Analyzer: Remove error on class-used-as-mixin referencing super

Fixes https://github.com/dart-lang/sdk/issues/34806

Change-Id: I1cfd0b9c0699734b172aa62f7a04ab533a6cd03f
Fixed: 34806
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/151099
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/test/integration/analysis/error_test.dart

@@ -51,37 +51,6 @@ main() {
     });
   }
 
-  Future<void> test_super_mixins_disabled() async {
-    var pathname = sourcePath('test.dart');
-    writeFile(pathname, '''
-class Test extends Object with C {
-  void foo() {}
-}
-abstract class B {
-  void foo() {}
-}
-abstract class C extends B {
-  void bar() {
-    super.foo();
-  }
-}
-''');
-    standardAnalysisSetup();
-    await analysisFinished;
-    expect(currentAnalysisErrors[pathname], isList);
-    var errors = currentAnalysisErrors[pathname];
-    expect(errors, hasLength(2));
-    var allErrorMessages = errors.map((AnalysisError e) => e.message).toSet();
-    expect(
-        allErrorMessages,
-        contains(
-            "The class 'C' can't be used as a mixin because it extends a class other than Object."));
-    expect(
-        allErrorMessages,
-        contains(
-            "The class 'C' can't be used as a mixin because it references 'super'."));
-  }
-
   @failingTest
   Future<void> test_super_mixins_enabled() async {
     // We see errors here with the new driver (#28870).

pkg/analyzer/lib/error/error.dart

@@ -235,7 +235,6 @@ const List<ErrorCode> errorCodeValues = [
   CompileTimeErrorCode.MIXIN_INSTANTIATE,
   CompileTimeErrorCode.MIXIN_OF_DISALLOWED_CLASS,
   CompileTimeErrorCode.MIXIN_OF_NON_CLASS,
-  CompileTimeErrorCode.MIXIN_REFERENCES_SUPER,
   CompileTimeErrorCode.MIXIN_SUPER_CLASS_CONSTRAINT_DEFERRED_CLASS,
   CompileTimeErrorCode.MIXIN_SUPER_CLASS_CONSTRAINT_DISALLOWED_CLASS,
   CompileTimeErrorCode.MIXIN_SUPER_CLASS_CONSTRAINT_NON_INTERFACE,

pkg/analyzer/lib/src/error/codes.dart

@@ -4135,16 +4135,6 @@ class CompileTimeErrorCode extends AnalyzerErrorCode {
       'MIXIN_OF_NON_CLASS', "Classes can only mix in mixins and classes.",
       hasPublishedDocs: true);
 
-  /**
-   * 9 Mixins: It is a compile-time error if a declared or derived mixin refers
-   * to super.
-   */
-  static const CompileTimeErrorCode MIXIN_REFERENCES_SUPER =
-      CompileTimeErrorCode(
-          'MIXIN_REFERENCES_SUPER',
-          "The class '{0}' can't be used as a mixin because it references "
-              "'super'.");
-
   static const CompileTimeErrorCode
       MIXIN_SUPER_CLASS_CONSTRAINT_DEFERRED_CLASS = CompileTimeErrorCode(
           'MIXIN_SUPER_CLASS_CONSTRAINT_DEFERRED_CLASS',

pkg/analyzer/lib/src/generated/error_verifier.dart

@@ -1301,8 +1301,7 @@ class ErrorVerifier extends RecursiveAstVisitor<void> {
    * Verify that all classes of the given [withClause] are valid.
    *
    * See [CompileTimeErrorCode.MIXIN_CLASS_DECLARES_CONSTRUCTOR],
-   * [CompileTimeErrorCode.MIXIN_INHERITS_FROM_NOT_OBJECT], and
-   * [CompileTimeErrorCode.MIXIN_REFERENCES_SUPER].
+   * [CompileTimeErrorCode.MIXIN_INHERITS_FROM_NOT_OBJECT].
    */
   bool _checkForAllMixinErrorCodes(WithClause withClause) {
     if (withClause == null) {
@@ -1342,9 +1341,6 @@ class ErrorVerifier extends RecursiveAstVisitor<void> {
             if (_checkForMixinInheritsNotFromObject(mixinName, mixinElement)) {
               problemReported = true;
             }
-            if (_checkForMixinReferencesSuper(mixinName, mixinElement)) {
-              problemReported = true;
-            }
           }
         }
       }
@@ -3297,24 +3293,6 @@ class ErrorVerifier extends RecursiveAstVisitor<void> {
     return false;
   }
 
