Fine. Support for duplicate class members.

Change-Id: Id574d8a8a2a77b675d0b744e37fac137827ab36b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/423080
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

Author: scheglov

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

@@ -260,6 +260,10 @@ class LibraryManifestBuilder {
       return;
     }
 
+    if (instanceItem.replaceDuplicate(lookupName)) {
+      return;
+    }
+
     var item = _getOrBuildElementItem(element, () {
       return InstanceItemGetterItem.fromElement(
         id: ManifestItemId.generate(),
@@ -270,33 +274,6 @@ class LibraryManifestBuilder {
     instanceItem.declaredMembers[lookupName] = item;
   }
 
-  void _addInstanceElementInstanceExecutable({
-    required EncodeContext encodingContext,
-    required InstanceItem instanceItem,
-    required ExecutableElementImpl2 element,
-  }) {
-    switch (element) {
-      case GetterElementImpl():
-        _addInstanceElementGetter(
-          encodingContext: encodingContext,
-          instanceItem: instanceItem,
-          element: element,
-        );
-      case MethodElementImpl2():
-        _addInstanceElementMethod(
-          encodingContext: encodingContext,
-          instanceItem: instanceItem,
-          element: element,
-        );
-      case SetterElementImpl():
-        _addInstanceElementSetter(
-          encodingContext: encodingContext,
-          instanceItem: instanceItem,
-          element: element,
-        );
-    }
-  }
-
   void _addInstanceElementMethod({
     required EncodeContext encodingContext,
     required InstanceItem instanceItem,
@@ -307,6 +284,10 @@ class LibraryManifestBuilder {
       return;
     }
 
+    if (instanceItem.replaceDuplicate(lookupName)) {
+      return;
+    }
+
     var item = _getOrBuildElementItem(element, () {
       return InstanceItemMethodItem.fromElement(
         id: ManifestItemId.generate(),
@@ -327,6 +308,10 @@ class LibraryManifestBuilder {
       return;
     }
 
+    if (instanceItem.replaceDuplicate(lookupName)) {
+      return;
+    }
+
     var item = _getOrBuildElementItem(element, () {
       return InstanceItemSetterItem.fromElement(
         id: ManifestItemId.generate(),
@@ -398,17 +383,32 @@ class LibraryManifestBuilder {
     required InterfaceElementImpl2 interfaceElement,
     required InterfaceItem interfaceItem,
   }) {
-    var inheritance = interfaceElement.inheritanceManager;
-    var map = inheritance.getInterface2(interfaceElement).map2;
-    for (var entry in map.entries) {
-      var executable = entry.value;
-      if (executable.enclosingElement2 == interfaceElement) {
-        // SAFETY: declared in the element are always impl.
-        executable as ExecutableElementImpl2;
-        _addInstanceElementInstanceExecutable(
+    for (var getter in interfaceElement.getters2) {
+      if (!getter.isStatic) {
+        _addInstanceElementGetter(
+          encodingContext: encodingContext,
+          instanceItem: interfaceItem,
+          element: getter,
+        );
+      }
+    }
+
+    for (var method in interfaceElement.methods2) {
+      if (!method.isStatic) {
+        _addInstanceElementMethod(
+          encodingContext: encodingContext,
+          instanceItem: interfaceItem,
+          element: method,
+        );
+      }
+    }
+
+    for (var setter in interfaceElement.setters2) {
+      if (!setter.isStatic) {
+        _addInstanceElementSetter(
           encodingContext: encodingContext,
           instanceItem: interfaceItem,
-          element: executable,
+          element: setter,
         );
       }
     }

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

@@ -85,6 +85,17 @@ sealed class InstanceItem<E extends InstanceElementImpl2>
     return declaredMembers[name]?.id;
   }
 
+  /// If there is already a declared member with [name], replace it with a
+  /// fresh instance of [InstanceItemDuplicateItem] and return `true`.
+  /// Otherwise return `false`.
+  bool replaceDuplicate(LookupName name) {
+    if (declaredMembers.containsKey(name)) {
+      declaredMembers[name] = InstanceItemDuplicateItem();
+      return true;
+    }
+    return false;
+  }
+
   @override
   void write(BufferedSink sink) {
     super.write(sink);
@@ -106,6 +117,54 @@ sealed class InstanceItem<E extends InstanceElementImpl2>
   }
 }
 
+/// Placeholder for a name that has duplicate declared member.
+/// It is always given a new ID.
+class InstanceItemDuplicateItem
+    extends InstanceItemMemberItem<ExecutableElementImpl2> {
+  factory InstanceItemDuplicateItem() {
+    return InstanceItemDuplicateItem._(
+      id: ManifestItemId.generate(),
+      metadata: ManifestMetadata(annotations: []),
+      isStatic: false,
+    );
+  }
+
+  factory InstanceItemDuplicateItem.read(SummaryDataReader reader) {
+    return InstanceItemDuplicateItem._(
+      id: ManifestItemId.read(reader),
+      metadata: ManifestMetadata.read(reader),
+      isStatic: reader.readBool(),
+    );
+  }
+
+  InstanceItemDuplicateItem._({
+    required super.id,
+    required super.metadata,
+    required super.isStatic,
+  });
+
+  @override
+  bool match(MatchContext context, ExecutableElementImpl2 element) {
+    super.match(context, element); // we ignore it
+    // Duplicate items don't have any specific information, they are just
+    // a flag, that previously the same name was declared twice. So, there is
+    // no way to meaningfully match them. We always return `false`, and
+    // build a new item (and ID) for this name.
+    //
+    // The reason is that we don't want to prefer first or last duplicated
+    // element, we just wait until there is no error. And once it is fixed,
+    // we will build the actual item, with a new ID, and recompute all uses
+    // once again.
+    return false;
+  }
+
+  @override
+  void write(BufferedSink sink) {
+    sink.writeEnum(_ManifestItemKind2.instanceDuplicate);
+    super.write(sink);
+  }
+}
+
 class InstanceItemGetterItem extends InstanceItemMemberItem<GetterElementImpl> {
   final ManifestType returnType;
   final ManifestNode? constInitializer;
@@ -186,6 +245,8 @@ sealed class InstanceItemMemberItem<E extends ExecutableElementImpl2>
       SummaryDataReader reader) {
     var kind = reader.readEnum(_ManifestItemKind2.values);
     switch (kind) {
+      case _ManifestItemKind2.instanceDuplicate:
+        return InstanceItemDuplicateItem.read(reader);
       case _ManifestItemKind2.instanceGetter:
         return InstanceItemGetterItem.read(reader);
       case _ManifestItemKind2.instanceMethod:
@@ -770,6 +831,7 @@ enum _ManifestItemKind {
 }
 
 enum _ManifestItemKind2 {
+  instanceDuplicate,
   instanceGetter,
   instanceMethod,
   instanceSetter,