[cfe] Don't create ClassMember for internal implementation

Internal implementation members, like those used for the late lowering, are not real instance members on should not be part of the hierarchy member computation. These members are only called directly from within the members for which these are generated, so we don't need to add forwarders and stubs to handle calls from the outside.

Closes #49339

Change-Id: I4d87477243d4e015265c7bb200e1fb5431ae21f9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/424943
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

Author: johnniwinther

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

@@ -212,10 +212,6 @@ abstract class BuilderClassMember implements ClassMember {
   // Coverage-ignore(suite): Not run.
   bool get isSynthesized => false;
 
-  @override
-  // Coverage-ignore(suite): Not run.
-  bool get isInternalImplementation => false;
-
   @override
   // Coverage-ignore(suite): Not run.
   bool get isNoSuchMethodForwarder => false;

pkg/front_end/lib/src/dill/dill_builder_mixins.dart

@@ -98,12 +98,15 @@ mixin DillFieldBuilderMixin implements DillMemberBuilder, PropertyBuilder {
 
   @override
   List<ClassMember> get localMembers =>
-      _localMembers ??= [new DillClassMember(this, ClassMemberKind.Getter)];
+      _localMembers ??= !member.isInternalImplementation
+          ? [new DillClassMember(this, ClassMemberKind.Getter)]
+          : const [];
 
   @override
-  List<ClassMember> get localSetters => _localSetters ??= hasSetter
-      ? [new DillClassMember(this, ClassMemberKind.Setter)]
-      : const [];
+  List<ClassMember> get localSetters =>
+      _localSetters ??= hasSetter && !member.isInternalImplementation
+          ? [new DillClassMember(this, ClassMemberKind.Setter)]
+          : const [];
 }
 
 mixin DillGetterBuilderMixin implements DillMemberBuilder, PropertyBuilder {
@@ -136,7 +139,9 @@ mixin DillGetterBuilderMixin implements DillMemberBuilder, PropertyBuilder {
 
   @override
   List<ClassMember> get localMembers =>
-      _localMembers ??= [new DillClassMember(this, ClassMemberKind.Getter)];
+      _localMembers ??= !member.isInternalImplementation
+          ? [new DillClassMember(this, ClassMemberKind.Getter)]
+          : const [];
 
   @override
   List<ClassMember> get localSetters => const [];
@@ -179,7 +184,9 @@ mixin DillSetterBuilderMixin implements DillMemberBuilder, PropertyBuilder {
 
   @override
   List<ClassMember> get localSetters =>
-      _localSetters ??= [new DillClassMember(this, ClassMemberKind.Setter)];
+      _localSetters ??= !member.isInternalImplementation
+          ? [new DillClassMember(this, ClassMemberKind.Setter)]
+          : const [];
 }
 
 mixin DillMethodBuilderMixin implements DillMemberBuilder, MethodBuilder {
@@ -207,7 +214,9 @@ mixin DillMethodBuilderMixin implements DillMemberBuilder, MethodBuilder {
 
   @override
   List<ClassMember> get localMembers =>
-      _localMembers ??= [new DillClassMember(this, ClassMemberKind.Method)];
+      _localMembers ??= !member.isInternalImplementation
+          ? [new DillClassMember(this, ClassMemberKind.Method)]
+          : const [];
 
   @override
   List<ClassMember> get localSetters => const [];
@@ -247,7 +256,9 @@ mixin DillOperatorBuilderMixin implements DillMemberBuilder, MethodBuilder {
 
   @override
   List<ClassMember> get localMembers =>
-      _localMembers ??= [new DillClassMember(this, ClassMemberKind.Method)];
+      _localMembers ??= !member.isInternalImplementation
+          ? [new DillClassMember(this, ClassMemberKind.Method)]
+          : const [];
 
   @override
   List<ClassMember> get localSetters => const [];

pkg/front_end/lib/src/dill/dill_member_builder.dart

@@ -322,7 +322,11 @@ class DillClassMember extends BuilderClassMember {
   @override
   final ClassMemberKind memberKind;
 
-  DillClassMember(this.memberBuilder, this.memberKind);
+  DillClassMember(this.memberBuilder, this.memberKind)
+      : assert(
+            !memberBuilder.member.isInternalImplementation,
+            "ClassMember should not be created for internal implementation "
+            "member $memberBuilder.");
 
   @override
   bool get isSourceDeclaration => false;
@@ -333,12 +337,6 @@ class DillClassMember extends BuilderClassMember {
     return member.isExtensionTypeMember;
   }
 
