pkg/analysis_server/lib/src/services/completion/dart/completion_manager.dart - sdk.git - Git at Google

 // Copyright (c) 2015, 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:analysis_server/src/protocol_server.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart';
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/services/completion/dart/arglist_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/combinator_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/documentation_cache.dart';
 import 'package:analysis_server/src/services/completion/dart/extension_member_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/feature_computer.dart';
 import 'package:analysis_server/src/services/completion/dart/field_formal_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/imported_reference_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/keyword_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/label_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/library_member_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/library_prefix_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/local_library_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/local_reference_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/named_constructor_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/not_imported_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/override_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/redirecting_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/relevance_tables.g.dart';
 import 'package:analysis_server/src/services/completion/dart/static_member_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/suggestion_builder.dart';
 import 'package:analysis_server/src/services/completion/dart/type_member_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/uri_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/variable_name_contributor.dart';
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/analysis/session.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/dart/analysis/driver_based_analysis_context.dart';
 import 'package:analyzer/src/dartdoc/dartdoc_directive_info.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/util/file_paths.dart' as file_paths;
 import 'package:analyzer/src/util/performance/operation_performance.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart' as protocol;
 import 'package:analyzer_plugin/src/utilities/completion/completion_target.dart';
 import 'package:analyzer_plugin/src/utilities/completion/optype.dart';

 /// Class that tracks how much time budget we have left.
 class CompletionBudget {
   final Duration _budget;
   final Stopwatch _timer = Stopwatch()..start();

   CompletionBudget(this._budget);

   Duration get left {
     var result = _budget - _timer.elapsed;
     return result.isNegative ? Duration.zero : result;
   }
 }

 /// [DartCompletionManager] determines if a completion request is Dart specific
 /// and forwards those requests to all [DartCompletionContributor]s.
 class DartCompletionManager {
   /// If not `null`, then instead of using [ImportedReferenceContributor],
   /// fill this set with kinds of elements that are applicable at the
   /// completion location, so should be suggested from available suggestion
   /// sets.
   final Set<protocol.ElementKind>? includedElementKinds;

   /// If [includedElementKinds] is not null, must be also not `null`, and
   /// will be filled with names of all top-level declarations from all
   /// included suggestion sets.
   final Set<String>? includedElementNames;

   /// If [includedElementKinds] is not null, must be also not `null`, and
   /// will be filled with tags for suggestions that should be given higher
   /// relevance than other included suggestions.
   final List<IncludedSuggestionRelevanceTag>? includedSuggestionRelevanceTags;

   /// The listener to be notified at certain points in the process of building
   /// suggestions, or `null` if no notification should occur.
   final SuggestionListener? listener;

   /// If specified, will be filled with URIs of libraries that are not yet
   /// imported, but could be imported into the requested target. Corresponding
   /// [CompletionSuggestion] will have the import index into this list.
   final List<Uri>? librariesToImport;

   /// Initialize a newly created completion manager. The parameters
   /// [includedElementKinds], [includedElementNames], and
   /// [includedSuggestionRelevanceTags] must either all be `null` or must all be
   /// non-`null`.
   DartCompletionManager({
     this.includedElementKinds,
     this.includedElementNames,
     this.includedSuggestionRelevanceTags,
     this.listener,
     this.librariesToImport,
   }) : assert((includedElementKinds != null &&
                 includedElementNames != null &&
                 includedSuggestionRelevanceTags != null) ||
             (includedElementKinds == null &&
                 includedElementNames == null &&
                 includedSuggestionRelevanceTags == null));

   Future<List<CompletionSuggestion>> computeSuggestions(
     DartCompletionRequest request,
     OperationPerformanceImpl performance, {
     bool enableOverrideContributor = true,
     bool enableUriContributor = true,
   }) async {
     request.checkAborted();
     var pathContext = request.resourceProvider.pathContext;
     if (!file_paths.isDart(pathContext, request.result.path)) {
       return const <CompletionSuggestion>[];
     }

     // Don't suggest in comments.
     if (request.target.isCommentText) {
       return const <CompletionSuggestion>[];
     }

     request.checkAborted();

