Mon, 18 Feb 2013 16:00:15 +0100
8008371: Fix Dynalink compiler warnings and whitespace
Reviewed-by: jlaskey, sundar
1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
26 /*
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file, and Oracle licenses the original version of this file under the BSD
31 * license:
32 */
33 /*
34 Copyright 2009-2013 Attila Szegedi
36 Licensed under both the Apache License, Version 2.0 (the "Apache License")
37 and the BSD License (the "BSD License"), with licensee being free to
38 choose either of the two at their discretion.
40 You may not use this file except in compliance with either the Apache
41 License or the BSD License.
43 If you choose to use this file in compliance with the Apache License, the
44 following notice applies to you:
46 You may obtain a copy of the Apache License at
48 http://www.apache.org/licenses/LICENSE-2.0
50 Unless required by applicable law or agreed to in writing, software
51 distributed under the License is distributed on an "AS IS" BASIS,
52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
53 implied. See the License for the specific language governing
54 permissions and limitations under the License.
56 If you choose to use this file in compliance with the BSD License, the
57 following notice applies to you:
59 Redistribution and use in source and binary forms, with or without
60 modification, are permitted provided that the following conditions are
61 met:
62 * Redistributions of source code must retain the above copyright
63 notice, this list of conditions and the following disclaimer.
64 * Redistributions in binary form must reproduce the above copyright
65 notice, this list of conditions and the following disclaimer in the
66 documentation and/or other materials provided with the distribution.
67 * Neither the name of the copyright holder nor the names of
68 contributors may be used to endorse or promote products derived from
69 this software without specific prior written permission.
71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
82 */
84 package jdk.internal.dynalink.beans;
86 import java.lang.invoke.MethodHandle;
87 import java.lang.invoke.MethodType;
88 import java.util.Iterator;
89 import java.util.LinkedList;
90 import java.util.List;
91 import jdk.internal.dynalink.linker.ConversionComparator.Comparison;
92 import jdk.internal.dynalink.linker.LinkerServices;
93 import jdk.internal.dynalink.support.TypeUtilities;
95 /**
96 * Utility class that encapsulates the algorithm for choosing the maximally specific methods.
97 *
98 * @author Attila Szegedi
99 */
100 class MaximallySpecific {
101 /**
102 * Given a list of methods, returns a list of maximally specific methods.
103 *
104 * @param methods the list of methods
105 * @param varArgs whether to assume the methods are varargs
106 * @return the list of maximally specific methods.
107 */
108 static List<MethodHandle> getMaximallySpecificMethods(List<MethodHandle> methods, boolean varArgs) {
109 return getMaximallySpecificMethods(methods, varArgs, null, null);
110 }
112 /**
113 * Given a list of methods, returns a list of maximally specific methods, applying language-runtime specific
114 * conversion preferences.
115 *
116 * @param methods the list of methods
117 * @param varArgs whether to assume the methods are varargs
118 * @param argTypes concrete argument types for the invocation
119 * @return the list of maximally specific methods.
120 */
121 static List<MethodHandle> getMaximallySpecificMethods(List<MethodHandle> methods, boolean varArgs,
122 Class<?>[] argTypes, LinkerServices ls) {
123 if(methods.size() < 2) {
124 return methods;
125 }
126 final LinkedList<MethodHandle> maximals = new LinkedList<>();
127 for(MethodHandle m: methods) {
128 final MethodType methodType = m.type();
129 boolean lessSpecific = false;
130 for(Iterator<MethodHandle> maximal = maximals.iterator(); maximal.hasNext();) {
131 final MethodHandle max = maximal.next();
132 switch(isMoreSpecific(methodType, max.type(), varArgs, argTypes, ls)) {
133 case TYPE_1_BETTER: {
134 maximal.remove();
135 break;
136 }
137 case TYPE_2_BETTER: {
138 lessSpecific = true;
139 break;
140 }
141 case INDETERMINATE: {
142 // do nothing
143 break;
144 }
145 default: {
146 throw new AssertionError();
147 }
148 }
149 }
150 if(!lessSpecific) {
151 maximals.addLast(m);
152 }
153 }
154 return maximals;
155 }
157 private static Comparison isMoreSpecific(MethodType t1, MethodType t2, boolean varArgs, Class<?>[] argTypes,
158 LinkerServices ls) {
159 final int pc1 = t1.parameterCount();
160 final int pc2 = t2.parameterCount();
161 assert varArgs || (pc1 == pc2) && (argTypes == null || argTypes.length == pc1);
162 assert (argTypes == null) == (ls == null);
163 final int maxPc = Math.max(Math.max(pc1, pc2), argTypes == null ? 0 : argTypes.length);
164 boolean t1MoreSpecific = false;
165 boolean t2MoreSpecific = false;
166 // NOTE: Starting from 1 as overloaded method resolution doesn't depend on 0th element, which is the type of
167 // 'this'. We're only dealing with instance methods here, not static methods. Actually, static methods will have
168 // a fake 'this' of type StaticClass.
169 for(int i = 1; i < maxPc; ++i) {
170 final Class<?> c1 = getParameterClass(t1, pc1, i, varArgs);
171 final Class<?> c2 = getParameterClass(t2, pc2, i, varArgs);
172 if(c1 != c2) {
173 final Comparison cmp = compare(c1, c2, argTypes, i, ls);
174 if(cmp == Comparison.TYPE_1_BETTER && !t1MoreSpecific) {
175 t1MoreSpecific = true;
176 if(t2MoreSpecific) {
177 return Comparison.INDETERMINATE;
178 }
179 }
180 if(cmp == Comparison.TYPE_2_BETTER && !t2MoreSpecific) {
181 t2MoreSpecific = true;
182 if(t1MoreSpecific) {
183 return Comparison.INDETERMINATE;
184 }
185 }
186 }
187 }
188 if(t1MoreSpecific) {
189 return Comparison.TYPE_1_BETTER;
190 } else if(t2MoreSpecific) {
191 return Comparison.TYPE_2_BETTER;
192 }
193 return Comparison.INDETERMINATE;
194 }
196 private static Comparison compare(Class<?> c1, Class<?> c2, Class<?>[] argTypes, int i, LinkerServices cmp) {
197 if(cmp != null) {
198 final Comparison c = cmp.compareConversion(argTypes[i], c1, c2);
199 if(c != Comparison.INDETERMINATE) {
200 return c;
201 }
202 }
203 if(TypeUtilities.isSubtype(c1, c2)) {
204 return Comparison.TYPE_1_BETTER;
205 } if(TypeUtilities.isSubtype(c2, c1)) {
206 return Comparison.TYPE_2_BETTER;
207 }
208 return Comparison.INDETERMINATE;
209 }
211 private static Class<?> getParameterClass(MethodType t, int l, int i, boolean varArgs) {
212 return varArgs && i >= l - 1 ? t.parameterType(l - 1).getComponentType() : t.parameterType(i);
213 }
214 }