JS IR: make PIR Carriers immutable

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrAnonymousInitializer.kt

@@ -56,7 +56,8 @@ internal class PersistentIrAnonymousInitializer(
                 if (v is PersistentIrBodyBase<*>) {
                     v.container = this
                 }
-                setCarrier().bodyField = v
+                setCarrier()
+                bodyField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrClass.kt

@@ -76,7 +76,8 @@ internal class PersistentIrClass(
         get() = getCarrier().visibilityField
         set(v) {
             if (visibility !== v) {
-                setCarrier().visibilityField = v
+                setCarrier()
+                visibilityField = v
             }
         }
 
@@ -86,7 +87,8 @@ internal class PersistentIrClass(
         get() = getCarrier().thisReceiverField
         set(v) {
             if (thisReceiver !== v) {
-                setCarrier().thisReceiverField = v
+                setCarrier()
+                thisReceiverField = v
             }
         }
 
@@ -112,7 +114,8 @@ internal class PersistentIrClass(
         get() = getCarrier().typeParametersField
         set(v) {
             if (typeParameters !== v) {
-                setCarrier().typeParametersField = v
+                setCarrier()
+                typeParametersField = v
             }
         }
 
@@ -122,7 +125,8 @@ internal class PersistentIrClass(
         get() = getCarrier().superTypesField
         set(v) {
             if (superTypes !== v) {
-                setCarrier().superTypesField = v
+                setCarrier()
+                superTypesField = v
             }
         }
 
@@ -132,7 +136,8 @@ internal class PersistentIrClass(
         get() = getCarrier().metadataField
         set(v) {
             if (metadata !== v) {
-                setCarrier().metadataField = v
+                setCarrier()
+                metadataField = v
             }
         }
 
@@ -142,7 +147,8 @@ internal class PersistentIrClass(
         get() = getCarrier().modalityField
         set(v) {
             if (modality !== v) {
-                setCarrier().modalityField = v
+                setCarrier()
+                modalityField = v
             }
         }
 
@@ -152,7 +158,8 @@ internal class PersistentIrClass(
         get() = getCarrier().isExternalField
         set(v) {
             if (isExternal != v) {
-                setCarrier().isExternalField = v
+                setCarrier()
+                isExternalField = v
             }
         }
 
@@ -162,7 +169,8 @@ internal class PersistentIrClass(
         get() = getCarrier().attributeOwnerIdField
         set(v) {
             if (attributeOwnerId !== v) {
-                setCarrier().attributeOwnerIdField = v
+                setCarrier()
+                attributeOwnerIdField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrConstructor.kt

@@ -65,7 +65,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().returnTypeFieldField
         set(v) {
             if (returnTypeField !== v) {
-                setCarrier().returnTypeFieldField = v
+                setCarrier()
+                returnTypeFieldField = v
             }
         }
 
@@ -83,7 +84,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().typeParametersField
         set(v) {
             if (typeParameters !== v) {
-                setCarrier().typeParametersField = v
+                setCarrier()
+                typeParametersField = v
             }
         }
 
@@ -93,7 +95,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().dispatchReceiverParameterField
         set(v) {
             if (dispatchReceiverParameter !== v) {
-                setCarrier().dispatchReceiverParameterField = v
+                setCarrier()
+                dispatchReceiverParameterField = v
             }
         }
 
@@ -103,7 +106,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().extensionReceiverParameterField
         set(v) {
             if (extensionReceiverParameter !== v) {
-                setCarrier().extensionReceiverParameterField = v
+                setCarrier()
+                extensionReceiverParameterField = v
             }
         }
 
@@ -113,7 +117,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().valueParametersField
         set(v) {
             if (valueParameters !== v) {
-                setCarrier().valueParametersField = v
+                setCarrier()
+                valueParametersField = v
             }
         }
 
@@ -126,7 +131,8 @@ internal class PersistentIrConstructor(
                 if (v is PersistentIrBodyBase<*>) {
                     v.container = this
                 }
-                setCarrier().bodyField = v
+                setCarrier()
+                bodyField = v
             }
         }
 
@@ -136,7 +142,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().metadataField
         set(v) {
             if (metadata !== v) {
-                setCarrier().metadataField = v
+                setCarrier()
+                metadataField = v
             }
         }
 
@@ -146,7 +153,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().visibilityField
         set(v) {
             if (visibility !== v) {
-                setCarrier().visibilityField = v
+                setCarrier()
+                visibilityField = v
             }
         }
 
