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 Redistribution and use in source and binary forms, with or without 37 modification, are permitted provided that the following conditions are 38 met: 39 * Redistributions of source code must retain the above copyright 40 notice, this list of conditions and the following disclaimer. 41 * Redistributions in binary form must reproduce the above copyright 42 notice, this list of conditions and the following disclaimer in the 43 documentation and/or other materials provided with the distribution. 44 * Neither the name of the copyright holder nor the names of 45 contributors may be used to endorse or promote products derived from 46 this software without specific prior written permission. 47 48 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 49 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 50 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 51 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER 52 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 53 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 54 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 55 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 56 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 57 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 58 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 59 */ 60 61 package jdk.dynalink.linker.support; 62 63 import java.lang.invoke.MethodHandle; 64 import java.lang.invoke.MethodHandles; 65 import java.lang.invoke.MethodType; 66 import java.lang.reflect.Constructor; 67 import java.lang.reflect.Field; 68 import java.lang.reflect.Method; 69 70 /** 71 * A wrapper around {@link java.lang.invoke.MethodHandles.Lookup} that masks 72 * checked exceptions. It is useful in those cases when you're looking up 73 * methods within your own codebase (therefore it is an error if they are not 74 * present). 75 */ 76 public final class Lookup { 77 private final MethodHandles.Lookup lookup; 78 79 /** 80 * Creates a new instance, bound to an instance of 81 * {@link java.lang.invoke.MethodHandles.Lookup}. 82 * 83 * @param lookup the {@link java.lang.invoke.MethodHandles.Lookup} it delegates to. 84 */ Lookup(final MethodHandles.Lookup lookup)85 public Lookup(final MethodHandles.Lookup lookup) { 86 this.lookup = lookup; 87 } 88 89 /** 90 * A canonical Lookup object that wraps {@link MethodHandles#publicLookup()}. 91 */ 92 public static final Lookup PUBLIC = new Lookup(MethodHandles.publicLookup()); 93 94 /** 95 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflect(Method)}, 96 * converting any encountered {@link IllegalAccessException} into an 97 * {@link IllegalAccessError}. 98 * 99 * @param m the method to unreflect 100 * @return the unreflected method handle. 101 * @throws IllegalAccessError if the method is inaccessible. 102 */ unreflect(final Method m)103 public MethodHandle unreflect(final Method m) { 104 return unreflect(lookup, m); 105 } 106 107 /** 108 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflect(Method)}, 109 * converting any encountered {@link IllegalAccessException} into an 110 * {@link IllegalAccessError}. 111 * 112 * @param lookup the lookup used to unreflect 113 * @param m the method to unreflect 114 * @return the unreflected method handle. 115 * @throws IllegalAccessError if the method is inaccessible. 116 */ unreflect(final MethodHandles.Lookup lookup, final Method m)117 public static MethodHandle unreflect(final MethodHandles.Lookup lookup, final Method m) { 118 try { 119 return lookup.unreflect(m); 120 } catch(final IllegalAccessException e) { 121 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect method " + m); 122 ee.initCause(e); 123 throw ee; 124 } 125 } 126 127 /** 128 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectGetter(Field)}, 129 * converting any encountered {@link IllegalAccessException} into an {@link IllegalAccessError}. 130 * 131 * @param f the field for which a getter is unreflected 132 * @return the unreflected field getter handle. 133 * @throws IllegalAccessError if the getter is inaccessible. 134 */ unreflectGetter(final Field f)135 public MethodHandle unreflectGetter(final Field f) { 136 try { 137 return lookup.unreflectGetter(f); 138 } catch(final IllegalAccessException e) { 139 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect getter for field " + f); 140 ee.initCause(e); 141 throw ee; 142 } 143 } 144 145 /** 146 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findGetter(Class, String, Class)}, 147 * converting any encountered {@link IllegalAccessException} into an 148 * {@link IllegalAccessError} and {@link NoSuchFieldException} into a 149 * {@link NoSuchFieldError}. 150 * 151 * @param refc the class declaring the field 152 * @param name the name of the field 153 * @param type the type of the field 154 * @return the unreflected field getter handle. 155 * @throws IllegalAccessError if the field is inaccessible. 156 * @throws NoSuchFieldError if the field does not exist. 157 */ findGetter(final Class<?>refc, final String name, final Class<?> type)158 public MethodHandle findGetter(final Class<?