Fix code review

Minor fixes
Fix JVM IR BE
Fix NATIVE

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt

@@ -221,7 +221,7 @@ open class WrappedSimpleFunctionDescriptor(
 
     val extensionReceiver by lazy {
         owner.extensionReceiverParameter?.let {
-            ReceiverParameterDescriptorImpl(this, ExtensionReceiver(it.descriptor, it.type.toKotlinType(), null))
+            ReceiverParameterDescriptorImpl(this, ExtensionReceiver(it.descriptor, it.type.toKotlinType(), null), Annotations.EMPTY)
         }
     }
 
@@ -294,6 +294,9 @@ open class WrappedClassConstructorDescriptor(
 ) : ClassConstructorDescriptor, WrappedCallableDescriptor<IrConstructor>(annotations, sourceElement) {
     override fun getContainingDeclaration() = (owner.parent as IrClass).descriptor
 
+    override fun getDispatchReceiverParameter() = owner.dispatchReceiverParameter?.run {
+        (containingDeclaration.containingDeclaration as ClassDescriptor).thisAsReceiverParameter
+    }
     override fun getTypeParameters() = owner.typeParameters.map { it.descriptor }
     override fun getValueParameters() = owner.valueParameters.asSequence()
         .mapNotNull { it.descriptor as? ValueParameterDescriptor }

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/ir/IrUtils.kt

@@ -158,6 +158,7 @@ fun IrValueParameter.copyTo(irFunction: IrFunction, shift: Int = 0): IrValuePara
 }
 
 fun IrTypeParameter.copyTo(irFunction: IrFunction, shift: Int = 0): IrTypeParameter {
+    // TODO: Copy IrTypeParameter with type remapping
     val descriptor = WrappedTypeParameterDescriptor(symbol.descriptor.annotations, symbol.descriptor.source)
     val symbol = IrTypeParameterSymbolImpl(descriptor)
     return IrTypeParameterImpl(startOffset, endOffset, origin, symbol, name, shift + index, isReified, variance).also {
@@ -168,7 +169,12 @@ fun IrTypeParameter.copyTo(irFunction: IrFunction, shift: Int = 0): IrTypeParame
 
 fun IrFunction.copyParameterDeclarationsFrom(from: IrFunction) {
 
-    dispatchReceiverParameter = from.dispatchReceiverParameter?.copyTo(this)
+    // TODO: should dispatch receiver be copied?
+    dispatchReceiverParameter = from.dispatchReceiverParameter?.let {
+        IrValueParameterImpl(it.startOffset, it.endOffset, it.origin, it.descriptor, it.type, it.varargElementType).also {
+            it.parent = this
+        }
+    }
     extensionReceiverParameter = from.extensionReceiverParameter?.copyTo(this)
 
     val shift = valueParameters.size

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

@@ -15,17 +15,16 @@ import org.jetbrains.kotlin.backend.common.descriptors.WrappedValueParameterDesc
 import org.jetbrains.kotlin.backend.common.descriptors.synthesizedName
 import org.jetbrains.kotlin.backend.common.ir.copyTo
 import org.jetbrains.kotlin.backend.common.ir.ir2string
+import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrConstructorImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
 import org.jetbrains.kotlin.ir.expressions.*
-import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrConstImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrDelegatingConstructorCallImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrGetObjectValueImpl
+import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.impl.IrConstructorSymbolImpl
@@ -142,9 +141,9 @@ open class DefaultArgumentStubGenerator constructor(val context: CommonBackendCo
                 }
             }
             // Remove default argument initializers.
-//            irFunction.valueParameters.forEach {
-//                it.defaultValue = null
-//            }
+            irFunction.valueParameters.forEach {
+                it.defaultValue = IrExpressionBodyImpl(IrErrorExpressionImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, it.type, "Default Stub"))
+            }
 
             return listOf(irFunction, newIrFunction)
         }
@@ -377,7 +376,9 @@ private fun IrFunction.generateDefaultsFunctionImpl(context: CommonBackendContex
     val newTypeParameters = typeParameters.map { it.copyTo(newFunction) }
 
