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Groovy: A powerful, dynamic language for the JVM
/*
* Copyright 2008-2009 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* 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 org.codehaus.groovy.transform;
import groovy.lang.Newify;
import org.codehaus.groovy.ast.*;
import org.codehaus.groovy.ast.expr.*;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;
import java.util.HashSet;
import java.util.List;
import java.util.Arrays;
/**
* Handles generation of code for the @Newify annotation.
*
* @author Paul King
*/
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
public class NewifyASTTransformation extends ClassCodeExpressionTransformer implements ASTTransformation {
private static final ClassNode MY_TYPE = new ClassNode(Newify.class);
private static final String MY_NAME = MY_TYPE.getNameWithoutPackage();
private SourceUnit source;
private ListExpression classesToNewify;
private boolean auto;
public void visit(ASTNode[] nodes, SourceUnit source) {
this.source = source;
if (nodes.length != 2 || !(nodes[0] instanceof AnnotationNode) || !(nodes[1] instanceof AnnotatedNode)) {
internalError("Expecting [AnnotationNode, AnnotatedClass] but got: " + Arrays.asList(nodes));
}
AnnotatedNode parent = (AnnotatedNode) nodes[1];
AnnotationNode node = (AnnotationNode) nodes[0];
if (!MY_TYPE.equals(node.getClassNode())) {
internalError("Transformation called from wrong annotation: " + node.getClassNode().getName());
}
boolean autoFlag = determineAutoFlag(node.getMember("auto"));
ListExpression list = determineClassesToNewify(node.getMember("value"));
if (parent instanceof ClassNode) {
newifyClass(parent, autoFlag, list);
} else if (parent instanceof MethodNode || parent instanceof FieldNode) {
newifyMethodOrField(parent, autoFlag, list);
}
}
private boolean determineAutoFlag(Expression autoExpr) {
return !(autoExpr instanceof ConstantExpression && ((ConstantExpression) autoExpr).getValue().equals(false));
}
private ListExpression determineClassesToNewify(Expression expr) {
ListExpression list = new ListExpression();
if (expr instanceof ClassExpression) {
list.addExpression(expr);
} else if (expr instanceof ListExpression) {
list = (ListExpression) expr;
final List expressions = list.getExpressions();
for (Expression ex : expressions) {
if (!(ex instanceof ClassExpression)) {
throw new RuntimeException("Error during @" + MY_NAME
+ " processing. Annotation parameter must be a list of classes.");
}
}
checkDuplicateNameClashes(list);
}
return list;
}
public Expression transform(Expression expr) {
if (expr == null) return null;
if (expr instanceof MethodCallExpression) {
MethodCallExpression mce = (MethodCallExpression) expr;
Expression args = transform(mce.getArguments());
Expression method = transform(mce.getMethod());
Expression object = transform(mce.getObjectExpression());
if (isNewifyCandidate(mce)) {
return transformMethodCall(mce, args);
}
return new MethodCallExpression(object, method, args);
} else if (expr instanceof PropertyExpression) {
PropertyExpression pe = (PropertyExpression) expr;
pe.setObjectExpression(transform(pe.getObjectExpression()));
return pe;
}
return expr.transformExpression(this);
}
private void newifyClass(AnnotatedNode parent, boolean autoFlag, ListExpression list) {
ClassNode cNode = (ClassNode) parent;
String cName = cNode.getName();
if (cNode.isInterface()) {
throw new RuntimeException("Error processing interface '" + cName + "'. @"
+ MY_NAME + " not allowed for interfaces.");
}
classesToNewify = list;
auto = autoFlag;
super.visitClass(cNode);
}
private void newifyMethodOrField(AnnotatedNode parent, boolean autoFlag, ListExpression list) {
final ListExpression oldClassesToNewify = classesToNewify;
final boolean oldAuto = auto;
checkClassLevelClashes(list);
checkAutoClash(autoFlag);
classesToNewify = list;
auto = autoFlag;
if (parent instanceof FieldNode) {
super.visitField((FieldNode) parent);
} else {
super.visitMethod((MethodNode) parent);
}
classesToNewify = oldClassesToNewify;
auto = oldAuto;
}
private void checkDuplicateNameClashes(ListExpression list) {
final HashSet seen = new HashSet();
final List classes = list.getExpressions();
for (ClassExpression ce : classes) {
final String name = ce.getType().getNameWithoutPackage();
if (seen.contains(name)) {
throw new RuntimeException("Duplicate name '" + name + "' found during @"
+ MY_NAME + " processing.");
}
seen.add(name);
}
}
private void checkAutoClash(boolean autoFlag) {
if (auto && !autoFlag) {
throw new RuntimeException("Error during @" + MY_NAME +
" processing. The 'auto' flag can't be false at method/constructor/field level if it is true at the class level.");
}
}
private void checkClassLevelClashes(ListExpression list) {
final List classes = list.getExpressions();
for (ClassExpression ce : classes) {
final String name = ce.getType().getNameWithoutPackage();
if (findClassWithMatchingBasename(name)) {
throw new RuntimeException("Error during @" + MY_NAME + " processing. Class '" + name
+ "' can't appear at method/constructor/field level if it already appears at the class level.");
}
}
}
private boolean findClassWithMatchingBasename(String nameWithoutPackage) {
if (classesToNewify == null) return false;
final List classes = classesToNewify.getExpressions();
for (ClassExpression ce : classes) {
if (ce.getType().getNameWithoutPackage().equals(nameWithoutPackage)) {
return true;
}
}
return false;
}
private boolean isNewifyCandidate(MethodCallExpression mce) {
return mce.getObjectExpression() == VariableExpression.THIS_EXPRESSION
|| (auto && isNewMethodStyle(mce));
}
private boolean isNewMethodStyle(MethodCallExpression mce) {
final Expression obj = mce.getObjectExpression();
final Expression meth = mce.getMethod();
return (obj instanceof ClassExpression && meth instanceof ConstantExpression
&& ((ConstantExpression) meth).getValue().equals("new"));
}
private Expression transformMethodCall(MethodCallExpression mce, Expression args) {
ClassNode classType;
if (isNewMethodStyle(mce)) {
classType = mce.getObjectExpression().getType();
} else {
classType = findMatchingCandidateClass(mce);
}
if (classType != null) {
return new ConstructorCallExpression(classType, args);
}
// set the args as they might have gotten Newify transformed GROOVY-3491
mce.setArguments(args);
return mce;
}
private ClassNode findMatchingCandidateClass(MethodCallExpression mce) {
if (classesToNewify == null) return null;
List classes = classesToNewify.getExpressions();
for (ClassExpression ce : classes) {
final ClassNode type = ce.getType();
if (type.getNameWithoutPackage().equals(mce.getMethodAsString())) {
return type;
}
}
return null;
}
private void internalError(String message) {
throw new RuntimeException("Internal error: " + message);
}
protected SourceUnit getSourceUnit() {
return source;
}
}