| /* |
| * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file, and Oracle licenses the original version of this file under the BSD |
| * license: |
| */ |
| /* |
| Copyright 2009-2013 Attila Szegedi |
| |
| Licensed under both the Apache License, Version 2.0 (the "Apache License") |
| and the BSD License (the "BSD License"), with licensee being free to |
| choose either of the two at their discretion. |
| |
| You may not use this file except in compliance with either the Apache |
| License or the BSD License. |
| |
| If you choose to use this file in compliance with the Apache License, the |
| following notice applies to you: |
| |
| You may obtain a copy of the Apache License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| implied. See the License for the specific language governing |
| permissions and limitations under the License. |
| |
| If you choose to use this file in compliance with the BSD License, the |
| following notice applies to you: |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are |
| met: |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| * Neither the name of the copyright holder nor the names of |
| contributors may be used to endorse or promote products derived from |
| this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
| IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A |
| PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER |
| BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
| BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package jdk.internal.dynalink.support; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.IdentityHashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * Various static utility methods for testing type relationships. |
| * |
| * @author Attila Szegedi |
| */ |
| public class TypeUtilities { |
| static final Class<Object> OBJECT_CLASS = Object.class; |
| |
| private TypeUtilities() { |
| } |
| |
| /** |
| * Given two types represented by c1 and c2, returns a type that is their most specific common supertype for |
| * purposes of lossless conversions. |
| * |
| * @param c1 one type |
| * @param c2 another type |
| * @return their most common superclass or superinterface for purposes of lossless conversions. If they have several |
| * unrelated superinterfaces as their most specific common type, or the types themselves are completely |
| * unrelated interfaces, {@link java.lang.Object} is returned. |
| */ |
| public static Class<?> getCommonLosslessConversionType(final Class<?> c1, final Class<?> c2) { |
| if(c1 == c2) { |
| return c1; |
| } else if (c1 == void.class || c2 == void.class) { |
| return Object.class; |
| } else if(isConvertibleWithoutLoss(c2, c1)) { |
| return c1; |
| } else if(isConvertibleWithoutLoss(c1, c2)) { |
| return c2; |
| } else if(c1.isPrimitive() && c2.isPrimitive()) { |
| if((c1 == byte.class && c2 == char.class) || (c1 == char.class && c2 == byte.class)) { |
| // byte + char = int |
| return int.class; |
| } else if((c1 == short.class && c2 == char.class) || (c1 == char.class && c2 == short.class)) { |
| // short + char = int |
| return int.class; |
| } else if((c1 == int.class && c2 == float.class) || (c1 == float.class && c2 == int.class)) { |
| // int + float = double |
| return double.class; |
| } |
| } |
| // For all other cases. This will handle long + (float|double) = Number case as well as boolean + anything = Object case too. |
| return getMostSpecificCommonTypeUnequalNonprimitives(c1, c2); |
| } |
| |
| private static Class<?> getMostSpecificCommonTypeUnequalNonprimitives(final Class<?> c1, final Class<?> c2) { |
| final Class<?> npc1 = c1.isPrimitive() ? getWrapperType(c1) : c1; |
| final Class<?> npc2 = c2.isPrimitive() ? getWrapperType(c2) : c2; |
| final Set<Class<?>> a1 = getAssignables(npc1, npc2); |
| final Set<Class<?>> a2 = getAssignables(npc2, npc1); |
| a1.retainAll(a2); |
| if(a1.isEmpty()) { |
| // Can happen when at least one of the arguments is an interface, |
| // as they don't have Object at the root of their hierarchy. |
