src/jdk/internal/dynalink/beans/AccessibleMembersLookup.java

Thu, 14 Feb 2013 13:22:26 +0100

author
attila
date
Thu, 14 Feb 2013 13:22:26 +0100
changeset 90
5a820fb11814
child 811
58214b2432e7
permissions
-rw-r--r--

8008085: Integrate Dynalink source code into Nashorn codebase
Reviewed-by: jlaskey, lagergren, sundar

attila@90 1 /*
attila@90 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
attila@90 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
attila@90 4 *
attila@90 5 * This code is free software; you can redistribute it and/or modify it
attila@90 6 * under the terms of the GNU General Public License version 2 only, as
attila@90 7 * published by the Free Software Foundation. Oracle designates this
attila@90 8 * particular file as subject to the "Classpath" exception as provided
attila@90 9 * by Oracle in the LICENSE file that accompanied this code.
attila@90 10 *
attila@90 11 * This code is distributed in the hope that it will be useful, but WITHOUT
attila@90 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
attila@90 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
attila@90 14 * version 2 for more details (a copy is included in the LICENSE file that
attila@90 15 * accompanied this code).
attila@90 16 *
attila@90 17 * You should have received a copy of the GNU General Public License version
attila@90 18 * 2 along with this work; if not, write to the Free Software Foundation,
attila@90 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
attila@90 20 *
attila@90 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
attila@90 22 * or visit www.oracle.com if you need additional information or have any
attila@90 23 * questions.
attila@90 24 */
attila@90 25
attila@90 26 /*
attila@90 27 * This file is available under and governed by the GNU General Public
attila@90 28 * License version 2 only, as published by the Free Software Foundation.
attila@90 29 * However, the following notice accompanied the original version of this
attila@90 30 * file, and Oracle licenses the original version of this file under the BSD
attila@90 31 * license:
attila@90 32 */
attila@90 33 /*
attila@90 34 Copyright 2009-2013 Attila Szegedi
attila@90 35
attila@90 36 Licensed under both the Apache License, Version 2.0 (the "Apache License")
attila@90 37 and the BSD License (the "BSD License"), with licensee being free to
attila@90 38 choose either of the two at their discretion.
attila@90 39
attila@90 40 You may not use this file except in compliance with either the Apache
attila@90 41 License or the BSD License.
attila@90 42
attila@90 43 If you choose to use this file in compliance with the Apache License, the
attila@90 44 following notice applies to you:
attila@90 45
attila@90 46 You may obtain a copy of the Apache License at
attila@90 47
attila@90 48 http://www.apache.org/licenses/LICENSE-2.0
attila@90 49
attila@90 50 Unless required by applicable law or agreed to in writing, software
attila@90 51 distributed under the License is distributed on an "AS IS" BASIS,
attila@90 52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
attila@90 53 implied. See the License for the specific language governing
attila@90 54 permissions and limitations under the License.
attila@90 55
attila@90 56 If you choose to use this file in compliance with the BSD License, the
attila@90 57 following notice applies to you:
attila@90 58
attila@90 59 Redistribution and use in source and binary forms, with or without
attila@90 60 modification, are permitted provided that the following conditions are
attila@90 61 met:
attila@90 62 * Redistributions of source code must retain the above copyright
attila@90 63 notice, this list of conditions and the following disclaimer.
attila@90 64 * Redistributions in binary form must reproduce the above copyright
attila@90 65 notice, this list of conditions and the following disclaimer in the
attila@90 66 documentation and/or other materials provided with the distribution.
attila@90 67 * Neither the name of the copyright holder nor the names of
attila@90 68 contributors may be used to endorse or promote products derived from
attila@90 69 this software without specific prior written permission.
attila@90 70
attila@90 71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
attila@90 72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
attila@90 73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
attila@90 74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
