[cfe] Handle parser recovery in extension declarations

Closes #38600
Closes #38712

Change-Id: I875c55c49253066263bfe1c9cbe97debd1e81648
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120583
Reviewed-by: Aske Simon Christensen <askesc@google.com>

Author: johnniwinther

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

@@ -39,7 +39,8 @@ export 'procedure_builder.dart'
 
 export 'function_type_builder.dart' show FunctionTypeBuilder;
 
-export 'invalid_type_builder.dart' show InvalidTypeBuilder;
+export 'invalid_type_declaration_builder.dart'
+    show InvalidTypeDeclarationBuilder;
 
 export 'library_builder.dart' show LibraryBuilder;
 

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

@@ -0,0 +1,46 @@
+// Copyright (c) 2016, 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:kernel/ast.dart' hide MapEntry;
+
+import '../problems.dart';
+import 'library_builder.dart';
+import 'nullability_builder.dart';
+import 'type_builder.dart';
+
+class FixedTypeBuilder extends TypeBuilder {
+  final DartType type;
+
+  const FixedTypeBuilder(this.type);
+
+  TypeBuilder clone(List<TypeBuilder> newTypes) => this;
+
+  Object get name => null;
+
+  NullabilityBuilder get nullabilityBuilder =>
+      new NullabilityBuilder.fromNullability(type.nullability);
+
+  String get debugName => 'FixedTypeBuilder';
+
+  StringBuffer printOn(StringBuffer buffer) {
+    buffer.write('type=${type}');
+    return buffer;
+  }
+
+  DartType build(LibraryBuilder library) => type;
+
+  Supertype buildSupertype(
+      LibraryBuilder library, int charOffset, Uri fileUri) {
+    return unhandled('buildSupertype', 'FixedTypeBuilder', charOffset, fileUri);
+  }
+
+  Supertype buildMixedInType(
+      LibraryBuilder library, int charOffset, Uri fileUri) {
+    return unhandled(
+        'buildMixedInType', 'FixedTypeBuilder', charOffset, fileUri);
+  }
+
+  TypeBuilder withNullabilityBuilder(NullabilityBuilder nullabilityBuilder) =>
+      this;
+}

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

@@ -17,10 +17,7 @@ import 'package:kernel/ast.dart'
         TypeParameter,
         TypedefType;
 
-import '../fasta_codes.dart'
-    show LocatedMessage, messageSupertypeIsFunction, noLength;
-
-import '../problems.dart' show unsupported;
+import '../fasta_codes.dart' show messageSupertypeIsFunction, noLength;
 
 import '../kernel/kernel_builder.dart'
     show
@@ -127,11 +124,6 @@ class FunctionTypeBuilder extends TypeBuilder {
     return buildSupertype(library, charOffset, fileUri);
   }
 
-  @override
-  buildInvalidType(LocatedMessage message, {List<LocatedMessage> context}) {
-    return unsupported("buildInvalidType", message.charOffset, message.uri);
-  }
-
   FunctionTypeBuilder clone(List<TypeBuilder> newTypes) {
     List<TypeVariableBuilder> clonedTypeVariables;
     if (typeVariables != null) {

pkg/front_end/lib/src/fasta/builder/invalid_type_builder.dart renamed to pkg/front_end/lib/src/fasta/builder/invalid_type_declaration_builder.dart

@@ -14,7 +14,7 @@ import '../kernel/kernel_builder.dart' show TypeBuilder, LibraryBuilder;
 
 import 'type_declaration_builder.dart';
 
-class InvalidTypeBuilder extends TypeDeclarationBuilderImpl {
+class InvalidTypeDeclarationBuilder extends TypeDeclarationBuilderImpl {
   String get debugName => "InvalidTypeBuilder";
 
   final LocatedMessage message;
@@ -23,7 +23,7 @@ class InvalidTypeBuilder extends TypeDeclarationBuilderImpl {
 
   final bool suppressMessage;
 
-  InvalidTypeBuilder(String name, this.message,
+  InvalidTypeDeclarationBuilder(String name, this.message,
       {this.context, this.suppressMessage: true})
       : super(null, 0, name, null, message.charOffset, message.uri);
 

