NashornBeansLinker.java revision 1477:dd36e980905b
1109998Smarkm/* 2194206Ssimon * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3109998Smarkm * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4109998Smarkm * 5109998Smarkm * This code is free software; you can redistribute it and/or modify it 6238405Sjkim * under the terms of the GNU General Public License version 2 only, as 7109998Smarkm * published by the Free Software Foundation. Oracle designates this 8109998Smarkm * particular file as subject to the "Classpath" exception as provided 9109998Smarkm * by Oracle in the LICENSE file that accompanied this code. 10109998Smarkm * 11109998Smarkm * This code is distributed in the hope that it will be useful, but WITHOUT 12109998Smarkm * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13109998Smarkm * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14109998Smarkm * version 2 for more details (a copy is included in the LICENSE file that 15109998Smarkm * accompanied this code). 16109998Smarkm * 17109998Smarkm * You should have received a copy of the GNU General Public License version 18109998Smarkm * 2 along with this work; if not, write to the Free Software Foundation, 19109998Smarkm * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20109998Smarkm * 21109998Smarkm * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22109998Smarkm * or visit www.oracle.com if you need additional information or have any 23109998Smarkm * questions. 24109998Smarkm */ 25109998Smarkm 26109998Smarkmpackage jdk.nashorn.internal.runtime.linker; 27109998Smarkm 28109998Smarkmimport static jdk.nashorn.internal.lookup.Lookup.MH; 29109998Smarkm 30109998Smarkmimport java.lang.invoke.MethodHandle; 31109998Smarkmimport java.lang.invoke.MethodHandles; 32109998Smarkmimport java.lang.invoke.MethodType; 33109998Smarkmimport java.lang.reflect.Method; 34109998Smarkmimport java.lang.reflect.Modifier; 35109998Smarkmimport jdk.internal.dynalink.CallSiteDescriptor; 36109998Smarkmimport jdk.internal.dynalink.beans.BeansLinker; 37109998Smarkmimport jdk.internal.dynalink.linker.ConversionComparator.Comparison; 38109998Smarkmimport jdk.internal.dynalink.linker.GuardedInvocation; 39109998Smarkmimport jdk.internal.dynalink.linker.GuardingDynamicLinker; 40109998Smarkmimport jdk.internal.dynalink.linker.LinkRequest; 41109998Smarkmimport jdk.internal.dynalink.linker.LinkerServices; 42109998Smarkmimport jdk.internal.dynalink.linker.MethodHandleTransformer; 43109998Smarkmimport jdk.internal.dynalink.linker.support.DefaultInternalObjectFilter; 44109998Smarkmimport jdk.internal.dynalink.linker.support.Lookup; 45109998Smarkmimport jdk.nashorn.api.scripting.ScriptUtils; 46109998Smarkmimport jdk.nashorn.internal.runtime.ConsString; 47109998Smarkmimport jdk.nashorn.internal.runtime.Context; 48109998Smarkmimport jdk.nashorn.internal.runtime.ScriptObject; 49109998Smarkmimport jdk.nashorn.internal.runtime.options.Options; 50109998Smarkm 51109998Smarkm/** 52109998Smarkm * This linker delegates to a {@code BeansLinker} but passes it a special linker services object that has a modified 53109998Smarkm * {@code compareConversion} method that favors conversion of {@link ConsString} to either {@link String} or 54109998Smarkm * {@link CharSequence}. It also provides a {@link #createHiddenObjectFilter()} method for use with bootstrap that will 55109998Smarkm * ensure that we never pass internal engine objects that should not be externally observable (currently ConsString and 56109998Smarkm * ScriptObject) to Java APIs, but rather that we flatten it into a String. We can't just add this functionality as 57109998Smarkm * custom converters via {@code GuaardingTypeConverterFactory}, since they are not consulted when 5855714Skris * the target method handle parameter signature is {@code Object}. This linker also makes sure that primitive 5955714Skris * {@link String} operations can be invoked on a {@link ConsString}, and allows invocation of objects implementing 6055714Skris * the {@link FunctionalInterface} attribute. 