attila@90 75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
attila@90 76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
attila@90 77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
attila@90 78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
attila@90 79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
attila@90 80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
attila@90 81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
attila@90 82 */
attila@90 83
attila@90 84 package jdk.internal.dynalink.beans;
attila@90 85
attila@90 86 import java.lang.reflect.Method;
attila@90 87 import java.lang.reflect.Modifier;
attila@90 88 import java.util.Arrays;
attila@90 89 import java.util.Collection;
attila@90 90 import java.util.HashMap;
attila@90 91 import java.util.LinkedHashSet;
attila@90 92 import java.util.Map;
attila@90 93 import java.util.Set;
attila@90 94
attila@90 95 /**
attila@90 96 * Utility class for discovering accessible methods and inner classes. Normally, a public member declared on a class is
attila@90 97 * accessible (that is, it can be invoked from anywhere). However, this is not the case if the class itself is not
attila@90 98 * public, or belongs to a restricted-access package. In that case, it is required to lookup a member in a publicly
attila@90 99 * accessible superclass or implemented interface of the class, and use it instead of the member discovered on the
attila@90 100 * class.
attila@90 101 *
attila@90 102 * @author Attila Szegedi
attila@90 103 */
attila@90 104 class AccessibleMembersLookup {
attila@90 105 private final Map<MethodSignature, Method> methods;
attila@90 106 private final Set<Class<?>> innerClasses;
attila@90 107 private boolean instance;
attila@90 108
attila@90 109 /**
attila@90 110 * Creates a mapping for all accessible methods and inner classes on a class.
attila@90 111 *
attila@90 112 * @param clazz the inspected class
attila@90 113 * @param instance true to inspect instance methods, false to inspect static methods.
attila@90 114 */
attila@90 115 AccessibleMembersLookup(final Class<?> clazz, boolean instance) {
attila@90 116 this.methods = new HashMap<>();
attila@90 117 this.innerClasses = new LinkedHashSet<>();
attila@90 118 this.instance = instance;
attila@90 119 lookupAccessibleMembers(clazz);
attila@90 120 }
attila@90 121
attila@90 122 /**
attila@90 123 * Returns an accessible method equivalent of a method.
attila@90 124 *
attila@90 125 * @param m the method whose accessible equivalent is requested.
attila@90 126 * @return the accessible equivalent for the method (can be the same as the passed in method), or null if there is
attila@90 127 * no accessible method equivalent.
attila@90 128 */
attila@90 129 Method getAccessibleMethod(final Method m) {
attila@90 130 return m == null ? null : methods.get(new MethodSignature(m));
attila@90 131 }
attila@90 132
attila@90 133 Collection<Method> getMethods() {
attila@90 134 return methods.values();
attila@90 135 }
attila@90 136
attila@90 137 Class<?>[] getInnerClasses() {
attila@90 138 return innerClasses.toArray(new Class<?>[innerClasses.size()]);
attila@90 139 }
attila@90 140
attila@90 141 /**
attila@90 142 * A helper class that represents a method signature - name and argument types.
attila@90 143 *
attila@90 144 * @author Attila Szegedi
attila@90 145 */
attila@90 146 static final class MethodSignature {
attila@90 147 private final String name;
attila@90 148 private final Class<?>[] args;
attila@90 149
attila@90 150 /**
attila@90 151 * Creates a new method signature from arbitrary data.
attila@90 152 *
attila@90 153 * @param name the name of the method this signature represents.
attila@90 154 * @param args the argument types of the method.
attila@90 155 */
attila@90 156 MethodSignature(String name, Class<?>[] args) {
attila@90 157 this.name = name;
attila@90 158 this.args = args;
attila@90 159 }
attila@90 160
attila@90 161 /**
attila@90 162 * Creates a signature for the given method.
attila@90 163 *
attila@90 164 * @param method the method for which a signature is created.
attila@90 165 */
attila@90 166 MethodSignature(final Method method) {
attila@90 167 this(method.getName(), method.getParameterTypes());
attila@90 168 }
attila@90 169
attila@90 170 /**
attila@90 171 * Compares this object to another object
attila@90 172 *
attila@90 173 * @param o the other object
