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Groovy: A powerful, dynamic language for the JVM
/*
* Copyright 2008-2013 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.MetaClass;
import groovy.lang.MissingPropertyException;
import groovy.lang.ReadOnlyPropertyException;
import groovy.transform.Immutable;
import org.codehaus.groovy.ast.*;
import org.codehaus.groovy.ast.expr.*;
import org.codehaus.groovy.ast.stmt.BlockStatement;
import org.codehaus.groovy.ast.stmt.EmptyStatement;
import org.codehaus.groovy.ast.stmt.ExpressionStatement;
import org.codehaus.groovy.ast.stmt.IfStatement;
import org.codehaus.groovy.ast.stmt.Statement;
import org.codehaus.groovy.ast.stmt.ThrowStatement;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.runtime.DefaultGroovyMethods;
import org.codehaus.groovy.runtime.InvokerHelper;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import static org.codehaus.groovy.transform.AbstractASTTransformUtil.*;
import static org.codehaus.groovy.transform.EqualsAndHashCodeASTTransformation.createEquals;
import static org.codehaus.groovy.transform.EqualsAndHashCodeASTTransformation.createHashCode;
import static org.codehaus.groovy.transform.ToStringASTTransformation.createToString;
/**
* Handles generation of code for the @Immutable annotation.
*
* @author Paul King
* @author Andre Steingress
*/
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
public class ImmutableASTTransformation extends AbstractASTTransformation {
/*
Currently leaving BigInteger and BigDecimal in list but see:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6348370
Also, Color is not final so while not normally used with child
classes, it isn't strictly immutable. Use at your own risk.
This list can by extended by providing "known immutable" classes
via Immutable.knownImmutableClasses
*/
private static List immutableList = Arrays.asList(
"java.lang.Boolean",
"java.lang.Byte",
"java.lang.Character",
"java.lang.Double",
"java.lang.Float",
"java.lang.Integer",
"java.lang.Long",
"java.lang.Short",
"java.lang.String",
"java.math.BigInteger",
"java.math.BigDecimal",
"java.awt.Color",
"java.net.URI",
"java.util.UUID"
);
private static final Class MY_CLASS = groovy.transform.Immutable.class;
static final ClassNode MY_TYPE = ClassHelper.make(MY_CLASS);
static final String MY_TYPE_NAME = "@" + MY_TYPE.getNameWithoutPackage();
static final String MEMBER_KNOWN_IMMUTABLE_CLASSES = "knownImmutableClasses";
static final String MEMBER_KNOWN_IMMUTABLES = "knownImmutables";
private static final ClassNode DATE_TYPE = ClassHelper.make(Date.class);
private static final ClassNode CLONEABLE_TYPE = ClassHelper.make(Cloneable.class);
private static final ClassNode COLLECTION_TYPE = ClassHelper.makeWithoutCaching(Collection.class, false);
private static final ClassNode READONLYEXCEPTION_TYPE = ClassHelper.make(ReadOnlyPropertyException.class);
private static final ClassNode DGM_TYPE = ClassHelper.make(DefaultGroovyMethods.class);
private static final ClassNode SELF_TYPE = ClassHelper.make(ImmutableASTTransformation.class);
private static final ClassNode HASHMAP_TYPE = ClassHelper.makeWithoutCaching(HashMap.class, false);
private static final ClassNode MAP_TYPE = ClassHelper.makeWithoutCaching(Map.class, false);
public void visit(ASTNode[] nodes, SourceUnit source) {
init(nodes, source);
AnnotatedNode parent = (AnnotatedNode) nodes[1];
AnnotationNode node = (AnnotationNode) nodes[0];
// temporarily have weaker check which allows for old Deprecated Annotation
// if (!MY_TYPE.equals(node.getClassNode())) return;
if (!node.getClassNode().getName().endsWith(".Immutable")) return;
