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.Executable; 68 import java.lang.reflect.Field; 69 import java.lang.reflect.Method; 70 71 /** 72 * A wrapper around {@link java.lang.invoke.MethodHandles.Lookup} that masks 73 * checked exceptions. It is useful in those cases when you're looking up 74 * methods within your own codebase (therefore it is an error if they are not 75 * present). 76 */ 77 public final class Lookup { 78 private final MethodHandles.Lookup lookup; 79 80 /** 81 * Creates a new instance, bound to an instance of 82 * {@link java.lang.invoke.MethodHandles.Lookup}. 83 * 84 * @param lookup the {@link java.lang.invoke.MethodHandles.Lookup} it delegates to. 85 */ Lookup(final MethodHandles.Lookup lookup)86 public Lookup(final MethodHandles.Lookup lookup) { 87 this.lookup = lookup; 88 } 89 90 /** 91 * A canonical Lookup object that wraps {@link MethodHandles#publicLookup()}. 92 */ 93 public static final Lookup PUBLIC = new Lookup(MethodHandles.publicLookup()); 94 95 /** 96 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflect(Method)}, 97 * converting any encountered {@link IllegalAccessException} into an 98 * {@link IllegalAccessError}. 99 * 100 * @param m the method to unreflect 101 * @return the unreflected method handle. 102 * @throws IllegalAccessError if the method is inaccessible. 103 */ unreflect(final Method m)104 public MethodHandle unreflect(final Method m) { 105 return unreflect(lookup, m); 106 } 107 108 /** 109 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflect(Method)}, 110 * converting any encountered {@link IllegalAccessException} into an 111 * {@link IllegalAccessError}. 112 * 113 * @param lookup the lookup used to unreflect 114 * @param m the method to unreflect 115 * @return the unreflected method handle. 116 * @throws IllegalAccessError if the method is inaccessible. 117 */ unreflect(final MethodHandles.Lookup lookup, final Method m)118 public static MethodHandle unreflect(final MethodHandles.Lookup lookup, final Method m) { 119 try { 120 return lookup.unreflect(m); 121 } catch(final IllegalAccessException e) { 122 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect method " + m); 123 ee.initCause(e); 124 throw ee; 125 } 126 } 127 128 /** 129 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectGetter(Field)}, 130 * converting any encountered {@link IllegalAccessException} into an {@link IllegalAccessError}. 131 * 132 * @param f the field for which a getter is unreflected 133 * @return the unreflected field getter handle. 134 * @throws IllegalAccessError if the getter is inaccessible. 135 */ unreflectGetter(final Field f)136 public MethodHandle unreflectGetter(final Field f) { 137 try { 138 return lookup.unreflectGetter(f); 139 } catch(final IllegalAccessException e) { 140 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect getter for field " + f); 141 ee.initCause(e); 142 throw ee; 143 } 144 } 145 146 /** 147 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findGetter(Class, String, Class)}, 148 * converting any encountered {@link IllegalAccessException} into an 149 * {@link IllegalAccessError} and {@link NoSuchFieldException} into a 150 * {@link NoSuchFieldError}. 151 * 152 * @param refc the class declaring the field 153 * @param name the name of the field 154 * @param type the type of the field 155 * @return the unreflected field getter handle. 156 * @throws IllegalAccessError if the field is inaccessible. 157 * @throws NoSuchFieldError if the field does not exist. 158 */ findGetter(final Class<?>refc, final String name, final Class<?> type)159 public MethodHandle findGetter(final Class<?>refc, final String name, final Class<?> type) { 160 try { 161 return lookup.findGetter(refc, name, type); 162 } catch(final IllegalAccessException e) { 163 final IllegalAccessError ee = new IllegalAccessError("Failed to access getter for field " + refc.getName() + 164 "." + name + " of type " + type.getName()); 165 ee.initCause(e); 166 throw ee; 167 } catch(final NoSuchFieldException e) { 168 final NoSuchFieldError ee = new NoSuchFieldError("Failed to find getter for field " + refc.getName() + 169 "." + name + " of type " + type.getName()); 170 ee.initCause(e); 171 throw ee; 172 } 173 } 174 175 /** 176 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectSetter(Field)}, 177 * converting any encountered {@link IllegalAccessException} into an 178 * {@link IllegalAccessError}. 179 * 180 * @param f the field for which a setter is unreflected 181 * @return the unreflected field setter handle. 182 * @throws IllegalAccessError if the field is inaccessible. 183 * @throws NoSuchFieldError if the field does not exist. 