[FIR/IR generator] Move usedTypes to AbstractElement, rename it

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

@@ -22,7 +22,6 @@ fun Implementation.generateCode(generationPath: File): GeneratedFile =
         this.typeName,
         fileSuppressions = listOf("DuplicatedCode", "unused"),
     ) {
-        addAllImports(usedTypes)
         ImplementationPrinter(this).printImplementation(this@generateCode)
     }
 

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

@@ -208,7 +208,7 @@ object IrTree : AbstractTreeBuilder() {
         +field("isCrossinline", boolean)
         +field("isNoinline", boolean)
         +field("isHidden", boolean) {
-            usedTypes.add(idSignatureType)
+            additionalImports.add(idSignatureType)
             kDoc = """
             If `true`, the value parameter does not participate in [IdSignature] computation.
 
@@ -487,7 +487,7 @@ object IrTree : AbstractTreeBuilder() {
         +field("name", type<Name>(), mutable = false)
         +field("irBuiltins", type(Packages.tree, "IrBuiltIns"), mutable = false)
         +listField("files", file, mutability = MutableList)
-        usedTypes += ArbitraryImportable(Packages.tree, "UNDEFINED_OFFSET")
+        additionalImports += ArbitraryImportable(Packages.tree, "UNDEFINED_OFFSET")
         +field("startOffset", int, mutable = false) {
             baseGetter = "UNDEFINED_OFFSET"
         }
@@ -722,8 +722,8 @@ object IrTree : AbstractTreeBuilder() {
             visibility = Visibility.PROTECTED
         }
 
-        usedTypes += ArbitraryImportable(Packages.exprs, "checkArgumentSlotAccess")
         generationCallback = {
+            addImport(ArbitraryImportable(Packages.exprs, "checkArgumentSlotAccess"))
             val indexParam = FunctionParameter("index", StandardTypes.int)
             val valueArgumentParam = FunctionParameter("valueArgument", expression.copy(nullable = true))
             val typeArgumentParam = FunctionParameter("type", irTypeType.copy(nullable = true))

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

@@ -124,8 +124,6 @@ class Element(
 
     override var kDoc: String? = null
 
-    val usedTypes = mutableListOf<Importable>()
-
     override fun toString() = name
 
     operator fun TypeVariable.unaryPlus() = apply {

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

@@ -137,7 +137,6 @@ private class ElementPrinter(printer: SmartPrinter) : AbstractElementPrinter<Ele
 
 fun printElements(generationPath: File, model: Model) = model.elements.map { element ->
     printGeneratedType(generationPath, TREE_GENERATOR_README, element.packageName, element.typeName) {
-        addAllImports(element.usedTypes)
         ElementPrinter(this).printElement(element)
     }
 }

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

@@ -166,6 +166,15 @@ abstract class AbstractElement<Element, Field, Implementation>(
         }
     }
 
+    /**
+     * Types/functions that you want to additionally import in the file with the element class.
+     *
+     * This is useful if, for example, default values of fields reference classes or functions from other packages.
+     *
+     * Note that classes referenced in field types will be imported automatically.
+     */
+    val additionalImports = mutableListOf<Importable>()
+
     final override fun get(fieldName: String): Field? {
         return allFields.firstOrNull { it.name == fieldName }
     }

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

@@ -31,6 +31,7 @@ abstract class AbstractElementPrinter<Element : AbstractElement<Element, Field,
 
     context(ImportCollector)
     fun printElement(element: Element) {
+        addAllImports(element.additionalImports)
         printer.run {
             val kind = element.kind ?: error("Expected non-null element kind")
 

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

@@ -42,7 +42,14 @@ abstract class AbstractImplementation<Implementation, Element, Field>(
 
     override val packageName = element.packageName + ".impl"
 
-    val usedTypes = mutableListOf<Importable>()
+    /**
+     * Types/functions that you want to additionally import in the file with the implementation class.
+     *
+     * This is useful if, for example, default values of fields reference classes or functions from other packages.
+     *
+     * Note that classes referenced in field types will be imported automatically.
+     */
+    val additionalImports = mutableListOf<Importable>()
 
     init {
         @Suppress("UNCHECKED_CAST")

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

@@ -32,6 +32,7 @@ abstract class AbstractImplementationPrinter<Implementation, Element, Implementa
 
     context(ImportCollector)
     fun printImplementation(implementation: Implementation) {
+        addAllImports(implementation.additionalImports)
         printer.run {
             buildSet {
                 if (implementation.requiresOptIn) {

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

@@ -156,7 +156,7 @@ abstract class AbstractImplementationConfigurator<Implementation, Element, Imple
          * Note that classes referenced in field types will be imported automatically.
          */
         fun additionalImports(vararg importables: Importable) {
-            importables.forEach { implementation.usedTypes += it }
+            implementation.additionalImports.addAll(importables)
         }
 
         /**