| /* |
| * Copyright (c) 2010, 2016, 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.codegen.CompilerConstants.staticCallNoLookup; |
| import static jdk.nashorn.internal.runtime.ECMAErrors.typeError; |
| |
| import java.lang.invoke.CallSite; |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.lang.invoke.MethodHandles.Lookup; |
| import java.lang.invoke.MethodType; |
| import java.util.Collections; |
| import java.util.List; |
| import jdk.dynalink.CallSiteDescriptor; |
| import jdk.dynalink.DynamicLinker; |
| import jdk.dynalink.DynamicLinkerFactory; |
| import jdk.dynalink.beans.BeansLinker; |
| import jdk.dynalink.beans.StaticClass; |
| import jdk.dynalink.linker.GuardedInvocation; |
| import jdk.dynalink.linker.GuardingDynamicLinker; |
| import jdk.dynalink.linker.LinkRequest; |
| import jdk.dynalink.linker.LinkerServices; |
| import jdk.dynalink.linker.MethodTypeConversionStrategy; |
| import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker; |
| import jdk.dynalink.linker.support.TypeUtilities; |
| import jdk.nashorn.api.scripting.JSObject; |
| import jdk.nashorn.internal.codegen.CompilerConstants.Call; |
| import jdk.nashorn.internal.lookup.MethodHandleFactory; |
| import jdk.nashorn.internal.lookup.MethodHandleFunctionality; |
| import jdk.nashorn.internal.runtime.Context; |
| import jdk.nashorn.internal.runtime.ECMAException; |
| import jdk.nashorn.internal.runtime.JSType; |
| import jdk.nashorn.internal.runtime.OptimisticReturnFilters; |
| import jdk.nashorn.internal.runtime.ScriptFunction; |
| import jdk.nashorn.internal.runtime.ScriptRuntime; |
| |
| /** |
| * This class houses bootstrap method for invokedynamic instructions generated by compiler. |
| */ |
| public final class Bootstrap { |
| /** Reference to the seed boostrap function */ |
| public static final Call BOOTSTRAP = staticCallNoLookup(Bootstrap.class, "bootstrap", CallSite.class, Lookup.class, String.class, MethodType.class, int.class); |
| |
| private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality(); |
| |
| private static final MethodHandle VOID_TO_OBJECT = MH.constant(Object.class, ScriptRuntime.UNDEFINED); |
| |
| private static final BeansLinker beansLinker = new BeansLinker(Bootstrap::createMissingMemberHandler); |
| private static final GuardingDynamicLinker[] prioritizedLinkers; |
| private static final GuardingDynamicLinker[] fallbackLinkers; |
| |
| static { |
| final NashornBeansLinker nashornBeansLinker = new NashornBeansLinker(beansLinker); |
| prioritizedLinkers = new GuardingDynamicLinker[] { |
| new NashornLinker(), |
| new NashornPrimitiveLinker(), |
| new BoundCallableLinker(), |
| new JavaSuperAdapterLinker(beansLinker), |
| new JSObjectLinker(nashornBeansLinker), |
| new BrowserJSObjectLinker(nashornBeansLinker), |
| new ReflectionCheckLinker() |
| }; |
| fallbackLinkers = new GuardingDynamicLinker[] { |
| new NashornStaticClassLinker(beansLinker), |
| nashornBeansLinker, |
| new NashornBottomLinker() |
| }; |
| } |
| |
| // do not create me!! |
| private Bootstrap() { |
| } |
| |
| /** |
| * Returns a list of exposed nashorn dynalink linkers. |
| * |
| * @return a list of exposed nashorn dynalink linkers. |
| */ |
| public static List<GuardingDynamicLinker> getExposedLinkers() { |
| // we have to create BeansLinker without nashorn specific missing member handler! |
| // Or else, we'd return values such as 'undefined' to the external world! |
| final NashornBeansLinker nbl = new NashornBeansLinker(new BeansLinker()); |
| final JSObjectLinker linker = new JSObjectLinker(nbl); |
| return Collections.singletonList(linker); |
| } |
| |
| /** |
| * Creates a Nashorn dynamic linker with the given app class loader. |
| * @param appLoader the app class loader. It will be used to discover |
| * additional language runtime linkers (if any). |
| * @param unstableRelinkThreshold the unstable relink threshold |
| * @return a newly created dynamic linker. |
| */ |
| public static DynamicLinker createDynamicLinker(final ClassLoader appLoader, |
| final int unstableRelinkThreshold) { |
| final DynamicLinkerFactory factory = new DynamicLinkerFactory(); |
| factory.setPrioritizedLinkers(prioritizedLinkers); |
| factory.setFallbackLinkers(fallbackLinkers); |
| factory.setSyncOnRelink(true); |
| factory.setPrelinkTransformer((inv, request, linkerServices) -> { |
| final CallSiteDescriptor desc = request.getCallSiteDescriptor(); |
| return OptimisticReturnFilters.filterOptimisticReturnValue(inv, desc).asType(linkerServices, desc.getMethodType()); |
