/*
* Copyright 2008 Google Inc.
*
* 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 com.google.gwt.dev.javac;
import com.google.gwt.dev.jdt.SafeASTVisitor;
import com.google.gwt.dev.util.InstalledHelpInfo;
import com.google.gwt.dev.util.collect.Stack;
import com.google.gwt.thirdparty.guava.common.base.Strings;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ast.ASTNode;
import org.eclipse.jdt.internal.compiler.ast.AllocationExpression;
import org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration;
import org.eclipse.jdt.internal.compiler.ast.ConstructorDeclaration;
import org.eclipse.jdt.internal.compiler.ast.FieldDeclaration;
import org.eclipse.jdt.internal.compiler.ast.MethodDeclaration;
import org.eclipse.jdt.internal.compiler.ast.TypeDeclaration;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.lookup.AnnotationBinding;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.ClassScope;
import org.eclipse.jdt.internal.compiler.lookup.CompilationUnitScope;
import org.eclipse.jdt.internal.compiler.lookup.MethodBinding;
import org.eclipse.jdt.internal.compiler.lookup.MethodScope;
import org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding;
import org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import java.util.HashMap;
import java.util.Map;
/**
* Check a compilation unit for violations of
* {@link com.google.gwt.core.client.JavaScriptObject JavaScriptObject} (JSO)
* restrictions. The restrictions are summarized in
* <code>jsoRestrictions.html</code>.
*
*
* Any violations found are attached as errors on the
* CompilationUnitDeclaration.
*
* @see <a
* href="http://code.google.com/p/google-web-toolkit/wiki/OverlayTypes">Overlay
* types design doc</a>
* @see jsoRestrictions.html
*/
public class JSORestrictionsChecker {
public static final String ERR_JSTYPE_OVERLOADS_NOT_ALLOWED =
"JsType methods cannot overload another method.";
public static final String ERR_JSEXPORT_ONLY_CTORS_AND_STATIC_METHODS =
"@JsExport may only be applied to constructors and static methods.";
public static final String ERR_JSPROPERTY_ONLY_BEAN_OR_FLUENT_STYLE_NAMING =
"@JsProperty is only allowed on JavaBean-style or fluent-style named methods";
public static final String ERR_MUST_EXTEND_MAGIC_PROTOTYPE_CLASS =
"Classes implementing @JsType with a prototype must extend that interface's Prototype class";
public static final String ERR_CLASS_EXTENDS_MAGIC_PROTOTYPE_BUT_NO_PROTOTYPE_ATTRIBUTE =
"Classes implementing a @JsType without a prototype should not extend the Prototype class";
public static final String ERR_JSPROPERTY_ONLY_ON_INTERFACES =
"@JsProperty not allowed on concrete class methods";
public static final String ERR_CONSTRUCTOR_WITH_PARAMETERS =
"Constructors must not have parameters in subclasses of JavaScriptObject";
public static final String ERR_INSTANCE_FIELD = "Instance fields cannot be used in subclasses of JavaScriptObject";
public static final String ERR_INSTANCE_METHOD_NONFINAL =
"Instance methods must be 'final' in non-final subclasses of JavaScriptObject";
public static final String ERR_IS_NONSTATIC_NESTED = "Nested classes must be 'static' if they extend JavaScriptObject";
public static final String ERR_NEW_JSO =
"'new' cannot be used to create instances of JavaScriptObject subclasses; instances must originate in JavaScript";
public static final String ERR_NONEMPTY_CONSTRUCTOR =
"Constructors must be totally empty in subclasses of JavaScriptObject";
public static final String ERR_NONPROTECTED_CONSTRUCTOR =
"Constructors must be 'protected' in subclasses of JavaScriptObject";
public static final String ERR_OVERRIDDEN_METHOD =
"Methods cannot be overridden in JavaScriptObject subclasses";
public static final String JSO_CLASS = "com/google/gwt/core/client/JavaScriptObject";
public static final String ERR_FORGOT_TO_MAKE_PROTOTYPE_IMPL_JSTYPE = "@JsType subtype extends magic _Prototype class, but _Prototype class doesn't implement JsType";
public static final String ERR_SUBCLASSING_NATIVE_NOT_ALLOWED = "Subclassing prototypes of native browser prototypes not allowed.";
public static final String ERR_JS_TYPE_WITH_PROTOTYPE_SET_NOT_ALLOWED_ON_CLASS_TYPES = "@JsType with prototype set not allowed on class types";
static boolean LINT_MODE = false;
private enum ClassState {
NORMAL, JSO, JSTYPE, JSTYPE_IMPL
}
/**
* The order in which the checker will process types is undefined, so this
* type accumulates the information necessary for sanity-checking the JSO
* types.
