/*
* Copyright 2003-2012 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.classgen;
import java.util.*;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import org.codehaus.groovy.ast.*;
import org.codehaus.groovy.ast.stmt.ReturnStatement;
import org.codehaus.groovy.ast.expr.*;
import org.codehaus.groovy.control.ErrorCollector;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.control.messages.SyntaxErrorMessage;
import org.codehaus.groovy.syntax.SyntaxException;
import org.codehaus.groovy.vmplugin.VMPluginFactory;
/**
* An Annotation visitor responsible with:
* - reading annotation metadata (@Retention, @Target, attribute types)
* - verify that an <code>AnnotationNode</code> conforms to annotation meta
* - enhancing an <code>AnnotationNode</code> AST to reflect real annotation meta
*
* @author <a href='mailto:the[dot]mindstorm[at]gmail[dot]com'>Alex Popescu</a>
*/
public class AnnotationVisitor {
private SourceUnit source;
private ErrorCollector errorCollector;
private AnnotationNode annotation;
private ClassNode reportClass;
public AnnotationVisitor(SourceUnit source, ErrorCollector errorCollector) {
this.source = source;
this.errorCollector = errorCollector;
}
public void setReportClass(ClassNode cn) {
reportClass = cn;
}
public AnnotationNode visit(AnnotationNode node) {
this.annotation = node;
this.reportClass = node.getClassNode();
if (!isValidAnnotationClass(node.getClassNode())) {
addError("class " + node.getClassNode().getName() + " is not an annotation");
return node;
}
// check if values have been passed for all annotation attributes that don't have defaults
if (!checkIfMandatoryAnnotationValuesPassed(node)) {
return node;
}
// if enum constants have been used, check if they are all valid
if (!checkIfValidEnumConstsAreUsed(node)) {
return node;
}
Map<String, Expression> attributes = node.getMembers();
for (Map.Entry<String, Expression> entry : attributes.entrySet()) {
String attrName = entry.getKey();
Expression attrExpr = transformInlineConstants(entry.getValue());
entry.setValue(attrExpr);
ClassNode attrType = getAttributeType(node, attrName);
visitExpression(attrName, attrExpr, attrType);
}
VMPluginFactory.getPlugin().configureAnnotation(node);
return this.annotation;
}
private boolean checkIfValidEnumConstsAreUsed(AnnotationNode node) {
Map<String, Expression> attributes = node.getMembers();
for (Map.Entry<String, Expression> entry : attributes.entrySet()) {
if (!validateEnumConstant(entry.getValue()))
return false;
}
return true;
}
private boolean validateEnumConstant(Expression exp) {
if (exp instanceof PropertyExpression) {
PropertyExpression pe = (PropertyExpression) exp;
String name = pe.getPropertyAsString();
if (pe.getObjectExpression() instanceof ClassExpression && name != null) {
ClassExpression ce = (ClassExpression) pe.getObjectExpression();
ClassNode type = ce.getType();
if (type.isEnum()) {
boolean ok = false;
try {
FieldNode enumField = type.getDeclaredField(name);
ok = enumField != null && enumField.getType().equals(type);
} catch(Exception ex) {
// ignore
}
if(!ok) {
addError("No enum const " + type.getName() + "." + name, pe);
return false;
}
}
}
}
return true;
}
private Expression transformInlineConstants(Expression exp) {
if (exp instanceof PropertyExpression) {
PropertyExpression pe = (PropertyExpression) exp;
if (pe.getObjectExpression() instanceof ClassExpression) {
ClassExpression ce = (ClassExpression) pe.getObjectExpression();
ClassNode type = ce.getType();
if (type.isEnum() || !type.isResolved())
return exp;
try {
Field field = type.getTypeClass().getField(pe.getPropertyAsString());
if (field != null && Modifier.isStatic(field.getModifiers()) && Modifier.isFinal(field.getModifiers())) {
return new ConstantExpression(field.get(null));
}
} catch(Exception e) {
// ignore, leave property expression in place and we'll report later
}
}
} else if (exp instanceof ListExpression) {
ListExpression le = (ListExpression) exp;
ListExpression result = new ListExpression();
for (Expression e : le.getExpressions()) {
result.addExpression(transformInlineConstants(e));
}
return result;
}
return exp;
}
private boolean checkIfMandatoryAnnotationValuesPassed(AnnotationNode node) {
boolean ok = true;
Map attributes = node.getMembers();
ClassNode classNode = node.getClassNode();
for (MethodNode mn : classNode.getMethods()) {
String methodName = mn.getName();
// if the annotation attribute has a default, getCode() returns a ReturnStatement with the default value
if (mn.getCode() == null && !attributes.containsKey(methodName)) {
addError("No explicit/default value found for annotation attribute '" + methodName + "'", node);
ok = false;
}
}
return ok;
}
private ClassNode getAttributeType(AnnotationNode node, String attrName) {
ClassNode classNode = node.getClassNode();
List methods = classNode.getMethods(attrName);
// if size is >1, then the method was overwritten or something, we ignore that
// if it is an error, we have to test it at another place. But size==0 is
// an error, because it means that no such attribute exists.