@@ -156,7 +164,8 @@ internal class PersistentIrConstructor(
         get() = getCarrier().isExternalField
         set(v) {
             if (isExternal != v) {
-                setCarrier().isExternalField = v
+                setCarrier()
+                isExternalField = v
             }
         }
 

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrEnumEntry.kt

@@ -55,7 +55,8 @@ internal class PersistentIrEnumEntry(
         get() = getCarrier().correspondingClassField
         set(v) {
             if (correspondingClass !== v) {
-                setCarrier().correspondingClassField = v
+                setCarrier()
+                correspondingClassField = v
             }
         }
 
@@ -68,7 +69,8 @@ internal class PersistentIrEnumEntry(
                 if (v is PersistentIrBodyBase<*>) {
                     v.container = this
                 }
-                setCarrier().initializerExpressionField = v
+                setCarrier()
+                initializerExpressionField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrField.kt

@@ -66,7 +66,8 @@ internal class PersistentIrField(
                 if (v is PersistentIrBodyBase<*>) {
                     v.container = this
                 }
-                setCarrier().initializerField = v
+                setCarrier()
+                initializerField = v
             }
         }
 
@@ -76,7 +77,8 @@ internal class PersistentIrField(
         get() = getCarrier().correspondingPropertySymbolField
         set(v) {
             if (correspondingPropertySymbol !== v) {
-                setCarrier().correspondingPropertySymbolField = v
+                setCarrier()
+                correspondingPropertySymbolField = v
             }
         }
 
@@ -86,7 +88,8 @@ internal class PersistentIrField(
         get() = getCarrier().metadataField
         set(v) {
             if (metadata !== v) {
-                setCarrier().metadataField = v
+                setCarrier()
+                metadataField = v
             }
         }
 
@@ -96,7 +99,8 @@ internal class PersistentIrField(
         get() = getCarrier().typeField
         set(v) {
             if (type !== v) {
-                setCarrier().typeField = v
+                setCarrier()
+                typeField = v
             }
         }
 
@@ -106,7 +110,8 @@ internal class PersistentIrField(
         get() = getCarrier().isExternalField
         set(v) {
             if (isExternal != v) {
-                setCarrier().isExternalField = v
+                setCarrier()
+                isExternalField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrFunctionCommon.kt

@@ -63,7 +63,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().returnTypeFieldField
         set(v) {
             if (returnTypeField !== v) {
-                setCarrier().returnTypeFieldField = v
+                setCarrier()
+                returnTypeFieldField = v
             }
         }
 
@@ -81,7 +82,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().typeParametersField
         set(v) {
             if (typeParameters !== v) {
-                setCarrier().typeParametersField = v
+                setCarrier()
+                typeParametersField = v
             }
         }
 
@@ -91,7 +93,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().dispatchReceiverParameterField
         set(v) {
             if (dispatchReceiverParameter !== v) {
-                setCarrier().dispatchReceiverParameterField = v
+                setCarrier()
+                dispatchReceiverParameterField = v
             }
         }
 
@@ -101,7 +104,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().extensionReceiverParameterField
         set(v) {
             if (extensionReceiverParameter !== v) {
-                setCarrier().extensionReceiverParameterField = v
+                setCarrier()
+                extensionReceiverParameterField = v
             }
         }
 
@@ -111,7 +115,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().valueParametersField
         set(v) {
             if (valueParameters !== v) {
-                setCarrier().valueParametersField = v
+                setCarrier()
+                valueParametersField = v
             }
         }
 
@@ -124,7 +129,8 @@ internal abstract class PersistentIrFunctionCommon(
                 if (v is PersistentIrBodyBase<*>) {
                     v.container = this
                 }
-                setCarrier().bodyField = v
+                setCarrier()
+                bodyField = v
             }
         }
 
@@ -134,7 +140,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().metadataField
         set(v) {
             if (metadata !== v) {
-                setCarrier().metadataField = v
+                setCarrier()
+                metadataField = v
             }
         }
 
@@ -144,7 +151,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().visibilityField
         set(v) {
             if (visibility !== v) {
-                setCarrier().visibilityField = v
+                setCarrier()
+                visibilityField = v
             }
         }
 
@@ -154,7 +162,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().overriddenSymbolsField
         set(v) {
             if (overriddenSymbols !== v) {
-                setCarrier().overriddenSymbolsField = v
+                setCarrier()
+                overriddenSymbolsField = v
             }
         }
 
