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

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

  *

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

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  * 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

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

  *

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

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 /*

  * This file is available under and governed by the GNU General Public

  * License version 2 only, as published by the Free Software Foundation.

  * However, the following notice accompanied the original version of this

  * file, and Oracle licenses the original version of this file under the BSD

  * license:

  */

 /*

    Copyright 2009-2013 Attila Szegedi

    Licensed under both the Apache License, Version 2.0 (the "Apache License")

    and the BSD License (the "BSD License"), with licensee being free to

    choose either of the two at their discretion.

    You may not use this file except in compliance with either the Apache

    License or the BSD License.

    If you choose to use this file in compliance with the Apache License, the

    following notice applies to you:

        You may obtain a copy of the Apache License at

            http://www.apache.org/licenses/LICENSE-2.0

        Unless required by applicable law or agreed to in writing, software

        distributed under the License is distributed on an "AS IS" BASIS,

        WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or

        implied. See the License for the specific language governing

        permissions and limitations under the License.

    If you choose to use this file in compliance with the BSD License, the

    following notice applies to you:

        Redistribution and use in source and binary forms, with or without

        modification, are permitted provided that the following conditions are

        met:

        * Redistributions of source code must retain the above copyright

          notice, this list of conditions and the following disclaimer.

        * Redistributions in binary form must reproduce the above copyright

          notice, this list of conditions and the following disclaimer in the

          documentation and/or other materials provided with the distribution.

        * Neither the name of the copyright holder nor the names of

          contributors may be used to endorse or promote products derived from

          this software without specific prior written permission.

        THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

        IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED

        TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A

        PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER

        BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

        CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

        SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

        BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

        WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR

        OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF

        ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

 package jdk.internal.dynalink.beans;

 import java.lang.invoke.MethodHandle;

 import java.lang.invoke.MethodHandles;

 import java.lang.invoke.MethodType;

 import java.lang.reflect.Array;

 import jdk.internal.dynalink.linker.LinkerServices;

 import jdk.internal.dynalink.support.Guards;

 /**

  * A dynamic method bound to exactly one, non-overloaded Java method. Handles varargs.

  *

  * @author Attila Szegedi

  */

 class SimpleDynamicMethod extends DynamicMethod {

     private final MethodHandle target;

     /**

      * Creates a simple dynamic method with no name.

      * @param target the target method handle

      */

     SimpleDynamicMethod(MethodHandle target) {

         this(target, null);

     }

     /**

      * Creates a new simple dynamic method, with a name constructed from the class name, method name, and handle

      * signature.

      *

      * @param target the target method handle

      * @param clazz the class declaring the method

      * @param name the simple name of the method

      */

     SimpleDynamicMethod(MethodHandle target, Class<?> clazz, String name) {

         this(target, getName(target, clazz, name));

     }

     SimpleDynamicMethod(MethodHandle target, String name) {

         super(name);

         this.target = target;

     }

     private static String getName(MethodHandle target, Class<?> clazz, String name) {

         return getMethodNameWithSignature(target, getClassAndMethodName(clazz, name));

     }

     static String getMethodNameWithSignature(MethodHandle target, String methodName) {

         final String typeStr = target.type().toString();

         final int retTypeIndex = typeStr.lastIndexOf(')') + 1;

         int secondParamIndex = typeStr.indexOf(',') + 1;

         if(secondParamIndex == 0) {

             secondParamIndex = retTypeIndex - 1;

         }

         return typeStr.substring(retTypeIndex) + " " + methodName + "(" + typeStr.substring(secondParamIndex, retTypeIndex);

     }

     /**

      * Returns the target of this dynamic method

      *

      * @return the target of this dynamic method

      */

     MethodHandle getTarget() {

         return target;

     }

     @Override

     SimpleDynamicMethod getMethodForExactParamTypes(String paramTypes) {

         return typeMatchesDescription(paramTypes, target.type()) ? this : null;