| return Object.class; |
| } |
| // Gather maximally specific elements. Yes, there can be more than one |
| // thank to interfaces. I.e., if you call this method for String.class |
| // and Number.class, you'll have Comparable, Serializable, and Object |
| // as maximal elements. |
| final List<Class<?>> max = new ArrayList<>(); |
| outer: for(final Class<?> clazz: a1) { |
| for(final Iterator<Class<?>> maxiter = max.iterator(); maxiter.hasNext();) { |
| final Class<?> maxClazz = maxiter.next(); |
| if(isSubtype(maxClazz, clazz)) { |
| // It can't be maximal, if there's already a more specific |
| // maximal than it. |
| continue outer; |
| } |
| if(isSubtype(clazz, maxClazz)) { |
| // If it's more specific than a currently maximal element, |
| // that currently maximal is no longer a maximal. |
| maxiter.remove(); |
| } |
| } |
| // If we get here, no current maximal is more specific than the |
| // current class, so it is considered maximal as well |
| max.add(clazz); |
| } |
| if(max.size() > 1) { |
| return Object.class; |
| } |
| return max.get(0); |
| } |
| |
| private static Set<Class<?>> getAssignables(final Class<?> c1, final Class<?> c2) { |
| final Set<Class<?>> s = new HashSet<>(); |
| collectAssignables(c1, c2, s); |
| return s; |
| } |
| |
| private static void collectAssignables(final Class<?> c1, final Class<?> c2, final Set<Class<?>> s) { |
| if(c1.isAssignableFrom(c2)) { |
| s.add(c1); |
| } |
| final Class<?> sc = c1.getSuperclass(); |
| if(sc != null) { |
| collectAssignables(sc, c2, s); |
| } |
| final Class<?>[] itf = c1.getInterfaces(); |
| for(int i = 0; i < itf.length; ++i) { |
| collectAssignables(itf[i], c2, s); |
| } |
| } |
| |
| private static final Map<Class<?>, Class<?>> WRAPPER_TYPES = createWrapperTypes(); |
| private static final Map<Class<?>, Class<?>> PRIMITIVE_TYPES = invertMap(WRAPPER_TYPES); |
| private static final Map<String, Class<?>> PRIMITIVE_TYPES_BY_NAME = createClassNameMapping(WRAPPER_TYPES.keySet()); |
| |
| private static Map<Class<?>, Class<?>> createWrapperTypes() { |
| final Map<Class<?>, Class<?>> wrapperTypes = new IdentityHashMap<>(8); |
| wrapperTypes.put(Boolean.TYPE, Boolean.class); |
| wrapperTypes.put(Byte.TYPE, Byte.class); |
| wrapperTypes.put(Character.TYPE, Character.class); |
| wrapperTypes.put(Short.TYPE, Short.class); |
| wrapperTypes.put(Integer.TYPE, Integer.class); |
| wrapperTypes.put(Long.TYPE, Long.class); |
| wrapperTypes.put(Float.TYPE, Float.class); |
| wrapperTypes.put(Double.TYPE, Double.class); |
| return Collections.unmodifiableMap(wrapperTypes); |
| } |
| |
| private static Map<String, Class<?>> createClassNameMapping(final Collection<Class<?>> classes) { |
| final Map<String, Class<?>> map = new HashMap<>(); |
| for(final Class<?> clazz: classes) { |
| map.put(clazz.getName(), clazz); |
| } |
| return map; |
| } |
| |
| private static <K, V> Map<V, K> invertMap(final Map<K, V> map) { |
| final Map<V, K> inverted = new IdentityHashMap<>(map.size()); |
| for(final Map.Entry<K, V> entry: map.entrySet()) { |
| inverted.put(entry.getValue(), entry.getKey()); |
| } |
| return Collections.unmodifiableMap(inverted); |
| } |
| |
| /** |
| * Determines whether one type can be converted to another type using a method invocation conversion, as per JLS 5.3 |
| * "Method Invocation Conversion". This is basically all conversions allowed by subtyping (see |
| * {@link #isSubtype(Class, Class)}) as well as boxing conversion (JLS 5.1.7) optionally followed by widening |
| * reference conversion and unboxing conversion (JLS 5.1.8) optionally followed by widening primitive conversion. |
| * |
| * @param sourceType the type being converted from (call site type for parameter types, method type for return types) |
| * @param targetType the parameter type being converted to (method type for parameter types, call site type for return types) |
| * @return true if source type is method invocation convertible to target type. |
| */ |
| public static boolean isMethodInvocationConvertible(final Class<?> sourceType, final Class<?> targetType) { |
