Eliminated all hacks related to IR bugs with delegated descriptors.

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Context.kt

@@ -71,8 +71,7 @@ internal class SpecialDescriptorsFactory(val context: Context) {
 
         bridgeDescriptor.initialize(
                 extensionReceiverType,
-                // TODO: bug in descriptor - https://youtrack.jetbrains.com/issue/KT-16438.
-                (descriptor.containingDeclaration as ClassDescriptor).thisAsReceiverParameter,
+                descriptor.dispatchReceiverParameter,
                 descriptor.typeParameters,
                 descriptor.valueParameters.mapIndexed { index, valueParameterDescriptor ->
                     when (bridgeDirections[index + 2]) {

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanLower.kt

@@ -32,7 +32,6 @@ internal class KonanLower(val context: Context) {
             InitializersLowering(context).runOnFilePostfix(irFile)
         }
         phaser.phase(KonanPhase.LOWER_DELEGATION) {
-            ClassDelegationLowering(context).runOnFilePostfix(irFile)
             PropertyDelegationLowering(context).lower(irFile)
         }
         phaser.phase(KonanPhase.LOWER_TYPE_OPERATORS) {

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/descriptors/ClassVtablesBuilder.kt

@@ -15,8 +15,7 @@ internal class OverriddenFunctionDescriptor(val descriptor: FunctionDescriptor,
     val needBridge: Boolean
         get() {
             if (descriptor.modality == Modality.ABSTRACT) return false
-            return descriptor.kind == CallableMemberDescriptor.Kind.DELEGATION
-                    || descriptor.target.needBridgeTo(overriddenDescriptor)
+            return descriptor.target.needBridgeTo(overriddenDescriptor)
         }
 
     val bridgeDirections: BridgeDirections

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -13,8 +13,6 @@ import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltinOperatorDescriptorBase
-import org.jetbrains.kotlin.ir.descriptors.IrImplementingDelegateDescriptorImpl
-import org.jetbrains.kotlin.ir.descriptors.IrPropertyDelegateDescriptorImpl
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.util.getArguments
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
@@ -1246,10 +1244,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
 
     private fun evaluateGetField(value: IrGetField): LLVMValueRef {
         context.log("evaluateGetField           : ${ir2string(value)}")
-        if (value.descriptor.dispatchReceiverParameter != null
-                // TODO: hack because of IR bug: https://github.com/JetBrains/kotlin/tree/rr/dispatch_receiver_for_delegate_descriptor.
-                || value.descriptor is IrImplementingDelegateDescriptorImpl
-                || (value.descriptor is IrPropertyDelegateDescriptorImpl && value.descriptor.containingDeclaration is ClassDescriptor)) {
+        if (value.descriptor.dispatchReceiverParameter != null) {
             val thisPtr = evaluateExpression(value.receiver!!)
             return codegen.loadSlot(
                     fieldPtrOfClass(thisPtr, value.descriptor), value.descriptor.isVar())
@@ -1279,10 +1274,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         context.log("evaluateSetField           : ${ir2string(value)}")
         val valueToAssign = evaluateExpression(value.value)
 
-        if (value.descriptor.dispatchReceiverParameter != null
-                // TODO: hack because of IR bug: https://github.com/JetBrains/kotlin/tree/rr/dispatch_receiver_for_delegate_descriptor.
-                || value.descriptor is IrImplementingDelegateDescriptorImpl
-                || (value.descriptor is IrPropertyDelegateDescriptorImpl && value.descriptor.containingDeclaration is ClassDescriptor)) {
+        if (value.descriptor.dispatchReceiverParameter != null) {
             val thisPtr = evaluateExpression(value.receiver!!)
             codegen.storeAnyGlobal(valueToAssign, fieldPtrOfClass(thisPtr, value.descriptor))
         }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmDeclarations.kt

@@ -7,8 +7,6 @@ import org.jetbrains.kotlin.backend.konan.descriptors.*
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.descriptors.IrImplementingDelegateDescriptorImpl
-import org.jetbrains.kotlin.ir.descriptors.IrPropertyDelegateDescriptorImpl
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
 import org.jetbrains.kotlin.name.FqName
@@ -298,13 +296,8 @@ private class DeclarationsGeneratorVisitor(override val context: Context) :
         val descriptor = declaration.descriptor
 
         val dispatchReceiverParameter = descriptor.dispatchReceiverParameter
-        if (dispatchReceiverParameter != null
-                // TODO: hack because of IR bug: https://github.com/JetBrains/kotlin/tree/rr/dispatch_receiver_for_delegate_descriptor.
-                || descriptor is IrImplementingDelegateDescriptorImpl
-                || (descriptor is IrPropertyDelegateDescriptorImpl && descriptor.containingDeclaration is ClassDescriptor)) {
-            val containingClass = dispatchReceiverParameter?.containingDeclaration
-                    // TODO: hack because of IR bug: https://github.com/JetBrains/kotlin/tree/rr/dispatch_receiver_for_delegate_descriptor.
-                    ?: descriptor.containingDeclaration
+        if (dispatchReceiverParameter != null) {
+            val containingClass = dispatchReceiverParameter.containingDeclaration
             val classDeclarations = this.classes[containingClass] ?: error(containingClass.toString())
 
