blob: a11d0563e7d77cb21db8eb7a05e336f7bad80d38 [file] [log] [blame]
// Copyright (c) 2014, 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';
import 'package:analyzer/dart/ast/ast.dart';
import 'package:analyzer/dart/ast/ast_factory.dart';
import 'package:analyzer/dart/ast/standard_resolution_map.dart';
import 'package:analyzer/dart/ast/token.dart';
import 'package:analyzer/dart/ast/visitor.dart';
import 'package:analyzer/dart/element/element.dart';
import 'package:analyzer/dart/element/type.dart';
import 'package:analyzer/error/error.dart';
import 'package:analyzer/error/listener.dart';
import 'package:analyzer/exception/exception.dart';
import 'package:analyzer/file_system/file_system.dart';
import 'package:analyzer/src/context/builder.dart';
import 'package:analyzer/src/dart/ast/ast.dart';
import 'package:analyzer/src/dart/ast/ast_factory.dart';
import 'package:analyzer/src/dart/ast/token.dart';
import 'package:analyzer/src/dart/ast/utilities.dart';
import 'package:analyzer/src/dart/element/element.dart';
import 'package:analyzer/src/dart/element/inheritance_manager2.dart';
import 'package:analyzer/src/dart/element/member.dart' show ConstructorMember;
import 'package:analyzer/src/dart/element/type.dart';
import 'package:analyzer/src/dart/resolver/exit_detector.dart';
import 'package:analyzer/src/dart/resolver/scope.dart';
import 'package:analyzer/src/error/codes.dart';
import 'package:analyzer/src/generated/constant.dart';
import 'package:analyzer/src/generated/element_resolver.dart';
import 'package:analyzer/src/generated/engine.dart';
import 'package:analyzer/src/generated/source.dart';
import 'package:analyzer/src/generated/static_type_analyzer.dart';
import 'package:analyzer/src/generated/testing/element_factory.dart';
import 'package:analyzer/src/generated/type_system.dart';
import 'package:analyzer/src/lint/linter.dart';
import 'package:analyzer/src/workspace/workspace.dart';
import 'package:meta/meta.dart';
import 'package:path/path.dart' as path;
export 'package:analyzer/src/dart/constant/constant_verifier.dart';
export 'package:analyzer/src/dart/resolver/exit_detector.dart';
export 'package:analyzer/src/dart/resolver/inheritance_manager.dart';
export 'package:analyzer/src/dart/resolver/scope.dart';
export 'package:analyzer/src/generated/type_system.dart';
/// A visitor that will re-write an AST to support the optional `new` and
/// `const` feature.
class AstRewriteVisitor extends ScopedVisitor {
final bool addConstKeyword;
final TypeSystem typeSystem;
/// Initialize a newly created visitor.
AstRewriteVisitor(
this.typeSystem,
LibraryElement definingLibrary,
Source source,
TypeProvider typeProvider,
AnalysisErrorListener errorListener,
{Scope nameScope,
this.addConstKeyword: false})
: super(definingLibrary, source, typeProvider, errorListener,
nameScope: nameScope);
@override
void visitMethodInvocation(MethodInvocation node) {
super.visitMethodInvocation(node);
SimpleIdentifier methodName = node.methodName;
if (methodName.isSynthetic) {
// This isn't a constructor invocation because the method name is
// synthetic.
return;
}
Expression target = node.target;
if (target == null) {
// Possible cases: C() or C<>()
if (node.realTarget != null) {
// This isn't a constructor invocation because it's in a cascade.
return;
}
Element element = nameScope.lookup(methodName, definingLibrary);
if (element is ClassElement) {
AstFactory astFactory = new AstFactoryImpl();
TypeName typeName = astFactory.typeName(methodName, node.typeArguments);
ConstructorName constructorName =
astFactory.constructorName(typeName, null, null);
InstanceCreationExpression instanceCreationExpression =
astFactory.instanceCreationExpression(
_getKeyword(node), constructorName, node.argumentList);
InterfaceType type = getType(typeSystem, element, node.typeArguments);
ConstructorElement constructorElement =
type.lookUpConstructor(null, definingLibrary);
methodName.staticElement = element;
methodName.staticType = type;
typeName.type = type;
constructorName.staticElement = constructorElement;
instanceCreationExpression.staticType = type;
instanceCreationExpression.staticElement = constructorElement;
NodeReplacer.replace(node, instanceCreationExpression);
}
} else if (target is SimpleIdentifier) {
// Possible cases: C.n(), p.C() or p.C<>()
if (node.operator.type == TokenType.QUESTION_PERIOD) {
// This isn't a constructor invocation because a null aware operator is
// being used.
}
Element element = nameScope.lookup(target, definingLibrary);
if (element is ClassElement) {
// Possible case: C.n()
var constructorElement = element.getNamedConstructor(methodName.name);
if (constructorElement != null) {
var typeArguments = node.typeArguments;
if (typeArguments != null) {
errorReporter.reportErrorForNode(
StaticTypeWarningCode
.WRONG_NUMBER_OF_TYPE_ARGUMENTS_CONSTRUCTOR,
typeArguments,
[element.name, constructorElement.name]);
}
AstFactory astFactory = new AstFactoryImpl();
TypeName typeName = astFactory.typeName(target, null);
ConstructorName constructorName =
astFactory.constructorName(typeName, node.operator, methodName);
InstanceCreationExpression instanceCreationExpression =
astFactory.instanceCreationExpression(
_getKeyword(node), constructorName, node.argumentList,
typeArguments: typeArguments);
InterfaceType type = getType(typeSystem, element, null);
constructorElement =
type.lookUpConstructor(methodName.name, definingLibrary);
methodName.staticElement = element;
methodName.staticType = type;
target.staticElement = element;
target.staticType = type; // TODO(scheglov) remove this
typeName.type = type;
constructorName.staticElement = constructorElement;
instanceCreationExpression.staticType = type;
instanceCreationExpression.staticElement = constructorElement;
NodeReplacer.replace(node, instanceCreationExpression);
}
} else if (element is PrefixElement) {
// Possible cases: p.C() or p.C<>()
AstFactory astFactory = new AstFactoryImpl();
Identifier identifier = astFactory.prefixedIdentifier(
astFactory.simpleIdentifier(target.token),
null,
astFactory.simpleIdentifier(methodName.token));
Element prefixedElement = nameScope.lookup(identifier, definingLibrary);
if (prefixedElement is ClassElement) {
TypeName typeName = astFactory.typeName(
astFactory.prefixedIdentifier(target, node.operator, methodName),
node.typeArguments);
ConstructorName constructorName =
astFactory.constructorName(typeName, null, null);
InstanceCreationExpression instanceCreationExpression =
astFactory.instanceCreationExpression(
_getKeyword(node), constructorName, node.argumentList);
InterfaceType type =
getType(typeSystem, prefixedElement, node.typeArguments);
ConstructorElement constructorElement =
type.lookUpConstructor(null, definingLibrary);
methodName.staticElement = element;
methodName.staticType = type;
typeName.type = type;
constructorName.staticElement = constructorElement;
instanceCreationExpression.staticType = type;
instanceCreationExpression.staticElement = constructorElement;
NodeReplacer.replace(node, instanceCreationExpression);
}
}
} else if (target is PrefixedIdentifier) {
// Possible case: p.C.n()
Element prefixElement = nameScope.lookup(target.prefix, definingLibrary);
target.prefix.staticElement = prefixElement;
if (prefixElement is PrefixElement) {
Element element = nameScope.lookup(target, definingLibrary);
if (element is ClassElement) {
var constructorElement = element.getNamedConstructor(methodName.name);
if (constructorElement != null) {
var typeArguments = node.typeArguments;
if (typeArguments != null) {
errorReporter.reportErrorForNode(
StaticTypeWarningCode
.WRONG_NUMBER_OF_TYPE_ARGUMENTS_CONSTRUCTOR,
typeArguments,
[element.name, constructorElement.name]);
}
AstFactory astFactory = new AstFactoryImpl();
TypeName typeName = astFactory.typeName(target, typeArguments);
ConstructorName constructorName =
astFactory.constructorName(typeName, node.operator, methodName);
InstanceCreationExpression instanceCreationExpression =
astFactory.instanceCreationExpression(
_getKeyword(node), constructorName, node.argumentList);
InterfaceType type = getType(typeSystem, element, typeArguments);
constructorElement =
type.lookUpConstructor(methodName.name, definingLibrary);
methodName.staticElement = element;
methodName.staticType = type;
target.identifier.staticElement = element;
typeName.type = type;
constructorName.staticElement = constructorElement;
instanceCreationExpression.staticType = type;
instanceCreationExpression.staticElement = constructorElement;
NodeReplacer.replace(node, instanceCreationExpression);
}
}
}
}
}
/// Return the token that should be used in the [InstanceCreationExpression]
/// that corresponds to the given invocation [node].
Token _getKeyword(MethodInvocation node) {
return addConstKeyword
? new KeywordToken(Keyword.CONST, node.offset)
: null;
}
/// Return the type of the given class [element] after substituting any type
/// arguments from the list of [typeArguments] for the class' type parameters.
static InterfaceType getType(TypeSystem typeSystem, ClassElement element,
TypeArgumentList typeArguments) {
DartType type = element.type;
List<TypeParameterElement> typeParameters = element.typeParameters;
if (typeParameters.isEmpty) {
return type;
}
if (typeArguments == null) {
return typeSystem.instantiateToBounds(type);
}
List<DartType> argumentTypes;
if (typeArguments.arguments.length == typeParameters.length) {
argumentTypes = typeArguments.arguments
.map((TypeAnnotation argument) => argument.type)
.toList();
} else {
argumentTypes = List<DartType>.filled(
typeParameters.length, DynamicTypeImpl.instance);
}
List<DartType> parameterTypes = typeParameters
.map((TypeParameterElement parameter) => parameter.type)
.toList();
return type.substitute2(argumentTypes, parameterTypes);
}
}
/// Instances of the class `BestPracticesVerifier` traverse an AST structure
/// looking for violations of Dart best practices.
class BestPracticesVerifier extends RecursiveAstVisitor<void> {
// static String _HASHCODE_GETTER_NAME = "hashCode";
static String _NULL_TYPE_NAME = "Null";
static String _TO_INT_METHOD_NAME = "toInt";
/// The class containing the AST nodes being visited, or `null` if we are not
/// in the scope of a class.
