1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/jdk/internal/dynalink/support/TypeUtilities.java Wed Apr 27 01:36:41 2016 +0800
1.3 @@ -0,0 +1,442 @@
1.4 +/*
1.5 + * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +/*
1.30 + * This file is available under and governed by the GNU General Public
1.31 + * License version 2 only, as published by the Free Software Foundation.
1.32 + * However, the following notice accompanied the original version of this
1.33 + * file, and Oracle licenses the original version of this file under the BSD
1.34 + * license:
1.35 + */
1.36 +/*
1.37 + Copyright 2009-2013 Attila Szegedi
1.38 +
1.39 + Licensed under both the Apache License, Version 2.0 (the "Apache License")
1.40 + and the BSD License (the "BSD License"), with licensee being free to
1.41 + choose either of the two at their discretion.
1.42 +
1.43 + You may not use this file except in compliance with either the Apache
1.44 + License or the BSD License.
1.45 +
1.46 + If you choose to use this file in compliance with the Apache License, the
1.47 + following notice applies to you:
1.48 +
1.49 + You may obtain a copy of the Apache License at
1.50 +
1.51 + http://www.apache.org/licenses/LICENSE-2.0
1.52 +
1.53 + Unless required by applicable law or agreed to in writing, software
1.54 + distributed under the License is distributed on an "AS IS" BASIS,
1.55 + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
1.56 + implied. See the License for the specific language governing
1.57 + permissions and limitations under the License.
1.58 +
1.59 + If you choose to use this file in compliance with the BSD License, the
1.60 + following notice applies to you:
1.61 +
1.62 + Redistribution and use in source and binary forms, with or without
1.63 + modification, are permitted provided that the following conditions are
1.64 + met:
1.65 + * Redistributions of source code must retain the above copyright
1.66 + notice, this list of conditions and the following disclaimer.
1.67 + * Redistributions in binary form must reproduce the above copyright
1.68 + notice, this list of conditions and the following disclaimer in the
1.69 + documentation and/or other materials provided with the distribution.
1.70 + * Neither the name of the copyright holder nor the names of
1.71 + contributors may be used to endorse or promote products derived from
1.72 + this software without specific prior written permission.
1.73 +
1.74 + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
1.75 + IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
1.76 + TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
1.77 + PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
1.78 + BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.79 + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.80 + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
1.81 + BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
1.82 + WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
1.83 + OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
1.84 + ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.85 +*/
1.86 +
1.87 +package jdk.internal.dynalink.support;
1.88 +
1.89 +import java.util.ArrayList;
1.90 +import java.util.Collection;
1.91 +import java.util.Collections;
1.92 +import java.util.HashMap;
1.93 +import java.util.HashSet;
1.94 +import java.util.IdentityHashMap;
1.95 +import java.util.Iterator;
1.96 +import java.util.List;
1.97 +import java.util.Map;
1.98 +import java.util.Set;
1.99 +
1.100 +/**
1.101 + * Various static utility methods for testing type relationships.
1.102 + *
1.103 + * @author Attila Szegedi
1.104 + */
1.105 +public class TypeUtilities {
1.106 + static final Class<Object> OBJECT_CLASS = Object.class;
1.107 +
1.108 + private TypeUtilities() {
1.109 + }
1.110 +
1.111 + /**
1.112 + * Given two types represented by c1 and c2, returns a type that is their most specific common superclass or
1.113 + * superinterface.
1.114 + *
1.115 + * @param c1 one type
1.116 + * @param c2 another type
1.117 + * @return their most common superclass or superinterface. If they have several unrelated superinterfaces as their
1.118 + * most specific common type, or the types themselves are completely unrelated interfaces, {@link java.lang.Object}
1.119 + * is returned.
