[FIR/IR generator] Make AbstractField generic over itself

This will make some code more type-safe.

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/model/Builder.kt

@@ -9,7 +9,7 @@ import org.jetbrains.kotlin.generators.tree.*
 
 private const val DEFAULT_BUILDER_PACKAGE = "org.jetbrains.kotlin.fir.tree.builder"
 
-sealed class Builder : FieldContainer, TypeRef, Importable {
+sealed class Builder : FieldContainer<FieldWithDefault>, TypeRef, Importable {
     val parents: MutableList<IntermediateBuilder> = mutableListOf()
     val usedTypes: MutableList<Importable> = mutableListOf()
     abstract override val allFields: List<FieldWithDefault>

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

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.fir.tree.generator.model
 
 import org.jetbrains.kotlin.generators.tree.*
 
-sealed class Field : AbstractField() {
+sealed class Field : AbstractField<Field>() {
     open var withReplace: Boolean = false
 
     open var needsSeparateTransform: Boolean = false

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/model/Implementation.kt

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.fir.tree.generator.model
 
 import org.jetbrains.kotlin.generators.tree.*
 
-class Implementation(val element: Element, val name: String?) : FieldContainer, ImplementationKindOwner {
+class Implementation(val element: Element, val name: String?) : FieldContainer<FieldWithDefault>, ImplementationKindOwner {
     override val allParents: List<ImplementationKindOwner> get() = listOf(element)
     val isDefault = name == null
     override val typeName = name ?: (element.typeName + "Impl")

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/printer/implementation.kt

@@ -159,7 +159,6 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
                     println()
                     withIndent {
                         for (field in walkableFields) {
-                            check(field is FieldWithDefault)
                             when (field.name) {
                                 "explicitReceiver" -> {
                                     val explicitReceiver = implementation["explicitReceiver"]!!
@@ -226,7 +225,6 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
                 if (!isInterface && !isAbstract) {
                     printBlock {
                         for (field in transformableChildren) {
-                            check(field is FieldWithDefault)
                             when {
                                 field.name == "explicitReceiver" -> {
                                     val explicitReceiver = implementation["explicitReceiver"]!!

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

@@ -163,7 +163,7 @@ sealed class Field(
     override val name: String,
     override var isMutable: Boolean,
     val isChild: Boolean,
-) : AbstractField() {
+) : AbstractField<Field>() {
     var baseDefaultValue: String? = null
     var baseGetter: String? = null
 

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractElement.kt

@@ -10,9 +10,9 @@ package org.jetbrains.kotlin.generators.tree
  */
 abstract class AbstractElement<Element, Field>(
     val name: String,
-) : ElementOrRef<Element, Field>, FieldContainer, ImplementationKindOwner
+) : ElementOrRef<Element, Field>, FieldContainer<Field>, ImplementationKindOwner
         where Element : AbstractElement<Element, Field>,
-              Field : AbstractField {
+              Field : AbstractField<Field> {
 
     /**
      * The fully-qualified name of the property in the tree generator that is used to configure this element.

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractElementPrinter.kt

@@ -13,7 +13,7 @@ import org.jetbrains.kotlin.utils.withIndent
 /**
  * A common class for printing FIR or IR tree elements.
  */
-abstract class AbstractElementPrinter<Element : AbstractElement<Element, Field>, Field : AbstractField>(
+abstract class AbstractElementPrinter<Element : AbstractElement<Element, Field>, Field : AbstractField<Field>>(
     private val printer: SmartPrinter,
 ) {
 

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractField.kt

@@ -5,7 +5,7 @@
 
 package org.jetbrains.kotlin.generators.tree
 
-abstract class AbstractField {
+abstract class AbstractField<Field : AbstractField<Field>> {
 
     abstract val name: String
 
@@ -66,7 +66,7 @@ abstract class AbstractField {
         if (this === other) return true
         if (other == null) return false
         if (javaClass != other.javaClass) return false
-        other as AbstractField
+        other as AbstractField<*>
         return name == other.name
     }
 

