| /* |
| * 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.Modifier; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.util.Collection; |
| import java.util.Deque; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Queue; |
| import javax.script.Bindings; |
| import jdk.internal.dynalink.CallSiteDescriptor; |
| import jdk.internal.dynalink.linker.ConversionComparator; |
| import jdk.internal.dynalink.linker.GuardedInvocation; |
| import jdk.internal.dynalink.linker.GuardedTypeConversion; |
| import jdk.internal.dynalink.linker.GuardingTypeConverterFactory; |
| import jdk.internal.dynalink.linker.LinkRequest; |
| import jdk.internal.dynalink.linker.LinkerServices; |
| import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker; |
| import jdk.internal.dynalink.support.Guards; |
| import jdk.internal.dynalink.support.LinkerServicesImpl; |
| import jdk.internal.dynalink.support.Lookup; |
| import jdk.nashorn.api.scripting.JSObject; |
| import jdk.nashorn.api.scripting.ScriptObjectMirror; |
| import jdk.nashorn.api.scripting.ScriptUtils; |
| import jdk.nashorn.internal.objects.NativeArray; |
| import jdk.nashorn.internal.runtime.JSType; |
| import jdk.nashorn.internal.runtime.ListAdapter; |
| import jdk.nashorn.internal.runtime.ScriptFunction; |
| import jdk.nashorn.internal.runtime.ScriptObject; |
| import jdk.nashorn.internal.runtime.Undefined; |
| |
| /** |
| * This is the main dynamic linker for Nashorn. It is used for linking all {@link ScriptObject} and its subclasses (this |
| * includes {@link ScriptFunction} and its subclasses) as well as {@link Undefined}. |
| */ |
| final class NashornLinker implements TypeBasedGuardingDynamicLinker, GuardingTypeConverterFactory, ConversionComparator { |
| private static final ClassValue<MethodHandle> ARRAY_CONVERTERS = new ClassValue<MethodHandle>() { |
| @Override |
| protected MethodHandle computeValue(final Class<?> type) { |
| return createArrayConverter(type); |
| } |
| }; |
| |
| /** |
| * Returns true if {@code ScriptObject} is assignable from {@code type}, or it is {@code Undefined}. |
| */ |
| @Override |
| public boolean canLinkType(final Class<?> type) { |
| return canLinkTypeStatic(type); |
| } |
| |
| static boolean canLinkTypeStatic(final Class<?> type) { |
| return ScriptObject.class.isAssignableFrom(type) || Undefined.class == type; |
| } |
| |
| @Override |
| public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception { |
| final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context |
| final Object self = requestWithoutContext.getReceiver(); |
| final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor(); |
| |
| if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) { |
| // We only support standard "dyn:*[:*]" operations |
| return null; |
| } |
| |
| return Bootstrap.asTypeSafeReturn(getGuardedInvocation(self, request, desc), linkerServices, desc); |
| } |
| |
| private static GuardedInvocation getGuardedInvocation(final Object self, final LinkRequest request, final CallSiteDescriptor desc) { |
| final GuardedInvocation inv; |
| if (self instanceof ScriptObject) { |
| inv = ((ScriptObject)self).lookup(desc, request); |
| } else if (self instanceof Undefined) { |
| inv = Undefined.lookup(desc); |
| } else { |
| throw new AssertionError(self.getClass().getName()); // Should never reach here. |
| } |
| |
| return inv; |
| } |
| |
| @Override |
| public GuardedTypeConversion convertToType(final Class<?> sourceType, final Class<?> targetType) throws Exception { |
| GuardedInvocation gi = convertToTypeNoCast(sourceType, targetType); |
| if(gi != null) { |
| return new GuardedTypeConversion(gi.asType(MH.type(targetType, sourceType)), true); |
| } |
| gi = getSamTypeConverter(sourceType, targetType); |
| if(gi != null) { |
| return new GuardedTypeConversion(gi.asType(MH.type(targetType, sourceType)), false); |
| } |
| return null; |
| } |
| |
| /** |
| * Main part of the implementation of {@link GuardingTypeConverterFactory#convertToType(Class, Class)} that doesn't |
| * care about adapting the method signature; that's done by the invoking method. Returns either a built-in |
| * conversion to primitive (or primitive wrapper) Java types or to String, or a just-in-time generated converter to |
| * a SAM type (if the target type is a SAM type). |
| * @param sourceType the source type |
| * @param targetType the target type |
| * @return a guarded invocation that converts from the source type to the target type. |
| * @throws Exception if something goes wrong |
| */ |
| private static GuardedInvocation convertToTypeNoCast(final Class<?> sourceType, final Class<?> targetType) throws Exception { |
