[FIR generator] Specify Field.isChild in base tree configuration

instead of inside implementation configuration.

Whether a field is a child element is a core concept of the tree,
not a matter of particular implementation class.

It is especially visible in IR tree, where the base classes implement the
acceptChildren method. It will also be more relevant in the future.

This also aligns the config style between IR and FIR tree generators.

^KT-65773 In Progress

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

@@ -66,10 +66,6 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
                 delegateCall = "shortName()"
                 withGetter = true
             }
-
-            default("delegate") {
-                isChild = false
-            }
         }
 
         fun ImplementationContext.commonAnnotationConfig() {
@@ -87,16 +83,10 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
 
         impl(annotationCall) {
             commonAnnotationConfig()
-            default("argumentMapping") {
-                isChild = false
-            }
         }
 
         impl(errorAnnotationCall) {
             commonAnnotationConfig()
-            default("argumentMapping") {
-                isChild = false
-            }
             default("annotationResolvePhase") {
                 value = "FirAnnotationResolvePhase.Types"
             }
@@ -512,9 +502,6 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
 
         impl(resolvedTypeRef) {
             publicImplementation()
-            default("delegatedTypeRef") {
-                isChild = false
-            }
         }
 
         impl(errorExpression) {

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

@@ -528,7 +528,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
         }
 
         resolvedImport.configure {
-            +field("delegate", import)
+            +field("delegate", import, isChild = false)
             +field("packageFqName", fqNameType)
             +field("relativeParentClassName", fqNameType, nullable = true)
             +field("resolvedParentClassId", classIdType, nullable = true)
@@ -547,7 +547,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
         }
 
         annotationCall.configure {
-            +field("argumentMapping", annotationArgumentMapping, withReplace = true)
+            +field("argumentMapping", annotationArgumentMapping, withReplace = true, isChild = false)
             +field("annotationResolvePhase", annotationResolvePhaseType, withReplace = true)
             +field("containingDeclarationSymbol", firBasedSymbolType.withArgs(TypeRef.Star)).apply {
                 withBindThis = false
@@ -555,7 +555,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
         }
 
         errorAnnotationCall.configure {
-            +field("argumentMapping", annotationArgumentMapping, withReplace = true)
+            +field("argumentMapping", annotationArgumentMapping, withReplace = true, isChild = false)
         }
 
         annotationArgumentMapping.configure {
@@ -721,7 +721,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
 
         resolvedTypeRef.configure {
             +field("type", coneKotlinTypeType)
-            +field("delegatedTypeRef", typeRef, nullable = true)
+            +field("delegatedTypeRef", typeRef, nullable = true, isChild = false)
             element.otherParents.add(typeRefMarkerType)
         }
 

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

@@ -10,11 +10,11 @@ import org.jetbrains.kotlin.generators.tree.*
 // ----------- Simple field -----------
 
 fun field(name: String, type: TypeRefWithNullability, nullable: Boolean = false, withReplace: Boolean = false): Field {
-    return SimpleField(name, type.copy(nullable), withReplace)
+    return SimpleField(name, type.copy(nullable), withReplace = withReplace)
 }
 
 fun field(type: ClassRef<*>, nullable: Boolean = false, withReplace: Boolean = false): Field {
-    return SimpleField(type.simpleName.replaceFirstChar(Char::lowercaseChar), type.copy(nullable), withReplace)
+    return SimpleField(type.simpleName.replaceFirstChar(Char::lowercaseChar), type.copy(nullable), withReplace = withReplace)
 }
 
 fun booleanField(name: String, withReplace: Boolean = false): Field {
@@ -31,22 +31,23 @@ fun intField(name: String, withReplace: Boolean = false): Field {
 
 // ----------- Fir field -----------
 
-fun field(name: String, element: ElementOrRef, nullable: Boolean = false, withReplace: Boolean = false): Field {
-    return FirField(name, element.copy(nullable), withReplace)
+fun field(name: String, element: ElementOrRef, nullable: Boolean = false, withReplace: Boolean = false, isChild: Boolean = true): Field {
+    return FirField(name, element.copy(nullable), withReplace = withReplace, isChild = isChild)
 }
 
-fun field(element: Element, nullable: Boolean = false, withReplace: Boolean = false): Field {
-    return FirField(element.name.replaceFirstChar(Char::lowercaseChar), element.copy(nullable), withReplace)
+fun field(element: Element, nullable: Boolean = false, withReplace: Boolean = false, isChild: Boolean = true): Field {
+    return FirField(element.name.replaceFirstChar(Char::lowercaseChar), element.copy(nullable), withReplace = withReplace, isChild = isChild)
 }
 
 // ----------- Field list -----------
 
-fun fieldList(name: String, type: TypeRef, withReplace: Boolean = false, useMutableOrEmpty: Boolean = false): Field {
-    return FieldList(name, type, withReplace, useMutableOrEmpty)
+fun fieldList(name: String, type: TypeRef, withReplace: Boolean = false, useMutableOrEmpty: Boolean = false, isChild: Boolean = true): Field {
+    return FieldList(name, type, withReplace = withReplace, isChild = isChild, useMutableOrEmpty = useMutableOrEmpty)
 }
 
