[FIR] Add special node for sealed classes

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

@@ -43,6 +43,7 @@ object FirTreeBuilder : AbstractFirTreeBuilder() {
     val klass = element("Class", Declaration, declaration, statement, annotationContainer)
     val classLikeDeclaration = element("ClassLikeDeclaration", Declaration, statement, memberDeclaration, symbolOwner, typeParametersOwner)
     val regularClass = element("RegularClass", Declaration, namedDeclaration, classLikeDeclaration, klass)
+    val sealedClass = element("SealedClass", Declaration, regularClass)
     val typeAlias = element("TypeAlias", Declaration, classLikeDeclaration)
     val enumEntry = element("EnumEntry", Declaration, regularClass)
 

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

@@ -61,12 +61,20 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
             kind = Interface
         }
 
-        impl(regularClass, "FirClassImpl") {
+        val modifiableRegularClass = impl(regularClass, "FirModifiableRegularClass") {
             parents += modifiableClass
             parents += modifiableTypeParametersOwner
+            kind = Interface
+        }
+
+        val regularClassConfig: ImplementationContext.() -> Unit = {
+            parents += modifiableRegularClass
             defaultNull("companionObject")
             defaultSupertypesComputationStatus()
         }
+        impl(regularClass, "FirClassImpl", regularClassConfig)
+
+        impl(sealedClass, config = regularClassConfig)
 
         impl(anonymousObject) {
             parents += modifiableClass

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

@@ -220,6 +220,10 @@ object NodeConfigurator : AbstractFieldConfigurator() {
             +superTypeRefs(withReplace = true)
         }
 
+        sealedClass.configure {
+            +fieldList("inheritors", classIdType, withReplace = true)
+        }
+
         typeAlias.configure {
             parentArg(classLikeDeclaration, "F", typeAlias)
             +symbol("FirTypeAliasSymbol")

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

@@ -289,7 +289,7 @@ fun PrintWriter.printImplementation(implementation: Implementation) {
             }
         }
 
-        element.allFields.filter { it.type.contains("Symbol") }
+        element.allFields.filter { it.type.contains("Symbol") && it !is FieldList }
             .takeIf { it.isNotEmpty() && !isInterface && !element.type.contains("Reference")}
             ?.let { symbolFields ->
                 indent(1)
@@ -338,7 +338,7 @@ fun PrintWriter.printImplementation(implementation: Implementation) {
                         }
 
                         else -> {
-                            if (type == "FirClassImpl" && field.name == "declarations") {
+                            if (type in setOf("FirClassImpl", "FirSealedClassImpl") && field.name == "declarations") {
                                 indent(2)
                                 println("(declarations.firstOrNull { it is FirConstructorImpl } as? FirConstructorImpl)?.typeParameters?.forEach { it.accept(visitor, data) }")
                             }
@@ -413,7 +413,7 @@ fun PrintWriter.printImplementation(implementation: Implementation) {
                     }
                     field.name in setOf("dispatchReceiver", "extensionReceiver") -> {
                     }
-                    type == "FirClassImpl" && field.name == "declarations" -> {
+                    type in setOf("FirClassImpl", "FirSealedClassImpl") && field.name == "declarations" -> {
                         indent(2)
                         println("(declarations.firstOrNull { it is FirConstructorImpl } as? FirConstructorImpl)?.typeParameters?.transformInplace(transformer, data)")
                         indent(2)

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

@@ -58,4 +58,5 @@ val compositeTransformResultType = type("fir.visitors", "CompositeTransformResul
 
 val abstractFirBasedSymbolType = type("fir.symbols", "AbstractFirBasedSymbol")
 val backingFieldSymbolType = type("fir.symbols.impl", "FirBackingFieldSymbol")
-val delegateFieldSymbolType = type("fir.symbols.impl", "FirDelegateFieldSymbol")
+val delegateFieldSymbolType = type("fir.symbols.impl", "FirDelegateFieldSymbol")
+val classSymbolType = type("fir.symbols.impl", "FirClassSymbol")