6155714Skris */ 6255714Skrispublic class NashornBeansLinker implements GuardingDynamicLinker { 63109998Smarkm // System property to control whether to wrap ScriptObject->ScriptObjectMirror for 64205128Ssimon // Object type arguments of Java method calls, field set and array set. 6555714Skris private static final boolean MIRROR_ALWAYS = Options.getBooleanProperty("nashorn.mirror.always", true); 66109998Smarkm 67238405Sjkim private static final MethodHandle EXPORT_ARGUMENT; 68238405Sjkim private static final MethodHandle IMPORT_RESULT; 6955714Skris private static final MethodHandle FILTER_CONSSTRING; 70109998Smarkm 71109998Smarkm static { 72109998Smarkm final Lookup lookup = new Lookup(MethodHandles.lookup()); 73238405Sjkim EXPORT_ARGUMENT = lookup.findOwnStatic("exportArgument", Object.class, Object.class); 74238405Sjkim IMPORT_RESULT = lookup.findOwnStatic("importResult", Object.class, Object.class); 75238405Sjkim FILTER_CONSSTRING = lookup.findOwnStatic("consStringFilter", Object.class, Object.class); 76238405Sjkim } 77238405Sjkim 78109998Smarkm // cache of @FunctionalInterface method of implementor classes 79109998Smarkm private static final ClassValue<String> FUNCTIONAL_IFACE_METHOD_NAME = new ClassValue<String>() { 80109998Smarkm @Override 81238405Sjkim protected String computeValue(final Class<?> type) { 82109998Smarkm return findFunctionalInterfaceMethodName(type); 83109998Smarkm } 8455714Skris }; 8555714Skris 86109998Smarkm private final BeansLinker beansLinker = new BeansLinker(); 87109998Smarkm 88109998Smarkm @Override 89109998Smarkm public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { 90109998Smarkm final Object self = linkRequest.getReceiver(); 91238405Sjkim final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor(); 92109998Smarkm if (self instanceof ConsString) { 93109998Smarkm // In order to treat ConsString like a java.lang.String we need a link request with a string receiver. 94238405Sjkim final Object[] arguments = linkRequest.getArguments(); 95238405Sjkim arguments[0] = ""; 9655714Skris final LinkRequest forgedLinkRequest = linkRequest.replaceArguments(desc, arguments); 97109998Smarkm final GuardedInvocation invocation = getGuardedInvocation(beansLinker, forgedLinkRequest, linkerServices); 98109998Smarkm // If an invocation is found we add a filter that makes it work for both Strings and ConsStrings. 99109998Smarkm return invocation == null ? null : invocation.filterArguments(0, FILTER_CONSSTRING); 100109998Smarkm } 101109998Smarkm 102109998Smarkm if (self != null && "call".equals(desc.getNameToken(CallSiteDescriptor.OPERATOR))) { 103109998Smarkm // Support dyn:call on any object that supports some @FunctionalInterface 104109998Smarkm // annotated interface. This way Java method, constructor references or 105109998Smarkm // implementations of java.util.function.* interfaces can be called as though 106109998Smarkm // those are script functions. 10755714Skris final String name = getFunctionalInterfaceMethodName(self.getClass()); 10855714Skris if (name != null) { 109109998Smarkm final MethodType callType = desc.getMethodType(); 110109998Smarkm // drop callee (Undefined ScriptFunction) and change the request to be dyn:callMethod:<name> 111109998Smarkm final NashornCallSiteDescriptor newDesc = NashornCallSiteDescriptor.get( 112109998Smarkm NashornCallSiteDescriptor.getLookupPrivileged(desc), "dyn:callMethod:" + name, 113109998Smarkm desc.getMethodType().dropParameterTypes(1, 2), 114109998Smarkm NashornCallSiteDescriptor.getFlags(desc)); 115109998Smarkm final GuardedInvocation gi = getGuardedInvocation(beansLinker, 116109998Smarkm linkRequest.replaceArguments(newDesc, linkRequest.getArguments()), 11755714Skris new NashornBeansLinkerServices(linkerServices)); 118109998Smarkm 11955714Skris // drop 'thiz' passed from the script. 120109998Smarkm return gi.replaceMethods( 121109998Smarkm MH.dropArguments(linkerServices.filterInternalObjects(gi.getInvocation()), 1, callType.parameterType(1)), 122109998Smarkm gi.getGuard()); 123109998Smarkm } 124109998Smarkm } 12555714Skris return getGuardedInvocation(beansLinker, linkRequest, linkerServices); 126109998Smarkm } 12755714Skris 128109998Smarkm /** 129109998Smarkm * Delegates to the specified linker but injects its linker services wrapper so that it will apply all special 130109998Smarkm * conversions that this class does. 131109998Smarkm * @param delegateLinker the linker to which the actual work is delegated to. 132109998Smarkm * @param linkRequest the delegated link request 13355714Skris * @param linkerServices the original link services that will be augmented with special conversions 134109998Smarkm * @return the guarded invocation from the delegate, possibly augmented with special conversions 135109998Smarkm * @throws Exception if the delegate throws an exception 