[cfe] Report errors on private fields in records

Closes #50144

Change-Id: I7cbf2fd30773269b5f839299f948da719f3eecc4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/263781
Auto-Submit: Chloe Stefantsova <[email protected]>
Commit-Queue: Chloe Stefantsova <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>

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

@@ -10162,6 +10162,16 @@ const MessageCode messagePrivateNamedParameter = const MessageCode(
     analyzerCodes: <String>["PRIVATE_OPTIONAL_PARAMETER"],
     problemMessage: r"""An optional named parameter can't start with '_'.""");
 
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Null> codeRecordFieldsCantBePrivate =
+    messageRecordFieldsCantBePrivate;
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const MessageCode messageRecordFieldsCantBePrivate = const MessageCode(
+    "RecordFieldsCantBePrivate",
+    analyzerCodes: <String>["INVALID_FIELD_NAME"],
+    problemMessage: r"""Record field names can't be private.""");
+
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeRecordLiteralOnePositionalFieldNoTrailingComma =
     messageRecordLiteralOnePositionalFieldNoTrailingComma;

pkg/front_end/lib/src/fasta/builder/record_type_builder.dart

@@ -10,6 +10,7 @@ import 'package:kernel/src/unaliasing.dart';
 import '../fasta_codes.dart'
     show
         messageObjectMemberNameUsedForRecordField,
+        messageRecordFieldsCantBePrivate,
         messageSupertypeIsFunction,
         noLength,
         templateDuplicatedRecordTypeFieldName,
@@ -145,6 +146,12 @@ abstract class RecordTypeBuilder extends TypeBuilder {
         positionalEntries.add(type);
         String? fieldName = field.name;
         if (fieldName != null) {
+          if (fieldName.startsWith("_")) {
+            library.addProblem(messageRecordFieldsCantBePrivate,
+                field.charOffset, fieldName.length, fileUri);
+            hasErrors = true;
+            continue;
+          }
           RecordTypeFieldBuilder? existingField = fieldsMap[fieldName];
           if (existingField != null) {
             library.addProblem(
@@ -159,6 +166,7 @@ abstract class RecordTypeBuilder extends TypeBuilder {
                           fileUri, existingField.charOffset, fieldName.length)
                 ]);
             hasErrors = true;
+            continue;
           } else {
             fieldsMap[fieldName] = field;
           }
@@ -186,6 +194,12 @@ abstract class RecordTypeBuilder extends TypeBuilder {
           hasErrors = true;
           continue;
         }
+        if (name.startsWith("_")) {
+          library.addProblem(messageRecordFieldsCantBePrivate, field.charOffset,
+              name.length, fileUri);
+          hasErrors = true;
+          continue;
+        }
         RecordTypeFieldBuilder? existingField = fieldsMap[name];
         if (existingField != null) {
           library.addProblem(

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

@@ -4231,6 +4231,10 @@ class BodyBuilder extends StackListenerImpl
                 element.name.length,
                 uri);
           }
+          if (element.name.startsWith("_")) {
+            libraryBuilder.addProblem(fasta.messageRecordFieldsCantBePrivate,
+                element.fileOffset, element.name.length, uri);
+          }
           namedElements ??= {};
           NamedExpression? existingExpression = namedElements[element.name];
           if (existingExpression != null) {

pkg/front_end/messages.yaml

@@ -5947,3 +5947,10 @@ NameNotFoundInRecordNameGet:
 
 ObjectMemberNameUsedForRecordField:
   problemMessage: "Record field names can't be the same as a member from 'Object'."
+
+RecordFieldsCantBePrivate:
+  problemMessage: "Record field names can't be private."
+  analyzerCode: INVALID_FIELD_NAME
+  experiments: records
+  script: |
+    foo() => (_bar: 1);

pkg/front_end/testcases/records/private_field_names.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2022, 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.
+
+(int _foo,) foo1() => throw 0; // Error.
+({int _foo}) foo2() => throw 0; // Error.
+foo3() => (_foo: 1); // Error.
+
+main() {}

pkg/front_end/testcases/records/private_field_names.dart.strong.expect

@@ -0,0 +1,26 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/records/private_field_names.dart:5:6: Error: Record field names can't be private.
+// (int _foo,) foo1() => throw 0; // Error.
+//      ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:6:7: Error: Record field names can't be private.
+// ({int _foo}) foo2() => throw 0; // Error.
+//       ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:7:12: Error: Record field names can't be private.
+// foo3() => (_foo: 1); // Error.
+//            ^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+static method foo1() → invalid-type
+  return throw 0;
+static method foo2() → invalid-type
+  return throw 0;
+static method foo3() → dynamic
+  return ({_foo: 1});
+static method main() → dynamic {}

pkg/front_end/testcases/records/private_field_names.dart.strong.transformed.expect