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

@@ -9,8 +9,6 @@ import 'builder.dart'
 
 import 'package:kernel/ast.dart' show InterfaceType, Supertype;
 
-import '../fasta_codes.dart' show LocatedMessage;
-
 import '../problems.dart' show unsupported;
 
 class MixinApplicationBuilder extends TypeBuilder {
@@ -61,11 +59,6 @@ class MixinApplicationBuilder extends TypeBuilder {
     return unsupported("buildMixedInType", charOffset, fileUri);
   }
 
-  @override
-  buildInvalidType(LocatedMessage message, {List<LocatedMessage> context}) {
-    return unsupported("buildInvalidType", message.charOffset, message.uri);
-  }
-
   @override
   MixinApplicationBuilder withNullabilityBuilder(
       NullabilityBuilder nullabilityBuilder) {

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

@@ -43,7 +43,7 @@ import 'builder.dart'
 import '../kernel/kernel_builder.dart'
     show
         ClassBuilder,
-        InvalidTypeBuilder,
+        InvalidTypeDeclarationBuilder,
         LibraryBuilder,
         TypeBuilder,
         TypeDeclarationBuilder,
@@ -105,7 +105,7 @@ class NamedTypeBuilder extends TypeBuilder {
         Message message =
             templateTypeArgumentsOnTypeVariable.withArguments(typeName);
         library.addProblem(message, typeNameOffset, typeName.length, fileUri);
-        declaration = buildInvalidType(
+        declaration = buildInvalidTypeDeclarationBuilder(
             message.withLocation(fileUri, typeNameOffset, typeName.length));
       }
       return;
@@ -146,7 +146,7 @@ class NamedTypeBuilder extends TypeBuilder {
         name is Identifier ? name.endCharOffset - charOffset : flatName.length;
     Message message = template.withArguments(flatName);
     library.addProblem(message, charOffset, length, fileUri, context: context);
-    declaration = buildInvalidType(
+    declaration = buildInvalidTypeDeclarationBuilder(
         message.withLocation(fileUri, charOffset, length),
         context: context);
   }
@@ -158,8 +158,8 @@ class NamedTypeBuilder extends TypeBuilder {
       Message message = templateTypeArgumentMismatch
           .withArguments(declaration.typeVariablesCount);
       library.addProblem(message, charOffset, noLength, fileUri);
-      declaration =
-          buildInvalidType(message.withLocation(fileUri, charOffset, noLength));
+      declaration = buildInvalidTypeDeclarationBuilder(
+          message.withLocation(fileUri, charOffset, noLength));
     }
   }
 
@@ -189,11 +189,12 @@ class NamedTypeBuilder extends TypeBuilder {
     return buffer;
   }
 
-  InvalidTypeBuilder buildInvalidType(LocatedMessage message,
+  InvalidTypeDeclarationBuilder buildInvalidTypeDeclarationBuilder(
+      LocatedMessage message,
       {List<LocatedMessage> context}) {
     // TODO(ahe): Consider if it makes sense to pass a QualifiedName to
     // InvalidTypeBuilder?
-    return new InvalidTypeBuilder(
+    return new InvalidTypeDeclarationBuilder(
         flattenName(name, message.charOffset, message.uri), message,
         context: context);
   }
@@ -222,7 +223,7 @@ class NamedTypeBuilder extends TypeBuilder {
     TypeDeclarationBuilder declaration = this.declaration;
     if (declaration is ClassBuilder) {
       return declaration.buildSupertype(library, arguments);
-    } else if (declaration is InvalidTypeBuilder) {
+    } else if (declaration is InvalidTypeDeclarationBuilder) {
       library.addProblem(
           declaration.message.messageObject,
           declaration.message.charOffset,
@@ -240,7 +241,7 @@ class NamedTypeBuilder extends TypeBuilder {
     TypeDeclarationBuilder declaration = this.declaration;
     if (declaration is ClassBuilder) {
       return declaration.buildMixedInType(library, arguments);
-    } else if (declaration is InvalidTypeBuilder) {
+    } else if (declaration is InvalidTypeDeclarationBuilder) {
       library.addProblem(
           declaration.message.messageObject,
           declaration.message.charOffset,