| }); |
| factory.setAutoConversionStrategy(Bootstrap::unboxReturnType); |
| factory.setInternalObjectsFilter(NashornBeansLinker.createHiddenObjectFilter()); |
| factory.setUnstableRelinkThreshold(unstableRelinkThreshold); |
| |
| // Linkers for any additional language runtimes deployed alongside Nashorn will be picked up by the factory. |
| factory.setClassLoader(appLoader); |
| return factory.createLinker(); |
| } |
| |
| /** |
| * Returns a dynamic linker for the specific Java class using beans semantics. |
| * @param clazz the Java class |
| * @return a dynamic linker for the specific Java class using beans semantics. |
| */ |
| public static TypeBasedGuardingDynamicLinker getBeanLinkerForClass(final Class<?> clazz) { |
| return beansLinker.getLinkerForClass(clazz); |
| } |
| |
| /** |
| * Returns if the given object is a "callable" |
| * @param obj object to be checked for callability |
| * @return true if the obj is callable |
| */ |
| public static boolean isCallable(final Object obj) { |
| if (obj == ScriptRuntime.UNDEFINED || obj == null) { |
| return false; |
| } |
| |
| return obj instanceof ScriptFunction || |
| isJSObjectFunction(obj) || |
| BeansLinker.isDynamicMethod(obj) || |
| obj instanceof BoundCallable || |
| isFunctionalInterfaceObject(obj) || |
| obj instanceof StaticClass; |
| } |
| |
| /** |
| * Returns true if the given object is a strict callable |
| * @param callable the callable object to be checked for strictness |
| * @return true if the obj is a strict callable, false if it is a non-strict callable. |
| * @throws ECMAException with {@code TypeError} if the object is not a callable. |
| */ |
| public static boolean isStrictCallable(final Object callable) { |
| if (callable instanceof ScriptFunction) { |
| return ((ScriptFunction)callable).isStrict(); |
| } else if (isJSObjectFunction(callable)) { |
| return ((JSObject)callable).isStrictFunction(); |
| } else if (callable instanceof BoundCallable) { |
| return isStrictCallable(((BoundCallable)callable).getCallable()); |
| } else if (BeansLinker.isDynamicMethod(callable) || |
| callable instanceof StaticClass || |
| isFunctionalInterfaceObject(callable)) { |
| return false; |
| } |
| throw notFunction(callable); |
| } |
| |
| private static ECMAException notFunction(final Object obj) { |
| return typeError("not.a.function", ScriptRuntime.safeToString(obj)); |
| } |
| |
| private static boolean isJSObjectFunction(final Object obj) { |
| return obj instanceof JSObject && ((JSObject)obj).isFunction(); |
| } |
| |
| /** |
| * Returns if the given object is a dynalink Dynamic method |
| * @param obj object to be checked |
| * @return true if the obj is a dynamic method |
| */ |
| public static boolean isDynamicMethod(final Object obj) { |
| return BeansLinker.isDynamicMethod(obj instanceof BoundCallable ? ((BoundCallable)obj).getCallable() : obj); |
| } |
| |
| /** |
| * Returns if the given object is an instance of an interface annotated with |
| * java.lang.FunctionalInterface |
| * @param obj object to be checked |
| * @return true if the obj is an instance of @FunctionalInterface interface |
| */ |
| public static boolean isFunctionalInterfaceObject(final Object obj) { |
| return !JSType.isPrimitive(obj) && (NashornBeansLinker.getFunctionalInterfaceMethodName(obj.getClass()) != null); |
| } |
| |
| /** |
| * Create a call site and link it for Nashorn. This version of the method conforms to the invokedynamic bootstrap |
| * method expected signature and is referenced from Nashorn generated bytecode as the bootstrap method for all |
| * invokedynamic instructions. |
| * @param lookup MethodHandle lookup. |
| * @param opDesc Dynalink dynamic operation descriptor. |
| * @param type Method type. |
| * @param flags flags for call type, trace/profile etc. |
| * @return CallSite with MethodHandle to appropriate method or null if not found. |
| */ |
| public static CallSite bootstrap(final Lookup lookup, final String opDesc, final MethodType type, final int flags) { |
| return Context.getDynamicLinker(lookup.lookupClass()).link(LinkerCallSite.newLinkerCallSite(lookup, opDesc, type, flags)); |
| } |
| |
| /** |
| * Returns a dynamic invoker for a specified dynamic operation using the |
| * public lookup. You can use this method to create a method handle that |
| * when invoked acts completely as if it were a Nashorn-linked call site. |
| * Note that the available operations are encoded in the flags, see |
| * {@link NashornCallSiteDescriptor} operation constants. If the operation |
