Remove ReferencedNames(Builder).

pkg/analyzer/lib/src/task/dart.dart

Index: pkg/analyzer/lib/src/task/dart.dart
diff --git a/pkg/analyzer/lib/src/task/dart.dart b/pkg/analyzer/lib/src/task/dart.dart
index 6c999e4501dfe5748e0faf1dd01ed3ebf79c6a31..2de68f1957d9172236a914bee75a231d41491313 100644
--- a/pkg/analyzer/lib/src/task/dart.dart
+++ b/pkg/analyzer/lib/src/task/dart.dart
@@ -676,14 +676,6 @@ final ResultDescriptor<bool> READY_RESOLVED_UNIT =
     new ResultDescriptor<bool>('READY_RESOLVED_UNIT', false);
 
 /**
- * The names (resolved and not) referenced by a unit.
- *
- * The result is only available for [Source]s representing a compilation unit.
- */
-final ResultDescriptor<ReferencedNames> REFERENCED_NAMES =
-    new ResultDescriptor<ReferencedNames>('REFERENCED_NAMES', null);
-
-/**
  * The sources of the Dart files that a library references.
  *
  * The list is the union of [IMPORTED_LIBRARIES], [EXPORTED_LIBRARIES] and
@@ -3735,7 +3727,6 @@ class ParseDartTask extends SourceBasedAnalysisTask {
     LIBRARY_SPECIFIC_UNITS,
     PARSE_ERRORS,
     PARSED_UNIT,
-    REFERENCED_NAMES,
     REFERENCED_SOURCES,
     SOURCE_KIND,
     UNITS,
@@ -3851,11 +3842,6 @@ class ParseDartTask extends SourceBasedAnalysisTask {
       sourceKind = SourceKind.PART;
     }
     //
-    // Compute referenced names.
-    //
-    ReferencedNames referencedNames = new ReferencedNames(_source);
-    new ReferencedNamesBuilder(referencedNames).build(unit);
-    //
     // Compute source lists.
     //
     List<Source> explicitlyImportedSources =
@@ -3892,7 +3878,6 @@ class ParseDartTask extends SourceBasedAnalysisTask {
     outputs[LIBRARY_SPECIFIC_UNITS] = librarySpecificUnits;
     outputs[PARSE_ERRORS] = parseErrors;
     outputs[PARSED_UNIT] = unit;
-    outputs[REFERENCED_NAMES] = referencedNames;
     outputs[REFERENCED_SOURCES] = referencedSources.toList();
     outputs[SOURCE_KIND] = sourceKind;
     outputs[UNITS] = unitSources;
@@ -4266,408 +4251,6 @@ class ReadyResolvedUnitTask extends SourceBasedAnalysisTask {
 }
 
 /**
- * Information about a Dart [source] - which names it uses, which names it
- * defines with their externally visible dependencies.
- */
-class ReferencedNames {
-  final Source source;
-
-  /**
-   * The mapping from the name of a class to the set of names of other classes
-   * that extend, mix-in, or implement it.
-   *
-   * If the set of member of a class is changed, these changes might change
-   * the list of unimplemented inherited members in the class and classes that
-   * extend, mix-in, or implement it. So, we might need to report (or stop
-   * reporting) the corresponding warning.
-   */
-  final Map<String, Set<String>> superToSubs = <String, Set<String>>{};
-
-  /**
-   * The names of extended classes for which the unnamed constructor is
-   * invoked. Because we cannot use the name of the constructor to identify
-   * whether the unit is affected, we need to use the class name.
-   */
-  final Set<String> extendedUsedUnnamedConstructorNames = new Set<String>();
-
-  /**
-   * The names of instantiated classes.
-   *
-   * If one of these classes changes its set of members, it might change
-   * its list of unimplemented inherited members. So, we might need to report
-   * (or stop reporting) the corresponding warning.
-   */
-  final Set<String> instantiatedNames = new Set<String>();
-
-  /**
-   * The set of names that are referenced by the library, both inside and
-   * outside of method bodies.