List newProperties = new ArrayList();
if (parent instanceof ClassNode) {
final List knownImmutableClasses = getKnownImmutableClasses(node);
final List knownImmutables = getKnownImmutables(node);
ClassNode cNode = (ClassNode) parent;
String cName = cNode.getName();
checkNotInterface(cNode, MY_TYPE_NAME);
makeClassFinal(cNode);
final List pList = getInstanceProperties(cNode);
for (PropertyNode pNode : pList) {
adjustPropertyForImmutability(pNode, newProperties);
}
for (PropertyNode pNode : newProperties) {
cNode.getProperties().remove(pNode);
addProperty(cNode, pNode);
}
final List fList = cNode.getFields();
for (FieldNode fNode : fList) {
ensureNotPublic(cName, fNode);
}
createConstructors(cNode, knownImmutableClasses, knownImmutables);
createHashCode(cNode, true, false, false, null, null);
createEquals(cNode, false, false, false, null, null);
if (!hasAnnotation(cNode, ToStringASTTransformation.MY_TYPE)) {
createToString(cNode, false, false, null, null, false, true);
}
}
}
private void doAddConstructor(final ClassNode cNode, final ConstructorNode constructorNode) {
cNode.addConstructor(constructorNode);
// GROOVY-5814: Immutable is not compatible with @CompileStatic
Parameter argsParam = null;
for (Parameter p : constructorNode.getParameters()) {
if ("args".equals(p.getName())) {
argsParam = p;
break;
}
}
if (argsParam!=null) {
final Parameter arg = argsParam;
ClassCodeVisitorSupport variableExpressionFix = new ClassCodeVisitorSupport() {
@Override
protected SourceUnit getSourceUnit() {
return cNode.getModule().getContext();
}
@Override
public void visitVariableExpression(final VariableExpression expression) {
super.visitVariableExpression(expression);
if ("args".equals(expression.getName())) {
expression.setAccessedVariable(arg);
}
}
};
variableExpressionFix.visitConstructor(constructorNode);
}
}
private List getKnownImmutableClasses(AnnotationNode node) {
final ArrayList immutableClasses = new ArrayList();
final Expression expression = node.getMember(MEMBER_KNOWN_IMMUTABLE_CLASSES);
if (expression == null) return immutableClasses;
if (!(expression instanceof ListExpression)) {
addError("Use the Groovy list notation [el1, el2] to specify known immutable classes via \"" + MEMBER_KNOWN_IMMUTABLE_CLASSES + "\"", node);
return immutableClasses;
}
final ListExpression listExpression = (ListExpression) expression;
for (Expression listItemExpression : listExpression.getExpressions()) {
if (listItemExpression instanceof ClassExpression) {
immutableClasses.add(listItemExpression.getType().getName());
}
}
return immutableClasses;
}
private List getKnownImmutables(AnnotationNode node) {
final ArrayList immutables = new ArrayList();
final Expression expression = node.getMember(MEMBER_KNOWN_IMMUTABLES);
if (expression == null) return immutables;
if (!(expression instanceof ListExpression)) {
addError("Use the Groovy list notation [el1, el2] to specify known immutable property names via \"" + MEMBER_KNOWN_IMMUTABLES + "\"", node);
return immutables;
}
final ListExpression listExpression = (ListExpression) expression;
for (Expression listItemExpression : listExpression.getExpressions()) {
if (listItemExpression instanceof ConstantExpression) {
immutables.add((String) ((ConstantExpression) listItemExpression).getValue());
}
}
return immutables;
}
private void makeClassFinal(ClassNode cNode) {
if ((cNode.getModifiers() & ACC_FINAL) == 0) {
cNode.setModifiers(cNode.getModifiers() | ACC_FINAL);
}
}
private void createConstructors(ClassNode cNode, List knownImmutableClasses, List knownImmutables) {
if (!validateConstructors(cNode)) return;
