IR tree gen: restore strict cast in IrProperty.transformChildren

compiler/ir/ir.tree/gen/org/jetbrains/kotlin/ir/declarations/IrProperty.kt

@@ -55,7 +55,7 @@ abstract class IrProperty : IrDeclarationBase(), IrPossiblyExternalDeclaration,
 
     override fun <D> transformChildren(transformer: IrElementTransformer<D>, data: D) {
         backingField = backingField?.transform(transformer, data) as? IrField
-        getter = getter?.transform(transformer, data) as? IrSimpleFunction
-        setter = setter?.transform(transformer, data) as? IrSimpleFunction
+        getter = getter?.transform(transformer, data) as IrSimpleFunction?
+        setter = setter?.transform(transformer, data) as IrSimpleFunction?
     }
 }

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/IrTree.kt

@@ -380,8 +380,12 @@ object IrTree : AbstractTreeBuilder() {
         +field("isExpect", boolean)
         +field("isFakeOverride", boolean)
         +field("backingField", field, mutable = true, nullable = true, isChild = true)
-        +field("getter", simpleFunction, mutable = true, nullable = true, isChild = true)
-        +field("setter", simpleFunction, mutable = true, nullable = true, isChild = true)
+        +field("getter", simpleFunction, mutable = true, nullable = true, isChild = true) {
+            strictCastInTransformChildren = true
+        }
+        +field("setter", simpleFunction, mutable = true, nullable = true, isChild = true) {
+            strictCastInTransformChildren = true
+        }
     }
 
     //TODO: make IrScript as IrPackageFragment, because script is used as a file, not as a class

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/config/ConfigModel.kt

@@ -87,6 +87,7 @@ sealed class FieldConfig(
     var baseDefaultValue: CodeBlock? = null
     var baseGetter: CodeBlock? = null
     var printProperty = true
+    var strictCastInTransformChildren = false
 
     var generationCallback: (PropertySpec.Builder.() -> Unit)? = null
 

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/model/Model.kt

@@ -74,6 +74,7 @@ sealed class Field(
     val nullable: Boolean,
     val mutable: Boolean,
     val isChild: Boolean,
+    val strictCastInTransformChildren: Boolean,
 ) {
     abstract val type: TypeRef
     abstract val baseDefaultValue: CodeBlock?
@@ -95,9 +96,10 @@ class SingleField(
     nullable: Boolean,
     mutable: Boolean,
     isChild: Boolean,
+    strictCastInTransformChildren: Boolean,
     override val baseDefaultValue: CodeBlock?,
     override val baseGetter: CodeBlock?,
-) : Field(config, name, nullable, mutable, isChild) {
+) : Field(config, name, nullable, mutable, isChild, strictCastInTransformChildren) {
     override val transformable: Boolean
         get() = mutable
 }
@@ -110,10 +112,11 @@ class ListField(
     nullable: Boolean,
     mutable: Boolean,
     isChild: Boolean,
+    strictCastInTransformChildren: Boolean,
     override val transformable: Boolean,
     override val baseDefaultValue: CodeBlock?,
     override val baseGetter: CodeBlock?,
-) : Field(config, name, nullable, mutable, isChild) {
+) : Field(config, name, nullable, mutable, isChild, strictCastInTransformChildren) {
     override val type: TypeRef
         get() = listType.withArgs(elementType)
 }

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/model/Transformations.kt

@@ -28,6 +28,7 @@ fun config2model(config: Config): Model {
                     fc.nullable,
                     fc.mutable,
                     fc.isChild,
+                    fc.strictCastInTransformChildren,
                     fc.baseDefaultValue,
                     fc.baseGetter
                 )
@@ -44,6 +45,7 @@ fun config2model(config: Config): Model {
                         fc.nullable,
                         fc.mutability == ListFieldConfig.Mutability.Var,
                         fc.isChild,
+                        fc.strictCastInTransformChildren,
                         fc.mutability != ListFieldConfig.Mutability.Immutable,
                         fc.baseDefaultValue,
                         fc.baseGetter

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/print/Elements.kt

@@ -158,8 +158,13 @@ fun printElements(generationPath: File, model: Model) = sequence {
                                 val elRef = child.type as ElementRef
                                 if (!elRef.element.transform) {
                                     append(" as")
-                                    if (child.nullable) append("?")
-                                    append(" %T")
+                                    if (child.strictCastInTransformChildren) {
+                                        append(" %T")
+                                        if (child.nullable) append("?")
+                                    } else {
+                                        if (child.nullable) append("?")
+                                        append(" %T")
+                                    }
                                     args.add(elRef.toPoet())
                                 }
                             }