| /* |
| * Copyright (c) 2010, 2013, 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. |
| */ |
| |
| package jdk.nashorn.internal.runtime.linker; |
| |
| import static jdk.nashorn.internal.lookup.Lookup.MH; |
| |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.lang.invoke.MethodType; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| import java.util.function.Supplier; |
| import jdk.dynalink.CallSiteDescriptor; |
| import jdk.dynalink.NamedOperation; |
| import jdk.dynalink.Operation; |
| import jdk.dynalink.SecureLookupSupplier; |
| import jdk.dynalink.StandardNamespace; |
| import jdk.dynalink.StandardOperation; |
| import jdk.dynalink.beans.BeansLinker; |
| import jdk.dynalink.linker.ConversionComparator.Comparison; |
| import jdk.dynalink.linker.GuardedInvocation; |
| import jdk.dynalink.linker.GuardingDynamicLinker; |
| import jdk.dynalink.linker.LinkRequest; |
| import jdk.dynalink.linker.LinkerServices; |
| import jdk.dynalink.linker.MethodHandleTransformer; |
| import jdk.dynalink.linker.support.DefaultInternalObjectFilter; |
| import jdk.dynalink.linker.support.Lookup; |
| import jdk.dynalink.linker.support.SimpleLinkRequest; |
| import jdk.nashorn.api.scripting.ScriptUtils; |
| import jdk.nashorn.internal.runtime.ConsString; |
| import jdk.nashorn.internal.runtime.Context; |
| import jdk.nashorn.internal.runtime.ScriptObject; |
| import jdk.nashorn.internal.runtime.options.Options; |
| |
| /** |
| * This linker delegates to a {@code BeansLinker} but passes it a special linker services object that has a modified |
| * {@code compareConversion} method that favors conversion of {@link ConsString} to either {@link String} or |
| * {@link CharSequence}. It also provides a {@link #createHiddenObjectFilter()} method for use with bootstrap that will |
| * ensure that we never pass internal engine objects that should not be externally observable (currently ConsString and |
| * ScriptObject) to Java APIs, but rather that we flatten it into a String. We can't just add this functionality as |
| * custom converters via {@code GuaardingTypeConverterFactory}, since they are not consulted when |
| * the target method handle parameter signature is {@code Object}. This linker also makes sure that primitive |
| * {@link String} operations can be invoked on a {@link ConsString}, and allows invocation of objects implementing |
| * the {@link FunctionalInterface} attribute. |
| */ |
| public class NashornBeansLinker implements GuardingDynamicLinker { |
| // System property to control whether to wrap ScriptObject->ScriptObjectMirror for |
| // Object type arguments of Java method calls, field set and array set. |
| private static final boolean MIRROR_ALWAYS = Options.getBooleanProperty("nashorn.mirror.always", true); |
| |
| private static final Operation GET_METHOD = StandardOperation.GET.withNamespace(StandardNamespace.METHOD); |
| private static final MethodType GET_METHOD_TYPE = MethodType.methodType(Object.class, Object.class); |
| |
| private static final MethodHandle EXPORT_ARGUMENT; |
| private static final MethodHandle IMPORT_RESULT; |
| private static final MethodHandle FILTER_CONSSTRING; |
| |
| static { |
| final Lookup lookup = new Lookup(MethodHandles.lookup()); |
| EXPORT_ARGUMENT = lookup.findOwnStatic("exportArgument", Object.class, Object.class); |
| IMPORT_RESULT = lookup.findOwnStatic("importResult", Object.class, Object.class); |
| FILTER_CONSSTRING = lookup.findOwnStatic("consStringFilter", Object.class, Object.class); |
| } |
| |
| // cache of @FunctionalInterface method of implementor classes |
| private static final ClassValue<String> FUNCTIONAL_IFACE_METHOD_NAME = new ClassValue<String>() { |
| @Override |
| protected String computeValue(final Class<?> type) { |
| return findFunctionalInterfaceMethodName(type); |
| } |
| }; |
| |
| private final BeansLinker beansLinker; |
| |
| NashornBeansLinker(final BeansLinker beansLinker) { |
| this.beansLinker = beansLinker; |
| } |
| |
| @Override |
