[cfe] Add ConstructorName

This combines the information about a constructor name needed to refer
to its simple and full name and the corresponding offsets into a single
class which is then used on fragments.

Change-Id: Ibed0456c4517d15fde59f591a05286c5dd2b3204
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/392423
Commit-Queue: Johnni Winther <[email protected]>
Reviewed-by: Chloe Stefantsova <[email protected]>

Author: johnniwinther

pkg/front_end/lib/src/fragment/constructor.dart

@@ -5,12 +5,10 @@
 part of 'fragment.dart';
 
 class ConstructorFragment implements Fragment, FunctionFragment {
-  @override
-  final String name;
+  final ConstructorName constructorName;
 
   final Uri fileUri;
   final int startOffset;
-  final int nameOffset;
   final int formalsOffset;
   final int endOffset;
   final Modifiers modifiers;
@@ -26,10 +24,9 @@ class ConstructorFragment implements Fragment, FunctionFragment {
   AbstractSourceConstructorBuilder? _builder;
 
   ConstructorFragment(
-      {required this.name,
+      {required this.constructorName,
       required this.fileUri,
       required this.startOffset,
-      required this.nameOffset,
       required this.formalsOffset,
       required this.endOffset,
       required this.modifiers,
@@ -43,6 +40,11 @@ class ConstructorFragment implements Fragment, FunctionFragment {
       required Token? beginInitializers})
       : _beginInitializers = beginInitializers;
 
+  @override
+  String get name => constructorName.name;
+
+  int get fullNameOffset => constructorName.fullNameOffset;
+
   Token? get beginInitializers {
     Token? result = _beginInitializers;
     // Ensure that we don't hold onto the token.
@@ -67,7 +69,7 @@ class ConstructorFragment implements Fragment, FunctionFragment {
   }
 
   @override
-  String toString() => '$runtimeType($name,$fileUri,$nameOffset)';
+  String toString() => '$runtimeType($name,$fileUri,$fullNameOffset)';
 }
 
 class _ConstructorBodyBuildingContext implements FunctionBodyBuildingContext {

pkg/front_end/lib/src/fragment/factory.dart

@@ -5,12 +5,10 @@
 part of 'fragment.dart';
 
 class FactoryFragment implements Fragment, FunctionFragment {
-  @override
-  final String name;
+  final ConstructorName constructorName;
 
   final Uri fileUri;
   final int startOffset;
-  final int nameOffset;
   final int formalsOffset;
   final int endOffset;
   final Modifiers modifiers;
@@ -26,10 +24,9 @@ class FactoryFragment implements Fragment, FunctionFragment {
   SourceFactoryBuilder? _builder;
 
   FactoryFragment(
-      {required this.name,
+      {required this.constructorName,
       required this.fileUri,
       required this.startOffset,
-      required this.nameOffset,
       required this.formalsOffset,
       required this.endOffset,
       required this.modifiers,
@@ -42,6 +39,11 @@ class FactoryFragment implements Fragment, FunctionFragment {
       required this.nativeMethodName,
       required this.redirectionTarget});
 
+  @override
+  String get name => constructorName.name;
+
+  int get fullNameOffset => constructorName.fullNameOffset;
+
   @override
   SourceFactoryBuilder get builder {
     assert(_builder != null, "Builder has not been computed for $this.");
@@ -59,7 +61,7 @@ class FactoryFragment implements Fragment, FunctionFragment {
   }
 
   @override
-  String toString() => '$runtimeType($name,$fileUri,$nameOffset)';
+  String toString() => '$runtimeType($name,$fileUri,$fullNameOffset)';
 }
 
 class _FactoryBodyBuildingContext implements FunctionBodyBuildingContext {

pkg/front_end/lib/src/fragment/fragment.dart

@@ -45,6 +45,7 @@ part 'named_mixin_application.dart';
 part 'primary_constructor.dart';
 part 'setter.dart';
 part 'typedef.dart';
+part 'util.dart';
 
 sealed class Fragment {
   /// The declared name of this fragment.

pkg/front_end/lib/src/fragment/primary_constructor.dart

@@ -5,12 +5,10 @@
 part of 'fragment.dart';
 
 class PrimaryConstructorFragment implements Fragment, FunctionFragment {
-  @override
-  final String name;
+  final ConstructorName constructorName;
 
   final Uri fileUri;
   final int startOffset;
-  final int? nameOffset;
   final int formalsOffset;
   final Modifiers modifiers;
   final OmittedTypeBuilder returnType;
@@ -23,10 +21,9 @@ class PrimaryConstructorFragment implements Fragment, FunctionFragment {
   AbstractSourceConstructorBuilder? _builder;
 
