| // 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. |
| |
| /** |
| * Code for classifying the semantics of identifiers appearing in a Dart file. |
| */ |
| library analyzer2dart.identifierSemantics; |
| |
| import 'package:analyzer/analyzer.dart'; |
| import 'package:analyzer/src/generated/element.dart'; |
| |
| // TODO(johnniwinther,paulberry): This should be a constant. |
| final AccessSemanticsVisitor ACCESS_SEMANTICS_VISITOR = |
| new AccessSemanticsVisitor(); |
| |
| /** |
| * Enum representing the different kinds of destinations which a property |
| * access or method or function invocation might refer to. |
| */ |
| class AccessKind { |
| /** |
| * The destination of the access is an instance method, property, or field |
| * of a class, and thus must be determined dynamically. |
| */ |
| static const AccessKind DYNAMIC = const AccessKind._('DYNAMIC'); |
| |
| /** |
| * The destination of the access is a function that is defined locally within |
| * an enclosing function or method. |
| */ |
| static const AccessKind LOCAL_FUNCTION = const AccessKind._('LOCAL_FUNCTION'); |
| |
| /** |
| * The destination of the access is a variable that is defined locally within |
| * an enclosing function or method. |
| */ |
| static const AccessKind LOCAL_VARIABLE = const AccessKind._('LOCAL_VARIABLE'); |
| |
| /** |
| * The destination of the access is a variable that is defined as a parameter |
| * to an enclosing function or method. |
| */ |
| static const AccessKind PARAMETER = const AccessKind._('PARAMETER'); |
| |
| /** |
| * The destination of the access is a field that is defined statically within |
| * a class, or a top level variable within a library. |
| */ |
| static const AccessKind STATIC_FIELD = const AccessKind._('STATIC_FIELD'); |
| |
| /** |
| * The destination of the access is a method that is defined statically |
| * within a class, or at top level within a library. |
| */ |
| static const AccessKind STATIC_METHOD = const AccessKind._('STATIC_METHOD'); |
| |
| /** |
| * The destination of the access is a property getter/setter that is defined |
| * statically within a class, or at top level within a library. |
| */ |
| static const AccessKind STATIC_PROPERTY = |
| const AccessKind._('STATIC_PROPERTY'); |
| |
| /** |
| * The destination of the access is a toplevel class, function typedef, mixin |
| * application, or the built-in type "dynamic". |
| */ |
| static const AccessKind TOPLEVEL_TYPE = const AccessKind._('TOPLEVEL_TYPE'); |
| |
| /** |
| * The destination of the access is a type parameter of the enclosing class. |
| */ |
| static const AccessKind TYPE_PARAMETER = const AccessKind._('TYPE_PARAMETER'); |
| |
| final String name; |
| |
| const AccessKind._(this.name); |
| |
| String toString() => name; |
| } |
| |
| /** |
| * Data structure used to classify the semantics of a property access or method |
| * or function invocation. |
| */ |
| // TODO(paulberry,johnniwinther): Support index operations in AccessSemantics. |
| class AccessSemantics { |
| /** |
| * The kind of access. |
| */ |
| final AccessKind kind; |
| |
| /** |
| * The identifier being used to access the property, method, or function. |
| */ |
| final SimpleIdentifier identifier; |
| |
| /** |
| * The element being accessed, if statically known. This will be null if |
| * [kind] is DYNAMIC or if the element is undefined (e.g. an attempt to |
| * access a non-existent static method in a class). |
| */ |
| final Element element; |
| |
| /** |
| * The class containing the element being accessed, if this is a static |
| * reference to an element in a class. This will be null if [kind] is |
| * DYNAMIC, LOCAL_FUNCTION, LOCAL_VARIABLE, PARAMETER, TOPLEVEL_CLASS, or |
| * TYPE_PARAMETER, or if the element being accessed is defined at toplevel |
| * within a library. |
| * |
| * Note: it is possible for [classElement] to be non-null and for [element] |
| * to be null; for example this occurs if the element being accessed is a |
| * non-existent static method or field inside an existing class. |
| */ |
| final ClassElement classElement; |
| |
| // TODO(paulberry): would it also be useful to store the libraryElement? |
| |
| /** |
