diff -r 62406a5c8345 -r d38d876f1654 nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/NashornBottomLinker.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/NashornBottomLinker.java Sun Aug 17 15:56:32 2014 +0100 @@ -0,0 +1,256 @@ +/* + * 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 static jdk.nashorn.internal.runtime.ECMAErrors.typeError; +import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED; + +import java.lang.invoke.MethodHandle; +import java.lang.invoke.MethodType; +import java.lang.reflect.Method; +import java.lang.reflect.Modifier; +import java.util.HashMap; +import java.util.Map; +import jdk.internal.dynalink.CallSiteDescriptor; +import jdk.internal.dynalink.beans.BeansLinker; +import jdk.internal.dynalink.linker.GuardedInvocation; +import jdk.internal.dynalink.linker.GuardedTypeConversion; +import jdk.internal.dynalink.linker.GuardingDynamicLinker; +import jdk.internal.dynalink.linker.GuardingTypeConverterFactory; +import jdk.internal.dynalink.linker.LinkRequest; +import jdk.internal.dynalink.linker.LinkerServices; +import jdk.internal.dynalink.support.Guards; +import jdk.nashorn.internal.codegen.types.Type; +import jdk.nashorn.internal.runtime.Context; +import jdk.nashorn.internal.runtime.JSType; +import jdk.nashorn.internal.runtime.ScriptRuntime; +import jdk.nashorn.internal.runtime.UnwarrantedOptimismException; + +/** + * Nashorn bottom linker; used as a last-resort catch-all linker for all linking requests that fall through all other + * linkers (see how {@link Bootstrap} class configures the dynamic linker in its static initializer). It will throw + * appropriate ECMAScript errors for attempts to invoke operations on {@code null}, link no-op property getters and + * setters for Java objects that couldn't be linked by any other linker, and throw appropriate ECMAScript errors for + * attempts to invoke arbitrary Java objects as functions or constructors. + */ +final class NashornBottomLinker implements GuardingDynamicLinker, GuardingTypeConverterFactory { + + @Override + public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) + throws Exception { + final Object self = linkRequest.getReceiver(); + + if (self == null) { + return linkNull(linkRequest); + } + + // None of the objects that can be linked by NashornLinker should ever reach here. Basically, anything below + // this point is a generic Java bean. Therefore, reaching here with a ScriptObject is a Nashorn bug. + assert isExpectedObject(self) : "Couldn't link " + linkRequest.getCallSiteDescriptor() + " for " + self.getClass().getName(); + + return linkBean(linkRequest, linkerServices); + } + + private static final MethodHandle EMPTY_PROP_GETTER = + MH.dropArguments(MH.constant(Object.class, UNDEFINED), 0, Object.class); + private static final MethodHandle EMPTY_ELEM_GETTER = + MH.dropArguments(EMPTY_PROP_GETTER, 0, Object.class); + private static final MethodHandle EMPTY_PROP_SETTER = + MH.asType(EMPTY_ELEM_GETTER, EMPTY_ELEM_GETTER.type().changeReturnType(void.class)); + private static final MethodHandle EMPTY_ELEM_SETTER = + MH.dropArguments(EMPTY_PROP_SETTER, 0, Object.class); + + private static GuardedInvocation linkBean(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { + final NashornCallSiteDescriptor desc = (NashornCallSiteDescriptor)linkRequest.getCallSiteDescriptor(); + final Object self = linkRequest.getReceiver(); + final String operator = desc.getFirstOperator(); + switch (operator) { + case "new": + if(BeansLinker.isDynamicMethod(self)) { + throw typeError("method.not.constructor", ScriptRuntime.safeToString(self)); + } + throw typeError("not.a.function", ScriptRuntime.safeToString(self)); + case "call": + // Support dyn: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 Method m = getFunctionalInterfaceMethod(self.getClass()); + if (m != null) { + final MethodType callType = desc.getMethodType(); + // 'callee' and 'thiz' passed from script + actual arguments + if (callType.parameterCount() != m.getParameterCount() + 2) { + throw typeError("no.method.matches.args", ScriptRuntime.safeToString(self)); + } + return Bootstrap.asTypeSafeReturn(new GuardedInvocation( + // drop 'thiz' passed from the script. + MH.dropArguments(desc.getLookup().unreflect(m), 1, callType.parameterType(1)), + Guards.getInstanceOfGuard(m.getDeclaringClass())), linkerServices, desc); + } + if(BeansLinker.isDynamicConstructor(self)) { + throw typeError("constructor.requires.new", ScriptRuntime.safeToString(self)); + } + if(BeansLinker.isDynamicMethod(self)) { + throw