@@ -0,0 +1,31 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/records/private_field_names.dart:5:6: Error: Record field names can't be private.
+// (int _foo,) foo1() => throw 0; // Error.
+//      ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:6:7: Error: Record field names can't be private.
+// ({int _foo}) foo2() => throw 0; // Error.
+//       ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:7:12: Error: Record field names can't be private.
+// foo3() => (_foo: 1); // Error.
+//            ^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+static method foo1() → invalid-type
+  return throw 0;
+static method foo2() → invalid-type
+  return throw 0;
+static method foo3() → dynamic
+  return ({_foo: 1});
+static method main() → dynamic {}
+
+
+Extra constant evaluation status:
+Evaluated: RecordLiteral @ org-dartlang-testcase:///private_field_names.dart:7:11 -> RecordConstant(const ({_foo: 1}))
+Extra constant evaluation: evaluated: 3, effectively constant: 1

pkg/front_end/testcases/records/private_field_names.dart.textual_outline.expect

@@ -0,0 +1,4 @@
+(int _foo,) foo1() => throw 0;
+({int _foo}) foo2() => throw 0;
+foo3() => (_foo: 1);
+main() {}

pkg/front_end/testcases/records/private_field_names.dart.weak.expect

@@ -0,0 +1,26 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/records/private_field_names.dart:5:6: Error: Record field names can't be private.
+// (int _foo,) foo1() => throw 0; // Error.
+//      ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:6:7: Error: Record field names can't be private.
+// ({int _foo}) foo2() => throw 0; // Error.
+//       ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:7:12: Error: Record field names can't be private.
+// foo3() => (_foo: 1); // Error.
+//            ^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+static method foo1() → invalid-type
+  return throw 0;
+static method foo2() → invalid-type
+  return throw 0;
+static method foo3() → dynamic
+  return ({_foo: 1});
+static method main() → dynamic {}

pkg/front_end/testcases/records/private_field_names.dart.weak.modular.expect

@@ -0,0 +1,26 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/records/private_field_names.dart:5:6: Error: Record field names can't be private.
+// (int _foo,) foo1() => throw 0; // Error.
+//      ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:6:7: Error: Record field names can't be private.
+// ({int _foo}) foo2() => throw 0; // Error.
+//       ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:7:12: Error: Record field names can't be private.
+// foo3() => (_foo: 1); // Error.
+//            ^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+static method foo1() → invalid-type
+  return throw 0;
+static method foo2() → invalid-type
+  return throw 0;
+static method foo3() → dynamic
+  return ({_foo: 1});
+static method main() → dynamic {}

pkg/front_end/testcases/records/private_field_names.dart.weak.outline.expect

@@ -0,0 +1,22 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/records/private_field_names.dart:5:6: Error: Record field names can't be private.
+// (int _foo,) foo1() => throw 0; // Error.
+//      ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:6:7: Error: Record field names can't be private.
+// ({int _foo}) foo2() => throw 0; // Error.
+//       ^^^^
+//
+import self as self;
+
+static method foo1() → invalid-type
+  ;
+static method foo2() → invalid-type
+  ;
+static method foo3() → dynamic
+  ;
+static method main() → dynamic
+  ;

pkg/front_end/testcases/records/private_field_names.dart.weak.transformed.expect

@@ -0,0 +1,31 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/records/private_field_names.dart:5:6: Error: Record field names can't be private.
+// (int _foo,) foo1() => throw 0; // Error.
+//      ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:6:7: Error: Record field names can't be private.
+// ({int _foo}) foo2() => throw 0; // Error.
+//       ^^^^
+//
+// pkg/front_end/testcases/records/private_field_names.dart:7:12: Error: Record field names can't be private.
+// foo3() => (_foo: 1); // Error.
+//            ^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+static method foo1() → invalid-type
+  return throw 0;
+static method foo2() → invalid-type
+  return throw 0;
+static method foo3() → dynamic
+  return ({_foo: 1});
+static method main() → dynamic {}
+
+
+Extra constant evaluation status:
+Evaluated: RecordLiteral @ org-dartlang-testcase:///private_field_names.dart:7:11 -> RecordConstant(const ({_foo: 1}))
+Extra constant evaluation: evaluated: 3, effectively constant: 1

pkg/front_end/testcases/textual_outline.status

@@ -151,6 +151,7 @@ records/duplicated_name_errors: FormatterCrash
 records/issue50132: FormatterCrash
 records/issue50133: FormatterCrash
 records/null_shorting: FormatterCrash
+records/private_field_names: FormatterCrash
 records/record_literal_errors: FormatterCrash
 records/record_type: FormatterCrash
 records/record_type_errors: FormatterCrash