1.120 + */
1.121 + public static Class<?> getMostSpecificCommonType(Class<?> c1, Class<?> c2) {
1.122 + if(c1 == c2) {
1.123 + return c1;
1.124 + }
1.125 + Class<?> c3 = c2;
1.126 + if(c3.isPrimitive()) {
1.127 + if(c3 == Byte.TYPE)
1.128 + c3 = Byte.class;
1.129 + else if(c3 == Short.TYPE)
1.130 + c3 = Short.class;
1.131 + else if(c3 == Character.TYPE)
1.132 + c3 = Character.class;
1.133 + else if(c3 == Integer.TYPE)
1.134 + c3 = Integer.class;
1.135 + else if(c3 == Float.TYPE)
1.136 + c3 = Float.class;
1.137 + else if(c3 == Long.TYPE)
1.138 + c3 = Long.class;
1.139 + else if(c3 == Double.TYPE)
1.140 + c3 = Double.class;
1.141 + }
1.142 + Set<Class<?>> a1 = getAssignables(c1, c3);
1.143 + Set<Class<?>> a2 = getAssignables(c3, c1);
1.144 + a1.retainAll(a2);
1.145 + if(a1.isEmpty()) {
1.146 + // Can happen when at least one of the arguments is an interface,
1.147 + // as they don't have Object at the root of their hierarchy.
1.148 + return Object.class;
1.149 + }
1.150 + // Gather maximally specific elements. Yes, there can be more than one
1.151 + // thank to interfaces. I.e., if you call this method for String.class
1.152 + // and Number.class, you'll have Comparable, Serializable, and Object
1.153 + // as maximal elements.
1.154 + List<Class<?>> max = new ArrayList<>();
1.155 + outer: for(Class<?> clazz: a1) {
1.156 + for(Iterator<Class<?>> maxiter = max.iterator(); maxiter.hasNext();) {
1.157 + Class<?> maxClazz = maxiter.next();
1.158 + if(isSubtype(maxClazz, clazz)) {
1.159 + // It can't be maximal, if there's already a more specific
1.160 + // maximal than it.
1.161 + continue outer;
1.162 + }
1.163 + if(isSubtype(clazz, maxClazz)) {
1.164 + // If it's more specific than a currently maximal element,
1.165 + // that currently maximal is no longer a maximal.
1.166 + maxiter.remove();
1.167 + }
1.168 + }
1.169 + // If we get here, no current maximal is more specific than the
1.170 + // current class, so it is considered maximal as well
1.171 + max.add(clazz);
1.172 + }
1.173 + if(max.size() > 1) {
1.174 + return OBJECT_CLASS;
1.175 + }
1.176 + return max.get(0);
1.177 + }
1.178 +
1.179 + private static Set<Class<?>> getAssignables(Class<?> c1, Class<?> c2) {
1.180 + Set<Class<?>> s = new HashSet<>();
1.181 + collectAssignables(c1, c2, s);
1.182 + return s;
1.183 + }
1.184 +
1.185 + private static void collectAssignables(Class<?> c1, Class<?> c2, Set<Class<?>> s) {
1.186 + if(c1.isAssignableFrom(c2)) {
1.187 + s.add(c1);
1.188 + }
1.189 + Class<?> sc = c1.getSuperclass();
1.190 + if(sc != null) {
1.191 + collectAssignables(sc, c2, s);
1.192 + }
1.193 + Class<?>[] itf = c1.getInterfaces();
1.194 + for(int i = 0; i < itf.length; ++i) {
1.195 + collectAssignables(itf[i], c2, s);
1.196 + }
1.197 + }
1.198 +
1.199 + private static final Map<Class<?>, Class<?>> WRAPPER_TYPES = createWrapperTypes();
1.200 + private static final Map<Class<?>, Class<?>> PRIMITIVE_TYPES = invertMap(WRAPPER_TYPES);
1.201 + private static final Map<String, Class<?>> PRIMITIVE_TYPES_BY_NAME = createClassNameMapping(WRAPPER_TYPES.keySet());
1.202 +
1.203 + private static Map<Class<?>, Class<?>> createWrapperTypes() {
1.204 + final Map<Class<?>, Class<?>> wrapperTypes = new IdentityHashMap<>(8);
1.205 + wrapperTypes.put(Boolean.TYPE, Boolean.class);
1.206 + wrapperTypes.put(Byte.TYPE, Byte.class);
1.207 + wrapperTypes.put(Character.TYPE, Character.class);
1.208 + wrapperTypes.put(Short.TYPE, Short.class);
1.209 + wrapperTypes.put(Integer.TYPE, Integer.class);
1.210 + wrapperTypes.put(Long.TYPE, Long.class);