-   */
-  final Set<String> names = new Set<String>();
-
-  /**
-   * The mapping from the name of a top-level element to the set of names that
-   * the element uses in a way that is visible outside of the element, e.g.
-   * the return type, or a parameter type.
-   */
-  final Map<String, Set<String>> userToDependsOn = <String, Set<String>>{};
-
-  ReferencedNames(this.source);
-
-  void addSubclass(String subName, String superName) {
-    superToSubs.putIfAbsent(superName, () => new Set<String>()).add(subName);
-  }
-}
-
-/**
- * A builder for creating [ReferencedNames].
- */
-class ReferencedNamesBuilder extends GeneralizingAstVisitor {
-  final Set<String> importPrefixNames = new Set<String>();
-  final ReferencedNames names;
-
-  String enclosingSuperClassName;
-  ReferencedNamesScope scope = new ReferencedNamesScope(null);
-
-  int localLevel = 0;
-  Set<String> dependsOn;
-
-  ReferencedNamesBuilder(this.names);
-
-  ReferencedNames build(CompilationUnit unit) {
-    unit.accept(this);
-    return names;
-  }
-
-  @override
-  visitBlock(Block node) {
-    ReferencedNamesScope outerScope = scope;
-    try {
-      scope = new ReferencedNamesScope.forBlock(scope, node);
-      super.visitBlock(node);
-    } finally {
-      scope = outerScope;
-    }
-  }
-
-  @override
-  visitClassDeclaration(ClassDeclaration node) {
-    ReferencedNamesScope outerScope = scope;
-    try {
-      scope = new ReferencedNamesScope.forClass(scope, node);
-      dependsOn = new Set<String>();
-      enclosingSuperClassName =
-          _getSimpleName(node.extendsClause?.superclass?.name);
-      super.visitClassDeclaration(node);
-      String className = node.name.name;
-      names.userToDependsOn[className] = dependsOn;
-      _addSuperName(className, node.extendsClause?.superclass);
-      _addSuperNames(className, node.withClause?.mixinTypes);
-      _addSuperNames(className, node.implementsClause?.interfaces);
-    } finally {
-      enclosingSuperClassName = null;
-      dependsOn = null;
-      scope = outerScope;
-    }
-  }
-
-  @override
-  visitClassTypeAlias(ClassTypeAlias node) {
-    ReferencedNamesScope outerScope = scope;
-    try {
-      scope = new ReferencedNamesScope.forClassTypeAlias(scope, node);
-      dependsOn = new Set<String>();
-      super.visitClassTypeAlias(node);
-      String className = node.name.name;
-      names.userToDependsOn[className] = dependsOn;
-      _addSuperName(className, node.superclass);
-      _addSuperNames(className, node.withClause?.mixinTypes);
-      _addSuperNames(className, node.implementsClause?.interfaces);
-    } finally {
-      dependsOn = null;
-      scope = outerScope;
-    }
-  }
-
-  @override
-  visitComment(Comment node) {
-    try {
-      localLevel++;
-      super.visitComment(node);
-    } finally {
-      localLevel--;
-    }
-  }
-
-  @override
-  visitConstructorName(ConstructorName node) {
-    if (node.parent is! ConstructorDeclaration) {
-      super.visitConstructorName(node);
-    }
-  }
-
-  @override
-  visitFunctionBody(FunctionBody node) {
-    try {
-      localLevel++;
-      super.visitFunctionBody(node);
-    } finally {
-      localLevel--;
-    }
-  }
-
-  @override
-  visitFunctionDeclaration(FunctionDeclaration node) {
-    if (localLevel == 0) {
-      ReferencedNamesScope outerScope = scope;
-      try {
-        scope = new ReferencedNamesScope.forFunction(scope, node);
