pkg/analyzer/lib/src/dart/element/scope.dart - sdk - Git at Google

 // Copyright (c) 2020, 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:_fe_analyzer_shared/src/scanner/string_canonicalizer.dart';
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/scope.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/extensions.dart';
 import 'package:analyzer/src/summary2/combinator.dart';
 import 'package:analyzer/src/utilities/extensions/collection.dart';

 /// The scope for the initializers in a constructor.
 class ConstructorInitializerScope extends EnclosedScope {
   ConstructorInitializerScope(super.parent, ConstructorElement element) {
     for (var parameter in element.parameters) {
       // Skip wildcards.
       if (parameter.name == '_' &&
           element.library.featureSet.isEnabled(Feature.wildcard_variables)) {
         continue;
       }
       _addGetter(parameter);
     }
   }
 }

 /// The scope that looks up elements in doc imports.
 ///
 /// Attempts to look up elements in its [innerScope] before searching
 /// through the doc imports.
 class DocImportScope with _GettersAndSetters implements Scope {
   /// The scope that will be prioritized in look ups before searching in doc
   /// imports.
   ///
   /// Will be set for each specific comment scope in the `ScopeResolverVisitor`.
   Scope innerScope;

   DocImportScope(this.innerScope, List<LibraryElement> docImportLibraries) {
     for (var importedLibrary in docImportLibraries) {
       if (importedLibrary is LibraryElementImpl) {
         // TODO(kallentu): Handle combinators.
         for (var exportedReference in importedLibrary.exportedReferences) {
           var reference = exportedReference.reference;
           var element = importedLibrary.session.elementFactory
               .elementOfReference(reference)!;
           if (element is PropertyAccessorElement && element.isSetter) {
             _addSetter(element);
           } else {
             _addGetter(element);
           }
         }
       }
     }
   }

   @override
   ScopeLookupResult lookup(String id) {
     var result = innerScope.lookup(id);
     if (result.getter != null || result.setter != null) return result;
     return ScopeLookupResultImpl(_getters[id], _setters[id]);
   }
 }

 /// A scope that is lexically enclosed in another scope.
 class EnclosedScope with _GettersAndSetters implements Scope {
   final Scope _parent;

   EnclosedScope(Scope parent) : _parent = parent;

   Scope get parent => _parent;

   @override
   ScopeLookupResult lookup(String id) {
     var getter = _getters[id];
     var setter = _setters[id];
     if (getter != null || setter != null) {
       return ScopeLookupResultImpl(getter, setter);
     }

     return _parent.lookup(id);
   }
 }

 /// The scope defined by an extension.
 class ExtensionScope extends EnclosedScope {
   ExtensionScope(
     super.parent,
     ExtensionElement element,
   ) {
     element.accessors.forEach(_addPropertyAccessor);
     element.methods.forEach(_addGetter);
   }
 }

 class FormalParameterScope extends EnclosedScope {
   FormalParameterScope(
     super.parent,
     List<ParameterElement> elements,
   ) {
     for (var parameter in elements) {
       if (parameter is! FieldFormalParameterElement &&
           parameter is! SuperFormalParameterElement) {
         if (!parameter.isWildcardVariable) {
           _addGetter(parameter);
         }
       }
     }
   }
 }

 /// The scope defined by an instance element.
 class InstanceScope extends EnclosedScope {
   InstanceScope(super.parent, InstanceElement element) {
     var augmented = element.augmented;
     augmented.accessors.forEach(_addPropertyAccessor);
     augmented.methods.forEach(_addGetter);
   }
 }

 /// The top-level declarations of the library.
 class LibraryDeclarations with _GettersAndSetters {
   List<ExtensionElement> extensions = [];

   LibraryDeclarations(LibraryElementImpl library) {
     library.units.forEach(_addLibraryFragment);

     // Add implicit 'dart:core' declarations.
     if ('${library.source.uri}' == 'dart:core') {
       _addGetter(DynamicElementImpl.instance);
       _addGetter(NeverElementImpl.instance);
     }

     extensions = extensions.toFixedList();
   }

   void _addExtension(ExtensionElement element) {
     if (element.isAugmentation) {
       return;
     }