1.211 + wrapperTypes.put(Float.TYPE, Float.class);
1.212 + wrapperTypes.put(Double.TYPE, Double.class);
1.213 + return Collections.unmodifiableMap(wrapperTypes);
1.214 + }
1.215 +
1.216 + private static Map<String, Class<?>> createClassNameMapping(Collection<Class<?>> classes) {
1.217 + final Map<String, Class<?>> map = new HashMap<>();
1.218 + for(Class<?> clazz: classes) {
1.219 + map.put(clazz.getName(), clazz);
1.220 + }
1.221 + return map;
1.222 + }
1.223 +
1.224 + private static <K, V> Map<V, K> invertMap(Map<K, V> map) {
1.225 + final Map<V, K> inverted = new IdentityHashMap<>(map.size());
1.226 + for(Map.Entry<K, V> entry: map.entrySet()) {
1.227 + inverted.put(entry.getValue(), entry.getKey());
1.228 + }
1.229 + return Collections.unmodifiableMap(inverted);
1.230 + }
1.231 +
1.232 + /**
1.233 + * Determines whether one type can be converted to another type using a method invocation conversion, as per JLS 5.3
1.234 + * "Method Invocation Conversion". This is basically all conversions allowed by subtyping (see
1.235 + * {@link #isSubtype(Class, Class)}) as well as boxing conversion (JLS 5.1.7) optionally followed by widening
1.236 + * reference conversion and unboxing conversion (JLS 5.1.8) optionally followed by widening primitive conversion.
1.237 + *
1.238 + * @param callSiteType the parameter type at the call site
1.239 + * @param methodType the parameter type in the method declaration
1.240 + * @return true if callSiteType is method invocation convertible to the methodType.
1.241 + */
1.242 + public static boolean isMethodInvocationConvertible(Class<?> callSiteType, Class<?> methodType) {
1.243 + if(methodType.isAssignableFrom(callSiteType)) {
1.244 + return true;
1.245 + }
1.246 + if(callSiteType.isPrimitive()) {
1.247 + if(methodType.isPrimitive()) {
1.248 + return isProperPrimitiveSubtype(callSiteType, methodType);
1.249 + }
1.250 + // Boxing + widening reference conversion
1.251 + return methodType.isAssignableFrom(WRAPPER_TYPES.get(callSiteType));
1.252 + }
1.253 + if(methodType.isPrimitive()) {
1.254 + final Class<?> unboxedCallSiteType = PRIMITIVE_TYPES.get(callSiteType);
1.255 + return unboxedCallSiteType != null
1.256 + && (unboxedCallSiteType == methodType || isProperPrimitiveSubtype(unboxedCallSiteType, methodType));
1.257 + }
1.258 + return false;
1.259 + }
1.260 +
1.261 + /**
1.262 + * Determines whether one type can be potentially converted to another type at runtime. Allows a conversion between
1.263 + * any subtype and supertype in either direction, and also allows a conversion between any two primitive types, as
1.264 + * well as between any primitive type and any reference type that can hold a boxed primitive.
1.265 + *
1.266 + * @param callSiteType the parameter type at the call site
1.267 + * @param methodType the parameter type in the method declaration
1.268 + * @return true if callSiteType is potentially convertible to the methodType.
1.269 + */
1.270 + public static boolean isPotentiallyConvertible(Class<?> callSiteType, Class<?> methodType) {
1.271 + // Widening or narrowing reference conversion
1.272 + if(methodType.isAssignableFrom(callSiteType) || callSiteType.isAssignableFrom(methodType)) {
1.273 + return true;
1.274 + }
1.275 + if(callSiteType.isPrimitive()) {
1.276 + // Allow any conversion among primitives, as well as from any
1.277 + // primitive to any type that can receive a boxed primitive.
1.278 + // TODO: narrow this a bit, i.e. allow, say, boolean to Character?
1.279 + // MethodHandles.convertArguments() allows it, so we might need to
1.280 + // too.
