blob: dd370496d738e48256138eb017c0336986400c8a [file] [log] [blame]
// 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:analyzer/dart/ast/ast.dart';
import 'package:analyzer/dart/ast/visitor.dart';
import 'package:analyzer/dart/element/element.dart';
import 'package:analyzer/src/dart/ast/extensions.dart';
/// An object used to locate the [Element] associated with a given [AstNode].
class ElementLocator {
/// Return the element associated with the given [node], or `null` if there
/// is no element associated with the node.
static Element? locate(AstNode? node) {
if (node == null) return null;
var mapper = _ElementMapper();
return node.accept(mapper);
}
}
/// Visitor that maps nodes to elements.
class _ElementMapper extends GeneralizingAstVisitor<Element> {
@override
Element? visitAnnotation(Annotation node) {
return node.element;
}
@override
Element? visitAssignmentExpression(AssignmentExpression node) {
return node.staticElement;
}
@override
Element? visitBinaryExpression(BinaryExpression node) {
return node.staticElement;
}
@override
Element? visitClassDeclaration(ClassDeclaration node) {
return node.declaredElement;
}
@override
Element? visitCompilationUnit(CompilationUnit node) {
return node.declaredElement;
}
@override
Element? visitConstructorDeclaration(ConstructorDeclaration node) {
return node.declaredElement;
}
@override
Element? visitConstructorSelector(ConstructorSelector node) {
var parent = node.parent;
if (parent is EnumConstantArguments) {
var parent2 = parent.parent;
if (parent2 is EnumConstantDeclaration) {
return parent2.constructorElement;
}
}
return null;
}
@override
Element? visitExportDirective(ExportDirective node) {
return node.element;
}
@override
Element? visitFunctionDeclaration(FunctionDeclaration node) {
return node.declaredElement;
}
@override
Element? visitIdentifier(Identifier node) {
var parent = node.parent;
if (parent is Annotation) {
// Type name in Annotation
if (identical(parent.name, node) && parent.constructorName == null) {
return parent.element;
}
} else if (parent is ConstructorDeclaration) {
// Extra work to map Constructor Declarations to their associated
// Constructor Elements
var returnType = parent.returnType;
if (identical(returnType, node)) {
var name = parent.name;
if (name != null) {
return name.staticElement;
}
var element = node.staticElement;
if (element is ClassElement) {
return element.unnamedConstructor;
}
}
} else if (parent is LibraryIdentifier) {
var grandParent = parent.parent;
if (grandParent is PartOfDirective) {
var element = grandParent.element;
if (element is LibraryElement) {
return element.definingCompilationUnit;
}
} else if (grandParent is LibraryDirective) {
return grandParent.element;
}
}
return node.writeOrReadElement;
}
@override
Element? visitImportDirective(ImportDirective node) {
return node.element2;
}
@override
Element? visitIndexExpression(IndexExpression node) {
return node.staticElement;
}
@override
Element? visitInstanceCreationExpression(InstanceCreationExpression node) {
return node.constructorName.staticElement;
}
@override
Element? visitLibraryDirective(LibraryDirective node) {
return node.element;
}
@override
Element? visitMethodDeclaration(MethodDeclaration node) {
return node.declaredElement;
}
@override
Element? visitMethodInvocation(MethodInvocation node) {
return node.methodName.staticElement;
}
@override
Element? visitPartOfDirective(PartOfDirective node) {
return node.element;
}
@override
Element? visitPostfixExpression(PostfixExpression node) {
return node.staticElement;
}
@override
Element? visitPrefixedIdentifier(PrefixedIdentifier node) {
return node.staticElement;
}
@override
Element? visitPrefixExpression(PrefixExpression node) {
return node.staticElement;
}
@override
Element? visitStringLiteral(StringLiteral node) {
var parent = node.parent;
if (parent is UriBasedDirective) {
return parent.uriElement;
}
return null;
}
@override
Element? visitVariableDeclaration(VariableDeclaration node) {
return node.declaredElement;
}
}