[FIR generator] Factor out element printer to common module

This is a step towards commonizing the code generator between
FIR and IR: KT-61970

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/contracts/impl/FirContractElementDeclarationImpl.kt

@@ -20,6 +20,7 @@ internal class FirContractElementDeclarationImpl(
     override val source: KtSourceElement?,
     override val effect: ConeContractDescriptionElement,
 ) : FirContractElementDeclaration() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirContractElementDeclarationImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/contracts/impl/FirEffectDeclarationImpl.kt

@@ -20,6 +20,7 @@ internal class FirEffectDeclarationImpl(
     override val source: KtSourceElement?,
     override val effect: ConeEffectDeclaration,
 ) : FirEffectDeclaration() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirEffectDeclarationImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/contracts/impl/FirLegacyRawContractDescriptionImpl.kt

@@ -22,6 +22,7 @@ internal class FirLegacyRawContractDescriptionImpl(
     override var contractCall: FirFunctionCall,
     override val diagnostic: ConeDiagnostic?,
 ) : FirLegacyRawContractDescription() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         contractCall.accept(visitor, data)
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/contracts/impl/FirRawContractDescriptionImpl.kt

@@ -21,6 +21,7 @@ internal class FirRawContractDescriptionImpl(
     override val source: KtSourceElement?,
     override val rawEffects: MutableList<FirExpression>,
 ) : FirRawContractDescription() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         rawEffects.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/contracts/impl/FirResolvedContractDescriptionImpl.kt

@@ -25,6 +25,7 @@ internal class FirResolvedContractDescriptionImpl(
     override val unresolvedEffects: MutableList<FirContractElementDeclaration>,
     override val diagnostic: ConeDiagnostic?,
 ) : FirResolvedContractDescription() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         effects.forEach { it.accept(visitor, data) }
         unresolvedEffects.forEach { it.accept(visitor, data) }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirAnonymousFunctionImpl.kt

@@ -57,6 +57,7 @@ internal class FirAnonymousFunctionImpl(
     override val typeParameters: MutableList<FirTypeParameter>,
     override var typeRef: FirTypeRef,
 ) : FirAnonymousFunction() {
+
     init {
         symbol.bind(this)
         resolveState = resolvePhase.asResolveState()

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirBackingFieldImpl.kt

@@ -55,6 +55,7 @@ open class FirBackingFieldImpl @FirImplementationDetail constructor(
     override val typeParameters: MutableList<FirTypeParameter>,
     override var status: FirDeclarationStatus,
 ) : FirBackingField() {
+
     init {
         symbol.bind(this)
         resolveState = resolvePhase.asResolveState()

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirCodeFragmentImpl.kt

@@ -33,6 +33,7 @@ internal class FirCodeFragmentImpl(
     override val symbol: FirCodeFragmentSymbol,
     override var block: FirBlock,
 ) : FirCodeFragment() {
+
     init {
         symbol.bind(this)
         resolveState = resolvePhase.asResolveState()

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirConstructedClassTypeParameterRefImpl.kt

@@ -20,6 +20,7 @@ internal class FirConstructedClassTypeParameterRefImpl(
     override val source: KtSourceElement?,
     override val symbol: FirTypeParameterSymbol,
 ) : FirConstructedClassTypeParameterRef() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirConstructedClassTypeParameterRefImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirContextReceiverImpl.kt

@@ -23,6 +23,7 @@ internal class FirContextReceiverImpl(
     override val customLabelName: Name?,
     override val labelNameFromTypeRef: Name?,
 ) : FirContextReceiver() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         typeRef.accept(visitor, data)
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirDanglingModifierListImpl.kt

@@ -33,6 +33,7 @@ internal class FirDanglingModifierListImpl(
     override val diagnostic: ConeDiagnostic,
     override val symbol: FirDanglingModifierSymbol,
 ) : FirDanglingModifierList() {
+
     init {
         symbol.bind(this)
         resolveState = resolvePhase.asResolveState()

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirImportImpl.kt

@@ -24,6 +24,7 @@ internal class FirImportImpl(
     override val aliasName: Name?,
     override val aliasSource: KtSourceElement?,
 ) : FirImport() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirImportImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirOuterClassTypeParameterRefImpl.kt

@@ -21,6 +21,7 @@ class FirOuterClassTypeParameterRefImpl @FirImplementationDetail constructor(
     override val source: KtSourceElement?,
     override val symbol: FirTypeParameterSymbol,
 ) : FirOuterClassTypeParameterRef() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirOuterClassTypeParameterRefImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirReceiverParameterImpl.kt

@@ -25,6 +25,7 @@ internal class FirReceiverParameterImpl(
     override var typeRef: FirTypeRef,
     override var annotations: MutableOrEmptyList<FirAnnotation>,
 ) : FirReceiverParameter() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         typeRef.accept(visitor, data)
         annotations.forEach { it.accept(visitor, data) }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirScriptImpl.kt

@@ -38,6 +38,7 @@ internal class FirScriptImpl(
     override var contextReceivers: MutableOrEmptyList<FirContextReceiver>,
     override val resultPropertyName: Name?,
 ) : FirScript() {
+
     init {
         symbol.bind(this)
         resolveState = resolvePhase.asResolveState()

