Thu, 14 Feb 2013 13:22:26 +0100
8008085: Integrate Dynalink source code into Nashorn codebase
Reviewed-by: jlaskey, lagergren, 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
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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
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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.beans.ApplicableOverloadedMethods.ApplicabilityTest;
92 import jdk.internal.dynalink.linker.LinkerServices;
93 import jdk.internal.dynalink.support.TypeUtilities;
96 /**
97 * Represents an overloaded method.
98 *
99 * @author Attila Szegedi
100 */
101 class OverloadedDynamicMethod extends DynamicMethod {
102 /**
103 * Holds a list of all methods.
104 */
105 private final LinkedList<MethodHandle> methods;
106 private final ClassLoader classLoader;
108 /**
109 * Creates a new overloaded dynamic method.
110 *
111 * @param clazz the class this method belongs to
112 * @param name the name of the method
113 */
114 OverloadedDynamicMethod(Class<?> clazz, String name) {
115 this(new LinkedList<MethodHandle>(), clazz.getClassLoader(), getClassAndMethodName(clazz, name));
116 }
118 private OverloadedDynamicMethod(LinkedList<MethodHandle> methods, ClassLoader classLoader, String name) {
119 super(name);
120 this.methods = methods;
121 this.classLoader = classLoader;
122 }
124 @Override
125 SimpleDynamicMethod getMethodForExactParamTypes(String paramTypes) {
126 final LinkedList<MethodHandle> matchingMethods = new LinkedList<>();
127 for(MethodHandle method: methods) {
128 if(typeMatchesDescription(paramTypes, method.type())) {
129 matchingMethods.add(method);
130 }
131 }
132 switch(matchingMethods.size()) {
133 case 0: {
134 return null;
135 }
136 case 1: {
137 final MethodHandle target = matchingMethods.get(0);
138 return new SimpleDynamicMethod(target, SimpleDynamicMethod.getMethodNameWithSignature(target, getName()));
139 }
140 default: {
141 throw new BootstrapMethodError("Can't choose among " + matchingMethods + " for argument types "
142 + paramTypes + " for method " + getName());
143 }
144 }
145 }
147 @Override
148 public MethodHandle getInvocation(final MethodType callSiteType, final LinkerServices linkerServices) {
149 // First, find all methods applicable to the call site by subtyping (JLS 15.12.2.2)
150 final ApplicableOverloadedMethods subtypingApplicables = getApplicables(callSiteType,
151 ApplicableOverloadedMethods.APPLICABLE_BY_SUBTYPING);
152 // Next, find all methods applicable by method invocation conversion to the call site (JLS 15.12.2.3).
153 final ApplicableOverloadedMethods methodInvocationApplicables = getApplicables(callSiteType,
154 ApplicableOverloadedMethods.APPLICABLE_BY_METHOD_INVOCATION_CONVERSION);
155 // Finally, find all methods applicable by variable arity invocation. (JLS 15.12.2.4).
156 final ApplicableOverloadedMethods variableArityApplicables = getApplicables(callSiteType,
157 ApplicableOverloadedMethods.APPLICABLE_BY_VARIABLE_ARITY);
159 // Find the methods that are maximally specific based on the call site signature
160 List<MethodHandle> maximallySpecifics = subtypingApplicables.findMaximallySpecificMethods();
161 if(maximallySpecifics.isEmpty()) {
162 maximallySpecifics = methodInvocationApplicables.findMaximallySpecificMethods();
163 if(maximallySpecifics.isEmpty()) {
164 maximallySpecifics = variableArityApplicables.findMaximallySpecificMethods();
165 }
166 }
168 // Now, get a list of the rest of the methods; those that are *not* applicable to the call site signature based
169 // on JLS rules. As paradoxical as that might sound, we have to consider these for dynamic invocation, as they
170 // might match more concrete types passed in invocations. That's why we provisionally call them "invokables".
171 // This is typical for very generic signatures at call sites. Typical example: call site specifies
172 // (Object, Object), and we have a method whose parameter types are (String, int). None of the JLS applicability
173 // rules will trigger, but we must consider the method, as it can be the right match for a concrete invocation.
174 @SuppressWarnings({ "unchecked", "rawtypes" })
175 final List<MethodHandle> invokables = (List)methods.clone();
176 invokables.removeAll(subtypingApplicables.getMethods());
177 invokables.removeAll(methodInvocationApplicables.getMethods());
178 invokables.removeAll(variableArityApplicables.getMethods());
179 for(final Iterator<MethodHandle> it = invokables.iterator(); it.hasNext();) {
180 final MethodHandle m = it.next();
181 if(!isApplicableDynamically(linkerServices, callSiteType, m)) {
182 it.remove();
183 }
184 }
186 // If no additional methods can apply at invocation time, and there's more than one maximally specific method
187 // based on call site signature, that is a link-time ambiguity. In a static scenario, javac would report an
188 // ambiguity error.