| * When [kind] is DYNAMIC, the expression whose runtime type determines the |
| * class in which [identifier] should be looked up. Null if the expression |
| * is implicit "this". |
| * |
| * When [kind] is not DYNAMIC, this field is always null. |
| */ |
| final Expression target; |
| |
| /** |
| * True if this is an invocation of a method, or a call on a property. |
| */ |
| final bool isInvoke; |
| |
| AccessSemantics.dynamic(this.identifier, this.target, {this.isInvoke: false}) |
| : kind = AccessKind.DYNAMIC, |
| element = null, |
| classElement = null; |
| |
| AccessSemantics.localFunction(this.identifier, this.element, {this.isInvoke: |
| false}) |
| : kind = AccessKind.LOCAL_FUNCTION, |
| classElement = null, |
| target = null; |
| |
| AccessSemantics.localVariable(this.identifier, this.element, {this.isInvoke: |
| false}) |
| : kind = AccessKind.LOCAL_VARIABLE, |
| classElement = null, |
| target = null; |
| |
| AccessSemantics.parameter(this.identifier, this.element, {this.isInvoke: |
| false}) |
| : kind = AccessKind.PARAMETER, |
| classElement = null, |
| target = null; |
| |
| AccessSemantics.staticField(this.identifier, this.element, this.classElement, |
| {this.isInvoke: false}) |
| : kind = AccessKind.STATIC_FIELD, |
| target = null; |
| |
| AccessSemantics.staticMethod(this.identifier, this.element, this.classElement, |
| {this.isInvoke: false}) |
| : kind = AccessKind.STATIC_METHOD, |
| target = null; |
| |
| AccessSemantics.staticProperty(this.identifier, this.element, |
| this.classElement, {this.isInvoke: false}) |
| : kind = AccessKind.STATIC_PROPERTY, |
| target = null; |
| |
| AccessSemantics.toplevelType(this.identifier, this.element, {this.isInvoke: |
| false}) |
| : kind = AccessKind.TOPLEVEL_TYPE, |
| classElement = null, |
| target = null; |
| |
| AccessSemantics.typeParameter(this.identifier, this.element, {this.isInvoke: |
| false}) |
| : kind = AccessKind.TYPE_PARAMETER, |
| classElement = null, |
| target = null; |
| |
| /** |
| * True if this is a read access to a property, or a method tear-off. Note |
| * that both [isRead] and [isWrite] will be true in the case of a |
| * read-modify-write operation (e.g. "+="). |
| */ |
| bool get isRead => !isInvoke && identifier.inGetterContext(); |
| |
| /** |
| * True if this is a write access to a property, or an (erroneous) attempt to |
| * write to a method. Note that both [isRead] and [isWrite] will be true in |
| * the case of a read-modify-write operation (e.g. "+="). |
| */ |
| bool get isWrite => identifier.inSetterContext(); |
| |
| String toString() { |
| StringBuffer sb = new StringBuffer(); |
| sb.write('AccessSemantics['); |
| sb.write('kind=$kind,'); |
| if (isRead && isWrite) { |
| assert(!isInvoke); |
| sb.write('read/write,'); |
| } else if (isRead) { |
| sb.write('read,'); |
| } else if (isWrite) { |
| sb.write('write,'); |
| } else if (isInvoke) { |
| sb.write('call,'); |
| } |
| if (element != null) { |
| sb.write('element='); |
| if (classElement != null) { |
| sb.write('${classElement.name}.'); |
| } |
| sb.write('${element}'); |
| } else { |
| if (target == null) { |
| sb.write('target=this.$identifier'); |
| } else { |
| sb.write('target=$target.$identifier'); |
| } |
| } |
| sb.write(']'); |
| return sb.toString(); |
| } |
| } |
| |
| // TODO(johnniwinther,paulberry): This should extend a non-recursive visitor. |
| class AccessSemanticsVisitor extends RecursiveAstVisitor<AccessSemantics> { |
| /** |
| * Return the semantics for [node]. |
| */ |
| @override |
| AccessSemantics visitMethodInvocation(MethodInvocation node) { |
| Expression target = node.realTarget; |
| Element staticElement = node.methodName.staticElement; |
| if (target == null) { |
| if (staticElement is FunctionElement) { |
| if (staticElement.enclosingElement is CompilationUnitElement) { |
| return new AccessSemantics.staticMethod( |
| node.methodName, |
| staticElement, |
| null, |
| isInvoke: true); |
| } else { |
| return new AccessSemantics.localFunction( |
| node.methodName, |
| staticElement, |
| isInvoke: true); |
| } |
| } else if (staticElement is MethodElement && staticElement.isStatic) { |
| return new AccessSemantics.staticMethod( |
| node.methodName, |
| staticElement, |