| * takes a name, it should be set otherwise empty name (not null) should be |
| * used. All names (including the empty one) should be encoded using |
| * {@link NameCodec#encode(String)}. Few examples: |
| * <ul> |
| * <li>Get a named property with fixed name: |
| * <pre> |
| * MethodHandle getColor = Boostrap.createDynamicInvoker( |
| * "color", |
| * NashornCallSiteDescriptor.GET_PROPERTY, |
| * Object.class, Object.class); |
| * Object obj = ...; // somehow obtain the object |
| * Object color = getColor.invokeExact(obj); |
| * </pre> |
| * </li> |
| * <li>Get a named property with variable name: |
| * <pre> |
| * MethodHandle getProperty = Boostrap.createDynamicInvoker( |
| * NameCodec.encode(""), |
| * NashornCallSiteDescriptor.GET_PROPERTY, |
| * Object.class, Object.class, String.class); |
| * Object obj = ...; // somehow obtain the object |
| * Object color = getProperty.invokeExact(obj, "color"); |
| * Object shape = getProperty.invokeExact(obj, "shape"); |
| * |
| * MethodHandle getNumProperty = Boostrap.createDynamicInvoker( |
| * NameCodec.encode(""), |
| * NashornCallSiteDescriptor.GET_ELEMENT, |
| * Object.class, Object.class, int.class); |
| * Object elem42 = getNumProperty.invokeExact(obj, 42); |
| * </pre> |
| * </li> |
| * <li>Set a named property with fixed name: |
| * <pre> |
| * MethodHandle setColor = Boostrap.createDynamicInvoker( |
| * "color", |
| * NashornCallSiteDescriptor.SET_PROPERTY, |
| * void.class, Object.class, Object.class); |
| * Object obj = ...; // somehow obtain the object |
| * setColor.invokeExact(obj, Color.BLUE); |
| * </pre> |
| * </li> |
| * <li>Set a property with variable name: |
| * <pre> |
| * MethodHandle setProperty = Boostrap.createDynamicInvoker( |
| * NameCodec.encode(""), |
| * NashornCallSiteDescriptor.SET_PROPERTY, |
| * void.class, Object.class, String.class, Object.class); |
| * Object obj = ...; // somehow obtain the object |
| * setProperty.invokeExact(obj, "color", Color.BLUE); |
| * setProperty.invokeExact(obj, "shape", Shape.CIRCLE); |
| * </pre> |
| * </li> |
| * <li>Call a function on an object; note it's a two-step process: get the |
| * method, then invoke the method. This is the actual: |
| * <pre> |
| * MethodHandle findFooFunction = Boostrap.createDynamicInvoker( |
| * "foo", |
| * NashornCallSiteDescriptor.GET_METHOD, |
| * Object.class, Object.class); |
| * Object obj = ...; // somehow obtain the object |
| * Object foo_fn = findFooFunction.invokeExact(obj); |
| * MethodHandle callFunctionWithTwoArgs = Boostrap.createDynamicCallInvoker( |
| * Object.class, Object.class, Object.class, Object.class, Object.class); |
| * // Note: "call" operation takes a function, then a "this" value, then the arguments: |
| * Object foo_retval = callFunctionWithTwoArgs.invokeExact(foo_fn, obj, arg1, arg2); |
| * </pre> |
| * </li> |
| * </ul> |
| * Few additional remarks: |
| * <ul> |
| * <li>Just as Nashorn works with any Java object, the invokers returned |
| * from this method can also be applied to arbitrary Java objects in |
| * addition to Nashorn JavaScript objects.</li> |
| * <li>For invoking a named function on an object, you can also use the |
| * {@link InvokeByName} convenience class.</li> |
| * <li>There's no rule that the variable property identifier has to be a |
| * {@code String} for {@code GET_PROPERTY/SET_PROPERTY} and {@code int} for |
| * {@code GET_ELEMENT/SET_ELEMENT}. You can declare their type to be |
| * {@code int}, {@code double}, {@code Object}, and so on regardless of the |
| * kind of the operation.</li> |
| * <li>You can be as specific in parameter types as you want. E.g. if you |
| * know that the receiver of the operation will always be |
| * {@code ScriptObject}, you can pass {@code ScriptObject.class} as its |
| * parameter type. If you happen to link to a method that expects different |
| * types, (you can use these invokers on POJOs too, after all, and end up |
| * linking with their methods that have strongly-typed signatures), all |
| * necessary conversions allowed by either Java or JavaScript will be |
| * applied: if invoked methods specify either primitive or wrapped Java |
| * numeric types, or {@code String} or {@code boolean/Boolean}, then the |
| * parameters might be subjected to standard ECMAScript {@code ToNumber}, |
| * {@code ToString}, and {@code ToBoolean} conversion, respectively. Less |
| * obviously, if the expected parameter type is a SAM type, and you pass a |
