/*
* Copyright 2008-2014 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.transform.Synchronized;
import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.AnnotatedNode;
import org.codehaus.groovy.ast.AnnotationNode;
import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.FieldNode;
import org.codehaus.groovy.ast.MethodNode;
import org.codehaus.groovy.ast.expr.ArrayExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.stmt.Statement;
import org.codehaus.groovy.ast.stmt.SynchronizedStatement;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;
import java.util.Arrays;
import static org.codehaus.groovy.ast.ClassHelper.make;
import static org.codehaus.groovy.ast.tools.GeneralUtils.constX;
import static org.codehaus.groovy.ast.tools.GeneralUtils.varX;
/**
* Handles generation of code for the {@code @Synchronized} annotation.
*
* @author Paul King
*/
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
public class SynchronizedASTTransformation extends AbstractASTTransformation {
private static final Class MY_CLASS = Synchronized.class;
private static final ClassNode MY_TYPE = make(MY_CLASS);
private static final String MY_TYPE_NAME = "@" + MY_TYPE.getNameWithoutPackage();
public void visit(ASTNode[] nodes, SourceUnit source) {
init(nodes, source);
AnnotatedNode parent = (AnnotatedNode) nodes[1];
AnnotationNode node = (AnnotationNode) nodes[0];
if (!MY_TYPE.equals(node.getClassNode())) return;
String value = getMemberStringValue(node, "value");
if (parent instanceof MethodNode) {
MethodNode mNode = (MethodNode) parent;
if (mNode.isAbstract()) {
addError("Error during " + MY_TYPE_NAME + " processing: annotation not allowed on abstract method '" + mNode.getName() + "'", mNode);
return;
}
ClassNode cNode = mNode.getDeclaringClass();
String lockExpr = determineLock(value, cNode, mNode);
if (lockExpr == null) return;
Statement origCode = mNode.getCode();
Statement newCode = new SynchronizedStatement(varX(lockExpr), origCode);
mNode.setCode(newCode);
}
}
private String determineLock(String value, ClassNode cNode, MethodNode mNode) {
boolean isStatic = mNode.isStatic();
if (value != null && value.length() > 0 && !value.equalsIgnoreCase("$lock")) {
if (cNode.getDeclaredField(value) == null) {
addError("Error during " + MY_TYPE_NAME + " processing: lock field with name '" + value + "' not found in class " + cNode.getName(), mNode);
return null;
}
FieldNode field = cNode.getDeclaredField(value);
if (isStatic && !field.isStatic()) {
addError("Error during " + MY_TYPE_NAME + " processing: lock field with name '" + value + "' must be static for static method '" + mNode.getName() + "'", field);
return null;
}
return value;
}
if (isStatic) {
FieldNode field = cNode.getDeclaredField("$LOCK");
if (field == null) {
int visibility = ACC_PRIVATE | ACC_STATIC | ACC_FINAL;
cNode.addField("$LOCK", visibility, ClassHelper.OBJECT_TYPE, zeroLengthObjectArray());
} else if (!field.isStatic()) {
addError("Error during " + MY_TYPE_NAME + " processing: $LOCK field must be static", field);
}
return "$LOCK";
}
FieldNode field = cNode.getDeclaredField("$lock");
if (field == null) {
int visibility = ACC_PRIVATE | ACC_FINAL;
cNode.addField("$lock", visibility, ClassHelper.OBJECT_TYPE, zeroLengthObjectArray());
} else if (field.isStatic()) {
addError("Error during " + MY_TYPE_NAME + " processing: $lock field must not be static", field);
}
return "$lock";
}
private Expression zeroLengthObjectArray() {
return new ArrayExpression(ClassHelper.OBJECT_TYPE, null, Arrays.asList((Expression)constX(0)));
}
}