List list = getInstanceProperties(cNode);
boolean specialHashMapCase = list.size() == 1 && list.get(0).getField().getType().equals(HASHMAP_TYPE);
if (specialHashMapCase) {
createConstructorMapSpecial(cNode, list);
} else {
createConstructorMap(cNode, list, knownImmutableClasses, knownImmutables);
createConstructorOrdered(cNode, list);
}
}
private void createConstructorOrdered(ClassNode cNode, List list) {
final MapExpression argMap = new MapExpression();
final Parameter[] orderedParams = new Parameter[list.size()];
int index = 0;
for (PropertyNode pNode : list) {
Parameter param = new Parameter(pNode.getField().getType(), pNode.getField().getName());
orderedParams[index++] = param;
argMap.addMapEntryExpression(new ConstantExpression(pNode.getName()), new VariableExpression(pNode.getName()));
}
final BlockStatement orderedBody = new BlockStatement();
orderedBody.addStatement(new ExpressionStatement(
new ConstructorCallExpression(ClassNode.THIS, new ArgumentListExpression(new CastExpression(HASHMAP_TYPE, argMap)))
));
doAddConstructor(cNode,new ConstructorNode(ACC_PUBLIC, orderedParams, ClassNode.EMPTY_ARRAY, orderedBody));
}
private Statement createGetterBodyDefault(FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
return new ExpressionStatement(fieldExpr);
}
private Expression cloneCollectionExpr(Expression fieldExpr) {
return new StaticMethodCallExpression(DGM_TYPE, "asImmutable", fieldExpr);
}
private Expression cloneArrayOrCloneableExpr(Expression fieldExpr) {
return new MethodCallExpression(fieldExpr, "clone", MethodCallExpression.NO_ARGUMENTS);
}
private void createConstructorMapSpecial(ClassNode cNode, List list) {
final BlockStatement body = new BlockStatement();
body.addStatement(createConstructorStatementMapSpecial(list.get(0).getField()));
createConstructorMapCommon(cNode, body);
}
private void createConstructorMap(ClassNode cNode, List list, List knownImmutableClasses, List knownImmutables) {
final BlockStatement body = new BlockStatement();
for (PropertyNode pNode : list) {
body.addStatement(createConstructorStatement(cNode, pNode, knownImmutableClasses, knownImmutables));
}
// check for missing properties
Expression checkArgs = new ArgumentListExpression(new VariableExpression("this"), new VariableExpression("args"));
body.addStatement(new ExpressionStatement(new StaticMethodCallExpression(SELF_TYPE, "checkPropNames", checkArgs)));
createConstructorMapCommon(cNode, body);
}
private void createConstructorMapCommon(ClassNode cNode, BlockStatement body) {
final List fList = cNode.getFields();
for (FieldNode fNode : fList) {
if (fNode.isPublic()) continue; // public fields will be rejected elsewhere
if (cNode.getProperty(fNode.getName()) != null) continue; // a property
if (fNode.isFinal() && fNode.isStatic()) continue;
if (fNode.getName().contains("$")) continue; // internal field
if (fNode.isFinal() && fNode.getInitialExpression() != null)
body.addStatement(checkFinalArgNotOverridden(cNode, fNode));
body.addStatement(createConstructorStatementDefault(fNode));
}
final Parameter[] params = new Parameter[]{new Parameter(HASHMAP_TYPE, "args")};
doAddConstructor(cNode, new ConstructorNode(ACC_PUBLIC, params, ClassNode.EMPTY_ARRAY, new IfStatement(
equalsNullExpr(new VariableExpression("args")),
new EmptyStatement(),
body)));
}
private Statement checkFinalArgNotOverridden(ClassNode cNode, FieldNode fNode) {
final String name = fNode.getName();
Expression value = findArg(name);
return new IfStatement(
equalsNullExpr(value),
new EmptyStatement(),
new ThrowStatement(new ConstructorCallExpression(READONLYEXCEPTION_TYPE,