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractFieldPrinter.kt

@@ -11,7 +11,7 @@ import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import org.jetbrains.kotlin.utils.SmartPrinter
 import org.jetbrains.kotlin.utils.withIndent
 
-abstract class AbstractFieldPrinter<Field : AbstractField>(
+abstract class AbstractFieldPrinter<Field : AbstractField<Field>>(
     private val printer: SmartPrinter,
 ) {
 

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractVisitorPrinter.kt

@@ -11,7 +11,7 @@ import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.utils.SmartPrinter
 import org.jetbrains.kotlin.utils.withIndent
 
-abstract class AbstractVisitorPrinter<Element : AbstractElement<Element, Field>, Field : AbstractField>(
+abstract class AbstractVisitorPrinter<Element : AbstractElement<Element, Field>, Field : AbstractField<Field>>(
     val printer: SmartPrinter,
 ) {
 

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractVisitorVoidPrinter.kt

@@ -13,7 +13,7 @@ abstract class AbstractVisitorVoidPrinter<Element, Field>(
     printer: SmartPrinter,
 ) : AbstractVisitorPrinter<Element, Field>(printer)
         where Element : AbstractElement<Element, Field>,
-              Field : AbstractField {
+              Field : AbstractField<Field> {
 
     final override val visitorTypeParameters: List<TypeVariable>
         get() = emptyList()

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/FieldContainer.kt

@@ -5,9 +5,9 @@
 
 package org.jetbrains.kotlin.generators.tree
 
-interface FieldContainer {
+interface FieldContainer<out Field : AbstractField<*>> {
-    val allFields: List<AbstractField>
+    val allFields: List<Field>
-    operator fun get(fieldName: String): AbstractField?
+    operator fun get(fieldName: String): Field?
 
     val hasAcceptMethod: Boolean
         get() = false
@@ -24,12 +24,12 @@ interface FieldContainer {
     /**
      * The fields on which to run the visitor in generated `acceptChildren` methods.
      */
-    val walkableChildren: List<AbstractField>
+    val walkableChildren: List<Field>
         get() = allFields.filter { it.containsElement && !it.withGetter && it.needAcceptAndTransform }
 
     /**
      * The fields on which to run the transformer in generated `transformChildren` methods.
      */
-    val transformableChildren: List<AbstractField>
+    val transformableChildren: List<Field>
         get() = walkableChildren.filter { it.isMutable || it is ListField }
 }

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/TypeRef.kt

@@ -130,13 +130,13 @@ data class TypeRefWithVariance<out T : TypeRef>(val variance: Variance, val type
 
 interface ElementOrRef<Element, Field> : ParametrizedTypeRef<ElementOrRef<Element, Field>, NamedTypeParameterRef>, ClassOrElementRef
         where Element : AbstractElement<Element, Field>,
-              Field : AbstractField {
+              Field : AbstractField<Field> {
     val element: Element
 
     override fun copy(nullable: Boolean): ElementRef<Element, Field>
 }
 
-data class ElementRef<Element : AbstractElement<Element, Field>, Field : AbstractField>(
+data class ElementRef<Element : AbstractElement<Element, Field>, Field : AbstractField<Field>>(
     override val element: Element,
     override val args: Map<NamedTypeParameterRef, TypeRef> = emptyMap(),
     override val nullable: Boolean = false,

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/printer/printUtils.kt

@@ -280,7 +280,7 @@ fun SmartPrinter.printTransformMethod(
 
 context(ImportCollector)
 fun SmartPrinter.printAcceptChildrenMethod(
-    element: FieldContainer,
+    element: FieldContainer<*>,
     visitorClass: ClassRef<PositionTypeParameterRef>,
     visitorResultType: TypeRef,
     modality: Modality? = null,
@@ -315,7 +315,7 @@ fun SmartPrinter.printAcceptChildrenMethod(
 
 context(ImportCollector)
 fun SmartPrinter.printTransformChildrenMethod(
-    element: FieldContainer,
+    element: FieldContainer<*>,
     transformerClass: ClassRef<PositionTypeParameterRef>,
     returnType: TypeRef,
     modality: Modality? = null,