ClassElementImpl _enclosingClass;
/// A flag indicating whether a surrounding member (compilation unit or class)
/// is deprecated.
bool _inDeprecatedMember;
/// The error reporter by which errors will be reported.
final ErrorReporter _errorReporter;
/// The type [Null].
final InterfaceType _nullType;
/// The type Future<Null>, which is needed for determining whether it is safe
/// to have a bare "return;" in an async method.
final InterfaceType _futureNullType;
/// The type system primitives
final TypeSystem _typeSystem;
/// The current library
final LibraryElement _currentLibrary;
final _InvalidAccessVerifier _invalidAccessVerifier;
/// The [WorkspacePackage] in which [_currentLibrary] is declared.
WorkspacePackage _workspacePackage;
/// The [LinterContext] used for possible const calculations.
LinterContext _linterContext;
/// Create a new instance of the [BestPracticesVerifier].
///
/// @param errorReporter the error reporter
BestPracticesVerifier(
this._errorReporter,
TypeProvider typeProvider,
this._currentLibrary, {
TypeSystem typeSystem,
ResourceProvider resourceProvider,
DeclaredVariables declaredVariables,
AnalysisOptions analysisOptions,
}) : _nullType = typeProvider.nullType,
_futureNullType = typeProvider.futureNullType,
_typeSystem = typeSystem ?? new Dart2TypeSystem(typeProvider),
_invalidAccessVerifier =
new _InvalidAccessVerifier(_errorReporter, _currentLibrary) {
_inDeprecatedMember = _currentLibrary.hasDeprecated;
String libraryPath = _currentLibrary.source.fullName;
ContextBuilder builder = new ContextBuilder(
resourceProvider, null /* sdkManager */, null /* contentCache */);
Workspace workspace =
ContextBuilder.createWorkspace(resourceProvider, libraryPath, builder);
_workspacePackage = workspace.findPackageFor(libraryPath);
_linterContext = LinterContextImpl(
null /* allUnits */,
null /* currentUnit */,
declaredVariables,
typeProvider,
_typeSystem,
analysisOptions);
}
@override
void visitAnnotation(Annotation node) {
ElementAnnotation element =
resolutionMap.elementAnnotationForAnnotation(node);
AstNode parent = node.parent;
if (element?.isFactory == true) {
if (parent is MethodDeclaration) {
_checkForInvalidFactory(parent);
} else {
_errorReporter
.reportErrorForNode(HintCode.INVALID_FACTORY_ANNOTATION, node, []);
}
} else if (element?.isImmutable == true) {
if (parent is! ClassOrMixinDeclaration && parent is! ClassTypeAlias) {
_errorReporter.reportErrorForNode(
HintCode.INVALID_IMMUTABLE_ANNOTATION, node, []);
}
} else if (element?.isLiteral == true) {
if (parent is! ConstructorDeclaration ||
(parent as ConstructorDeclaration).constKeyword == null) {
_errorReporter
.reportErrorForNode(HintCode.INVALID_LITERAL_ANNOTATION, node, []);
}
} else if (element?.isSealed == true) {
if (!(parent is ClassDeclaration || parent is ClassTypeAlias)) {
_errorReporter.reportErrorForNode(
HintCode.INVALID_SEALED_ANNOTATION, node, [node.element.name]);
}
} else if (element?.isVisibleForTemplate == true ||
element?.isVisibleForTesting == true) {
if (parent is Declaration) {
reportInvalidAnnotation(Element declaredElement) {
_errorReporter.reportErrorForNode(
HintCode.INVALID_VISIBILITY_ANNOTATION,
node,
[declaredElement.name, node.name.name]);
}
if (parent is TopLevelVariableDeclaration) {
for (VariableDeclaration variable in parent.variables.variables) {
if (Identifier.isPrivateName(variable.declaredElement.name)) {
reportInvalidAnnotation(variable.declaredElement);
}
}
} else if (parent is FieldDeclaration) {
for (VariableDeclaration variable in parent.fields.variables) {
if (Identifier.isPrivateName(variable.declaredElement.name)) {
reportInvalidAnnotation(variable.declaredElement);
}
}
} else if (parent.declaredElement != null &&
Identifier.isPrivateName(parent.declaredElement.name)) {
reportInvalidAnnotation(parent.declaredElement);
}
} else {
// Something other than a declaration was annotated. Whatever this is,
// it probably warrants a Hint, but this has not been specified on
// visibleForTemplate or visibleForTesting, so leave it alone for now.
}
}
super.visitAnnotation(node);
}
@override
void visitArgumentList(ArgumentList node) {
for (Expression argument in node.arguments) {
ParameterElement parameter = argument.staticParameterElement;
if (parameter?.isOptionalPositional == true) {
_checkForDeprecatedMemberUse(parameter, argument);
}
}
super.visitArgumentList(node);
}
@override
void visitAsExpression(AsExpression node) {
_checkForUnnecessaryCast(node);
super.visitAsExpression(node);
}
@override
void visitAssignmentExpression(AssignmentExpression node) {
TokenType operatorType = node.operator.type;
if (operatorType != TokenType.EQ) {
_checkForDeprecatedMemberUse(node.staticElement, node);
}
super.visitAssignmentExpression(node);
}
@override
void visitBinaryExpression(BinaryExpression node) {
_checkForDivisionOptimizationHint(node);
_checkForDeprecatedMemberUse(node.staticElement, node);
super.visitBinaryExpression(node);
}
@override
void visitClassDeclaration(ClassDeclaration node) {
var element = AbstractClassElementImpl.getImpl(node.declaredElement);
_enclosingClass = element;
_invalidAccessVerifier._enclosingClass = element;
bool wasInDeprecatedMember = _inDeprecatedMember;
if (element != null && element.hasDeprecated) {
_inDeprecatedMember = true;
}
try {
// Commented out until we decide that we want this hint in the analyzer
// checkForOverrideEqualsButNotHashCode(node);
_checkForImmutable(node);
_checkForInvalidSealedSuperclass(node);
super.visitClassDeclaration(node);
} finally {
_enclosingClass = null;
_invalidAccessVerifier._enclosingClass = null;
_inDeprecatedMember = wasInDeprecatedMember;
}
}
@override
void visitClassTypeAlias(ClassTypeAlias node) {
_checkForImmutable(node);
_checkForInvalidSealedSuperclass(node);
super.visitClassTypeAlias(node);
}
@override
void visitConstructorDeclaration(ConstructorDeclaration node) {
if (resolutionMap.elementDeclaredByConstructorDeclaration(node).isFactory) {
if (node.body is BlockFunctionBody) {
// Check the block for a return statement, if not, create the hint.
if (!ExitDetector.exits(node.body)) {
_errorReporter.reportErrorForNode(
HintCode.MISSING_RETURN, node, [node.returnType.name]);
}
}
}
super.visitConstructorDeclaration(node);
}
@override
void visitExportDirective(ExportDirective node) {
_checkForDeprecatedMemberUse(node.uriElement, node);
super.visitExportDirective(node);
}
@override
void visitFieldDeclaration(FieldDeclaration node) {
bool wasInDeprecatedMember = _inDeprecatedMember;
if (_hasDeprecatedAnnotation(node.metadata)) {
_inDeprecatedMember = true;
}
try {
super.visitFieldDeclaration(node);
} finally {
_inDeprecatedMember = wasInDeprecatedMember;
}
}
@override
void visitFormalParameterList(FormalParameterList node) {
_checkRequiredParameter(node);
super.visitFormalParameterList(node);
}
@override
void visitFunctionDeclaration(FunctionDeclaration node) {
bool wasInDeprecatedMember = _inDeprecatedMember;
ExecutableElement element = node.declaredElement;
if (element != null && element.hasDeprecated) {
_inDeprecatedMember = true;
}
try {
_checkForMissingReturn(
node.returnType, node.functionExpression.body, element, node);
super.visitFunctionDeclaration(node);
} finally {
_inDeprecatedMember = wasInDeprecatedMember;
}
}
@override
void visitImportDirective(ImportDirective node) {
_checkForDeprecatedMemberUse(node.uriElement, node);
ImportElement importElement = node.element;
if (importElement != null && importElement.isDeferred) {
_checkForLoadLibraryFunction(node, importElement);
}
super.visitImportDirective(node);
}
@override
void visitIndexExpression(IndexExpression node) {
_checkForDeprecatedMemberUse(node.staticElement, node);
super.visitIndexExpression(node);
}
@override
void visitInstanceCreationExpression(InstanceCreationExpression node) {
_checkForDeprecatedMemberUse(node.staticElement, node);
_checkForLiteralConstructorUse(node);
super.visitInstanceCreationExpression(node);
}
@override
void visitIsExpression(IsExpression node) {
_checkAllTypeChecks(node);
super.visitIsExpression(node);
}
@override
void visitMethodDeclaration(MethodDeclaration node) {
bool wasInDeprecatedMember = _inDeprecatedMember;
ExecutableElement element = node.declaredElement;
if (element != null && element.hasDeprecated) {
_inDeprecatedMember = true;
}
try {
// This was determined to not be a good hint, see: dartbug.com/16029
//checkForOverridingPrivateMember(node);
_checkForMissingReturn(node.returnType, node.body, element, node);
_checkForUnnecessaryNoSuchMethod(node);
super.visitMethodDeclaration(node);
} finally {
_inDeprecatedMember = wasInDeprecatedMember;
}
}
@override
void visitMethodInvocation(MethodInvocation node) {
_checkForNullAwareHints(node, node.operator);
DartType staticInvokeType = node.staticInvokeType;
Element callElement = staticInvokeType?.element;
if (callElement is MethodElement &&
callElement.name == FunctionElement.CALL_METHOD_NAME) {
_checkForDeprecatedMemberUse(callElement, node);
}
super.visitMethodInvocation(node);
}
@override
void visitMixinDeclaration(MixinDeclaration node) {
_enclosingClass = node.declaredElement;
_invalidAccessVerifier._enclosingClass = _enclosingClass;
bool wasInDeprecatedMember = _inDeprecatedMember;
if (_hasDeprecatedAnnotation(node.metadata)) {
_inDeprecatedMember = true;
}
try {
_checkForImmutable(node);
_checkForInvalidSealedSuperclass(node);
super.visitMixinDeclaration(node);
} finally {
_enclosingClass = null;
_invalidAccessVerifier._enclosingClass = null;
_inDeprecatedMember = wasInDeprecatedMember;
}
}
@override
void visitPostfixExpression(PostfixExpression node) {
_checkForDeprecatedMemberUse(node.staticElement, node);
super.visitPostfixExpression(node);
}
@override
void visitPrefixExpression(PrefixExpression node) {
_checkForDeprecatedMemberUse(node.staticElement, node);
super.visitPrefixExpression(node);
}
@override
void visitPropertyAccess(PropertyAccess node) {
_checkForNullAwareHints(node, node.operator);
super.visitPropertyAccess(node);
}
@override
void visitRedirectingConstructorInvocation(
RedirectingConstructorInvocation node) {
_checkForDeprecatedMemberUse(node.staticElement, node);
super.visitRedirectingConstructorInvocation(node);
}
@override
void visitSimpleIdentifier(SimpleIdentifier node) {
_checkForDeprecatedMemberUseAtIdentifier(node);
_invalidAccessVerifier.verify(node);
super.visitSimpleIdentifier(node);
}
@override
void visitSuperConstructorInvocation(SuperConstructorInvocation node) {
_checkForDeprecatedMemberUse(node.staticElement, node);
super.visitSuperConstructorInvocation(node);
}
@override
void visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
bool wasInDeprecatedMember = _inDeprecatedMember;
if (_hasDeprecatedAnnotation(node.metadata)) {
_inDeprecatedMember = true;
}
try {
super.visitTopLevelVariableDeclaration(node);
} finally {
_inDeprecatedMember = wasInDeprecatedMember;
}
}
/// Check for the passed is expression for the unnecessary type check hint
/// codes as well as null checks expressed using an is expression.