-  @override
-  bool get isInternalImplementation {
-    Member member = memberBuilder.member;
-    return member.isInternalImplementation;
-  }
-
   @override
   bool get isNoSuchMethodForwarder {
     Member member = memberBuilder.member;

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

@@ -163,10 +163,6 @@ class _EnumElementClassMember implements ClassMember {
   // Coverage-ignore(suite): Not run.
   bool get isExtensionTypeMember => _builder.isExtensionTypeMember;
 
-  @override
-  // Coverage-ignore(suite): Not run.
-  bool get isInternalImplementation => false;
-
   @override
   // Coverage-ignore(suite): Not run.
   bool get isNoSuchMethodForwarder => false;

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

@@ -103,9 +103,6 @@ class _FieldClassMember implements ClassMember {
   @override
   bool get isExtensionTypeMember => _builder.isExtensionTypeMember;
 
-  @override
-  bool get isInternalImplementation => false;
-
   @override
   bool get isNoSuchMethodForwarder => false;
 
@@ -174,9 +171,6 @@ class _SynthesizedFieldClassMember implements ClassMember {
   _SynthesizedFieldClassMember(
       this._builder, this._member, this._name, this._kind, this.memberKind);
 
-  @override
-  bool get isInternalImplementation => _kind.isInternalImplementation;
-
   @override
   Member getMember(ClassMembersBuilder membersBuilder) {
     inferType(membersBuilder);
@@ -307,23 +301,12 @@ class _SynthesizedFieldClassMember implements ClassMember {
 }
 
 enum _SynthesizedFieldMemberKind {
-  /// A `isSet` field used for late lowering.
-  LateIsSet(isInternalImplementation: true),
-
-  /// A field used for the value of a late lowered field.
-  LateField(isInternalImplementation: true),
-
   /// A getter or setter used for late lowering.
-  LateGetterSetter(isInternalImplementation: false),
+  LateGetterSetter,
 
   /// A getter or setter used for abstract or external fields.
-  AbstractExternalGetterSetter(isInternalImplementation: false),
+  AbstractExternalGetterSetter,
 
   /// A getter for an extension type declaration representation field.
-  RepresentationField(isInternalImplementation: false),
-  ;
-
-  final bool isInternalImplementation;
-
-  const _SynthesizedFieldMemberKind({required this.isInternalImplementation});
+  RepresentationField,
 }

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

@@ -475,6 +475,7 @@ abstract class AbstractLateFieldEncoding implements FieldEncoding {
   }
 
   @override
+  // Coverage-ignore(suite): Not run.
   Field get field => _field!;
 
   @override
@@ -635,52 +636,26 @@ abstract class AbstractLateFieldEncoding implements FieldEncoding {
   }
 
   @override
-  List<ClassMember> get localMembers {
-    List<ClassMember> list = [
-      new _SynthesizedFieldClassMember(_fragment.builder, field, field.name,
-          _SynthesizedFieldMemberKind.LateField, ClassMemberKind.Getter),
-      new _SynthesizedFieldClassMember(
-          _fragment.builder,
-          _lateGetter!,
-          _fragment.builder.memberName,
-          _SynthesizedFieldMemberKind.LateGetterSetter,
-          ClassMemberKind.Getter)
-    ];
-    if (_lateIsSetField != null) {
-      list.add(new _SynthesizedFieldClassMember(
-          _fragment.builder,
-          _lateIsSetField!,
-          _lateIsSetField!.name,
-          _SynthesizedFieldMemberKind.LateIsSet,
-          ClassMemberKind.Getter));
-    }
-    return list;
-  }
+  List<ClassMember> get localMembers => [
+        new _SynthesizedFieldClassMember(
+            _fragment.builder,
+            _lateGetter!,
+            _fragment.builder.memberName,
+            _SynthesizedFieldMemberKind.LateGetterSetter,
+            ClassMemberKind.Getter)
+      ];
 