     newFunction.returnType = returnType
-    newFunction.dispatchReceiverParameter = dispatchReceiverParameter?.copyTo(newFunction)
+    newFunction.dispatchReceiverParameter = dispatchReceiverParameter?.run {
+        IrValueParameterImpl(startOffset, endOffset, origin, descriptor, type, varargElementType).also { it.parent = newFunction }
+    }
     newFunction.extensionReceiverParameter = extensionReceiverParameter?.copyTo(newFunction)
     newFunction.valueParameters += newValueParameters
     newFunction.typeParameters += newTypeParameters
@@ -399,7 +400,7 @@ private fun buildFunctionDeclaration(irFunction: IrFunction): IrFunction {
                 irFunction.name,
                 irFunction.visibility,
                 irFunction.isInline,
-                irFunction.isExternal,
+                false,
                 false
             ).also {
                 descriptor.bind(it)
@@ -417,10 +418,10 @@ private fun buildFunctionDeclaration(irFunction: IrFunction): IrFunction {
                 IrSimpleFunctionSymbolImpl(descriptor),
                 name,
                 irFunction.visibility,
-                irFunction.modality,
+                Modality.FINAL,
                 irFunction.isInline,
-                irFunction.isExternal,
-                irFunction.isTailrec,
+                false,
+                false,
                 irFunction.isSuspend
             ).also {
                 descriptor.bind(it)

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

@@ -55,7 +55,7 @@ class LocalDeclarationsLowering(
     val context: BackendContext,
     val localNameProvider: LocalNameProvider = LocalNameProvider.DEFAULT,
     val loweredConstructorVisibility: Visibility = Visibilities.PRIVATE,
-    private val isJVM: Boolean = false
+    private val isJVM: Boolean = false // TODO: remove this workaround
 ) :
     DeclarationContainerLoweringPass {
 
@@ -350,7 +350,7 @@ class LocalDeclarationsLowering(
             override fun visitReturn(expression: IrReturn): IrExpression {
                 expression.transformChildrenVoid(this)
 
-                val oldReturnTarget = expression.returnTargetSymbol.owner as IrFunction
+                val oldReturnTarget = expression.returnTargetSymbol.owner as? IrFunction ?: return expression
                 val newReturnTarget = oldReturnTarget.transformed ?: return expression
 
                 return IrReturnImpl(
@@ -503,7 +503,7 @@ class LocalDeclarationsLowering(
                 newSymbol,
                 newName,
                 // TODO: change to PRIVATE when issue with CallableReferenceLowering in Jvm BE is fixed
-                Visibilities.PUBLIC,
+                if (isJVM) Visibilities.PUBLIC else Visibilities.PRIVATE,
                 Modality.FINAL,
                 oldDeclaration.isInline,
                 oldDeclaration.isExternal,
@@ -596,8 +596,10 @@ class LocalDeclarationsLowering(
 
             newDeclaration.parent = localClassContext.declaration
             newDeclaration.returnType = oldDeclaration.returnType
+            // TODO: should dispatch receiver be copied?
             newDeclaration.dispatchReceiverParameter = oldDeclaration.dispatchReceiverParameter?.run {
-                copyTo(newDeclaration).also {
+                IrValueParameterImpl(startOffset, endOffset, origin, descriptor, type, varargElementType).also {
+                    it.parent = newDeclaration
                     newParameterToOld.putAbsentOrSame(it, this)
                 }
             }

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

@@ -68,6 +68,11 @@ class VariableRemapper(val mapping: Map<IrValueParameter, IrValueParameter>) : A
         mapping[value]
 }
 
+class VariableRemapperDesc(val mapping: Map<ValueDescriptor, IrValueParameter>) : AbstractVariableRemapper() {
+    override fun remapVariable(value: IrValueDeclaration): IrValueParameter? =
+        mapping[value.descriptor]
+}
+
 fun BackendContext.createIrBuilder(
     symbol: IrSymbol,
     startOffset: Int = UNDEFINED_OFFSET,