@@ -165,7 +174,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().attributeOwnerIdField
         set(v) {
             if (attributeOwnerId !== v) {
-                setCarrier().attributeOwnerIdField = v
+                setCarrier()
+                attributeOwnerIdField = v
             }
         }
 
@@ -175,7 +185,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().correspondingPropertySymbolField
         set(v) {
             if (correspondingPropertySymbol !== v) {
-                setCarrier().correspondingPropertySymbolField = v
+                setCarrier()
+                correspondingPropertySymbolField = v
             }
         }
 
@@ -185,7 +196,8 @@ internal abstract class PersistentIrFunctionCommon(
         get() = getCarrier().isExternalField
         set(v) {
             if (isExternal != v) {
-                setCarrier().isExternalField = v
+                setCarrier()
+                isExternalField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrLocalDelegatedProperty.kt

@@ -60,7 +60,8 @@ internal class PersistentIrLocalDelegatedProperty(
         get() = getCarrier().typeField
         set(v) {
             if (type !== v) {
-                setCarrier().typeField = v
+                setCarrier()
+                typeField = v
             }
         }
 
@@ -70,7 +71,8 @@ internal class PersistentIrLocalDelegatedProperty(
         get() = getCarrier().delegateField!!
         set(v) {
             if (getCarrier().delegateField !== v) {
-                setCarrier().delegateField = v
+                setCarrier()
+                delegateField = v
             }
         }
 
@@ -80,7 +82,8 @@ internal class PersistentIrLocalDelegatedProperty(
         get() = getCarrier().getterField!!
         set(v) {
             if (getCarrier().getterField !== v) {
-                setCarrier().getterField = v
+                setCarrier()
+                getterField = v
             }
         }
 
@@ -90,7 +93,8 @@ internal class PersistentIrLocalDelegatedProperty(
         get() = getCarrier().setterField
         set(v) {
             if (setter !== v) {
-                setCarrier().setterField = v
+                setCarrier()
+                setterField = v
             }
         }
 
@@ -100,7 +104,8 @@ internal class PersistentIrLocalDelegatedProperty(
         get() = getCarrier().metadataField
         set(v) {
             if (metadata !== v) {
-                setCarrier().metadataField = v
+                setCarrier()
+                metadataField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrPropertyCommon.kt

@@ -55,7 +55,8 @@ internal abstract class PersistentIrPropertyCommon(
         get() = getCarrier().backingFieldField
         set(v) {
             if (backingField !== v) {
-                setCarrier().backingFieldField = v
+                setCarrier()
+                backingFieldField = v
             }
         }
 
@@ -65,7 +66,8 @@ internal abstract class PersistentIrPropertyCommon(
         get() = getCarrier().getterField
         set(v) {
             if (getter !== v) {
-                setCarrier().getterField = v
+                setCarrier()
+                getterField = v
             }
         }
 
@@ -75,7 +77,8 @@ internal abstract class PersistentIrPropertyCommon(
         get() = getCarrier().setterField
         set(v) {
             if (setter !== v) {
-                setCarrier().setterField = v
+                setCarrier()
+                setterField = v
             }
         }
 
@@ -85,7 +88,8 @@ internal abstract class PersistentIrPropertyCommon(
         get() = getCarrier().metadataField
         set(v) {
             if (metadata !== v) {
-                setCarrier().metadataField = v
+                setCarrier()
+                metadataField = v
             }
         }
 
@@ -96,7 +100,8 @@ internal abstract class PersistentIrPropertyCommon(
         get() = getCarrier().attributeOwnerIdField
         set(v) {
             if (attributeOwnerId !== v) {
-                setCarrier().attributeOwnerIdField = v
+                setCarrier()
+                attributeOwnerIdField = v
             }
         }
 
@@ -106,7 +111,8 @@ internal abstract class PersistentIrPropertyCommon(
         get() = getCarrier().isExternalField
         set(v) {
             if (isExternal != v) {
-                setCarrier().isExternalField = v
+                setCarrier()
+                isExternalField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrTypeAlias.kt

@@ -59,7 +59,8 @@ internal class PersistentIrTypeAlias(
         get() = getCarrier().typeParametersField
         set(v) {
             if (typeParameters !== v) {
-                setCarrier().typeParametersField = v
+                setCarrier()
+                typeParametersField = v
             }
         }
 