if (methods.size() == 0) {
addError("'" + attrName + "'is not part of the annotation " + classNode, node);
return ClassHelper.OBJECT_TYPE;
}
MethodNode method = (MethodNode) methods.get(0);
return method.getReturnType();
}
private boolean isValidAnnotationClass(ClassNode node) {
return node.implementsInterface(ClassHelper.Annotation_TYPE);
}
protected void visitExpression(String attrName, Expression attrExp, ClassNode attrType) {
if (attrType.isArray()) {
// check needed as @Test(attr = {"elem"}) passes through the parser
if (attrExp instanceof ListExpression) {
ListExpression le = (ListExpression) attrExp;
visitListExpression(attrName, le, attrType.getComponentType());
} else if (attrExp instanceof ClosureExpression) {
addError("Annotation list attributes must use Groovy notation [el1, el2]", attrExp);
} else {
// treat like a singleton list as per Java
ListExpression listExp = new ListExpression();
listExp.addExpression(attrExp);
if (annotation != null) {
annotation.setMember(attrName, listExp);
}
visitExpression(attrName, listExp, attrType);
}
} else if (ClassHelper.isPrimitiveType(attrType)) {
visitConstantExpression(attrName, getConstantExpression(attrExp, attrType), ClassHelper.getWrapper(attrType));
} else if (ClassHelper.STRING_TYPE.equals(attrType)) {
visitConstantExpression(attrName, getConstantExpression(attrExp, attrType), ClassHelper.STRING_TYPE);
} else if (ClassHelper.CLASS_Type.equals(attrType)) {
if (!(attrExp instanceof ClassExpression || attrExp instanceof ClosureExpression)) {
addError("Only classes and closures can be used for attribute '" + attrName + "'", attrExp);
}
} else if (attrType.isDerivedFrom(ClassHelper.Enum_Type)) {
if (attrExp instanceof PropertyExpression) {
visitEnumExpression(attrName, (PropertyExpression) attrExp, attrType);
} else {
addError("Expected enum value for attribute " + attrName, attrExp);
}
} else if (isValidAnnotationClass(attrType)) {
if (attrExp instanceof AnnotationConstantExpression) {
visitAnnotationExpression(attrName, (AnnotationConstantExpression) attrExp, attrType);
} else {
addError("Expected annotation of type '" + attrType.getName() + "' for attribute " + attrName, attrExp);
}
} else {
addError("Unexpected type " + attrType.getName(), attrExp);
}
}
public void checkReturnType(ClassNode attrType, ASTNode node) {
if (attrType.isArray()) {
checkReturnType(attrType.getComponentType(), node);
} else if (ClassHelper.isPrimitiveType(attrType)) {
return;
} else if (ClassHelper.STRING_TYPE.equals(attrType)) {
return;
} else if (ClassHelper.CLASS_Type.equals(attrType)) {
return;
} else if (attrType.isDerivedFrom(ClassHelper.Enum_Type)) {
return;
} else if (isValidAnnotationClass(attrType)) {
return;
} else {
addError("Unexpected return type " + attrType.getName(), node);
}
}
private ConstantExpression getConstantExpression(Expression exp, ClassNode attrType) {
if (exp instanceof ConstantExpression) {
return (ConstantExpression) exp;
}
String base = "Expected '" + exp.getText() + "' to be an inline constant of type " + attrType.getName();
if (exp instanceof PropertyExpression) {
addError(base + " not a property expression", exp);