| if(targetType.isAssignableFrom(sourceType)) { |
| return true; |
| } |
| if(sourceType.isPrimitive()) { |
| if(targetType.isPrimitive()) { |
| return isProperPrimitiveSubtype(sourceType, targetType); |
| } |
| // Boxing + widening reference conversion |
| assert WRAPPER_TYPES.get(sourceType) != null : sourceType.getName(); |
| return targetType.isAssignableFrom(WRAPPER_TYPES.get(sourceType)); |
| } |
| if(targetType.isPrimitive()) { |
| final Class<?> unboxedCallSiteType = PRIMITIVE_TYPES.get(sourceType); |
| return unboxedCallSiteType != null |
| && (unboxedCallSiteType == targetType || isProperPrimitiveSubtype(unboxedCallSiteType, targetType)); |
| } |
| return false; |
| } |
| |
| /** |
| * Determines whether a type can be converted to another without losing any precision. As a special case, |
| * void is considered convertible only to Object and void, while anything can be converted to void. This |
| * is because a target type of void means we don't care about the value, so the conversion is always |
| * permissible. |
| * |
| * @param sourceType the source type |
| * @param targetType the target type |
| * @return true if lossless conversion is possible |
| */ |
| public static boolean isConvertibleWithoutLoss(final Class<?> sourceType, final Class<?> targetType) { |
| if(targetType.isAssignableFrom(sourceType) || targetType == void.class) { |
| return true; |
| } |
| if(sourceType.isPrimitive()) { |
| if(sourceType == void.class) { |
| // Void should be losslessly representable by Object, either as null or as a custom value that |
| // can be set with DynamicLinkerFactory.setAutoConversionStrategy. |
| return targetType == Object.class; |
| } |
| if(targetType.isPrimitive()) { |
| return isProperPrimitiveLosslessSubtype(sourceType, targetType); |
| } |
| // Boxing + widening reference conversion |
| assert WRAPPER_TYPES.get(sourceType) != null : sourceType.getName(); |
| return targetType.isAssignableFrom(WRAPPER_TYPES.get(sourceType)); |
| } |
| // Can't convert from any non-primitive type to any primitive type without data loss because of null. |
| // Also, can't convert non-assignable reference types. |
| return false; |
| } |
| |
| /** |
| * Determines whether one type can be potentially converted to another type at runtime. Allows a conversion between |
| * any subtype and supertype in either direction, and also allows a conversion between any two primitive types, as |
| * well as between any primitive type and any reference type that can hold a boxed primitive. |
| * |
| * @param callSiteType the parameter type at the call site |
| * @param methodType the parameter type in the method declaration |
| * @return true if callSiteType is potentially convertible to the methodType. |
| */ |
| public static boolean isPotentiallyConvertible(final Class<?> callSiteType, final Class<?> methodType) { |
| // Widening or narrowing reference conversion |
| if(areAssignable(callSiteType, methodType)) { |
| return true; |
| } |
| if(callSiteType.isPrimitive()) { |
| // Allow any conversion among primitives, as well as from any |
| // primitive to any type that can receive a boxed primitive. |
| // TODO: narrow this a bit, i.e. allow, say, boolean to Character? |
| // MethodHandles.convertArguments() allows it, so we might need to |
| // too. |
| return methodType.isPrimitive() || isAssignableFromBoxedPrimitive(methodType); |
| } |
| if(methodType.isPrimitive()) { |
| // Allow conversion from any reference type that can contain a |
| // boxed primitive to any primitive. |
| // TODO: narrow this a bit too? |
| return isAssignableFromBoxedPrimitive(callSiteType); |
| } |
| return false; |
| } |
| |
| /** |
| * Returns true if either of the types is assignable from the other. |
| * @param c1 one of the types |
| * @param c2 another one of the types |
| * @return true if either c1 is assignable from c2 or c2 is assignable from c1. |
| */ |
| public static boolean areAssignable(final Class<?> c1, final Class<?> c2) { |