@@ -69,7 +70,8 @@ internal class PersistentIrTypeAlias(
         get() = getCarrier().expandedTypeField
         set(v) {
             if (expandedType !== v) {
-                setCarrier().expandedTypeField = v
+                setCarrier()
+                expandedTypeField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrTypeParameter.kt

@@ -58,7 +58,8 @@ internal class PersistentIrTypeParameter(
         get() = getCarrier().superTypesField
         set(v) {
             if (superTypes !== v) {
-                setCarrier().superTypesField = v
+                setCarrier()
+                superTypesField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrValueParameter.kt

@@ -65,7 +65,8 @@ internal class PersistentIrValueParameter(
                 if (v is PersistentIrBodyBase<*>) {
                     v.container = this
                 }
-                setCarrier().defaultValueField = v
+                setCarrier()
+                defaultValueField = v
             }
         }
 
@@ -75,7 +76,8 @@ internal class PersistentIrValueParameter(
         get() = getCarrier().typeField
         set(v) {
             if (type !== v) {
-                setCarrier().typeField = v
+                setCarrier()
+                typeField = v
             }
         }
 
@@ -85,7 +87,8 @@ internal class PersistentIrValueParameter(
         get() = getCarrier().varargElementTypeField
         set(v) {
             if (varargElementType !== v) {
-                setCarrier().varargElementTypeField = v
+                setCarrier()
+                varargElementTypeField = v
             }
         }
 }

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/AnonymousInitializerCarrier.kt

@@ -13,7 +13,7 @@ import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface AnonymousInitializerCarrier : DeclarationCarrier{
-    var bodyField: IrBlockBody?
+    val bodyField: IrBlockBody?
 
     override fun clone(): AnonymousInitializerCarrier {
         return AnonymousInitializerCarrierImpl(
@@ -28,8 +28,8 @@ internal interface AnonymousInitializerCarrier : DeclarationCarrier{
 
 internal class AnonymousInitializerCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var bodyField: IrBlockBody?
+    override val bodyField: IrBlockBody?
 ) : AnonymousInitializerCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/ClassCarrier.kt

@@ -19,14 +19,14 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface ClassCarrier : DeclarationCarrier{
-    var thisReceiverField: IrValueParameter?
+    val thisReceiverField: IrValueParameter?
-    var metadataField: MetadataSource?
+    val metadataField: MetadataSource?
-    var visibilityField: DescriptorVisibility
+    val visibilityField: DescriptorVisibility
-    var modalityField: Modality
+    val modalityField: Modality
-    var attributeOwnerIdField: IrAttributeContainer
+    val attributeOwnerIdField: IrAttributeContainer
-    var typeParametersField: List<IrTypeParameter>
+    val typeParametersField: List<IrTypeParameter>
-    var superTypesField: List<IrType>
+    val superTypesField: List<IrType>
-    var isExternalField: Boolean
+    val isExternalField: Boolean
 
     override fun clone(): ClassCarrier {
         return ClassCarrierImpl(
@@ -48,15 +48,15 @@ internal interface ClassCarrier : DeclarationCarrier{
 
 internal class ClassCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var thisReceiverField: IrValueParameter?,
+    override val thisReceiverField: IrValueParameter?,
-    override var metadataField: MetadataSource?,
+    override val metadataField: MetadataSource?,
-    override var visibilityField: DescriptorVisibility,
+    override val visibilityField: DescriptorVisibility,
-    override var modalityField: Modality,
+    override val modalityField: Modality,
-    override var attributeOwnerIdField: IrAttributeContainer,
+    override val attributeOwnerIdField: IrAttributeContainer,
-    override var typeParametersField: List<IrTypeParameter>,
+    override val typeParametersField: List<IrTypeParameter>,
-    override var superTypesField: List<IrType>,
+    override val superTypesField: List<IrType>,
-    override var isExternalField: Boolean
+    override val isExternalField: Boolean
 ) : ClassCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/ConstructorCarrier.kt