*/
public static class CheckerState {
private final Map<String, String> interfacesToJsoImpls = new HashMap<String, String>();
public void addJsoInterface(TypeDeclaration jsoType,
CompilationUnitDeclaration cud, ReferenceBinding interf) {
String intfName = CharOperation.toString(interf.compoundName);
String alreadyImplementor = interfacesToJsoImpls.get(intfName);
String myName = CharOperation.toString(jsoType.binding.compoundName);
if (!areInSameModule(jsoType, interf)) {
String msg = errMustBeDefinedInTheSameModule(intfName,myName);
errorOn(jsoType, cud, msg);
return;
}
if (alreadyImplementor != null) {
String msg = errAlreadyImplemented(intfName, alreadyImplementor, myName);
errorOn(jsoType, cud, msg);
return;
}
interfacesToJsoImpls.put(intfName, myName);
}
// TODO(rluble): (Separate compilation) Implement a real check that a JSO must is defined in
// the same module as the interface(s) it implements. Depends on upcoming JProgram changes.
private boolean areInSameModule(TypeDeclaration jsoType, ReferenceBinding interf) {
return true;
}
public String getJsoImplementor(ReferenceBinding binding) {
String name = CharOperation.toString(binding.compoundName);
return interfacesToJsoImpls.get(name);
}
public boolean isJsoInterface(ReferenceBinding binding) {
String name = CharOperation.toString(binding.compoundName);
return interfacesToJsoImpls.containsKey(name);
}
}
private class JSORestrictionsVisitor extends SafeASTVisitor implements
ClassFileConstants {
private final Stack<ClassState> classStateStack = new Stack<ClassState>();
@Override
public void endVisit(AllocationExpression exp, BlockScope scope) {
// In rare cases we might not be able to resolve the expression.
if (exp.type == null) {
return;
}
TypeBinding resolvedType = exp.resolvedType;
if (resolvedType == null) {
if (scope == null) {
return;
}
resolvedType = exp.type.resolveType(scope);
}
// Anywhere an allocation occurs is wrong.
if (isJsoSubclass(resolvedType)) {
errorOn(exp, ERR_NEW_JSO);
}
}
@Override
public void endVisit(ConstructorDeclaration meth, ClassScope scope) {
if (!isJso()) {
return;
}
if ((meth.arguments != null) && (meth.arguments.length > 0)) {
errorOn(meth, ERR_CONSTRUCTOR_WITH_PARAMETERS);
}
if ((meth.modifiers & AccProtected) == 0) {
errorOn(meth, ERR_NONPROTECTED_CONSTRUCTOR);
}
if (meth.statements != null && meth.statements.length > 0) {
errorOn(meth, ERR_NONEMPTY_CONSTRUCTOR);
}
}
@Override
public void endVisit(FieldDeclaration field, MethodScope scope) {
if (!isJso()) {
return;
}
if (!field.isStatic()) {
errorOn(field, ERR_INSTANCE_FIELD);
}
}
@Override
public void endVisit(MethodDeclaration meth, ClassScope scope) {
if (!isJso()) {
return;
}
if ((meth.modifiers & (AccFinal | AccPrivate | AccStatic)) == 0) {
// The method's modifiers allow it to be overridden. Make
// one final check to see if the surrounding class is final.
if ((meth.scope == null) || !meth.scope.enclosingSourceType().isFinal()) {
errorOn(meth, ERR_INSTANCE_METHOD_NONFINAL);
}
}
// Should not have to check isStatic() here, but isOverriding() appears
// to be set for static methods.