189 if(invokables.isEmpty() && maximallySpecifics.size() > 1) {
190 throw new BootstrapMethodError("Can't choose among " + maximallySpecifics + " for argument types "
191 + callSiteType);
192 }
194 // Merge them all.
195 invokables.addAll(maximallySpecifics);
196 switch(invokables.size()) {
197 case 0: {
198 // No overloads can ever match the call site type
199 return null;
200 }
201 case 1: {
202 // Very lucky, we ended up with a single candidate method handle based on the call site signature; we
203 // can link it very simply by delegating to a SimpleDynamicMethod.
204 final MethodHandle mh = invokables.iterator().next();
205 return new SimpleDynamicMethod(mh).getInvocation(callSiteType, linkerServices);
206 }
207 }
209 // We have more than one candidate. We have no choice but to link to a method that resolves overloads on every
210 // invocation (alternatively, we could opportunistically link the one method that resolves for the current
211 // arguments, but we'd need to install a fairly complex guard for that and when it'd fail, we'd go back all the
212 // way to candidate selection.
213 // TODO: cache per call site type
214 return new OverloadedMethod(invokables, this, callSiteType, linkerServices).getInvoker();
215 }
217 @Override
218 public boolean contains(MethodHandle mh) {
219 final MethodType type = mh.type();
220 for(MethodHandle method: methods) {
221 if(typesEqualNoReceiver(type, method.type())) {
222 return true;
223 }
224 }
225 return false;
226 }
228 private static boolean typesEqualNoReceiver(MethodType type1, MethodType type2) {
229 final int pc = type1.parameterCount();
230 if(pc != type2.parameterCount()) {
231 return false;
232 }
233 for(int i = 1; i < pc; ++i) { // i = 1: ignore receiver
234 if(type1.parameterType(i) != type2.parameterType(i)) {
235 return false;
236 }
237 }
238 return true;
239 }
241 ClassLoader getClassLoader() {
242 return classLoader;
243 }
245 private static boolean isApplicableDynamically(LinkerServices linkerServices, MethodType callSiteType,
246 MethodHandle m) {
247 final MethodType methodType = m.type();
248 final boolean varArgs = m.isVarargsCollector();
249 final int fixedArgLen = methodType.parameterCount() - (varArgs ? 1 : 0);
250 final int callSiteArgLen = callSiteType.parameterCount();
251 if(varArgs) {
252 if(callSiteArgLen < fixedArgLen) {
253 return false;
254 }
255 } else if(callSiteArgLen != fixedArgLen) {
256 return false;
257 }
258 // Starting from 1, as receiver type doesn't participate
259 for(int i = 1; i < fixedArgLen; ++i) {
260 if(!isApplicableDynamically(linkerServices, callSiteType.parameterType(i), methodType.parameterType(i))) {
261 return false;
262 }
263 }
264 if(varArgs) {
265 final Class<?> varArgArrayType = methodType.parameterType(fixedArgLen);
266 final Class<?> varArgType = varArgArrayType.getComponentType();
267 if(fixedArgLen == callSiteArgLen - 1) {
268 final Class<?> callSiteArgType = callSiteType.parameterType(fixedArgLen);
269 // Exactly one vararg; check both exact matching and component
270 // matching.
271 return isApplicableDynamically(linkerServices, callSiteArgType, varArgArrayType)
272 || isApplicableDynamically(linkerServices, callSiteArgType, varArgType);
273 } else {
274 for(int i = fixedArgLen; i < callSiteArgLen; ++i) {
275 if(!isApplicableDynamically(linkerServices, callSiteType.parameterType(i), varArgType)) {
276 return false;
277 }
278 }
279 return true;
280 }
281 } else {
282 return true;
283 }
284 }
286 private static boolean isApplicableDynamically(LinkerServices linkerServices, Class<?> callSiteType,
287 Class<?> methodType) {
288 return TypeUtilities.isPotentiallyConvertible(callSiteType, methodType)
289 || linkerServices.canConvert(callSiteType, methodType);
290 }
292 private ApplicableOverloadedMethods getApplicables(MethodType callSiteType, ApplicabilityTest test) {
293 return new ApplicableOverloadedMethods(methods, callSiteType, test);
294 }
296 /**
297 * Add a method identified by a {@link SimpleDynamicMethod} to this overloaded method's set.
298 *
299 * @param method the method to add.
300 */
301 public void addMethod(SimpleDynamicMethod method) {
302 addMethod(method.getTarget());
303 }
305 /**
306 * Add a method to this overloaded method's set.
307 *
308 * @param method a method to add
309 */
310 public void addMethod(MethodHandle method) {
311 methods.add(method);
312 }
313 }