| * JavaScript function, a proxy object implementing the SAM type and |
| * delegating to the function will be passed. Linkage can often be optimized |
| * when linkers have more specific type information than "everything can be |
| * an object".</li> |
| * <li>You can also be as specific in return types as you want. For return |
| * types any necessary type conversion available in either Java or |
| * JavaScript will be automatically applied, similar to the process |
| * described for parameters, only in reverse direction: if you specify any |
| * either primitive or wrapped Java numeric type, or {@code String} or |
| * {@code boolean/Boolean}, then the return values will be subjected to |
| * standard ECMAScript {@code ToNumber}, {@code ToString}, and |
| * {@code ToBoolean} conversion, respectively. Less obviously, if the return |
| * type is a SAM type, and the return value is a JavaScript function, a |
| * proxy object implementing the SAM type and delegating to the function |
| * will be returned.</li> |
| * </ul> |
| * @param name name at the call site. Must not be null. Must be encoded |
| * using {@link NameCodec#encode(String)}. If the operation does not take a |
| * name, use empty string (also has to be encoded). |
| * @param flags the call site flags for the operation; see |
| * {@link NashornCallSiteDescriptor} for available flags. The most important |
| * part of the flags are the ones encoding the actual operation. |
| * @param rtype the return type for the operation |
| * @param ptypes the parameter types for the operation |
| * @return MethodHandle for invoking the operation. |
| */ |
| public static MethodHandle createDynamicInvoker(final String name, final int flags, final Class<?> rtype, final Class<?>... ptypes) { |
| return bootstrap(MethodHandles.publicLookup(), name, MethodType.methodType(rtype, ptypes), flags).dynamicInvoker(); |
| } |
| |
| /** |
| * Returns a dynamic invoker for the {@link NashornCallSiteDescriptor#CALL} |
| * operation using the public lookup. |
| * @param rtype the return type for the operation |
| * @param ptypes the parameter types for the operation |
| * @return a dynamic invoker for the {@code CALL} operation. |
| */ |
| public static MethodHandle createDynamicCallInvoker(final Class<?> rtype, final Class<?>... ptypes) { |
| return createDynamicInvoker("", NashornCallSiteDescriptor.CALL, rtype, ptypes); |
| } |
| |
| /** |
| * Returns a dynamic invoker for a specified dynamic operation using the |
| * public lookup. Similar to |
| * {@link #createDynamicInvoker(String, int, Class, Class...)} but with |
| * already precomposed method type. |
| * @param name name at the call site. |
| * @param flags flags at the call site |
| * @param type the method type for the operation |
| * @return MethodHandle for invoking the operation. |
| */ |
| public static MethodHandle createDynamicInvoker(final String name, final int flags, final MethodType type) { |
| return bootstrap(MethodHandles.publicLookup(), name, type, flags).dynamicInvoker(); |
| } |
| |
| /** |
| * Binds any object Nashorn can use as a [[Callable]] to a receiver and optionally arguments. |
| * @param callable the callable to bind |
| * @param boundThis the bound "this" value. |
| * @param boundArgs the bound arguments. Can be either null or empty array to signify no arguments are bound. |
| * @return a bound callable. |
| * @throws ECMAException with {@code TypeError} if the object is not a callable. |
| */ |
| public static Object bindCallable(final Object callable, final Object boundThis, final Object[] boundArgs) { |
| if (callable instanceof ScriptFunction) { |
| return ((ScriptFunction)callable).createBound(boundThis, boundArgs); |
| } else if (callable instanceof BoundCallable) { |
| return ((BoundCallable)callable).bind(boundArgs); |
| } else if (isCallable(callable)) { |
| return new BoundCallable(callable, boundThis, boundArgs); |
| } |
| throw notFunction(callable); |
| } |
| |
| /** |
| * Creates a super-adapter for an adapter, that is, an adapter to the adapter that allows invocation of superclass |
| * methods on it. |
| * @param adapter the original adapter |
| * @return a new adapter that can be used to invoke super methods on the original adapter. |
| */ |
| public static Object createSuperAdapter(final Object adapter) { |
| return new JavaSuperAdapter(adapter); |
| } |
| |
| /** |
| * If the given class is a reflection-specific class (anything in {@code java.lang.reflect} and |