| public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { |
| final Object self = linkRequest.getReceiver(); |
| final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor(); |
| if (self instanceof ConsString) { |
| // In order to treat ConsString like a java.lang.String we need a link request with a string receiver. |
| final Object[] arguments = linkRequest.getArguments(); |
| arguments[0] = ""; |
| final LinkRequest forgedLinkRequest = linkRequest.replaceArguments(desc, arguments); |
| final GuardedInvocation invocation = getGuardedInvocation(beansLinker, forgedLinkRequest, linkerServices); |
| // If an invocation is found we add a filter that makes it work for both Strings and ConsStrings. |
| return invocation == null ? null : invocation.filterArguments(0, FILTER_CONSSTRING); |
| } |
| |
| if (self != null && NamedOperation.getBaseOperation(desc.getOperation()) == StandardOperation.CALL) { |
| // Support CALL on any object that supports some @FunctionalInterface |
| // annotated interface. This way Java method, constructor references or |
| // implementations of java.util.function.* interfaces can be called as though |
| // those are script functions. |
| final String name = getFunctionalInterfaceMethodName(self.getClass()); |
| if (name != null) { |
| // Obtain the method |
| final CallSiteDescriptor getMethodDesc = new CallSiteDescriptor( |
| NashornCallSiteDescriptor.getLookupInternal(desc), |
| GET_METHOD.named(name), GET_METHOD_TYPE); |
| final GuardedInvocation getMethodInv = linkerServices.getGuardedInvocation( |
| new SimpleLinkRequest(getMethodDesc, false, self)); |
| final Object method; |
| try { |
| method = getMethodInv.getInvocation().invokeExact(self); |
| } catch (final Exception|Error e) { |
| throw e; |
| } catch (final Throwable t) { |
| throw new RuntimeException(t); |
| } |
| |
| final Object[] args = linkRequest.getArguments(); |
| args[1] = args[0]; // callee (the functional object) becomes this |
| args[0] = method; // the method becomes the callee |
| |
| final MethodType callType = desc.getMethodType(); |
| |
| final CallSiteDescriptor newDesc = desc.changeMethodType( |
| desc.getMethodType().changeParameterType(0, Object.class).changeParameterType(1, callType.parameterType(0))); |
| final GuardedInvocation gi = getGuardedInvocation(beansLinker, linkRequest.replaceArguments(newDesc, args), |
| new NashornBeansLinkerServices(linkerServices)); |
| |
| // Bind to the method, drop the original "this" and use original "callee" as this: |
| final MethodHandle inv = gi.getInvocation() // (method, this, args...) |
| .bindTo(method); // (this, args...) |
| final MethodHandle calleeToThis = MH.dropArguments(inv, 1, callType.parameterType(1)); // (callee->this, <drop>, args...) |
| return gi.replaceMethods(calleeToThis, gi.getGuard()); |
| } |
| } |
| return getGuardedInvocation(beansLinker, linkRequest, linkerServices); |
| } |
| |
| /** |
| * Delegates to the specified linker but injects its linker services wrapper so that it will apply all special |
| * conversions that this class does. |
| * @param delegateLinker the linker to which the actual work is delegated to. |
| * @param linkRequest the delegated link request |
| * @param linkerServices the original link services that will be augmented with special conversions |
| * @return the guarded invocation from the delegate, possibly augmented with special conversions |
| * @throws Exception if the delegate throws an exception |
| */ |
| public static GuardedInvocation getGuardedInvocation(final GuardingDynamicLinker delegateLinker, final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { |
| return delegateLinker.getGuardedInvocation(linkRequest, new NashornBeansLinkerServices(linkerServices)); |
| } |
| |
| @SuppressWarnings("unused") |
| private static Object exportArgument(final Object arg) { |
| return exportArgument(arg, MIRROR_ALWAYS); |
| } |
| |
| static Object exportArgument(final Object arg, final boolean mirrorAlways) { |
| if (arg instanceof ConsString) { |
| return arg.toString(); |
