| /* |
| * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file, and Oracle licenses the original version of this file under the BSD |
| * license: |
| */ |
| /* |
| Copyright 2009-2015 Attila Szegedi |
| |
| Licensed under both the Apache License, Version 2.0 (the "Apache License") |
| and the BSD License (the "BSD License"), with licensee being free to |
| choose either of the two at their discretion. |
| |
| You may not use this file except in compliance with either the Apache |
| License or the BSD License. |
| |
| If you choose to use this file in compliance with the Apache License, the |
| following notice applies to you: |
| |
| You may obtain a copy of the Apache 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. |
| |
| If you choose to use this file in compliance with the BSD License, the |
| following notice applies to you: |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are |
| met: |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| * Neither the name of the copyright holder nor the names of |
| contributors may be used to endorse or promote products derived from |
| this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
| IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A |
| PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER |
| BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
| BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package jdk.internal.dynalink.linker.support; |
| |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.lang.invoke.MethodType; |
| import jdk.internal.dynalink.DynamicLinkerFactory; |
| import jdk.internal.dynalink.linker.MethodHandleTransformer; |
| |
| /** |
| * Default implementation for a |
| * {@link DynamicLinkerFactory#setInternalObjectsFilter(MethodHandleTransformer)} |
| * that delegates to a pair of filtering method handles. It takes a method |
| * handle of {@code Object(Object)} type for filtering parameter values and |
| * another one of the same type for filtering return values. It applies them as |
| * parameter and return value filters on method handles passed to its |
| * {@link #transform(MethodHandle)} method, on those parameters and return values |
| * that are declared to have type {@link Object}. Also handles |
| * {@link MethodHandle#isVarargsCollector() method handles that support variable |
| * arity calls} with a last {@code Object[]} parameter. You can broadly think of |
| * the parameter filter as being a wrapping method for exposing internal runtime |
| * objects wrapped into an adapter with some public interface, and the return |
| * value filter as being its inverse unwrapping method. |
| */ |
| public class DefaultInternalObjectFilter implements MethodHandleTransformer { |
| private static final MethodHandle FILTER_VARARGS = new Lookup(MethodHandles.lookup()).findStatic( |
| DefaultInternalObjectFilter.class, "filterVarArgs", MethodType.methodType(Object[].class, MethodHandle.class, Object[].class)); |
| |
| private final MethodHandle parameterFilter; |
| private final MethodHandle returnFilter; |
| private final MethodHandle varArgFilter; |
| |
| /** |
| * Creates a new filter. |
| * @param parameterFilter the filter for method parameters. Must be of type |
| * {@code Object(Object)}, or {@code null}. |
| * @param returnFilter the filter for return values. Must be of type |
| * {@code Object(Object)}, or {@code null}. |
| * @throws IllegalArgumentException if one or both filters are not of the |
| * expected type. |
| */ |
| public DefaultInternalObjectFilter(final MethodHandle parameterFilter, final MethodHandle returnFilter) { |
| this.parameterFilter = checkHandle(parameterFilter, "parameterFilter"); |
| this.returnFilter = checkHandle(returnFilter, "returnFilter"); |
| this.varArgFilter = parameterFilter == null ? null : FILTER_VARARGS.bindTo(parameterFilter); |
| } |
| |
| @Override |
| public MethodHandle transform(final MethodHandle target) { |
| assert target != null; |
| MethodHandle[] filters = null; |
| final MethodType type = target.type(); |
| final boolean isVarArg = target.isVarargsCollector(); |
| final int paramCount = type.parameterCount(); |
| final MethodHandle paramsFiltered; |
| // Filter parameters |
| if (parameterFilter != null) { |
| int firstFilter = -1; |
| // Ignore receiver, start from argument 1 |
| for(int i = 1; i < paramCount; ++i) { |
| final Class<?> paramType = type.parameterType(i); |
| final boolean filterVarArg = isVarArg && i == paramCount - 1 && paramType == Object[].class; |
| if (filterVarArg || paramType == Object.class) { |
| if (filters == null) { |
| firstFilter = i; |
| filters = new MethodHandle[paramCount - firstFilter]; |
| } |
| filters[i - firstFilter] = filterVarArg ? varArgFilter : parameterFilter; |
| } |
| } |
| paramsFiltered = filters != null ? MethodHandles.filterArguments(target, firstFilter, filters) : target; |
| } else { |
| paramsFiltered = target; |
| } |
| // Filter return value if needed |
| final MethodHandle returnFiltered = returnFilter != null && type.returnType() == Object.class ? MethodHandles.filterReturnValue(paramsFiltered, returnFilter) : paramsFiltered; |
| // Preserve varargs collector state |
| return isVarArg && !returnFiltered.isVarargsCollector() ? returnFiltered.asVarargsCollector(type.parameterType(paramCount - 1)) : returnFiltered; |
| |
| } |
| |
| private static MethodHandle checkHandle(final MethodHandle handle, final String handleKind) { |
| if (handle != null) { |
| final MethodType objectObjectType = MethodType.methodType(Object.class, Object.class); |
| if (!handle.type().equals(objectObjectType)) { |
| throw new IllegalArgumentException("Method type for " + handleKind + " must be " + objectObjectType); |
| } |
| } |
| return handle; |
| } |
| |
| @SuppressWarnings("unused") |
| private static Object[] filterVarArgs(final MethodHandle parameterFilter, final Object[] args) throws Throwable { |
| Object[] newArgs = null; |
| for(int i = 0; i < args.length; ++i) { |
| final Object arg = args[i]; |
| final Object newArg = parameterFilter.invokeExact(arg); |
| if (arg != newArg) { |
| if (newArgs == null) { |
| newArgs = args.clone(); |
| } |
| newArgs[i] = newArg; |
| } |
| } |
| return newArgs == null ? args : newArgs; |
| } |
| } |