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  */

    25 

    26 /*

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

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

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

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

    31  * license:

    32  */

    33 /*

    34    Copyright 2009-2013 Attila Szegedi

    35 

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

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

    38    choose either of the two at their discretion.

    39 

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

    41    License or the BSD License.

    42 

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

    44    following notice applies to you:

    45 

    46        You may obtain a copy of the Apache License at

    47 

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

    49 

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

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

    52        WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or

    53        implied. See the License for the specific language governing

    54        permissions and limitations under the License.

    55 

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

    57    following notice applies to you:

    58 

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

    60        modification, are permitted provided that the following conditions are

    61        met:

    62        * Redistributions of source code must retain the above copyright

    63          notice, this list of conditions and the following disclaimer.

    64        * Redistributions in binary form must reproduce the above copyright

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

    66          documentation and/or other materials provided with the distribution.

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

    68          contributors may be used to endorse or promote products derived from

    69          this software without specific prior written permission.

    70 

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

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

    73        TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A

    74        PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER

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

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

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

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

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

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

    81        ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    82 */

    83 

    84 package jdk.internal.dynalink.linker.support;

    85 

    86 import java.lang.invoke.MethodHandle;

    87 import java.lang.invoke.MethodHandles;

    88 import java.lang.invoke.MethodType;

    89 import java.lang.reflect.Constructor;

    90 import java.lang.reflect.Field;

    91 import java.lang.reflect.Method;

    92 

    93 /**

    94  * A wrapper around {@link java.lang.invoke.MethodHandles.Lookup} that masks

    95  * checked exceptions. It is useful in those cases when you're looking up

    96  * methods within your own codebase (therefore it is an error if they are not

    97  * present).

    98  */

    99 public final class Lookup {

   100     private final MethodHandles.Lookup lookup;

   101 

   102     /**

   103      * Creates a new instance, bound to an instance of

   104      * {@link java.lang.invoke.MethodHandles.Lookup}.

   105      *

   106      * @param lookup the {@link java.lang.invoke.MethodHandles.Lookup} it delegates to.

   107      */

   108     public Lookup(final MethodHandles.Lookup lookup) {

   109         this.lookup = lookup;

   110     }

   111 

   112     /**

   113      * A canonical Lookup object that wraps {@link MethodHandles#publicLookup()}.

   114      */

   115     public static final Lookup PUBLIC = new Lookup(MethodHandles.publicLookup());

   116 

   117     /**

   118      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflect(Method)},

   119      * converting any encountered {@link IllegalAccessException} into an

   120      * {@link IllegalAccessError}.

   121      *

   122      * @param m the method to unreflect

   123      * @return the unreflected method handle.

   124      * @throws IllegalAccessError if the method is inaccessible.

   125      */

   126     public MethodHandle unreflect(final Method m) {

   127         return unreflect(lookup, m);

   128     }

   129 

   130     /**

   131      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflect(Method)},

   132      * converting any encountered {@link IllegalAccessException} into an

   133      * {@link IllegalAccessError}.

   134      *

   135      * @param lookup the lookup used to unreflect

   136      * @param m the method to unreflect

   137      * @return the unreflected method handle.

   138      * @throws IllegalAccessError if the method is inaccessible.

   139      */

   140     public static MethodHandle unreflect(final MethodHandles.Lookup lookup, final Method m) {

   141         try {

   142             return lookup.unreflect(m);

   143         } catch(final IllegalAccessException e) {

   144             final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect method " + m);

   145             ee.initCause(e);

   146             throw ee;

   147         }

   148     }

   149 

   150     /**

   151      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectGetter(Field)},

   152      * converting any encountered {@link IllegalAccessException} into an {@link IllegalAccessError}.

   153      *

   154      * @param f the field for which a getter is unreflected

   155      * @return the unreflected field getter handle.

   156      * @throws IllegalAccessError if the getter is inaccessible.

   157      */

   158     public MethodHandle unreflectGetter(final Field f) {

   159         try {

   160             return lookup.unreflectGetter(f);

   161         } catch(final IllegalAccessException e) {

   162             final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect getter for field " + f);

   163             ee.initCause(e);

   164             throw ee;

   165         }

   166     }

   167 

   168     /**

   169      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findGetter(Class, String, Class)},

   170      * converting any encountered {@link IllegalAccessException} into an

   171      * {@link IllegalAccessError} and {@link NoSuchFieldException} into a

   172      * {@link NoSuchFieldError}.

   173      *

   174      * @param refc the class declaring the field

   175      * @param name the name of the field

   176      * @param type the type of the field

   177      * @return the unreflected field getter handle.

   178      * @throws IllegalAccessError if the field is inaccessible.

   179      * @throws NoSuchFieldError if the field does not exist.

