--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/src/jdk/internal/dynalink/support/TypeUtilities.java Thu Feb 14 13:22:26 2013 +0100
@@ -0,0 +1,442 @@
+/*
+ * 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 superclass or
+ * superinterface.
+ *
+ * @param c1 one type
+ * @param c2 another type
+ * @return their most common superclass or superinterface. 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<?> getMostSpecificCommonType(Class<?> c1, Class<?> c2) {
+ if(c1 == c2) {
+ return c1;
+ }
+ Class<?> c3 = c2;
+ if(c3.isPrimitive()) {
+ if(c3 == Byte.TYPE)
+ c3 = Byte.class;
+ else if(c3 == Short.TYPE)
+ c3 = Short.class;
+ else if(c3 == Character.TYPE)
+ c3 = Character.class;
+ else if(c3 == Integer.TYPE)
+ c3 = Integer.class;
+ else if(c3 == Float.TYPE)
+ c3 = Float.class;
+ else if(c3 == Long.TYPE)
+ c3 = Long.class;
+ else if(c3 == Double.TYPE)
+ c3 = Double.class;
+ }
+ Set<Class<?>> a1 = getAssignables(c1, c3);
+ Set<Class<?>> a2 = getAssignables(c3, c1);
+ 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.
+ List<Class<?>> max = new ArrayList<>();
+ outer: for(Class<?> clazz: a1) {
+ for(Iterator<Class<?>> maxiter = max.iterator(); maxiter.hasNext();) {
+ 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(Class<?> c1, Class<?> c2) {
+ Set<Class<?>> s = new HashSet<>();
+ collectAssignables(c1, c2, s);
+ return s;
+ }
+
+ private static void collectAssignables(Class<?> c1, Class<?> c2, Set<Class<?>> s) {
+ if(c1.isAssignableFrom(c2)) {
+ s.add(c1);
+ }
+ Class<?> sc = c1.getSuperclass();
+ if(sc != null) {
+ collectAssignables(sc, c2, s);
+ }
+ 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(Collection<Class<?>> classes) {
+ final Map<String, Class<?>> map = new HashMap<>();
+ for(Class<?> clazz: classes) {
+ map.put(clazz.getName(), clazz);
+ }
+ return map;
+ }
+
+ private static <K, V> Map<V, K> invertMap(Map<K, V> map) {
+ final Map<V, K> inverted = new IdentityHashMap<>(map.size());
+ for(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 callSiteType the parameter type at the call site
+ * @param methodType the parameter type in the method declaration
+ * @return true if callSiteType is method invocation convertible to the methodType.
+ */
+ public static boolean isMethodInvocationConvertible(Class<?> callSiteType, Class<?> methodType) {
+ if(methodType.isAssignableFrom(callSiteType)) {
+ return true;
+ }
+ if(callSiteType.isPrimitive()) {
+ if(methodType.isPrimitive()) {
+ return isProperPrimitiveSubtype(callSiteType, methodType);
+ }
+ // Boxing + widening reference conversion
+ return methodType.isAssignableFrom(WRAPPER_TYPES.get(callSiteType));
+ }
+ if(methodType.isPrimitive()) {
+ final Class<?> unboxedCallSiteType = PRIMITIVE_TYPES.get(callSiteType);
+ return unboxedCallSiteType != null
+ && (unboxedCallSiteType == methodType || isProperPrimitiveSubtype(unboxedCallSiteType, methodType));
+ }
+ 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(Class<?> callSiteType, Class<?> methodType) {
+ // Widening or narrowing reference conversion
+ if(methodType.isAssignableFrom(callSiteType) || callSiteType.isAssignableFrom(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;
+ }
+
+ /**
+ * 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(Class<?> subType, 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(Class<?> subType, 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;
+ }
+
+ 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(Map<Class<?>, Class<?>> map, Class<?> clazz) {
+ if(clazz == null) {
+ return;
+ }
+ map.put(clazz, clazz);
+ addClassHierarchy(map, clazz.getSuperclass());
+ for(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(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(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(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(Class<?> primitiveType) {
+ return WRAPPER_TYPES.get(primitiveType);
+ }
+}
\ No newline at end of file