     _addGetter(element);
     if (!extensions.contains(element)) {
       extensions.add(element);
     }
   }

   void _addLibraryFragment(CompilationUnitElement fragment) {
     for (var element in fragment.accessors) {
       if (element.augmentation == null) {
         _addPropertyAccessor(element);
       }
     }

     for (var element in fragment.functions) {
       if (element.augmentation == null) {
         _addGetter(element);
       }
     }

     fragment.enums.forEach(_addGetter);
     fragment.extensions.forEach(_addExtension);
     fragment.extensionTypes.forEach(_addGetter);
     fragment.typeAliases.forEach(_addGetter);
     fragment.mixins.forEach(_addGetter);
     fragment.classes.forEach(_addGetter);
   }
 }

 class LibraryFragmentScope implements Scope {
   final LibraryFragmentScope? parent;
   final CompilationUnitElementImpl fragment;
   final PrefixScope noPrefixScope;

   final Map<String, PrefixElementImpl> _prefixElements = {};
   final Map<PrefixElementImpl, PrefixScope> _prefixScopes = {};

   /// The cached result for [accessibleExtensions].
   List<ExtensionElement>? _extensions;

   factory LibraryFragmentScope(CompilationUnitElementImpl fragment) {
     return LibraryFragmentScope._(
       parent: fragment.enclosingElement3?.scope,
       fragment: fragment,
       noPrefixScope: PrefixScope(
         libraryElement: fragment.library,
         parent: null,
         libraryImports: fragment.libraryImports,
         prefix: null,
       ),
     );
   }

   LibraryFragmentScope._({
     required this.parent,
     required this.fragment,
     required this.noPrefixScope,
   }) {
     for (var prefix in fragment.libraryImportPrefixes) {
       _prefixElements[prefix.name] = prefix;
       _prefixScopes[prefix] = PrefixScope(
         libraryElement: fragment.library,
         parent: _getParentPrefixScope(prefix),
         libraryImports: fragment.libraryImports,
         prefix: prefix,
       );
     }
   }

   /// The extensions accessible within [fragment].
   List<ExtensionElement> get accessibleExtensions {
     var libraryDeclarations = fragment.library.libraryDeclarations;
     return _extensions ??= {
       ...libraryDeclarations.extensions,
       ...noPrefixScope._extensions,
       for (var prefixScope in _prefixScopes.values) ...prefixScope._extensions,
       ...?parent?.accessibleExtensions,
     }.toFixedList();
   }

   PrefixScope getPrefixScope(PrefixElementImpl prefix) {
     // SAFETY: We create the scope for each prefix.
     return _prefixScopes[prefix]!;
   }

   @override
   ScopeLookupResult lookup(String id) {
     // Try declarations of the whole library.
     if (_lookupLibrary(id) case var result?) {
       return result;
     }

     // Try the combined import scope.
     var importResult = _lookupCombined(id);
     if (importResult != null) {
       return importResult;
     }

     // No parent, no result.
     return ScopeLookupResultImpl(null, null);
   }

   PrefixScope? _getParentPrefixScope(PrefixElementImpl prefix) {
     var isDeferred = prefix.imports.any((import) {
       return import.prefix is DeferredImportElementPrefix;
     });
     if (isDeferred) {
       return null;
     }

     for (var scope = parent; scope != null; scope = scope.parent) {
       var parentPrefix = scope._prefixElements[prefix.name];
       if (parentPrefix != null) {
         return scope._prefixScopes[parentPrefix];
       }
     }
     return null;
   }

   ScopeLookupResult? _lookupCombined(String id) {
     // Try prefix elements.
     if (_shouldTryPrefixElement(id)) {
       if (_prefixElements[id] case var prefixElement?) {
         return ScopeLookupResultImpl(prefixElement, null);
       }
     }

     // Try imports of the library fragment.
     var noPrefixResult = noPrefixScope.lookup(id);
     if (noPrefixResult.getter != null || noPrefixResult.setter != null) {
       return noPrefixResult;
     }