184 */ unreflectSetter(final Field f)185 public MethodHandle unreflectSetter(final Field f) { 186 try { 187 return lookup.unreflectSetter(f); 188 } catch(final IllegalAccessException e) { 189 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect setter for field " + f); 190 ee.initCause(e); 191 throw ee; 192 } 193 } 194 195 /** 196 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectConstructor(Constructor)}, 197 * converting any encountered {@link IllegalAccessException} into an 198 * {@link IllegalAccessError}. 199 * 200 * @param c the constructor to unreflect 201 * @return the unreflected constructor handle. 202 * @throws IllegalAccessError if the constructor is inaccessible. 203 */ unreflectConstructor(final Constructor<?> c)204 public MethodHandle unreflectConstructor(final Constructor<?> c) { 205 return unreflectConstructor(lookup, c); 206 } 207 208 /** 209 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#unreflectConstructor(Constructor)}, 210 * converting any encountered {@link IllegalAccessException} into an 211 * {@link IllegalAccessError}. 212 * 213 * @param lookup the lookup used to unreflect 214 * @param c the constructor to unreflect 215 * @return the unreflected constructor handle. 216 * @throws IllegalAccessError if the constructor is inaccessible. 217 */ unreflectConstructor(final MethodHandles.Lookup lookup, final Constructor<?> c)218 public static MethodHandle unreflectConstructor(final MethodHandles.Lookup lookup, final Constructor<?> c) { 219 try { 220 return lookup.unreflectConstructor(c); 221 } catch(final IllegalAccessException e) { 222 final IllegalAccessError ee = new IllegalAccessError("Failed to unreflect constructor " + c); 223 ee.initCause(e); 224 throw ee; 225 } 226 } 227 228 /** 229 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findSpecial(Class, String, MethodType, Class)} 230 * on the underlying lookup. Converts any encountered 231 * {@link IllegalAccessException} into an {@link IllegalAccessError} and 232 * {@link NoSuchMethodException} into a {@link NoSuchMethodError}. 233 * 234 * @param declaringClass class declaring the method 235 * @param name the name of the method 236 * @param type the type of the method 237 * @return a method handle for the method 238 * @throws IllegalAccessError if the method is inaccessible. 239 * @throws NoSuchMethodError if the method does not exist. 240 */ findSpecial(final Class<?> declaringClass, final String name, final MethodType type)241 public MethodHandle findSpecial(final Class<?> declaringClass, final String name, final MethodType type) { 242 try { 243 return lookup.findSpecial(declaringClass, name, type, declaringClass); 244 } catch(final IllegalAccessException e) { 245 final IllegalAccessError ee = new IllegalAccessError("Failed to access special method " + methodDescription( 246 declaringClass, name, type)); 247 ee.initCause(e); 248 throw ee; 249 } catch(final NoSuchMethodException e) { 250 final NoSuchMethodError ee = new NoSuchMethodError("Failed to find special method " + methodDescription( 251 declaringClass, name, type)); 252 ee.initCause(e); 253 throw ee; 254 } 255 } 256 methodDescription(final Class<?> declaringClass, final String name, final MethodType type)257 private static String methodDescription(final Class<?> declaringClass, final String name, final MethodType type) { 258 return declaringClass.getName() + "#" + name + type; 259 } 260 261 /** 262 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findStatic(Class, String, MethodType)} 263 * on the underlying lookup. Converts any encountered 264 * {@link IllegalAccessException} into an {@link IllegalAccessError} and 265 * {@link NoSuchMethodException} into a {@link NoSuchMethodError}. 266 * 267 * @param declaringClass class declaring the method 268 * @param name the name of the method 269 * @param type the type of the method 270 * @return a method handle for the method 271 * @throws IllegalAccessError if the method is inaccessible. 272 * @throws NoSuchMethodError if the method does not exist. 273 */ findStatic(final Class<?> declaringClass, final String name, final MethodType type)274 public MethodHandle findStatic(final Class<?> declaringClass, final String name, final MethodType type) { 275 try { 276 return lookup.findStatic(declaringClass, name, type); 277 } catch(final IllegalAccessException e) { 278 final IllegalAccessError ee = new IllegalAccessError("Failed to access static method " + methodDescription( 279 declaringClass, name, type)); 280 ee.initCause(e); 281 throw ee; 282 } catch(final NoSuchMethodException e) { 283 final NoSuchMethodError ee = new NoSuchMethodError("Failed to find static method " + methodDescription( 284 declaringClass, name, type)); 285 ee.initCause(e); 286 throw ee; 287 } 288 } 289 290 /** 291 * Performs a {@link java.lang.invoke.MethodHandles.Lookup#findVirtual(Class, String, MethodType)} 292 * on the underlying lookup. Converts any encountered 293 * {@link IllegalAccessException} into an {@link IllegalAccessError} and 294 * {@link NoSuchMethodException} into a {@link NoSuchMethodError}. 