-        dependsOn = new Set<String>();
-        super.visitFunctionDeclaration(node);
-        names.userToDependsOn[node.name.name] = dependsOn;
-      } finally {
-        dependsOn = null;
-        scope = outerScope;
-      }
-    } else {
-      super.visitFunctionDeclaration(node);
-    }
-  }
-
-  @override
-  visitFunctionTypeAlias(FunctionTypeAlias node) {
-    if (localLevel == 0) {
-      ReferencedNamesScope outerScope = scope;
-      try {
-        scope = new ReferencedNamesScope.forFunctionTypeAlias(scope, node);
-        dependsOn = new Set<String>();
-        super.visitFunctionTypeAlias(node);
-        names.userToDependsOn[node.name.name] = dependsOn;
-      } finally {
-        dependsOn = null;
-        scope = outerScope;
-      }
-    } else {
-      super.visitFunctionTypeAlias(node);
-    }
-  }
-
-  @override
-  visitImportDirective(ImportDirective node) {
-    if (node.prefix != null) {
-      importPrefixNames.add(node.prefix.name);
-    }
-    super.visitImportDirective(node);
-  }
-
-  @override
-  visitInstanceCreationExpression(InstanceCreationExpression node) {
-    ConstructorName constructorName = node.constructorName;
-    Identifier typeName = constructorName.type.name;
-    if (typeName is SimpleIdentifier) {
-      names.instantiatedNames.add(typeName.name);
-    }
-    if (typeName is PrefixedIdentifier) {
-      String prefixName = typeName.prefix.name;
-      if (importPrefixNames.contains(prefixName)) {
-        names.instantiatedNames.add(typeName.identifier.name);
-      } else {
-        names.instantiatedNames.add(prefixName);
-      }
-    }
-    super.visitInstanceCreationExpression(node);
-  }
-
-  @override
-  visitMethodDeclaration(MethodDeclaration node) {
-    ReferencedNamesScope outerScope = scope;
-    try {
-      scope = new ReferencedNamesScope.forMethod(scope, node);
-      super.visitMethodDeclaration(node);
-    } finally {
-      scope = outerScope;
-    }
-  }
-
-  @override
-  visitSimpleIdentifier(SimpleIdentifier node) {
-    // Ignore all declarations.
-    if (node.inDeclarationContext()) {
-      return;
-    }
-    // Ignore class names references from constructors.
-    AstNode parent = node.parent;
-    if (parent is ConstructorDeclaration && parent.returnType == node) {
-      return;
-    }
-    // Prepare name.
-    String name = node.name;
-    // Ignore unqualified names shadowed by local elements.
-    if (!node.isQualified) {
-      if (scope.contains(name)) {
-        return;
-      }
-      if (importPrefixNames.contains(name)) {
-        return;
-      }
-    }
-    // Do add the dependency.
-    names.names.add(name);
-    if (dependsOn != null && localLevel == 0) {
-      dependsOn.add(name);
-    }
-  }
-
-  @override
-  visitSuperConstructorInvocation(SuperConstructorInvocation node) {
-    if (node.constructorName == null && enclosingSuperClassName != null) {
-      names.extendedUsedUnnamedConstructorNames.add(enclosingSuperClassName);
-    }
-    super.visitSuperConstructorInvocation(node);
-  }
-
-  @override
-  visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
-    VariableDeclarationList variableList = node.variables;
-    // Prepare type dependencies.
-    Set<String> typeDependencies = new Set<String>();
-    dependsOn = typeDependencies;
-    variableList.type?.accept(this);
-    // Combine individual variable dependencies with the type dependencies.
