pkg/front_end/lib/src/source/source_extension_builder.dart

// 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:kernel/ast.dart';
import 'package:kernel/class_hierarchy.dart';

import '../base/modifiers.dart';
import '../base/name_space.dart';
import '../base/problems.dart';
import '../base/scope.dart';
import '../builder/declaration_builders.dart';
import '../builder/library_builder.dart';
import '../builder/member_builder.dart';
import '../builder/metadata_builder.dart';
import '../builder/type_builder.dart';
import '../fragment/fragment.dart';
import '../kernel/body_builder_context.dart';
import '../kernel/kernel_helper.dart';
import 'name_scheme.dart';
import 'source_builder_mixins.dart';
import 'source_library_builder.dart';
import 'source_member_builder.dart';
import 'source_type_parameter_builder.dart';
import 'type_parameter_scope_builder.dart';

class SourceExtensionBuilder extends ExtensionBuilderImpl
    with SourceDeclarationBuilderMixin {
  @override
  final SourceLibraryBuilder libraryBuilder;

  final int _nameOffset;

  @override
  final Uri fileUri;

  final Modifiers _modifiers;

  late final Extension _extension;

  final DeclarationNameSpaceBuilder _nameSpaceBuilder;

  late final DeclarationNameSpace _nameSpace;
  late final List<SourceMemberBuilder> _constructorBuilders;
  late final List<SourceMemberBuilder> _memberBuilders;

  @override
  final List<SourceNominalParameterBuilder>? typeParameters;

  @override
  final TypeBuilder onType;

  final ExtensionName extensionName;

  final Reference _reference;

  /// The `extension` declaration that introduces this extension. Subsequent
  /// extensions of the same name must be augmentations.
  final ExtensionFragment _introductory;

  final List<ExtensionFragment> _augmentations;

  SourceExtensionBuilder(
      {required SourceLibraryBuilder enclosingLibraryBuilder,
      required this.fileUri,
      required int startOffset,
      required int nameOffset,
      required int endOffset,
      required DeclarationNameSpaceBuilder nameSpaceBuilder,
      required ExtensionFragment introductory,
      required List<ExtensionFragment> augmentations,
      required Reference? reference})
      : _introductory = introductory,
        _augmentations = augmentations,
        _reference = reference ?? new Reference(),
        _nameOffset = nameOffset,
        libraryBuilder = enclosingLibraryBuilder,
        _modifiers = introductory.modifiers,
        extensionName = introductory.extensionName,
        typeParameters = introductory.typeParameters?.builders,
        onType = introductory.onType,
        _nameSpaceBuilder = nameSpaceBuilder {
    _introductory.builder = this;
    _introductory.bodyScope.declarationBuilder = this;
    for (ExtensionFragment augmentation in _augmentations) {
      augmentation.builder = this;
      augmentation.bodyScope.declarationBuilder = this;
    }

    // TODO(johnniwinther): Move this to the [build] once augmentations are
    // handled through fragments.
    _extension = new Extension(
        name: extensionName.name,
        fileUri: fileUri,
        typeParameters:
            SourceNominalParameterBuilder.typeParametersFromBuilders(
                typeParameters),
        reference: _reference)
      ..isUnnamedExtension = extensionName.isUnnamedExtension
      ..fileOffset = _nameOffset;
    extensionName.attachExtension(_extension);
  }

  @override
  Iterator<SourceMemberBuilder> get unfilteredMembersIterator =>
      _memberBuilders.iterator;

  @override
  Iterator<T> filteredMembersIterator<T extends MemberBuilder>(
          {required bool includeDuplicates}) =>
      new FilteredIterator<T>(_memberBuilders.iterator,
          includeDuplicates: includeDuplicates);

  @override
  Iterator<SourceMemberBuilder> get unfilteredConstructorsIterator =>
      _constructorBuilders.iterator;

  @override
  Iterator<T> filteredConstructorsIterator<T extends MemberBuilder>(
          {required bool includeDuplicates}) =>
      new FilteredIterator<T>(_constructorBuilders.iterator,
          includeDuplicates: includeDuplicates);

  @override
  int get fileOffset => _nameOffset;

  @override
  String get name => extensionName.name;

  @override
  DeclarationNameSpace get nameSpace => _nameSpace;

  @override
  // Coverage-ignore(suite): Not run.
  bool get isStatic => _modifiers.isStatic;

  @override
  void buildScopes(LibraryBuilder coreLibrary) {
    _constructorBuilders = [];
    _memberBuilders = [];
    _nameSpace = _nameSpaceBuilder.buildNameSpace(
        loader: libraryBuilder.loader,
        problemReporting: libraryBuilder,
        enclosingLibraryBuilder: libraryBuilder,
        declarationBuilder: this,
        indexedLibrary: libraryBuilder.indexedLibrary,
        // Extensions do not have a corresponding [IndexedContainer] since their
        // members are stored in the enclosing library.
        indexedContainer: null,
        containerType: ContainerType.Extension,
        containerName: extensionName,
        includeConstructors: false,
        constructorBuilders: _constructorBuilders,
        memberBuilders: _memberBuilders);
  }

  @override
  SourceLibraryBuilder get parent => libraryBuilder;

  bool get isUnnamedExtension => extensionName.isUnnamedExtension;