| final MethodHandle mh = JavaArgumentConverters.getConverter(targetType); |
| if (mh != null) { |
| return new GuardedInvocation(mh, canLinkTypeStatic(sourceType) ? null : IS_NASHORN_OR_UNDEFINED_TYPE); |
| } |
| |
| final GuardedInvocation arrayConverter = getArrayConverter(sourceType, targetType); |
| if(arrayConverter != null) { |
| return arrayConverter; |
| } |
| |
| return getMirrorConverter(sourceType, targetType); |
| } |
| |
| /** |
| * Returns a guarded invocation that converts from a source type that is ScriptFunction, or a subclass or a |
| * superclass of it) to a SAM type. |
| * @param sourceType the source type (presumably ScriptFunction or a subclass or a superclass of it) |
| * @param targetType the target type (presumably a SAM type) |
| * @return a guarded invocation that converts from the source type to the target SAM type. null is returned if |
| * either the source type is neither ScriptFunction, nor a subclass, nor a superclass of it, or if the target type |
| * is not a SAM type. |
| * @throws Exception if something goes wrong; generally, if there's an issue with creation of the SAM proxy type |
| * constructor. |
| */ |
| private static GuardedInvocation getSamTypeConverter(final Class<?> sourceType, final Class<?> targetType) throws Exception { |
| // If source type is more generic than ScriptFunction class, we'll need to use a guard |
| final boolean isSourceTypeGeneric = sourceType.isAssignableFrom(ScriptFunction.class); |
| |
| if ((isSourceTypeGeneric || ScriptFunction.class.isAssignableFrom(sourceType)) && isAutoConvertibleFromFunction(targetType)) { |
| final MethodHandle ctor = JavaAdapterFactory.getConstructor(ScriptFunction.class, targetType, getCurrentLookup()); |
| assert ctor != null; // if isAutoConvertibleFromFunction() returned true, then ctor must exist. |
| return new GuardedInvocation(ctor, isSourceTypeGeneric ? IS_SCRIPT_FUNCTION : null); |
| } |
| return null; |
| } |
| |
| private static java.lang.invoke.MethodHandles.Lookup getCurrentLookup() { |
| final LinkRequest currentRequest = AccessController.doPrivileged(new PrivilegedAction<LinkRequest>() { |
| @Override |
| public LinkRequest run() { |
| return LinkerServicesImpl.getCurrentLinkRequest(); |
| } |
| }); |
| return currentRequest == null ? MethodHandles.publicLookup() : currentRequest.getCallSiteDescriptor().getLookup(); |
| } |
| |
| /** |
| * Returns a guarded invocation that converts from a source type that is NativeArray to a Java array or List or |
| * Queue or Deque or Collection type. |
| * @param sourceType the source type (presumably NativeArray a superclass of it) |
| * @param targetType the target type (presumably an array type, or List or Queue, or Deque, or Collection) |
| * @return a guarded invocation that converts from the source type to the target type. null is returned if |
| * either the source type is neither NativeArray, nor a superclass of it, or if the target type is not an array |
| * type, List, Queue, Deque, or Collection. |
| */ |
| private static GuardedInvocation getArrayConverter(final Class<?> sourceType, final Class<?> targetType) { |
| final boolean isSourceTypeNativeArray = sourceType == NativeArray.class; |
| // If source type is more generic than NativeArray class, we'll need to use a guard |
| final boolean isSourceTypeGeneric = !isSourceTypeNativeArray && sourceType.isAssignableFrom(NativeArray.class); |
| |
| if (isSourceTypeNativeArray || isSourceTypeGeneric) { |
| final MethodHandle guard = isSourceTypeGeneric ? IS_NATIVE_ARRAY : null; |
| if(targetType.isArray()) { |
| return new GuardedInvocation(ARRAY_CONVERTERS.get(targetType), guard); |
| } else if(targetType == List.class) { |
| return new GuardedInvocation(TO_LIST, guard); |
| } else if(targetType == Deque.class) { |
| return new GuardedInvocation(TO_DEQUE, guard); |
| } else if(targetType == Queue.class) { |
| return new GuardedInvocation(TO_QUEUE, guard); |
| } else if(targetType == Collection.class) { |
| return new GuardedInvocation(TO_COLLECTION, guard); |
| } |
| } |
| return null; |
| } |
| |
| private static MethodHandle createArrayConverter(final Class<?> type) { |
| assert type.isArray(); |
| final MethodHandle converter = MH.insertArguments(JSType.TO_JAVA_ARRAY.methodHandle(), 1, type.getComponentType()); |
| return MH.asType(converter, converter.type().changeReturnType(type)); |
| } |
| |
| private static GuardedInvocation getMirrorConverter(final Class<?> sourceType, final Class<?> targetType) { |
| // Could've also used (targetType.isAssignableFrom(ScriptObjectMirror.class) && targetType != Object.class) but |