if (!meth.isStatic()
&& (meth.binding != null && meth.binding.isOverriding())) {
errorOn(meth, ERR_OVERRIDDEN_METHOD);
}
}
@Override
public void endVisit(TypeDeclaration type, ClassScope scope) {
popState();
}
@Override
public void endVisit(TypeDeclaration type, CompilationUnitScope scope) {
popState();
}
@Override
public void endVisitValid(TypeDeclaration type, BlockScope scope) {
popState();
}
@Override
public boolean visit(TypeDeclaration type, ClassScope scope) {
pushState(checkType(type));
return true;
}
@Override
public boolean visit(TypeDeclaration type, CompilationUnitScope scope) {
pushState(checkType(type));
return true;
}
@Override
public boolean visitValid(TypeDeclaration type, BlockScope scope) {
pushState(checkType(type));
return true;
}
private void checkJsType(TypeDeclaration type, TypeBinding typeBinding) {
ReferenceBinding binding = (ReferenceBinding) typeBinding;
if (binding.isClass()) {
AnnotationBinding jsinterfaceAnn = JdtUtil.getAnnotation(typeBinding,
JsInteropUtil.JSTYPE_CLASS);
String jsPrototype = JdtUtil.getAnnotationParameterString(jsinterfaceAnn, "prototype");
if (jsPrototype != null && !"".equals(jsPrototype)) {
errorOn(type, ERR_JS_TYPE_WITH_PROTOTYPE_SET_NOT_ALLOWED_ON_CLASS_TYPES);
}
}
Map<String, MethodBinding> methodSignatures = new HashMap<String, MethodBinding>();
Map<String, MethodBinding> noExports = new HashMap<String, MethodBinding>();
checkJsTypeMethodsForOverloads(methodSignatures, noExports, binding);
for (MethodBinding mb : binding.methods()) {
checkJsProperty(mb, true);
checkJsExport(mb, !binding.isInterface());
}
}
private void checkJsExport(MethodBinding mb, boolean allowed) {
AnnotationBinding jsExport = JdtUtil.getAnnotation(mb, JsInteropUtil.JSEXPORT_CLASS);
if (jsExport != null && allowed) {
if (!mb.isConstructor() && !mb.isStatic()) {
errorOn(mb, ERR_JSEXPORT_ONLY_CTORS_AND_STATIC_METHODS);
}
}
}
private void checkJsProperty(MethodBinding mb, boolean allowed) {
AnnotationBinding jsProperty = JdtUtil.getAnnotation(mb, JsInteropUtil.JSPROPERTY_CLASS);
if (jsProperty != null) {
if (!allowed) {
errorOn(mb, ERR_JSPROPERTY_ONLY_ON_INTERFACES);
return;
}
String methodName = String.valueOf(mb.selector);
if (!isGetter(methodName, mb) && !isSetter(methodName, mb) && !isHas(methodName, mb)) {
errorOn(mb, ERR_JSPROPERTY_ONLY_BEAN_OR_FLUENT_STYLE_NAMING);
}
}
}
private boolean isGetter(String name, MethodBinding mb) {
// zero arg non-void getX()
if (name.length() > 3 && name.startsWith("get") && Character.isUpperCase(name.charAt(3)) &&
mb.returnType == TypeBinding.VOID && mb.parameters.length == 0) {
return true;
} else if (name.length() > 3 && name.startsWith("is")
&& Character.isUpperCase(name.charAt(2)) && mb.returnType == TypeBinding.BOOLEAN
&& mb.parameters.length == 0) {
return true;
} else if (mb.parameters.length == 0 && mb.returnType != TypeBinding.VOID) {
return true;
}
return false;
}
private boolean isSetter(String name, MethodBinding mb) {
if (mb.returnType == TypeBinding.VOID || mb.returnType == mb.declaringClass) {
if (name.length() > 3 && name.startsWith("set") && Character.isUpperCase(name.charAt(3))
&& mb.parameters.length == 1) {
return true;
} else if (mb.parameters.length == 1) {
return true;
}
}
return false;
}
private boolean isHas(String name, MethodBinding mb) {
if (name.length() > 3 && name.startsWith("has") && Character.isUpperCase(name.charAt(3))
&& mb.parameters.length == 0 && mb.returnType == TypeBinding.BOOLEAN) {
return true;
}
return false;
}
private void checkJsTypeMethodsForOverloads(Map<String, MethodBinding> methodNamesAndSigs,
Map<String, MethodBinding> noExports,
ReferenceBinding binding) {
if (isJsType(binding)) {
for (MethodBinding mb : binding.methods()) {
String methodName = String.valueOf(mb.selector);
if (JdtUtil.getAnnotation(mb, JsInteropUtil.JSNOEXPORT_CLASS) != null) {
noExports.put(methodName, mb);
continue;
}
if (mb.isConstructor() || mb.isStatic()) {
continue;
}