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirTypeAliasImpl.kt

@@ -38,6 +38,7 @@ internal class FirTypeAliasImpl(
     override var expandedTypeRef: FirTypeRef,
     override var annotations: MutableOrEmptyList<FirAnnotation>,
 ) : FirTypeAlias() {
+
     init {
         symbol.bind(this)
         resolveState = resolvePhase.asResolveState()

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirTypeParameterImpl.kt

@@ -40,6 +40,7 @@ internal class FirTypeParameterImpl(
     override val bounds: MutableList<FirTypeRef>,
     override var annotations: MutableOrEmptyList<FirAnnotation>,
 ) : FirTypeParameter() {
+
     init {
         symbol.bind(this)
         resolveState = resolvePhase.asResolveState()

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirArrayLiteralImpl.kt

@@ -30,6 +30,7 @@ internal class FirArrayLiteralImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override var argumentList: FirArgumentList,
 ) : FirArrayLiteral() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         argumentList.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirAssignmentOperatorStatementImpl.kt

@@ -28,6 +28,7 @@ internal class FirAssignmentOperatorStatementImpl(
     override var leftArgument: FirExpression,
     override var rightArgument: FirExpression,
 ) : FirAssignmentOperatorStatement() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         leftArgument.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirAugmentedArraySetCallImpl.kt

@@ -28,6 +28,7 @@ internal class FirAugmentedArraySetCallImpl(
     override var calleeReference: FirReference,
     override val arrayAccessSource: KtSourceElement?,
 ) : FirAugmentedArraySetCall() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         lhsGetCall.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirBinaryLogicExpressionImpl.kt

@@ -33,6 +33,7 @@ internal class FirBinaryLogicExpressionImpl(
     override var rightOperand: FirExpression,
     override val kind: LogicOperationKind,
 ) : FirBinaryLogicExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         leftOperand.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirBlockImpl.kt

@@ -30,6 +30,7 @@ internal class FirBlockImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override val statements: MutableList<FirStatement>,
 ) : FirBlock() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         statements.forEach { it.accept(visitor, data) }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirCallableReferenceAccessImpl.kt

@@ -42,6 +42,7 @@ internal class FirCallableReferenceAccessImpl(
     override var calleeReference: FirNamedReference,
     override var hasQuestionMarkAtLHS: Boolean,
 ) : FirCallableReferenceAccess() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         contextReceiverArguments.forEach { it.accept(visitor, data) }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirCatchImpl.kt

@@ -22,6 +22,7 @@ internal class FirCatchImpl(
     override var parameter: FirProperty,
     override var block: FirBlock,
 ) : FirCatch() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         parameter.accept(visitor, data)
         block.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirCheckNotNullCallImpl.kt

@@ -32,6 +32,7 @@ internal class FirCheckNotNullCallImpl(
     override var argumentList: FirArgumentList,
     override var calleeReference: FirReference,
 ) : FirCheckNotNullCall() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         argumentList.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirCheckedSafeCallSubjectImpl.kt

@@ -31,6 +31,7 @@ internal class FirCheckedSafeCallSubjectImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override val originalReceiverRef: FirExpressionRef<FirExpression>,
 ) : FirCheckedSafeCallSubject() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirClassReferenceExpressionImpl.kt

@@ -30,6 +30,7 @@ internal class FirClassReferenceExpressionImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override var classTypeRef: FirTypeRef,
 ) : FirClassReferenceExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         classTypeRef.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirConstExpressionImpl.kt

@@ -31,6 +31,7 @@ internal class FirConstExpressionImpl<T> (
     override var kind: ConstantValueKind<T>,
     override val value: T,
 ) : FirConstExpression<T>() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirDesugaredAssignmentValueReferenceExpressionImpl.kt

@@ -31,6 +31,7 @@ internal class FirDesugaredAssignmentValueReferenceExpressionImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override val expressionRef: FirExpressionRef<FirExpression>,
 ) : FirDesugaredAssignmentValueReferenceExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirDoWhileLoopImpl.kt

@@ -29,6 +29,7 @@ internal class FirDoWhileLoopImpl(
     override var condition: FirExpression,
     override var label: FirLabel?,
 ) : FirDoWhileLoop() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         block.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirElvisExpressionImpl.kt

@@ -33,6 +33,7 @@ internal class FirElvisExpressionImpl(
     override var lhs: FirExpression,
     override var rhs: FirExpression,
 ) : FirElvisExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         calleeReference.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirExpressionStub.kt

@@ -29,6 +29,7 @@ class FirExpressionStub @FirImplementationDetail constructor(
     override var coneTypeOrNull: ConeKotlinType?,
     override var annotations: MutableOrEmptyList<FirAnnotation>,
 ) : FirExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirFunctionCallImpl.kt

@@ -40,6 +40,7 @@ open class FirFunctionCallImpl @FirImplementationDetail constructor(
     override var calleeReference: FirNamedReference,
     override val origin: FirFunctionCallOrigin,
 ) : FirFunctionCall() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         contextReceiverArguments.forEach { it.accept(visitor, data) }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirInaccessibleReceiverExpressionImpl.kt

@@ -31,6 +31,7 @@ internal class FirInaccessibleReceiverExpressionImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override var calleeReference: FirThisReference,
 ) : FirInaccessibleReceiverExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         calleeReference.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirIncrementDecrementExpressionImpl.kt

