jdk8-mips64-public/nashorn: src/jdk/nashorn/internal/runtime/linker/NashornBeansLinker.java@19263eb2ff0c

8081809: Missing final modifier in method parameters (nashorn code convention)
Reviewed-by: attila, lagergren

     1 /*

     2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    26 package jdk.nashorn.internal.runtime.linker;

    28 import static jdk.nashorn.internal.lookup.Lookup.MH;

    29 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;

    31 import java.lang.invoke.MethodHandle;

    32 import java.lang.invoke.MethodHandles;

    33 import java.lang.invoke.MethodType;

    34 import java.lang.reflect.Method;

    35 import java.lang.reflect.Modifier;

    36 import jdk.internal.dynalink.CallSiteDescriptor;

    37 import jdk.internal.dynalink.beans.BeansLinker;

    38 import jdk.internal.dynalink.linker.ConversionComparator.Comparison;

    39 import jdk.internal.dynalink.linker.GuardedInvocation;

    40 import jdk.internal.dynalink.linker.GuardingDynamicLinker;

    41 import jdk.internal.dynalink.linker.LinkRequest;

    42 import jdk.internal.dynalink.linker.LinkerServices;

    43 import jdk.internal.dynalink.linker.MethodHandleTransformer;

    44 import jdk.internal.dynalink.support.DefaultInternalObjectFilter;

    45 import jdk.internal.dynalink.support.Guards;

    46 import jdk.internal.dynalink.support.Lookup;

    47 import jdk.nashorn.api.scripting.ScriptUtils;

    48 import jdk.nashorn.internal.runtime.ConsString;

    49 import jdk.nashorn.internal.runtime.Context;

    50 import jdk.nashorn.internal.runtime.ScriptObject;

    51 import jdk.nashorn.internal.runtime.ScriptRuntime;

    52 import jdk.nashorn.internal.runtime.options.Options;

    54 /**

    55  * This linker delegates to a {@code BeansLinker} but passes it a special linker services object that has a modified

    56  * {@code compareConversion} method that favors conversion of {@link ConsString} to either {@link String} or

    57  * {@link CharSequence}. It also provides a {@link #createHiddenObjectFilter()} method for use with bootstrap that will

    58  * ensure that we never pass internal engine objects that should not be externally observable (currently ConsString and

    59  * ScriptObject) to Java APIs, but rather that we flatten it into a String. We can't just add this functionality as

    60  * custom converters via {@code GuaardingTypeConverterFactory}, since they are not consulted when

    61  * the target method handle parameter signature is {@code Object}. This linker also makes sure that primitive

    62  * {@link String} operations can be invoked on a {@link ConsString}, and allows invocation of objects implementing

    63  * the {@link FunctionalInterface} attribute.

    64  */

    65 public class NashornBeansLinker implements GuardingDynamicLinker {

    66     // System property to control whether to wrap ScriptObject->ScriptObjectMirror for

    67     // Object type arguments of Java method calls, field set and array set.

    68     private static final boolean MIRROR_ALWAYS = Options.getBooleanProperty("nashorn.mirror.always", true);

    70     private static final MethodHandle EXPORT_ARGUMENT;

    71     private static final MethodHandle IMPORT_RESULT;

    72     private static final MethodHandle FILTER_CONSSTRING;

    74     static {

    75         final Lookup lookup  = new Lookup(MethodHandles.lookup());

    76         EXPORT_ARGUMENT      = lookup.findOwnStatic("exportArgument", Object.class, Object.class);

    77         IMPORT_RESULT        = lookup.findOwnStatic("importResult", Object.class, Object.class);

    78         FILTER_CONSSTRING    = lookup.findOwnStatic("consStringFilter", Object.class, Object.class);

    79     }

    81     // cache of @FunctionalInterface method of implementor classes

    82     private static final ClassValue<Method> FUNCTIONAL_IFACE_METHOD = new ClassValue<Method>() {

    83         @Override

    84         protected Method computeValue(final Class<?> type) {

    85             return findFunctionalInterfaceMethod(type);

    86         }

    87     };

    89     private final BeansLinker beansLinker = new BeansLinker();

    91     @Override

    92     public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception {

    93         final Object self = linkRequest.getReceiver();

    94         final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor();

    95         if (self instanceof ConsString) {

    96             // In order to treat ConsString like a java.lang.String we need a link request with a string receiver.

    97             final Object[] arguments = linkRequest.getArguments();

    98             arguments[0] = "";

    99             final LinkRequest forgedLinkRequest = linkRequest.replaceArguments(desc, arguments);

   100             final GuardedInvocation invocation = getGuardedInvocation(beansLinker, forgedLinkRequest, linkerServices);

   101             // If an invocation is found we add a filter that makes it work for both Strings and ConsStrings.

   102             return invocation == null ? null : invocation.filterArguments(0, FILTER_CONSSTRING);

   103         }

   105         if (self != null && "call".equals(desc.getNameToken(CallSiteDescriptor.OPERATOR))) {

   106             // Support dyn:call on any object that supports some @FunctionalInterface

   107             // annotated interface. This way Java method, constructor references or

   108             // implementations of java.util.function.* interfaces can be called as though

   109             // those are script functions.

   110             final Method m = getFunctionalInterfaceMethod(self.getClass());

   111             if (m != null) {

   112                 final MethodType callType = desc.getMethodType();

   113                 // 'callee' and 'thiz' passed from script + actual arguments

   114                 if (callType.parameterCount() != m.getParameterCount() + 2) {

   115                     throw typeError("no.method.matches.args", ScriptRuntime.safeToString(self));

   116                 }

   117                 return new GuardedInvocation(

   118                         // drop 'thiz' passed from the script.

