/*
* 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.lang.GroovyObject;
import org.codehaus.groovy.GroovyBugError;
import org.codehaus.groovy.ast.*;
import org.codehaus.groovy.ast.expr.*;
import org.codehaus.groovy.ast.stmt.ExpressionStatement;
import org.codehaus.groovy.ast.stmt.ReturnStatement;
import org.codehaus.groovy.classgen.Verifier;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.control.messages.SyntaxErrorMessage;
import org.codehaus.groovy.syntax.SyntaxException;
import org.codehaus.groovy.syntax.Token;
import org.codehaus.groovy.syntax.Types;
import org.objectweb.asm.Opcodes;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Set;
/**
* Handles generation of code for the <code>@Delegate</code> annotation
*
* @author Alex Tkachman
* @author Guillaume Laforge
* @author Paul King
*/
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
public class DelegateASTTransformation implements ASTTransformation, Opcodes {
private static final ClassNode DEPRECATED_TYPE = ClassHelper.make(Deprecated.class);
private static final ClassNode GROOVYOBJECT_TYPE = ClassHelper.make(GroovyObject.class);
public void visit(ASTNode[] nodes, SourceUnit source) {
if (nodes.length != 2 || !(nodes[0] instanceof AnnotationNode) || !(nodes[1] instanceof AnnotatedNode)) {
throw new GroovyBugError("Internal error: expecting [AnnotationNode, AnnotatedNode] but got: " + Arrays.asList(nodes));
}
AnnotatedNode parent = (AnnotatedNode) nodes[1];
AnnotationNode node = (AnnotationNode) nodes[0];
if (parent instanceof FieldNode) {
FieldNode fieldNode = (FieldNode) parent;
final ClassNode type = fieldNode.getType();
final ClassNode owner = fieldNode.getOwner();
if (type.equals(ClassHelper.OBJECT_TYPE) || type.equals(GROOVYOBJECT_TYPE)) {
addError("@Delegate field '" + fieldNode.getName() + "' has an inappropriate type: " + type.getName() +
". Please add an explicit type but not java.lang.Object or groovy.lang.GroovyObject.", parent, source);
return;
}
if (type.equals(owner)) {
addError("@Delegate field '" + fieldNode.getName() + "' has an inappropriate type: " + type.getName() +
". Delegation to own type not supported. Please use a different type.", parent, source);
return;
}
final List<MethodNode> fieldMethods = getAllMethods(type);
for (ClassNode next : type.getAllInterfaces()) {
fieldMethods.addAll(getAllMethods(next));
}
final Expression deprecatedElement = node.getMember("deprecated");
final boolean deprecated = hasBooleanValue(deprecatedElement, true);
final List<MethodNode> ownerMethods = getAllMethods(owner);
for (MethodNode mn : fieldMethods) {
addDelegateMethod(fieldNode, owner, ownerMethods, mn, deprecated);
}
for (PropertyNode prop : type.getProperties()) {
if (prop.isStatic() || !prop.isPublic())
continue;
String name = prop.getName();
addGetterIfNeeded(fieldNode, owner, prop, name);
addSetterIfNeeded(fieldNode, owner, prop, name);
}
final Expression interfacesElement = node.getMember("interfaces");
if (hasBooleanValue(interfacesElement, false)) return;
final Set<ClassNode> allInterfaces = type.getAllInterfaces();
final Set<ClassNode> ownerIfaces = owner.getAllInterfaces();
for (ClassNode iface : allInterfaces) {
if (Modifier.isPublic(iface.getModifiers()) && !ownerIfaces.contains(iface)) {
final ClassNode[] ifaces = owner.getInterfaces();
final ClassNode[] newIfaces = new ClassNode[ifaces.length + 1];
System.arraycopy(ifaces, 0, newIfaces, 0, ifaces.length);
newIfaces[ifaces.length] = iface;
owner.setInterfaces(newIfaces);
}
}
}
}
private List<MethodNode> getAllMethods(ClassNode type) {
ClassNode node = type;
List<MethodNode> result = new ArrayList<MethodNode>();
while (node != null) {
result.addAll(node.getMethods());
node = node.getSuperClass();
}
return result;
}