@@ -34,6 +34,7 @@ internal class FirIncrementDecrementExpressionImpl(
     override var expression: FirExpression,
     override val operationSource: KtSourceElement?,
 ) : FirIncrementDecrementExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         expression.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirIntegerLiteralOperatorCallImpl.kt

@@ -40,6 +40,7 @@ internal class FirIntegerLiteralOperatorCallImpl(
     override var dispatchReceiver: FirExpression?,
     override var extensionReceiver: FirExpression?,
 ) : FirIntegerLiteralOperatorCall() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         contextReceiverArguments.forEach { it.accept(visitor, data) }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirPropertyAccessExpressionImpl.kt

@@ -40,6 +40,7 @@ class FirPropertyAccessExpressionImpl @FirImplementationDetail constructor(
     override var source: KtSourceElement?,
     override var nonFatalDiagnostics: MutableOrEmptyList<ConeDiagnostic>,
 ) : FirPropertyAccessExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         calleeReference.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirResolvedReifiedParameterReferenceImpl.kt

@@ -30,6 +30,7 @@ internal class FirResolvedReifiedParameterReferenceImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override val symbol: FirTypeParameterSymbol,
 ) : FirResolvedReifiedParameterReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirSafeCallExpressionImpl.kt

@@ -30,6 +30,7 @@ internal class FirSafeCallExpressionImpl(
     override val checkedSubjectRef: FirExpressionRef<FirCheckedSafeCallSubject>,
     override var selector: FirStatement,
 ) : FirSafeCallExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         receiver.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirTryExpressionImpl.kt

@@ -31,6 +31,7 @@ internal class FirTryExpressionImpl(
     override val catches: MutableList<FirCatch>,
     override var finallyBlock: FirBlock?,
 ) : FirTryExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         calleeReference.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirVarargArgumentsExpressionImpl.kt

@@ -32,6 +32,7 @@ internal class FirVarargArgumentsExpressionImpl(
     override val arguments: MutableList<FirExpression>,
     override var varargElementType: FirTypeRef,
 ) : FirVarargArgumentsExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         arguments.forEach { it.accept(visitor, data) }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirVariableAssignmentImpl.kt

@@ -26,6 +26,7 @@ internal class FirVariableAssignmentImpl(
     override var lValue: FirExpression,
     override var rValue: FirExpression,
 ) : FirVariableAssignment() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         lValue.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirWhenBranchImpl.kt

@@ -22,6 +22,7 @@ internal class FirWhenBranchImpl(
     override var condition: FirExpression,
     override var result: FirBlock,
 ) : FirWhenBranch() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         condition.accept(visitor, data)
         result.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirWhenExpressionImpl.kt

@@ -34,6 +34,7 @@ internal class FirWhenExpressionImpl(
     override var exhaustivenessStatus: ExhaustivenessStatus?,
     override val usedAsExpression: Boolean,
 ) : FirWhenExpression() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         calleeReference.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirWhileLoopImpl.kt

@@ -29,6 +29,7 @@ internal class FirWhileLoopImpl(
     override var condition: FirExpression,
     override var block: FirBlock,
 ) : FirWhileLoop() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         label?.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/impl/FirFileAnnotationsContainerImpl.kt

@@ -32,6 +32,7 @@ internal class FirFileAnnotationsContainerImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override val containingFileSymbol: FirFileSymbol,
 ) : FirFileAnnotationsContainer() {
+
     init {
         resolveState = resolvePhase.asResolveState()
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/impl/FirFunctionTypeParameterImpl.kt

@@ -22,6 +22,7 @@ internal class FirFunctionTypeParameterImpl(
     override val name: Name?,
     override var returnTypeRef: FirTypeRef,
 ) : FirFunctionTypeParameter() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         returnTypeRef.accept(visitor, data)
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/impl/FirLabelImpl.kt

@@ -19,6 +19,7 @@ internal class FirLabelImpl(
     override val source: KtSourceElement?,
     override val name: String,
 ) : FirLabel() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirLabelImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/impl/FirPackageDirectiveImpl.kt

@@ -20,6 +20,7 @@ internal class FirPackageDirectiveImpl(
     override val source: KtSourceElement?,
     override val packageFqName: FqName,
 ) : FirPackageDirective() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirPackageDirectiveImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirExplicitSuperReference.kt

@@ -21,6 +21,7 @@ internal class FirExplicitSuperReference(
     override val labelName: String?,
     override var superTypeRef: FirTypeRef,
 ) : FirSuperReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         superTypeRef.accept(visitor, data)
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirFromMissingDependenciesNamedReferenceImpl.kt

@@ -20,6 +20,7 @@ internal class FirFromMissingDependenciesNamedReferenceImpl(
     override val source: KtSourceElement?,
     override val name: Name,
 ) : FirFromMissingDependenciesNamedReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirFromMissingDependenciesNamedReferenceImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirPropertyFromParameterResolvedNamedReference.kt

@@ -23,6 +23,7 @@ class FirPropertyFromParameterResolvedNamedReference @FirImplementationDetail co
     override val name: Name,
     override val resolvedSymbol: FirBasedSymbol<*>,
 ) : FirResolvedNamedReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirPropertyFromParameterResolvedNamedReference {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirResolvedCallableReferenceImpl.kt

@@ -26,6 +26,7 @@ internal class FirResolvedCallableReferenceImpl(
     override val inferredTypeArguments: MutableList<ConeKotlinType>,
     override val mappedArguments: CallableReferenceMappedArguments,
 ) : FirResolvedCallableReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirResolvedCallableReferenceImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirResolvedErrorReferenceImpl.kt

@@ -24,6 +24,7 @@ internal class FirResolvedErrorReferenceImpl(
     override val resolvedSymbol: FirBasedSymbol<*>,
     override val diagnostic: ConeDiagnostic,
 ) : FirResolvedErrorReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirResolvedErrorReferenceImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirResolvedNamedReferenceImpl.kt

@@ -22,6 +22,7 @@ internal class FirResolvedNamedReferenceImpl(
     override val name: Name,
     override val resolvedSymbol: FirBasedSymbol<*>,
 ) : FirResolvedNamedReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirResolvedNamedReferenceImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirSimpleNamedReference.kt

@@ -21,6 +21,7 @@ class FirSimpleNamedReference @FirImplementationDetail constructor(
     override val source: KtSourceElement?,
     override val name: Name,
 ) : FirNamedReference() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirSimpleNamedReference {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/types/impl/FirDynamicTypeRefImpl.kt

@@ -24,6 +24,7 @@ internal class FirDynamicTypeRefImpl(
     override var annotations: MutableOrEmptyList<FirAnnotation>,
     override val isMarkedNullable: Boolean,
 ) : FirDynamicTypeRef() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/types/impl/FirFunctionTypeRefImpl.kt

@@ -31,6 +31,7 @@ internal class FirFunctionTypeRefImpl(
     override val isSuspend: Boolean,
     override val contextReceiverTypeRefs: MutableList<FirTypeRef>,
 ) : FirFunctionTypeRef() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         receiverTypeRef?.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/types/impl/FirIntersectionTypeRefImpl.kt

@@ -27,6 +27,7 @@ internal class FirIntersectionTypeRefImpl(
     override var leftType: FirTypeRef,
     override var rightType: FirTypeRef,
 ) : FirIntersectionTypeRef() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
         leftType.accept(visitor, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/types/impl/FirPlaceholderProjectionImpl.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.fir.visitors.FirVisitor
 internal class FirPlaceholderProjectionImpl(
     override val source: KtSourceElement?,
 ) : FirPlaceholderProjection() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirPlaceholderProjectionImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/types/impl/FirResolvedTypeRefImpl.kt

@@ -28,6 +28,7 @@ class FirResolvedTypeRefImpl @FirImplementationDetail constructor(
     override val type: ConeKotlinType,
     override var delegatedTypeRef: FirTypeRef?,
 ) : FirResolvedTypeRef() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         annotations.forEach { it.accept(visitor, data) }
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/types/impl/FirStarProjectionImpl.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.fir.visitors.FirVisitor
 internal class FirStarProjectionImpl(
     override val source: KtSourceElement?,
 ) : FirStarProjection() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirStarProjectionImpl {

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/types/impl/FirTypeProjectionWithVarianceImpl.kt

@@ -22,6 +22,7 @@ internal class FirTypeProjectionWithVarianceImpl(
     override var typeRef: FirTypeRef,
     override val variance: Variance,
 ) : FirTypeProjectionWithVariance() {
+
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         typeRef.accept(visitor, data)
     }

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

@@ -77,7 +77,7 @@ class Element(override val name: String, override val propertyName: String, kind
         get() = emptyList() // Use Implementation#transformableChildren instead
 
     var baseTransformerType: Element? = null
-    val transformerType: Element get() = baseTransformerType ?: this
+    val transformerClass: Element get() = baseTransformerType ?: this
 
     override val visitFunctionName: String
         get() = "visit$name"

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

@@ -13,140 +13,81 @@ import org.jetbrains.kotlin.fir.tree.generator.util.get
 import org.jetbrains.kotlin.generators.tree.*
 import org.jetbrains.kotlin.generators.tree.printer.*
 import org.jetbrains.kotlin.utils.SmartPrinter
-import org.jetbrains.kotlin.utils.withIndent
 import java.io.File
 
-fun Element.generateCode(generationPath: File): GeneratedFile =
-    printGeneratedType(generationPath, TREE_GENERATOR_README, packageName, this.typeName) {
-        println()
-        printElement(this@generateCode)
-    }
+private class ElementPrinter(printer: SmartPrinter) : AbstractElementPrinter<Element, Field>(printer) {
 
-private class ElementFieldPrinter(printer: SmartPrinter) : AbstractFieldPrinter<Field>(printer)
+    override fun makeFieldPrinter(printer: SmartPrinter) = object : AbstractFieldPrinter<Field>(printer) {}
 