   119                         MH.dropArguments(linkerServices.filterInternalObjects(desc.getLookup().unreflect(m)), 1,

   120                                 callType.parameterType(1)), Guards.getInstanceOfGuard(

   121                                         m.getDeclaringClass())).asTypeSafeReturn(

   122                                                 new NashornBeansLinkerServices(linkerServices), callType);

   123             }

   124         }

   125         return getGuardedInvocation(beansLinker, linkRequest, linkerServices);

   126     }

   128     /**

   129      * Delegates to the specified linker but injects its linker services wrapper so that it will apply all special

   130      * conversions that this class does.

   131      * @param delegateLinker the linker to which the actual work is delegated to.

   132      * @param linkRequest the delegated link request

   133      * @param linkerServices the original link services that will be augmented with special conversions

   134      * @return the guarded invocation from the delegate, possibly augmented with special conversions

   135      * @throws Exception if the delegate throws an exception

   136      */

   137     public static GuardedInvocation getGuardedInvocation(final GuardingDynamicLinker delegateLinker, final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception {

   138         return delegateLinker.getGuardedInvocation(linkRequest, new NashornBeansLinkerServices(linkerServices));

   139     }

   141     @SuppressWarnings("unused")

   142     private static Object exportArgument(final Object arg) {

   143         return exportArgument(arg, MIRROR_ALWAYS);

   144     }

   146     static Object exportArgument(final Object arg, final boolean mirrorAlways) {

   147         if (arg instanceof ConsString) {

   148             return arg.toString();

   149         } else if (mirrorAlways && arg instanceof ScriptObject) {

   150             return ScriptUtils.wrap((ScriptObject)arg);

   151         } else {

   152             return arg;

   153         }

   154     }

   156     @SuppressWarnings("unused")

   157     private static Object importResult(final Object arg) {

   158         return ScriptUtils.unwrap(arg);

   159     }

   161     @SuppressWarnings("unused")

   162     private static Object consStringFilter(final Object arg) {

   163         return arg instanceof ConsString ? arg.toString() : arg;

   164     }

   166     private static Method findFunctionalInterfaceMethod(final Class<?> clazz) {

   167         if (clazz == null) {

   168             return null;

   169         }

   171         for (final Class<?> iface : clazz.getInterfaces()) {

   172             // check accessiblity up-front

   173             if (! Context.isAccessibleClass(iface)) {

   174                 continue;

   175             }

   177             // check for @FunctionalInterface

   178             if (iface.isAnnotationPresent(FunctionalInterface.class)) {

   179                 // return the first abstract method

   180                 for (final Method m : iface.getMethods()) {

   181                     if (Modifier.isAbstract(m.getModifiers())) {

   182                         return m;

   183                     }

   184                 }

   185             }

   186         }

   188         // did not find here, try super class

   189         return findFunctionalInterfaceMethod(clazz.getSuperclass());

   190     }

   192     // Returns @FunctionalInterface annotated interface's single abstract

   193     // method. If not found, returns null.

   194     static Method getFunctionalInterfaceMethod(final Class<?> clazz) {

   195         return FUNCTIONAL_IFACE_METHOD.get(clazz);

   196     }

   198     static MethodHandleTransformer createHiddenObjectFilter() {

   199         return new DefaultInternalObjectFilter(EXPORT_ARGUMENT, MIRROR_ALWAYS ? IMPORT_RESULT : null);

   200     }

   202     private static class NashornBeansLinkerServices implements LinkerServices {

   203         private final LinkerServices linkerServices;

   205         NashornBeansLinkerServices(final LinkerServices linkerServices) {

   206             this.linkerServices = linkerServices;

   207         }

   209         @Override

   210         public MethodHandle asType(final MethodHandle handle, final MethodType fromType) {

   211             return linkerServices.asType(handle, fromType);

   212         }

   214         @Override

   215         public MethodHandle asTypeLosslessReturn(final MethodHandle handle, final MethodType fromType) {

   216             return Implementation.asTypeLosslessReturn(this, handle, fromType);

   217         }

   219         @Override

   220         public MethodHandle getTypeConverter(final Class<?> sourceType, final Class<?> targetType) {

   221             return linkerServices.getTypeConverter(sourceType, targetType);

   222         }

   224         @Override

   225         public boolean canConvert(final Class<?> from, final Class<?> to) {

   226             return linkerServices.canConvert(from, to);

   227         }

   229         @Override

   230         public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest) throws Exception {

   231             return linkerServices.getGuardedInvocation(linkRequest);

   232         }

   234         @Override

   235         public Comparison compareConversion(final Class<?> sourceType, final Class<?> targetType1, final Class<?> targetType2) {

   236             if (sourceType == ConsString.class) {

   237                 if (String.class == targetType1 || CharSequence.class == targetType1) {

   238                     return Comparison.TYPE_1_BETTER;

   239                 }

   241                 if (String.class == targetType2 || CharSequence.class == targetType2) {

   242                     return Comparison.TYPE_2_BETTER;

   243                 }

   244             }

   245             return linkerServices.compareConversion(sourceType, targetType1, targetType2);

   246         }

   248         @Override

   249         public MethodHandle filterInternalObjects(final MethodHandle target) {

   250             return linkerServices.filterInternalObjects(target);

   251         }

   252     }

   253 }

Mercurial > jdk8-mips64-public > nashorn / file revision

src/jdk/nashorn/internal/runtime/linker/NashornBeansLinker.java@19263eb2ff0c

src/jdk/nashorn/internal/runtime/linker/NashornBeansLinker.java