new ArgumentListExpression(new ConstantExpression(name),
new ConstantExpression(cNode.getName())))));
}
private Statement createConstructorStatementMapSpecial(FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
Expression initExpr = fNode.getInitialValueExpression();
if (initExpr == null) initExpr = new ConstantExpression(null);
Expression namedArgs = findArg(fNode.getName());
Expression baseArgs = new VariableExpression("args");
return new IfStatement(
equalsNullExpr(baseArgs),
new IfStatement(
equalsNullExpr(initExpr),
new EmptyStatement(),
assignStatement(fieldExpr, cloneCollectionExpr(initExpr))),
new IfStatement(
equalsNullExpr(namedArgs),
new IfStatement(
isTrueExpr(new MethodCallExpression(baseArgs, "containsKey", new ConstantExpression(fNode.getName()))),
assignStatement(fieldExpr, namedArgs),
assignStatement(fieldExpr, cloneCollectionExpr(baseArgs))),
new IfStatement(
isOneExpr(new MethodCallExpression(baseArgs, "size", MethodCallExpression.NO_ARGUMENTS)),
assignStatement(fieldExpr, cloneCollectionExpr(namedArgs)),
assignStatement(fieldExpr, cloneCollectionExpr(baseArgs)))
)
);
}
private void ensureNotPublic(String cNode, FieldNode fNode) {
String fName = fNode.getName();
// TODO: do we need to lock down things like: $ownClass
if (fNode.isPublic() && !fName.contains("$") && !(fNode.isStatic() && fNode.isFinal())) {
addError("Public field '" + fName + "' not allowed for " + MY_TYPE_NAME + " class '" + cNode + "'.", fNode);
}
}
private void addProperty(ClassNode cNode, PropertyNode pNode) {
final FieldNode fn = pNode.getField();
cNode.getFields().remove(fn);
cNode.addProperty(pNode.getName(), pNode.getModifiers() | ACC_FINAL, pNode.getType(),
pNode.getInitialExpression(), pNode.getGetterBlock(), pNode.getSetterBlock());
final FieldNode newfn = cNode.getField(fn.getName());
cNode.getFields().remove(newfn);
cNode.addField(fn);
}
private boolean validateConstructors(ClassNode cNode) {
if (cNode.getDeclaredConstructors().size() != 0) {
// TODO: allow constructors which only call provided constructor?
addError("Explicit constructors not allowed for " + ImmutableASTTransformation.MY_TYPE_NAME + " class: " + cNode.getNameWithoutPackage(), cNode.getDeclaredConstructors().get(0));
}
return true;
}
private Statement createConstructorStatement(ClassNode cNode, PropertyNode pNode, List knownImmutableClasses, List knownImmutables) {
FieldNode fNode = pNode.getField();
final ClassNode fieldType = fNode.getType();
Statement statement = null;
if (fieldType.isArray() || isOrImplements(fieldType, CLONEABLE_TYPE)) {
statement = createConstructorStatementArrayOrCloneable(fNode);
} else if (isKnownImmutableClass(fieldType, knownImmutableClasses) || isKnownImmutable(pNode.getName(), knownImmutables)) {
statement = createConstructorStatementDefault(fNode);
} else if (fieldType.isDerivedFrom(DATE_TYPE)) {
statement = createConstructorStatementDate(fNode);
} else if (isOrImplements(fieldType, COLLECTION_TYPE) || fieldType.isDerivedFrom(COLLECTION_TYPE) || isOrImplements(fieldType, MAP_TYPE) || fieldType.isDerivedFrom(MAP_TYPE)) {
statement = createConstructorStatementCollection(fNode);
} else if (fieldType.isResolved()) {
addError(createErrorMessage(cNode.getName(), fNode.getName(), fieldType.getName(), "compiling"), fNode);
} else {
statement = createConstructorStatementGuarded(cNode, fNode);
}
return statement;
}
private Statement createConstructorStatementGuarded(ClassNode cNode, FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
Expression initExpr = fNode.getInitialValueExpression();
if (initExpr == null) initExpr = new ConstantExpression(null);