     // Try the parent's combined import scope.
     var parentResult = parent?._lookupCombined(id);
     if (parentResult != null) {
       return parentResult;
     }

     return null;
   }

   ScopeLookupResult? _lookupLibrary(String id) {
     var libraryDeclarations = fragment.library.libraryDeclarations;
     var libraryGetter = libraryDeclarations._getters[id];
     var librarySetter = libraryDeclarations._setters[id];
     if (libraryGetter != null || librarySetter != null) {
       return ScopeLookupResultImpl(
         libraryGetter,
         librarySetter,
       );
     }
     return null;
   }

   bool _shouldTryPrefixElement(String id) {
     if (id == '_') {
       var featureSet = fragment.library.featureSet;
       return !featureSet.isEnabled(Feature.wildcard_variables);
     }
     return true;
   }
 }

 class LocalScope extends EnclosedScope {
   LocalScope(super.parent);

   void add(Element element) {
     if (!element.isWildcardVariable) {
       _addGetter(element);
     }
   }
 }

 class PrefixScope implements Scope {
   final LibraryElementImpl libraryElement;
   final PrefixScope? parent;

   final Map<String, Element> _getters = {};
   final Map<String, Element> _setters = {};
   Set<String>? _settersFromDeprecatedExport;
   Set<String>? _gettersFromDeprecatedExport;
   final Set<ExtensionElement> _extensions = {};
   LibraryElement? _deferredLibrary;

   PrefixScope({
     required this.libraryElement,
     required this.parent,
     required List<LibraryImportElement> libraryImports,
     required PrefixElement? prefix,
   }) {
     var elementFactory = libraryElement.session.elementFactory;
     for (var import in libraryImports) {
       var importedUri = import.uri;
       if (importedUri is DirectiveUriWithLibrary &&
           import.prefix?.element == prefix) {
         var importedLibrary = importedUri.library;
         if (importedLibrary is LibraryElementImpl) {
           var combinators = import.combinators.build();
           for (var exportedReference in importedLibrary.exportedReferences) {
             var reference = exportedReference.reference;
             if (combinators.allows(reference.name)) {
               var element = elementFactory.elementOfReference(reference)!;
               if (_shouldAdd(importedLibrary, element)) {
                 _add(
                   element,
                   importedLibrary.isFromDeprecatedExport(exportedReference),
                 );
               }
             }
           }
           if (import.prefix is DeferredImportElementPrefix) {
             _deferredLibrary ??= importedLibrary;
           }
         }
       }
     }
   }

   @override
   ScopeLookupResult lookup(String id) {
     var deferredLibrary = _deferredLibrary;
     if (deferredLibrary != null && id == FunctionElement.LOAD_LIBRARY_NAME) {
       return ScopeLookupResultImpl(deferredLibrary.loadLibraryFunction, null);
     }

     var getter = _getters[id];
     var setter = _setters[id];
     if (getter != null || setter != null) {
       return PrefixScopeLookupResult(
         getter,
         setter,
         _gettersFromDeprecatedExport?.contains(id) ?? false,
         _settersFromDeprecatedExport?.contains(id) ?? false,
       );
     }

     if (parent case var parent?) {
       return parent.lookup(id);
     }

     return ScopeLookupResultImpl(null, null);
   }

   void _add(Element element, bool isFromDeprecatedExport) {
     if (element is PropertyAccessorElement && element.isSetter) {
       _addTo(
         element,
         isFromDeprecatedExport: isFromDeprecatedExport,
         isSetter: true,
       );
     } else {
       _addTo(
         element,
         isFromDeprecatedExport: isFromDeprecatedExport,
         isSetter: false,
       );
       if (element is ExtensionElement) {
         _extensions.add(element);
       }
     }
   }

   void _addTo(
     Element element, {
     required bool isFromDeprecatedExport,
     required bool isSetter,
   }) {
     var map = isSetter ? _setters : _getters;
     var id = element.displayName;
     var existing = map[id];

     if (existing == null) {
       map[id] = element;
       if (isFromDeprecatedExport) {
         if (isSetter) {
           (_settersFromDeprecatedExport ??= {}).add(id);
         } else {
           (_gettersFromDeprecatedExport ??= {}).add(id);
         }
       }
       return;
     }

     var deprecatedSet =
         isSetter ? _settersFromDeprecatedExport : _gettersFromDeprecatedExport;
     var wasFromDeprecatedExport = deprecatedSet?.contains(id) ?? false;
     if (existing == element) {
       if (wasFromDeprecatedExport && !isFromDeprecatedExport) {
         deprecatedSet!.remove(id);
       }
       return;
     }

     map[id] = _merge(existing, element);
     if (wasFromDeprecatedExport) {
       deprecatedSet!.remove(id);
     }
   }