} else if (exp instanceof VariableExpression && ((VariableExpression)exp).getAccessedVariable() instanceof FieldNode) {
addError(base + " not a field expression", exp);
} else {
addError(base, exp);
}
return ConstantExpression.EMPTY_EXPRESSION;
}
/**
* @param attrName the name
* @param expression the expression
* @param attrType the type
*/
protected void visitAnnotationExpression(String attrName, AnnotationConstantExpression expression, ClassNode attrType) {
AnnotationNode annotationNode = (AnnotationNode) expression.getValue();
AnnotationVisitor visitor = new AnnotationVisitor(this.source, this.errorCollector);
// TODO track Deprecated usage and give a warning?
visitor.visit(annotationNode);
}
protected void visitListExpression(String attrName, ListExpression listExpr, ClassNode elementType) {
for (Expression expression : listExpr.getExpressions()) {
visitExpression(attrName, expression, elementType);
}
}
protected void visitConstantExpression(String attrName, ConstantExpression constExpr, ClassNode attrType) {
ClassNode constType = constExpr.getType();
ClassNode wrapperType = ClassHelper.getWrapper(constType);
if (!hasCompatibleType(attrType, wrapperType)) {
addError("Attribute '" + attrName + "' should have type '" + attrType.getName()
+ "'; but found type '" + constType.getName() + "'", constExpr);
}
}
private boolean hasCompatibleType(ClassNode attrType, ClassNode wrapperType) {
return wrapperType.isDerivedFrom(ClassHelper.getWrapper(attrType));
}
protected void visitEnumExpression(String attrName, PropertyExpression propExpr, ClassNode attrType) {
if (!propExpr.getObjectExpression().getType().isDerivedFrom(attrType)) {
addError("Attribute '" + attrName + "' should have type '" + attrType.getName() + "' (Enum), but found "
+ propExpr.getObjectExpression().getType().getName(),
propExpr);
}
}
protected void addError(String msg) {
addError(msg, this.annotation);
}
protected void addError(String msg, ASTNode expr) {
this.errorCollector.addErrorAndContinue(
new SyntaxErrorMessage(new SyntaxException(msg + " in @" + this.reportClass.getName() + '\n', expr.getLineNumber(), expr.getColumnNumber(), expr.getLastLineNumber(), expr.getLastColumnNumber()), this.source)
);
}
public void checkCircularReference(ClassNode searchClass, ClassNode attrType, Expression startExp) {
if (!isValidAnnotationClass(attrType)) return;
if (!(startExp instanceof AnnotationConstantExpression)) {
addError("Found '" + startExp.getText() + "' when expecting an Annotation Constant", startExp);
return;
}
AnnotationConstantExpression ace = (AnnotationConstantExpression) startExp;
AnnotationNode annotationNode = (AnnotationNode) ace.getValue();
if (annotationNode.getClassNode().equals(searchClass)) {
addError("Circular reference discovered in " + searchClass.getName(), startExp);
return;
}
ClassNode cn = annotationNode.getClassNode();
for (MethodNode method : cn.getMethods()) {
if (method.getReturnType().equals(searchClass)) {
addError("Circular reference discovered in " + cn.getName(), startExp);
}
ReturnStatement code = (ReturnStatement) method.getCode();
if (code == null) continue;
checkCircularReference(searchClass, method.getReturnType(), code.getExpression());
}
}
}