/*
* Copyright 2008-2010 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.*;
import org.codehaus.groovy.ast.expr.ArrayExpression;
import org.codehaus.groovy.ast.expr.ConstantExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.expr.VariableExpression;
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 org.objectweb.asm.Opcodes;
import java.util.Arrays;
/**
* Handles generation of code for the {@code @}Synchronized annotation.
*
* @author Paul King
*/
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
public class SynchronizedASTTransformation implements ASTTransformation, Opcodes {
private static final Class MY_CLASS = Synchronized.class;
private static final ClassNode MY_TYPE = ClassHelper.make(MY_CLASS);
private static final String MY_TYPE_NAME = "@" + MY_TYPE.getNameWithoutPackage();
public void visit(ASTNode[] nodes, SourceUnit source) {
if (nodes.length != 2 || !(nodes[0] instanceof AnnotationNode) || !(nodes[1] instanceof AnnotatedNode)) {
throw new RuntimeException("Internal error: expecting [AnnotationNode, AnnotatedNode] but got: " + Arrays.asList(nodes));
}
AnnotatedNode parent = (AnnotatedNode) nodes[1];
AnnotationNode node = (AnnotationNode) nodes[0];
if (!MY_TYPE.equals(node.getClassNode())) return;
Expression valueExpr = node.getMember("value");
String value = null;
if (valueExpr instanceof ConstantExpression) {
ConstantExpression ce = (ConstantExpression) valueExpr;
Object valueObject = ce.getValue();
if (valueObject != null) value = valueObject.toString();
}
if (parent instanceof MethodNode) {
MethodNode mNode = (MethodNode) parent;
ClassNode cNode = mNode.getDeclaringClass();
String lockExpr = determineLock(value, cNode, mNode.isStatic());
Statement origCode = mNode.getCode();
Statement newCode = new SynchronizedStatement(new VariableExpression(lockExpr), origCode);
mNode.setCode(newCode);
}
}
private String determineLock(String value, ClassNode cNode, boolean isStatic) {
if (value != null && value.length() > 0 && !value.equalsIgnoreCase("$lock")) {
if (cNode.getDeclaredField(value) == null) {
throw new RuntimeException("Error during " + MY_TYPE_NAME + " processing: lock field with name '" + value + "' not found in class " + cNode.getName());
}
if (cNode.getDeclaredField(value).isStatic() != isStatic) {
throw new RuntimeException("Error during " + MY_TYPE_NAME + " processing: lock field with name '" + value + "' should " + (isStatic ? "" : "not ") + "be static");
}
return value;
}
if (isStatic) {
FieldNode field = cNode.getDeclaredField("$LOCK");
if (field == null) {
int visibility = ACC_PRIVATE | ACC_STATIC | ACC_FINAL;
cNode.addField("$LOCK", visibility, ClassHelper.OBJECT_TYPE, zeroLengthObjectArray());
} else if (!field.isStatic()) {
throw new RuntimeException("Error during " + MY_TYPE_NAME + " processing: $LOCK field must be static");
}
return "$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()) {
throw new RuntimeException("Error during " + MY_TYPE_NAME + " processing: $lock field must not be static");
}
return "$lock";
}
private Expression zeroLengthObjectArray() {
return new ArrayExpression(ClassHelper.OBJECT_TYPE, null, Arrays.asList((Expression)new ConstantExpression(0)));
}
}