   Element _merge(Element existing, Element other) {
     if (_isSdkElement(existing)) {
       if (!_isSdkElement(other)) {
         return other;
       }
     } else {
       if (_isSdkElement(other)) {
         return existing;
       }
     }

     var conflictingElements = <Element>{};
     _addElement(conflictingElements, existing);
     _addElement(conflictingElements, other);

     return MultiplyDefinedElementImpl(
       libraryElement.context,
       libraryElement.session,
       conflictingElements.first.name!,
       conflictingElements.toList(),
     );
   }

   bool _shouldAdd(LibraryElementImpl importedLibrary, Element element) {
     // It is an error for the identifier `Record`, denoting the `Record` class
     // from `dart:core`, where that import scope name is only imported from
     // platform libraries, to appear in a library whose language version is
     // less than `v`; assuming that `v` is the language version in which
     // records are released.
     if (!libraryElement.featureSet.isEnabled(Feature.records)) {
       if (importedLibrary.isInSdk &&
           element is ClassElementImpl &&
           element.isDartCoreRecord) {
         return false;
       }
     }
     return true;
   }

   static void _addElement(
     Set<Element> conflictingElements,
     Element element,
   ) {
     if (element is MultiplyDefinedElementImpl) {
       conflictingElements.addAll(element.conflictingElements);
     } else {
       conflictingElements.add(element);
     }
   }

   static bool _isSdkElement(Element element) {
     if (element is DynamicElementImpl || element is NeverElementImpl) {
       return true;
     }
     if (element is MultiplyDefinedElement) {
       return false;
     }
     return element.library!.isInSdk;
   }
 }

 class PrefixScopeLookupResult extends ScopeLookupResultImpl {
   static const int getterIsFromDeprecatedExportBit = 1 << 0;
   static const int setterIsFromDeprecatedExportBit = 1 << 1;

   final int _deprecatedBits;

   PrefixScopeLookupResult(
     super.importedGetter,
     super.importedSetter,
     bool getterIsFromDeprecatedExport,
     bool setterIsFromDeprecatedExport,
   ) : _deprecatedBits = (getterIsFromDeprecatedExport
                 ? getterIsFromDeprecatedExportBit
                 : 0) |
             (setterIsFromDeprecatedExport
                 ? setterIsFromDeprecatedExportBit
                 : 0);

   /// This flag is set to `true` if [getter] is available using import
   /// directives where every imported library re-exports the element, and
   /// every such `export` directive is marked as deprecated.
   bool get getterIsFromDeprecatedExport =>
       (_deprecatedBits & getterIsFromDeprecatedExportBit) != 0;

   /// This flag is set to `true` if [setter] is available using import
   /// directives where every imported library re-exports the element, and
   /// every such `export` directive is marked as deprecated.
   bool get setterIsFromDeprecatedExport =>
       (_deprecatedBits & setterIsFromDeprecatedExportBit) != 0;
 }

 class ScopeLookupResultImpl implements ScopeLookupResult {
   @override
   final Element? getter;

   @override
   final Element? setter;

   ScopeLookupResultImpl(this.getter, this.setter);
 }

 class TypeParameterScope extends EnclosedScope {
   TypeParameterScope(
     super.parent,
     List<TypeParameterElement> elements,
   ) {
     for (var element in elements) {
       if (!element.isWildcardVariable) {
         _addGetter(element);
       }
     }
   }
 }

 mixin _GettersAndSetters {
   final Map<String, Element> _getters = {};
   final Map<String, Element> _setters = {};

   void _addGetter(Element element) {
     var id = element.name;
     if (id != null) {
       _getters[id] ??= element;
     }
   }

   void _addPropertyAccessor(PropertyAccessorElement element) {
     if (element.isGetter) {
       _addGetter(element);
     } else {
       _addSetter(element);
     }
   }

   void _addSetter(Element element) {
     var name = element.name;
     if (name != null && name.endsWith('=')) {
       var id = considerCanonicalizeString(name.substring(0, name.length - 1));
       _setters[id] ??= element;
     }
   }
 }
	// Copyright (c) 2020, 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:_fe_analyzer_shared/src/scanner/string_canonicalizer.dart';
	import 'package:analyzer/dart/analysis/features.dart';
	import 'package:analyzer/dart/element/element.dart';
	import 'package:analyzer/dart/element/scope.dart';
	import 'package:analyzer/src/dart/element/element.dart';
	import 'package:analyzer/src/dart/element/extensions.dart';
	import 'package:analyzer/src/summary2/combinator.dart';
	import 'package:analyzer/src/utilities/extensions/collection.dart';

