[IR] Pass null instead of IrUninitializedType to IrFactory

#KT-66053 In progress

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

@@ -405,7 +405,9 @@ object IrTree : AbstractTreeBuilder() {
         // NB: there's an inline constructor for Array and each primitive array class.
         +field("isInline", boolean)
         +field("isExpect", boolean)
-        +field("returnType", irTypeType)
+        +field("returnType", irTypeType) {
+            useFieldInIrFactory(customType = irTypeType.copy(nullable = true))
+        }
         +field("dispatchReceiverParameter", valueParameter, nullable = true)
         +field("extensionReceiverParameter", valueParameter, nullable = true)
         +listField("valueParameters", valueParameter, mutability = Var)

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -25,8 +25,8 @@ abstract class AbstractTreeBuilder {
         customUseInIrFactoryStrategy = Field.UseFieldAsParameterInIrFactoryStrategy.No
     }
 
-    protected fun Field.useFieldInIrFactory(defaultValue: String? = null) {
-        customUseInIrFactoryStrategy = Field.UseFieldAsParameterInIrFactoryStrategy.Yes(defaultValue)
+    protected fun Field.useFieldInIrFactory(customType: TypeRef? = null, defaultValue: String? = null) {
+        customUseInIrFactoryStrategy = Field.UseFieldAsParameterInIrFactoryStrategy.Yes(customType, defaultValue)
     }
 
     fun element(category: Element.Category, name: String? = null, initializer: Element.() -> Unit = {}): ElementDelegate {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -16,7 +16,7 @@ sealed class Field(
 
         data object No : UseFieldAsParameterInIrFactoryStrategy()
 
-        data class Yes(val defaultValue: String?) : UseFieldAsParameterInIrFactoryStrategy()
+        data class Yes(val customType: TypeRef?, val defaultValue: String?) : UseFieldAsParameterInIrFactoryStrategy()
     }
 
     var customUseInIrFactoryStrategy: UseFieldAsParameterInIrFactoryStrategy? = null
@@ -26,7 +26,7 @@ sealed class Field(
             ?: if (isChild && containsElement) {
                 UseFieldAsParameterInIrFactoryStrategy.No
             } else {
-                UseFieldAsParameterInIrFactoryStrategy.Yes(null)
+                UseFieldAsParameterInIrFactoryStrategy.Yes(null, null)
             }
 
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -50,7 +50,7 @@ private class FactoryMethod(val element: Element) {
         .filterNot { it.name in element.fieldsToSkipInIrFactoryMethod }
         .mapNotNull { field ->
             (field.useInIrFactoryStrategy as? Field.UseFieldAsParameterInIrFactoryStrategy.Yes)?.let {
-                FunctionParameter(field.name, field.typeRef, it.defaultValue)
+                FunctionParameter(field.name, it.customType ?: field.typeRef, it.defaultValue)
             }
         }
         .sortedBy { it.defaultValue != null } // All parameters with default values must go last