     }

     @Override

     MethodHandle getInvocation(MethodType callSiteType, LinkerServices linkerServices) {

         final MethodType methodType = target.type();

         final int paramsLen = methodType.parameterCount();

         final boolean varArgs = target.isVarargsCollector();

         final MethodHandle fixTarget = varArgs ? target.asFixedArity() : target;

         final int fixParamsLen = varArgs ? paramsLen - 1 : paramsLen;

         final int argsLen = callSiteType.parameterCount();

         if(argsLen < fixParamsLen) {

             // Less actual arguments than number of fixed declared arguments; can't invoke.

             return null;

         }

         // Method handle has the same number of fixed arguments as the call site type

         if(argsLen == fixParamsLen) {

             // Method handle that matches the number of actual arguments as the number of fixed arguments

             final MethodHandle matchedMethod;

             if(varArgs) {

                 // If vararg, add a zero-length array of the expected type as the last argument to signify no variable

                 // arguments.

                 matchedMethod = MethodHandles.insertArguments(fixTarget, fixParamsLen, Array.newInstance(

                         methodType.parameterType(fixParamsLen).getComponentType(), 0));

             } else {

                 // Otherwise, just use the method

                 matchedMethod = fixTarget;

             }

             return createConvertingInvocation(matchedMethod, linkerServices, callSiteType);

         }

         // What's below only works for varargs

         if(!varArgs) {

             return null;

         }

         final Class<?> varArgType = methodType.parameterType(fixParamsLen);

         // Handle a somewhat sinister corner case: caller passes exactly one argument in the vararg position, and we

         // must handle both a prepacked vararg array as well as a genuine 1-long vararg sequence.

         if(argsLen == paramsLen) {

             final Class<?> callSiteLastArgType = callSiteType.parameterType(fixParamsLen);

             if(varArgType.isAssignableFrom(callSiteLastArgType)) {

                 // Call site signature guarantees we'll always be passed a single compatible array; just link directly

                 // to the method.

                 return createConvertingInvocation(fixTarget, linkerServices, callSiteType);

             }

             if(!linkerServices.canConvert(callSiteLastArgType, varArgType)) {

                 // Call site signature guarantees the argument can definitely not be an array (i.e. it is primitive);

                 // link immediately to a vararg-packing method handle.

                 return createConvertingInvocation(collectArguments(fixTarget, argsLen), linkerServices, callSiteType);

             }

             // Call site signature makes no guarantees that the single argument in the vararg position will be

             // compatible across all invocations. Need to insert an appropriate guard and fall back to generic vararg

             // method when it is not.

             return MethodHandles.guardWithTest(Guards.isInstance(varArgType, fixParamsLen, callSiteType),

                     createConvertingInvocation(fixTarget, linkerServices, callSiteType),

                     createConvertingInvocation(collectArguments(fixTarget, argsLen), linkerServices, callSiteType));

         }

         // Remaining case: more than one vararg.

         return createConvertingInvocation(collectArguments(fixTarget, argsLen), linkerServices, callSiteType);

     }

     @Override

     public boolean contains(MethodHandle mh) {

         return target.type().parameterList().equals(mh.type().parameterList());

     }

     /**

      * Creates a method handle out of the original target that will collect the varargs for the exact component type of

      * the varArg array. Note that this will nicely trigger language-specific type converters for exactly those varargs

      * for which it is necessary when later passed to linkerServices.convertArguments().

      *

      * @param target the original method handle

      * @param parameterCount the total number of arguments in the new method handle

      * @return a collecting method handle

      */

     static MethodHandle collectArguments(MethodHandle target, final int parameterCount) {

         final MethodType methodType = target.type();

         final int fixParamsLen = methodType.parameterCount() - 1;

         final Class<?> arrayType = methodType.parameterType(fixParamsLen);

         return target.asCollector(arrayType, parameterCount - fixParamsLen);

     }

     private static MethodHandle createConvertingInvocation(final MethodHandle sizedMethod,

             final LinkerServices linkerServices, final MethodType callSiteType) {

         return linkerServices.asType(sizedMethod, callSiteType);

     }

 }