	/// The scope for the initializers in a constructor.
	class ConstructorInitializerScope extends EnclosedScope {
	ConstructorInitializerScope(super.parent, ConstructorElement element) {
	for (var parameter in element.parameters) {
	// Skip wildcards.
	if (parameter.name == '_' &&
	element.library.featureSet.isEnabled(Feature.wildcard_variables)) {
	continue;
	}
	_addGetter(parameter);
	}
	}
	}

	/// The scope that looks up elements in doc imports.
	///
	/// Attempts to look up elements in its [innerScope] before searching
	/// through the doc imports.
	class DocImportScope with _GettersAndSetters implements Scope {
	/// The scope that will be prioritized in look ups before searching in doc
	/// imports.
	///
	/// Will be set for each specific comment scope in the `ScopeResolverVisitor`.
	Scope innerScope;

	DocImportScope(this.innerScope, List<LibraryElement> docImportLibraries) {
	for (var importedLibrary in docImportLibraries) {
	if (importedLibrary is LibraryElementImpl) {
	// TODO(kallentu): Handle combinators.
	for (var exportedReference in importedLibrary.exportedReferences) {
	var reference = exportedReference.reference;
	var element = importedLibrary.session.elementFactory
	.elementOfReference(reference)!;
	if (element is PropertyAccessorElement && element.isSetter) {
	_addSetter(element);
	} else {
	_addGetter(element);
	}
	}
	}
	}
	}

	@override
	ScopeLookupResult lookup(String id) {
	var result = innerScope.lookup(id);
	if (result.getter != null \|\| result.setter != null) return result;
	return ScopeLookupResultImpl(_getters[id], _setters[id]);
	}
	}

	/// A scope that is lexically enclosed in another scope.
	class EnclosedScope with _GettersAndSetters implements Scope {
	final Scope _parent;

	EnclosedScope(Scope parent) : _parent = parent;

	Scope get parent => _parent;

	@override
	ScopeLookupResult lookup(String id) {
	var getter = _getters[id];
	var setter = _setters[id];
	if (getter != null \|\| setter != null) {
	return ScopeLookupResultImpl(getter, setter);
	}

	return _parent.lookup(id);
	}
	}

	/// The scope defined by an extension.
	class ExtensionScope extends EnclosedScope {
	ExtensionScope(
	super.parent,
	ExtensionElement element,
	) {
	element.accessors.forEach(_addPropertyAccessor);
	element.methods.forEach(_addGetter);
	}
	}

	class FormalParameterScope extends EnclosedScope {
	FormalParameterScope(
	super.parent,
	List<ParameterElement> elements,
	) {
	for (var parameter in elements) {
	if (parameter is! FieldFormalParameterElement &&
	parameter is! SuperFormalParameterElement) {
	if (!parameter.isWildcardVariable) {
	_addGetter(parameter);
	}
	}
	}
	}
	}

	/// The scope defined by an instance element.
	class InstanceScope extends EnclosedScope {
	InstanceScope(super.parent, InstanceElement element) {
	var augmented = element.augmented;
	augmented.accessors.forEach(_addPropertyAccessor);
	augmented.methods.forEach(_addGetter);
	}
	}

	/// The top-level declarations of the library.
	class LibraryDeclarations with _GettersAndSetters {
	List<ExtensionElement> extensions = [];

	LibraryDeclarations(LibraryElementImpl library) {
	library.units.forEach(_addLibraryFragment);

	// Add implicit 'dart:core' declarations.
	if ('${library.source.uri}' == 'dart:core') {
	_addGetter(DynamicElementImpl.instance);
	_addGetter(NeverElementImpl.instance);
	}

	extensions = extensions.toFixedList();
	}

	void _addExtension(ExtensionElement element) {
	if (element.isAugmentation) {
	return;
	}