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

@@ -6,8 +6,6 @@ library fasta.type_builder;
 
 import 'package:kernel/ast.dart' show DartType, Supertype;
 
-import '../fasta_codes.dart' show LocatedMessage;
-
 import '../scope.dart';
 import 'library_builder.dart';
 import 'nullability_builder.dart';
@@ -58,8 +56,6 @@ abstract class TypeBuilder {
   /// resolved later.
   TypeBuilder clone(List<TypeBuilder> newTypes);
 
-  buildInvalidType(LocatedMessage message, {List<LocatedMessage> context});
-
   String get fullNameForErrors => "${printOn(new StringBuffer())}";
 
   DartType build(LibraryBuilder library);

pkg/front_end/lib/src/fasta/dill/dill_library_builder.dart

@@ -43,7 +43,7 @@ import '../builder/member_builder.dart';
 import '../builder/type_alias_builder.dart';
 
 import '../kernel/kernel_builder.dart'
-    show Builder, DynamicTypeBuilder, InvalidTypeBuilder, Scope;
+    show Builder, DynamicTypeBuilder, InvalidTypeDeclarationBuilder, Scope;
 
 import '../kernel/redirecting_factory_body.dart' show RedirectingFactoryBody;
 
@@ -230,15 +230,15 @@ class DillLibraryBuilder extends LibraryBuilderImpl {
       String name, Builder builder, Builder other, int charOffset,
       {bool isExport: false, bool isImport: false}) {
     if (builder == other) return builder;
-    if (builder is InvalidTypeBuilder) return builder;
-    if (other is InvalidTypeBuilder) return other;
+    if (builder is InvalidTypeDeclarationBuilder) return builder;
+    if (other is InvalidTypeDeclarationBuilder) return other;
     // For each entry mapping key `k` to declaration `d` in `NS` an entry
     // mapping `k` to `d` is added to the exported namespace of `L` unless a
     // top-level declaration with the name `k` exists in `L`.
     if (builder.parent == this) return builder;
     Message message = templateDuplicatedDeclaration.withArguments(name);
     addProblem(message, charOffset, name.length, fileUri);
-    return new InvalidTypeBuilder(
+    return new InvalidTypeDeclarationBuilder(
         name, message.withLocation(fileUri, charOffset, name.length));
   }
 
@@ -271,7 +271,8 @@ class DillLibraryBuilder extends LibraryBuilderImpl {
               ? templateTypeNotFound.withArguments(name)
               : templateUnspecified.withArguments(messageText);
           addProblem(message, -1, noLength, null);
-          declaration = new InvalidTypeBuilder(name, message.withoutLocation());
+          declaration = new InvalidTypeDeclarationBuilder(
+              name, message.withoutLocation());
       }
       exportScopeBuilder.addMember(name, declaration);
     });

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

@@ -2816,7 +2816,7 @@ class BodyBuilder extends ScopeListener<JumpTarget>
         push(new UnresolvedType(
             new NamedTypeBuilder(name,
                 libraryBuilder.nullableBuilderIfTrue(isMarkedAsNullable), null)
-              ..bind(new InvalidTypeBuilder(
+              ..bind(new InvalidTypeDeclarationBuilder(
                   name,
                   message.withLocation(
                       uri, offset, lengthOfSpan(beginToken, suffix)))),
@@ -2838,7 +2838,7 @@ class BodyBuilder extends ScopeListener<JumpTarget>
           name.message, name.charOffset, name.name.length, name.fileUri);
       result = new NamedTypeBuilder(name.name,
           libraryBuilder.nullableBuilderIfTrue(isMarkedAsNullable), null)
-        ..bind(new InvalidTypeBuilder(
+        ..bind(new InvalidTypeDeclarationBuilder(
             name.name,
             name.message.withLocation(
                 name.fileUri, name.charOffset, name.name.length)));
@@ -3809,7 +3809,7 @@ class BodyBuilder extends ScopeListener<JumpTarget>
       } else {
         errorName ??= debugName(type.name, name);
       }
-    } else if (type is InvalidTypeBuilder) {
+    } else if (type is InvalidTypeDeclarationBuilder) {
       LocatedMessage message = type.message;
       return evaluateArgumentsBefore(
           arguments,
@@ -5195,7 +5195,8 @@ class BodyBuilder extends ScopeListener<JumpTarget>
       return new UnresolvedType(
           new NamedTypeBuilder(
               typeParameter.name, builder.nullabilityBuilder, null)
-            ..bind(new InvalidTypeBuilder(typeParameter.name, message)),
+            ..bind(
+                new InvalidTypeDeclarationBuilder(typeParameter.name, message)),
           unresolved.charOffset,
           unresolved.fileUri);
     }