| staticElement.enclosingElement, |
| isInvoke: true); |
| } else if (staticElement is PropertyAccessorElement) { |
| if (staticElement.isSynthetic) { |
| if (staticElement.enclosingElement is CompilationUnitElement) { |
| return new AccessSemantics.staticField( |
| node.methodName, |
| staticElement.variable, |
| null, |
| isInvoke: true); |
| } else if (staticElement.isStatic) { |
| return new AccessSemantics.staticField( |
| node.methodName, |
| staticElement.variable, |
| staticElement.enclosingElement, |
| isInvoke: true); |
| } |
| } else { |
| if (staticElement.enclosingElement is CompilationUnitElement) { |
| return new AccessSemantics.staticProperty( |
| node.methodName, |
| staticElement, |
| null, |
| isInvoke: true); |
| } else if (staticElement.isStatic) { |
| return new AccessSemantics.staticProperty( |
| node.methodName, |
| staticElement, |
| staticElement.enclosingElement, |
| isInvoke: true); |
| } |
| } |
| } else if (staticElement is LocalVariableElement) { |
| return new AccessSemantics.localVariable( |
| node.methodName, |
| staticElement, |
| isInvoke: true); |
| } else if (staticElement is ParameterElement) { |
| return new AccessSemantics.parameter( |
| node.methodName, |
| staticElement, |
| isInvoke: true); |
| } else if (staticElement is TypeParameterElement) { |
| return new AccessSemantics.typeParameter( |
| node.methodName, |
| staticElement, |
| isInvoke: true); |
| } else if (staticElement is ClassElement || |
| staticElement is FunctionTypeAliasElement || |
| staticElement is DynamicElementImpl) { |
| return new AccessSemantics.toplevelType( |
| node.methodName, |
| staticElement, |
| isInvoke: true); |
| } |
| } else if (target is Identifier) { |
| Element targetStaticElement = target.staticElement; |
| if (targetStaticElement is PrefixElement) { |
| if (staticElement == null) { |
| return new AccessSemantics.dynamic( |
| node.methodName, |
| null, |
| isInvoke: true); |
| } else if (staticElement is PropertyAccessorElement) { |
| if (staticElement.isSynthetic) { |
| return new AccessSemantics.staticField( |
| node.methodName, |
| staticElement.variable, |
| null, |
| isInvoke: true); |
| } else { |
| return new AccessSemantics.staticProperty( |
| node.methodName, |
| staticElement, |
| null, |
| isInvoke: true); |
| } |
| } else if (staticElement is TypeParameterElement) { |
| return new AccessSemantics.typeParameter( |
| node.methodName, |
| staticElement, |
| isInvoke: true); |
| } else if (staticElement is ClassElement || |
| staticElement is FunctionTypeAliasElement) { |
| return new AccessSemantics.toplevelType( |
| node.methodName, |
| staticElement, |
| isInvoke: true); |
| } else { |
| return new AccessSemantics.staticMethod( |
| node.methodName, |
| staticElement, |
| null, |
| isInvoke: true); |
| } |
| } else if (targetStaticElement is ClassElement) { |
| if (staticElement is PropertyAccessorElement) { |
| if (staticElement.isSynthetic) { |
| return new AccessSemantics.staticField( |
| node.methodName, |
| staticElement.variable, |
| targetStaticElement, |
| isInvoke: true); |
| } else { |
| return new AccessSemantics.staticProperty( |
| node.methodName, |
| staticElement, |
| targetStaticElement, |
| isInvoke: true); |
| } |
| } else { |
| return new AccessSemantics.staticMethod( |
| node.methodName, |
| staticElement, |
| targetStaticElement, |
| isInvoke: true); |
| } |
| } |
| } |
| return new AccessSemantics.dynamic(node.methodName, target, isInvoke: true); |
| } |
| |
| /** |
| * Return the access semantics for [node]. |
| */ |
| @override |
| AccessSemantics visitPrefixedIdentifier(PrefixedIdentifier node) { |
| return _classifyPrefixed(node.prefix, node.identifier); |
| } |
| |
| /** |
| * Return the access semantics for [node]. |
| */ |
| @override |
| AccessSemantics visitPropertyAccess(PropertyAccess node) { |
| if (node.target is Identifier) { |
| return _classifyPrefixed(node.target, node.propertyName); |
| } else { |
| return new AccessSemantics.dynamic(node.propertyName, node.realTarget); |
| } |
| } |
| |
| /** |
| * Return the access semantics for [node]. |
| * |
| * Note: if [node] is the right hand side of a [PropertyAccess] or |
| * [PrefixedIdentifier], or the method name of a [MethodInvocation], the return |