-context(ImportCollector)
-fun SmartPrinter.printElement(element: Element) {
-    with(element) {
-        val isInterface = kind == ImplementationKind.Interface || kind == ImplementationKind.SealedInterface
-        fun abstract() {
-            if (!isInterface) {
-                print("abstract ")
-            }
-        }
+    context(ImportCollector)
+    override fun SmartPrinter.printAdditionalMethods(element: Element) {
+        val kind = element.kind ?: error("Expected non-null element kind")
+        with(element) {
+            // TODO: Add a kDoc for `accept`
+            printAcceptMethod(element, firVisitorType, hasImplementation = true, kDoc = null)
 
-        fun override() {
-            if (!isRootElement) {
-                print("override ")
-            }
-        }
-
-        printKDoc(element.extendedKDoc())
-        print("${kind!!.title} $typeName")
-        print(params.typeParameters())
-        val parentRefs = element.parentRefs
-        if (parentRefs.isNotEmpty()) {
-            print(
-                parentRefs.sortedBy { it.typeKind }.joinToString(prefix = " : ") { parent ->
-                    parent.render() + parent.inheritanceClauseParenthesis()
-                }
+            // TODO: Add a kDoc for `transform`
+            printTransformMethod(
+                element = element,
+                transformerClass = firTransformerType,
+                implementation = "transformer.transform${element.name}(this, data)",
+                returnType = TypeVariable("E", listOf(AbstractFirTreeBuilder.baseFirElement)),
+                kDoc = null,
             )
-        }
-        print(params.multipleUpperBoundsList())
-        println(" {")
-        withIndent {
-            val fieldPrinter = ElementFieldPrinter(this@printElement)
-            allFields.forEach { field ->
-                if (field.isFinal && field.fromParent || field.isParameter) return@forEach
-                fieldPrinter.printField(field, override = field.fromParent) {
-                    if (!field.isFinal) {
-                        abstract()
-                    }
-                }
-            }
-
-            if (hasAcceptMethod) {
-                if (allFields.isNotEmpty()) {
-                    println()
-                }
-
-                override()
-                println("fun <R, D> accept(visitor: ${firVisitorType.render()}<R, D>, data: D): R =")
-                withIndent {
-                    println("visitor.visit${element.name}(this, data)")
-                }
-            }
-
-            if (hasTransformMethod) {
-                println()
-                println("@Suppress(\"UNCHECKED_CAST\")")
-                override()
-                println(
-                    "fun <E : ",
-                    AbstractFirTreeBuilder.baseFirElement.render(),
-                    ", D> transform(transformer: ",
-                    firTransformerType.render(),
-                    "<D>, data: D): E ="
-                )
-                withIndent {
-                    println("transformer.transform$name(this, data) as E")
-                }
-            }
 
             fun Field.replaceDeclaration(override: Boolean, overridenType: TypeRefWithNullability? = null, forceNullable: Boolean = false) {
                 println()
                 if (name == "source") {
-                    println("@${firImplementationDetailType.render()}")
+                    println("@", firImplementationDetailType.render())
                 }
-                abstract()
-                if (override) print("override ")
-                println(replaceFunctionDeclaration(overridenType, forceNullable))
+                replaceFunctionDeclaration(this, override, kind, overridenType, forceNullable)
+                println()
             }
 
             allFields.filter { it.withReplace }.forEach {
-                val override = overridenFields[it, it] &&
-                        !(it.name == "source" && element == FirTreeBuilder.qualifiedAccessExpression)
+                val override = overridenFields[it, it] && !(it.name == "source" && element == FirTreeBuilder.qualifiedAccessExpression)
                 it.replaceDeclaration(override, forceNullable = it.useNullableForReplace)
-                for (overridenType in it.overridenTypes) {
-                    it.replaceDeclaration(true, overridenType)
+                for (overriddenType in it.overridenTypes) {
+                    it.replaceDeclaration(true, overriddenType)
                 }
             }
 
             for (field in allFields) {
                 if (!field.needsSeparateTransform) continue
                 println()
-                abstract()
-                if (field.fromParent && field.parentHasSeparateTransform) {
-                    print("override ")
-                }
-                println(field.transformFunctionDeclaration(element))
+                transformFunctionDeclaration(field, element, override = field.fromParent && field.parentHasSeparateTransform, kind)
+                println()
             }
             if (needTransformOtherChildren) {
                 println()
-                abstract()
-                if (element.elementParents.any { it.element.needTransformOtherChildren }) {
-                    print("override ")
-                }
-                println(transformFunctionDeclaration("OtherChildren", element))
+                transformOtherChildrenFunctionDeclaration(
+                    element,
+                    override = element.elementParents.any { it.element.needTransformOtherChildren },
+                    kind,
+                )
+                println()
             }
 
