| // 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 'dart:collection' show HashSet; |
| |
| import 'package:analyzer/dart/ast/ast.dart' show Identifier; |
| import 'package:analyzer/dart/element/element.dart'; |
| import 'package:analyzer/src/dart/element/element.dart' show FieldElementImpl; |
| |
| import '../js_ast/js_ast.dart' as JS; |
| import 'element_helpers.dart'; |
| import 'js_names.dart' as JS; |
| |
| /// Tracks how fields, getters and setters are represented when emitting JS. |
| /// |
| /// Dart classes have implicit features that must be made explicit: |
| /// |
| /// - virtual fields induce a getter and setter pair. |
| /// - getters and setters are independent. |
| /// - getters and setters can be overridden. |
| /// |
| class ClassPropertyModel { |
| /// Fields that are virtual, that is, they must be generated as a property |
| /// pair in JavaScript. |
| /// |
| /// The value property stores the symbol used for the field's storage slot. |
| final virtualFields = <FieldElement, JS.TemporaryId>{}; |
| |
| /// Static fields that are overridden, this does not matter for Dart but in |
| /// JS we need to take care initializing these because JS classes inherit |
| /// statics. |
| final staticFieldOverrides = new HashSet<FieldElement>(); |
| |
| /// The set of inherited getters, used because JS getters/setters are paired, |
| /// so if we're generating a setter we may need to emit a getter that calls |
| /// super. |
| final inheritedGetters = new HashSet<String>(); |
| |
| /// The set of inherited setters, used because JS getters/setters are paired, |
| /// so if we're generating a getter we may need to emit a setter that calls |
| /// super. |
| final inheritedSetters = new HashSet<String>(); |
| |
| ClassPropertyModel.build( |
| ClassElement classElem, Iterable<ExecutableElement> extensionMembers) { |
| // Visit superclasses to collect information about their fields/accessors. |
| // This is expensive so we try to collect everything in one pass. |
| for (var base in getSuperclasses(classElem)) { |
| for (var accessor in base.accessors) { |
| // For getter/setter pairs only process them once. |
| if (accessor.correspondingGetter != null) continue; |
| |
| var field = accessor.variable; |
| var name = field.name; |
| // Ignore private names from other libraries. |
| if (Identifier.isPrivateName(name) && |
| accessor.library != classElem.library) { |
| continue; |
| } |
| |
| if (field.getter?.isAbstract == false) inheritedGetters.add(name); |
| if (field.setter?.isAbstract == false) inheritedSetters.add(name); |
| } |
| } |
| |
| var extensionNames = |
| new HashSet<String>.from(extensionMembers.map((e) => e.name)); |
| |
| // Visit accessors in the current class, and see if they need to be |
| // generated differently based on the inherited fields/accessors. |
| for (var accessor in classElem.accessors) { |
| // For getter/setter pairs only process them once. |
| if (accessor.correspondingGetter != null) continue; |
| // Also ignore abstract fields. |
| if (accessor.isAbstract) continue; |
| |
| var field = accessor.variable; |
| var name = field.name; |
| // Is it a field? |
| if (!field.isSynthetic && field is FieldElementImpl) { |
| if (inheritedGetters.contains(name) || |
| inheritedSetters.contains(name) || |
| extensionNames.contains(name) || |
| field.isVirtual) { |
| if (field.isStatic) { |
| staticFieldOverrides.add(field); |
| } else { |
| virtualFields[field] = new JS.TemporaryId(name); |
| } |
| } |
| } |
| } |
| } |
| } |