/*
* Copyright (c) 2013, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.eclipse.org/legal/epl-v10.html
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.dart.engine.internal.resolver;
import com.google.dart.engine.ast.AstNode;
import com.google.dart.engine.ast.ConstructorName;
import com.google.dart.engine.ast.ExportDirective;
import com.google.dart.engine.ast.FunctionDeclaration;
import com.google.dart.engine.ast.FunctionExpression;
import com.google.dart.engine.ast.ImportDirective;
import com.google.dart.engine.ast.Label;
import com.google.dart.engine.ast.MethodDeclaration;
import com.google.dart.engine.ast.MethodInvocation;
import com.google.dart.engine.ast.PrefixedIdentifier;
import com.google.dart.engine.ast.PropertyAccess;
import com.google.dart.engine.ast.SimpleIdentifier;
import com.google.dart.engine.element.Element;
import com.google.dart.engine.element.ElementKind;
import com.google.dart.engine.element.ExecutableElement;
import com.google.dart.engine.element.LibraryElement;
import com.google.dart.engine.element.VariableElement;
import com.google.dart.engine.error.AnalysisErrorListener;
import com.google.dart.engine.internal.element.LocalVariableElementImpl;
import com.google.dart.engine.internal.element.ParameterElementImpl;
import com.google.dart.engine.internal.scope.Scope;
import com.google.dart.engine.source.Source;
import com.google.dart.engine.utilities.general.ObjectUtilities;
/**
* Instances of the class {@code VariableResolverVisitor} are used to resolve
* {@link SimpleIdentifier}s to local variables and formal parameters.
*
* @coverage dart.engine.resolver
*/
public class VariableResolverVisitor extends ScopedVisitor {
/**
* The method or function that we are currently visiting, or {@code null} if we are not inside a
* method or function.
*/
private ExecutableElement enclosingFunction;
/**
* Initialize a newly created visitor to resolve the nodes in a compilation unit.
*
* @param library the library containing the compilation unit being resolved
* @param source the source representing the compilation unit being visited
* @param typeProvider the object used to access the types from the core library
*/
public VariableResolverVisitor(Library library, Source source, TypeProvider typeProvider) {
super(library, source, typeProvider);
}
/**
* Initialize a newly created visitor to resolve the nodes in an AST node.
*
* @param definingLibrary the element for the library containing the node being visited
* @param source the source representing the compilation unit containing the node being visited
* @param typeProvider the object used to access the types from the core library
* @param nameScope the scope used to resolve identifiers in the node that will first be visited
* @param errorListener the error listener that will be informed of any errors that are found
* during resolution
*/
public VariableResolverVisitor(LibraryElement definingLibrary, Source source,
TypeProvider typeProvider, Scope nameScope, AnalysisErrorListener errorListener) {
super(definingLibrary, source, typeProvider, nameScope, errorListener);
}
/**
* Initialize a newly created visitor to resolve the nodes in a compilation unit.
*
* @param library the library containing the compilation unit being resolved
* @param source the source representing the compilation unit being visited
* @param typeProvider the object used to access the types from the core library
*/
public VariableResolverVisitor(ResolvableLibrary library, Source source, TypeProvider typeProvider) {
super(library, source, typeProvider);
}
@Override
public Void visitExportDirective(ExportDirective node) {
return null;
}
@Override
public Void visitFunctionDeclaration(FunctionDeclaration node) {
ExecutableElement outerFunction = enclosingFunction;
try {
enclosingFunction = node.getElement();
return super.visitFunctionDeclaration(node);
} finally {
enclosingFunction = outerFunction;
}
}
@Override
public Void visitFunctionExpression(FunctionExpression node) {
if (!(node.getParent() instanceof FunctionDeclaration)) {
ExecutableElement outerFunction = enclosingFunction;
try {
enclosingFunction = node.getElement();
return super.visitFunctionExpression(node);
} finally {
enclosingFunction = outerFunction;
}
} else {
return super.visitFunctionExpression(node);
}
}
@Override
public Void visitImportDirective(ImportDirective node) {
return null;
}
@Override
public Void visitMethodDeclaration(MethodDeclaration node) {
ExecutableElement outerFunction = enclosingFunction;
try {
enclosingFunction = node.getElement();
return super.visitMethodDeclaration(node);
} finally {
enclosingFunction = outerFunction;
}
}
@Override
public Void visitSimpleIdentifier(SimpleIdentifier node) {
// Ignore if already resolved - declaration or type.
if (node.getStaticElement() != null) {
return null;
}
// Ignore if qualified.
AstNode parent = node.getParent();
if (parent instanceof PrefixedIdentifier
&& ((PrefixedIdentifier) parent).getIdentifier() == node) {
return null;
}
if (parent instanceof PropertyAccess && ((PropertyAccess) parent).getPropertyName() == node) {
return null;
}
if (parent instanceof MethodInvocation && ((MethodInvocation) parent).getMethodName() == node) {
return null;
}
if (parent instanceof ConstructorName) {
return null;
}
if (parent instanceof Label) {
return null;
}
// Prepare VariableElement.
Element element = getNameScope().lookup(node, getDefiningLibrary());
if (!(element instanceof VariableElement)) {
return null;
}
// Must be local or parameter.
ElementKind kind = element.getKind();
if (kind == ElementKind.LOCAL_VARIABLE) {
node.setStaticElement(element);
if (node.inSetterContext()) {
LocalVariableElementImpl variableImpl = (LocalVariableElementImpl) element;
variableImpl.markPotentiallyMutatedInScope();
if (!ObjectUtilities.equals(element.getEnclosingElement(), enclosingFunction)) {
variableImpl.markPotentiallyMutatedInClosure();
}
}
} else if (kind == ElementKind.PARAMETER) {
node.setStaticElement(element);
if (node.inSetterContext()) {
ParameterElementImpl parameterImpl = (ParameterElementImpl) element;
parameterImpl.markPotentiallyMutatedInScope();
// If we are in some closure, check if it is not the same as where variable is declared.
if (enclosingFunction != null
&& !ObjectUtilities.equals(element.getEnclosingElement(), enclosingFunction)) {
parameterImpl.markPotentiallyMutatedInClosure();
}
}
}
return null;
}
}