| * value is null, since the semantics are determined by the parent. In |
| * practice these cases should never arise because the parent will visit the |
| * parent node before visiting this one. |
| */ |
| @override |
| AccessSemantics visitSimpleIdentifier(SimpleIdentifier node) { |
| AstNode parent = node.parent; |
| if (node.inDeclarationContext()) { |
| // This identifier is a declaration, not a use. |
| return null; |
| } |
| if (parent is TypeName) { |
| // TODO(paulberry): do we need to handle this case? |
| return null; |
| } |
| if ((parent is PropertyAccess && parent.propertyName == node) || |
| (parent is PrefixedIdentifier && parent.identifier == node) || |
| (parent is MethodInvocation && parent.methodName == node)) { |
| // The access semantics are determined by the parent. |
| return null; |
| } |
| // TODO(paulberry): handle PrefixElement. |
| Element staticElement = node.staticElement; |
| if (staticElement is PropertyAccessorElement) { |
| if (staticElement.isSynthetic) { |
| if (staticElement.enclosingElement is CompilationUnitElement) { |
| return new AccessSemantics.staticField( |
| node, |
| staticElement.variable, |
| null); |
| } else if (staticElement.isStatic) { |
| return new AccessSemantics.staticField( |
| node, |
| staticElement.variable, |
| staticElement.enclosingElement); |
| } |
| } else { |
| if (staticElement.enclosingElement is CompilationUnitElement) { |
| return new AccessSemantics.staticProperty(node, staticElement, null); |
| } else if (staticElement.isStatic) { |
| return new AccessSemantics.staticProperty( |
| node, |
| staticElement, |
| staticElement.enclosingElement); |
| } |
| } |
| } else if (staticElement is LocalVariableElement) { |
| return new AccessSemantics.localVariable(node, staticElement); |
| } else if (staticElement is ParameterElement) { |
| return new AccessSemantics.parameter(node, staticElement); |
| } else if (staticElement is FunctionElement) { |
| if (staticElement.enclosingElement is CompilationUnitElement) { |
| return new AccessSemantics.staticMethod(node, staticElement, null); |
| } else { |
| return new AccessSemantics.localFunction(node, staticElement); |
| } |
| } else if (staticElement is MethodElement && staticElement.isStatic) { |
| return new AccessSemantics.staticMethod( |
| node, |
| staticElement, |
| staticElement.enclosingElement); |
| } else if (staticElement is TypeParameterElement) { |
| return new AccessSemantics.typeParameter(node, staticElement); |
| } else if (staticElement is ClassElement || |
| staticElement is FunctionTypeAliasElement || |
| staticElement is DynamicElementImpl) { |
| return new AccessSemantics.toplevelType(node, staticElement); |
| } |
| return new AccessSemantics.dynamic(node, null); |
| } |
| |
| /** |
| * Helper function for classifying an expression of type |
| * Identifier.SimpleIdentifier. |
| */ |
| AccessSemantics _classifyPrefixed(Identifier lhs, SimpleIdentifier rhs) { |
| Element lhsElement = lhs.staticElement; |
| Element rhsElement = rhs.staticElement; |
| if (lhsElement is PrefixElement) { |
| if (rhsElement is PropertyAccessorElement) { |
| if (rhsElement.isSynthetic) { |
| return new AccessSemantics.staticField( |
| rhs, |
| rhsElement.variable, |
| null); |
| } else { |
| return new AccessSemantics.staticProperty(rhs, rhsElement, null); |
| } |
| } else if (rhsElement is FunctionElement) { |
| return new AccessSemantics.staticMethod(rhs, rhsElement, null); |
| } else if (rhsElement is ClassElement || |
| rhsElement is FunctionTypeAliasElement) { |
| return new AccessSemantics.toplevelType(rhs, rhsElement); |
| } else { |
| return new AccessSemantics.dynamic(rhs, null); |
| } |
| } else if (lhsElement is ClassElement) { |
| if (rhsElement is PropertyAccessorElement && rhsElement.isSynthetic) { |
| return new AccessSemantics.staticField( |
| rhs, |
| rhsElement.variable, |
| lhsElement); |
| } else if (rhsElement is MethodElement) { |
| return new AccessSemantics.staticMethod(rhs, rhsElement, lhsElement); |
| } else { |
| return new AccessSemantics.staticProperty(rhs, rhsElement, lhsElement); |
| } |
| } else { |
| return new AccessSemantics.dynamic(rhs, lhs); |
| } |
| } |
| } |