| // it's probably better to explicitly spell out the supported target types |
| if (targetType == Map.class || targetType == Bindings.class || targetType == JSObject.class || targetType == ScriptObjectMirror.class) { |
| if (ScriptObject.class.isAssignableFrom(sourceType)) { |
| return new GuardedInvocation(CREATE_MIRROR); |
| } else if (sourceType.isAssignableFrom(ScriptObject.class) || sourceType.isInterface()) { |
| return new GuardedInvocation(CREATE_MIRROR, IS_SCRIPT_OBJECT); |
| } |
| } |
| return null; |
| } |
| |
| private static boolean isAutoConvertibleFromFunction(final Class<?> clazz) { |
| return isAbstractClass(clazz) && !ScriptObject.class.isAssignableFrom(clazz) && |
| JavaAdapterFactory.isAutoConvertibleFromFunction(clazz); |
| } |
| |
| /** |
| * Utility method used by few other places in the code. Tests if the class has the abstract modifier and is not an |
| * array class. For some reason, array classes have the abstract modifier set in HotSpot JVM, and we don't want to |
| * treat array classes as abstract. |
| * @param clazz the inspected class |
| * @return true if the class is abstract and is not an array type. |
| */ |
| static boolean isAbstractClass(final Class<?> clazz) { |
| return Modifier.isAbstract(clazz.getModifiers()) && !clazz.isArray(); |
| } |
| |
| |
| @Override |
| public Comparison compareConversion(final Class<?> sourceType, final Class<?> targetType1, final Class<?> targetType2) { |
| if(sourceType == NativeArray.class) { |
| // Prefer those types we can convert to with just a wrapper (cheaper than Java array creation). |
| if(isArrayPreferredTarget(targetType1)) { |
| if(!isArrayPreferredTarget(targetType2)) { |
| return Comparison.TYPE_1_BETTER; |
| } |
| } else if(isArrayPreferredTarget(targetType2)) { |
| return Comparison.TYPE_2_BETTER; |
| } |
| // Then prefer Java arrays |
| if(targetType1.isArray()) { |
| if(!targetType2.isArray()) { |
| return Comparison.TYPE_1_BETTER; |
| } |
| } else if(targetType2.isArray()) { |
| return Comparison.TYPE_2_BETTER; |
| } |
| } |
| if(ScriptObject.class.isAssignableFrom(sourceType)) { |
| // Prefer interfaces |
| if(targetType1.isInterface()) { |
| if(!targetType2.isInterface()) { |
| return Comparison.TYPE_1_BETTER; |
| } |
| } else if(targetType2.isInterface()) { |
| return Comparison.TYPE_2_BETTER; |
| } |
| } |
| return Comparison.INDETERMINATE; |
| } |
| |
| private static boolean isArrayPreferredTarget(final Class<?> clazz) { |
| return clazz == List.class || clazz == Collection.class || clazz == Queue.class || clazz == Deque.class; |
| } |
| |
| private static final MethodHandle IS_SCRIPT_OBJECT = Guards.isInstance(ScriptObject.class, MH.type(Boolean.TYPE, Object.class)); |
| private static final MethodHandle IS_SCRIPT_FUNCTION = Guards.isInstance(ScriptFunction.class, MH.type(Boolean.TYPE, Object.class)); |
| private static final MethodHandle IS_NATIVE_ARRAY = Guards.isOfClass(NativeArray.class, MH.type(Boolean.TYPE, Object.class)); |
| |
| private static final MethodHandle IS_NASHORN_OR_UNDEFINED_TYPE = findOwnMH("isNashornTypeOrUndefined", Boolean.TYPE, Object.class); |
| private static final MethodHandle CREATE_MIRROR = findOwnMH("createMirror", Object.class, Object.class); |
| |
| private static final MethodHandle TO_COLLECTION; |
| private static final MethodHandle TO_DEQUE; |
| private static final MethodHandle TO_LIST; |
| private static final MethodHandle TO_QUEUE; |
| static { |
| final MethodHandle listAdapterCreate = new Lookup(MethodHandles.lookup()).findStatic( |
| ListAdapter.class, "create", MethodType.methodType(ListAdapter.class, Object.class)); |
| TO_COLLECTION = asReturning(listAdapterCreate, Collection.class); |
| TO_DEQUE = asReturning(listAdapterCreate, Deque.class); |
| TO_LIST = asReturning(listAdapterCreate, List.class); |
| TO_QUEUE = asReturning(listAdapterCreate, Queue.class); |
| } |
| |
| private static MethodHandle asReturning(final MethodHandle mh, final Class<?> nrtype) { |
| return mh.asType(mh.type().changeReturnType(nrtype)); |
| } |
| |
| @SuppressWarnings("unused") |
| private static boolean isNashornTypeOrUndefined(final Object obj) { |
| return obj instanceof ScriptObject || obj instanceof Undefined; |
| } |
| |
| @SuppressWarnings("unused") |
| private static Object createMirror(final Object obj) { |
| return obj instanceof ScriptObject? ScriptUtils.wrap((ScriptObject)obj) : obj; |
| } |
| |
| private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { |
| return MH.findStatic(MethodHandles.lookup(), NashornLinker.class, name, MH.type(rtype, types)); |
| } |
| } |
| |