[parser][CFE][analyzer] Function is builtIn keyword

This CL makes `Function` a builtIn keyword instead of a `pseudo` keyword.

See also (and fixes):
#45703
#45704
#45705
#49197

This undoes https://dart-review.googlesource.com/c/sdk/+/195761

This is ~a merge of https://dart-review.googlesource.com/c/sdk/+/195906
and https://dart-review.googlesource.com/c/sdk/+/200080

Change-Id: I8bfee6976d43819fa355de99b3b2429eb67a7cdd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/249484
Reviewed-by: Johnni Winther <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Jens Johansen <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: jensjoha

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -5010,15 +5010,6 @@ const MessageCode messageForInLoopWithConstVariable = const MessageCode(
     problemMessage: r"""A for-in loop-variable can't be 'const'.""",
     correctionMessage: r"""Try removing the 'const' modifier.""");
 
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Code<Null> codeFunctionAsTypeParameter = messageFunctionAsTypeParameter;
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const MessageCode messageFunctionAsTypeParameter = const MessageCode(
-    "FunctionAsTypeParameter",
-    problemMessage:
-        r"""'Function' is a built-in identifier, could not used as a type identifier.""");
-
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeFunctionTypeDefaultValue = messageFunctionTypeDefaultValue;
 
@@ -5040,30 +5031,6 @@ const MessageCode messageFunctionTypedParameterVar = const MessageCode(
         r"""Function-typed parameters can't specify 'const', 'final' or 'var' in place of a return type.""",
     correctionMessage: r"""Try replacing the keyword with a return type.""");
 
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Template<
-    Message Function(String name)> templateFunctionUsedAsDec = const Template<
-        Message Function(String name)>(
-    problemMessageTemplate:
-        r"""'Function' is a built-in identifier, could not used as a #name name.""",
-    withArguments: _withArgumentsFunctionUsedAsDec);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Code<Message Function(String name)> codeFunctionUsedAsDec =
-    const Code<Message Function(String name)>(
-  "FunctionUsedAsDec",
-);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-Message _withArgumentsFunctionUsedAsDec(String name) {
-  if (name.isEmpty) throw 'No name provided';
-  name = demangleMixinApplicationName(name);
-  return new Message(codeFunctionUsedAsDec,
-      problemMessage:
-          """'Function' is a built-in identifier, could not used as a ${name} name.""",
-      arguments: {'name': name});
-}
-
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeGeneratorReturnsValue = messageGeneratorReturnsValue;
 

pkg/_fe_analyzer_shared/lib/src/parser/stack_listener.dart

@@ -9,6 +9,7 @@ import '../messages/codes.dart'
         Code,
         LocatedMessage,
         Message,
+        codeBuiltInIdentifierInDeclaration,
         codeCatchSyntaxExtraParameters,
         codeNativeClauseShouldBeAnnotation,
         templateInternalProblemStackNotEmpty,
@@ -216,6 +217,8 @@ abstract class StackListener extends Listener {
   @override
   Uri get uri;
 
+  Uri get importUri;
+
   void discard(int n) {
     for (int i = 0; i < n; i++) {
       pop();
@@ -498,6 +501,10 @@ abstract class StackListener extends Listener {
     } else if (code == codeCatchSyntaxExtraParameters) {
       // Ignored. This error is handled by the BodyBuilder.
       return true;
+    } else if (code == codeBuiltInIdentifierInDeclaration) {
+      if (importUri.isScheme("dart")) return true;
+      if (uri.isScheme("org-dartlang-sdk")) return true;
+      return false;
     } else {
       return false;
     }

pkg/_fe_analyzer_shared/lib/src/parser/type_info.dart

@@ -138,6 +138,7 @@ bool isValidTypeReference(Token token) {
     return type.isPseudo ||
         (type.isBuiltIn && optional('.', token.next!)) ||
         (identical(value, 'dynamic')) ||
+        (identical(value, 'Function')) ||
         (identical(value, 'void'));
   }
   return false;