typeError("no.method.matches.args", ScriptRuntime.safeToString(self)); + } + throw typeError("not.a.function", ScriptRuntime.safeToString(self)); + case "callMethod": + case "getMethod": + throw typeError("no.such.function", getArgument(linkRequest), ScriptRuntime.safeToString(self)); + case "getProp": + case "getElem": + if(NashornCallSiteDescriptor.isOptimistic(desc)) { + throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT); + } + if (desc.getOperand() != null) { + return getInvocation(EMPTY_PROP_GETTER, self, linkerServices, desc); + } + return getInvocation(EMPTY_ELEM_GETTER, self, linkerServices, desc); + case "setProp": + case "setElem": + if (desc.getOperand() != null) { + return getInvocation(EMPTY_PROP_SETTER, self, linkerServices, desc); + } + return getInvocation(EMPTY_ELEM_SETTER, self, linkerServices, desc); + default: + break; + } + throw new AssertionError("unknown call type " + desc); + } + + @Override + public GuardedTypeConversion convertToType(final Class sourceType, final Class targetType) throws Exception { + final GuardedInvocation gi = convertToTypeNoCast(sourceType, targetType); + return gi == null ? null : new GuardedTypeConversion(gi.asType(MH.type(targetType, sourceType)), true); + } + + /** + * 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 conversion from Object to String/number/boolean (JS primitive types). + * @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 = CONVERTERS.get(targetType); + if (mh != null) { + return new GuardedInvocation(mh); + } + + return null; + } + + private static GuardedInvocation getInvocation(final MethodHandle handle, final Object self, final LinkerServices linkerServices, final CallSiteDescriptor desc) { + return Bootstrap.asTypeSafeReturn(new GuardedInvocation(handle, Guards.getClassGuard(self.getClass())), linkerServices, desc); + } + + // Used solely in an assertion to figure out if the object we get here is something we in fact expect. Objects + // linked by NashornLinker should never reach here. + private static boolean isExpectedObject(final Object obj) { + return !(NashornLinker.canLinkTypeStatic(obj.getClass())); + } + + private static GuardedInvocation linkNull(final LinkRequest linkRequest) { + final NashornCallSiteDescriptor desc = (NashornCallSiteDescriptor)linkRequest.getCallSiteDescriptor(); + final String operator = desc.getFirstOperator(); + switch (operator) { + case "new": + case "call": + throw typeError("not.a.function", "null"); + case "callMethod": + case "getMethod": + throw typeError("no.such.function", getArgument(linkRequest), "null"); + case "getProp": + case "getElem": + throw typeError("cant.get.property", getArgument(linkRequest), "null"); + case "setProp": + case "setElem": + throw typeError("cant.set.property", getArgument(linkRequest), "null"); + default: + break; + } + throw new AssertionError("unknown call type " + desc); + } + + private static final Map, MethodHandle> CONVERTERS = new HashMap<>(); + static { + CONVERTERS.put(boolean.class, JSType.TO_BOOLEAN.methodHandle()); + CONVERTERS.put(double.class, JSType.TO_NUMBER.methodHandle()); + CONVERTERS.put(int.class, JSType.TO_INTEGER.methodHandle()); + CONVERTERS.put(long.class, JSType.TO_LONG.methodHandle()); + CONVERTERS.put(String.class, JSType.TO_STRING.methodHandle()); + } + + private static String getArgument(final LinkRequest linkRequest) { + final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor(); + if (desc.getNameTokenCount() > 2) { + return desc.getNameToken(2); + } + return ScriptRuntime.safeToString(linkRequest.getArguments()[1]); + } + + // cache of @FunctionalInterface method of implementor classes + private static final ClassValue FUNCTIONAL_IFACE_METHOD = new ClassValue() { + @Override + protected Method computeValue(final Class type) { + return findFunctionalInterfaceMethod(type); + } + + private Method findFunctionalInterfaceMethod(final Class clazz) { + if (clazz == null) { + return null; + } + + for (final Class iface : clazz.getInterfaces()) { + // check accessiblity 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())) { + return m; + } + } + } + } + + // did not find here, try super class + return findFunctionalInterfaceMethod(clazz.getSuperclass()); + } + }; + + // Returns @FunctionalInterface annotated interface's single abstract + // method. If not found, returns null. + static Method getFunctionalInterfaceMethod(final Class clazz) { + return FUNCTIONAL_IFACE_METHOD.get(clazz); + } +}