[cfe] Create fields through SourcePropertyBuilder

Change-Id: I20c9dd7baa705aba77d90b94ba0a46ed64eb02ec
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/403600
Commit-Queue: Johnni Winther <[email protected]>
Reviewed-by: Chloe Stefantsova <[email protected]>

pkg/front_end/lib/src/base/incremental_compiler.dart

@@ -73,7 +73,6 @@ import '../base/processed_options.dart' show ProcessedOptions;
 import '../builder/builder.dart' show Builder;
 import '../builder/declaration_builders.dart'
     show ClassBuilder, ExtensionBuilder, ExtensionTypeDeclarationBuilder;
-import '../builder/field_builder.dart' show FieldBuilder;
 import '../builder/library_builder.dart'
     show CompilationUnit, LibraryBuilder, SourceCompilationUnit;
 import '../builder/member_builder.dart' show MemberBuilder;
@@ -741,7 +740,9 @@ class IncrementalCompiler implements IncrementalKernelGenerator {
       if (sourceBuilder == null) {
         sourceBuilder = sourceLibraryBuilder.exportNameSpace
             .lookupLocalMember(name, setter: false);
-        if (sourceBuilder is FieldBuilder && sourceBuilder.isAssignable) {
+        if (sourceBuilder is MemberBuilder &&
+            sourceBuilder.isField &&
+            sourceBuilder.isAssignable) {
           // Assignable fields can be lowered into a getter and setter.
           return;
         }

pkg/front_end/lib/src/base/scope.dart

@@ -687,6 +687,14 @@ mixin ErroneousMemberBuilderMixin implements SourceMemberBuilder {
   // Coverage-ignore(suite): Not run.
   bool get isAbstract => false;
 
+  @override
+  // Coverage-ignore(suite): Not run.
+  bool get isFinal => false;
+
+  @override
+  // Coverage-ignore(suite): Not run.
+  bool get isSynthesized => false;
+
   @override
   bool get isConflictingSetter => false;
 
@@ -1503,8 +1511,9 @@ extension on Builder {
       return _hasPatchAnnotation(self.metadata);
     } else if (self is SourceMethodBuilder) {
       return _hasPatchAnnotation(self.metadata);
-    } else if (self is SourceExtensionTypeDeclarationBuilder) {
-      // Coverage-ignore-block(suite): Not run.
+    }
+    // Coverage-ignore(suite): Not run.
+    else if (self is SourceExtensionTypeDeclarationBuilder) {
       return _hasPatchAnnotation(self.metadata);
     }
     return false;

pkg/front_end/lib/src/builder/builder_mixins.dart

@@ -10,7 +10,6 @@ import '../base/problems.dart';
 import '../base/scope.dart';
 import 'builder.dart';
 import 'declaration_builders.dart';
-import 'field_builder.dart';
 import 'library_builder.dart';
 import 'member_builder.dart';
 import 'nullability_builder.dart';
@@ -96,16 +95,16 @@ mixin DeclarationBuilderMixin implements IDeclarationBuilder {
     if (builder == null && setter) {
       // When looking up setters, we include assignable fields.
       builder = lookupLocalMember(name.text, setter: false, required: required);
-      if (builder is! FieldBuilder || !builder.isAssignable) {
+      if (builder is! MemberBuilder ||
+          !builder.isField ||
+          !builder.isAssignable) {
         builder = null;
       }
     }
     if (builder != null) {
       if (name.isPrivate && libraryBuilder.library != name.library) {
         builder = null;
-      } else if (builder is FieldBuilder &&
-          !builder.isStatic &&
-          !builder.isExternal) {
+      } else if (builder.isField && !builder.isStatic && !builder.isExternal) {
         // Non-external extension instance fields are invalid.
         builder = null;
       } else if (builder.isDuplicate) {

pkg/front_end/lib/src/builder/formal_parameter_builder.dart

@@ -19,13 +19,13 @@ import '../kernel/wildcard_lowering.dart';
 import '../source/builder_factory.dart';
 import '../source/constructor_declaration.dart';
 import '../source/source_factory_builder.dart';
-import '../source/source_field_builder.dart';
 import '../source/source_library_builder.dart';
 import 'builder.dart';
 import 'constructor_builder.dart';
 import 'declaration_builders.dart';
 import 'member_builder.dart';
 import 'omitted_type_builder.dart';
+import 'property_builder.dart';
 import 'type_builder.dart';
 import 'variable_builder.dart';
 