@@ -18,15 +18,15 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface ConstructorCarrier : DeclarationCarrier{
-    var returnTypeFieldField: IrType
+    val returnTypeFieldField: IrType
-    var dispatchReceiverParameterField: IrValueParameter?
+    val dispatchReceiverParameterField: IrValueParameter?
-    var extensionReceiverParameterField: IrValueParameter?
+    val extensionReceiverParameterField: IrValueParameter?
-    var bodyField: IrBody?
+    val bodyField: IrBody?
-    var metadataField: MetadataSource?
+    val metadataField: MetadataSource?
-    var visibilityField: DescriptorVisibility
+    val visibilityField: DescriptorVisibility
-    var typeParametersField: List<IrTypeParameter>
+    val typeParametersField: List<IrTypeParameter>
-    var valueParametersField: List<IrValueParameter>
+    val valueParametersField: List<IrValueParameter>
-    var isExternalField: Boolean
+    val isExternalField: Boolean
 
     override fun clone(): ConstructorCarrier {
         return ConstructorCarrierImpl(
@@ -49,16 +49,16 @@ internal interface ConstructorCarrier : DeclarationCarrier{
 
 internal class ConstructorCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var returnTypeFieldField: IrType,
+    override val returnTypeFieldField: IrType,
-    override var dispatchReceiverParameterField: IrValueParameter?,
+    override val dispatchReceiverParameterField: IrValueParameter?,
-    override var extensionReceiverParameterField: IrValueParameter?,
+    override val extensionReceiverParameterField: IrValueParameter?,
-    override var bodyField: IrBody?,
+    override val bodyField: IrBody?,
-    override var metadataField: MetadataSource?,
+    override val metadataField: MetadataSource?,
-    override var visibilityField: DescriptorVisibility,
+    override val visibilityField: DescriptorVisibility,
-    override var typeParametersField: List<IrTypeParameter>,
+    override val typeParametersField: List<IrTypeParameter>,
-    override var valueParametersField: List<IrValueParameter>,
+    override val valueParametersField: List<IrValueParameter>,
-    override var isExternalField: Boolean
+    override val isExternalField: Boolean
 ) : ConstructorCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/EnumEntryCarrier.kt

@@ -14,8 +14,8 @@ import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface EnumEntryCarrier : DeclarationCarrier{
-    var correspondingClassField: IrClass?
+    val correspondingClassField: IrClass?
-    var initializerExpressionField: IrExpressionBody?
+    val initializerExpressionField: IrExpressionBody?
 
     override fun clone(): EnumEntryCarrier {
         return EnumEntryCarrierImpl(
@@ -31,9 +31,9 @@ internal interface EnumEntryCarrier : DeclarationCarrier{
 
 internal class EnumEntryCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var correspondingClassField: IrClass?,
+    override val correspondingClassField: IrClass?,
-    override var initializerExpressionField: IrExpressionBody?
+    override val initializerExpressionField: IrExpressionBody?
 ) : EnumEntryCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/ErrorDeclarationCarrier.kt

@@ -25,7 +25,7 @@ internal interface ErrorDeclarationCarrier : DeclarationCarrier{
 
 internal class ErrorDeclarationCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>
+    override val annotationsField: List<IrConstructorCall>
 ) : ErrorDeclarationCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/FieldCarrier.kt

@@ -16,11 +16,11 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface FieldCarrier : DeclarationCarrier{
-    var typeField: IrType
+    val typeField: IrType
-    var initializerField: IrExpressionBody?
+    val initializerField: IrExpressionBody?
-    var correspondingPropertySymbolField: IrPropertySymbol?
+    val correspondingPropertySymbolField: IrPropertySymbol?
-    var metadataField: MetadataSource?
+    val metadataField: MetadataSource?
-    var isExternalField: Boolean
+    val isExternalField: Boolean
 
     override fun clone(): FieldCarrier {
         return FieldCarrierImpl(
@@ -39,12 +39,12 @@ internal interface FieldCarrier : DeclarationCarrier{
 
 internal class FieldCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var typeField: IrType,
+    override val typeField: IrType,
-    override var initializerField: IrExpressionBody?,
+    override val initializerField: IrExpressionBody?,
-    override var correspondingPropertySymbolField: IrPropertySymbol?,
+    override val correspondingPropertySymbolField: IrPropertySymbol?,
-    override var metadataField: MetadataSource?,
+    override val metadataField: MetadataSource?,
-    override var isExternalField: Boolean
+    override val isExternalField: Boolean
 ) : FieldCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/FunctionCarrier.kt

