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER
+            it.origin == IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER
         }
         irClass.declarations.removeAll(privateToRemove)
         irClass.declarations.removeAll(defaultBodies)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/StaticDefaultFunctionLowering.kt

@@ -18,23 +18,21 @@ package org.jetbrains.kotlin.backend.jvm.lower
 
 import org.jetbrains.kotlin.backend.common.BackendContext
 import org.jetbrains.kotlin.backend.common.ClassLoweringPass
-import org.jetbrains.kotlin.backend.common.lower.DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER
-import org.jetbrains.kotlin.backend.common.makePhase
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
 import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 
 class StaticDefaultFunctionLowering() : IrElementTransformerVoid(), ClassLoweringPass {
     constructor(@Suppress("UNUSED_PARAMETER") context: BackendContext) : this()
 
-
     override fun lower(irClass: IrClass) {
         irClass.accept(this, null)
     }
 
     override fun visitFunction(declaration: IrFunction): IrStatement {
-        return if (declaration.origin == DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER && declaration.dispatchReceiverParameter != null) {
+        return if (declaration.origin == IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER && declaration.dispatchReceiverParameter != null) {
             createStaticFunctionWithReceivers(declaration.parent, declaration.name, declaration)
         } else {
             super.visitFunction(declaration)

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrDeclarationOrigin.kt

@@ -28,6 +28,7 @@ interface IrDeclarationOrigin {
     object DELEGATED_PROPERTY_ACCESSOR : IrDeclarationOriginImpl("DELEGATED_PROPERTY_ACCESSOR")
     object DELEGATED_MEMBER : IrDeclarationOriginImpl("DELEGATED_MEMBER")
     object ENUM_CLASS_SPECIAL_MEMBER : IrDeclarationOriginImpl("ENUM_CLASS_SPECIAL_MEMBER")
+    object FUNCTION_FOR_DEFAULT_PARAMETER : IrDeclarationOriginImpl("FUNCTION_FOR_DEFAULT_PARAMETER")
     object GENERATED_DATA_CLASS_MEMBER : IrDeclarationOriginImpl("GENERATED_DATA_CLASS_MEMBER")
     object GENERATED_INLINE_CLASS_MEMBER : IrDeclarationOriginImpl("GENERATED_INLINE_CLASS_MEMBER")
     object LOCAL_FUNCTION_FOR_LAMBDA : IrDeclarationOriginImpl("LOCAL_FUNCTION_FOR_LAMBDA")