             if (element.isRootElement) {
-                require(isInterface) {
-                    "$element must be an interface"
-                }
                 println()
-                println("fun accept(visitor: ${firVisitorVoidType.render()}) = accept(visitor, null)")
-                if (element.hasAcceptChildrenMethod) {
-                    println()
-                    println("fun <R, D> acceptChildren(visitor: ${firVisitorType.render()}<R, D>, data: D)")
-                }
+                println("fun accept(visitor: ", firVisitorVoidType.render(), ") = accept(visitor, null)")
+
+                // TODO: Add a kDoc for `acceptChildren`
+                printAcceptChildrenMethod(element, firVisitorType, visitorResultType = TypeVariable("R"), kDoc = null)
+                println()
+                println()
+                println("fun acceptChildren(visitor: ", firVisitorVoidType.render(), ") = acceptChildren(visitor, null)")
+
+                // TODO: Add a kDoc for `transformChildren`
+                printTransformChildrenMethod(element, firTransformerType, returnType = AbstractFirTreeBuilder.baseFirElement, kDoc = null)
                 println()
-                println("fun acceptChildren(visitor: ${firVisitorVoidType.render()}) = acceptChildren(visitor, null)")
-                if (element.hasTransformChildrenMethod) {
-                    println()
-                    println("fun <D> transformChildren(transformer: ${firTransformerType.render()}<D>, data: D): FirElement")
-                }
             }
         }
-        println("}")
     }
 }
+
+fun Element.generateCode(generationPath: File): GeneratedFile =
+    printGeneratedType(generationPath, TREE_GENERATOR_README, packageName, typeName) {
+        println()
+        ElementPrinter(this).printElement(element)
+    }

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

@@ -9,10 +9,8 @@ import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.tree.generator.*
 import org.jetbrains.kotlin.fir.tree.generator.model.*
 import org.jetbrains.kotlin.generators.tree.*
-import org.jetbrains.kotlin.generators.tree.printer.GeneratedFile
+import org.jetbrains.kotlin.generators.tree.printer.*
 import org.jetbrains.kotlin.generators.tree.printer.braces
-import org.jetbrains.kotlin.generators.tree.printer.printGeneratedType
-import org.jetbrains.kotlin.generators.tree.printer.typeParameters
 import org.jetbrains.kotlin.utils.SmartPrinter
 import org.jetbrains.kotlin.utils.addToStdlib.ifNotEmpty
 import org.jetbrains.kotlin.utils.withIndent
@@ -86,12 +84,6 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
         val isInterface = kind == ImplementationKind.Interface || kind == ImplementationKind.SealedInterface
         val isAbstract = kind == ImplementationKind.AbstractClass || kind == ImplementationKind.SealedClass
 
-        fun abstract() {
-            if (isAbstract) {
-                print("abstract ")
-            }
-        }
-
         val fieldPrinter = ImplementationFieldPrinter(this@printImplementation)
 
         if (!isInterface && !isAbstract && fieldsWithoutDefault.isNotEmpty()) {
@@ -128,9 +120,6 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
                 fieldsWithDefault.forEach {
                     fieldPrinter.printField(it, override = true)
                 }
-                if (fieldsWithDefault.isNotEmpty()) {
-                    println()
-                }
             }
 
 
@@ -146,6 +135,7 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
 
             val customCalls = fieldsWithoutDefault.filter { it.customInitializationCall != null }
             if (bindingCalls.isNotEmpty() || customCalls.isNotEmpty()) {
+                println()
                 println("init {")
                 withIndent {
                     for (symbolField in bindingCalls) {
@@ -158,12 +148,13 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
                     }
                 }
                 println("}")
-                println()
             }
 
             fun Field.acceptString(): String = "${name}${call()}accept(visitor, data)"
+
             if (hasAcceptChildrenMethod) {
-                print("override fun <R, D> acceptChildren(visitor: ${firVisitorType.render()}<R, D>, data: D) {")
+                printAcceptChildrenMethod(this, firVisitorType, TypeVariable("R"), override = true, kDoc = null)
+                print(" {")
 
                 val walkableFields = walkableChildren
                 if (walkableFields.isNotEmpty()) {
@@ -223,16 +214,16 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
                     }
                 }
                 println("}")
-                println()
             }
 
             if (hasTransformChildrenMethod) {
-                abstract()
-                print(
-                    "override fun <D> transformChildren(transformer: ",
-                    firTransformerType.render(),
-                    "<D>, data: D): ",
-                    render(),
+                printTransformChildrenMethod(
+                    this,
+                    firTransformerType,
+                    this,
+                    modality = Modality.ABSTRACT.takeIf { isAbstract },
+                    override = true,
+                    kDoc = null,
                 )
                 if (!isInterface && !isAbstract) {
                     println(" {")
@@ -286,17 +277,15 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
                         }
                         println("return this")
                     }
-                    println("}")
-                } else {
-                    println()
+                    print("}")
                 }
+                println()
             }
 
             for (field in allFields) {
                 if (!field.needsSeparateTransform) continue
                 println()
-                abstract()
-                print("override ${field.transformFunctionDeclaration(this)}")
+                transformFunctionDeclaration(field, this, override = true, kind!!)
                 if (isInterface || isAbstract) {
                     println()
                     continue
@@ -327,13 +316,7 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
 
             if (element.needTransformOtherChildren) {
                 println()
-                abstract()
-                print(
-                    "override fun <D> transformOtherChildren(transformer: ",
-                    firTransformerType.render(),
-                    "<D>, data: D): ",
-                    render(),
-                )
+                transformOtherChildrenFunctionDeclaration(this, override = true, kind!!)
                 if (isInterface || isAbstract) {
                     println()
                 } else {
@@ -364,8 +347,7 @@ fun SmartPrinter.printImplementation(implementation: Implementation) {
                 if (field.name == "source") {
                     println("@${firImplementationDetailType.render()}")
                 }
-                abstract()
-                print("override ${field.replaceFunctionDeclaration(overridenType, forceNullable)}")
+                replaceFunctionDeclaration(field, override = true, kind!!, overridenType, forceNullable)
                 if (isInterface || isAbstract) {
                     println()
                     return