@@ -21,18 +21,18 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface FunctionCarrier : DeclarationCarrier{
-    var returnTypeFieldField: IrType
+    val returnTypeFieldField: IrType
-    var dispatchReceiverParameterField: IrValueParameter?
+    val dispatchReceiverParameterField: IrValueParameter?
-    var extensionReceiverParameterField: IrValueParameter?
+    val extensionReceiverParameterField: IrValueParameter?
-    var bodyField: IrBody?
+    val bodyField: IrBody?
-    var metadataField: MetadataSource?
+    val metadataField: MetadataSource?
-    var visibilityField: DescriptorVisibility
+    val visibilityField: DescriptorVisibility
-    var typeParametersField: List<IrTypeParameter>
+    val typeParametersField: List<IrTypeParameter>
-    var valueParametersField: List<IrValueParameter>
+    val valueParametersField: List<IrValueParameter>
-    var correspondingPropertySymbolField: IrPropertySymbol?
+    val correspondingPropertySymbolField: IrPropertySymbol?
-    var overriddenSymbolsField: List<IrSimpleFunctionSymbol>
+    val overriddenSymbolsField: List<IrSimpleFunctionSymbol>
-    var attributeOwnerIdField: IrAttributeContainer
+    val attributeOwnerIdField: IrAttributeContainer
-    var isExternalField: Boolean
+    val isExternalField: Boolean
 
     override fun clone(): FunctionCarrier {
         return FunctionCarrierImpl(
@@ -58,19 +58,19 @@ internal interface FunctionCarrier : DeclarationCarrier{
 
 internal class FunctionCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var returnTypeFieldField: IrType,
+    override val returnTypeFieldField: IrType,
-    override var dispatchReceiverParameterField: IrValueParameter?,
+    override val dispatchReceiverParameterField: IrValueParameter?,
-    override var extensionReceiverParameterField: IrValueParameter?,
+    override val extensionReceiverParameterField: IrValueParameter?,
-    override var bodyField: IrBody?,
+    override val bodyField: IrBody?,
-    override var metadataField: MetadataSource?,
+    override val metadataField: MetadataSource?,
-    override var visibilityField: DescriptorVisibility,
+    override val visibilityField: DescriptorVisibility,
-    override var typeParametersField: List<IrTypeParameter>,
+    override val typeParametersField: List<IrTypeParameter>,
-    override var valueParametersField: List<IrValueParameter>,
+    override val valueParametersField: List<IrValueParameter>,
-    override var correspondingPropertySymbolField: IrPropertySymbol?,
+    override val correspondingPropertySymbolField: IrPropertySymbol?,
-    override var overriddenSymbolsField: List<IrSimpleFunctionSymbol>,
+    override val overriddenSymbolsField: List<IrSimpleFunctionSymbol>,
-    override var attributeOwnerIdField: IrAttributeContainer,
+    override val attributeOwnerIdField: IrAttributeContainer,
-    override var isExternalField: Boolean
+    override val isExternalField: Boolean
 ) : FunctionCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/LocalDelegatedPropertyCarrier.kt

@@ -16,11 +16,11 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface LocalDelegatedPropertyCarrier : DeclarationCarrier{
-    var typeField: IrType
+    val typeField: IrType
-    var delegateField: IrVariable?
+    val delegateField: IrVariable?
-    var getterField: IrSimpleFunction?
+    val getterField: IrSimpleFunction?
-    var setterField: IrSimpleFunction?
+    val setterField: IrSimpleFunction?
-    var metadataField: MetadataSource?
+    val metadataField: MetadataSource?
 
     override fun clone(): LocalDelegatedPropertyCarrier {
         return LocalDelegatedPropertyCarrierImpl(
@@ -39,12 +39,12 @@ internal interface LocalDelegatedPropertyCarrier : DeclarationCarrier{
 
 internal class LocalDelegatedPropertyCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var typeField: IrType,
+    override val typeField: IrType,
-    override var delegateField: IrVariable?,
+    override val delegateField: IrVariable?,
-    override var getterField: IrSimpleFunction?,
+    override val getterField: IrSimpleFunction?,
-    override var setterField: IrSimpleFunction?,
+    override val setterField: IrSimpleFunction?,
-    override var metadataField: MetadataSource?
+    override val metadataField: MetadataSource?
 ) : LocalDelegatedPropertyCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/PropertyCarrier.kt