	_addGetter(element);
	if (!extensions.contains(element)) {
	extensions.add(element);
	}
	}

	void _addLibraryFragment(CompilationUnitElement fragment) {
	for (var element in fragment.accessors) {
	if (element.augmentation == null) {
	_addPropertyAccessor(element);
	}
	}

	for (var element in fragment.functions) {
	if (element.augmentation == null) {
	_addGetter(element);
	}
	}

	fragment.enums.forEach(_addGetter);
	fragment.extensions.forEach(_addExtension);
	fragment.extensionTypes.forEach(_addGetter);
	fragment.typeAliases.forEach(_addGetter);
	fragment.mixins.forEach(_addGetter);
	fragment.classes.forEach(_addGetter);
	}
	}

	class LibraryFragmentScope implements Scope {
	final LibraryFragmentScope? parent;
	final CompilationUnitElementImpl fragment;
	final PrefixScope noPrefixScope;

	final Map<String, PrefixElementImpl> _prefixElements = {};
	final Map<PrefixElementImpl, PrefixScope> _prefixScopes = {};

	/// The cached result for [accessibleExtensions].
	List<ExtensionElement>? _extensions;

	factory LibraryFragmentScope(CompilationUnitElementImpl fragment) {
	return LibraryFragmentScope._(
	parent: fragment.enclosingElement3?.scope,
	fragment: fragment,
	noPrefixScope: PrefixScope(
	libraryElement: fragment.library,
	parent: null,
	libraryImports: fragment.libraryImports,
	prefix: null,
	),
	);
	}

	LibraryFragmentScope._({
	required this.parent,
	required this.fragment,
	required this.noPrefixScope,
	}) {
	for (var prefix in fragment.libraryImportPrefixes) {
	_prefixElements[prefix.name] = prefix;
	_prefixScopes[prefix] = PrefixScope(
	libraryElement: fragment.library,
	parent: _getParentPrefixScope(prefix),
	libraryImports: fragment.libraryImports,
	prefix: prefix,
	);
	}
	}

	/// The extensions accessible within [fragment].
	List<ExtensionElement> get accessibleExtensions {
	var libraryDeclarations = fragment.library.libraryDeclarations;
	return _extensions ??= {
	...libraryDeclarations.extensions,
	...noPrefixScope._extensions,
	for (var prefixScope in _prefixScopes.values) ...prefixScope._extensions,
	...?parent?.accessibleExtensions,
	}.toFixedList();
	}

	PrefixScope getPrefixScope(PrefixElementImpl prefix) {
	// SAFETY: We create the scope for each prefix.
	return _prefixScopes[prefix]!;
	}

	@override
	ScopeLookupResult lookup(String id) {
	// Try declarations of the whole library.
	if (_lookupLibrary(id) case var result?) {
	return result;
	}

	// Try the combined import scope.
	var importResult = _lookupCombined(id);
	if (importResult != null) {
	return importResult;
	}

	// No parent, no result.
	return ScopeLookupResultImpl(null, null);
	}

	PrefixScope? _getParentPrefixScope(PrefixElementImpl prefix) {
	var isDeferred = prefix.imports.any((import) {
	return import.prefix is DeferredImportElementPrefix;
	});
	if (isDeferred) {
	return null;
	}

	for (var scope = parent; scope != null; scope = scope.parent) {
	var parentPrefix = scope._prefixElements[prefix.name];
	if (parentPrefix != null) {
	return scope._prefixScopes[parentPrefix];
	}
	}
	return null;
	}

	ScopeLookupResult? _lookupCombined(String id) {
	// Try prefix elements.
	if (_shouldTryPrefixElement(id)) {
	if (_prefixElements[id] case var prefixElement?) {
	return ScopeLookupResultImpl(prefixElement, null);
	}
	}

	// Try imports of the library fragment.
	var noPrefixResult = noPrefixScope.lookup(id);
	if (noPrefixResult.getter != null \|\| noPrefixResult.setter != null) {
	return noPrefixResult;
	}