if (JdtUtil.getAnnotation(mb, JsInteropUtil.JSPROPERTY_CLASS) != null) {
if (isGetter(methodName, mb) || isSetter(methodName, mb) || isHas(methodName, mb)) {
// js properties are allowed to be overloaded (setter/getter)
continue;
}
}
if (methodNamesAndSigs.containsKey(methodName)) {
if (!methodNamesAndSigs.get(methodName).areParameterErasuresEqual(mb)) {
if (noExports.containsKey(methodName)
&& noExports.get(methodName).areParameterErasuresEqual(mb)) {
continue;
}
errorOn(mb, ERR_JSTYPE_OVERLOADS_NOT_ALLOWED);
}
} else {
methodNamesAndSigs.put(methodName, mb);
}
}
}
for (ReferenceBinding rb : binding.superInterfaces()) {
checkJsTypeMethodsForOverloads(methodNamesAndSigs, noExports, rb);
}
}
private ClassState checkType(TypeDeclaration type) {
SourceTypeBinding binding = type.binding;
if (isJsType(type.binding)) {
checkJsType(type, type.binding);
return ClassState.JSTYPE;
}
if (checkClassImplementingJsType(type)) {
return ClassState.JSTYPE_IMPL;
}
if (!isJsoSubclass(binding)) {
return ClassState.NORMAL;
}
if (type.enclosingType != null && !binding.isStatic()) {
errorOn(type, ERR_IS_NONSTATIC_NESTED);
}
ReferenceBinding[] interfaces = binding.superInterfaces();
if (interfaces != null) {
for (ReferenceBinding interf : interfaces) {
if (interf.methods() == null) {
continue;
}
if (interf.methods().length > 0) {
// See if any of my superTypes implement it.
ReferenceBinding superclass = binding.superclass();
if (superclass == null
|| !superclass.implementsInterface(interf, true)) {
state.addJsoInterface(type, cud, interf);
}
}
}
}
return ClassState.JSO;
}
private boolean checkClassImplementingJsType(TypeDeclaration type) {
ReferenceBinding jsInterface = findNearestJsTypeRecursive(type.binding);
if (jsInterface == null) {
return false;
}
for (MethodBinding mb : type.binding.methods()) {
checkJsExport(mb, true);
checkJsProperty(mb, false);
}
AnnotationBinding jsinterfaceAnn = JdtUtil.getAnnotation(jsInterface,
JsInteropUtil.JSTYPE_CLASS);
String jsPrototype = JdtUtil.getAnnotationParameterString(jsinterfaceAnn, "prototype");
boolean isNative = JdtUtil.getAnnotationParameterBoolean(jsinterfaceAnn, "isNative");
if (!Strings.isNullOrEmpty(jsPrototype)) {
checkClassExtendsMagicPrototype(type, jsInterface, !isNative, isNative);
} else {
checkClassExtendsMagicPrototype(type, jsInterface, false, isNative);
}
// TODO(cromwellian) add multiple-inheritance checks when ambiguity in spec is resolved
return true;
}
private void checkClassExtendsMagicPrototype(TypeDeclaration type, ReferenceBinding jsInterface,
boolean shouldExtend, boolean isNative) {
ReferenceBinding superClass = type.binding.superclass();
// if type is the _Prototype stub (implements JsType) exit
if (isMagicPrototype(type.binding, jsInterface)) {
return;
} else if (isMagicPrototypeStub(type)) {
errorOn(type, ERR_FORGOT_TO_MAKE_PROTOTYPE_IMPL_JSTYPE);
}
if (shouldExtend) {
// super class should be SomeInterface.Prototype, so enclosing type should match the jsInterface
if (LINT_MODE && (superClass == null || !isMagicPrototype(superClass, jsInterface))) {
errorOn(type, ERR_MUST_EXTEND_MAGIC_PROTOTYPE_CLASS);
}
} else {
if (superClass != null && isMagicPrototype(superClass, jsInterface)) {
if (!isNative) {
errorOn(type, ERR_CLASS_EXTENDS_MAGIC_PROTOTYPE_BUT_NO_PROTOTYPE_ATTRIBUTE);
} else {
errorOn(type, ERR_SUBCLASSING_NATIVE_NOT_ALLOWED);
}
}
}
}
// Roughly parallels JProgram.isJsTypePrototype()
private boolean isMagicPrototype(ReferenceBinding type, ReferenceBinding jsInterface) {
if (isMagicPrototypeStub(type)) {
for (ReferenceBinding intf : type.superInterfaces()) {
if (intf == jsInterface) {
return true;
}
}
}
return false;
}
private boolean isMagicPrototypeStub(TypeDeclaration type) {
return isMagicPrototypeStub(type.binding);
}
private boolean isMagicPrototypeStub(ReferenceBinding binding) {
return JdtUtil.getAnnotation(binding, JsInteropUtil.JSTYPEPROTOTYPE_CLASS) != null;
}
/**
* Walks up chain of interfaces and superinterfaces to find the first one marked with @JsType.