   @override
-  List<ClassMember> get localSetters {
-    List<ClassMember> list = [
-      new _SynthesizedFieldClassMember(_fragment.builder, field, field.name,
-          _SynthesizedFieldMemberKind.LateField, ClassMemberKind.Setter),
-    ];
-    if (_lateIsSetField != null) {
-      list.add(new _SynthesizedFieldClassMember(
-          _fragment.builder,
-          _lateIsSetField!,
-          _lateIsSetField!.name,
-          _SynthesizedFieldMemberKind.LateIsSet,
-          ClassMemberKind.Setter));
-    }
-    if (_lateSetter != null) {
-      list.add(new _SynthesizedFieldClassMember(
-          _fragment.builder,
-          _lateSetter!,
-          _fragment.builder.memberName,
-          _SynthesizedFieldMemberKind.LateGetterSetter,
-          ClassMemberKind.Setter));
-    }
-    return list;
-  }
+  List<ClassMember> get localSetters => _lateSetter != null
+      ? [
+          new _SynthesizedFieldClassMember(
+              _fragment.builder,
+              _lateSetter!,
+              _fragment.builder.memberName,
+              _SynthesizedFieldMemberKind.LateGetterSetter,
+              ClassMemberKind.Setter)
+        ]
+      : const [];
 
   @override
   void registerSuperCall() {

pkg/front_end/lib/src/kernel/hierarchy/class_member.dart

@@ -266,13 +266,6 @@ abstract class ClassMember {
   /// source code.
   bool get isSynthesized;
 
-  /// If `true` this member is not part of the interface but only part of the
-  /// class members.
-  ///
-  /// This is `true` for instance for synthesized fields added for the late
-  /// lowering.
-  bool get isInternalImplementation;
-
   /// Returns `true` if this member is a noSuchMethod forwarder.
   bool get isNoSuchMethodForwarder;
 
@@ -375,9 +368,6 @@ abstract class SynthesizedMember extends ClassMember {
   @override
   bool get isDuplicate => false;
 
-  @override
-  bool get isInternalImplementation => false;
-
   @override
   bool get isSetter => forSetter;
 

pkg/front_end/lib/src/kernel/hierarchy/members_node.dart

@@ -559,36 +559,7 @@ class ClassMembersNodeBuilder extends MembersNodeBuilder {
   ///
   void registerAbstractMember(
       List<ClassMember> abstractMembers, ClassMember abstractMember) {
-    if (!abstractMember.isInternalImplementation) {
-      /// If `isInternalImplementation` is `true`, the member is synthesized
-      /// implementation that does not require implementation in other
-      /// classes.
-      ///
-      /// This is for instance used for late lowering where
-      ///
-      ///    class Interface {
-      ///      late int? field;
-      ///    }
-      ///    class Class implements Interface {
-      ///      int? field;
-      ///    }
-      ///
-      /// is encoded as
-      ///
-      ///    class Interface {
-      ///      bool _#field#isSet = false;
-      ///      int? _#field = null;
-      ///      int? get field => _#field#isSet ? _#field : throw ...;
-      ///      void set field(int? value) { ... }
-      ///    }
-      ///    class Class implements Interface {
-      ///      int? field;
-      ///    }
-      ///
-      /// and `Class` should not be required to implement
-      /// `Interface._#field#isSet` and `Interface._#field`.
-      abstractMembers.add(abstractMember);
-    }
+    abstractMembers.add(abstractMember);
   }
 
   /// Set to `true` during [build] if the class needs interfaces, that is, if it

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

@@ -873,10 +873,6 @@ class _EnumValuesClassMember implements ClassMember {
   // Coverage-ignore(suite): Not run.
   bool get isExtensionTypeMember => _builder.isExtensionTypeMember;
 
-  @override
-  // Coverage-ignore(suite): Not run.
-  bool get isInternalImplementation => false;
-
   @override
   // Coverage-ignore(suite): Not run.
   bool get isNoSuchMethodForwarder => false;

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

@@ -364,9 +364,6 @@ class _MethodClassMember implements ClassMember {
   @override
   bool get isExtensionTypeMember => _builder.isExtensionTypeMember;
 
-  @override
-  bool get isInternalImplementation => false;
-
   @override
   bool get isNoSuchMethodForwarder => false;
 

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

@@ -692,9 +692,6 @@ class _GetterClassMember implements ClassMember {
   @override
   bool get isExtensionTypeMember => _builder.isExtensionTypeMember;
 
-  @override
-  bool get isInternalImplementation => false;
-
   @override
   bool get isNoSuchMethodForwarder => false;
 
@@ -829,9 +826,6 @@ class _SetterClassMember implements ClassMember {
   @override
   bool get isExtensionTypeMember => _builder.isExtensionTypeMember;
 
-  @override
-  bool get isInternalImplementation => false;
-
   @override
   bool get isNoSuchMethodForwarder => false;