     // Request Dart specific completions from each contributor
     var builder = SuggestionBuilder(request, listener: listener);
     var contributors = <DartCompletionContributor>[
       ArgListContributor(request, builder),
       CombinatorContributor(request, builder),
       ExtensionMemberContributor(request, builder),
       FieldFormalContributor(request, builder),
       KeywordContributor(request, builder),
       LabelContributor(request, builder),
       LibraryMemberContributor(request, builder),
       LibraryPrefixContributor(request, builder),
       LocalLibraryContributor(request, builder),
       LocalReferenceContributor(request, builder),
       NamedConstructorContributor(request, builder),
       if (enableOverrideContributor) OverrideContributor(request, builder),
       RedirectingContributor(request, builder),
       StaticMemberContributor(request, builder),
       TypeMemberContributor(request, builder),
       if (enableUriContributor) UriContributor(request, builder),
       VariableNameContributor(request, builder),
     ];

     if (includedElementKinds != null) {
       _addIncludedElementKinds(request);
       _addIncludedSuggestionRelevanceTags(request);
     } else {
       contributors.add(
         ImportedReferenceContributor(request, builder),
       );
     }

     final librariesToImport = this.librariesToImport;
     if (librariesToImport != null) {
       contributors.add(
         NotImportedContributor(request, builder, librariesToImport),
       );
     }

     try {
       for (var contributor in contributors) {
         await performance.runAsync(
           'DartCompletionManager - ${contributor.runtimeType}',
           (_) async {
             await contributor.computeSuggestions();
           },
         );
         request.checkAborted();
       }
     } on InconsistentAnalysisException {
       // The state of the code being analyzed has changed, so results are likely
       // to be inconsistent. Just abort the operation.
       throw AbortCompletion();
     }

     return builder.suggestions.toList();
   }

   void _addIncludedElementKinds(DartCompletionRequest request) {
     var opType = request.opType;

     if (!opType.includeIdentifiers) return;

     var kinds = includedElementKinds;
     if (kinds != null) {
       if (opType.includeConstructorSuggestions) {
         kinds.add(protocol.ElementKind.CONSTRUCTOR);
       }
       if (opType.includeTypeNameSuggestions) {
         kinds.add(protocol.ElementKind.CLASS);
         kinds.add(protocol.ElementKind.CLASS_TYPE_ALIAS);
         kinds.add(protocol.ElementKind.ENUM);
         kinds.add(protocol.ElementKind.FUNCTION_TYPE_ALIAS);
         kinds.add(protocol.ElementKind.MIXIN);
         kinds.add(protocol.ElementKind.TYPE_ALIAS);
       }
       if (opType.includeReturnValueSuggestions) {
         kinds.add(protocol.ElementKind.CONSTRUCTOR);
         kinds.add(protocol.ElementKind.ENUM_CONSTANT);
         kinds.add(protocol.ElementKind.EXTENSION);
         // Static fields.
         kinds.add(protocol.ElementKind.FIELD);
         kinds.add(protocol.ElementKind.FUNCTION);
         // Static and top-level properties.
         kinds.add(protocol.ElementKind.GETTER);
         kinds.add(protocol.ElementKind.SETTER);
         kinds.add(protocol.ElementKind.TOP_LEVEL_VARIABLE);
       }
     }
   }

   void _addIncludedSuggestionRelevanceTags(DartCompletionRequest request) {
     final includedSuggestionRelevanceTags =
         this.includedSuggestionRelevanceTags!;
     var location = request.opType.completionLocation;
     if (location != null) {
       var locationTable = elementKindRelevance[location];
       if (locationTable != null) {
         var inConstantContext = request.inConstantContext;
         for (var entry in locationTable.entries) {
           var kind = entry.key.toString();
           var elementBoost = (entry.value.upper * 100).floor();
           includedSuggestionRelevanceTags
               .add(IncludedSuggestionRelevanceTag(kind, elementBoost));
           if (inConstantContext) {
             includedSuggestionRelevanceTags.add(IncludedSuggestionRelevanceTag(
                 '$kind+const', elementBoost + 100));
           }
         }
       }
     }