Expression unknown = findArg(fNode.getName());
return new IfStatement(
equalsNullExpr(unknown),
new IfStatement(
equalsNullExpr(initExpr),
new EmptyStatement(),
assignStatement(fieldExpr, checkUnresolved(cNode, fNode, initExpr))),
assignStatement(fieldExpr, checkUnresolved(cNode, fNode, unknown)));
}
private Expression checkUnresolved(ClassNode cNode, FieldNode fNode, Expression value) {
Expression args = new TupleExpression(new MethodCallExpression(new VariableExpression("this"), "getClass", ArgumentListExpression.EMPTY_ARGUMENTS), new ConstantExpression(fNode.getName()), value);
return new StaticMethodCallExpression(SELF_TYPE, "checkImmutable", args);
}
private Statement createConstructorStatementCollection(FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
Expression initExpr = fNode.getInitialValueExpression();
if (initExpr == null) initExpr = new ConstantExpression(null);
Expression collection = findArg(fNode.getName());
return new IfStatement(
equalsNullExpr(collection),
new IfStatement(
equalsNullExpr(initExpr),
new EmptyStatement(),
assignStatement(fieldExpr, cloneCollectionExpr(initExpr))),
new IfStatement(
isInstanceOf(collection, CLONEABLE_TYPE),
assignStatement(fieldExpr, cloneCollectionExpr(cloneArrayOrCloneableExpr(collection))),
assignStatement(fieldExpr, cloneCollectionExpr(collection))));
}
private boolean isKnownImmutableClass(ClassNode fieldType, List knownImmutableClasses) {
if (!fieldType.isResolved()) return false;
return fieldType.isEnum() ||
ClassHelper.isPrimitiveType(fieldType) ||
fieldType.getAnnotations(MY_TYPE).size() != 0 ||
inImmutableList(fieldType.getName()) ||
knownImmutableClasses.contains(fieldType.getName());
}
private boolean isKnownImmutable(String fieldName, List knownImmutables) {
return knownImmutables.contains(fieldName);
}
private static boolean inImmutableList(String typeName) {
return immutableList.contains(typeName);
}
private Statement createConstructorStatementArrayOrCloneable(FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
Expression initExpr = fNode.getInitialValueExpression();
if (initExpr == null) initExpr = new ConstantExpression(null);
final Expression array = findArg(fNode.getName());
return new IfStatement(
equalsNullExpr(array),
new IfStatement(
equalsNullExpr(initExpr),
assignStatement(fieldExpr, new ConstantExpression(null)),
assignStatement(fieldExpr, cloneArrayOrCloneableExpr(initExpr))),
assignStatement(fieldExpr, cloneArrayOrCloneableExpr(array)));
}
private Statement createConstructorStatementDate(FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
Expression initExpr = fNode.getInitialValueExpression();
if (initExpr == null) initExpr = new ConstantExpression(null);
final Expression date = findArg(fNode.getName());
return new IfStatement(
equalsNullExpr(date),
new IfStatement(
equalsNullExpr(initExpr),
assignStatement(fieldExpr, new ConstantExpression(null)),
assignStatement(fieldExpr, cloneDateExpr(initExpr))),
assignStatement(fieldExpr, cloneDateExpr(date)));
}
private Expression cloneDateExpr(Expression origDate) {
return new ConstructorCallExpression(DATE_TYPE,
new MethodCallExpression(origDate, "getTime", MethodCallExpression.NO_ARGUMENTS));
}
private void adjustPropertyForImmutability(PropertyNode pNode, List newNodes) {
final FieldNode fNode = pNode.getField();
fNode.setModifiers((pNode.getModifiers() & (~ACC_PUBLIC)) | ACC_FINAL | ACC_PRIVATE);
adjustPropertyNode(pNode, createGetterBody(fNode));
newNodes.add(pNode);
}
private void adjustPropertyNode(PropertyNode pNode, Statement getterBody) {
pNode.setSetterBlock(null);