1.281 + return methodType.isPrimitive() || isAssignableFromBoxedPrimitive(methodType);
1.282 + }
1.283 + if(methodType.isPrimitive()) {
1.284 + // Allow conversion from any reference type that can contain a
1.285 + // boxed primitive to any primitive.
1.286 + // TODO: narrow this a bit too?
1.287 + return isAssignableFromBoxedPrimitive(callSiteType);
1.288 + }
1.289 + return false;
1.290 + }
1.291 +
1.292 + /**
1.293 + * Determines whether one type is a subtype of another type, as per JLS 4.10 "Subtyping". Note: this is not strict
1.294 + * or proper subtype, therefore true is also returned for identical types; to be completely precise, it allows
1.295 + * identity conversion (JLS 5.1.1), widening primitive conversion (JLS 5.1.2) and widening reference conversion (JLS
1.296 + * 5.1.5).
1.297 + *
1.298 + * @param subType the supposed subtype
1.299 + * @param superType the supposed supertype of the subtype
1.300 + * @return true if subType can be converted by identity conversion, widening primitive conversion, or widening
1.301 + * reference conversion to superType.
1.302 + */
1.303 + public static boolean isSubtype(Class<?> subType, Class<?> superType) {
1.304 + // Covers both JLS 4.10.2 "Subtyping among Class and Interface Types"
1.305 + // and JLS 4.10.3 "Subtyping among Array Types", as well as primitive
1.306 + // type identity.
1.307 + if(superType.isAssignableFrom(subType)) {
1.308 + return true;
1.309 + }
1.310 + // JLS 4.10.1 "Subtyping among Primitive Types". Note we don't test for
1.311 + // identity, as identical types were taken care of in the
1.312 + // isAssignableFrom test. As per 4.10.1, the supertype relation is as
1.313 + // follows:
1.314 + // double > float
1.315 + // float > long
1.316 + // long > int
1.317 + // int > short
1.318 + // int > char
1.319 + // short > byte
1.320 + if(superType.isPrimitive() && subType.isPrimitive()) {
1.321 + return isProperPrimitiveSubtype(subType, superType);
1.322 + }
1.323 + return false;
1.324 + }
1.325 +
1.326 + /**
1.327 + * Returns true if a supposed primitive subtype is a proper subtype ( meaning, subtype and not identical) of the
1.328 + * supposed primitive supertype
1.329 + *
1.330 + * @param subType the supposed subtype
1.331 + * @param superType the supposed supertype
1.332 + * @return true if subType is a proper (not identical to) primitive subtype of the superType
1.333 + */
1.334 + private static boolean isProperPrimitiveSubtype(Class<?> subType, Class<?> superType) {
1.335 + if(superType == boolean.class || subType == boolean.class) {
1.336 + return false;
1.337 + }
1.338 + if(subType == byte.class) {
1.339 + return superType != char.class;
1.340 + }
1.341 + if(subType == char.class) {
1.342 + return superType != short.class && superType != byte.class;
1.343 + }
1.344 + if(subType == short.class) {
1.345 + return superType != char.class && superType != byte.class;
1.346 + }
1.347 + if(subType == int.class) {
1.348 + return superType == long.class || superType == float.class || superType == double.class;
1.349 + }
1.350 + if(subType == long.class) {
1.351 + return superType == float.class || superType == double.class;
1.352 + }
1.353 + if(subType == float.class) {
1.354 + return superType == double.class;
1.355 + }
1.356 + return false;
1.357 + }
1.358 +
1.359 + private static final Map<Class<?>, Class<?>> WRAPPER_TO_PRIMITIVE_TYPES = createWrapperToPrimitiveTypes();
1.360 +
1.361 + private static Map<Class<?>, Class<?>> createWrapperToPrimitiveTypes() {
1.362 + final Map<Class<?>, Class<?>> classes = new IdentityHashMap<>();
1.363 + classes.put(Void.class, Void.TYPE);
1.364 + classes.put(Boolean.class, Boolean.TYPE);
1.365 + classes.put(Byte.class, Byte.TYPE);
1.366 + classes.put(Character.class, Character.TYPE);
