1 /*

     2  * Copyright (c) 2015, 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.

     8  *

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

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

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

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

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

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

    21  * questions.

    22  */

    23 

    24 package java.lang.invoke;

    25 

    26 import java.lang.invoke.MethodHandles.Lookup;

    27 import jdk.internal.vm.annotation.DontInline;

    28 import jdk.internal.vm.annotation.ForceInline;

    29 /**

    30  * Helper class to inject into java.lang.invoke that provides access to

    31  * package-private methods in this package.

    32  */

    33 

    34 public class MethodHandleHelper {

    35 

    36     private MethodHandleHelper() { }

    37 

    38     public static final Lookup IMPL_LOOKUP = Lookup.IMPL_LOOKUP;

    39     public static final Class<?> MHN_CALL_SITE_CONTEXT_CLASS

    40             = MethodHandleNatives.CallSiteContext.class;

    41 

    42     public static void customize(MethodHandle mh) {

    43         mh.customize();

    44     }

    45 

    46     @ForceInline

    47     public static Object invokeBasicL(MethodHandle mh) throws Throwable {

    48         return mh.invokeBasic();

    49     }

    50 

    51     @ForceInline

    52     public static int invokeBasicI(MethodHandle mh) throws Throwable {

    53         return (int) mh.invokeBasic();

    54     }

    55 

    56     public static MethodHandle varargsArray(int nargs) {

    57         return MethodHandleImpl.varargsArray(nargs);

    58     }

    59 

    60     public static MethodHandle varargsArray(Class<?> arrayType, int nargs) {

    61         return MethodHandleImpl.varargsArray(arrayType, nargs);

    62     }

    63 

    64     public static LambdaForm getLambdaForm(MethodHandle mh) {

    65         return mh.form;

    66     }

    67 

    68     public static class NonInlinedReinvoker extends DelegatingMethodHandle {

    69         private final MethodHandle target;

    70 

    71         private NonInlinedReinvoker(MethodHandle target, LambdaForm lf) {

    72             super(target.type(), lf);

    73             this.target = target;

    74         }

    75         @Override

    76         public MethodHandle getTarget() {

    77             return target;

    78         }

    79 

    80         @Override

    81         public MethodHandle asTypeUncached(MethodType newType) {

    82             return asTypeCache = target.asType(newType);

    83         }

    84 

    85         public static MethodHandle make(MethodHandle target) {

    86             LambdaForm lform = DelegatingMethodHandle.makeReinvokerForm(

    87                     target, -1, DelegatingMethodHandle.class, "reinvoker.dontInline",

    88                 /*forceInline=*/false, DelegatingMethodHandle.NF_getTarget, null);

    89             return new NonInlinedReinvoker(target, lform);

    90         }

    91     }

    92 }