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

@@ -37,7 +37,7 @@ private class TransformerPrinter(
     override val visitorDataType: TypeRef
         get() = dataTypeVariable
 
-    override fun visitMethodReturnType(element: Element) = element.transformerType
+    override fun visitMethodReturnType(element: Element) = element.transformerClass
 
     override val allowTypeParametersInVisitorMethods: Boolean
         get() = true

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

@@ -5,30 +5,77 @@
 
 package org.jetbrains.kotlin.fir.tree.generator.printer
 
+import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.tree.generator.firTransformerType
 import org.jetbrains.kotlin.fir.tree.generator.model.*
 import org.jetbrains.kotlin.generators.tree.*
+import org.jetbrains.kotlin.generators.tree.printer.FunctionParameter
+import org.jetbrains.kotlin.generators.tree.printer.printFunctionDeclaration
+import org.jetbrains.kotlin.utils.SmartPrinter
 
 context(ImportCollector)
-fun Field.transformFunctionDeclaration(returnType: TypeRef): String {
-    return transformFunctionDeclaration(name.replaceFirstChar(Char::uppercaseChar), returnType)
+fun SmartPrinter.transformFunctionDeclaration(
+    field: Field,
+    returnType: TypeRef,
+    override: Boolean,
+    implementationKind: ImplementationKind,
+) {
+    transformFunctionDeclaration(field.name.replaceFirstChar(Char::uppercaseChar), returnType, override, implementationKind)
 }
 
 context(ImportCollector)
-fun transformFunctionDeclaration(transformName: String, returnType: TypeRef): String {
-    return "fun <D> transform$transformName(transformer: ${firTransformerType.render()}<D>, data: D): " +
-            returnType.render()
+fun SmartPrinter.transformOtherChildrenFunctionDeclaration(
+    element: TypeRef,
+    override: Boolean,
+    implementationKind: ImplementationKind,
+) {
+    transformFunctionDeclaration("OtherChildren", element, override, implementationKind)
 }
 
 context(ImportCollector)
-fun Field.replaceFunctionDeclaration(
-    overridenType: TypeRefWithNullability? = null,
+private fun SmartPrinter.transformFunctionDeclaration(
+    transformName: String,
+    returnType: TypeRef,
+    override: Boolean,
+    implementationKind: ImplementationKind,
+) {
+    val dataTP = TypeVariable("D")
+    printFunctionDeclaration(
+        name = "transform$transformName",
+        parameters = listOf(
+            FunctionParameter("transformer", firTransformerType.withArgs(dataTP)),
+            FunctionParameter("data", dataTP),
+        ),
+        returnType = returnType,
+        typeParameters = listOf(dataTP),
+        modality = Modality.ABSTRACT.takeIf {
+            implementationKind == ImplementationKind.AbstractClass || implementationKind == ImplementationKind.SealedClass
+        },
+        override = override,
+    )
+}
+
+context(ImportCollector)
+fun SmartPrinter.replaceFunctionDeclaration(
+    field: Field,
+    override: Boolean,
+    implementationKind: ImplementationKind,
+    overriddenType: TypeRefWithNullability? = null,
     forceNullable: Boolean = false,
-): String {
-    val capName = name.replaceFirstChar(Char::uppercaseChar)
-    val type = overridenType ?: typeRef
+) {
+    val capName = field.name.replaceFirstChar(Char::uppercaseChar)
+    val type = overriddenType ?: field.typeRef
     val typeWithNullable = if (forceNullable) type.copy(nullable = true) else type
-    return "fun replace$capName(new$capName: ${typeWithNullable.render()})"
+
+    printFunctionDeclaration(
+        name = "replace$capName",
+        parameters = listOf(FunctionParameter("new$capName", typeWithNullable)),
+        returnType = StandardTypes.unit,
+        modality = Modality.ABSTRACT.takeIf {
+            implementationKind == ImplementationKind.AbstractClass || implementationKind == ImplementationKind.SealedClass
+        },
+        override = override,
+    )
 }
 
 fun Field.getMutableType(forBuilder: Boolean = false): TypeRefWithNullability = when (this) {

