1 /*

     2  * Copyright (c) 2008, 2010, 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  */

    25 

    26 package sun.dyn;

    27 

    28 import java.dyn.*;

    29 import static sun.dyn.MemberName.uncaughtException;

    30 

    31 /**

    32  * Parts of CallSite known to the JVM.

    33  * @author jrose

    34  */

    35 public class CallSiteImpl {

    36     // this implements the upcall from the JVM, MethodHandleNatives.makeDynamicCallSite:

    37     static CallSite makeSite(MethodHandle bootstrapMethod,

    38                              // Callee information:

    39                              String name, MethodType type,

    40                              // Extra arguments for BSM, if any:

    41                              Object info,

    42                              // Caller information:

    43                              MemberName callerMethod, int callerBCI) {

    44         Class<?> callerClass = callerMethod.getDeclaringClass();

    45         Object caller;

    46         if (bootstrapMethod.type().parameterType(0) == Class.class && TRANSITIONAL_BEFORE_PFD)

    47             caller = callerClass;  // remove for PFD

    48         else

    49             caller = MethodHandleImpl.IMPL_LOOKUP.in(callerClass);

    50         if (bootstrapMethod == null && TRANSITIONAL_BEFORE_PFD) {

    51             // If there is no bootstrap method, throw IncompatibleClassChangeError.

    52             // This is a valid generic error type for resolution (JLS 12.3.3).

    53             throw new IncompatibleClassChangeError

    54                 ("Class "+callerClass.getName()+" has not declared a bootstrap method for invokedynamic");

    55         }

    56         CallSite site;

    57         try {

    58             Object binding;

    59             info = maybeReBox(info);

    60             if (info == null) {

    61                 binding = bootstrapMethod.invokeGeneric(caller, name, type);

    62             } else if (!info.getClass().isArray()) {

    63                 binding = bootstrapMethod.invokeGeneric(caller, name, type, info);

    64             } else {

    65                 Object[] argv = (Object[]) info;

    66                 if (3 + argv.length > 255)

    67                     new InvokeDynamicBootstrapError("too many bootstrap method arguments");

    68                 MethodType bsmType = bootstrapMethod.type();

    69                 if (bsmType.parameterCount() == 4 && bsmType.parameterType(3) == Object[].class)

    70                     binding = bootstrapMethod.invokeGeneric(caller, name, type, argv);

    71                 else

    72                     binding = MethodHandles.spreadInvoker(bsmType, 3)

    73                         .invokeGeneric(bootstrapMethod, caller, name, type, argv);

    74             }

    75             //System.out.println("BSM for "+name+type+" => "+binding);

    76             if (binding instanceof CallSite) {

    77                 site = (CallSite) binding;

    78             } else if (binding instanceof MethodHandle && TRANSITIONAL_BEFORE_PFD) {

    79                 // Transitional!

    80                 MethodHandle target = (MethodHandle) binding;

    81                 site = new ConstantCallSite(target);

    82             } else {

    83                 throw new ClassCastException("bootstrap method failed to produce a CallSite");

    84             }

    85             if (TRANSITIONAL_BEFORE_PFD)

    86                 PRIVATE_INITIALIZE_CALL_SITE.invokeExact(site, name, type,

    87                                                          callerMethod, callerBCI);

    88             assert(site.getTarget() != null);

    89             assert(site.getTarget().type().equals(type));

    90         } catch (Throwable ex) {

    91             InvokeDynamicBootstrapError bex;

    92             if (ex instanceof InvokeDynamicBootstrapError)

    93                 bex = (InvokeDynamicBootstrapError) ex;

    94             else

    95                 bex = new InvokeDynamicBootstrapError("call site initialization exception", ex);

    96             throw bex;

    97         }

    98         return site;

    99     }

   100 

   101     private static boolean TRANSITIONAL_BEFORE_PFD = true;  // FIXME: remove for PFD

   102 

   103     private static Object maybeReBox(Object x) {

   104         if (x instanceof Integer) {

   105             int xi = (int) x;

   106             if (xi == (byte) xi)

   107                 x = xi;  // must rebox; see JLS 5.1.7

   108             return x;

   109         } else if (x instanceof Object[]) {

   110             Object[] xa = (Object[]) x;

   111             for (int i = 0; i < xa.length; i++) {

   112                 if (xa[i] instanceof Integer)

   113                     xa[i] = maybeReBox(xa[i]);

   114             }

   115             return xa;

   116         } else {

   117             return x;

   118         }

   119     }

   120 

   121     // This method is private in CallSite because it touches private fields in CallSite.

   122     // These private fields (vmmethod, vmindex) are specific to the JVM.

   123     private static final MethodHandle PRIVATE_INITIALIZE_CALL_SITE;

   124     static {

   125         try {

   126             PRIVATE_INITIALIZE_CALL_SITE =

   127             !TRANSITIONAL_BEFORE_PFD ? null :

   128             MethodHandleImpl.IMPL_LOOKUP.findVirtual(CallSite.class, "initializeFromJVM",

   129                 MethodType.methodType(void.class,

   130                                       String.class, MethodType.class,

   131                                       MemberName.class, int.class));

   132         } catch (ReflectiveOperationException ex) {

   133             throw uncaughtException(ex);

   134         }

   135     }

   136 

   137     public static void setCallSiteTarget(Access token, CallSite site, MethodHandle target) {

   138         Access.check(token);

   139         MethodHandleNatives.setCallSiteTarget(site, target);

   140     }

   141 }