Fine. Unify manifest item hierarchy and rename member items.

Refactor the fine-grained manifest model to reduce duplication and make
member representations consistent across top-level and instance scopes.

Key changes
- Replace many ad-hoc item types with shared bases:
  - Introduce `ExecutableItem` and `VariableItem`.
  - Add concrete items: `ConstructorItem`, `MethodItem`, `GetterItem`,
    `SetterItem`, `FieldItem`.
  - Make `TopLevelFunctionItem` extend `ExecutableItem` and
    `TopLevelVariableItem` extend `VariableItem`.
  - Remove `TopLevelItem` and the previous
    `InstanceItem{Field,Getter,Setter,Method}Item`,
    `InterfaceItemConstructorItem`,
    `TopLevel{Getter,Setter}Item`.
- Normalize maps and APIs:
  - `LibraryManifest.declaredGetters/declaredSetters` now map to
    `GetterItem`/`SetterItem`.
  - `exportedIds` aggregates over `Map<LookupName, ManifestItem>` instead
    of `TopLevelItem`.
  - Matching logic simplifies to presence checks; type guards on the old
    item classes are no longer needed.
- Unify function typing:
  - Getters and setters now carry a full `functionType` (setters previously
    stored only a `valueType`; getters now print return types via
    `functionType.returnType`).
- Update printers and ID lookup to the new structure.
- Bump persisted data format: `DATA_VERSION 544 → 545`.

Why
- Consolidates parallel class hierarchies into a single, coherent model.
- Eliminates redundant code paths and special-case handling between
  top-level and instance members.
- Makes future additions (e.g., executable flags) consistent by moving
  shared properties into `ExecutableItem`.
- Keeps item IDs stable when semantics don’t change while simplifying the
  matching and serialization logic.

Change-Id: Ie9c097eae71a2abea874468a740050ae4fe3a570
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/448760
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/analysis/driver.dart

@@ -106,7 +106,7 @@ testFineAfterLibraryAnalyzerHook;
 // TODO(scheglov): Clean up the list of implicitly analyzed files.
 class AnalysisDriver {
   /// The version of data format, should be incremented on every format change.
-  static const int DATA_VERSION = 544;
+  static const int DATA_VERSION = 545;
 
   /// The number of exception contexts allowed to write. Once this field is
   /// zero, we stop writing any new exception contexts in this process.

pkg/analyzer/lib/src/fine/library_manifest.dart

@@ -30,8 +30,8 @@ class LibraryManifest {
   final Map<LookupName, ExtensionTypeItem> declaredExtensionTypes;
   final Map<LookupName, MixinItem> declaredMixins;
   final Map<LookupName, TypeAliasItem> declaredTypeAliases;
-  final Map<LookupName, TopLevelGetterItem> declaredGetters;
-  final Map<LookupName, TopLevelSetterItem> declaredSetters;
+  final Map<LookupName, GetterItem> declaredGetters;
+  final Map<LookupName, SetterItem> declaredSetters;
   final Map<LookupName, TopLevelFunctionItem> declaredFunctions;
   final Map<LookupName, TopLevelVariableItem> declaredVariables;
 
@@ -75,10 +75,10 @@ class LibraryManifest {
         readValue: () => TypeAliasItem.read(reader),
       ),
       declaredGetters: reader.readLookupNameMap(
-        readValue: () => TopLevelGetterItem.read(reader),
+        readValue: () => GetterItem.read(reader),
       ),
       declaredSetters: reader.readLookupNameMap(
-        readValue: () => TopLevelSetterItem.read(reader),
+        readValue: () => SetterItem.read(reader),
       ),
       declaredFunctions: reader.readLookupNameMap(
         readValue: () => TopLevelFunctionItem.read(reader),
@@ -93,7 +93,7 @@ class LibraryManifest {
   Map<LookupName, ManifestItemId> get exportedIds {
     return Map.fromEntries([
       ...reExportMap.entries,
-      ...<Map<LookupName, TopLevelItem>>[
+      ...<Map<LookupName, ManifestItem>>[
             declaredClasses,
             declaredEnums,
             declaredExtensions,
@@ -291,7 +291,7 @@ class LibraryManifestBuilder {
 
   void _addEnum({
     required EncodeContext encodingContext,
-    required Map<LookupName, TopLevelItem> newItems,
+    required Map<LookupName, EnumItem> newItems,
     required EnumElementImpl element,
     required LookupName lookupName,
   }) {
@@ -371,7 +371,7 @@ class LibraryManifestBuilder {
 
   void _addExtensionType({
     required EncodeContext encodingContext,
-    required Map<LookupName, TopLevelItem> newItems,
+    required Map<LookupName, ExtensionTypeItem> newItems,
     required ExtensionTypeElementImpl element,
     required LookupName lookupName,
   }) {
@@ -408,7 +408,7 @@ class LibraryManifestBuilder {
     }
 