attila@90 174 * @return true if the other object is also a method signature with the same name, same number of arguments, and
attila@90 175 * same types of arguments.
attila@90 176 */
attila@90 177 @Override
attila@90 178 public boolean equals(final Object o) {
attila@90 179 if(o instanceof MethodSignature) {
attila@90 180 final MethodSignature ms = (MethodSignature)o;
attila@90 181 return ms.name.equals(name) && Arrays.equals(args, ms.args);
attila@90 182 }
attila@90 183 return false;
attila@90 184 }
attila@90 185
attila@90 186 /**
attila@90 187 * Returns a hash code, consistent with the overridden {@link #equals(Object)}.
attila@90 188 */
attila@90 189 @Override
attila@90 190 public int hashCode() {
attila@90 191 return name.hashCode() ^ Arrays.hashCode(args);
attila@90 192 }
attila@90 193
attila@90 194 @Override
attila@90 195 public String toString() {
attila@90 196 final StringBuilder b = new StringBuilder();
attila@90 197 b.append("[MethodSignature ").append(name).append('(');
attila@90 198 if(args.length > 0) {
attila@90 199 b.append(args[0].getCanonicalName());
attila@90 200 for(int i = 1; i < args.length; ++i) {
attila@90 201 b.append(", ").append(args[i].getCanonicalName());
attila@90 202 }
attila@90 203 }
attila@90 204 return b.append(")]").toString();
attila@90 205 }
attila@90 206 }
attila@90 207
attila@90 208 private void lookupAccessibleMembers(final Class<?> clazz) {
attila@90 209 boolean searchSuperTypes;
attila@90 210
attila@90 211 if(!CheckRestrictedPackage.isRestrictedClass(clazz)) {
attila@90 212 searchSuperTypes = false;
attila@90 213 for(Method method: clazz.getMethods()) {
attila@90 214 if(instance != Modifier.isStatic(method.getModifiers())) {
attila@90 215 final MethodSignature sig = new MethodSignature(method);
attila@90 216 if(!methods.containsKey(sig)) {
attila@90 217 final Class<?> declaringClass = method.getDeclaringClass();
attila@90 218 if(declaringClass != clazz && CheckRestrictedPackage.isRestrictedClass(declaringClass)) {
attila@90 219 //Sometimes, the declaring class of a method (Method.getDeclaringClass())
attila@90 220 //retrieved through Class.getMethods() for a public class will be a
attila@90 221 //non-public superclass. For such a method, we need to find a method with
attila@90 222 //the same name and signature in a public superclass or implemented
attila@90 223 //interface.
attila@90 224 //This typically doesn't happen with classes emitted by a reasonably modern
attila@90 225 //javac, as it'll create synthetic delegator methods in all public
attila@90 226 //immediate subclasses of the non-public class. We have, however, observed
attila@90 227 //this in the wild with class files compiled with older javac that doesn't
attila@90 228 //generate the said synthetic delegators.
attila@90 229 searchSuperTypes = true;
attila@90 230 } else {
attila@90 231 methods.put(sig, method);
attila@90 232 }
attila@90 233 }
attila@90 234 }
attila@90 235 }
attila@90 236 for(Class<?> innerClass: clazz.getClasses()) {
attila@90 237 // Add both static and non-static classes, regardless of instance flag. StaticClassLinker will just
attila@90 238 // expose non-static classes with explicit constructor outer class argument.
attila@90 239 // NOTE: getting inner class objects through getClasses() does not resolve them, so if those classes
attila@90 240 // were not yet loaded, they'll only get loaded in a non-resolved state; no static initializers for
attila@90 241 // them will trigger just by doing this.
attila@90 242 innerClasses.add(innerClass);
attila@90 243 }
attila@90 244 } else {
attila@90 245 searchSuperTypes = true;
attila@90 246 }
attila@90 247
attila@90 248 if(searchSuperTypes) {
attila@90 249 // If we reach here, the class is either not public, or it is in a restricted package. Alternatively, it is
attila@90 250 // public, but some of its methods claim that their declaring class is non-public. We'll try superclasses
attila@90 251 // and implemented interfaces then looking for public ones.
attila@90 252 final Class<?>[] interfaces = clazz.getInterfaces();
attila@90 253 for(int i = 0; i < interfaces.length; i++) {
attila@90 254 lookupAccessibleMembers(interfaces[i]);
attila@90 255 }
attila@90 256 final Class<?> superclass = clazz.getSuperclass();
attila@90 257 if(superclass != null) {
attila@90 258 lookupAccessibleMembers(superclass);
attila@90 259 }
attila@90 260 }
attila@90 261 }
attila@90 262 }

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