private boolean hasBooleanValue(Expression expression, boolean bool) {
return expression instanceof ConstantExpression && ((ConstantExpression) expression).getValue().equals(bool);
}
private void addSetterIfNeeded(FieldNode fieldNode, ClassNode owner, PropertyNode prop, String name) {
String setterName = "set" + Verifier.capitalize(name);
if ((prop.getModifiers() & ACC_FINAL) == 0 && owner.getSetterMethod(setterName) == null) {
owner.addMethod(setterName,
ACC_PUBLIC,
ClassHelper.VOID_TYPE,
new Parameter[]{new Parameter(nonGeneric(prop.getType()), "value")},
null,
new ExpressionStatement(
new BinaryExpression(
new PropertyExpression(
new VariableExpression(fieldNode),
name),
Token.newSymbol(Types.EQUAL, -1, -1),
new VariableExpression("value"))));
}
}
private void addGetterIfNeeded(FieldNode fieldNode, ClassNode owner, PropertyNode prop, String name) {
String getterName = "get" + Verifier.capitalize(name);
if (owner.getGetterMethod(getterName) == null) {
owner.addMethod(getterName,
ACC_PUBLIC,
nonGeneric(prop.getType()),
Parameter.EMPTY_ARRAY,
null,
new ReturnStatement(
new PropertyExpression(
new VariableExpression(fieldNode),
name)));
}
}
private void addDelegateMethod(FieldNode fieldNode, ClassNode owner, List<MethodNode> ownMethods, MethodNode candidate, boolean deprecated) {
if (!candidate.isPublic() || candidate.isStatic() || 0 != (candidate.getModifiers () & Opcodes.ACC_SYNTHETIC))
return;
if (!candidate.getAnnotations(DEPRECATED_TYPE).isEmpty() && !deprecated)
return;
// ignore methods from GroovyObject
for (MethodNode mn : GROOVYOBJECT_TYPE.getMethods()) {
if (mn.getTypeDescriptor().equals(candidate.getTypeDescriptor())) {
return;
}
}
// ignore methods already in owner
for (MethodNode mn : owner.getMethods()) {
if (mn.getTypeDescriptor().equals(candidate.getTypeDescriptor())) {
return;
}
}
// give precedence to methods of self (but not abstract or static superclass methods)
// also allows abstract or static self methods to be selected for overriding but they are ignored later
MethodNode existingNode = null;
for (MethodNode mn : ownMethods) {
if (mn.getTypeDescriptor().equals(candidate.getTypeDescriptor()) && !mn.isAbstract() && !mn.isStatic()) {
existingNode = mn;
break;
}
}
if (existingNode == null || existingNode.getCode() == null) {
final ArgumentListExpression args = new ArgumentListExpression();
final Parameter[] params = candidate.getParameters();
final Parameter[] newParams = new Parameter[params.length];
for (int i = 0; i < newParams.length; i++) {
Parameter newParam = new Parameter(nonGeneric(params[i].getType()), params[i].getName());
newParam.setInitialExpression(params[i].getInitialExpression());
newParams[i] = newParam;
args.addExpression(new VariableExpression(newParam));
}
// addMethod will ignore attempts to override abstract or static methods with same signature on self
MethodNode newMethod = owner.addMethod(candidate.getName(),
candidate.getModifiers() & (~ACC_ABSTRACT) & (~ACC_NATIVE),
nonGeneric(candidate.getReturnType()),
newParams,
candidate.getExceptions(),
new ExpressionStatement(
new MethodCallExpression(
new VariableExpression(fieldNode),
candidate.getName(),
args)));
newMethod.setGenericsTypes(candidate.getGenericsTypes());
}
}
private ClassNode nonGeneric(ClassNode type) {
if (type.isUsingGenerics()) {
final ClassNode nonGen = ClassHelper.makeWithoutCaching(type.getName());
nonGen.setRedirect(type);
nonGen.setGenericsTypes(null);
nonGen.setUsingGenerics(false);
return nonGen;
} else {
return type;
}
}
public void addError(String msg, ASTNode expr, SourceUnit source) {
int line = expr.getLineNumber();
int col = expr.getColumnNumber();
source.getErrorCollector().addErrorAndContinue(
new SyntaxErrorMessage(new SyntaxException(msg + '\n', line, col), source)
);
}
}