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 package jdk.nashorn.internal.runtime.linker;
27
28 import java.lang.invoke.MethodHandle;
29 import java.lang.invoke.MethodHandles;
30 import java.lang.invoke.MethodType;
31 import java.util.HashMap;
32 import java.util.Map;
33 import jdk.internal.dynalink.CallSiteDescriptor;
34 import jdk.internal.dynalink.linker.GuardedInvocation;
35 import jdk.internal.dynalink.linker.GuardedTypeConversion;
36 import jdk.internal.dynalink.linker.GuardingTypeConverterFactory;
37 import jdk.internal.dynalink.linker.LinkRequest;
38 import jdk.internal.dynalink.linker.LinkerServices;
39 import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
40 import jdk.internal.dynalink.support.CallSiteDescriptorFactory;
41 import jdk.nashorn.api.scripting.JSObject;
42 import jdk.nashorn.internal.lookup.MethodHandleFactory;
43 import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
44 import jdk.nashorn.internal.runtime.JSType;
45
46 /**
47 * A Dynalink linker to handle web browser built-in JS (DOM etc.) objects as well
48 * as ScriptObjects from other Nashorn contexts.
49 */
50 final class JSObjectLinker implements TypeBasedGuardingDynamicLinker, GuardingTypeConverterFactory {
51 @Override
52 public boolean canLinkType(final Class<?> type) {
53 return canLinkTypeStatic(type);
54 }
55
56 static boolean canLinkTypeStatic(final Class<?> type) {
57 // can link JSObject
58 return JSObject.class.isAssignableFrom(type);
59 }
60
61 @Override
62 public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
63 final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
64 final Object self = requestWithoutContext.getReceiver();
65 final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();
66
67 if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
68 // We only support standard "dyn:*[:*]" operations
69 return null;
70 }
71
72 final GuardedInvocation inv;
73 if (self instanceof JSObject) {
74 inv = lookup(desc);
75 } else {
76 throw new AssertionError(); // Should never reach here.
77 }
78
79 return Bootstrap.asType(inv, linkerServices, desc);
80 }
81
82 @Override
83 public GuardedTypeConversion convertToType(final Class<?> sourceType, final Class<?> targetType) throws Exception {
84 final boolean sourceIsAlwaysJSObject = JSObject.class.isAssignableFrom(sourceType);
85 if(!sourceIsAlwaysJSObject && !sourceType.isAssignableFrom(JSObject.class)) {
86 return null;
87 }
88
89 final MethodHandle converter = CONVERTERS.get(targetType);
90 if(converter == null) {
91 return null;
92 }
93
94 return new GuardedTypeConversion(new GuardedInvocation(converter, sourceIsAlwaysJSObject ? null : IS_JSOBJECT_GUARD).asType(MethodType.methodType(targetType, sourceType)), true);
95 }
96
97
98 private static GuardedInvocation lookup(final CallSiteDescriptor desc) {
99 final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
100 final int c = desc.getNameTokenCount();
101 switch (operator) {
102 case "getProp":
103 case "getElem":
104 case "getMethod":
105 return c > 2 ? findGetMethod(desc) : findGetIndexMethod();
106 case "setProp":
107 case "setElem":
108 return c > 2 ? findSetMethod(desc) : findSetIndexMethod();
109 case "call":
110 return findCallMethod(desc);
111 case "new":
112 return findNewMethod(desc);
113 default:
114 return null;
115 }
116 }
117
118 private static GuardedInvocation findGetMethod(final CallSiteDescriptor desc) {
119 final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, desc.getNameToken(2));
120 return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
121 }
122
123 private static GuardedInvocation findGetIndexMethod() {
124 return new GuardedInvocation(JSOBJECTLINKER_GET, null, IS_JSOBJECT_GUARD);
125 }
126
127 private static GuardedInvocation findSetMethod(final CallSiteDescriptor desc) {
128 final MethodHandle getter = MH.insertArguments(JSOBJECT_SETMEMBER, 1, desc.getNameToken(2));
129 return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
130 }
131
132 private static GuardedInvocation findSetIndexMethod() {
133 return new GuardedInvocation(JSOBJECTLINKER_PUT, null, IS_JSOBJECT_GUARD);
134 }
135
136 private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc) {
137 final MethodHandle func = MH.asCollector(JSOBJECT_CALL, Object[].class, desc.getMethodType().parameterCount() - 2);