136109998Smarkm */ 137109998Smarkm public static GuardedInvocation getGuardedInvocation(final GuardingDynamicLinker delegateLinker, final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { 138109998Smarkm return delegateLinker.getGuardedInvocation(linkRequest, new NashornBeansLinkerServices(linkerServices)); 139109998Smarkm } 14055714Skris 141109998Smarkm @SuppressWarnings("unused") 142109998Smarkm private static Object exportArgument(final Object arg) { 143109998Smarkm return exportArgument(arg, MIRROR_ALWAYS); 144109998Smarkm } 145109998Smarkm 146109998Smarkm static Object exportArgument(final Object arg, final boolean mirrorAlways) { 147194206Ssimon if (arg instanceof ConsString) { 148238405Sjkim return arg.toString(); 149238405Sjkim } else if (mirrorAlways && arg instanceof ScriptObject) { 150238405Sjkim return ScriptUtils.wrap((ScriptObject)arg); 151238405Sjkim } else { 152238405Sjkim return arg; 153194206Ssimon } 154194206Ssimon } 155194206Ssimon 156194206Ssimon @SuppressWarnings("unused") 157205128Ssimon private static Object importResult(final Object arg) { 158194206Ssimon return ScriptUtils.unwrap(arg); 159194206Ssimon } 160194206Ssimon 161194206Ssimon @SuppressWarnings("unused") 162194206Ssimon private static Object consStringFilter(final Object arg) { 163194206Ssimon return arg instanceof ConsString ? arg.toString() : arg; 164194206Ssimon } 165194206Ssimon 166194206Ssimon private static String findFunctionalInterfaceMethodName(final Class<?> clazz) { 167194206Ssimon if (clazz == null) { 168194206Ssimon return null; 169194206Ssimon } 170194206Ssimon 171194206Ssimon for (final Class<?> iface : clazz.getInterfaces()) { 172194206Ssimon // check accessibility up-front 173194206Ssimon if (! Context.isAccessibleClass(iface)) { 174194206Ssimon continue; 175194206Ssimon } 176194206Ssimon 177194206Ssimon // check for @FunctionalInterface 178194206Ssimon if (iface.isAnnotationPresent(FunctionalInterface.class)) { 179194206Ssimon // return the first abstract method 180194206Ssimon for (final Method m : iface.getMethods()) { 181194206Ssimon if (Modifier.isAbstract(m.getModifiers())) { 182194206Ssimon return m.getName(); 183194206Ssimon } 184194206Ssimon } 185194206Ssimon } 186194206Ssimon } 187194206Ssimon 188194206Ssimon // did not find here, try super class 189 return findFunctionalInterfaceMethodName(clazz.getSuperclass()); 190 } 191 192 // Returns @FunctionalInterface annotated interface's single abstract 193 // method name. If not found, returns null. 194 static String getFunctionalInterfaceMethodName(final Class<?> clazz) { 195 return FUNCTIONAL_IFACE_METHOD_NAME.get(clazz); 196 } 197 198 static MethodHandleTransformer createHiddenObjectFilter() { 199 return new DefaultInternalObjectFilter(EXPORT_ARGUMENT, MIRROR_ALWAYS ? IMPORT_RESULT : null); 200 } 201 202 private static class NashornBeansLinkerServices implements LinkerServices { 203 private final LinkerServices linkerServices; 204 205 NashornBeansLinkerServices(final LinkerServices linkerServices) { 206 this.linkerServices = linkerServices; 207 } 208 209 @Override 210 public MethodHandle asType(final MethodHandle handle, final MethodType fromType) { 211 return linkerServices.asType(handle, fromType); 212 } 213 214 @Override 215 public MethodHandle getTypeConverter(final Class<?> sourceType, final Class<?> targetType) { 216 return linkerServices.getTypeConverter(sourceType, targetType); 217 } 218 219 @Override 220 public boolean canConvert(final Class<?> from, final Class<?> to) { 221 return linkerServices.canConvert(from, to); 222 } 223 224 @Override 225 public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest) throws Exception { 226 return linkerServices.getGuardedInvocation(linkRequest); 227 } 228 229 @Override 230 public Comparison compareConversion(final Class<?> sourceType, final Class<?> targetType1, final Class<?> targetType2) { 231 if (sourceType == ConsString.class) { 232 if (String.class == targetType1 || CharSequence.class == targetType1) { 233 return Comparison.TYPE_1_BETTER; 234 } 235 236 if (String.class == targetType2 || CharSequence.class == targetType2) { 237 return Comparison.TYPE_2_BETTER; 238 } 239 } 240 return linkerServices.compareConversion(sourceType, targetType1, targetType2); 241 } 242 243 @Override 244 public MethodHandle filterInternalObjects(final MethodHandle target) { 245 return linkerServices.filterInternalObjects(target); 246 } 247 } 248} 249