///
/// @param node the is expression to check
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.TYPE_CHECK_IS_NOT_NULL], [HintCode.TYPE_CHECK_IS_NULL],
/// [HintCode.UNNECESSARY_TYPE_CHECK_TRUE], and
/// [HintCode.UNNECESSARY_TYPE_CHECK_FALSE].
bool _checkAllTypeChecks(IsExpression node) {
Expression expression = node.expression;
TypeAnnotation typeName = node.type;
DartType lhsType = expression.staticType;
DartType rhsType = typeName.type;
if (lhsType == null || rhsType == null) {
return false;
}
String rhsNameStr = typeName is TypeName ? typeName.name.name : null;
// if x is dynamic
if (rhsType.isDynamic && rhsNameStr == Keyword.DYNAMIC.lexeme) {
if (node.notOperator == null) {
// the is case
_errorReporter.reportErrorForNode(
HintCode.UNNECESSARY_TYPE_CHECK_TRUE, node);
} else {
// the is not case
_errorReporter.reportErrorForNode(
HintCode.UNNECESSARY_TYPE_CHECK_FALSE, node);
}
return true;
}
Element rhsElement = rhsType.element;
LibraryElement libraryElement = rhsElement?.library;
if (libraryElement != null && libraryElement.isDartCore) {
// if x is Object or null is Null
if (rhsType.isObject ||
(expression is NullLiteral && rhsNameStr == _NULL_TYPE_NAME)) {
if (node.notOperator == null) {
// the is case
_errorReporter.reportErrorForNode(
HintCode.UNNECESSARY_TYPE_CHECK_TRUE, node);
} else {
// the is not case
_errorReporter.reportErrorForNode(
HintCode.UNNECESSARY_TYPE_CHECK_FALSE, node);
}
return true;
} else if (rhsNameStr == _NULL_TYPE_NAME) {
if (node.notOperator == null) {
// the is case
_errorReporter.reportErrorForNode(HintCode.TYPE_CHECK_IS_NULL, node);
} else {
// the is not case
_errorReporter.reportErrorForNode(
HintCode.TYPE_CHECK_IS_NOT_NULL, node);
}
return true;
}
}
return false;
}
/// Given some [Element], look at the associated metadata and report the use
/// of the member if it is declared as deprecated.
///
/// @param element some element to check for deprecated use of
/// @param node the node use for the location of the error
/// See [HintCode.DEPRECATED_MEMBER_USE].
void _checkForDeprecatedMemberUse(Element element, AstNode node) {
bool isDeprecated(Element element) {
if (element is PropertyAccessorElement && element.isSynthetic) {
// TODO(brianwilkerson) Why isn't this the implementation for PropertyAccessorElement?
Element variable = element.variable;
if (variable == null) {
return false;
}
return variable.hasDeprecated;
}
return element.hasDeprecated;
}
bool isLocalParameter(Element element, AstNode node) {
if (element is ParameterElement) {
ExecutableElement definingFunction = element.enclosingElement;
FunctionBody body = node.thisOrAncestorOfType<FunctionBody>();
while (body != null) {
ExecutableElement enclosingFunction;
AstNode parent = body.parent;
if (parent is ConstructorDeclaration) {
enclosingFunction = parent.declaredElement;
} else if (parent is FunctionExpression) {
enclosingFunction = parent.declaredElement;
} else if (parent is MethodDeclaration) {
enclosingFunction = parent.declaredElement;
}
if (enclosingFunction == definingFunction) {
return true;
}
body = parent?.thisOrAncestorOfType<FunctionBody>();
}
}
return false;
}
bool isLibraryInWorkspacePackage(LibraryElement library) {
if (_workspacePackage == null || library == null) {
// Better to not make a big claim that they _are_ in the same package,
// if we were unable to determine what package [_currentLibrary] is in.
return false;
}
return _workspacePackage.contains(library.source.fullName);
}
if (!_inDeprecatedMember &&
element != null &&
isDeprecated(element) &&
!isLocalParameter(element, node)) {
String displayName = element.displayName;
if (element is ConstructorElement) {
// TODO(jwren) We should modify ConstructorElement.getDisplayName(),
// or have the logic centralized elsewhere, instead of doing this logic
// here.
displayName = element.enclosingElement.displayName;
if (!element.displayName.isEmpty) {
displayName = "$displayName.${element.displayName}";
}
} else if (element is LibraryElement) {
displayName = element.definingCompilationUnit.source.uri.toString();
} else if (displayName == FunctionElement.CALL_METHOD_NAME &&
node is MethodInvocation &&
node.staticInvokeType is InterfaceType) {
DartType staticInvokeType =
resolutionMap.staticInvokeTypeForInvocationExpression(node);
displayName = "${staticInvokeType.displayName}.${element.displayName}";
}
LibraryElement library =
element is LibraryElement ? element : element.library;
HintCode hintCode = isLibraryInWorkspacePackage(library)
? HintCode.DEPRECATED_MEMBER_USE_FROM_SAME_PACKAGE
: HintCode.DEPRECATED_MEMBER_USE;
_errorReporter.reportErrorForNode(hintCode, node, [displayName]);
}
}
/// For [SimpleIdentifier]s, only call [checkForDeprecatedMemberUse]
/// if the node is not in a declaration context.
///
/// Also, if the identifier is a constructor name in a constructor invocation,
/// then calls to the deprecated constructor will be caught by
/// [visitInstanceCreationExpression] and
/// [visitSuperConstructorInvocation], and can be ignored by
/// this visit method.
///
/// @param identifier some simple identifier to check for deprecated use of
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.DEPRECATED_MEMBER_USE].
void _checkForDeprecatedMemberUseAtIdentifier(SimpleIdentifier identifier) {
if (identifier.inDeclarationContext()) {
return;
}
AstNode parent = identifier.parent;
if ((parent is ConstructorName && identical(identifier, parent.name)) ||
(parent is ConstructorDeclaration &&
identical(identifier, parent.returnType)) ||
(parent is SuperConstructorInvocation &&
identical(identifier, parent.constructorName)) ||
parent is HideCombinator) {
return;
}
_checkForDeprecatedMemberUse(identifier.staticElement, identifier);
}
/// Check for the passed binary expression for the
/// [HintCode.DIVISION_OPTIMIZATION].
///
/// @param node the binary expression to check
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.DIVISION_OPTIMIZATION].
bool _checkForDivisionOptimizationHint(BinaryExpression node) {
// Return if the operator is not '/'
if (node.operator.type != TokenType.SLASH) {
return false;
}
// Return if the '/' operator is not defined in core, or if we don't know
// its static type
MethodElement methodElement = node.staticElement;
if (methodElement == null) {
return false;
}
LibraryElement libraryElement = methodElement.library;
if (libraryElement != null && !libraryElement.isDartCore) {
return false;
}
// Report error if the (x/y) has toInt() invoked on it
AstNode parent = node.parent;
if (parent is ParenthesizedExpression) {
ParenthesizedExpression parenthesizedExpression =
_wrapParenthesizedExpression(parent);
AstNode grandParent = parenthesizedExpression.parent;
if (grandParent is MethodInvocation) {
if (_TO_INT_METHOD_NAME == grandParent.methodName.name &&
grandParent.argumentList.arguments.isEmpty) {
_errorReporter.reportErrorForNode(
HintCode.DIVISION_OPTIMIZATION, grandParent);
return true;
}
}
}
return false;
}
/// Checks whether [node] violates the rules of [immutable].
///
/// If [node] is marked with [immutable] or inherits from a class or mixin
/// marked with [immutable], this function searches the fields of [node] and
/// its superclasses, reporting a hint if any non-final instance fields are
/// found.
void _checkForImmutable(NamedCompilationUnitMember node) {
/// Return `true` if the given class [element] is annotated with the
/// `@immutable` annotation.
bool isImmutable(ClassElement element) {
for (ElementAnnotation annotation in element.metadata) {
if (annotation.isImmutable) {
return true;
}
}
return false;
}
/// Return `true` if the given class [element] or any superclass of it is
/// annotated with the `@immutable` annotation.
bool isOrInheritsImmutable(
ClassElement element, HashSet<ClassElement> visited) {
if (visited.add(element)) {
if (isImmutable(element)) {
return true;
}
for (InterfaceType interface in element.mixins) {
if (isOrInheritsImmutable(interface.element, visited)) {
return true;
}
}
for (InterfaceType mixin in element.interfaces) {
if (isOrInheritsImmutable(mixin.element, visited)) {
return true;
}
}
if (element.supertype != null) {
return isOrInheritsImmutable(element.supertype.element, visited);
}
}
return false;
}
/// Return `true` if the given class [element] defines a non-final instance
/// field.
Iterable<String> nonFinalInstanceFields(ClassElement element) {
return element.fields
.where((FieldElement field) =>
!field.isSynthetic && !field.isFinal && !field.isStatic)
.map((FieldElement field) => '${element.name}.${field.name}');
}
/// Return `true` if the given class [element] defines or inherits a
/// non-final field.
Iterable<String> definedOrInheritedNonFinalInstanceFields(
ClassElement element, HashSet<ClassElement> visited) {
Iterable<String> nonFinalFields = [];
if (visited.add(element)) {
nonFinalFields = nonFinalInstanceFields(element);
nonFinalFields = nonFinalFields.followedBy(element.mixins.expand(
(InterfaceType mixin) => nonFinalInstanceFields(mixin.element)));
if (element.supertype != null) {
nonFinalFields = nonFinalFields.followedBy(
definedOrInheritedNonFinalInstanceFields(
element.supertype.element, visited));
}
}
return nonFinalFields;
}
ClassElement element = node.declaredElement;
if (isOrInheritsImmutable(element, new HashSet<ClassElement>())) {
Iterable<String> nonFinalFields =
definedOrInheritedNonFinalInstanceFields(
element, new HashSet<ClassElement>());
if (nonFinalFields.isNotEmpty) {
_errorReporter.reportErrorForNode(
HintCode.MUST_BE_IMMUTABLE, node.name, [nonFinalFields.join(', ')]);
}
}
}
void _checkForInvalidFactory(MethodDeclaration decl) {
// Check declaration.