pkg/_fe_analyzer_shared/lib/src/scanner/token.dart

@@ -197,7 +197,7 @@ class Keyword extends TokenType {
   static const Keyword FOR = const Keyword("for", "FOR", KeywordStyle.reserved);
 
   static const Keyword FUNCTION =
-      const Keyword("Function", "FUNCTION", KeywordStyle.pseudo);
+      const Keyword("Function", "FUNCTION", KeywordStyle.builtIn);
 
   static const Keyword GET = const Keyword("get", "GET", KeywordStyle.builtIn);
 

pkg/analysis_server/lib/src/services/correction/error_fix_status.yaml

@@ -1228,10 +1228,6 @@ HintCode.DEPRECATED_EXTENDS_FUNCTION:
   status: needsFix
   notes: |-
     The fix is to remove `Function` from where it's referenced.
-HintCode.DEPRECATED_FUNCTION_CLASS_DECLARATION:
-  status: noFix
-  notes: |-
-    The fix is to rename the class, which can't be done as a fix.
 HintCode.DEPRECATED_IMPLEMENTS_FUNCTION:
   status: needsFix
   notes: |-

pkg/analyzer/lib/error/error.dart

@@ -555,7 +555,6 @@ const List<ErrorCode> errorCodeValues = [
   HintCode.DEAD_CODE_ON_CATCH_SUBTYPE,
   HintCode.DEPRECATED_EXPORT_USE,
   HintCode.DEPRECATED_EXTENDS_FUNCTION,
-  HintCode.DEPRECATED_FUNCTION_CLASS_DECLARATION,
   HintCode.DEPRECATED_IMPLEMENTS_FUNCTION,
   HintCode.DEPRECATED_MEMBER_USE,
   HintCode.DEPRECATED_MEMBER_USE_FROM_SAME_PACKAGE,

pkg/analyzer/lib/src/dart/element/element.dart

@@ -140,6 +140,12 @@ abstract class AbstractClassElementImpl extends _ExistingElementImpl
     return name == '_Enum' && library.isDartCore;
   }
 
+  /// Return `true` if this class represents the class 'Function' defined in the
+  /// dart:core library.
+  bool get isDartCoreFunctionImpl {
+    return name == 'Function' && library.isDartCore;
+  }
+
   @override
   bool get isDartCoreObject => false;
 

pkg/analyzer/lib/src/dart/error/hint_codes.g.dart

@@ -111,13 +111,6 @@ class HintCode extends AnalyzerErrorCode {
     uniqueName: 'DEPRECATED_EXTENDS_FUNCTION',
   );
 
-  ///  Users should not create a class named `Function` anymore.
-  static const HintCode DEPRECATED_FUNCTION_CLASS_DECLARATION = HintCode(
-    'DEPRECATED_FUNCTION_CLASS_DECLARATION',
-    "Declaring a class named 'Function' is deprecated.",
-    correctionMessage: "Try renaming the class.",
-  );
-
   ///  No parameters.
   static const HintCode DEPRECATED_IMPLEMENTS_FUNCTION = HintCode(
     'DEPRECATED_SUBTYPE_OF_FUNCTION',

pkg/analyzer/lib/src/fasta/ast_builder.dart

@@ -7,6 +7,7 @@ import 'package:_fe_analyzer_shared/src/messages/codes.dart'
         LocatedMessage,
         Message,
         MessageCode,
+        codeBuiltInIdentifierInDeclaration,
         messageAbstractClassMember,
         messageAbstractLateField,
         messageAbstractStaticField,
@@ -205,6 +206,9 @@ class AstBuilder extends StackListener {
     }
   }
 
