Add support for macros in override information

Change-Id: I308fd21becac53a6ad535b508749a119f8816709
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/353781
Reviewed-by: Keerti Parthasarathy <keertip@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/computer/computer_overrides.dart

@@ -136,6 +136,7 @@ class _OverriddenElementsFinder {
 
   /// Add the [OverriddenElements] for this element.
   OverriddenElements find() {
+    _class = _class.augmented?.declaration ?? _class;
     _visited.clear();
     _addSuperOverrides(_class, withThisType: false);
     _visited.clear();

pkg/analysis_server/test/analysis/notification_overrides_test.dart

@@ -7,6 +7,7 @@ import 'dart:async';
 import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_constants.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
+import 'package:analyzer/file_system/file_system.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -60,6 +61,14 @@ class AnalysisNotificationOverridesTest extends PubPackageAnalysisServerTest {
     expect(member!.element.location!.offset, offset);
   }
 
+  /// Asserts that there is an overridden superclass [OverriddenMember] at the
+  /// offset of [search] in [override].
+  void assertHasSuperElementInFile(File file, String search) {
+    var offset = offsetInFile(file, search);
+    var member = overrideObject.superclassMember;
+    expect(member!.element.location!.offset, offset);
+  }
+
   /// Asserts that there are no overridden members from interfaces.
   void assertNoInterfaceMembers() {
     expect(overrideObject.interfaceMembers, isNull);
@@ -522,6 +531,50 @@ class C extends B {
     assertNoInterfaceMembers();
   }
 
+  Future<void> test_class_super_method_overriddenFromExtension() async {
+    var augmentation = newFile('$testPackageLibPath/a.dart', '''
+library augment 'test.dart';
+
+augment class A {
+  m() {} // in A
+}
+''');
+    addTestFile('''
+import augment 'a.dart';
+
+class A {}
+class B extends A {
+  m() {} // in B
+}
+''');
+    await prepareOverrides();
+    assertHasOverride('m() {} // in B');
+    assertHasSuperElementInFile(augmentation, 'm() {} // in A');
+    assertNoInterfaceMembers();
+  }
+
+  Future<void> test_class_super_method_overrideFromExtension() async {
+    var augmented = newFile('$testPackageLibPath/b.dart', '''
+import augment 'test.dart';
+
+class A {
+  m() {} // in A
+}
+class B extends A {}
+''');
+    addTestFile('''
+library augment 'b.dart';
+
+augment class B {
+  m() {} // in B
+}
+''');
+    await prepareOverrides();
+    assertHasOverride('m() {} // in B');
+    assertHasSuperElementInFile(augmented, 'm() {} // in A');
+    assertNoInterfaceMembers();
+  }
+
   Future<void> test_class_super_method_privateByPrivate() async {
     addTestFile('''
 class A {