     var type = request.contextType;
     if (type is InterfaceType) {
       var element = type.element;
       var tag = '${element.librarySource.uri}::${element.name}';
       if (element.isEnum) {
         includedSuggestionRelevanceTags.add(
           IncludedSuggestionRelevanceTag(
             tag,
             RelevanceBoost.availableEnumConstant,
           ),
         );
       } else {
         // TODO(brianwilkerson) This was previously used to boost exact type
         //  matches. For example, if the context type was `Foo`, then the class
         //  `Foo` and it's constructors would be given this boost. Now this
         //  boost will almost always be ignored because the element boost will
         //  be bigger. Find a way to use this boost without negating the element
         //  boost, which is how we get constructors to come before classes.
         includedSuggestionRelevanceTags.add(
           IncludedSuggestionRelevanceTag(
             tag,
             RelevanceBoost.availableDeclaration,
           ),
         );
       }
     }
   }
 }

 /// The information about a requested list of completions within a Dart file.
 class DartCompletionRequest {
   final CompletionPreference completionPreference;

   /// Return the type imposed on the target's `containingNode` based on its
   /// context, or `null` if the context does not impose any type.
   final DartType? contextType;

   /// Return the object used to resolve macros in Dartdoc comments.
   final DartdocDirectiveInfo dartdocDirectiveInfo;

   final DocumentationCache? documentationCache;

   /// Return the expression to the right of the "dot" or "dot dot",
   /// or `null` if this is not a "dot" completion (e.g. `foo.b`).
   final Expression? dotTarget;

   /// Return the object used to compute the values of the features used to
   /// compute relevance scores for suggestions.
   final FeatureComputer featureComputer;

   /// Return the offset within the source at which the completion is being
   /// requested.
   final int offset;

   /// The [OpType] which describes which types of suggestions would fit the
   /// request.
   final OpType opType;

   /// The source range that represents the region of text that should be
   /// replaced when a suggestion is selected.
   final SourceRange replacementRange;

   /// The analysis result for the file in which the completion is being
   /// requested.
   final ResolvedUnitResult result;

   /// Return the source in which the completion is being requested.
   final Source source;

   /// Return the completion target.  This determines what part of the parse tree
   /// will receive the newly inserted text.
   /// At a minimum, all declarations in the completion scope in [target.unit]
   /// will be resolved if they can be resolved.
   final CompletionTarget target;

   bool _aborted = false;

   factory DartCompletionRequest({
     required ResolvedUnitResult resolvedUnit,
     required int offset,
     DartdocDirectiveInfo? dartdocDirectiveInfo,
     CompletionPreference completionPreference = CompletionPreference.insert,
     DocumentationCache? documentationCache,
   }) {
     var target = CompletionTarget.forOffset(resolvedUnit.unit, offset);
     var dotTarget = _dotTarget(target);

     var featureComputer = FeatureComputer(
       resolvedUnit.typeSystem,
       resolvedUnit.typeProvider,
     );

     var contextType = featureComputer.computeContextType(
       target.containingNode,
       offset,
     );

     var opType = OpType.forCompletion(target, offset);
     if (contextType != null && contextType.isVoid) {
       opType.includeVoidReturnSuggestions = true;
     }

     return DartCompletionRequest._(
       completionPreference: completionPreference,
       contextType: contextType,
       dartdocDirectiveInfo: dartdocDirectiveInfo ?? DartdocDirectiveInfo(),
       documentationCache: documentationCache,
       dotTarget: dotTarget,
       featureComputer: featureComputer,
       offset: offset,
       opType: opType,
       replacementRange: target.computeReplacementRange(offset),
       result: resolvedUnit,
       source: resolvedUnit.unit.declaredElement!.source,
       target: target,
     );
   }

   DartCompletionRequest._({
     required this.completionPreference,
     required this.contextType,
     required this.dartdocDirectiveInfo,
     required this.documentationCache,
     required this.dotTarget,
     required this.featureComputer,
     required this.offset,
     required this.opType,
     required this.replacementRange,
     required this.result,
     required this.source,
     required this.target,
   });