// Note that null return types are expected to be flagged by other analyses.
DartType returnType = decl.returnType?.type;
if (returnType is VoidType) {
_errorReporter.reportErrorForNode(HintCode.INVALID_FACTORY_METHOD_DECL,
decl.name, [decl.name.toString()]);
return;
}
// Check implementation.
FunctionBody body = decl.body;
if (body is EmptyFunctionBody) {
// Abstract methods are OK.
return;
}
// `new Foo()` or `null`.
bool factoryExpression(Expression expression) =>
expression is InstanceCreationExpression || expression is NullLiteral;
if (body is ExpressionFunctionBody && factoryExpression(body.expression)) {
return;
} else if (body is BlockFunctionBody) {
NodeList<Statement> statements = body.block.statements;
if (statements.isNotEmpty) {
Statement last = statements.last;
if (last is ReturnStatement && factoryExpression(last.expression)) {
return;
}
}
}
_errorReporter.reportErrorForNode(HintCode.INVALID_FACTORY_METHOD_IMPL,
decl.name, [decl.name.toString()]);
}
void _checkForInvalidSealedSuperclass(NamedCompilationUnitMember node) {
bool currentPackageContains(Element element) {
String elementLibraryPath = element.library.source.fullName;
return _workspacePackage.contains(elementLibraryPath);
}
// [NamedCompilationUnitMember.declaredElement] is not necessarily a
// ClassElement, but [_checkForInvalidSealedSuperclass] should only be
// called with a [ClassOrMixinDeclaration], or a [ClassTypeAlias]. The
// `declaredElement` of these specific classes is a [ClassElement].
ClassElement element = node.declaredElement;
// TODO(srawlins): Perhaps replace this with a getter on Element, like
// `Element.hasOrInheritsSealed`?
for (InterfaceType supertype in element.allSupertypes) {
ClassElement superclass = supertype.element;
if (superclass.hasSealed) {
if (!currentPackageContains(superclass)) {
if (element.superclassConstraints.contains(supertype)) {
// This is a special violation of the sealed class contract,
// requiring specific messaging.
_errorReporter.reportErrorForNode(HintCode.MIXIN_ON_SEALED_CLASS,
node, [superclass.name.toString()]);
} else {
// This is a regular violation of the sealed class contract.
_errorReporter.reportErrorForNode(HintCode.SUBTYPE_OF_SEALED_CLASS,
node, [superclass.name.toString()]);
}
}
}
}
}
/// Check that the instance creation node is const if the constructor is
/// marked with [literal].
_checkForLiteralConstructorUse(InstanceCreationExpression node) {
ConstructorName constructorName = node.constructorName;
ConstructorElement constructor = constructorName.staticElement;
if (constructor == null) {
return;
}
if (!node.isConst &&
constructor.hasLiteral &&
_linterContext.canBeConst(node)) {
// Echoing jwren's TODO from _checkForDeprecatedMemberUse:
// TODO(jwren) We should modify ConstructorElement.getDisplayName(), or
// have the logic centralized elsewhere, instead of doing this logic
// here.
String fullConstructorName = constructorName.type.name.name;
if (constructorName.name != null) {
fullConstructorName = '$fullConstructorName.${constructorName.name}';
}
HintCode hint = node.keyword?.keyword == Keyword.NEW
? HintCode.NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR_USING_NEW
: HintCode.NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR;
_errorReporter.reportErrorForNode(hint, node, [fullConstructorName]);
}
}
/// Check that the imported library does not define a loadLibrary function.
/// The import has already been determined to be deferred when this is called.
///
/// @param node the import directive to evaluate
/// @param importElement the [ImportElement] retrieved from the node
/// @return `true` if and only if an error code is generated on the passed
/// node
/// See [CompileTimeErrorCode.IMPORT_DEFERRED_LIBRARY_WITH_LOAD_FUNCTION].
bool _checkForLoadLibraryFunction(
ImportDirective node, ImportElement importElement) {
LibraryElement importedLibrary = importElement.importedLibrary;
if (importedLibrary == null) {
return false;
}
if (importedLibrary.hasLoadLibraryFunction) {
_errorReporter.reportErrorForNode(
HintCode.IMPORT_DEFERRED_LIBRARY_WITH_LOAD_FUNCTION,
node,
[importedLibrary.name]);
return true;
}
return false;
}
/// Generate a hint for functions or methods that have a return type, but do
/// not have a return statement on all branches. At the end of blocks with no
/// return, Dart implicitly returns `null`, avoiding these implicit returns is
/// considered a best practice.
///
/// Note: for async functions/methods, this hint only applies when the
/// function has a return type that Future<Null> is not assignable to.
///
/// @param node the binary expression to check
/// @param body the function body
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.MISSING_RETURN].
void _checkForMissingReturn(TypeAnnotation returnNode, FunctionBody body,
ExecutableElement element, AstNode functionNode) {
if (body is BlockFunctionBody) {
// Prefer the type from the element model, in case we've inferred one.
DartType returnType = element?.returnType ?? returnNode?.type;
AstNode errorNode = returnNode ?? functionNode;
// Skip the check if we're missing a return type (e.g. erroneous code).
// Generators are never required to have a return statement.
if (returnType == null || body.isGenerator) {
return;
}
var flattenedType =
body.isAsynchronous ? _typeSystem.flatten(returnType) : returnType;
// dynamic/Null/void are allowed to omit a return.
if (flattenedType.isDynamic ||
flattenedType.isDartCoreNull ||
flattenedType.isVoid) {
return;
}
// Otherwise issue a warning if the block doesn't have a return.
if (!ExitDetector.exits(body)) {
_errorReporter.reportErrorForNode(
HintCode.MISSING_RETURN, errorNode, [returnType.displayName]);
}
}
}
/// Produce several null-aware related hints.
void _checkForNullAwareHints(Expression node, Token operator) {
if (operator == null || operator.type != TokenType.QUESTION_PERIOD) {
return;
}
// childOfParent is used to know from which branch node comes.
var childOfParent = node;
var parent = node.parent;
while (parent is ParenthesizedExpression) {
childOfParent = parent;
parent = parent.parent;
}
// CAN_BE_NULL_AFTER_NULL_AWARE
if (parent is MethodInvocation &&
parent.operator.type != TokenType.QUESTION_PERIOD &&
_nullType.lookUpMethod(parent.methodName.name, _currentLibrary) ==
null) {
_errorReporter.reportErrorForNode(
HintCode.CAN_BE_NULL_AFTER_NULL_AWARE, childOfParent);
return;
}
if (parent is PropertyAccess &&
parent.operator.type != TokenType.QUESTION_PERIOD &&
_nullType.lookUpGetter(parent.propertyName.name, _currentLibrary) ==
null) {
_errorReporter.reportErrorForNode(
HintCode.CAN_BE_NULL_AFTER_NULL_AWARE, childOfParent);
return;
}
if (parent is CascadeExpression && parent.target == childOfParent) {
_errorReporter.reportErrorForNode(
HintCode.CAN_BE_NULL_AFTER_NULL_AWARE, childOfParent);
return;
}
// NULL_AWARE_IN_CONDITION
if (parent is IfStatement && parent.condition == childOfParent ||
parent is ForPartsWithDeclarations &&
parent.condition == childOfParent ||
parent is DoStatement && parent.condition == childOfParent ||
parent is WhileStatement && parent.condition == childOfParent ||
parent is ConditionalExpression && parent.condition == childOfParent ||
parent is AssertStatement && parent.condition == childOfParent) {
_errorReporter.reportErrorForNode(
HintCode.NULL_AWARE_IN_CONDITION, childOfParent);
return;
}
// NULL_AWARE_IN_LOGICAL_OPERATOR
if (parent is PrefixExpression && parent.operator.type == TokenType.BANG ||
parent is BinaryExpression &&
[TokenType.BAR_BAR, TokenType.AMPERSAND_AMPERSAND]
.contains(parent.operator.type)) {
_errorReporter.reportErrorForNode(
HintCode.NULL_AWARE_IN_LOGICAL_OPERATOR, childOfParent);
return;
}
// NULL_AWARE_BEFORE_OPERATOR
if (parent is BinaryExpression &&
![TokenType.EQ_EQ, TokenType.BANG_EQ, TokenType.QUESTION_QUESTION]
.contains(parent.operator.type) &&
parent.leftOperand == childOfParent) {
_errorReporter.reportErrorForNode(
HintCode.NULL_AWARE_BEFORE_OPERATOR, childOfParent);
return;
}
}
/// Check for the passed as expression for the [HintCode.UNNECESSARY_CAST]
/// hint code.
///
/// @param node the as expression to check
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.UNNECESSARY_CAST].
bool _checkForUnnecessaryCast(AsExpression node) {
// TODO(jwren) After dartbug.com/13732, revisit this, we should be able to
// remove the (x is! TypeParameterType) checks.
AstNode parent = node.parent;
if (parent is ConditionalExpression &&
(node == parent.thenExpression || node == parent.elseExpression)) {
Expression thenExpression = parent.thenExpression;
DartType thenType;
if (thenExpression is AsExpression) {
thenType = thenExpression.expression.staticType;
} else {
thenType = thenExpression.staticType;
}
Expression elseExpression = parent.elseExpression;
DartType elseType;
if (elseExpression is AsExpression) {
elseType = elseExpression.expression.staticType;
} else {
elseType = elseExpression.staticType;
}
if (thenType != null &&
elseType != null &&
!thenType.isDynamic &&
!elseType.isDynamic &&
!thenType.isMoreSpecificThan(elseType) &&
!elseType.isMoreSpecificThan(thenType)) {
return false;
}
}
DartType lhsType = node.expression.staticType;
DartType rhsType = node.type.type;
if (lhsType != null &&
rhsType != null &&
!lhsType.isDynamic &&
!rhsType.isDynamic &&
_typeSystem.isMoreSpecificThan(lhsType, rhsType)) {
_errorReporter.reportErrorForNode(HintCode.UNNECESSARY_CAST, node);
return true;
}
return false;
}
/// Generate a hint for `noSuchMethod` methods that do nothing except of
/// calling another `noSuchMethod` that is not defined by `Object`.