138 return new GuardedInvocation(func, null, IS_JSOBJECT_GUARD);
139 }
140
141 private static GuardedInvocation findNewMethod(final CallSiteDescriptor desc) {
142 final MethodHandle func = MH.asCollector(JSOBJECT_NEW, Object[].class, desc.getMethodType().parameterCount() - 1);
143 return new GuardedInvocation(func, null, IS_JSOBJECT_GUARD);
144 }
145
146 @SuppressWarnings("unused")
147 private static boolean isJSObject(final Object self) {
148 return self instanceof JSObject;
149 }
150
151 @SuppressWarnings("unused")
152 private static Object get(final Object jsobj, final Object key) {
153 if (key instanceof Integer) {
154 return ((JSObject)jsobj).getSlot((Integer)key);
155 } else if (key instanceof Number) {
156 final int index = getIndex((Number)key);
157 if (index > -1) {
158 return ((JSObject)jsobj).getSlot(index);
159 }
160 } else if (key instanceof String) {
161 return ((JSObject)jsobj).getMember((String)key);
162 }
163 return null;
164 }
165
166 @SuppressWarnings("unused")
167 private static void put(final Object jsobj, final Object key, final Object value) {
168 if (key instanceof Integer) {
169 ((JSObject)jsobj).setSlot((Integer)key, value);
170 } else if (key instanceof Number) {
171 ((JSObject)jsobj).setSlot(getIndex((Number)key), value);
172 } else if (key instanceof String) {
173 ((JSObject)jsobj).setMember((String)key, value);
174 }
175 }
176
177 @SuppressWarnings("unused")
178 private static int toInt32(final JSObject obj) {
179 return JSType.toInt32(toNumber(obj));
180 }
181
182 @SuppressWarnings("unused")
183 private static long toInt64(final JSObject obj) {
184 return JSType.toInt64(toNumber(obj));
185 }
186
187 private static double toNumber(final JSObject obj) {
188 return obj == null ? 0 : obj.toNumber();
189 }
190
191 @SuppressWarnings("unused")
192 private static boolean toBoolean(final JSObject obj) {
193 return obj != null;
194 }
195
196 private static int getIndex(final Number n) {
197 final double value = n.doubleValue();
198 return JSType.isRepresentableAsInt(value) ? (int)value : -1;
199 }
200
201 private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
202
203 // method handles of the current class
204 private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH("isJSObject", boolean.class, Object.class);
205 private static final MethodHandle JSOBJECTLINKER_GET = findOwnMH("get", Object.class, Object.class, Object.class);
206 private static final MethodHandle JSOBJECTLINKER_PUT = findOwnMH("put", Void.TYPE, Object.class, Object.class, Object.class);
207
208 // method handles of JSObject class
209 private static final MethodHandle JSOBJECT_GETMEMBER = findJSObjectMH("getMember", Object.class, String.class);
210 private static final MethodHandle JSOBJECT_SETMEMBER = findJSObjectMH("setMember", Void.TYPE, String.class, Object.class);
211 private static final MethodHandle JSOBJECT_CALL = findJSObjectMH("call", Object.class, Object.class, Object[].class);
212 private static final MethodHandle JSOBJECT_NEW = findJSObjectMH("newObject", Object.class, Object[].class);
213
214 private static final Map<Class<?>, MethodHandle> CONVERTERS = new HashMap<>();
215 static {
216 CONVERTERS.put(boolean.class, findOwnMH("toBoolean", boolean.class, JSObject.class));
217 CONVERTERS.put(int.class, findOwnMH("toInt32", int.class, JSObject.class));
218 CONVERTERS.put(long.class, findOwnMH("toInt64", long.class, JSObject.class));
219 CONVERTERS.put(double.class, findOwnMH("toNumber", double.class, JSObject.class));
220 }
221
222 private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) {
223 return findMH(name, JSObjectLinker.class, rtype, types);
224 }
225
226 private static MethodHandle findJSObjectMH(final String name, final Class<?> rtype, final Class<?>... types) {
227 return findMH(name, JSObject.class, rtype, types);
228 }
229
230 private static MethodHandle findMH(final String name, final Class<?> target, final Class<?> rtype, final Class<?>... types) {
231 final MethodType mt = MH.type(rtype, types);
232 try {
233 return MH.findStatic(MethodHandles.lookup(), target, name, mt);
234 } catch (final MethodHandleFactory.LookupException e) {
235 return MH.findVirtual(MethodHandles.lookup(), target, name, mt);
236 }
237 }
238 }