             val allFields = classDeclarations.fields

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/BridgesBuilding.kt

@@ -34,20 +34,11 @@ internal class DirectBridgesCallsLowering(val context: Context) : BodyLoweringPa
                 }
 
                 val target = descriptor.target
-                val needBridge = descriptor.original.needBridgeTo(target)
-                if (descriptor.kind != CallableMemberDescriptor.Kind.DELEGATION && !needBridge)
-                    return expression
-
-                val toCall = if (needBridge) {
-                    target
-                } else {
-                    // Need to call delegating function.
-                    context.specialDescriptorsFactory.getBridgeDescriptor(OverriddenFunctionDescriptor(descriptor, target))
-                }
+                if (!descriptor.original.needBridgeTo(target)) return expression
 
                 return IrCallImpl(expression.startOffset, expression.endOffset,
-                        toCall, remapTypeArguments(expression, toCall), expression.origin,
-                        superQualifier = toCall.containingDeclaration as ClassDescriptor /* Call non-virtually */).apply {
+                        target, remapTypeArguments(expression, target), expression.origin,
+                        superQualifier = target.containingDeclaration as ClassDescriptor /* Call non-virtually */).apply {
                     dispatchReceiver = expression.dispatchReceiver
                     extensionReceiver = expression.extensionReceiver
                     mapValueParameters { expression.getValueArgument(it)!! }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/DelegationLowering.kt

@@ -27,66 +27,6 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.types.*
 
-internal class ClassDelegationLowering(val context: Context) : DeclarationContainerLoweringPass {
-    override fun lower(irDeclarationContainer: IrDeclarationContainer) {
-        irDeclarationContainer.declarations.transformFlat {
-            when (it) {
-                is IrFunction -> {
-                    val transformedFun = transformBridgeToDelegatedMethod(irDeclarationContainer, it)
-                    if (transformedFun == null) null
-                    else listOf(transformedFun)
-                }
-                is IrProperty -> {
-                    val getter = transformBridgeToDelegatedMethod(irDeclarationContainer, it.getter)
-                    val setter = transformBridgeToDelegatedMethod(irDeclarationContainer, it.setter)
-                    if (getter != null) it.getter = getter
-                    if (setter != null) it.setter = setter
-                    null
-                }
-                else -> null
-            }
-        }
-    }
-
-    private fun transformBridgeToDelegatedMethod(irDeclarationContainer: IrDeclarationContainer, irFunction: IrFunction?): IrFunction? {
-        if (irFunction == null) return null
-        val descriptor = irFunction.descriptor
-
-        if (descriptor.kind != CallableMemberDescriptor.Kind.DELEGATION) return null
-
-        // TODO: hack because of broken IR for synthesized delegated members: https://youtrack.jetbrains.com/issue/KT-16486.
-        val body = irFunction.body as? IrBlockBody
-                ?: throw AssertionError("Unexpected method body: ${irFunction.body}")
-        val statement = body.statements.single()
-        val delegatedCall = ((statement as? IrReturn)?.value ?: statement) as? IrCall
-                ?: throw AssertionError("Unexpected method body: $statement")
-        val delegated = context.specialDescriptorsFactory.getBridgeDescriptor(
-                OverriddenFunctionDescriptor(descriptor, delegatedCall.descriptor as FunctionDescriptor))
-        val newFunction = IrFunctionImpl(irFunction.startOffset, irFunction.endOffset, irFunction.origin, delegated)
-
-        val irBlockBody = IrBlockBodyImpl(irFunction.startOffset, irFunction.endOffset)
-        val returnType = delegatedCall.descriptor.returnType!!
-        val irCall = IrCallImpl(irFunction.startOffset, irFunction.endOffset, returnType, delegatedCall.descriptor, null)
-        irCall.dispatchReceiver = delegatedCall.dispatchReceiver
-        irCall.extensionReceiver = delegated.extensionReceiverParameter?.let { extensionReceiver ->
-            IrGetValueImpl(irFunction.startOffset, irFunction.endOffset, extensionReceiver)
-        }
-        irCall.mapValueParameters { overriddenValueParameter ->
-            val delegatedValueParameter = delegated.valueParameters[overriddenValueParameter.index]
-            IrGetValueImpl(irFunction.startOffset, irFunction.endOffset, delegatedValueParameter)
-        }
-        if (KotlinBuiltIns.isUnit(returnType) || KotlinBuiltIns.isNothing(returnType)) {
-            irBlockBody.statements.add(irCall)
-        } else {
-            val irReturn = IrReturnImpl(irFunction.startOffset, irFunction.endOffset, context.builtIns.nothingType, delegated, irCall)
-            irBlockBody.statements.add(irReturn)
-        }
-
-        newFunction.body = irBlockBody
-        return newFunction
-    }
-}
-
 internal class PropertyDelegationLowering(val context: Context) : FileLoweringPass {
     private val kotlinReflectPackage = context.irModule!!.descriptor.getPackage(FqName.fromSegments(listOf("kotlin", "reflect")))
     private val genericKPropertyImplType = kotlinReflectPackage.memberScope.getContributedClassifier(Name.identifier("KPropertyImpl"),