   /// Return the feature set that was used to analyze the compilation unit in
   /// which suggestions are being made.
   FeatureSet get featureSet => libraryElement.featureSet;

   /// Return `true` if free standing identifiers should be suggested
   bool get includeIdentifiers {
     return opType.includeIdentifiers;
   }

   /// Return `true` if the completion is occurring in a constant context.
   bool get inConstantContext {
     var entity = target.entity;
     return entity is Expression && entity.inConstantContext;
   }

   /// Return the library element which contains the unit in which the completion
   /// is occurring.
   LibraryElement get libraryElement => result.libraryElement;

   /// Answer the [DartType] for Object in dart:core
   DartType get objectType => libraryElement.typeProvider.objectType;

   /// The length of the text to be replaced if the remainder of the identifier
   /// containing the cursor is to be replaced when the suggestion is applied
   /// (that is, the number of characters in the existing identifier).
   /// This will be different than the [replacementOffset] - [offset]
   /// if the [offset] is in the middle of an existing identifier.
   int get replacementLength => replacementRange.length;

   /// The offset of the start of the text to be replaced.
   /// This will be different than the [offset] used to request the completion
   /// suggestions if there was a portion of an identifier before the original
   /// [offset]. In particular, the [replacementOffset] will be the offset of the
   /// beginning of said identifier.
   int get replacementOffset => replacementRange.offset;

   /// Return the resource provider associated with this request.
   ResourceProvider get resourceProvider => result.session.resourceProvider;

   /// Return the content of the [source] in which the completion is being
   /// requested, or `null` if the content could not be accessed.
   String? get sourceContents => result.content;

   /// Return the [SourceFactory] of the request.
   SourceFactory get sourceFactory {
     var context = result.session.analysisContext as DriverBasedAnalysisContext;
     return context.driver.sourceFactory;
   }

   /// Return prefix that already exists in the document for [target] or empty
   /// string if unavailable. This can be used to filter the completion list to
   /// items that already match the text to the left of the caret.
   String get targetPrefix {
     var entity = target.entity;

     if (entity is Token) {
       var prev = entity.previous;
       if (prev != null && prev.end == offset && prev.isKeywordOrIdentifier) {
         return prev.lexeme;
       }
     }

     while (entity is AstNode) {
       if (entity is SimpleIdentifier) {
         var identifier = entity.name;
         if (offset >= entity.offset && offset < entity.end) {
           return identifier.substring(0, offset - entity.offset);
         } else if (offset == entity.end) {
           return identifier;
         }
       }
       var children = entity.childEntities;
       entity = children.isEmpty ? null : children.first;
     }
     return '';
   }

   /// Abort the current completion request.
   void abort() {
     _aborted = true;
   }

   /// Throw [AbortCompletion] if the completion request has been aborted.
   void checkAborted() {
     if (_aborted) {
       throw AbortCompletion();
     }
   }