@@ -229,7 +229,7 @@ class FormalParameterBuilder extends BuilderImpl
       ClassHierarchyBase hierarchy) {
     String fieldName = isWildcardLoweredFormalParameter(name) ? '_' : name;
     Builder? fieldBuilder = declarationBuilder.lookupLocalMember(fieldName);
-    if (fieldBuilder is SourceFieldBuilder) {
+    if (fieldBuilder is PropertyBuilder && fieldBuilder.isField) {
       DartType fieldType = fieldBuilder.inferType(hierarchy);
       fieldType = constructorDeclaration.substituteFieldType(fieldType);
       type.registerInferredType(fieldType);

pkg/front_end/lib/src/builder/invalid_type_declaration_builder.dart

@@ -28,7 +28,7 @@ class InvalidTypeDeclarationBuilder extends TypeDeclarationBuilderImpl
 
   @override
   // Coverage-ignore(suite): Not run.
-  Uri? get fileUri => message.uri;
+  Uri get fileUri => message.uri!;
 
   @override
   DartType buildAliasedType(

pkg/front_end/lib/src/builder/member_builder.dart

@@ -186,6 +186,7 @@ abstract class BuilderClassMember implements ClassMember {
   Uri get fileUri => memberBuilder.fileUri;
 
   @override
+  // Coverage-ignore(suite): Not run.
   bool get isExtensionTypeMember => memberBuilder.isExtensionTypeMember;
 
   @override
@@ -206,6 +207,7 @@ abstract class BuilderClassMember implements ClassMember {
   bool get isDuplicate => memberBuilder.isDuplicate;
 
   @override
+  // Coverage-ignore(suite): Not run.
   bool get isField => memberBuilder.isField;
 
   @override
@@ -231,9 +233,11 @@ abstract class BuilderClassMember implements ClassMember {
   bool get isSynthesized => false;
 
   @override
+  // Coverage-ignore(suite): Not run.
   bool get isInternalImplementation => false;
 
   @override
+  // Coverage-ignore(suite): Not run.
   bool get isNoSuchMethodForwarder => false;
 
   @override

pkg/front_end/lib/src/builder/property_builder.dart

@@ -0,0 +1,41 @@
+// Copyright (c) 2025, 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.
+
+import 'package:kernel/ast.dart';
+import 'package:kernel/class_hierarchy.dart';
+
+import 'member_builder.dart';
+
+abstract class PropertyBuilder implements MemberBuilder {
+  bool get hasInitializer;
+
+  @override
+  Uri get fileUri;
+
+  bool get isExtensionTypeDeclaredInstanceField;
+
+  bool get isLate;
+
+  bool get isFinal;
+
+  abstract DartType fieldType;
+
+  DartType inferType(ClassHierarchyBase hierarchy);
+
+  /// Builds the field initializers for each field used to encode this field
+  /// using the [fileOffset] for the created nodes and [value] as the initial
+  /// field value.
+  List<Initializer> buildInitializer(int fileOffset, Expression value,
+      {required bool isSynthetic});
+
+  /// Creates the AST node for this field as the default initializer.
+  void buildImplicitDefaultValue();
+
+  /// Create the [Initializer] for the implicit initialization of this field
+  /// in a constructor.
+  Initializer buildImplicitInitializer();
+
+  Initializer buildErroneousInitializer(Expression effect, Expression value,
+      {required int fileOffset});
+}