   180      */

   181     public MethodHandle findGetter(final Class<?>refc, final String name, final Class<?> type) {

   182         try {

   183             return lookup.findGetter(refc, name, type);

   184         } catch(final IllegalAccessException e) {

   185             final IllegalAccessError ee = new IllegalAccessError("Failed to access getter for field " + refc.getName() +

   186                     "." + name + " of type " + type.getName());

   187             ee.initCause(e);

   188             throw ee;

   189         } catch(final NoSuchFieldException e) {

   190             final NoSuchFieldError ee = new NoSuchFieldError("Failed to find getter for field " + refc.getName() +

   191                     "." + name + " of type " + type.getName());

   192             ee.initCause(e);

   193             throw ee;

   194         }

   195     }

   196 

   197     /**

   198      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectSetter(Field)},

   199      * converting any encountered {@link IllegalAccessException} into an

   200      * {@link IllegalAccessError}.

   201      *

   202      * @param f the field for which a setter is unreflected

   203      * @return the unreflected field setter handle.

   204      * @throws IllegalAccessError if the field is inaccessible.

   205      * @throws NoSuchFieldError if the field does not exist.

   206      */

   207     public MethodHandle unreflectSetter(final Field f) {

   208         try {

   209             return lookup.unreflectSetter(f);

   210         } catch(final IllegalAccessException e) {

   211             final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect setter for field " + f);

   212             ee.initCause(e);

   213             throw ee;

   214         }

   215     }

   216 

   217     /**

   218      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectConstructor(Constructor)},

   219      * converting any encountered {@link IllegalAccessException} into an

   220      * {@link IllegalAccessError}.

   221      *

   222      * @param c the constructor to unreflect

   223      * @return the unreflected constructor handle.

   224      * @throws IllegalAccessError if the constructor is inaccessible.

   225      */

   226     public MethodHandle unreflectConstructor(final Constructor<?> c) {

   227         return unreflectConstructor(lookup, c);

   228     }

   229 

   230     /**

   231      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectConstructor(Constructor)},

   232      * converting any encountered {@link IllegalAccessException} into an

   233      * {@link IllegalAccessError}.

   234      *

   235      * @param lookup the lookup used to unreflect

   236      * @param c the constructor to unreflect

   237      * @return the unreflected constructor handle.

   238      * @throws IllegalAccessError if the constructor is inaccessible.

   239      */

   240     public static MethodHandle unreflectConstructor(final MethodHandles.Lookup lookup, final Constructor<?> c) {

   241         try {

   242             return lookup.unreflectConstructor(c);

   243         } catch(final IllegalAccessException e) {

   244             final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect constructor " + c);

   245             ee.initCause(e);

   246             throw ee;

   247         }

   248     }

   249 

   250     /**

   251      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findSpecial(Class, String, MethodType, Class)}

   252      * on the underlying lookup. Converts any encountered

   253      * {@link IllegalAccessException} into an {@link IllegalAccessError} and

   254      * {@link NoSuchMethodException} into a {@link NoSuchMethodError}.

   255      *

   256      * @param declaringClass class declaring the method

   257      * @param name the name of the method

   258      * @param type the type of the method

   259      * @return a method handle for the method

   260      * @throws IllegalAccessError if the method is inaccessible.

   261      * @throws NoSuchMethodError if the method does not exist.

   262      */

   263     public MethodHandle findSpecial(final Class<?> declaringClass, final String name, final MethodType type) {

   264         try {

   265             return lookup.findSpecial(declaringClass, name, type, declaringClass);

   266         } catch(final IllegalAccessException e) {

   267             final IllegalAccessError ee = new IllegalAccessError("Failed to access special method " + methodDescription(

   268                     declaringClass, name, type));

   269             ee.initCause(e);

   270             throw ee;

   271         } catch(final NoSuchMethodException e) {

   272             final NoSuchMethodError ee = new NoSuchMethodError("Failed to find special method " + methodDescription(

   273                     declaringClass, name, type));

   274             ee.initCause(e);

   275             throw ee;

   276         }

   277     }

   278 

   279     private static String methodDescription(final Class<?> declaringClass, final String name, final MethodType type) {

   280         return declaringClass.getName() + "#" + name + type;

   281     }

   282 

   283     /**

   284      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findStatic(Class, String, MethodType)}

   285      * on the underlying lookup. Converts any encountered

   286      * {@link IllegalAccessException} into an {@link IllegalAccessError} and

   287      * {@link NoSuchMethodException} into a {@link NoSuchMethodError}.

   288      *

   289      * @param declaringClass class declaring the method

   290      * @param name the name of the method

   291      * @param type the type of the method

   292      * @return a method handle for the method

   293      * @throws IllegalAccessError if the method is inaccessible.

   294      * @throws NoSuchMethodError if the method does not exist.