     var item = _getOrBuildElementItem(element, () {
-      return InstanceItemFieldItem.fromElement(
+      return FieldItem.fromElement(
         id: ManifestItemId.generate(),
         context: encodingContext,
         element: element,
@@ -429,7 +429,7 @@ class LibraryManifestBuilder {
     }
 
     var item = _getOrBuildElementItem(element, () {
-      return InstanceItemGetterItem.fromElement(
+      return GetterItem.fromElement(
         id: ManifestItemId.generate(),
         context: encodingContext,
         element: element,
@@ -488,7 +488,7 @@ class LibraryManifestBuilder {
     }
 
     var item = _getOrBuildElementItem(element, () {
-      return InstanceItemMethodItem.fromElement(
+      return MethodItem.fromElement(
         id: ManifestItemId.generate(),
         context: encodingContext,
         element: element,
@@ -509,7 +509,7 @@ class LibraryManifestBuilder {
     }
 
     var item = _getOrBuildElementItem(element, () {
-      return InstanceItemSetterItem.fromElement(
+      return SetterItem.fromElement(
         id: ManifestItemId.generate(),
         context: encodingContext,
         element: element,
@@ -530,7 +530,7 @@ class LibraryManifestBuilder {
     }
 
     var item = _getOrBuildElementItem(element, () {
-      return InterfaceItemConstructorItem.fromElement(
+      return ConstructorItem.fromElement(
         id: ManifestItemId.generate(),
         context: encodingContext,
         element: element,
@@ -657,12 +657,12 @@ class LibraryManifestBuilder {
 
   void _addTopLevelGetter({
     required EncodeContext encodingContext,
-    required Map<LookupName, TopLevelGetterItem> newItems,
+    required Map<LookupName, GetterItem> newItems,
     required GetterElementImpl element,
     required LookupName lookupName,
   }) {
     var item = _getOrBuildElementItem(element, () {
-      return TopLevelGetterItem.fromElement(
+      return GetterItem.fromElement(
         id: ManifestItemId.generate(),
         context: encodingContext,
         element: element,
@@ -673,12 +673,12 @@ class LibraryManifestBuilder {
 
   void _addTopLevelSetter({
     required EncodeContext encodingContext,
-    required Map<LookupName, TopLevelSetterItem> newItems,
+    required Map<LookupName, SetterItem> newItems,
     required SetterElementImpl element,
     required LookupName lookupName,
   }) {
     var item = _getOrBuildElementItem(element, () {
-      return TopLevelSetterItem.fromElement(
+      return SetterItem.fromElement(
         id: ManifestItemId.generate(),
         context: encodingContext,
         element: element,
@@ -756,8 +756,8 @@ class LibraryManifestBuilder {
       var newExtensionTypeItems = <LookupName, ExtensionTypeItem>{};
       var newMixinItems = <LookupName, MixinItem>{};
       var newTypeAliasItems = <LookupName, TypeAliasItem>{};
-      var newTopLevelGetters = <LookupName, TopLevelGetterItem>{};
-      var newTopLevelSetters = <LookupName, TopLevelSetterItem>{};
+      var newTopLevelGetters = <LookupName, GetterItem>{};
+      var newTopLevelSetters = <LookupName, SetterItem>{};
       var newTopLevelFunctions = <LookupName, TopLevelFunctionItem>{};
       var newTopLevelVariables = <LookupName, TopLevelVariableItem>{};
 
@@ -1446,7 +1446,7 @@ class _LibraryMatch {
     }
 
     var item = instanceItem.declaredGetters[lookupName];
-    if (item is! InstanceItemGetterItem) {
+    if (item == null) {
       return false;
     }
 
@@ -1470,7 +1470,7 @@ class _LibraryMatch {
     }
 
     var item = instanceItem.declaredMethods[lookupName];
-    if (item is! InstanceItemMethodItem) {
+    if (item == null) {
       return false;
     }
 
@@ -1494,7 +1494,7 @@ class _LibraryMatch {
     }
 
     var item = instanceItem.declaredSetters[lookupName];
-    if (item is! InstanceItemSetterItem) {
+    if (item == null) {
       return false;
     }
 
@@ -1518,7 +1518,7 @@ class _LibraryMatch {
     }
 
     var item = interfaceItem.declaredConstructors[lookupName];
-    if (item is! InterfaceItemConstructorItem) {
+    if (item == null) {
       return false;
     }
 

pkg/analyzer/lib/src/fine/manifest_context.dart

@@ -361,7 +361,7 @@ extension LinkedElementFactoryExtension on LinkedElementFactory {
 
     // SAFETY: if we can reference the element, it has a name.
     var topLevelName = topLevelElement.lookupName!.asLookupName;
-    TopLevelItem? topLevelItem;
+    ManifestItem? topLevelItem;
     switch (topLevelElement) {
       case ClassElement():
         topLevelItem = manifest.declaredClasses[topLevelName];