295 * 296 * @param declaringClass class declaring the method 297 * @param name the name of the method 298 * @param type the type of the method 299 * @return a method handle for the method 300 * @throws IllegalAccessError if the method is inaccessible. 301 * @throws NoSuchMethodError if the method does not exist. 302 */ findVirtual(final Class<?> declaringClass, final String name, final MethodType type)303 public MethodHandle findVirtual(final Class<?> declaringClass, final String name, final MethodType type) { 304 try { 305 return lookup.findVirtual(declaringClass, name, type); 306 } catch(final IllegalAccessException e) { 307 final IllegalAccessError ee = new IllegalAccessError("Failed to access virtual method " + methodDescription( 308 declaringClass, name, type)); 309 ee.initCause(e); 310 throw ee; 311 } catch(final NoSuchMethodException e) { 312 final NoSuchMethodError ee = new NoSuchMethodError("Failed to find virtual method " + methodDescription( 313 declaringClass, name, type)); 314 ee.initCause(e); 315 throw ee; 316 } 317 } 318 319 /** 320 * Given a lookup, finds using {@link #findSpecial(Class, String, MethodType)} 321 * a method on that lookup's class. Useful in classes' code for convenient 322 * linking to their own privates. 323 * @param lookup the lookup for the class 324 * @param name the name of the method 325 * @param rtype the return type of the method 326 * @param ptypes the parameter types of the method 327 * @return the method handle for the method 328 */ findOwnSpecial(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes)329 public static MethodHandle findOwnSpecial(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes) { 330 return new Lookup(lookup).findOwnSpecial(name, rtype, ptypes); 331 } 332 333 334 /** 335 * Finds using {@link #findSpecial(Class, String, MethodType)} a method on 336 * that lookup's class. Useful in classes' code for convenient linking to 337 * their own privates. It's also more convenient than {@code findSpecial} 338 * in that you can just list the parameter types, and don't have to specify 339 * lookup class. 340 * @param name the name of the method 341 * @param rtype the return type of the method 342 * @param ptypes the parameter types of the method 343 * @return the method handle for the method 344 */ findOwnSpecial(final String name, final Class<?> rtype, final Class<?>... ptypes)345 public MethodHandle findOwnSpecial(final String name, final Class<?> rtype, final Class<?>... ptypes) { 346 return findSpecial(lookup.lookupClass(), name, MethodType.methodType(rtype, ptypes)); 347 } 348 349 /** 350 * Given a lookup, finds using {@link #findStatic(Class, String, MethodType)} 351 * a method on that lookup's class. Useful in classes' code for convenient 352 * linking to their own privates. It's easier to use than {@code findStatic} 353 * in that you can just list the parameter types, and don't have to specify 354 * lookup class. 355 * @param lookup the lookup for the class 356 * @param name the name of the method 357 * @param rtype the return type of the method 358 * @param ptypes the parameter types of the method 359 * @return the method handle for the method 360 */ findOwnStatic(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes)361 public static MethodHandle findOwnStatic(final MethodHandles.Lookup lookup, final String name, final Class<?> rtype, final Class<?>... ptypes) { 362 return new Lookup(lookup).findOwnStatic(name, rtype, ptypes); 363 } 364 365 /** 366 * Finds using {@link #findStatic(Class, String, MethodType)} a method on 367 * that lookup's class. Useful in classes' code for convenient linking to 368 * their own privates. It's easier to use than {@code findStatic} 369 * in that you can just list the parameter types, and don't have to specify 370 * lookup class. 371 * @param name the name of the method 372 * @param rtype the return type of the method 373 * @param ptypes the parameter types of the method 374 * @return the method handle for the method 375 */ findOwnStatic(final String name, final Class<?> rtype, final Class<?>... ptypes)376 public MethodHandle findOwnStatic(final String name, final Class<?> rtype, final Class<?>... ptypes) { 377 return findStatic(lookup.lookupClass(), name, MethodType.methodType(rtype, ptypes)); 378 } 379 } 380