   /// TODO(scheglov) Should this be a property of [CompletionTarget]?
   static Expression? _dotTarget(CompletionTarget target) {
     var node = target.containingNode;
     var offset = target.offset;
     if (node is MethodInvocation) {
       if (identical(node.methodName, target.entity)) {
         return node.realTarget;
       } else if (node.isCascaded && node.operator!.offset + 1 == offset) {
         return node.realTarget;
       }
     }
     if (node is PropertyAccess) {
       if (identical(node.propertyName, target.entity)) {
         return node.realTarget;
       } else if (node.isCascaded && node.operator.offset + 1 == offset) {
         return node.realTarget;
       }
     }
     if (node is PrefixedIdentifier) {
       if (identical(node.identifier, target.entity)) {
         return node.prefix;
       }
     }
   }
 }
	// Copyright (c) 2015, 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:analysis_server/src/protocol_server.dart';
	import 'package:analysis_server/src/provisional/completion/completion_core.dart';
	import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
	import 'package:analysis_server/src/services/completion/dart/arglist_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/combinator_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/documentation_cache.dart';
	import 'package:analysis_server/src/services/completion/dart/extension_member_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/feature_computer.dart';
	import 'package:analysis_server/src/services/completion/dart/field_formal_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/imported_reference_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/keyword_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/label_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/library_member_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/library_prefix_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/local_library_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/local_reference_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/named_constructor_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/not_imported_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/override_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/redirecting_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/relevance_tables.g.dart';
	import 'package:analysis_server/src/services/completion/dart/static_member_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/suggestion_builder.dart';
	import 'package:analysis_server/src/services/completion/dart/type_member_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/uri_contributor.dart';
	import 'package:analysis_server/src/services/completion/dart/variable_name_contributor.dart';
	import 'package:analyzer/dart/analysis/features.dart';
	import 'package:analyzer/dart/analysis/results.dart';
	import 'package:analyzer/dart/analysis/session.dart';
	import 'package:analyzer/dart/ast/ast.dart';
	import 'package:analyzer/dart/ast/token.dart';
	import 'package:analyzer/dart/element/element.dart';
	import 'package:analyzer/dart/element/type.dart';
	import 'package:analyzer/file_system/file_system.dart';
	import 'package:analyzer/src/dart/analysis/driver_based_analysis_context.dart';
	import 'package:analyzer/src/dartdoc/dartdoc_directive_info.dart';
	import 'package:analyzer/src/generated/source.dart';
	import 'package:analyzer/src/util/file_paths.dart' as file_paths;
	import 'package:analyzer/src/util/performance/operation_performance.dart';
	import 'package:analyzer_plugin/protocol/protocol_common.dart' as protocol;
	import 'package:analyzer_plugin/src/utilities/completion/completion_target.dart';
	import 'package:analyzer_plugin/src/utilities/completion/optype.dart';

	/// Class that tracks how much time budget we have left.
	class CompletionBudget {
	final Duration _budget;
	final Stopwatch _timer = Stopwatch()..start();

	CompletionBudget(this._budget);

	Duration get left {
	var result = _budget - _timer.elapsed;
	return result.isNegative ? Duration.zero : result;
	}
	}

	/// [DartCompletionManager] determines if a completion request is Dart specific
	/// and forwards those requests to all [DartCompletionContributor]s.
	class DartCompletionManager {
	/// If not `null`, then instead of using [ImportedReferenceContributor],
	/// fill this set with kinds of elements that are applicable at the
	/// completion location, so should be suggested from available suggestion
	/// sets.
	final Set<protocol.ElementKind>? includedElementKinds;

	/// If [includedElementKinds] is not null, must be also not `null`, and
	/// will be filled with names of all top-level declarations from all
	/// included suggestion sets.
	final Set<String>? includedElementNames;

	/// If [includedElementKinds] is not null, must be also not `null`, and
	/// will be filled with tags for suggestions that should be given higher
	/// relevance than other included suggestions.
	final List<IncludedSuggestionRelevanceTag>? includedSuggestionRelevanceTags;

	/// The listener to be notified at certain points in the process of building
	/// suggestions, or `null` if no notification should occur.
	final SuggestionListener? listener;

	/// If specified, will be filled with URIs of libraries that are not yet
	/// imported, but could be imported into the requested target. Corresponding
	/// [CompletionSuggestion] will have the import index into this list.
	final List<Uri>? librariesToImport;

	/// Initialize a newly created completion manager. The parameters
	/// [includedElementKinds], [includedElementNames], and
	/// [includedSuggestionRelevanceTags] must either all be `null` or must all be
	/// non-`null`.
	DartCompletionManager({
	this.includedElementKinds,
	this.includedElementNames,
	this.includedSuggestionRelevanceTags,
	this.listener,
	this.librariesToImport,
	}) : assert((includedElementKinds != null &&
	includedElementNames != null &&
	includedSuggestionRelevanceTags != null) \|\|
	(includedElementKinds == null &&
	includedElementNames == null &&
	includedSuggestionRelevanceTags == null));