@@ -16,12 +16,12 @@ import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface PropertyCarrier : DeclarationCarrier{
-    var backingFieldField: IrField?
+    val backingFieldField: IrField?
-    var getterField: IrSimpleFunction?
+    val getterField: IrSimpleFunction?
-    var setterField: IrSimpleFunction?
+    val setterField: IrSimpleFunction?
-    var metadataField: MetadataSource?
+    val metadataField: MetadataSource?
-    var attributeOwnerIdField: IrAttributeContainer
+    val attributeOwnerIdField: IrAttributeContainer
-    var isExternalField: Boolean
+    val isExternalField: Boolean
 
     override fun clone(): PropertyCarrier {
         return PropertyCarrierImpl(
@@ -41,13 +41,13 @@ internal interface PropertyCarrier : DeclarationCarrier{
 
 internal class PropertyCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var backingFieldField: IrField?,
+    override val backingFieldField: IrField?,
-    override var getterField: IrSimpleFunction?,
+    override val getterField: IrSimpleFunction?,
-    override var setterField: IrSimpleFunction?,
+    override val setterField: IrSimpleFunction?,
-    override var metadataField: MetadataSource?,
+    override val metadataField: MetadataSource?,
-    override var attributeOwnerIdField: IrAttributeContainer,
+    override val attributeOwnerIdField: IrAttributeContainer,
-    override var isExternalField: Boolean
+    override val isExternalField: Boolean
 ) : PropertyCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/TypeAliasCarrier.kt

@@ -14,8 +14,8 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface TypeAliasCarrier : DeclarationCarrier{
-    var typeParametersField: List<IrTypeParameter>
+    val typeParametersField: List<IrTypeParameter>
-    var expandedTypeField: IrType
+    val expandedTypeField: IrType
 
     override fun clone(): TypeAliasCarrier {
         return TypeAliasCarrierImpl(
@@ -31,9 +31,9 @@ internal interface TypeAliasCarrier : DeclarationCarrier{
 
 internal class TypeAliasCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var typeParametersField: List<IrTypeParameter>,
+    override val typeParametersField: List<IrTypeParameter>,
-    override var expandedTypeField: IrType
+    override val expandedTypeField: IrType
 ) : TypeAliasCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/TypeParameterCarrier.kt

@@ -13,7 +13,7 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface TypeParameterCarrier : DeclarationCarrier{
-    var superTypesField: List<IrType>
+    val superTypesField: List<IrType>
 
     override fun clone(): TypeParameterCarrier {
         return TypeParameterCarrierImpl(
@@ -28,8 +28,8 @@ internal interface TypeParameterCarrier : DeclarationCarrier{
 
 internal class TypeParameterCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var superTypesField: List<IrType>
+    override val superTypesField: List<IrType>
 ) : TypeParameterCarrier

compiler/ir/ir.tree.persistent/gen/org/jetbrains/kotlin/ir/declarations/persistent/carriers/ValueParameterCarrier.kt

@@ -14,9 +14,9 @@ import org.jetbrains.kotlin.ir.types.IrType
 // Auto-generated by compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt. DO NOT EDIT!
 
 internal interface ValueParameterCarrier : DeclarationCarrier{
-    var defaultValueField: IrExpressionBody?
+    val defaultValueField: IrExpressionBody?
-    var typeField: IrType
+    val typeField: IrType
-    var varargElementTypeField: IrType?
+    val varargElementTypeField: IrType?
 
     override fun clone(): ValueParameterCarrier {
         return ValueParameterCarrierImpl(
@@ -33,10 +33,10 @@ internal interface ValueParameterCarrier : DeclarationCarrier{
 
 internal class ValueParameterCarrierImpl(
     override val lastModified: Int,
-    override var parentField: IrDeclarationParent?,
+    override val parentField: IrDeclarationParent?,
-    override var originField: IrDeclarationOrigin,
+    override val originField: IrDeclarationOrigin,
-    override var annotationsField: List<IrConstructorCall>,
+    override val annotationsField: List<IrConstructorCall>,
-    override var defaultValueField: IrExpressionBody?,
+    override val defaultValueField: IrExpressionBody?,
-    override var typeField: IrType,
+    override val typeField: IrType,
-    override var varargElementTypeField: IrType?
+    override val varargElementTypeField: IrType?
 ) : ValueParameterCarrier

