--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/internal/InternalTypeUtilities.java Wed Jul 05 21:04:26 2017 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,187 +0,0 @@
-/*
- * Copyright (c) 2015, 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.
- */
-package jdk.internal.dynalink.internal;
-
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Set;
-import jdk.internal.dynalink.linker.support.TypeUtilities;
-
-/**
- * Various static utility methods for testing type relationships; internal to Dynalink.
- */
-public class InternalTypeUtilities {
- private InternalTypeUtilities() {
- }
-
- /**
- * Returns true if either of the types is assignable from the other.
- * @param c1 one type
- * @param c2 another type
- * @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);
- }
-
- /**
- * Return true if it is safe to strongly reference a class from the referred
- * class loader from a class associated with the referring class loader
- * without risking a class loader memory leak. Generally, it is only safe
- * to reference classes from the same or ancestor class loader. {@code null}
- * indicates the system class loader; classes from it can always be
- * directly referenced, and it can only directly reference classes from
- * itself. This method can be used by language runtimes to ensure they are
- * using weak references in their linkages when they need to link to methods
- * in unrelated class loaders.
- *
- * @param referrerLoader the referrer class loader.
- * @param referredLoader the referred class loader
- * @return true if it is safe to strongly reference the class from referred
- * in referred.
- * @throws SecurityException if the caller does not have the
- * {@code RuntimePermission("getClassLoader")} permission and the method
- * needs to traverse the parent class loader chain.
- */
- public static boolean canReferenceDirectly(final ClassLoader referrerLoader, final ClassLoader referredLoader) {
- if(referredLoader == null) {
- // Can always refer directly to a system class
- return true;
- }
- if(referrerLoader == null) {
- // System classes can't refer directly to any non-system class
- return false;
- }
- // Otherwise, can only refer directly to classes residing in same or
- // parent class loader.
-
- ClassLoader referrer = referrerLoader;
- do {
- if(referrer == referredLoader) {
- return true;
- }
- referrer = referrer.getParent();
- } while(referrer != null);
- return false;
- }
-
- /**
- * 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(TypeUtilities.isConvertibleWithoutLoss(c2, c1)) {
- return c1;
- } else if(TypeUtilities.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() ? TypeUtilities.getWrapperType(c1) : c1;
- final Class<?> npc2 = c2.isPrimitive() ? TypeUtilities.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(TypeUtilities.isSubtype(maxClazz, clazz)) {
- // It can't be maximal, if there's already a more specific
- // maximal than it.
- continue outer;
- }
- if(TypeUtilities.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);
- }
- }
-}