	Future<List<CompletionSuggestion>> computeSuggestions(
	DartCompletionRequest request,
	OperationPerformanceImpl performance, {
	bool enableOverrideContributor = true,
	bool enableUriContributor = true,
	}) async {
	request.checkAborted();
	var pathContext = request.resourceProvider.pathContext;
	if (!file_paths.isDart(pathContext, request.result.path)) {
	return const <CompletionSuggestion>[];
	}

	// Don't suggest in comments.
	if (request.target.isCommentText) {
	return const <CompletionSuggestion>[];
	}

	request.checkAborted();

	// Request Dart specific completions from each contributor
	var builder = SuggestionBuilder(request, listener: listener);
	var contributors = <DartCompletionContributor>[
	ArgListContributor(request, builder),
	CombinatorContributor(request, builder),
	ExtensionMemberContributor(request, builder),
	FieldFormalContributor(request, builder),
	KeywordContributor(request, builder),
	LabelContributor(request, builder),
	LibraryMemberContributor(request, builder),
	LibraryPrefixContributor(request, builder),
	LocalLibraryContributor(request, builder),
	LocalReferenceContributor(request, builder),
	NamedConstructorContributor(request, builder),
	if (enableOverrideContributor) OverrideContributor(request, builder),
	RedirectingContributor(request, builder),
	StaticMemberContributor(request, builder),
	TypeMemberContributor(request, builder),
	if (enableUriContributor) UriContributor(request, builder),
	VariableNameContributor(request, builder),
	];

	if (includedElementKinds != null) {
	_addIncludedElementKinds(request);
	_addIncludedSuggestionRelevanceTags(request);
	} else {
	contributors.add(
	ImportedReferenceContributor(request, builder),
	);
	}

	final librariesToImport = this.librariesToImport;
	if (librariesToImport != null) {
	contributors.add(
	NotImportedContributor(request, builder, librariesToImport),
	);
	}

	try {
	for (var contributor in contributors) {
	await performance.runAsync(
	'DartCompletionManager - ${contributor.runtimeType}',
	(_) async {
	await contributor.computeSuggestions();
	},
	);
	request.checkAborted();
	}
	} on InconsistentAnalysisException {
	// The state of the code being analyzed has changed, so results are likely
	// to be inconsistent. Just abort the operation.
	throw AbortCompletion();
	}

	return builder.suggestions.toList();
	}

	void _addIncludedElementKinds(DartCompletionRequest request) {
	var opType = request.opType;

	if (!opType.includeIdentifiers) return;

	var kinds = includedElementKinds;
	if (kinds != null) {
	if (opType.includeConstructorSuggestions) {
	kinds.add(protocol.ElementKind.CONSTRUCTOR);
	}
	if (opType.includeTypeNameSuggestions) {
	kinds.add(protocol.ElementKind.CLASS);
	kinds.add(protocol.ElementKind.CLASS_TYPE_ALIAS);
	kinds.add(protocol.ElementKind.ENUM);
	kinds.add(protocol.ElementKind.FUNCTION_TYPE_ALIAS);
	kinds.add(protocol.ElementKind.MIXIN);
	kinds.add(protocol.ElementKind.TYPE_ALIAS);
	}
	if (opType.includeReturnValueSuggestions) {
	kinds.add(protocol.ElementKind.CONSTRUCTOR);
	kinds.add(protocol.ElementKind.ENUM_CONSTANT);
	kinds.add(protocol.ElementKind.EXTENSION);
	// Static fields.
	kinds.add(protocol.ElementKind.FIELD);
	kinds.add(protocol.ElementKind.FUNCTION);
	// Static and top-level properties.
	kinds.add(protocol.ElementKind.GETTER);
	kinds.add(protocol.ElementKind.SETTER);
	kinds.add(protocol.ElementKind.TOP_LEVEL_VARIABLE);
	}
	}
	}