///
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.UNNECESSARY_NO_SUCH_METHOD].
bool _checkForUnnecessaryNoSuchMethod(MethodDeclaration node) {
if (node.name.name != FunctionElement.NO_SUCH_METHOD_METHOD_NAME) {
return false;
}
bool isNonObjectNoSuchMethodInvocation(Expression invocation) {
if (invocation is MethodInvocation &&
invocation.target is SuperExpression &&
invocation.argumentList.arguments.length == 1) {
SimpleIdentifier name = invocation.methodName;
if (name.name == FunctionElement.NO_SUCH_METHOD_METHOD_NAME) {
Element methodElement = name.staticElement;
Element classElement = methodElement?.enclosingElement;
return methodElement is MethodElement &&
classElement is ClassElement &&
!classElement.type.isObject;
}
}
return false;
}
FunctionBody body = node.body;
if (body is ExpressionFunctionBody) {
if (isNonObjectNoSuchMethodInvocation(body.expression)) {
_errorReporter.reportErrorForNode(
HintCode.UNNECESSARY_NO_SUCH_METHOD, node);
return true;
}
} else if (body is BlockFunctionBody) {
List<Statement> statements = body.block.statements;
if (statements.length == 1) {
Statement returnStatement = statements.first;
if (returnStatement is ReturnStatement &&
isNonObjectNoSuchMethodInvocation(returnStatement.expression)) {
_errorReporter.reportErrorForNode(
HintCode.UNNECESSARY_NO_SUCH_METHOD, node);
return true;
}
}
}
return false;
}
void _checkRequiredParameter(FormalParameterList node) {
final requiredParameters =
node.parameters.where((p) => p.declaredElement?.hasRequired == true);
final nonNamedParamsWithRequired =
requiredParameters.where((p) => !p.isNamed);
final namedParamsWithRequiredAndDefault = requiredParameters
.where((p) => p.isNamed)
.where((p) => p.declaredElement.defaultValueCode != null);
final paramsToHint = [
nonNamedParamsWithRequired,
namedParamsWithRequiredAndDefault
].expand((e) => e);
for (final param in paramsToHint) {
_errorReporter.reportErrorForNode(
HintCode.INVALID_REQUIRED_PARAM, param, [param.identifier.name]);
}
}
/// Check for the passed class declaration for the
/// [HintCode.OVERRIDE_EQUALS_BUT_NOT_HASH_CODE] hint code.
///
/// @param node the class declaration to check
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.OVERRIDE_EQUALS_BUT_NOT_HASH_CODE].
// bool _checkForOverrideEqualsButNotHashCode(ClassDeclaration node) {
// ClassElement classElement = node.element;
// if (classElement == null) {
// return false;
// }
// MethodElement equalsOperatorMethodElement =
// classElement.getMethod(sc.TokenType.EQ_EQ.lexeme);
// if (equalsOperatorMethodElement != null) {
// PropertyAccessorElement hashCodeElement =
// classElement.getGetter(_HASHCODE_GETTER_NAME);
// if (hashCodeElement == null) {
// _errorReporter.reportErrorForNode(
// HintCode.OVERRIDE_EQUALS_BUT_NOT_HASH_CODE,
// node.name,
// [classElement.displayName]);
// return true;
// }
// }
// return false;
// }
//
// /// Return `true` if the given [type] represents `Future<void>`.
// bool _isFutureVoid(DartType type) {
// if (type.isDartAsyncFuture) {
// List<DartType> typeArgs = (type as InterfaceType).typeArguments;
// if (typeArgs.length == 1 && typeArgs[0].isVoid) {
// return true;
// }
// }
// return false;
// }
static bool _hasDeprecatedAnnotation(List<Annotation> annotations) {
for (var i = 0; i < annotations.length; i++) {
if (annotations[i].elementAnnotation.isDeprecated) {
return true;
}
}
return false;
}
/// Given a parenthesized expression, this returns the parent (or recursively
/// grand-parent) of the expression that is a parenthesized expression, but
/// whose parent is not a parenthesized expression.
///
/// For example given the code `(((e)))`: `(e) -> (((e)))`.
///
/// @param parenthesizedExpression some expression whose parent is a
/// parenthesized expression
/// @return the first parent or grand-parent that is a parenthesized
/// expression, that does not have a parenthesized expression parent
static ParenthesizedExpression _wrapParenthesizedExpression(
ParenthesizedExpression parenthesizedExpression) {
AstNode parent = parenthesizedExpression.parent;
if (parent is ParenthesizedExpression) {
return _wrapParenthesizedExpression(parent);
}
return parenthesizedExpression;
}
}
/// Utilities for [LibraryElementImpl] building.
class BuildLibraryElementUtils {
/// Look through all of the compilation units defined for the given [library],
/// looking for getters and setters that are defined in different compilation
/// units but that have the same names. If any are found, make sure that they
/// have the same variable element.
static void patchTopLevelAccessors(LibraryElementImpl library) {
// Without parts getters/setters already share the same variable element.
List<CompilationUnitElement> parts = library.parts;
if (parts.isEmpty) {
return;
}
// Collect getters and setters.
Map<String, PropertyAccessorElement> getters =
new HashMap<String, PropertyAccessorElement>();
List<PropertyAccessorElement> setters = <PropertyAccessorElement>[];
_collectAccessors(getters, setters, library.definingCompilationUnit);
int partLength = parts.length;
for (int i = 0; i < partLength; i++) {
CompilationUnitElement unit = parts[i];
_collectAccessors(getters, setters, unit);
}
// Move every setter to the corresponding getter's variable (if exists).
int setterLength = setters.length;
for (int j = 0; j < setterLength; j++) {
PropertyAccessorElement setter = setters[j];
PropertyAccessorElement getter = getters[setter.displayName];
if (getter != null) {
TopLevelVariableElementImpl variable = getter.variable;
TopLevelVariableElementImpl setterVariable = setter.variable;
CompilationUnitElementImpl setterUnit = setterVariable.enclosingElement;
setterUnit.replaceTopLevelVariable(setterVariable, variable);
variable.setter = setter;
(setter as PropertyAccessorElementImpl).variable = variable;
}
}
}
/// Add all of the non-synthetic [getters] and [setters] defined in the given
/// [unit] that have no corresponding accessor to one of the given
/// collections.
static void _collectAccessors(Map<String, PropertyAccessorElement> getters,
List<PropertyAccessorElement> setters, CompilationUnitElement unit) {
List<PropertyAccessorElement> accessors = unit.accessors;
int length = accessors.length;
for (int i = 0; i < length; i++) {
PropertyAccessorElement accessor = accessors[i];
if (accessor.isGetter) {
if (!accessor.isSynthetic && accessor.correspondingSetter == null) {
getters[accessor.displayName] = accessor;
}
} else {
if (!accessor.isSynthetic && accessor.correspondingGetter == null) {
setters.add(accessor);
}
}
}
}
}
/// Instances of the class `Dart2JSVerifier` traverse an AST structure looking
/// for hints for code that will be compiled to JS, such as
/// [HintCode.IS_DOUBLE].
class Dart2JSVerifier extends RecursiveAstVisitor<void> {
/// The name of the `double` type.
static String _DOUBLE_TYPE_NAME = "double";
/// The error reporter by which errors will be reported.
final ErrorReporter _errorReporter;
/// Create a new instance of the [Dart2JSVerifier].
///
/// @param errorReporter the error reporter
Dart2JSVerifier(this._errorReporter);
@override
void visitIsExpression(IsExpression node) {
_checkForIsDoubleHints(node);
super.visitIsExpression(node);
}
/// Check for instances of `x is double`, `x is int`, `x is! double` and
/// `x is! int`.
///
/// @param node the is expression to check
/// @return `true` if and only if a hint code is generated on the passed node
/// See [HintCode.IS_DOUBLE],
/// [HintCode.IS_INT],
/// [HintCode.IS_NOT_DOUBLE], and
/// [HintCode.IS_NOT_INT].
bool _checkForIsDoubleHints(IsExpression node) {
DartType type = node.type.type;
Element element = type?.element;
if (element != null) {
String typeNameStr = element.name;
LibraryElement libraryElement = element.library;
// if (typeNameStr.equals(INT_TYPE_NAME) && libraryElement != null
// && libraryElement.isDartCore()) {
// if (node.getNotOperator() == null) {
// errorReporter.reportError(HintCode.IS_INT, node);
// } else {
// errorReporter.reportError(HintCode.IS_NOT_INT, node);
// }
// return true;
// } else
if (typeNameStr == _DOUBLE_TYPE_NAME &&
libraryElement != null &&
libraryElement.isDartCore) {
if (node.notOperator == null) {
_errorReporter.reportErrorForNode(HintCode.IS_DOUBLE, node);
} else {
_errorReporter.reportErrorForNode(HintCode.IS_NOT_DOUBLE, node);
}
return true;
}
}
return false;
}
}
/// A visitor that finds dead code and unused labels.
class DeadCodeVerifier extends RecursiveAstVisitor<void> {
/// The error reporter by which errors will be reported.
final ErrorReporter _errorReporter;
/// The type system for this visitor
final TypeSystem _typeSystem;
/// The object used to track the usage of labels within a given label scope.
_LabelTracker labelTracker;
/// Is `true` if this unit has been parsed as non-nullable.
final bool _isNonNullableUnit;
/// Initialize a newly created dead code verifier that will report dead code
/// to the given [errorReporter] and will use the given [typeSystem] if one is
/// provided.
DeadCodeVerifier(this._errorReporter, this._isNonNullableUnit,
{TypeSystem typeSystem})
: this._typeSystem = typeSystem ?? new Dart2TypeSystem(null);
@override
void visitAssignmentExpression(AssignmentExpression node) {
TokenType operatorType = node.operator.type;
if (operatorType == TokenType.QUESTION_QUESTION_EQ) {
_checkForDeadNullCoalesce(
node.leftHandSide.staticType, node.rightHandSide);
}
super.visitAssignmentExpression(node);
}
@override
void visitBinaryExpression(BinaryExpression node) {
Token operator = node.operator;
bool isAmpAmp = operator.type == TokenType.AMPERSAND_AMPERSAND;
bool isBarBar = operator.type == TokenType.BAR_BAR;
bool isQuestionQuestion = operator.type == TokenType.QUESTION_QUESTION;
if (isAmpAmp || isBarBar) {
Expression lhsCondition = node.leftOperand;
if (!_isDebugConstant(lhsCondition)) {
EvaluationResultImpl lhsResult = _getConstantBooleanValue(lhsCondition);
if (lhsResult != null) {
bool value = lhsResult.value.toBoolValue();
if (value == true && isBarBar) {
// Report error on "else" block: true || !e!