  @override
  Reference get reference => _reference;

  @override
  Extension get extension => _extension;

  BodyBuilderContext _createBodyBuilderContext() {
    return new ExtensionBodyBuilderContext(this);
  }

  /// Builds the [Extension] for this extension build and inserts the members
  /// into the [Library] of [libraryBuilder].
  ///
  /// [addMembersToLibrary] is `true` if the extension members should be added
  /// to the library. This is `false` if the extension is in conflict with
  /// another library member. In this case, the extension member should not be
  /// added to the library to avoid name clashes with other members in the
  /// library.
  Extension build(LibraryBuilder coreLibrary,
      {required bool addMembersToLibrary}) {
    _extension.onType = onType.build(libraryBuilder, TypeUse.extensionOnType);

    buildInternal(coreLibrary, addMembersToLibrary: addMembersToLibrary);
    return _extension;
  }

  void _buildOutlineExpressionsForFragment(ExtensionFragment fragment,
      ClassHierarchy classHierarchy, BodyBuilderContext bodyBuilderContext) {
    MetadataBuilder.buildAnnotations(
        annotatable: extension,
        annotatableFileUri: extension.fileUri,
        metadata: fragment.metadata,
        bodyBuilderContext: bodyBuilderContext,
        libraryBuilder: libraryBuilder,
        scope: fragment.enclosingScope);
  }

  void buildOutlineExpressions(ClassHierarchy classHierarchy,
      List<DelayedDefaultValueCloner> delayedDefaultValueCloners) {
    BodyBuilderContext bodyBuilderContext = _createBodyBuilderContext();
    _buildOutlineExpressionsForFragment(
        _introductory, classHierarchy, bodyBuilderContext);
    for (ExtensionFragment augmentation in _augmentations) {
      _buildOutlineExpressionsForFragment(
          augmentation, classHierarchy, bodyBuilderContext);
    }

    if (typeParameters != null) {
      for (int i = 0; i < typeParameters!.length; i++) {
        typeParameters![i].buildOutlineExpressions(
            libraryBuilder, bodyBuilderContext, classHierarchy);
      }
    }

    Iterator<SourceMemberBuilder> iterator =
        filteredMembersIterator(includeDuplicates: false);
    while (iterator.moveNext()) {
      iterator.current
          .buildOutlineExpressions(classHierarchy, delayedDefaultValueCloners);
    }
  }

  @override
  // Coverage-ignore(suite): Not run.
  void addMemberInternal(SourceMemberBuilder memberBuilder,
      BuiltMemberKind memberKind, Member member, Member? tearOff) {
    unhandled("${memberBuilder.runtimeType}:${memberKind}", "addMemberInternal",
        memberBuilder.fileOffset, memberBuilder.fileUri);
  }

  @override
  void addMemberDescriptorInternal(
      SourceMemberBuilder memberBuilder,
      BuiltMemberKind memberKind,
      Reference memberReference,
      Reference? tearOffReference) {
    String name = memberBuilder.name;
    ExtensionMemberKind kind;
    bool isInternalImplementation = false;
    switch (memberKind) {
      case BuiltMemberKind.Constructor:
      case BuiltMemberKind.RedirectingFactory:
      case BuiltMemberKind.Factory:
      case BuiltMemberKind.Field:
      case BuiltMemberKind.Method:
      case BuiltMemberKind.ExtensionTypeConstructor:
      case BuiltMemberKind.ExtensionTypeMethod:
      case BuiltMemberKind.ExtensionTypeGetter:
      case BuiltMemberKind.ExtensionTypeSetter:
      case BuiltMemberKind.ExtensionTypeOperator:
      case BuiltMemberKind.ExtensionTypeFactory:
      case BuiltMemberKind.ExtensionTypeRedirectingFactory:
      case BuiltMemberKind.ExtensionTypeRepresentationField:
        // Coverage-ignore(suite): Not run.
        unhandled(
            "$memberBuilder(${memberBuilder.runtimeType}):${memberKind}",
            "addMemberDescriptorInternal",
            memberBuilder.fileOffset,
            memberBuilder.fileUri);
      case BuiltMemberKind.ExtensionField:
        kind = ExtensionMemberKind.Field;
        break;
      case BuiltMemberKind.LateBackingField:
      case BuiltMemberKind.LateIsSetField:
        isInternalImplementation = true;
        kind = ExtensionMemberKind.Field;
        break;
      case BuiltMemberKind.ExtensionMethod:
        kind = ExtensionMemberKind.Method;
        break;
      case BuiltMemberKind.ExtensionGetter:
      case BuiltMemberKind.LateGetter:
        kind = ExtensionMemberKind.Getter;
        break;
      case BuiltMemberKind.ExtensionSetter:
      case BuiltMemberKind.LateSetter:
        kind = ExtensionMemberKind.Setter;
        break;
      case BuiltMemberKind.ExtensionOperator:
        kind = ExtensionMemberKind.Operator;
        break;
    }
    extension.memberDescriptors.add(new ExtensionMemberDescriptor(
        name: new Name(name, libraryBuilder.library),
        memberReference: memberReference,
        tearOffReference: tearOffReference,
        isStatic: memberBuilder.isStatic,
        isInternalImplementation: isInternalImplementation,
        kind: kind));
  }
}