	void _addIncludedSuggestionRelevanceTags(DartCompletionRequest request) {
	final includedSuggestionRelevanceTags =
	this.includedSuggestionRelevanceTags!;
	var location = request.opType.completionLocation;
	if (location != null) {
	var locationTable = elementKindRelevance[location];
	if (locationTable != null) {
	var inConstantContext = request.inConstantContext;
	for (var entry in locationTable.entries) {
	var kind = entry.key.toString();
	var elementBoost = (entry.value.upper * 100).floor();
	includedSuggestionRelevanceTags
	.add(IncludedSuggestionRelevanceTag(kind, elementBoost));
	if (inConstantContext) {
	includedSuggestionRelevanceTags.add(IncludedSuggestionRelevanceTag(
	'$kind+const', elementBoost + 100));
	}
	}
	}
	}

	var type = request.contextType;
	if (type is InterfaceType) {
	var element = type.element;
	var tag = '${element.librarySource.uri}::${element.name}';
	if (element.isEnum) {
	includedSuggestionRelevanceTags.add(
	IncludedSuggestionRelevanceTag(
	tag,
	RelevanceBoost.availableEnumConstant,
	),
	);
	} else {
	// TODO(brianwilkerson) This was previously used to boost exact type
	// matches. For example, if the context type was `Foo`, then the class
	// `Foo` and it's constructors would be given this boost. Now this
	// boost will almost always be ignored because the element boost will
	// be bigger. Find a way to use this boost without negating the element
	// boost, which is how we get constructors to come before classes.
	includedSuggestionRelevanceTags.add(
	IncludedSuggestionRelevanceTag(
	tag,
	RelevanceBoost.availableDeclaration,
	),
	);
	}
	}
	}
	}

	/// The information about a requested list of completions within a Dart file.
	class DartCompletionRequest {
	final CompletionPreference completionPreference;

	/// Return the type imposed on the target's `containingNode` based on its
	/// context, or `null` if the context does not impose any type.
	final DartType? contextType;

	/// Return the object used to resolve macros in Dartdoc comments.
	final DartdocDirectiveInfo dartdocDirectiveInfo;

	final DocumentationCache? documentationCache;

	/// Return the expression to the right of the "dot" or "dot dot",
	/// or `null` if this is not a "dot" completion (e.g. `foo.b`).
	final Expression? dotTarget;

	/// Return the object used to compute the values of the features used to
	/// compute relevance scores for suggestions.
	final FeatureComputer featureComputer;

	/// Return the offset within the source at which the completion is being
	/// requested.
	final int offset;

	/// The [OpType] which describes which types of suggestions would fit the
	/// request.
	final OpType opType;

	/// The source range that represents the region of text that should be
	/// replaced when a suggestion is selected.
	final SourceRange replacementRange;

	/// The analysis result for the file in which the completion is being
	/// requested.
	final ResolvedUnitResult result;

	/// Return the source in which the completion is being requested.
	final Source source;

	/// Return the completion target. This determines what part of the parse tree
	/// will receive the newly inserted text.
	/// At a minimum, all declarations in the completion scope in [target.unit]
	/// will be resolved if they can be resolved.
	final CompletionTarget target;

	bool _aborted = false;

	factory DartCompletionRequest({
	required ResolvedUnitResult resolvedUnit,
	required int offset,
	DartdocDirectiveInfo? dartdocDirectiveInfo,
	CompletionPreference completionPreference = CompletionPreference.insert,
	DocumentationCache? documentationCache,
	}) {
	var target = CompletionTarget.forOffset(resolvedUnit.unit, offset);
	var dotTarget = _dotTarget(target);

	var featureComputer = FeatureComputer(
	resolvedUnit.typeSystem,
	resolvedUnit.typeProvider,
	);

	var contextType = featureComputer.computeContextType(
	target.containingNode,
	offset,
	);

	var opType = OpType.forCompletion(target, offset);
	if (contextType != null && contextType.isVoid) {
	opType.includeVoidReturnSuggestions = true;
	}

	return DartCompletionRequest._(
	completionPreference: completionPreference,
	contextType: contextType,
	dartdocDirectiveInfo: dartdocDirectiveInfo ?? DartdocDirectiveInfo(),
	documentationCache: documentationCache,
	dotTarget: dotTarget,
	featureComputer: featureComputer,
	offset: offset,
	opType: opType,
	replacementRange: target.computeReplacementRange(offset),
	result: resolvedUnit,
	source: resolvedUnit.unit.declaredElement!.source,
	target: target,
	);
	}