1.367 + classes.put(Short.class, Short.TYPE);
1.368 + classes.put(Integer.class, Integer.TYPE);
1.369 + classes.put(Long.class, Long.TYPE);
1.370 + classes.put(Float.class, Float.TYPE);
1.371 + classes.put(Double.class, Double.TYPE);
1.372 + return classes;
1.373 + }
1.374 +
1.375 + private static final Set<Class<?>> PRIMITIVE_WRAPPER_TYPES = createPrimitiveWrapperTypes();
1.376 +
1.377 + private static Set<Class<?>> createPrimitiveWrapperTypes() {
1.378 + final Map<Class<?>, Class<?>> classes = new IdentityHashMap<>();
1.379 + addClassHierarchy(classes, Boolean.class);
1.380 + addClassHierarchy(classes, Byte.class);
1.381 + addClassHierarchy(classes, Character.class);
1.382 + addClassHierarchy(classes, Short.class);
1.383 + addClassHierarchy(classes, Integer.class);
1.384 + addClassHierarchy(classes, Long.class);
1.385 + addClassHierarchy(classes, Float.class);
1.386 + addClassHierarchy(classes, Double.class);
1.387 + return classes.keySet();
1.388 + }
1.389 +
1.390 + private static void addClassHierarchy(Map<Class<?>, Class<?>> map, Class<?> clazz) {
1.391 + if(clazz == null) {
1.392 + return;
1.393 + }
1.394 + map.put(clazz, clazz);
1.395 + addClassHierarchy(map, clazz.getSuperclass());
1.396 + for(Class<?> itf: clazz.getInterfaces()) {
1.397 + addClassHierarchy(map, itf);
1.398 + }
1.399 + }
1.400 +
1.401 + /**
1.402 + * Returns true if the class can be assigned from any boxed primitive.
1.403 + *
1.404 + * @param clazz the class
1.405 + * @return true if the class can be assigned from any boxed primitive. Basically, it is true if the class is any
1.406 + * primitive wrapper class, or a superclass or superinterface of any primitive wrapper class.
1.407 + */
1.408 + private static boolean isAssignableFromBoxedPrimitive(Class<?> clazz) {
1.409 + return PRIMITIVE_WRAPPER_TYPES.contains(clazz);
1.410 + }
1.411 +
1.412 + /**
1.413 + * Given a name of a primitive type (except "void"), returns the class representing it. I.e. when invoked with
1.414 + * "int", returns {@link Integer#TYPE}.
1.415 + * @param name the name of the primitive type
1.416 + * @return the class representing the primitive type, or null if the name does not correspond to a primitive type
1.417 + * or is "void".
1.418 + */
1.419 + public static Class<?> getPrimitiveTypeByName(String name) {
1.420 + return PRIMITIVE_TYPES_BY_NAME.get(name);
1.421 + }
1.422 +
1.423 + /**
1.424 + * When passed a class representing a wrapper for a primitive type, returns the class representing the corresponding
1.425 + * primitive type. I.e. calling it with {@code Integer.class} will return {@code Integer.TYPE}. If passed a class
1.426 + * that is not a wrapper for primitive type, returns null.
1.427 + * @param wrapperType the class object representing a wrapper for a primitive type
1.428 + * @return the class object representing the primitive type, or null if the passed class is not a primitive wrapper.
1.429 + */
1.430 + public static Class<?> getPrimitiveType(Class<?> wrapperType) {
1.431 + return WRAPPER_TO_PRIMITIVE_TYPES.get(wrapperType);
1.432 + }
1.433 +
1.434 +
1.435 + /**
1.436 + * When passed a class representing a primitive type, returns the class representing the corresponding
1.437 + * wrapper type. I.e. calling it with {@code int.class} will return {@code Integer.class}. If passed a class
1.438 + * that is not a primitive type, returns null.
1.439 + * @param primitiveType the class object representing a primitive type
1.440 + * @return the class object representing the wrapper type, or null if the passed class is not a primitive.
1.441 + */
1.442 + public static Class<?> getWrapperType(Class<?> primitiveType) {
1.443 + return WRAPPER_TYPES.get(primitiveType);
1.444 + }
1.445 +}
