com.google.gwt.dev.jjs.impl.ReplaceGetClassOverrides Maven / Gradle / Ivy
/*
* Copyright 2011 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.jjs.impl;
import com.google.gwt.dev.jjs.ast.Context;
import com.google.gwt.dev.jjs.ast.JField;
import com.google.gwt.dev.jjs.ast.JFieldRef;
import com.google.gwt.dev.jjs.ast.JMethod;
import com.google.gwt.dev.jjs.ast.JMethodCall;
import com.google.gwt.dev.jjs.ast.JModVisitor;
import com.google.gwt.dev.jjs.ast.JProgram;
import com.google.gwt.dev.jjs.ast.JType;
import com.google.gwt.dev.jjs.ast.RuntimeConstants;
/**
* Prune all overrides of Object.getClass() and inline all method calls to Object.getClass()
* as Object.___clazz.
*
* The Devirtualizer pass needs to run before this pass.
*/
public class ReplaceGetClassOverrides {
public static void exec(JProgram program) {
new GetClassInlinerRemover(program).accept(program);
}
private static class GetClassInlinerRemover extends JModVisitor {
private JProgram program;
private JMethod getClassMethod;
private JField clazzField;
public GetClassInlinerRemover(JProgram program) {
this.program = program;
getClassMethod = program.getIndexedMethod(RuntimeConstants.OBJECT_GET_CLASS);
clazzField = program.getIndexedField(RuntimeConstants.OBJECT_CLAZZ);
}
@Override
public void endVisit(JMethod x, Context ctx) {
if (!isGetClassMethod(x)) {
return;
}
if (x.getEnclosingType() == program.getTypeJavaLangObject()) {
// Remove all overrides but keep the method in java.lang.Object as references from JSNI
// are not removed.
x.getOverridingMethods().clear();
return;
}
ctx.removeMe();
}
@Override
public void endVisit(JMethodCall x, Context ctx) {
// All calls to getClass with reference to Object.clazz field
if (isGetClassMethod(x.getTarget())) {
assert !isGetClassDevirtualized(x.getTarget().getEnclosingType());
ctx.replaceMe(new JFieldRef(x.getSourceInfo(), x.getInstance(),
clazzField, clazzField.getEnclosingType()));
}
}
private boolean isGetClassMethod(JMethod method) {
return method == getClassMethod || method.getOverriddenMethods().contains(getClassMethod);
}
private boolean isGetClassDevirtualized(JType type) {
return type == program.getJavaScriptObject()
|| program.getRepresentedAsNativeTypes().contains(type)
|| type.isJsNative();
}
}
}