| return c1.isAssignableFrom(c2) || c2.isAssignableFrom(c1); |
| } |
| |
| /** |
| * Determines whether one type is a subtype of another type, as per JLS 4.10 "Subtyping". Note: this is not strict |
| * or proper subtype, therefore true is also returned for identical types; to be completely precise, it allows |
| * identity conversion (JLS 5.1.1), widening primitive conversion (JLS 5.1.2) and widening reference conversion (JLS |
| * 5.1.5). |
| * |
| * @param subType the supposed subtype |
| * @param superType the supposed supertype of the subtype |
| * @return true if subType can be converted by identity conversion, widening primitive conversion, or widening |
| * reference conversion to superType. |
| */ |
| public static boolean isSubtype(final Class<?> subType, final Class<?> superType) { |
| // Covers both JLS 4.10.2 "Subtyping among Class and Interface Types" |
| // and JLS 4.10.3 "Subtyping among Array Types", as well as primitive |
| // type identity. |
| if(superType.isAssignableFrom(subType)) { |
| return true; |
| } |
| // JLS 4.10.1 "Subtyping among Primitive Types". Note we don't test for |
| // identity, as identical types were taken care of in the |
| // isAssignableFrom test. As per 4.10.1, the supertype relation is as |
| // follows: |
| // double > float |
| // float > long |
| // long > int |
| // int > short |
| // int > char |
| // short > byte |
| if(superType.isPrimitive() && subType.isPrimitive()) { |
| return isProperPrimitiveSubtype(subType, superType); |
| } |
| return false; |
| } |
| |
| /** |
| * Returns true if a supposed primitive subtype is a proper subtype ( meaning, subtype and not identical) of the |
| * supposed primitive supertype |
| * |
| * @param subType the supposed subtype |
| * @param superType the supposed supertype |
| * @return true if subType is a proper (not identical to) primitive subtype of the superType |
| */ |
| private static boolean isProperPrimitiveSubtype(final Class<?> subType, final Class<?> superType) { |
| if(superType == boolean.class || subType == boolean.class) { |
| return false; |
| } |
| if(subType == byte.class) { |
| return superType != char.class; |
| } |
| if(subType == char.class) { |
| return superType != short.class && superType != byte.class; |
| } |
| if(subType == short.class) { |
| return superType != char.class && superType != byte.class; |
| } |
| if(subType == int.class) { |
| return superType == long.class || superType == float.class || superType == double.class; |
| } |
| if(subType == long.class) { |
| return superType == float.class || superType == double.class; |
| } |
| if(subType == float.class) { |
| return superType == double.class; |
| } |
| return false; |
| } |
| |
| /** |
| * Similar to {@link #isProperPrimitiveSubtype(Class, Class)}, except it disallows conversions from int and long to |
| * float, and from long to double, as those can lose precision. It also disallows conversion from and to char and |
| * anything else (similar to boolean) as char is not meant to be an arithmetic type. |
| * @param subType the supposed subtype |
| * @param superType the supposed supertype |
| * @return true if subType is a proper (not identical to) primitive subtype of the superType that can be represented |
| * by the supertype without no precision loss. |
| */ |
| private static boolean isProperPrimitiveLosslessSubtype(final Class<?> subType, final Class<?> superType) { |
| if(superType == boolean.class || subType == boolean.class) { |
| return false; |
| } |
| if(superType == char.class || subType == char.class) { |
| return false; |
| } |
| if(subType == byte.class) { |
| return true; |
| } |
| if(subType == short.class) { |
| return superType != byte.class; |
| } |
| if(subType == int.class) { |
| return superType == long.class || superType == double.class; |
| } |
| if(subType == float.class) { |
| return superType == double.class; |
| } |
| return false; |
| } |
| |
| private static final Map<Class<?>, Class<?>> WRAPPER_TO_PRIMITIVE_TYPES = createWrapperToPrimitiveTypes(); |
| |
