FIR2IR: Do not add fake override if the member is overridden

#KT-56398

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/actualizer/MissingFakeOverridesAdder.kt

@@ -6,13 +6,13 @@
 package org.jetbrains.kotlin.backend.common.actualizer
 
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.builders.declarations.buildFun
+import org.jetbrains.kotlin.ir.builders.declarations.buildProperty
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrPropertyImpl
 import org.jetbrains.kotlin.ir.symbols.IrPropertySymbol
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
-import org.jetbrains.kotlin.ir.symbols.impl.IrPropertySymbolImpl
-import org.jetbrains.kotlin.ir.symbols.impl.IrSimpleFunctionSymbolImpl
 import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.ir.types.isAny
 import org.jetbrains.kotlin.ir.util.deepCopyWithSymbols
@@ -48,6 +48,7 @@ class MissingFakeOverridesAdder(
             for (expectMember in expectClass.declarations) {
                 if (expectMember.isBuiltinMember()) continue
                 val actualMember = expectActualMap[expectMember.symbol]?.owner as? IrDeclaration ?: continue
+                added += actualMember
 
                 // Do not add FAKE_OVERRIDE if the subclass already has overridden member
                 if (declaration.declarations.filterIsInstance<IrOverridableDeclaration<*>>()
@@ -56,7 +57,6 @@ class MissingFakeOverridesAdder(
                     continue
                 }
                 addFakeOverride(actualMember, members, declaration)
-                added += actualMember
             }
             val actualClass = expectActualMap[expectClass.symbol]?.owner as? IrClass ?: continue
             for (actualMember in actualClass.declarations) {
@@ -96,56 +96,35 @@ private fun IrDeclaration.isBuiltinMember(): Boolean {
 }
 
 private fun createFakeOverrideProperty(actualMember: IrPropertyImpl, declaration: IrClass) =
-    IrPropertyImpl(
+    declaration.factory.buildProperty {
-        actualMember.startOffset,
+        updateFrom(actualMember)
-        actualMember.endOffset,
+        name = actualMember.name
-        IrDeclarationOrigin.FAKE_OVERRIDE,
+        origin = IrDeclarationOrigin.FAKE_OVERRIDE
-        IrPropertySymbolImpl(),
+    }.apply {
-        actualMember.name,
+        parent = declaration
-        actualMember.visibility,
+        annotations = actualMember.annotations
-        actualMember.modality,
+        backingField = actualMember.backingField
-        actualMember.isVar,
+        getter = (actualMember.getter as? IrFunctionImpl)?.let { getter ->
-        actualMember.isConst,
+            createFakeOverrideFunction(getter, declaration, symbol)
-        actualMember.isLateinit,
-        actualMember.isDelegated,
-        isExternal = actualMember.isExternal
-    ).also {
-        it.parent = declaration
-        it.annotations = actualMember.annotations
-        it.backingField = actualMember.backingField
-        it.getter = (actualMember.getter as? IrFunctionImpl)?.let { getter ->
-            createFakeOverrideFunction(getter, declaration, it.symbol)
         }
-        it.setter = (actualMember.setter as? IrFunctionImpl)?.let { setter ->
+        setter = (actualMember.setter as? IrFunctionImpl)?.let { setter ->
-            createFakeOverrideFunction(setter, declaration, it.symbol)
+            createFakeOverrideFunction(setter, declaration, symbol)
         }
-        it.overriddenSymbols = listOf(actualMember.symbol)
+        overriddenSymbols = listOf(actualMember.symbol)
-        it.metadata = actualMember.metadata
-        it.attributeOwnerId = it
     }
 
 private fun createFakeOverrideFunction(
     actualFunction: IrFunctionImpl,
     parent: IrDeclarationParent,
     correspondingPropertySymbol: IrPropertySymbol? = null
-) =
+) = actualFunction.factory.buildFun {
-    IrFunctionImpl(
+    updateFrom(actualFunction)
-        actualFunction.startOffset,
+    name = actualFunction.name
-        actualFunction.endOffset,
+    returnType = actualFunction.returnType
-        IrDeclarationOrigin.FAKE_OVERRIDE,
+    origin = IrDeclarationOrigin.FAKE_OVERRIDE
-        IrSimpleFunctionSymbolImpl(),
+    isFakeOverride = true
-        actualFunction.name,
-        actualFunction.visibility,
-        actualFunction.modality,
-        actualFunction.returnType,
-        actualFunction.isInline,
-        actualFunction.isExternal,
-        actualFunction.isTailrec,
-        actualFunction.isSuspend,
-        actualFunction.isOperator,
-        actualFunction.isInfix,
     isExpect = false
-    ).also {
+}.also {
     it.parent = parent
     it.annotations = actualFunction.annotations.map { p -> p.deepCopyWithSymbols(it) }
     it.typeParameters = actualFunction.typeParameters.map { p -> p.deepCopyWithSymbols(it) }
@@ -157,4 +136,4 @@ private fun createFakeOverrideFunction(
     it.overriddenSymbols = listOf(actualFunction.symbol)
     it.attributeOwnerId = it
     it.correspondingPropertySymbol = correspondingPropertySymbol
-    }
+}