	// Try the parent's combined import scope.
	var parentResult = parent?._lookupCombined(id);
	if (parentResult != null) {
	return parentResult;
	}

	return null;
	}

	ScopeLookupResult? _lookupLibrary(String id) {
	var libraryDeclarations = fragment.library.libraryDeclarations;
	var libraryGetter = libraryDeclarations._getters[id];
	var librarySetter = libraryDeclarations._setters[id];
	if (libraryGetter != null \|\| librarySetter != null) {
	return ScopeLookupResultImpl(
	libraryGetter,
	librarySetter,
	);
	}
	return null;
	}

	bool _shouldTryPrefixElement(String id) {
	if (id == '_') {
	var featureSet = fragment.library.featureSet;
	return !featureSet.isEnabled(Feature.wildcard_variables);
	}
	return true;
	}
	}

	class LocalScope extends EnclosedScope {
	LocalScope(super.parent);

	void add(Element element) {
	if (!element.isWildcardVariable) {
	_addGetter(element);
	}
	}
	}

	class PrefixScope implements Scope {
	final LibraryElementImpl libraryElement;
	final PrefixScope? parent;

	final Map<String, Element> _getters = {};
	final Map<String, Element> _setters = {};
	Set<String>? _settersFromDeprecatedExport;
	Set<String>? _gettersFromDeprecatedExport;
	final Set<ExtensionElement> _extensions = {};
	LibraryElement? _deferredLibrary;

	PrefixScope({
	required this.libraryElement,
	required this.parent,
	required List<LibraryImportElement> libraryImports,
	required PrefixElement? prefix,
	}) {
	var elementFactory = libraryElement.session.elementFactory;
	for (var import in libraryImports) {
	var importedUri = import.uri;
	if (importedUri is DirectiveUriWithLibrary &&
	import.prefix?.element == prefix) {
	var importedLibrary = importedUri.library;
	if (importedLibrary is LibraryElementImpl) {
	var combinators = import.combinators.build();
	for (var exportedReference in importedLibrary.exportedReferences) {
	var reference = exportedReference.reference;
	if (combinators.allows(reference.name)) {
	var element = elementFactory.elementOfReference(reference)!;
	if (_shouldAdd(importedLibrary, element)) {
	_add(
	element,
	importedLibrary.isFromDeprecatedExport(exportedReference),
	);
	}
	}
	}
	if (import.prefix is DeferredImportElementPrefix) {
	_deferredLibrary ??= importedLibrary;
	}
	}
	}
	}
	}

	@override
	ScopeLookupResult lookup(String id) {
	var deferredLibrary = _deferredLibrary;
	if (deferredLibrary != null && id == FunctionElement.LOAD_LIBRARY_NAME) {
	return ScopeLookupResultImpl(deferredLibrary.loadLibraryFunction, null);
	}

	var getter = _getters[id];
	var setter = _setters[id];
	if (getter != null \|\| setter != null) {
	return PrefixScopeLookupResult(
	getter,
	setter,
	_gettersFromDeprecatedExport?.contains(id) ?? false,
	_settersFromDeprecatedExport?.contains(id) ?? false,
	);
	}

	if (parent case var parent?) {
	return parent.lookup(id);
	}

	return ScopeLookupResultImpl(null, null);
	}

	void _add(Element element, bool isFromDeprecatedExport) {
	if (element is PropertyAccessorElement && element.isSetter) {
	_addTo(
	element,
	isFromDeprecatedExport: isFromDeprecatedExport,
	isSetter: true,
	);
	} else {
	_addTo(
	element,
	isFromDeprecatedExport: isFromDeprecatedExport,
	isSetter: false,
	);
	if (element is ExtensionElement) {
	_extensions.add(element);
	}
	}
	}

	void _addTo(
	Element element, {
	required bool isFromDeprecatedExport,
	required bool isSetter,
	}) {
	var map = isSetter ? _setters : _getters;
	var id = element.displayName;
	var existing = map[id];

	if (existing == null) {
	map[id] = element;
	if (isFromDeprecatedExport) {
	if (isSetter) {
	(_settersFromDeprecatedExport ??= {}).add(id);
	} else {
	(_gettersFromDeprecatedExport ??= {}).add(id);
	}
	}
	return;
	}

	var deprecatedSet =
	isSetter ? _settersFromDeprecatedExport : _gettersFromDeprecatedExport;
	var wasFromDeprecatedExport = deprecatedSet?.contains(id) ?? false;
	if (existing == element) {
	if (wasFromDeprecatedExport && !isFromDeprecatedExport) {
	deprecatedSet!.remove(id);
	}
	return;
	}

	map[id] = _merge(existing, element);
	if (wasFromDeprecatedExport) {
	deprecatedSet!.remove(id);
	}
	}