   295      */

   296     public MethodHandle findStatic(final Class<?> declaringClass, final String name, final MethodType type) {

   297         try {

   298             return lookup.findStatic(declaringClass, name, type);

   299         } catch(final IllegalAccessException e) {

   300             final IllegalAccessError ee = new IllegalAccessError("Failed to access static method " + methodDescription(

   301                     declaringClass, name, type));

   302             ee.initCause(e);

   303             throw ee;

   304         } catch(final NoSuchMethodException e) {

   305             final NoSuchMethodError ee = new NoSuchMethodError("Failed to find static method " + methodDescription(

   306                     declaringClass, name, type));

   307             ee.initCause(e);

   308             throw ee;

   309         }

   310     }

   311 

   312     /**

   313      * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findVirtual(Class, String, MethodType)}

   314      * on the underlying lookup. Converts any encountered

   315      * {@link IllegalAccessException} into an {@link IllegalAccessError} and

   316      * {@link NoSuchMethodException} into a {@link NoSuchMethodError}.

   317      *

   318      * @param declaringClass class declaring the method

   319      * @param name the name of the method

   320      * @param type the type of the method

   321      * @return a method handle for the method

   322      * @throws IllegalAccessError if the method is inaccessible.

   323      * @throws NoSuchMethodError if the method does not exist.

   324      */

   325     public MethodHandle findVirtual(final Class<?> declaringClass, final String name, final MethodType type) {

   326         try {

   327             return lookup.findVirtual(declaringClass, name, type);

   328         } catch(final IllegalAccessException e) {

   329             final IllegalAccessError ee = new IllegalAccessError("Failed to access virtual method " + methodDescription(

   330                     declaringClass, name, type));

   331             ee.initCause(e);

   332             throw ee;

   333         } catch(final NoSuchMethodException e) {

   334             final NoSuchMethodError ee = new NoSuchMethodError("Failed to find virtual method " + methodDescription(

   335                     declaringClass, name, type));

   336             ee.initCause(e);

   337             throw ee;

   338         }

   339     }

   340 

   341     /**

   342      * Given a lookup, finds using {@link #findSpecial(Class, String, MethodType)}

   343      * a method on that lookup's class. Useful in classes' code for convenient

   344      * linking to their own privates.

   345      * @param lookup the lookup for the class

   346      * @param name the name of the method

   347      * @param rtype the return type of the method

   348      * @param ptypes the parameter types of the method

   349      * @return the method handle for the method

   350      */

   351     public static MethodHandle findOwnSpecial(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes) {

   352         return new Lookup(lookup).findOwnSpecial(name, rtype, ptypes);

   353     }

   354 

   355 

   356     /**

   357      * Finds using {@link #findSpecial(Class, String, MethodType)} a method on

   358      * that lookup's class. Useful in classes' code for convenient linking to

   359      * their own privates. It's also more convenient than {@code findSpecial}

   360      * in that you can just list the parameter types, and don't have to specify

   361      * lookup class.

   362      * @param name the name of the method

   363      * @param rtype the return type of the method

   364      * @param ptypes the parameter types of the method

   365      * @return the method handle for the method

   366      */

   367     public MethodHandle findOwnSpecial(final String name, final Class<?> rtype, final Class<?>... ptypes) {

   368         return findSpecial(lookup.lookupClass(), name, MethodType.methodType(rtype, ptypes));

   369     }

   370 

   371     /**

   372      * Given a lookup, finds using {@link #findStatic(Class, String, MethodType)}

   373      * a method on that lookup's class. Useful in classes' code for convenient

   374      * linking to their own privates. It's easier to use than {@code findStatic}

   375      * in that you can just list the parameter types, and don't have to specify

   376      * lookup class.

   377      * @param lookup the lookup for the class

   378      * @param name the name of the method

   379      * @param rtype the return type of the method

   380      * @param ptypes the parameter types of the method

   381      * @return the method handle for the method

   382      */

   383     public static MethodHandle findOwnStatic(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes) {

   384         return new Lookup(lookup).findOwnStatic(name, rtype, ptypes);

   385     }

   386 

   387     /**

   388      * Finds using {@link #findStatic(Class, String, MethodType)} a method on

   389      * that lookup's class. Useful in classes' code for convenient linking to

   390      * their own privates. It's easier to use than {@code findStatic}

   391      * in that you can just list the parameter types, and don't have to specify

   392      * lookup class.

   393      * @param name the name of the method

   394      * @param rtype the return type of the method

   395      * @param ptypes the parameter types of the method

   396      * @return the method handle for the method

   397      */

   398     public MethodHandle findOwnStatic(final String name, final Class<?> rtype, final Class<?>... ptypes) {

   399         return findStatic(lookup.lookupClass(), name, MethodType.methodType(rtype, ptypes));

   400     }

   401 }