Mercurial > jdk8-mips64-public > nashorn / file comparison

comparison: src/jdk/internal/dynalink/beans/SimpleDynamicMethod.java

src/jdk/internal/dynalink/beans/SimpleDynamicMethod.java

changeset 90
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89:43e32b36153c 90:5a820fb11814
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 */
25
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
35
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.
39
40 You may not use this file except in compliance with either the Apache
41 License or the BSD License.
42
43 If you choose to use this file in compliance with the Apache License, the
44 following notice applies to you:
45
46 You may obtain a copy of the Apache License at
47
48 http://www.apache.org/licenses/LICENSE-2.0
49
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.
55
56 If you choose to use this file in compliance with the BSD License, the
57 following notice applies to you:
58
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.
70
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 */
83
84 package jdk.internal.dynalink.beans;
85
86 import java.lang.invoke.MethodHandle;
87 import java.lang.invoke.MethodHandles;
88 import java.lang.invoke.MethodType;
89 import java.lang.reflect.Array;
90 import jdk.internal.dynalink.linker.LinkerServices;
91 import jdk.internal.dynalink.support.Guards;
92
93
94 /**
95 * A dynamic method bound to exactly one, non-overloaded Java method. Handles varargs.
96 *
97 * @author Attila Szegedi
98 */
99 class SimpleDynamicMethod extends DynamicMethod {
100 private final MethodHandle target;
101
102 /**
103 * Creates a simple dynamic method with no name.
104 * @param target the target method handle
105 */
106 SimpleDynamicMethod(MethodHandle target) {
107 this(target, null);
108 }
109
110 /**
111 * Creates a new simple dynamic method, with a name constructed from the class name, method name, and handle
112 * signature.
113 *
114 * @param target the target method handle
115 * @param clazz the class declaring the method
116 * @param name the simple name of the method
117 */
118 SimpleDynamicMethod(MethodHandle target, Class<?> clazz, String name) {
119 this(target, getName(target, clazz, name));
120 }
121
122 SimpleDynamicMethod(MethodHandle target, String name) {
123 super(name);
124 this.target = target;
125 }
126
127 private static String getName(MethodHandle target, Class<?> clazz, String name) {
128 return getMethodNameWithSignature(target, getClassAndMethodName(clazz, name));
129 }
130
131 static String getMethodNameWithSignature(MethodHandle target, String methodName) {
132 final String typeStr = target.type().toString();
133 final int retTypeIndex = typeStr.lastIndexOf(')') + 1;
134 int secondParamIndex = typeStr.indexOf(',') + 1;
135 if(secondParamIndex == 0) {
136 secondParamIndex = retTypeIndex - 1;
137 }
138 return typeStr.substring(retTypeIndex) + " " + methodName + "(" + typeStr.substring(secondParamIndex, retTypeIndex);
139 }
140
141 /**
142 * Returns the target of this dynamic method
143 *
144 * @return the target of this dynamic method
145 */
146 MethodHandle getTarget() {
147 return target;
148 }
149
150 @Override
151 SimpleDynamicMethod getMethodForExactParamTypes(String paramTypes) {
152 return typeMatchesDescription(paramTypes, target.type()) ? this : null;
153 }
154
155 @Override
156 MethodHandle getInvocation(MethodType callSiteType, LinkerServices linkerServices) {
157 final MethodType methodType = target.type();
158 final int paramsLen = methodType.parameterCount();
159 final boolean varArgs = target.isVarargsCollector();
160 final MethodHandle fixTarget = varArgs ? target.asFixedArity() : target;
161 final int fixParamsLen = varArgs ? paramsLen - 1 : paramsLen;
162 final int argsLen = callSiteType.parameterCount();
163 if(argsLen < fixParamsLen) {
164 // Less actual arguments than number of fixed declared arguments; can't invoke.
165 return null;
166 }
167 // Method handle of the same number of arguments as the call site type
168 if(argsLen == fixParamsLen) {
169 // Method handle that matches the number of actual arguments as the number of fixed arguments
170 final MethodHandle matchedMethod;
171 if(varArgs) {
172 // If vararg, add a zero-length array of the expected type as the last argument to signify no variable
173 // arguments.
174 // TODO: check whether collectArguments() would handle this too.
175 matchedMethod = MethodHandles.insertArguments(fixTarget, fixParamsLen, Array.newInstance(
176 methodType.parameterType(fixParamsLen).getComponentType(), 0));
177 } else {
178 // Otherwise, just use the method
179 matchedMethod = fixTarget;
180 }
181 return createConvertingInvocation(matchedMethod, linkerServices, callSiteType);
182 }
183
184 // What's below only works for varargs
185 if(!varArgs) {
186 return null;
187 }
188
189 final Class<?> varArgType = methodType.parameterType(fixParamsLen);
190 // Handle a somewhat sinister corner case: caller passes exactly one argument in the vararg position, and we
191 // must handle both a prepacked vararg array as well as a genuine 1-long vararg sequence.
192 if(argsLen == paramsLen) {
193 final Class<?> callSiteLastArgType = callSiteType.parameterType(fixParamsLen);
194 if(varArgType.isAssignableFrom(callSiteLastArgType)) {
195 // Call site signature guarantees we'll always be passed a single compatible array; just link directly
196 // to the method.
197 return createConvertingInvocation(fixTarget, linkerServices, callSiteType);
198 } else if(!linkerServices.canConvert(callSiteLastArgType, varArgType)) {
199 // Call site signature guarantees the argument can definitely not be an array (i.e. it is primitive);
200 // link immediately to a vararg-packing method handle.
201 return createConvertingInvocation(collectArguments(fixTarget, argsLen), linkerServices, callSiteType);
202 } else {
203 // Call site signature makes no guarantees that the single argument in the vararg position will be
204 // compatible across all invocations. Need to insert an appropriate guard and fall back to generic
205 // vararg method when it is not.
206 return MethodHandles.guardWithTest(Guards.isInstance(varArgType, fixParamsLen, callSiteType),
207 createConvertingInvocation(fixTarget, linkerServices, callSiteType),
208 createConvertingInvocation(collectArguments(fixTarget, argsLen), linkerServices, callSiteType));
209 }
210 } else {
211 // Remaining case: more than one vararg.
212 return createConvertingInvocation(collectArguments(fixTarget, argsLen), linkerServices, callSiteType);
213 }
214 }
215
216 @Override
217 public boolean contains(MethodHandle mh) {
218 return target.type().parameterList().equals(mh.type().parameterList());
219 }
220
221 /**
222 * Creates a method handle out of the original target that will collect the varargs for the exact component type of
223 * the varArg array. Note that this will nicely trigger language-specific type converters for exactly those varargs
224 * for which it is necessary when later passed to linkerServices.convertArguments().
225 *
226 * @param target the original method handle
227 * @param parameterCount the total number of arguments in the new method handle
228 * @return a collecting method handle
229 */
230 static MethodHandle collectArguments(MethodHandle target, final int parameterCount) {
231 final MethodType methodType = target.type();
232 final int fixParamsLen = methodType.parameterCount() - 1;
233 final Class<?> arrayType = methodType.parameterType(fixParamsLen);
234 return target.asCollector(arrayType, parameterCount - fixParamsLen);
235 }
236
237 private static MethodHandle createConvertingInvocation(final MethodHandle sizedMethod,
238 final LinkerServices linkerServices, final MethodType callSiteType) {
239 return linkerServices.asType(sizedMethod, callSiteType);
240 }
241 }

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