>refc, final String name, final Class<?> type) { 159 try { 160 return lookup.findGetter(refc, name, type); 161 } catch(final IllegalAccessException e) { 162 final IllegalAccessError ee = new IllegalAccessError("Failed to access getter for field " + refc.getName() + 163 "." + name + " of type " + type.getName()); 164 ee.initCause(e); 165 throw ee; 166 } catch(final NoSuchFieldException e) { 167 final NoSuchFieldError ee = new NoSuchFieldError("Failed to find getter for field " + refc.getName() + 168 "." + name + " of type " + type.getName()); 169 ee.initCause(e); 170 throw ee; 171 } 172 } 173 174 /** 175 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectSetter(Field)}, 176 * converting any encountered {@link IllegalAccessException} into an 177 * {@link IllegalAccessError}. 178 * 179 * @param f the field for which a setter is unreflected 180 * @return the unreflected field setter handle. 181 * @throws IllegalAccessError if the field is inaccessible. 182 * @throws NoSuchFieldError if the field does not exist. 183 */ unreflectSetter(final Field f)184 public MethodHandle unreflectSetter(final Field f) { 185 try { 186 return lookup.unreflectSetter(f); 187 } catch(final IllegalAccessException e) { 188 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect setter for field " + f); 189 ee.initCause(e); 190 throw ee; 191 } 192 } 193 194 /** 195 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectConstructor(Constructor)}, 196 * converting any encountered {@link IllegalAccessException} into an 197 * {@link IllegalAccessError}. 198 * 199 * @param c the constructor to unreflect 200 * @return the unreflected constructor handle. 201 * @throws IllegalAccessError if the constructor is inaccessible. 202 */ unreflectConstructor(final Constructor<?> c)203 public MethodHandle unreflectConstructor(final Constructor<?> c) { 204 return unreflectConstructor(lookup, c); 205 } 206 207 /** 208 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectConstructor(Constructor)}, 209 * converting any encountered {@link IllegalAccessException} into an 210 * {@link IllegalAccessError}. 211 * 212 * @param lookup the lookup used to unreflect 213 * @param c the constructor to unreflect 214 * @return the unreflected constructor handle. 215 * @throws IllegalAccessError if the constructor is inaccessible. 216 */ unreflectConstructor(final MethodHandles.Lookup lookup, final Constructor<?> c)217 public static MethodHandle unreflectConstructor(final MethodHandles.Lookup lookup, final Constructor<?> c) { 218 try { 219 return lookup.unreflectConstructor(c); 220 } catch(final IllegalAccessException e) { 221 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect constructor " + c); 222 ee.initCause(e); 223 throw ee; 224 } 225 } 226 227 /** 228 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findSpecial(Class, String, MethodType, Class)} 229 * on the underlying lookup. Converts any encountered 230 * {@link IllegalAccessException} into an {@link IllegalAccessError} and 231 * {@link NoSuchMethodException} into a {@link NoSuchMethodError}. 232 * 233 * @param declaringClass class declaring the method 234 * @param name the name of the method 235 * @param type the type of the method 236 * @return a method handle for the method 237 * @throws IllegalAccessError if the method is inaccessible. 238 * @throws NoSuchMethodError if the method does not exist. 239 */ findSpecial(final Class<?> declaringClass, final String name, final MethodType type)240 public MethodHandle findSpecial(final Class<?> declaringClass, final String name, final MethodType type) { 241 try { 242 return lookup.findSpecial(declaringClass, name, type, declaringClass); 243 } catch(final IllegalAccessException e) { 244 final IllegalAccessError ee = new IllegalAccessError("Failed to access special method " + methodDescription( 245 declaringClass, name, type)); 246 ee.initCause(e); 247 throw ee; 248 } catch(final NoSuchMethodException e) { 249 final NoSuchMethodError ee = new NoSuchMethodError("Failed to find special method " + methodDescription( 250 declaringClass, name, type)); 251 ee.initCause(e); 252 throw ee; 253 } 254 } 255 methodDescription(final Class<?> declaringClass, final String name, final MethodType type)256 private static String methodDescription(final Class<?> declaringClass, final String name, final MethodType type) { 257 return declaringClass.getName() + "#" + name + type; 258 } 259 260 /** 261 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findStatic(Class, String, MethodType)} 262 * on the underlying lookup. Converts any encountered 263 * {@link IllegalAccessException} into an {@link IllegalAccessError} and 264 * {@link NoSuchMethodException} into a {@link NoSuchMethodError}. 265 * 266 * @param declaringClass class declaring the method 267 * @param name the name of the method 268 * @param type the type of the method 269 * @return a method handle for the method 270 * @throws IllegalAccessError if the method is inaccessible. 271 * @throws NoSuchMethodError if the method does not exist. 272 */ findStatic(final Class<?> declaringClass, final String name, final MethodType type)273 public MethodHandle findStatic(final Class<?