*/
private ReferenceBinding findNearestJsType(ReferenceBinding binding, boolean mustHavePrototype) {
if (isJsType(binding)) {
return binding;
}
for (ReferenceBinding intb : binding.superInterfaces()) {
ReferenceBinding checkSuperInt = findNearestJsType(intb, false);
if (checkSuperInt != null) {
return checkSuperInt;
}
}
return null;
}
private ReferenceBinding findNearestJsTypeRecursive(ReferenceBinding binding) {
ReferenceBinding nearest = findNearestJsType(binding, false);
if (nearest != null) {
return nearest;
} else if (binding.superclass() != null) {
return findNearestJsTypeRecursive(binding.superclass());
}
return null;
}
private boolean isJso() {
return classStateStack.peek() == ClassState.JSO;
}
private void popState() {
classStateStack.pop();
}
private void pushState(ClassState cstate) {
classStateStack.push(cstate);
}
}
/**
* Checks an entire
* {@link org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration}.
*
*/
public static void check(CheckerState state, CompilationUnitDeclaration cud) {
JSORestrictionsChecker checker = new JSORestrictionsChecker(state, cud);
checker.check();
}
/**
* Returns {@code true} if {@code typeBinding} is {@code JavaScriptObject} or
* any subtype.
*/
public static boolean isJso(TypeBinding typeBinding) {
if (!(typeBinding instanceof ReferenceBinding)) {
return false;
}
ReferenceBinding binding = (ReferenceBinding) typeBinding;
while (binding != null) {
if (JSO_CLASS.equals(String.valueOf(binding.constantPoolName()))) {
return true;
}
binding = binding.superclass();
}
return false;
}
/**
* Returns the first JsType annotation encountered traversing the type hierarchy upwards from the type.
*/
private boolean isJsType(TypeBinding typeBinding) {
if (!(typeBinding instanceof ReferenceBinding) || !(typeBinding instanceof SourceTypeBinding)) {
return false;
}
AnnotationBinding jsInterface = JdtUtil.getAnnotation(typeBinding, JsInteropUtil.JSTYPE_CLASS);
return jsInterface != null;
}
/**
* Returns {@code true} if {@code typeBinding} is a subtype of
* {@code JavaScriptObject}, but not {@code JavaScriptObject} itself.
*/
public static boolean isJsoSubclass(TypeBinding typeBinding) {
if (!(typeBinding instanceof ReferenceBinding)) {
return false;
}
ReferenceBinding binding = (ReferenceBinding) typeBinding;
return isJso(binding.superclass());
}
static String errAlreadyImplemented(String intfName, String impl1,
String impl2) {
return "Only one JavaScriptObject type may implement the methods of an "
+ "interface that declared methods. The interface (" + intfName
+ ") is implemented by both (" + impl1 + ") and (" + impl2 + ")";
}
// TODO(rluble): (Separate compilation) It would be nice to have the actual module names here.
static String errMustBeDefinedInTheSameModule(String intfName, String jsoImplementation) {
return "A JavaScriptObject type may only implement an interface that is defined in the same"
+ " module. The interface (" + intfName + ") and the JavaScriptObject type (" +
jsoImplementation + ") are defined different modules";
}
private static void errorOn(ASTNode node, CompilationUnitDeclaration cud,
String error) {
GWTProblem.recordError(node, cud, error, new InstalledHelpInfo(
"jsoRestrictions.html"));
}
private final CompilationUnitDeclaration cud;
private final CheckerState state;
private JSORestrictionsChecker(CheckerState state,
CompilationUnitDeclaration cud) {
this.cud = cud;
this.state = state;
}
private void check() {
cud.traverse(new JSORestrictionsVisitor(), cud.scope);
}
private void errorOn(ASTNode node, String error) {
errorOn(node, cud, error);
}
private void errorOn(MethodBinding mb, String error) {
ASTNode node = JdtUtil.safeSourceMethod(mb);
if (node == null) {
node = cud;
// Workaround for bad JDT bug
error = "Error in " + mb.toString() + ": " + error;
}
errorOn(node, cud, error);
}
}