	DartCompletionRequest._({
	required this.completionPreference,
	required this.contextType,
	required this.dartdocDirectiveInfo,
	required this.documentationCache,
	required this.dotTarget,
	required this.featureComputer,
	required this.offset,
	required this.opType,
	required this.replacementRange,
	required this.result,
	required this.source,
	required this.target,
	});

	/// Return the feature set that was used to analyze the compilation unit in
	/// which suggestions are being made.
	FeatureSet get featureSet => libraryElement.featureSet;

	/// Return `true` if free standing identifiers should be suggested
	bool get includeIdentifiers {
	return opType.includeIdentifiers;
	}

	/// Return `true` if the completion is occurring in a constant context.
	bool get inConstantContext {
	var entity = target.entity;
	return entity is Expression && entity.inConstantContext;
	}

	/// Return the library element which contains the unit in which the completion
	/// is occurring.
	LibraryElement get libraryElement => result.libraryElement;

	/// Answer the [DartType] for Object in dart:core
	DartType get objectType => libraryElement.typeProvider.objectType;

	/// The length of the text to be replaced if the remainder of the identifier
	/// containing the cursor is to be replaced when the suggestion is applied
	/// (that is, the number of characters in the existing identifier).
	/// This will be different than the [replacementOffset] - [offset]
	/// if the [offset] is in the middle of an existing identifier.
	int get replacementLength => replacementRange.length;

	/// The offset of the start of the text to be replaced.
	/// This will be different than the [offset] used to request the completion
	/// suggestions if there was a portion of an identifier before the original
	/// [offset]. In particular, the [replacementOffset] will be the offset of the
	/// beginning of said identifier.
	int get replacementOffset => replacementRange.offset;

	/// Return the resource provider associated with this request.
	ResourceProvider get resourceProvider => result.session.resourceProvider;

	/// Return the content of the [source] in which the completion is being
	/// requested, or `null` if the content could not be accessed.
	String? get sourceContents => result.content;

	/// Return the [SourceFactory] of the request.
	SourceFactory get sourceFactory {
	var context = result.session.analysisContext as DriverBasedAnalysisContext;
	return context.driver.sourceFactory;
	}

	/// Return prefix that already exists in the document for [target] or empty
	/// string if unavailable. This can be used to filter the completion list to
	/// items that already match the text to the left of the caret.
	String get targetPrefix {
	var entity = target.entity;

	if (entity is Token) {
	var prev = entity.previous;
	if (prev != null && prev.end == offset && prev.isKeywordOrIdentifier) {
	return prev.lexeme;
	}
	}

	while (entity is AstNode) {
	if (entity is SimpleIdentifier) {
	var identifier = entity.name;
	if (offset >= entity.offset && offset < entity.end) {
	return identifier.substring(0, offset - entity.offset);
	} else if (offset == entity.end) {
	return identifier;
	}
	}
	var children = entity.childEntities;
	entity = children.isEmpty ? null : children.first;
	}
	return '';
	}

	/// Abort the current completion request.
	void abort() {
	_aborted = true;
	}

	/// Throw [AbortCompletion] if the completion request has been aborted.
	void checkAborted() {
	if (_aborted) {
	throw AbortCompletion();
	}
	}

	/// TODO(scheglov) Should this be a property of [CompletionTarget]?
	static Expression? _dotTarget(CompletionTarget target) {
	var node = target.containingNode;
	var offset = target.offset;
	if (node is MethodInvocation) {
	if (identical(node.methodName, target.entity)) {
	return node.realTarget;
	} else if (node.isCascaded && node.operator!.offset + 1 == offset) {
	return node.realTarget;
	}
	}
	if (node is PropertyAccess) {
	if (identical(node.propertyName, target.entity)) {
	return node.realTarget;
	} else if (node.isCascaded && node.operator.offset + 1 == offset) {
	return node.realTarget;
	}
	}
	if (node is PrefixedIdentifier) {
	if (identical(node.identifier, target.entity)) {
	return node.prefix;
	}
	}
	}
	}