| * {@code java.lang.invoke} package, as well a {@link Class} and any subclass of {@link ClassLoader}) and there is |
| * a security manager in the system, then it checks the {@code nashorn.JavaReflection} {@code RuntimePermission}. |
| * @param clazz the class being tested |
| * @param isStatic is access checked for static members (or instance members) |
| */ |
| public static void checkReflectionAccess(final Class<?> clazz, final boolean isStatic) { |
| ReflectionCheckLinker.checkReflectionAccess(clazz, isStatic); |
| } |
| |
| /** |
| * Returns the Nashorn's internally used dynamic linker's services object. Note that in code that is processing a |
| * linking request, you will normally use the {@code LinkerServices} object passed by whatever top-level linker |
| * invoked the linking (if the call site is in Nashorn-generated code, you'll get this object anyway). You should |
| * only resort to retrieving a linker services object using this method when you need some linker services (e.g. |
| * type converter method handles) outside of a code path that is linking a call site. |
| * @return Nashorn's internal dynamic linker's services object. |
| */ |
| public static LinkerServices getLinkerServices() { |
| return Context.getDynamicLinker().getLinkerServices(); |
| } |
| |
| /** |
| * Takes a guarded invocation, and ensures its method and guard conform to the type of the call descriptor, using |
| * all type conversions allowed by the linker's services. This method is used by Nashorn's linkers as a last step |
| * before returning guarded invocations. Most of the code used to produce the guarded invocations does not make an |
| * effort to coordinate types of the methods, and so a final type adjustment before a guarded invocation is returned |
| * to the aggregating linker is the responsibility of the linkers themselves. |
| * @param inv the guarded invocation that needs to be type-converted. Can be null. |
| * @param linkerServices the linker services object providing the type conversions. |
| * @param desc the call site descriptor to whose method type the invocation needs to conform. |
| * @return the type-converted guarded invocation. If input is null, null is returned. If the input invocation |
| * already conforms to the requested type, it is returned unchanged. |
| */ |
| static GuardedInvocation asTypeSafeReturn(final GuardedInvocation inv, final LinkerServices linkerServices, final CallSiteDescriptor desc) { |
| return inv == null ? null : inv.asTypeSafeReturn(linkerServices, desc.getMethodType()); |
| } |
| |
| /** |
| * Adapts the return type of the method handle with {@code explicitCastArguments} when it is an unboxing |
| * conversion. This will ensure that nulls are unwrapped to false or 0. |
| * @param target the target method handle |
| * @param newType the desired new type. Note that this method does not adapt the method handle completely to the |
| * new type, it only adapts the return type; this is allowed as per |
| * {@link DynamicLinkerFactory#setAutoConversionStrategy(MethodTypeConversionStrategy)}, which is what this method |
| * is used for. |
| * @return the method handle with adapted return type, if it required an unboxing conversion. |
| */ |
| private static MethodHandle unboxReturnType(final MethodHandle target, final MethodType newType) { |
| final MethodType targetType = target.type(); |
| final Class<?> oldReturnType = targetType.returnType(); |
| final Class<?> newReturnType = newType.returnType(); |
| if (TypeUtilities.isWrapperType(oldReturnType)) { |
| if (newReturnType.isPrimitive()) { |
| // The contract of setAutoConversionStrategy is such that the difference between newType and targetType |
| // can only be JLS method invocation conversions. |
| assert TypeUtilities.isMethodInvocationConvertible(oldReturnType, newReturnType); |
| return MethodHandles.explicitCastArguments(target, targetType.changeReturnType(newReturnType)); |
| } |
| } else if (oldReturnType == void.class && newReturnType == Object.class) { |
| return MethodHandles.filterReturnValue(target, VOID_TO_OBJECT); |
| } |
| return target; |
| } |
| |
| private static MethodHandle createMissingMemberHandler( |
| final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { |
| if (BrowserJSObjectLinker.canLinkTypeStatic(linkRequest.getReceiver().getClass())) { |
| // Don't create missing member handlers for the browser JS objects as they |
| // have their own logic. |
| return null; |
| } |
| return NashornBottomLinker.linkMissingBeanMember(linkRequest, linkerServices); |
| } |
| } |