_errorReporter.reportErrorForNode(
HintCode.DEAD_CODE, node.rightOperand);
// Only visit the LHS:
lhsCondition?.accept(this);
return;
} else if (value == false && isAmpAmp) {
// Report error on "if" block: false && !e!
_errorReporter.reportErrorForNode(
HintCode.DEAD_CODE, node.rightOperand);
// Only visit the LHS:
lhsCondition?.accept(this);
return;
}
}
}
// How do we want to handle the RHS? It isn't dead code, but "pointless"
// or "obscure"...
// Expression rhsCondition = node.getRightOperand();
// ValidResult rhsResult = getConstantBooleanValue(rhsCondition);
// if (rhsResult != null) {
// if (rhsResult == ValidResult.RESULT_TRUE && isBarBar) {
// // report error on else block: !e! || true
// errorReporter.reportError(HintCode.DEAD_CODE, node.getRightOperand());
// // only visit the RHS:
// rhsCondition?.accept(this);
// return null;
// } else if (rhsResult == ValidResult.RESULT_FALSE && isAmpAmp) {
// // report error on if block: !e! && false
// errorReporter.reportError(HintCode.DEAD_CODE, node.getRightOperand());
// // only visit the RHS:
// rhsCondition?.accept(this);
// return null;
// }
// }
} else if (isQuestionQuestion && _isNonNullableUnit) {
_checkForDeadNullCoalesce(node.leftOperand.staticType, node.rightOperand);
}
super.visitBinaryExpression(node);
}
/// For each block, this method reports and error on all statements between
/// the end of the block and the first return statement (assuming there it is
/// not at the end of the block.)
@override
void visitBlock(Block node) {
NodeList<Statement> statements = node.statements;
_checkForDeadStatementsInNodeList(statements);
}
@override
void visitBreakStatement(BreakStatement node) {
labelTracker?.recordUsage(node.label?.name);
}
@override
void visitConditionalExpression(ConditionalExpression node) {
Expression conditionExpression = node.condition;
conditionExpression?.accept(this);
if (!_isDebugConstant(conditionExpression)) {
EvaluationResultImpl result =
_getConstantBooleanValue(conditionExpression);
if (result != null) {
if (result.value.toBoolValue() == true) {
// Report error on "else" block: true ? 1 : !2!
_errorReporter.reportErrorForNode(
HintCode.DEAD_CODE, node.elseExpression);
node.thenExpression?.accept(this);
return;
} else {
// Report error on "if" block: false ? !1! : 2
_errorReporter.reportErrorForNode(
HintCode.DEAD_CODE, node.thenExpression);
node.elseExpression?.accept(this);
return;
}
}
}
super.visitConditionalExpression(node);
}
@override
void visitContinueStatement(ContinueStatement node) {
labelTracker?.recordUsage(node.label?.name);
}
@override
void visitExportDirective(ExportDirective node) {
ExportElement exportElement = node.element;
if (exportElement != null) {
// The element is null when the URI is invalid.
LibraryElement library = exportElement.exportedLibrary;
if (library != null && !library.isSynthetic) {
for (Combinator combinator in node.combinators) {
_checkCombinator(library, combinator);
}
}
}
super.visitExportDirective(node);
}
@override
void visitIfElement(IfElement node) {
Expression conditionExpression = node.condition;
conditionExpression?.accept(this);
if (!_isDebugConstant(conditionExpression)) {
EvaluationResultImpl result =
_getConstantBooleanValue(conditionExpression);
if (result != null) {
if (result.value.toBoolValue() == true) {
// Report error on else block: if(true) {} else {!}
CollectionElement elseElement = node.elseElement;
if (elseElement != null) {
_errorReporter.reportErrorForNode(HintCode.DEAD_CODE, elseElement);
node.thenElement?.accept(this);
return;
}
} else {
// Report error on if block: if (false) {!} else {}
_errorReporter.reportErrorForNode(
HintCode.DEAD_CODE, node.thenElement);
node.elseElement?.accept(this);
return;
}
}
}
super.visitIfElement(node);
}
@override
void visitIfStatement(IfStatement node) {
Expression conditionExpression = node.condition;
conditionExpression?.accept(this);
if (!_isDebugConstant(conditionExpression)) {
EvaluationResultImpl result =
_getConstantBooleanValue(conditionExpression);
if (result != null) {
if (result.value.toBoolValue() == true) {
// Report error on else block: if(true) {} else {!}
Statement elseStatement = node.elseStatement;
if (elseStatement != null) {
_errorReporter.reportErrorForNode(
HintCode.DEAD_CODE, elseStatement);
node.thenStatement?.accept(this);
return;
}
} else {
// Report error on if block: if (false) {!} else {}
_errorReporter.reportErrorForNode(
HintCode.DEAD_CODE, node.thenStatement);
node.elseStatement?.accept(this);
return;
}
}
}
super.visitIfStatement(node);
}
@override
void visitImportDirective(ImportDirective node) {
ImportElement importElement = node.element;
if (importElement != null) {
// The element is null when the URI is invalid, but not when the URI is
// valid but refers to a non-existent file.
LibraryElement library = importElement.importedLibrary;
if (library != null && !library.isSynthetic) {
for (Combinator combinator in node.combinators) {
_checkCombinator(library, combinator);
}
}
}
super.visitImportDirective(node);
}
@override
void visitLabeledStatement(LabeledStatement node) {
_pushLabels(node.labels);
try {
super.visitLabeledStatement(node);
} finally {
_popLabels();
}
}
@override
void visitSwitchCase(SwitchCase node) {
_checkForDeadStatementsInNodeList(node.statements, allowMandated: true);
super.visitSwitchCase(node);
}
@override
void visitSwitchDefault(SwitchDefault node) {
_checkForDeadStatementsInNodeList(node.statements, allowMandated: true);
super.visitSwitchDefault(node);
}
@override
void visitSwitchStatement(SwitchStatement node) {
List<Label> labels = <Label>[];
for (SwitchMember member in node.members) {
labels.addAll(member.labels);
}
_pushLabels(labels);
try {
super.visitSwitchStatement(node);
} finally {
_popLabels();
}
}
@override
void visitTryStatement(TryStatement node) {
node.body?.accept(this);
node.finallyBlock?.accept(this);
NodeList<CatchClause> catchClauses = node.catchClauses;
int numOfCatchClauses = catchClauses.length;
List<DartType> visitedTypes = new List<DartType>();
for (int i = 0; i < numOfCatchClauses; i++) {
CatchClause catchClause = catchClauses[i];
if (catchClause.onKeyword != null) {
// An on-catch clause was found; verify that the exception type is not a
// subtype of a previous on-catch exception type.
DartType currentType = catchClause.exceptionType?.type;
if (currentType != null) {
if (currentType.isObject) {
// Found catch clause clause that has Object as an exception type,
// this is equivalent to having a catch clause that doesn't have an
// exception type, visit the block, but generate an error on any
// following catch clauses (and don't visit them).
catchClause?.accept(this);
if (i + 1 != numOfCatchClauses) {
// This catch clause is not the last in the try statement.
CatchClause nextCatchClause = catchClauses[i + 1];
CatchClause lastCatchClause = catchClauses[numOfCatchClauses - 1];
int offset = nextCatchClause.offset;
int length = lastCatchClause.end - offset;
_errorReporter.reportErrorForOffset(
HintCode.DEAD_CODE_CATCH_FOLLOWING_CATCH, offset, length);
return;
}
}
int length = visitedTypes.length;
for (int j = 0; j < length; j++) {
DartType type = visitedTypes[j];
if (_typeSystem.isSubtypeOf(currentType, type)) {
CatchClause lastCatchClause = catchClauses[numOfCatchClauses - 1];
int offset = catchClause.offset;
int length = lastCatchClause.end - offset;
_errorReporter.reportErrorForOffset(
HintCode.DEAD_CODE_ON_CATCH_SUBTYPE,
offset,
length,
[currentType.displayName, type.displayName]);
return;
}
}
visitedTypes.add(currentType);
}
catchClause?.accept(this);
} else {
// Found catch clause clause that doesn't have an exception type,
// visit the block, but generate an error on any following catch clauses
// (and don't visit them).
catchClause?.accept(this);
if (i + 1 != numOfCatchClauses) {
// This catch clause is not the last in the try statement.
CatchClause nextCatchClause = catchClauses[i + 1];
CatchClause lastCatchClause = catchClauses[numOfCatchClauses - 1];
int offset = nextCatchClause.offset;
int length = lastCatchClause.end - offset;
_errorReporter.reportErrorForOffset(
HintCode.DEAD_CODE_CATCH_FOLLOWING_CATCH, offset, length);
return;
}
}
}
}
@override
void visitWhileStatement(WhileStatement node) {
Expression conditionExpression = node.condition;
conditionExpression?.accept(this);
if (!_isDebugConstant(conditionExpression)) {
EvaluationResultImpl result =
_getConstantBooleanValue(conditionExpression);
if (result != null) {
if (result.value.toBoolValue() == false) {
// Report error on while block: while (false) {!}
_errorReporter.reportErrorForNode(HintCode.DEAD_CODE, node.body);
return;
}
}
}
node.body?.accept(this);
}
/// Resolve the names in the given [combinator] in the scope of the given
/// [library].
void _checkCombinator(LibraryElement library, Combinator combinator) {
Namespace namespace =
new NamespaceBuilder().createExportNamespaceForLibrary(library);
NodeList<SimpleIdentifier> names;
ErrorCode hintCode;
if (combinator is HideCombinator) {
names = combinator.hiddenNames;
hintCode = HintCode.UNDEFINED_HIDDEN_NAME;
} else {
names = (combinator as ShowCombinator).shownNames;
hintCode = HintCode.UNDEFINED_SHOWN_NAME;
}
for (SimpleIdentifier name in names) {
String nameStr = name.name;
Element element = namespace.get(nameStr);
if (element == null) {
element = namespace.get("$nameStr=");
}
if (element == null) {
_errorReporter
.reportErrorForNode(hintCode, name, [library.identifier, nameStr]);
}
}
}
void _checkForDeadNullCoalesce(TypeImpl lhsType, Expression rhs) {
if (_isNonNullableUnit && _typeSystem.isNonNullable(lhsType)) {
_errorReporter.reportErrorForNode(HintCode.DEAD_CODE, rhs, []);
}
}
/// Given some list of [statements], loop through the list searching for dead
/// statements. If [allowMandated] is true, then allow dead statements that
/// are mandated by the language spec. This allows for a final break,
/// continue, return, or throw statement at the end of a switch case, that are
/// mandated by the language spec.
void _checkForDeadStatementsInNodeList(NodeList<Statement> statements,
{bool allowMandated: false}) {
bool statementExits(Statement statement) {
if (statement is BreakStatement) {
return statement.label == null;
} else if (statement is ContinueStatement) {
return statement.label == null;
}
return ExitDetector.exits(statement);
}
int size = statements.length;
for (int i = 0; i < size; i++) {
Statement currentStatement = statements[i];
currentStatement?.accept(this);
if (statementExits(currentStatement) && i != size - 1) {
Statement nextStatement = statements[i + 1];
Statement lastStatement = statements[size - 1];
// If mandated statements are allowed, and only the last statement is
// dead, and it's a BreakStatement, then assume it is a statement
// mandated by the language spec, there to avoid a
// CASE_BLOCK_NOT_TERMINATED error.
if (allowMandated && i == size - 2 && nextStatement is BreakStatement) {
return;
}
int offset = nextStatement.offset;
int length = lastStatement.end - offset;
_errorReporter.reportErrorForOffset(HintCode.DEAD_CODE, offset, length);
return;
}
}
}
/// Given some [expression], return [ValidResult.RESULT_TRUE] if it is `true`,
/// [ValidResult.RESULT_FALSE] if it is `false`, or `null` if the expression
/// is not a constant boolean value.