| private static Map<Class<?>, Class<?>> createWrapperToPrimitiveTypes() { |
| final Map<Class<?>, Class<?>> classes = new IdentityHashMap<>(); |
| classes.put(Void.class, Void.TYPE); |
| classes.put(Boolean.class, Boolean.TYPE); |
| classes.put(Byte.class, Byte.TYPE); |
| classes.put(Character.class, Character.TYPE); |
| classes.put(Short.class, Short.TYPE); |
| classes.put(Integer.class, Integer.TYPE); |
| classes.put(Long.class, Long.TYPE); |
| classes.put(Float.class, Float.TYPE); |
| classes.put(Double.class, Double.TYPE); |
| return classes; |
| } |
| |
| private static final Set<Class<?>> PRIMITIVE_WRAPPER_TYPES = createPrimitiveWrapperTypes(); |
| |
| private static Set<Class<?>> createPrimitiveWrapperTypes() { |
| final Map<Class<?>, Class<?>> classes = new IdentityHashMap<>(); |
| addClassHierarchy(classes, Boolean.class); |
| addClassHierarchy(classes, Byte.class); |
| addClassHierarchy(classes, Character.class); |
| addClassHierarchy(classes, Short.class); |
| addClassHierarchy(classes, Integer.class); |
| addClassHierarchy(classes, Long.class); |
| addClassHierarchy(classes, Float.class); |
| addClassHierarchy(classes, Double.class); |
| return classes.keySet(); |
| } |
| |
| private static void addClassHierarchy(final Map<Class<?>, Class<?>> map, final Class<?> clazz) { |
| if(clazz == null) { |
| return; |
| } |
| map.put(clazz, clazz); |
| addClassHierarchy(map, clazz.getSuperclass()); |
| for(final Class<?> itf: clazz.getInterfaces()) { |
| addClassHierarchy(map, itf); |
| } |
| } |
| |
| /** |
| * Returns true if the class can be assigned from any boxed primitive. |
| * |
| * @param clazz the class |
| * @return true if the class can be assigned from any boxed primitive. Basically, it is true if the class is any |
| * primitive wrapper class, or a superclass or superinterface of any primitive wrapper class. |
| */ |
| private static boolean isAssignableFromBoxedPrimitive(final Class<?> clazz) { |
| return PRIMITIVE_WRAPPER_TYPES.contains(clazz); |
| } |
| |
| /** |
| * Given a name of a primitive type (except "void"), returns the class representing it. I.e. when invoked with |
| * "int", returns {@link Integer#TYPE}. |
| * @param name the name of the primitive type |
| * @return the class representing the primitive type, or null if the name does not correspond to a primitive type |
| * or is "void". |
| */ |
| public static Class<?> getPrimitiveTypeByName(final String name) { |
| return PRIMITIVE_TYPES_BY_NAME.get(name); |
| } |
| |
| /** |
| * When passed a class representing a wrapper for a primitive type, returns the class representing the corresponding |
| * primitive type. I.e. calling it with {@code Integer.class} will return {@code Integer.TYPE}. If passed a class |
| * that is not a wrapper for primitive type, returns null. |
| * @param wrapperType the class object representing a wrapper for a primitive type |
| * @return the class object representing the primitive type, or null if the passed class is not a primitive wrapper. |
| */ |
| public static Class<?> getPrimitiveType(final Class<?> wrapperType) { |
| return WRAPPER_TO_PRIMITIVE_TYPES.get(wrapperType); |
| } |
| |
| |
| /** |
| * When passed a class representing a primitive type, returns the class representing the corresponding |
| * wrapper type. I.e. calling it with {@code int.class} will return {@code Integer.class}. If passed a class |
| * that is not a primitive type, returns null. |
| * @param primitiveType the class object representing a primitive type |
| * @return the class object representing the wrapper type, or null if the passed class is not a primitive. |
| */ |
| public static Class<?> getWrapperType(final Class<?> primitiveType) { |
| return WRAPPER_TYPES.get(primitiveType); |
| } |
| |
| /** |
| * Returns true if the passed type is a wrapper for a primitive type. |
| * @param type the examined type |
| * @return true if the passed type is a wrapper for a primitive type. |
| */ |
| public static boolean isWrapperType(final Class<?> type) { |
| return PRIMITIVE_TYPES.containsKey(type); |
| } |
| } |