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

@@ -73,7 +73,7 @@ import 'kernel_builder.dart'
     show
         AccessErrorBuilder,
         Builder,
-        InvalidTypeBuilder,
+        InvalidTypeDeclarationBuilder,
         LoadLibraryBuilder,
         NamedTypeBuilder,
         TypeBuilder,
@@ -257,7 +257,7 @@ abstract class Generator {
     Message message = templateNotAType.withArguments(token.lexeme);
     _helper.libraryBuilder
         .addProblem(message, fileOffset, lengthForToken(token), _uri);
-    result.bind(result.buildInvalidType(
+    result.bind(result.buildInvalidTypeDeclarationBuilder(
         message.withLocation(_uri, fileOffset, lengthForToken(token))));
     return result;
   }
@@ -2834,8 +2834,9 @@ class DeferredAccessGenerator extends Generator {
     TypeBuilder type = suffixGenerator.buildTypeWithResolvedArguments(
         nullabilityBuilder, arguments);
     LocatedMessage message;
-    if (type is NamedTypeBuilder && type.declaration is InvalidTypeBuilder) {
-      InvalidTypeBuilder declaration = type.declaration;
+    if (type is NamedTypeBuilder &&
+        type.declaration is InvalidTypeDeclarationBuilder) {
+      InvalidTypeDeclarationBuilder declaration = type.declaration;
       message = declaration.message;
     } else {
       int charOffset = offsetForToken(prefixGenerator.token);
@@ -2850,7 +2851,7 @@ class DeferredAccessGenerator extends Generator {
         new NamedTypeBuilder(name, nullabilityBuilder, null);
     _helper.libraryBuilder.addProblem(
         message.messageObject, message.charOffset, message.length, message.uri);
-    result.bind(result.buildInvalidType(message));
+    result.bind(result.buildInvalidTypeDeclarationBuilder(message));
     return result;
   }
 
@@ -2993,8 +2994,8 @@ class TypeUseGenerator extends ReadOnlyAccessGenerator {
   @override
   Expression get expression {
     if (super.expression == null) {
-      if (declaration is InvalidTypeBuilder) {
-        InvalidTypeBuilder declaration = this.declaration;
+      if (declaration is InvalidTypeDeclarationBuilder) {
+        InvalidTypeDeclarationBuilder declaration = this.declaration;
         super.expression = _helper.buildProblemErrorIfConst(
             declaration.message.messageObject, fileOffset, token.length);
       } else {
@@ -3930,7 +3931,7 @@ class UnexpectedQualifiedUseGenerator extends Generator {
         offsetForToken(prefixGenerator.token),
         lengthOfSpan(prefixGenerator.token, token),
         _uri);
-    result.bind(result.buildInvalidType(message.withLocation(
+    result.bind(result.buildInvalidTypeDeclarationBuilder(message.withLocation(
         _uri,
         offsetForToken(prefixGenerator.token),
         lengthOfSpan(prefixGenerator.token, token))));
@@ -4027,8 +4028,8 @@ class ParserErrorGenerator extends Generator {
     NamedTypeBuilder result =
         new NamedTypeBuilder(token.lexeme, nullabilityBuilder, null);
     _helper.libraryBuilder.addProblem(message, fileOffset, noLength, _uri);
-    result.bind(result
-        .buildInvalidType(message.withLocation(_uri, fileOffset, noLength)));
+    result.bind(result.buildInvalidTypeDeclarationBuilder(
+        message.withLocation(_uri, fileOffset, noLength)));
     return result;
   }