EvaluationResultImpl _getConstantBooleanValue(Expression expression) {
if (expression is BooleanLiteral) {
if (expression.value) {
return new EvaluationResultImpl(
new DartObjectImpl(null, BoolState.from(true)));
} else {
return new EvaluationResultImpl(
new DartObjectImpl(null, BoolState.from(false)));
}
}
// Don't consider situations where we could evaluate to a constant boolean
// expression with the ConstantVisitor
// else {
// EvaluationResultImpl result = expression.accept(new ConstantVisitor());
// if (result == ValidResult.RESULT_TRUE) {
// return ValidResult.RESULT_TRUE;
// } else if (result == ValidResult.RESULT_FALSE) {
// return ValidResult.RESULT_FALSE;
// }
// return null;
// }
return null;
}
/// Return `true` if the given [expression] is resolved to a constant
/// variable.
bool _isDebugConstant(Expression expression) {
Element element = null;
if (expression is Identifier) {
element = expression.staticElement;
} else if (expression is PropertyAccess) {
element = expression.propertyName.staticElement;
}
if (element is PropertyAccessorElement) {
PropertyInducingElement variable = element.variable;
return variable != null && variable.isConst;
}
return false;
}
/// Exit the most recently entered label scope after reporting any labels that
/// were not referenced within that scope.
void _popLabels() {
for (Label label in labelTracker.unusedLabels()) {
_errorReporter
.reportErrorForNode(HintCode.UNUSED_LABEL, label, [label.label.name]);
}
labelTracker = labelTracker.outerTracker;
}
/// Enter a new label scope in which the given [labels] are defined.
void _pushLabels(List<Label> labels) {
labelTracker = new _LabelTracker(labelTracker, labels);
}
}
/// A visitor that resolves directives in an AST structure to already built
/// elements.
///
/// The resulting AST must have everything resolved that would have been
/// resolved by a [DirectiveElementBuilder].
class DirectiveResolver extends SimpleAstVisitor {
final Map<Source, int> sourceModificationTimeMap;
final Map<Source, SourceKind> importSourceKindMap;
final Map<Source, SourceKind> exportSourceKindMap;
final List<AnalysisError> errors = <AnalysisError>[];
LibraryElement _enclosingLibrary;
DirectiveResolver(this.sourceModificationTimeMap, this.importSourceKindMap,
this.exportSourceKindMap);
@override
void visitCompilationUnit(CompilationUnit node) {
_enclosingLibrary =
resolutionMap.elementDeclaredByCompilationUnit(node).library;
for (Directive directive in node.directives) {
directive.accept(this);
}
}
@override
void visitExportDirective(ExportDirective node) {
int nodeOffset = node.offset;
node.element = null;
for (ExportElement element in _enclosingLibrary.exports) {
if (element.nameOffset == nodeOffset) {
node.element = element;
// Verify the exported source kind.
LibraryElement exportedLibrary = element.exportedLibrary;
if (exportedLibrary != null) {
Source exportedSource = exportedLibrary.source;
int exportedTime = sourceModificationTimeMap[exportedSource] ?? -1;
if (exportedTime >= 0 &&
exportSourceKindMap[exportedSource] != SourceKind.LIBRARY) {
StringLiteral uriLiteral = node.uri;
errors.add(new AnalysisError(
_enclosingLibrary.source,
uriLiteral.offset,
uriLiteral.length,
CompileTimeErrorCode.EXPORT_OF_NON_LIBRARY,
[uriLiteral.toSource()]));
}
}
break;
}
}
}
@override
void visitImportDirective(ImportDirective node) {
int nodeOffset = node.offset;
node.element = null;
for (ImportElement element in _enclosingLibrary.imports) {
if (element.nameOffset == nodeOffset) {
node.element = element;
// Verify the imported source kind.
LibraryElement importedLibrary = element.importedLibrary;
if (importedLibrary != null) {
Source importedSource = importedLibrary.source;
int importedTime = sourceModificationTimeMap[importedSource] ?? -1;
if (importedTime >= 0 &&
importSourceKindMap[importedSource] != SourceKind.LIBRARY) {
StringLiteral uriLiteral = node.uri;
ErrorCode errorCode = element.isDeferred
? StaticWarningCode.IMPORT_OF_NON_LIBRARY
: CompileTimeErrorCode.IMPORT_OF_NON_LIBRARY;
errors.add(new AnalysisError(
_enclosingLibrary.source,
uriLiteral.offset,
uriLiteral.length,
errorCode,
[uriLiteral.toSource()]));
}
}
break;
}
}
}
@override
void visitLibraryDirective(LibraryDirective node) {
node.element = _enclosingLibrary;
}
}
/// Instances of the class `ElementHolder` hold on to elements created while
/// traversing an AST structure so that they can be accessed when creating their
/// enclosing element.
class ElementHolder {
List<PropertyAccessorElement> _accessors;
List<ConstructorElement> _constructors;
List<ClassElement> _enums;
List<FieldElement> _fields;
List<FunctionElement> _functions;
List<LabelElement> _labels;
List<LocalVariableElement> _localVariables;
List<MethodElement> _methods;
List<ClassElement> _mixins;
List<ParameterElement> _parameters;
List<TopLevelVariableElement> _topLevelVariables;
List<ClassElement> _types;
List<FunctionTypeAliasElement> _typeAliases;
List<TypeParameterElement> _typeParameters;
List<PropertyAccessorElement> get accessors {
if (_accessors == null) {
return const <PropertyAccessorElement>[];
}
List<PropertyAccessorElement> result = _accessors;
_accessors = null;
return result;
}
List<ConstructorElement> get constructors {
if (_constructors == null) {
return const <ConstructorElement>[];
}
List<ConstructorElement> result = _constructors;
_constructors = null;
return result;
}
List<ClassElement> get enums {
if (_enums == null) {
return const <ClassElement>[];
}
List<ClassElement> result = _enums;
_enums = null;
return result;
}
List<FieldElement> get fields {
if (_fields == null) {
return const <FieldElement>[];
}
List<FieldElement> result = _fields;
_fields = null;
return result;
}
List<FieldElement> get fieldsWithoutFlushing {
if (_fields == null) {
return const <FieldElement>[];
}
List<FieldElement> result = _fields;
return result;
}
List<FunctionElement> get functions {
if (_functions == null) {
return const <FunctionElement>[];
}
List<FunctionElement> result = _functions;
_functions = null;
return result;
}
List<LabelElement> get labels {
if (_labels == null) {
return const <LabelElement>[];
}
List<LabelElement> result = _labels;
_labels = null;
return result;
}
List<LocalVariableElement> get localVariables {
if (_localVariables == null) {
return const <LocalVariableElement>[];
}
List<LocalVariableElement> result = _localVariables;
_localVariables = null;
return result;
}
List<MethodElement> get methods {
if (_methods == null) {
return const <MethodElement>[];
}
List<MethodElement> result = _methods;
_methods = null;
return result;
}
List<ClassElement> get mixins {
if (_mixins == null) {
return const <ClassElement>[];
}
List<ClassElement> result = _mixins;
_mixins = null;
return result;
}
List<ParameterElement> get parameters {
if (_parameters == null) {
return const <ParameterElement>[];
}
List<ParameterElement> result = _parameters;
_parameters = null;
return result;
}
List<TopLevelVariableElement> get topLevelVariables {
if (_topLevelVariables == null) {
return const <TopLevelVariableElement>[];
}
List<TopLevelVariableElement> result = _topLevelVariables;
_topLevelVariables = null;
return result;
}
List<FunctionTypeAliasElement> get typeAliases {
if (_typeAliases == null) {
return const <FunctionTypeAliasElement>[];
}
List<FunctionTypeAliasElement> result = _typeAliases;
_typeAliases = null;
return result;
}
List<TypeParameterElement> get typeParameters {
if (_typeParameters == null) {
return const <TypeParameterElement>[];
}
List<TypeParameterElement> result = _typeParameters;
_typeParameters = null;
return result;
}
List<ClassElement> get types {
if (_types == null) {
return const <ClassElement>[];
}
List<ClassElement> result = _types;
_types = null;
return result;
}
void addAccessor(PropertyAccessorElement element) {
if (_accessors == null) {
_accessors = new List<PropertyAccessorElement>();
}
_accessors.add(element);
}
void addConstructor(ConstructorElement element) {
if (_constructors == null) {
_constructors = new List<ConstructorElement>();
}
_constructors.add(element);
}
void addEnum(ClassElement element) {
if (_enums == null) {
_enums = new List<ClassElement>();
}
_enums.add(element);
}
void addField(FieldElement element) {
if (_fields == null) {
_fields = new List<FieldElement>();
}
_fields.add(element);
}
void addFunction(FunctionElement element) {
if (_functions == null) {
_functions = new List<FunctionElement>();
}
_functions.add(element);
}
void addLabel(LabelElement element) {
if (_labels == null) {
_labels = new List<LabelElement>();
}
_labels.add(element);
}
void addLocalVariable(LocalVariableElement element) {
if (_localVariables == null) {
_localVariables = new List<LocalVariableElement>();
}
_localVariables.add(element);
}
void addMethod(MethodElement element) {
if (_methods == null) {
_methods = new List<MethodElement>();
}
_methods.add(element);
}
void addMixin(ClassElement element) {
if (_mixins == null) {
_mixins = new List<ClassElement>();
}
_mixins.add(element);
}
void addParameter(ParameterElement element) {
if (_parameters == null) {
_parameters = new List<ParameterElement>();
}
_parameters.add(element);
}
void addTopLevelVariable(TopLevelVariableElement element) {
if (_topLevelVariables == null) {
_topLevelVariables = new List<TopLevelVariableElement>();
}
_topLevelVariables.add(element);
}
void addType(ClassElement element) {
if (_types == null) {
_types = new List<ClassElement>();
}
_types.add(element);
}
void addTypeAlias(FunctionTypeAliasElement element) {
if (_typeAliases == null) {
_typeAliases = new List<FunctionTypeAliasElement>();
}
_typeAliases.add(element);
}
void addTypeParameter(TypeParameterElement element) {
if (_typeParameters == null) {
_typeParameters = new List<TypeParameterElement>();
}
_typeParameters.add(element);
}
FieldElement getField(String fieldName, {bool synthetic: false}) {
if (_fields == null) {
return null;
}
int length = _fields.length;
for (int i = 0; i < length; i++) {
FieldElement field = _fields[i];
if (field.name == fieldName && field.isSynthetic == synthetic) {
return field;
}
}
return null;
}
TopLevelVariableElement getTopLevelVariable(String variableName) {
if (_topLevelVariables == null) {
return null;
}
int length = _topLevelVariables.length;
for (int i = 0; i < length; i++) {
TopLevelVariableElement variable = _topLevelVariables[i];
if (variable.name == variableName) {
return variable;
}
}
return null;
}
void validate() {
StringBuffer buffer = new StringBuffer();
if (_accessors != null) {
buffer.write(_accessors.length);
buffer.write(" accessors");
}
if (_constructors != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_constructors.length);
buffer.write(" constructors");
}
if (_fields != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_fields.length);
buffer.write(" fields");
}
if (_functions != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_functions.length);
buffer.write(" functions");
}
if (_labels != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_labels.length);
buffer.write(" labels");
}
if (_localVariables != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_localVariables.length);
buffer.write(" local variables");
}
if (_methods != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_methods.length);
buffer.write(" methods");
}
if (_parameters != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_parameters.length);
buffer.write(" parameters");
}
if (_topLevelVariables != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_topLevelVariables.length);
buffer.write(" top-level variables");
}
if (_types != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_types.length);
buffer.write(" types");
}
if (_typeAliases != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_typeAliases.length);
buffer.write(" type aliases");
}
if (_typeParameters != null) {
if (buffer.length > 0) {
buffer.write("; ");
}
buffer.write(_typeParameters.length);
buffer.write(" type parameters");
}
if (buffer.length > 0) {
AnalysisEngine.instance.logger
.logError("Failed to capture elements: $buffer");
}
}
}
/// Instances of the class `EnumMemberBuilder` build the members in enum
/// declarations.