> declaringClass, final String name, final MethodType type) { 274 try { 275 return lookup.findStatic(declaringClass, name, type); 276 } catch(final IllegalAccessException e) { 277 final IllegalAccessError ee = new IllegalAccessError("Failed to access static method " + methodDescription( 278 declaringClass, name, type)); 279 ee.initCause(e); 280 throw ee; 281 } catch(final NoSuchMethodException e) { 282 final NoSuchMethodError ee = new NoSuchMethodError("Failed to find static method " + methodDescription( 283 declaringClass, name, type)); 284 ee.initCause(e); 285 throw ee; 286 } 287 } 288 289 /** 290 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findVirtual(Class, String, MethodType)} 291 * on the underlying lookup. Converts any encountered 292 * {@link IllegalAccessException} into an {@link IllegalAccessError} and 293 * {@link NoSuchMethodException} into a {@link NoSuchMethodError}. 294 * 295 * @param declaringClass class declaring the method 296 * @param name the name of the method 297 * @param type the type of the method 298 * @return a method handle for the method 299 * @throws IllegalAccessError if the method is inaccessible. 300 * @throws NoSuchMethodError if the method does not exist. 301 */ findVirtual(final Class<?> declaringClass, final String name, final MethodType type)302 public MethodHandle findVirtual(final Class<?> declaringClass, final String name, final MethodType type) { 303 try { 304 return lookup.findVirtual(declaringClass, name, type); 305 } catch(final IllegalAccessException e) { 306 final IllegalAccessError ee = new IllegalAccessError("Failed to access virtual method " + methodDescription( 307 declaringClass, name, type)); 308 ee.initCause(e); 309 throw ee; 310 } catch(final NoSuchMethodException e) { 311 final NoSuchMethodError ee = new NoSuchMethodError("Failed to find virtual method " + methodDescription( 312 declaringClass, name, type)); 313 ee.initCause(e); 314 throw ee; 315 } 316 } 317 318 /** 319 * Given a lookup, finds using {@link #findSpecial(Class, String, MethodType)} 320 * a method on that lookup's class. Useful in classes' code for convenient 321 * linking to their own privates. 322 * @param lookup the lookup for the class 323 * @param name the name of the method 324 * @param rtype the return type of the method 325 * @param ptypes the parameter types of the method 326 * @return the method handle for the method 327 */ findOwnSpecial(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes)328 public static MethodHandle findOwnSpecial(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes) { 329 return new Lookup(lookup).findOwnSpecial(name, rtype, ptypes); 330 } 331 332 333 /** 334 * Finds using {@link #findSpecial(Class, String, MethodType)} a method on 335 * that lookup's class. Useful in classes' code for convenient linking to 336 * their own privates. It's also more convenient than {@code findSpecial} 337 * in that you can just list the parameter types, and don't have to specify 338 * lookup class. 339 * @param name the name of the method 340 * @param rtype the return type of the method 341 * @param ptypes the parameter types of the method 342 * @return the method handle for the method 343 */ findOwnSpecial(final String name, final Class<?> rtype, final Class<?>... ptypes)344 public MethodHandle findOwnSpecial(final String name, final Class<?> rtype, final Class<?>... ptypes) { 345 return findSpecial(lookup.lookupClass(), name, MethodType.methodType(rtype, ptypes)); 346 } 347 348 /** 349 * Given a lookup, finds using {@link #findStatic(Class, String, MethodType)} 350 * a method on that lookup's class. Useful in classes' code for convenient 351 * linking to their own privates. It's easier to use than {@code findStatic} 352 * in that you can just list the parameter types, and don't have to specify 353 * lookup class. 354 * @param lookup the lookup for the class 355 * @param name the name of the method 356 * @param rtype the return type of the method 357 * @param ptypes the parameter types of the method 358 * @return the method handle for the method 359 */ findOwnStatic(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes)360 public static MethodHandle findOwnStatic(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes) { 361 return new Lookup(lookup).findOwnStatic(name, rtype, ptypes); 362 } 363 364 /** 365 * Finds using {@link #findStatic(Class, String, MethodType)} a method on 366 * that lookup's class. Useful in classes' code for convenient linking to 367 * their own privates. It's easier to use than {@code findStatic} 368 * in that you can just list the parameter types, and don't have to specify 369 * lookup class. 370 * @param name the name of the method 371 * @param rtype the return type of the method 372 * @param ptypes the parameter types of the method 373 * @return the method handle for the method 374 */ findOwnStatic(final String name, final Class<?> rtype, final Class<?>... ptypes)375 public MethodHandle findOwnStatic(final String name, final Class<?> rtype, final Class<?>... ptypes) { 376 return findStatic(lookup.lookupClass(), name, MethodType.methodType(rtype, ptypes)); 377 } 378 } 379