manifold.util.ReflectionHack_1212 Maven / Gradle / Ivy
/*
* Copyright (c) 2019 - Manifold Systems LLC
*
* 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 manifold.util;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Set;
import jdk.internal.reflect.Reflection;
import sun.misc.Unsafe;
/**
* Java 12 made changes in {@link Reflection} to filter fields that used to be available from calls such as
* {@code getDeclaredFields()}. Fields like 'override' are filtered, which messes up reflective calls that force needed
* access to otherwise inaccessible members.
*
* This class is a hack that shuts down the filtering added to Java 12.
*/
public class ReflectionHack_12
{
public static void hackReflection()
{
try
{
Unsafe unsafe = NecessaryEvilUtil.getUnsafe();
// Must approximate the {@link AccessibleObject#override} field offset (because it is one of the filtered fields)
long overrideOffset = AccessibleObject_layout.getOverrideOffset( unsafe );
// Change the value in Reflection.ALL_MEMBERS singleton set so that nothing is filtered
Method addOpens = Module.class.getDeclaredMethod( "implAddOpens", String.class, Module.class );
unsafe.putObject( addOpens, overrideOffset, true );
addOpens.invoke( String.class.getModule(), "jdk.internal.reflect", NecessaryEvilUtil.class.getModule() );
//SharedSecrets.getJavaLangAccess().addExports( String.class.getModule(), "jdk.internal.reflect", NecessaryEvilUtil.class.getModule() );
Set allFilter = Reflection.ALL_MEMBERS;
Field e0 = allFilter.getClass().getDeclaredField( "e0" );
long i_e0 = unsafe.objectFieldOffset( e0 );
unsafe.putObject( allFilter, i_e0, "" );
}
catch( Exception e )
{
throw new RuntimeException( e );
}
}
}