-  /**
-   * Verify that the given mixin does not reference 'super'. The [mixinName] is
-   * the node to report problem on. The [mixinElement] is the mixing to
-   * evaluate.
-   *
-   * See [CompileTimeErrorCode.MIXIN_REFERENCES_SUPER].
-   */
-  bool _checkForMixinReferencesSuper(
-      TypeName mixinName, ClassElement mixinElement) {
-    if (mixinElement.hasReferenceToSuper) {
-      _errorReporter.reportErrorForNode(
-          CompileTimeErrorCode.MIXIN_REFERENCES_SUPER,
-          mixinName,
-          [mixinElement.name]);
-    }
-    return false;
-  }
-
   /// Check that superclass constrains for the mixin type of [mixinName] at
   /// the [mixinIndex] position in the mixins list are satisfied by the
   /// [_enclosingClass], or a previous mixin.

pkg/analyzer/test/generated/simple_resolver_test.dart

@@ -861,15 +861,13 @@ class C = Object with A;''');
   }
 
   test_isValidMixin_super() async {
-    await assertErrorsInCode(r'''
+    await assertNoErrorsInCode(r'''
 class A {
   toString() {
     return super.toString();
   }
 }
-class C = Object with A;''', [
-      error(CompileTimeErrorCode.MIXIN_REFERENCES_SUPER, 82, 1),
-    ]);
+class C = Object with A;''');
     verifyTestResolved();
 
     var a = findElement.class_('A');

pkg/analyzer/test/src/diagnostics/mixin_references_super_test.dart

@@ -1,37 +0,0 @@
-// Copyright (c) 2019, 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:analyzer/src/error/codes.dart';
-import 'package:test_reflective_loader/test_reflective_loader.dart';
-
-import '../dart/resolution/driver_resolution.dart';
-
-main() {
-  defineReflectiveSuite(() {
-    defineReflectiveTests(MixinReferencesSuperTest);
-  });
-}
-
-@reflectiveTest
-class MixinReferencesSuperTest extends DriverResolutionTest {
-  test_mixin_references_super() async {
-    await assertErrorsInCode(r'''
-class A {
-  toString() => super.toString();
-}
-class B extends Object with A {}
-''', [
-      error(CompileTimeErrorCode.MIXIN_REFERENCES_SUPER, 74, 1),
-    ]);
-  }
-
-  test_mixin_unconstrained_references_super() async {
-    await assertNoErrorsInCode(r'''
-mixin A {
-  toString() => super.toString();
-}
-class B extends Object with A {}
-''');
-  }
-}

pkg/analyzer/test/src/diagnostics/test_all.dart

@@ -293,7 +293,6 @@ import 'mixin_inherits_from_not_object_test.dart'
 import 'mixin_of_disallowed_class_test.dart' as mixin_of_disallowed_class;
 import 'mixin_of_non_class_test.dart' as mixin_of_non_class;
 import 'mixin_on_sealed_class_test.dart' as mixin_on_sealed_class;
-import 'mixin_references_super_test.dart' as mixin_references_super;
 import 'mixin_super_class_constraint_non_interface_test.dart'
     as mixin_super_class_constraint_non_interface;
 import 'mixin_with_non_class_superclass_test.dart'
@@ -721,7 +720,6 @@ main() {
     mixin_of_disallowed_class.main();
     mixin_of_non_class.main();
     mixin_on_sealed_class.main();
-    mixin_references_super.main();
     mixin_super_class_constraint_non_interface.main();
     mixin_with_non_class_superclass.main();
     must_be_a_native_function_type.main();

tests/language/mixin/illegal_super_use_test.dart

@@ -76,14 +76,8 @@ class P2 {
 
 class C = Object with M;
 class D = Object with P0;
-//                    ^^
-// [analyzer] COMPILE_TIME_ERROR.MIXIN_REFERENCES_SUPER
 class E = Object with M, P1;
-//                       ^^
-// [analyzer] COMPILE_TIME_ERROR.MIXIN_REFERENCES_SUPER
 class F = Object with P2, M;
-//                    ^^
-// [analyzer] COMPILE_TIME_ERROR.MIXIN_REFERENCES_SUPER
 
 main() {
   var p1 = new P1();

tests/language_2/mixin/illegal_super_use_test.dart

@@ -76,14 +76,8 @@ class P2 {
 
 class C = Object with M;
 class D = Object with P0;
-//                    ^^
-// [analyzer] COMPILE_TIME_ERROR.MIXIN_REFERENCES_SUPER
 class E = Object with M, P1;
-//                       ^^
-// [analyzer] COMPILE_TIME_ERROR.MIXIN_REFERENCES_SUPER
 class F = Object with P2, M;
-//                    ^^
-// [analyzer] COMPILE_TIME_ERROR.MIXIN_REFERENCES_SUPER
 
 main() {
   var p1 = new P1();