pNode.setGetterBlock(getterBody);
}
private Statement createGetterBody(FieldNode fNode) {
BlockStatement body = new BlockStatement();
final ClassNode fieldType = fNode.getType();
final Statement statement;
if (fieldType.isArray() || isOrImplements(fieldType, CLONEABLE_TYPE)) {
statement = createGetterBodyArrayOrCloneable(fNode);
} else if (fieldType.isDerivedFrom(DATE_TYPE)) {
statement = createGetterBodyDate(fNode);
} else {
statement = createGetterBodyDefault(fNode);
}
body.addStatement(statement);
return body;
}
private static String createErrorMessage(String className, String fieldName, String typeName, String mode) {
return MY_TYPE_NAME + " processor doesn't know how to handle field '" + fieldName + "' of type '" +
prettyTypeName(typeName) + "' while " + mode + " class " + className + ".\n" +
MY_TYPE_NAME + " classes only support properties with effectively immutable types including:\n" +
"- Strings, primitive types, wrapper types, BigInteger and BigDecimal, enums\n" +
"- other " + MY_TYPE_NAME + " classes and known immutables (java.awt.Color, java.net.URI)\n" +
"- Cloneable classes, collections, maps and arrays, and other classes with special handling (java.util.Date)\n" +
"Other restrictions apply, please see the groovydoc for " + MY_TYPE_NAME + " for further details";
}
private static String prettyTypeName(String name) {
return name.equals("java.lang.Object") ? name + " or def" : name;
}
private Statement createGetterBodyArrayOrCloneable(FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
final Expression expression = cloneArrayOrCloneableExpr(fieldExpr);
return safeExpression(fieldExpr, expression);
}
private Statement createGetterBodyDate(FieldNode fNode) {
final Expression fieldExpr = new VariableExpression(fNode);
final Expression expression = cloneDateExpr(fieldExpr);
return safeExpression(fieldExpr, expression);
}
/**
* This method exists to be binary compatible with 1.7 - 1.8.6 compiled code.
*/
@SuppressWarnings("Unchecked")
public static Object checkImmutable(String className, String fieldName, Object field) {
if (field == null || field instanceof Enum || inImmutableList(field.getClass().getName())) return field;
if (field instanceof Collection) return DefaultGroovyMethods.asImmutable((Collection) field);
if (field.getClass().getAnnotation(MY_CLASS) != null) return field;
final String typeName = field.getClass().getName();
throw new RuntimeException(createErrorMessage(className, fieldName, typeName, "constructing"));
}
@SuppressWarnings("Unchecked")
public static Object checkImmutable(Class clazz, String fieldName, Object field) {
Immutable immutable = (Immutable) clazz.getAnnotation(MY_CLASS);
List knownImmutableClasses = new ArrayList();
if (immutable != null && immutable.knownImmutableClasses().length > 0) {
knownImmutableClasses = Arrays.asList(immutable.knownImmutableClasses());
}
if (field == null || field instanceof Enum || inImmutableList(field.getClass().getName()) || knownImmutableClasses.contains(field.getClass()))
return field;
if (field instanceof Collection) return DefaultGroovyMethods.asImmutable((Collection) field);
if (field.getClass().getAnnotation(MY_CLASS) != null) return field;
final String typeName = field.getClass().getName();
throw new RuntimeException(createErrorMessage(clazz.getName(), fieldName, typeName, "constructing"));
}
public static void checkPropNames(Object instance, Map args) {
final MetaClass metaClass = InvokerHelper.getMetaClass(instance);
for (String k : args.keySet()) {
if (metaClass.hasProperty(instance, k) == null)
throw new MissingPropertyException(k, instance.getClass());
}
}
}