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

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2010-2023 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.
+ */
+
+package org.jetbrains.kotlin.generators.tree
+
+import org.jetbrains.kotlin.descriptors.Modality
+import org.jetbrains.kotlin.generators.tree.printer.*
+import org.jetbrains.kotlin.utils.SmartPrinter
+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>(
+    private val printer: SmartPrinter,
+) {
+
+    protected abstract fun makeFieldPrinter(printer: SmartPrinter): AbstractFieldPrinter<Field>
+
+    context(ImportCollector)
+    protected abstract fun SmartPrinter.printAdditionalMethods(element: Element)
+
+    protected open fun defaultElementKDoc(element: Element): String? = null
+
+    protected open val separateFieldsWithBlankLine: Boolean
+        get() = false
+
+    context(ImportCollector)
+    fun printElement(element: Element) {
+        printer.run {
+            val kind = element.kind ?: error("Expected non-null element kind")
+
+            printKDoc(element.extendedKDoc(defaultElementKDoc(element)))
+            print(kind.title, " ", element.typeName)
+            print(element.params.typeParameters())
+
+            val parentRefs = element.parentRefs
+            if (parentRefs.isNotEmpty()) {
+                print(
+                    parentRefs.sortedBy { it.typeKind }.joinToString(prefix = " : ") { parent ->
+                        parent.render() + parent.inheritanceClauseParenthesis()
+                    }
+                )
+            }
+            print(element.params.multipleUpperBoundsList())
+
+            val body = SmartPrinter(StringBuilder()).apply {
+                val fieldPrinter = makeFieldPrinter(this)
+                withIndent {
+                    for (field in element.allFields) {
+                        if (
+                            !field.withGetter && field.defaultValueInImplementation == null && field.isFinal && field.fromParent ||
+                            field.isParameter
+                        ) {
+                            continue
+                        }
+                        if (separateFieldsWithBlankLine) println()
+                        fieldPrinter.printField(
+                            field,
+                            override = field.fromParent,
+                            modality = Modality.ABSTRACT.takeIf { !field.isFinal && !kind.isInterface },
+                        )
+                    }
+                    printAdditionalMethods(element)
+                }
+            }.toString()
+
+            if (body.isNotEmpty()) {
+                println(" {")
+                print(body)
+                print("}")
+            }
+            println()
+        }
+    }
+}

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

@@ -146,4 +146,120 @@ fun SmartPrinter.printFunctionDeclaration(
         print(": ", returnType.render())
     }
     print(typeParameters.multipleUpperBoundsList())
-}
+}
+
+private val dataTP = TypeVariable("D")
+private val dataParameter = FunctionParameter("data", dataTP)
+
+context(ImportCollector)
+fun SmartPrinter.printAcceptMethod(
+    element: AbstractElement<*, *>,
+    visitorClass: ClassRef<PositionTypeParameterRef>,
+    hasImplementation: Boolean,
+    kDoc: String?,
+) {
+    if (!element.hasAcceptMethod) return
+    println()
+    printKDoc(kDoc)
+    val resultTP = TypeVariable("R")
+    printFunctionDeclaration(
+        name = "accept",
+        parameters = listOf(
+            FunctionParameter("visitor", visitorClass.withArgs(resultTP, dataTP)),
+            dataParameter,
+        ),
+        returnType = resultTP,
+        typeParameters = listOf(resultTP, dataTP),
+        override = !element.isRootElement,
+    )
+    if (hasImplementation) {
+        println(" =")
+        withIndent {
+            print("visitor.", element.visitFunctionName, "(this, ", dataParameter.name, ")")
+        }
+    }
+    println()
+}
+
+context(ImportCollector)
+fun SmartPrinter.printTransformMethod(
+    element: AbstractElement<*, *>,
+    transformerClass: ClassRef<PositionTypeParameterRef>,
+    implementation: String?,
+    returnType: TypeRefWithNullability,
+    kDoc: String?,
+) {
+    if (!element.hasTransformMethod) return
+    println()
+    printKDoc(kDoc)
+    if (returnType is TypeParameterRef && implementation != null) {
+        println("@Suppress(\"UNCHECKED_CAST\")")
+    }
+    printFunctionDeclaration(
+        name = "transform",
+        parameters = listOf(
+            FunctionParameter("transformer", transformerClass.withArgs(dataTP)),
+            dataParameter,
+        ),
+        returnType = returnType,
+        typeParameters = listOfNotNull(returnType as? TypeVariable, dataTP),
+        override = !element.isRootElement,
+    )
+    if (implementation != null) {
+        println(" =")
+        withIndent {
+            print(implementation, " as ", returnType.render())
+        }
+    }
+    println()
+}
+
+context(ImportCollector)
+fun SmartPrinter.printAcceptChildrenMethod(
+    element: FieldContainer,
+    visitorClass: ClassRef<PositionTypeParameterRef>,
+    visitorResultType: TypeRef,
+    modality: Modality? = null,
+    override: Boolean = false,
+    kDoc: String?,
+) {
+    if (!element.hasAcceptChildrenMethod) return
+    println()
+    printKDoc(kDoc)
+    printFunctionDeclaration(
+        name = "acceptChildren",
+        parameters = listOf(
+            FunctionParameter("visitor", visitorClass.withArgs(visitorResultType, dataTP)),
+            dataParameter,
+        ),
+        returnType = StandardTypes.unit,
+        typeParameters = listOfNotNull(visitorResultType as? TypeVariable, dataTP),
+        modality = modality,
+        override = override,
+    )
+}
+
+context(ImportCollector)
+fun SmartPrinter.printTransformChildrenMethod(
+    element: FieldContainer,
+    transformerClass: ClassRef<PositionTypeParameterRef>,
+    returnType: TypeRef,
+    modality: Modality? = null,
+    override: Boolean = false,
+    kDoc: String?,
+) {
+    if (!element.hasTransformChildrenMethod) return
+    println()
+    printKDoc(kDoc)
+    printFunctionDeclaration(
+        name = "transformChildren",
+        parameters = listOf(
+            FunctionParameter("transformer", transformerClass.withArgs(dataTP)),
+            dataParameter,
+        ),
+        returnType = returnType,
+        typeParameters = listOf(dataTP),
+        modality = modality,
+        override = override,
+    )
+}