-fun fieldList(elementOrRef: ElementOrRef, withReplace: Boolean = false, useMutableOrEmpty: Boolean = false): Field {
-    return FieldList(elementOrRef.element.name.replaceFirstChar(Char::lowercaseChar) + "s", elementOrRef, withReplace, useMutableOrEmpty)
+fun fieldList(elementOrRef: ElementOrRef, withReplace: Boolean = false, useMutableOrEmpty: Boolean = false, isChild: Boolean = true): Field {
+    val name = elementOrRef.element.name.replaceFirstChar(Char::lowercaseChar) + "s"
+    return FieldList(name, elementOrRef, withReplace = withReplace, isChild = isChild, useMutableOrEmpty = useMutableOrEmpty)
 }
 
 // ----------- Field set -----------

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

@@ -71,6 +71,8 @@ class FieldWithDefault(override val origin: Field) : Field(), AbstractFieldWithD
     override var withReplace: Boolean
         get() = origin.withReplace
         set(_) {}
+    override val isChild: Boolean
+        get() = origin.isChild
     override val containsElement: Boolean
         get() = origin.containsElement
     override var needsSeparateTransform: Boolean
@@ -127,7 +129,6 @@ class FieldWithDefault(override val origin: Field) : Field(), AbstractFieldWithD
             it.isMutable = isMutable
             it.withGetter = withGetter
             it.fromDelegate = fromDelegate
-            it.isChild = isChild
         }
     }
 }
@@ -143,6 +144,9 @@ class SimpleField(
 ) : Field() {
     override var isMutable: Boolean = withReplace
 
+    override val isChild: Boolean
+        get() = false
+
     override fun internalCopy(): Field {
         return SimpleField(
             name = name,
@@ -175,6 +179,7 @@ class FirField(
     override val name: String,
     val element: ElementRef,
     override var withReplace: Boolean,
+    override val isChild: Boolean,
 ) : Field() {
 
     override val typeRef: ElementRef
@@ -190,7 +195,8 @@ class FirField(
         return FirField(
             name,
             element,
-            withReplace
+            withReplace,
+            isChild,
         ).apply {
             withBindThis = this@FirField.withBindThis
         }
@@ -203,7 +209,8 @@ class FieldList(
     override val name: String,
     override val baseType: TypeRef,
     override var withReplace: Boolean,
-    useMutableOrEmpty: Boolean = false
+    override val isChild: Boolean,
+    useMutableOrEmpty: Boolean = false,
 ) : Field(), ListField {
     override var defaultValueInImplementation: String? = null
 
@@ -225,6 +232,7 @@ class FieldList(
             name,
             baseType,
             withReplace,
+            isChild,
             isMutableOrEmptyList
         )
     }

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

@@ -78,8 +78,7 @@ abstract class AbstractTreeBuilder {
         isChild: Boolean = true,
         initializer: SingleField.() -> Unit = {}
     ): SingleField {
-        return SingleField(name, type.copy(nullable), mutable).apply {
-            this.isChild = isChild
+        return SingleField(name, type.copy(nullable), mutable, isChild).apply {
             initializer()
         }
     }
@@ -103,8 +102,8 @@ abstract class AbstractTreeBuilder {
             listType = listType,
             isNullable = nullable,
             mutable = mutability == ListField.Mutability.Var,
+            isChild = isChild,
         ).apply(initializer).apply {
-            this.isChild = isChild
             initializer()
         }
     }

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

@@ -73,12 +73,13 @@ class SingleField(
     name: String,
     override var typeRef: TypeRefWithNullability,
     mutable: Boolean,
+    override val isChild: Boolean,
 ) : Field(name, mutable) {
 
     override fun replaceType(newType: TypeRefWithNullability) =
-        SingleField(name, newType, isMutable).also(::updateFieldsInCopy)
+        SingleField(name, newType, isMutable, isChild).also(::updateFieldsInCopy)
 
-    override fun internalCopy() = SingleField(name, typeRef, isMutable)
+    override fun internalCopy() = SingleField(name, typeRef, isMutable, isChild)
 }
 
 class ListField(
@@ -87,6 +88,7 @@ class ListField(
     private val isNullable: Boolean,
     override val listType: ClassRef<PositionTypeParameterRef>,
     mutable: Boolean,
+    override val isChild: Boolean,
 ) : Field(name, mutable), AbstractListField {
 
     override val typeRef: ClassRef<PositionTypeParameterRef>
@@ -94,7 +96,7 @@ class ListField(
 
     override fun replaceType(newType: TypeRefWithNullability) = copy()
 
-    override fun internalCopy() = ListField(name, baseType, isNullable, listType, isMutable)
+    override fun internalCopy() = ListField(name, baseType, isNullable, listType, isMutable, isChild)
 
     enum class Mutability {
         Var,