-    for (VariableDeclaration variable in variableList.variables) {
-      dependsOn = new Set<String>();
-      variable.accept(this);
-      dependsOn.addAll(typeDependencies);
-      names.userToDependsOn[variable.name.name] = dependsOn;
-    }
-    dependsOn = null;
-  }
-
-  void _addSuperName(String className, TypeName type) {
-    if (type != null) {
-      Identifier typeName = type.name;
-      if (typeName is SimpleIdentifier) {
-        names.addSubclass(className, typeName.name);
-      }
-      if (typeName is PrefixedIdentifier) {
-        names.addSubclass(className, typeName.identifier.name);
-      }
-    }
-  }
-
-  void _addSuperNames(String className, List<TypeName> types) {
-    types?.forEach((type) => _addSuperName(className, type));
-  }
-
-  static String _getSimpleName(Identifier identifier) {
-    if (identifier is SimpleIdentifier) {
-      return identifier.name;
-    }
-    if (identifier is PrefixedIdentifier) {
-      return identifier.identifier.name;
-    }
-    return null;
-  }
-}
-
-class ReferencedNamesScope {
-  final ReferencedNamesScope enclosing;
-  Set<String> names;
-
-  ReferencedNamesScope(this.enclosing);
-
-  factory ReferencedNamesScope.forBlock(
-      ReferencedNamesScope enclosing, Block node) {
-    ReferencedNamesScope scope = new ReferencedNamesScope(enclosing);
-    for (Statement statement in node.statements) {
-      if (statement is FunctionDeclarationStatement) {
-        scope.add(statement.functionDeclaration.name.name);
-      } else if (statement is VariableDeclarationStatement) {
-        for (VariableDeclaration variable in statement.variables.variables) {
-          scope.add(variable.name.name);
-        }
-      }
-    }
-    return scope;
-  }
-
-  factory ReferencedNamesScope.forClass(
-      ReferencedNamesScope enclosing, ClassDeclaration node) {
-    ReferencedNamesScope scope = new ReferencedNamesScope(enclosing);
-    scope._addTypeParameters(node.typeParameters);
-    for (ClassMember member in node.members) {
-      if (member is FieldDeclaration) {
-        for (VariableDeclaration variable in member.fields.variables) {
-          scope.add(variable.name.name);
-        }
-      } else if (member is MethodDeclaration) {
-        scope.add(member.name.name);
-      }
-    }
-    return scope;
-  }
-
-  factory ReferencedNamesScope.forClassTypeAlias(
-      ReferencedNamesScope enclosing, ClassTypeAlias node) {
-    ReferencedNamesScope scope = new ReferencedNamesScope(enclosing);
-    scope._addTypeParameters(node.typeParameters);
-    return scope;
-  }
-
-  factory ReferencedNamesScope.forFunction(
-      ReferencedNamesScope enclosing, FunctionDeclaration node) {
-    ReferencedNamesScope scope = new ReferencedNamesScope(enclosing);
-    scope._addTypeParameters(node.functionExpression.typeParameters);
-    scope._addFormalParameters(node.functionExpression.parameters);
-    return scope;
-  }
-
-  factory ReferencedNamesScope.forFunctionTypeAlias(
-      ReferencedNamesScope enclosing, FunctionTypeAlias node) {
-    ReferencedNamesScope scope = new ReferencedNamesScope(enclosing);
-    scope._addTypeParameters(node.typeParameters);
-    return scope;
-  }
-
-  factory ReferencedNamesScope.forMethod(
-      ReferencedNamesScope enclosing, MethodDeclaration node) {
-    ReferencedNamesScope scope = new ReferencedNamesScope(enclosing);
-    scope._addTypeParameters(node.typeParameters);
-    scope._addFormalParameters(node.parameters);
-    return scope;
-  }
-
-  void add(String name) {
-    names ??= new Set<String>();
-    names.add(name);
-  }
-
-  bool contains(String name) {
-    if (names != null && names.contains(name)) {
-      return true;
-    }
-    if (enclosing != null) {
-      return enclosing.contains(name);
-    }
-    return false;
-  }
-
-  void _addFormalParameters(FormalParameterList parameterList) {
-    if (parameterList != null) {
-      parameterList.parameters
-          .map((p) => p is NormalFormalParameter ? p.identifier.name : '')
-          .forEach(add);
-    }
-  }
-
-  void _addTypeParameters(TypeParameterList typeParameterList) {
-    if (typeParameterList != null) {
-      typeParameterList.typeParameters.map((p) => p.name.name).forEach(add);
-    }
-  }
-}
-
-/**
  * A task that ensures that the expression AST for a constant is resolved and
  * sets the [CONSTANT_EXPRESSION_RESOLVED] result.
  */