	Element _merge(Element existing, Element other) {
	if (_isSdkElement(existing)) {
	if (!_isSdkElement(other)) {
	return other;
	}
	} else {
	if (_isSdkElement(other)) {
	return existing;
	}
	}

	var conflictingElements = <Element>{};
	_addElement(conflictingElements, existing);
	_addElement(conflictingElements, other);

	return MultiplyDefinedElementImpl(
	libraryElement.context,
	libraryElement.session,
	conflictingElements.first.name!,
	conflictingElements.toList(),
	);
	}

	bool _shouldAdd(LibraryElementImpl importedLibrary, Element element) {
	// It is an error for the identifier `Record`, denoting the `Record` class
	// from `dart:core`, where that import scope name is only imported from
	// platform libraries, to appear in a library whose language version is
	// less than `v`; assuming that `v` is the language version in which
	// records are released.
	if (!libraryElement.featureSet.isEnabled(Feature.records)) {
	if (importedLibrary.isInSdk &&
	element is ClassElementImpl &&
	element.isDartCoreRecord) {
	return false;
	}
	}
	return true;
	}

	static void _addElement(
	Set<Element> conflictingElements,
	Element element,
	) {
	if (element is MultiplyDefinedElementImpl) {
	conflictingElements.addAll(element.conflictingElements);
	} else {
	conflictingElements.add(element);
	}
	}

	static bool _isSdkElement(Element element) {
	if (element is DynamicElementImpl \|\| element is NeverElementImpl) {
	return true;
	}
	if (element is MultiplyDefinedElement) {
	return false;
	}
	return element.library!.isInSdk;
	}
	}

	class PrefixScopeLookupResult extends ScopeLookupResultImpl {
	static const int getterIsFromDeprecatedExportBit = 1 << 0;
	static const int setterIsFromDeprecatedExportBit = 1 << 1;

	final int _deprecatedBits;

	PrefixScopeLookupResult(
	super.importedGetter,
	super.importedSetter,
	bool getterIsFromDeprecatedExport,
	bool setterIsFromDeprecatedExport,
	) : _deprecatedBits = (getterIsFromDeprecatedExport
	? getterIsFromDeprecatedExportBit
	: 0) \|
	(setterIsFromDeprecatedExport
	? setterIsFromDeprecatedExportBit
	: 0);

	/// This flag is set to `true` if [getter] is available using import
	/// directives where every imported library re-exports the element, and
	/// every such `export` directive is marked as deprecated.
	bool get getterIsFromDeprecatedExport =>
	(_deprecatedBits & getterIsFromDeprecatedExportBit) != 0;

	/// This flag is set to `true` if [setter] is available using import
	/// directives where every imported library re-exports the element, and
	/// every such `export` directive is marked as deprecated.
	bool get setterIsFromDeprecatedExport =>
	(_deprecatedBits & setterIsFromDeprecatedExportBit) != 0;
	}

	class ScopeLookupResultImpl implements ScopeLookupResult {
	@override
	final Element? getter;

	@override
	final Element? setter;

	ScopeLookupResultImpl(this.getter, this.setter);
	}

	class TypeParameterScope extends EnclosedScope {
	TypeParameterScope(
	super.parent,
	List<TypeParameterElement> elements,
	) {
	for (var element in elements) {
	if (!element.isWildcardVariable) {
	_addGetter(element);
	}
	}
	}
	}

	mixin _GettersAndSetters {
	final Map<String, Element> _getters = {};
	final Map<String, Element> _setters = {};

	void _addGetter(Element element) {
	var id = element.name;
	if (id != null) {
	_getters[id] ??= element;
	}
	}

	void _addPropertyAccessor(PropertyAccessorElement element) {
	if (element.isGetter) {
	_addGetter(element);
	} else {
	_addSetter(element);
	}
	}

	void _addSetter(Element element) {
	var name = element.name;
	if (name != null && name.endsWith('=')) {
	var id = considerCanonicalizeString(name.substring(0, name.length - 1));
	_setters[id] ??= element;
	}
	}
	}