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/PersistentIrGenerator.kt

@@ -143,7 +143,8 @@ internal object PersistentIrGenerator {
                             +"v.container = this"
                         ),
                         id
-                    ) else id) + "setCarrier().${name}Field = v"
+                    ) else id) + "setCarrier()",
+                    +"${name}Field = v"
                 )
             )
         ).indent()
@@ -161,7 +162,7 @@ internal object PersistentIrGenerator {
     fun carriers(name: String, vararg fields: Field): E = lines(
         id,
         +"internal interface ${name}Carrier : DeclarationCarrier" + block(
-            *(fields.map { +"var ${it.name}Field: " + it.type + if (it.lateinit) "?" else "" }.toTypedArray()),
+            *(fields.map { +"val ${it.name}Field: " + it.type + if (it.lateinit) "?" else "" }.toTypedArray()),
             id,
             +"override fun clone(): ${name}Carrier " + block(
                 +"return ${name}CarrierImpl(",
@@ -179,10 +180,10 @@ internal object PersistentIrGenerator {
         +"internal class ${name}CarrierImpl(",
         arrayOf(
             +"override val lastModified: Int",
-            +"override var parentField: " + IrDeclarationParent + "?",
+            +"override val parentField: " + IrDeclarationParent + "?",
-            +"override var originField: " + IrDeclarationOrigin,
+            +"override val originField: " + IrDeclarationOrigin,
-            +"override var annotationsField: List<" + IrConstructorCall + ">",
+            +"override val annotationsField: List<" + IrConstructorCall + ">",
-            *(fields.map { +"override var ${it.name}Field: " + it.type + if (it.lateinit) "?" else "" }.toTypedArray()),
+            *(fields.map { +"override val ${it.name}Field: " + it.type + if (it.lateinit) "?" else "" }.toTypedArray()),
         ).join(separator = ",\n").indent(),
         +") : ${name}Carrier",
         id,

compiler/ir/ir.tree.persistent/src/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrDeclarationBase.kt

@@ -17,12 +17,20 @@ import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 interface PersistentIrDeclarationBase<T : DeclarationCarrier> : PersistentIrElementBase<T>, IrDeclaration, DeclarationCarrier {
     var removedOn: Int
 
+
+    override var parentField: IrDeclarationParent?
+
+    override var originField: IrDeclarationOrigin
+
+    override var annotationsField: List<IrConstructorCall>
+
     // TODO reduce boilerplate
     override var parent: IrDeclarationParent
         get() = getCarrier().parentField ?: throw UninitializedPropertyAccessException("Parent not initialized: $this")
         set(p) {
             if (getCarrier().parentField !== p) {
-                setCarrier().parentField = p
+                setCarrier()
+                parentField = p
             }
         }
 
@@ -30,7 +38,8 @@ interface PersistentIrDeclarationBase<T : DeclarationCarrier> : PersistentIrElem
         get() = getCarrier().originField
         set(p) {
             if (getCarrier().originField !== p) {
-                setCarrier().originField = p
+                setCarrier()
+                originField = p
             }
         }
 
@@ -38,7 +47,8 @@ interface PersistentIrDeclarationBase<T : DeclarationCarrier> : PersistentIrElem
         get() = getCarrier().annotationsField
         set(v) {
             if (getCarrier().annotationsField !== v) {
-                setCarrier().annotationsField = v
+                setCarrier()
+                annotationsField = v
             }
         }
 
@@ -96,7 +106,7 @@ interface PersistentIrElementBase<T : Carrier> : IrElement, Carrier {
 
     // TODO naming? e.g. `mutableCarrier`
     @Suppress("UNCHECKED_CAST")
-    fun setCarrier(): T {
+    fun setCarrier() {
         val stage = factory.stageController.currentStage
 
         ensureLowered()
@@ -111,14 +121,12 @@ interface PersistentIrElementBase<T : Carrier> : IrElement, Carrier {
 
         // TODO move up? i.e. fast path
         if (stage == lastModified) {
-            return this as T
+            return
         } else {
             values = (values ?: emptyArray()) + this.clone() as T
         }
 
         this.lastModified = stage
-
-        return this as T
     }
 }
 
@@ -131,7 +139,8 @@ interface PersistentIrBodyBase<B : PersistentIrBodyBase<B>> : PersistentIrElemen
         get() = getCarrier().containerField!!
         set(p) {
             if (getCarrier().containerField !== p) {
-                setCarrier().containerField = p
+                setCarrier()
+                containerField = p
             }
         }
 

compiler/ir/ir.tree.persistent/src/org/jetbrains/kotlin/ir/declarations/persistent/carriers/DeclarationCarrier.kt

@@ -10,7 +10,7 @@ import org.jetbrains.kotlin.ir.declarations.IrDeclarationParent
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 
 interface DeclarationCarrier : Carrier {
-    var parentField: IrDeclarationParent?
+    val parentField: IrDeclarationParent?
-    var originField: IrDeclarationOrigin
+    val originField: IrDeclarationOrigin
-    var annotationsField: List<IrConstructorCall>
+    val annotationsField: List<IrConstructorCall>
 }