+  @override
+  Uri get importUri => uri;
+
   @override
   void addProblem(Message message, int charOffset, int length,
       {bool wasHandled = false, List<LocatedMessage>? context}) {
@@ -3782,6 +3786,10 @@ class AstBuilder extends StackListener {
     /// TODO(danrubel): Ignore this error until we deprecate `native` support.
     if (message == messageNativeClauseShouldBeAnnotation && allowNativeClause) {
       return;
+    } else if (message.code == codeBuiltInIdentifierInDeclaration) {
+      // Allow e.g. 'class Function' in sdk.
+      if (importUri.isScheme("dart")) return;
+      if (uri.isScheme("org-dartlang-sdk")) return;
     }
     debugEvent("Error: ${message.problemMessage}");
     if (message.code.analyzerCodes == null && startToken is ErrorToken) {

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

@@ -426,8 +426,10 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
 
       List<ClassMember> members = node.members;
       _duplicateDefinitionVerifier.checkClass(node);
-      _checkForBuiltInIdentifierAsName(
-          node.name, CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_NAME);
+      if (!element.isDartCoreFunctionImpl) {
+        _checkForBuiltInIdentifierAsName(
+            node.name, CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_NAME);
+      }
       _checkForConflictingClassTypeVariableErrorCodes();
       var superclass = node.extendsClause?.superclass;
       var implementsClause = node.implementsClause;
@@ -1660,11 +1662,6 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
     var implementsClause = node.implementsClause;
     var withClause = node.withClause;
 
-    if (node.name.name == "Function") {
-      errorReporter.reportErrorForNode(
-          HintCode.DEPRECATED_FUNCTION_CLASS_DECLARATION, node.name);
-    }
-
     if (extendsClause != null) {
       var superElement = extendsClause.superclass.name.staticElement;
       if (superElement != null && superElement.name == "Function") {

pkg/analyzer/messages.yaml

@@ -17669,10 +17669,6 @@ HintCode:
         }
       }
       ```
-  DEPRECATED_FUNCTION_CLASS_DECLARATION:
-    problemMessage: "Declaring a class named 'Function' is deprecated."
-    correctionMessage: Try renaming the class.
-    comment: Users should not create a class named `Function` anymore.
   DEPRECATED_EXPORT_USE:
     problemMessage: "The ability to import '{0}' indirectly has been deprecated."
     correctionMessage: "Try importing '{0}' directly."

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

@@ -15,7 +15,7 @@ main() {
 
 @reflectiveTest
 class BuiltInIdentifierAsExtensionNameTest extends PubPackageResolutionTest {
-  test_error_builtInIdentifierAsExtensionName() async {
+  test_as() async {
     await assertErrorsInCode(
       r'''
 extension as on Object {}
@@ -26,4 +26,16 @@ extension as on Object {}
       ],
     );
   }
+
+  test_Function() async {
+    await assertErrorsInCode(
+      r'''
+extension Function on Object {}
+''',
+      [
+        error(
+            CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_EXTENSION_NAME, 10, 8),
+      ],
+    );
+  }
 }

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

@@ -15,9 +15,18 @@ main() {
 
 @reflectiveTest
 class BuiltInIdentifierAsPrefixNameTest extends PubPackageResolutionTest {
-  test_builtInIdentifierAsPrefixName() async {
+  test_abstract() async {
     await assertErrorsInCode('''
 import 'dart:async' as abstract;
+''', [
+      error(HintCode.UNUSED_IMPORT, 7, 12),
+      error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_PREFIX_NAME, 23, 8),
+    ]);
+  }
+
+  test_Function() async {
+    await assertErrorsInCode('''
+import 'dart:async' as Function;
 ''', [
       error(HintCode.UNUSED_IMPORT, 7, 12),
       error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_PREFIX_NAME, 23, 8),

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

@@ -15,14 +15,22 @@ main() {
 
 @reflectiveTest
 class BuiltInIdentifierAsTypeNameTest extends PubPackageResolutionTest {
-  test_class() async {
+  test_class_as() async {
     await assertErrorsInCode('''
 class as {}
 ''', [
       error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_NAME, 6, 2),
     ]);
   }
 