| } else if (mirrorAlways && arg instanceof ScriptObject) { |
| return ScriptUtils.wrap(arg); |
| } else { |
| return arg; |
| } |
| } |
| |
| @SuppressWarnings("unused") |
| private static Object importResult(final Object arg) { |
| return ScriptUtils.unwrap(arg); |
| } |
| |
| @SuppressWarnings("unused") |
| private static Object consStringFilter(final Object arg) { |
| return arg instanceof ConsString ? arg.toString() : arg; |
| } |
| |
| private static String findFunctionalInterfaceMethodName(final Class<?> clazz) { |
| if (clazz == null) { |
| return null; |
| } |
| |
| for (final Class<?> iface : clazz.getInterfaces()) { |
| // check accessibility up-front |
| if (! Context.isAccessibleClass(iface)) { |
| continue; |
| } |
| |
| // check for @FunctionalInterface |
| if (iface.isAnnotationPresent(FunctionalInterface.class)) { |
| // return the first abstract method |
| for (final Method m : iface.getMethods()) { |
| if (Modifier.isAbstract(m.getModifiers()) && !isOverridableObjectMethod(m)) { |
| return m.getName(); |
| } |
| } |
| } |
| } |
| |
| // did not find here, try super class |
| return findFunctionalInterfaceMethodName(clazz.getSuperclass()); |
| } |
| |
| // is this an overridable java.lang.Object method? |
| private static boolean isOverridableObjectMethod(final Method m) { |
| switch (m.getName()) { |
| case "equals": |
| if (m.getReturnType() == boolean.class) { |
| final Class<?>[] params = m.getParameterTypes(); |
| return params.length == 1 && params[0] == Object.class; |
| } |
| return false; |
| case "hashCode": |
| return m.getReturnType() == int.class && m.getParameterCount() == 0; |
| case "toString": |
| return m.getReturnType() == String.class && m.getParameterCount() == 0; |
| } |
| return false; |
| } |
| |
| // Returns @FunctionalInterface annotated interface's single abstract |
| // method name. If not found, returns null. |
| static String getFunctionalInterfaceMethodName(final Class<?> clazz) { |
| return FUNCTIONAL_IFACE_METHOD_NAME.get(clazz); |
| } |
| |
| static MethodHandleTransformer createHiddenObjectFilter() { |
| return new DefaultInternalObjectFilter(EXPORT_ARGUMENT, MIRROR_ALWAYS ? IMPORT_RESULT : null); |
| } |
| |
| private static class NashornBeansLinkerServices implements LinkerServices { |
| private final LinkerServices linkerServices; |
| |
| NashornBeansLinkerServices(final LinkerServices linkerServices) { |
| this.linkerServices = linkerServices; |
| } |
| |
| @Override |
| public MethodHandle asType(final MethodHandle handle, final MethodType fromType) { |
| return linkerServices.asType(handle, fromType); |
| } |
| |
| @Override |
| public MethodHandle getTypeConverter(final Class<?> sourceType, final Class<?> targetType) { |
| return linkerServices.getTypeConverter(sourceType, targetType); |
| } |
| |
| @Override |
| public boolean canConvert(final Class<?> from, final Class<?> to) { |
| return linkerServices.canConvert(from, to); |
| } |
| |
| @Override |
| public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest) throws Exception { |
| return linkerServices.getGuardedInvocation(linkRequest); |
| } |
| |
| @Override |
| public Comparison compareConversion(final Class<?> sourceType, final Class<?> targetType1, final Class<?> targetType2) { |
| if (sourceType == ConsString.class) { |
| if (String.class == targetType1 || CharSequence.class == targetType1) { |
| return Comparison.TYPE_1_BETTER; |
| } |
| |
| if (String.class == targetType2 || CharSequence.class == targetType2) { |
| return Comparison.TYPE_2_BETTER; |
| } |
| } |
| return linkerServices.compareConversion(sourceType, targetType1, targetType2); |
| } |
| |
| @Override |
| public MethodHandle filterInternalObjects(final MethodHandle target) { |
| return linkerServices.filterInternalObjects(target); |
| } |
| |
| @Override |
| public <T> T getWithLookup(final Supplier<T> operation, final SecureLookupSupplier lookupSupplier) { |
| return linkerServices.getWithLookup(operation, lookupSupplier); |
| } |
| } |
| } |