   PrimaryConstructorFragment(
-      {required this.name,
+      {required this.constructorName,
       required this.fileUri,
       required this.startOffset,
-      required this.nameOffset,
       required this.formalsOffset,
       required this.modifiers,
       required this.returnType,
@@ -37,7 +34,10 @@ class PrimaryConstructorFragment implements Fragment, FunctionFragment {
       required Token? beginInitializers})
       : _beginInitializers = beginInitializers;
 
-  int get fileOffset => nameOffset ?? formalsOffset;
+  @override
+  String get name => constructorName.name;
+
+  int get fileOffset => constructorName.nameOffset ?? formalsOffset;
 
   Token? get beginInitializers {
     Token? result = _beginInitializers;

pkg/front_end/lib/src/fragment/util.dart

@@ -0,0 +1,36 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+part of 'fragment.dart';
+
+class ConstructorName {
+  /// The name of the constructor itself.
+  ///
+  /// For an unnamed constructor, this is ''.
+  final String name;
+
+  /// The offset of the name of the constructor, if the constructor is not
+  /// unnamed.
+  final int? nameOffset;
+
+  /// The name of the constructor including the enclosing declaration name.
+  final String fullName;
+
+  /// The offset at which [fullName] occurs.
+  ///
+  /// This is used in messages to put the `^` at the start of the [fullName].
+  final int fullNameOffset;
+
+  /// The number of characters of [fullName] that occurs at [fullNameOffset].
+  ///
+  /// This is used in messages to put the right amount of `^` under the name.
+  final int fullNameLength;
+
+  ConstructorName(
+      {required this.name,
+      required this.nameOffset,
+      required this.fullName,
+      required this.fullNameOffset,
+      required this.fullNameLength});
+}

pkg/front_end/lib/src/source/builder_factory.dart

@@ -21,6 +21,7 @@ import '../builder/named_type_builder.dart';
 import '../builder/nullability_builder.dart';
 import '../builder/omitted_type_builder.dart';
 import '../builder/type_builder.dart';
+import '../fragment/fragment.dart';
 import 'offset_map.dart';
 import 'source_class_builder.dart';
 import 'source_enum_builder.dart';
@@ -319,11 +320,10 @@ abstract class BuilderFactory {
       required List<MetadataBuilder>? metadata,
       required Modifiers modifiers,
       required Identifier identifier,
-      required String constructorName,
+      required ConstructorName constructorName,
       required List<NominalParameterBuilder>? typeParameters,
       required List<FormalParameterBuilder>? formals,
       required int startOffset,
-      required int nameOffset,
       required int formalsOffset,
       required int endOffset,
       required String? nativeMethodName,
@@ -333,7 +333,7 @@ abstract class BuilderFactory {
   void addPrimaryConstructor(
       {required OffsetMap offsetMap,
       required Token beginToken,
-      required String constructorName,
+      required String? name,
       required List<FormalParameterBuilder>? formals,
       required int startOffset,
       required int? nameOffset,
@@ -360,7 +360,7 @@ abstract class BuilderFactory {
       required String? nativeMethodName,
       required AsyncMarker asyncModifier});
 
-  String? computeAndValidateConstructorName(
+  ConstructorName computeAndValidateConstructorName(
       DeclarationFragment enclosingDeclaration, Identifier identifier,
       {isFactory = false});
 
@@ -500,6 +500,6 @@ class FieldInfo {
   final Token? beforeLast;
   final int endOffset;
 
-  const FieldInfo(this.identifier, this.initializerToken, this.beforeLast,
-      this.endOffset);
+  const FieldInfo(
+      this.identifier, this.initializerToken, this.beforeLast, this.endOffset);
 }

pkg/front_end/lib/src/source/outline_builder.dart

@@ -1588,12 +1588,12 @@ class OutlineBuilder extends StackListenerImpl {
     int? nameOffset;
     int formalsOffset = charOffset;
 
-    String constructorName = '';
+    String? name;
     if (hasConstructorName) {
       // TODO(johnniwinther): Handle [ParserRecovery].
       Identifier identifier = pop() as Identifier;
       nameOffset = charOffset = identifier.nameOffset;
-      constructorName = identifier.name;
+      name = identifier.name;
     }
 
     int? startOffset = constKeyword?.charOffset ?? nameOffset ?? formalsOffset;
@@ -1684,7 +1684,7 @@ class OutlineBuilder extends StackListenerImpl {
     _builderFactory.addPrimaryConstructor(
         offsetMap: _offsetMap,
         beginToken: beginToken,
-        constructorName: constructorName == "new" ? "" : constructorName,
+        name: name,
         startOffset: startOffset,
         nameOffset: nameOffset,
         formalsOffset: formalsOffset,