+  test_class_Function() async {
+    await assertErrorsInCode('''
+class Function {}
+''', [
+      error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_NAME, 6, 8),
+    ]);
+  }
+
   test_enum() async {
     await assertErrorsInCode('''
 enum as {
@@ -33,14 +41,22 @@ enum as {
     ]);
   }
 
-  test_mixin() async {
+  test_mixin_as() async {
     await assertErrorsInCode('''
 mixin as {}
 ''', [
       error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_NAME, 6, 2),
     ]);
   }
 
+  test_mixin_Function() async {
+    await assertErrorsInCode('''
+mixin Function {}
+''', [
+      error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_NAME, 6, 8),
+    ]);
+  }
+
   test_mixin_OK_on() async {
     await assertNoErrorsInCode(r'''
 class A {}

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

@@ -16,7 +16,7 @@ main() {
 @reflectiveTest
 class BuiltInIdentifierAsTypeParameterNameTest
     extends PubPackageResolutionTest {
-  test_class() async {
+  test_class_as() async {
     await assertErrorsInCode('''
 class A<as> {}
 ''', [
@@ -25,7 +25,16 @@ class A<as> {}
     ]);
   }
 
-  test_extension() async {
+  test_class_Function() async {
+    await assertErrorsInCode('''
+class A<Function> {}
+''', [
+      error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_PARAMETER_NAME, 8,
+          8),
+    ]);
+  }
+
+  test_extension_as() async {
     await assertErrorsInCode('''
 extension <as> on List {}
 ''', [
@@ -34,7 +43,7 @@ extension <as> on List {}
     ]);
   }
 
-  test_function() async {
+  test_function_as() async {
     await assertErrorsInCode('''
 void f<as>() {}
 ''', [

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

@@ -35,7 +35,16 @@ typedef void as();
     ]);
   }
 
-  test_typedef_generic() async {
+  test_typedef_classic_as() async {
+    await assertErrorsInCode(r'''
+typedef void as();
+''', [
+      error(ParserErrorCode.EXPECTED_IDENTIFIER_BUT_GOT_KEYWORD, 13, 2),
+      error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPEDEF_NAME, 13, 2),
+    ]);
+  }
+
+  test_typedef_generic_as() async {
     await assertErrorsInCode(r'''
 typedef as = void Function();
 ''', [
@@ -44,12 +53,21 @@ typedef as = void Function();
     ]);
   }
 
-  test_typedef_interfaceType() async {
+  test_typedef_interfaceType_as() async {
     await assertErrorsInCode(r'''
 typedef as = List<int>;
 ''', [
       error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPEDEF_NAME, 8, 2),
       error(ParserErrorCode.EXPECTED_IDENTIFIER_BUT_GOT_KEYWORD, 8, 2)
     ]);
   }
+
+  test_typedef_interfaceType_Function() async {
+    await assertErrorsInCode(r'''
+typedef Function = List<int>;
+''', [
+      error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPEDEF_NAME, 8, 8),
+      error(ParserErrorCode.EXPECTED_IDENTIFIER_BUT_GOT_KEYWORD, 8, 8)
+    ]);
+  }
 }

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

@@ -2,7 +2,7 @@
 // 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/dart/error/hint_codes.dart';
+import 'package:analyzer/src/error/codes.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../dart/resolution/context_collection_resolution.dart';
@@ -28,7 +28,7 @@ class A extends Function {}
 class Function {}
 class A extends Function {}
 ''', [
-      error(HintCode.DEPRECATED_FUNCTION_CLASS_DECLARATION, 6, 8),
+      error(CompileTimeErrorCode.BUILT_IN_IDENTIFIER_AS_TYPE_NAME, 6, 8),
       error(HintCode.DEPRECATED_EXTENDS_FUNCTION, 34, 8),
     ]);
   }