class EnumMemberBuilder extends RecursiveAstVisitor<void> {
/// The type provider used to access the types needed to build an element
/// model for enum declarations.
final TypeProvider _typeProvider;
/// Initialize a newly created enum member builder.
///
/// @param typeProvider the type provider used to access the types needed to
/// build an element model for enum declarations
EnumMemberBuilder(this._typeProvider);
@override
void visitEnumDeclaration(EnumDeclaration node) {
//
// Finish building the enum.
//
EnumElementImpl enumElement = node.name.staticElement as EnumElementImpl;
InterfaceType enumType = enumElement.type;
//
// Populate the fields.
//
List<FieldElement> fields = new List<FieldElement>();
List<PropertyAccessorElement> getters = new List<PropertyAccessorElement>();
InterfaceType intType = _typeProvider.intType;
String indexFieldName = "index";
FieldElementImpl indexField = new FieldElementImpl(indexFieldName, -1);
indexField.isFinal = true;
indexField.isSynthetic = true;
indexField.type = intType;
fields.add(indexField);
getters.add(_createGetter(indexField));
ConstFieldElementImpl valuesField = new ConstFieldElementImpl("values", -1);
valuesField.isStatic = true;
valuesField.isConst = true;
valuesField.isSynthetic = true;
valuesField.type = _typeProvider.listType.instantiate(<DartType>[enumType]);
fields.add(valuesField);
getters.add(_createGetter(valuesField));
//
// Build the enum constants.
//
NodeList<EnumConstantDeclaration> constants = node.constants;
List<DartObjectImpl> constantValues = new List<DartObjectImpl>();
int constantCount = constants.length;
for (int i = 0; i < constantCount; i++) {
EnumConstantDeclaration constant = constants[i];
FieldElementImpl constantField = constant.name.staticElement;
//
// Create a value for the constant.
//
Map<String, DartObjectImpl> fieldMap =
new HashMap<String, DartObjectImpl>();
fieldMap[indexFieldName] = new DartObjectImpl(intType, new IntState(i));
DartObjectImpl value =
new DartObjectImpl(enumType, new GenericState(fieldMap));
constantValues.add(value);
constantField.evaluationResult = new EvaluationResultImpl(value);
fields.add(constantField);
getters.add(constantField.getter);
}
//
// Build the value of the 'values' field.
//
valuesField.evaluationResult = new EvaluationResultImpl(
new DartObjectImpl(valuesField.type, new ListState(constantValues)));
// Update toString() return type.
{
MethodElementImpl toStringMethod = enumElement.methods[0];
toStringMethod.returnType = _typeProvider.stringType;
toStringMethod.type = new FunctionTypeImpl(toStringMethod);
}
//
// Finish building the enum.
//
enumElement.fields = fields;
enumElement.accessors = getters;
// Client code isn't allowed to invoke the constructor, so we do not model
// it.
super.visitEnumDeclaration(node);
}
/// Create a getter that corresponds to the given [field].
PropertyAccessorElement _createGetter(FieldElementImpl field) {
return new PropertyAccessorElementImpl_ImplicitGetter(field);
}
}
/// A visitor that visits ASTs and fills [UsedImportedElements].
class GatherUsedImportedElementsVisitor extends RecursiveAstVisitor {
final LibraryElement library;
final UsedImportedElements usedElements = new UsedImportedElements();
GatherUsedImportedElementsVisitor(this.library);
@override
void visitExportDirective(ExportDirective node) {
_visitDirective(node);
}
@override
void visitImportDirective(ImportDirective node) {
_visitDirective(node);
}
@override
void visitLibraryDirective(LibraryDirective node) {
_visitDirective(node);
}
@override
void visitSimpleIdentifier(SimpleIdentifier node) {
_visitIdentifier(node, node.staticElement);
}
/// If the given [identifier] is prefixed with a [PrefixElement], fill the
/// corresponding `UsedImportedElements.prefixMap` entry and return `true`.
bool _recordPrefixMap(SimpleIdentifier identifier, Element element) {
bool recordIfTargetIsPrefixElement(Expression target) {
if (target is SimpleIdentifier && target.staticElement is PrefixElement) {
List<Element> prefixedElements = usedElements.prefixMap
.putIfAbsent(target.staticElement, () => <Element>[]);
prefixedElements.add(element);
return true;
}
return false;
}
AstNode parent = identifier.parent;
if (parent is MethodInvocation && parent.methodName == identifier) {
return recordIfTargetIsPrefixElement(parent.target);
}
if (parent is PrefixedIdentifier && parent.identifier == identifier) {
return recordIfTargetIsPrefixElement(parent.prefix);
}
return false;
}
/// Visit identifiers used by the given [directive].
void _visitDirective(Directive directive) {
directive.documentationComment?.accept(this);
directive.metadata.accept(this);
}
void _visitIdentifier(SimpleIdentifier identifier, Element element) {
if (element == null) {
return;
}
// If the element is multiply defined then call this method recursively for
// each of the conflicting elements.
if (element is MultiplyDefinedElement) {
List<Element> conflictingElements = element.conflictingElements;
int length = conflictingElements.length;
for (int i = 0; i < length; i++) {
Element elt = conflictingElements[i];
_visitIdentifier(identifier, elt);
}
return;
}
// Record `importPrefix.identifier` into 'prefixMap'.
if (_recordPrefixMap(identifier, element)) {
return;
}
if (element is PrefixElement) {
usedElements.prefixMap.putIfAbsent(element, () => <Element>[]);
return;
} else if (element.enclosingElement is! CompilationUnitElement) {
// Identifiers that aren't a prefix element and whose enclosing element
// isn't a CompilationUnit are ignored- this covers the case the
// identifier is a relative-reference, a reference to an identifier not
// imported by this library.
return;
}
// Ignore if an unknown library.
LibraryElement containingLibrary = element.library;
if (containingLibrary == null) {
return;
}
// Ignore if a local element.
if (library == containingLibrary) {
return;
}
// Remember the element.
usedElements.elements.add(element);
}
}
/// An [AstVisitor] that fills [UsedLocalElements].
class GatherUsedLocalElementsVisitor extends RecursiveAstVisitor {
final UsedLocalElements usedElements = new UsedLocalElements();
final LibraryElement _enclosingLibrary;
ClassElement _enclosingClass;
ExecutableElement _enclosingExec;
GatherUsedLocalElementsVisitor(this._enclosingLibrary);
@override
visitCatchClause(CatchClause node) {
SimpleIdentifier exceptionParameter = node.exceptionParameter;
SimpleIdentifier stackTraceParameter = node.stackTraceParameter;
if (exceptionParameter != null) {
Element element = exceptionParameter.staticElement;
usedElements.addCatchException(element);
if (stackTraceParameter != null || node.onKeyword == null) {
usedElements.addElement(element);
}
}
if (stackTraceParameter != null) {
Element element = stackTraceParameter.staticElement;
usedElements.addCatchStackTrace(element);
}
super.visitCatchClause(node);
}
@override
visitClassDeclaration(ClassDeclaration node) {
ClassElement enclosingClassOld = _enclosingClass;
try {
_enclosingClass = node.declaredElement;
super.visitClassDeclaration(node);
} finally {
_enclosingClass = enclosingClassOld;
}
}
@override
visitFunctionDeclaration(FunctionDeclaration node) {
ExecutableElement enclosingExecOld = _enclosingExec;
try {
_enclosingExec = node.declaredElement;
super.visitFunctionDeclaration(node);
} finally {
_enclosingExec = enclosingExecOld;
}
}
@override
visitFunctionExpression(FunctionExpression node) {
if (node.parent is! FunctionDeclaration) {
usedElements.addElement(node.declaredElement);
}
super.visitFunctionExpression(node);
}
@override
visitMethodDeclaration(MethodDeclaration node) {
ExecutableElement enclosingExecOld = _enclosingExec;
try {
_enclosingExec = node.declaredElement;
super.visitMethodDeclaration(node);
} finally {
_enclosingExec = enclosingExecOld;
}
}
@override
visitSimpleIdentifier(SimpleIdentifier node) {
if (node.inDeclarationContext()) {
return;</