--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/src/jdk/internal/dynalink/beans/MaximallySpecific.java Thu Feb 14 13:22:26 2013 +0100
@@ -0,0 +1,211 @@
+/*
+ * 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.beans;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodType;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import jdk.internal.dynalink.linker.ConversionComparator.Comparison;
+import jdk.internal.dynalink.linker.LinkerServices;
+import jdk.internal.dynalink.support.TypeUtilities;
+
+
+/**
+ * Utility class that encapsulates the algorithm for choosing the maximally specific methods.
+ *
+ * @author Attila Szegedi
+ */
+class MaximallySpecific {
+ /**
+ * Given a list of methods, returns a list of maximally specific methods.
+ *
+ * @param methods the list of methods
+ * @param varArgs whether to assume the methods are varargs
+ * @return the list of maximally specific methods.
+ */
+ static List<MethodHandle> getMaximallySpecificMethods(List<MethodHandle> methods, boolean varArgs) {
+ return getMaximallySpecificMethods(methods, varArgs, null, null);
+ }
+
+ /**
+ * Given a list of methods, returns a list of maximally specific methods, applying language-runtime specific
+ * conversion preferences.
+ *
+ * @param methods the list of methods
+ * @param varArgs whether to assume the methods are varargs
+ * @param argTypes concrete argument types for the invocation
+ * @return the list of maximally specific methods.
+ */
+ static List<MethodHandle> getMaximallySpecificMethods(List<MethodHandle> methods, boolean varArgs,
+ Class<?>[] argTypes, LinkerServices ls) {
+ if(methods.size() < 2) {
+ return methods;
+ }
+ final LinkedList<MethodHandle> maximals = new LinkedList<>();
+ for(MethodHandle m: methods) {
+ final MethodType methodType = m.type();
+ boolean lessSpecific = false;
+ for(Iterator<MethodHandle> maximal = maximals.iterator(); maximal.hasNext();) {
+ final MethodHandle max = maximal.next();
+ switch(isMoreSpecific(methodType, max.type(), varArgs, argTypes, ls)) {
+ case TYPE_1_BETTER: {
+ maximal.remove();
+ break;
+ }
+ case TYPE_2_BETTER: {
+ lessSpecific = true;
+ break;
+ }
+ case INDETERMINATE: {
+ // do nothing
+ }
+ }
+ }
+ if(!lessSpecific) {
+ maximals.addLast(m);
+ }
+ }
+ return maximals;
+ }
+
+ private static Comparison isMoreSpecific(MethodType t1, MethodType t2, boolean varArgs, Class<?>[] argTypes,
+ LinkerServices ls) {
+ final int pc1 = t1.parameterCount();
+ final int pc2 = t2.parameterCount();
+ assert varArgs || (pc1 == pc2) && (argTypes == null || argTypes.length == pc1);
+ assert (argTypes == null) == (ls == null);
+ final int maxPc = Math.max(Math.max(pc1, pc2), argTypes == null ? 0 : argTypes.length);
+ boolean t1MoreSpecific = false;
+ boolean t2MoreSpecific = false;
+ // NOTE: Starting from 1 as overloaded method resolution doesn't depend on 0th element, which is the type of
+ // 'this'. We're only dealing with instance methods here, not static methods. Actually, static methods will have
+ // a fake 'this' of type StaticClass.
+ for(int i = 1; i < maxPc; ++i) {
+ final Class<?> c1 = getParameterClass(t1, pc1, i, varArgs);
+ final Class<?> c2 = getParameterClass(t2, pc2, i, varArgs);
+ if(c1 != c2) {
+ final Comparison cmp = compare(c1, c2, argTypes, i, ls);
+ if(cmp == Comparison.TYPE_1_BETTER && !t1MoreSpecific) {
+ t1MoreSpecific = true;
+ if(t2MoreSpecific) {
+ return Comparison.INDETERMINATE;
+ }
+ }
+ if(cmp == Comparison.TYPE_2_BETTER && !t2MoreSpecific) {
+ t2MoreSpecific = true;
+ if(t1MoreSpecific) {
+ return Comparison.INDETERMINATE;
+ }
+ }
+ }
+ }
+ if(t1MoreSpecific) {
+ return Comparison.TYPE_1_BETTER;
+ } else if(t2MoreSpecific) {
+ return Comparison.TYPE_2_BETTER;
+ }
+ return Comparison.INDETERMINATE;
+ }
+
+ private static Comparison compare(Class<?> c1, Class<?> c2, Class<?>[] argTypes, int i, LinkerServices cmp) {
+ if(cmp != null) {
+ final Comparison c = cmp.compareConversion(argTypes[i], c1, c2);
+ if(c != Comparison.INDETERMINATE) {
+ return c;
+ }
+ }
+ if(TypeUtilities.isSubtype(c1, c2)) {
+ return Comparison.TYPE_1_BETTER;
+ } if(TypeUtilities.isSubtype(c2, c1)) {
+ return Comparison.TYPE_2_BETTER;
+ }
+ return Comparison.INDETERMINATE;
+ }
+
+ private static Class<?> getParameterClass(MethodType t, int l, int i, boolean varArgs) {
+ return varArgs && i >= l - 1 ? t.parameterType(l - 1).getComponentType() : t.parameterType(i);
+ }
+}