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 javax.script.Bindings;
34 import jdk.internal.dynalink.CallSiteDescriptor;
35 import jdk.internal.dynalink.linker.GuardedInvocation;
36 import jdk.internal.dynalink.linker.GuardedTypeConversion;
37 import jdk.internal.dynalink.linker.GuardingTypeConverterFactory;
38 import jdk.internal.dynalink.linker.LinkRequest;
39 import jdk.internal.dynalink.linker.LinkerServices;
40 import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
41 import jdk.internal.dynalink.support.CallSiteDescriptorFactory;
42 import jdk.nashorn.api.scripting.JSObject;
43 import jdk.nashorn.internal.lookup.MethodHandleFactory;
44 import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
45 import jdk.nashorn.internal.runtime.JSType;
46
47 /**
48 * A Dynalink linker to handle web browser built-in JS (DOM etc.) objects as well
49 * as ScriptObjects from other Nashorn contexts.
50 */
51 final class JSObjectLinker implements TypeBasedGuardingDynamicLinker, GuardingTypeConverterFactory {
52 private final NashornBeansLinker nashornBeansLinker;
53
54 JSObjectLinker(final NashornBeansLinker nashornBeansLinker) {
55 this.nashornBeansLinker = nashornBeansLinker;
56 }
57
58 @Override
59 public boolean canLinkType(final Class<?> type) {
60 return canLinkTypeStatic(type);
61 }
62
63 static boolean canLinkTypeStatic(final Class<?> type) {
64 // can link JSObject also handles Map, Bindings to make
65 // sure those are not JSObjects.
66 return Map.class.isAssignableFrom(type) ||
67 Bindings.class.isAssignableFrom(type) ||
68 JSObject.class.isAssignableFrom(type);
69 }
70
71 @Override
72 public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
73 final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
74 final Object self = requestWithoutContext.getReceiver();
75 final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();
76
77 if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
78 // We only support standard "dyn:*[:*]" operations
79 return null;
80 }
81
82 final GuardedInvocation inv;
83 if (self instanceof JSObject) {
84 inv = lookup(desc);
85 } else if (self instanceof Map || self instanceof Bindings) {
86 // guard to make sure the Map or Bindings does not turn into JSObject later!
87 final GuardedInvocation beanInv = nashornBeansLinker.getGuardedInvocation(request, linkerServices);
88 inv = new GuardedInvocation(beanInv.getInvocation(),
89 NashornGuards.combineGuards(beanInv.getGuard(), NashornGuards.getNotJSObjectGuard()));
90 } else {
91 throw new AssertionError(); // Should never reach here.
92 }
93
94 return Bootstrap.asType(inv, linkerServices, desc);
95 }
96
97 @Override
98 public GuardedTypeConversion convertToType(final Class<?> sourceType, final Class<?> targetType) throws Exception {
99 final boolean sourceIsAlwaysJSObject = JSObject.class.isAssignableFrom(sourceType);
100 if(!sourceIsAlwaysJSObject && !sourceType.isAssignableFrom(JSObject.class)) {
101 return null;
102 }
103
104 final MethodHandle converter = CONVERTERS.get(targetType);
105 if(converter == null) {
106 return null;
107 }
108
109 return new GuardedTypeConversion(new GuardedInvocation(converter, sourceIsAlwaysJSObject ? null : IS_JSOBJECT_GUARD).asType(MethodType.methodType(targetType, sourceType)), true);
110 }
111
112
113 private static GuardedInvocation lookup(final CallSiteDescriptor desc) {
114 final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
115 final int c = desc.getNameTokenCount();
116 switch (operator) {
117 case "getProp":
118 case "getElem":
119 case "getMethod":
120 return c > 2 ? findGetMethod(desc) : findGetIndexMethod();
121 case "setProp":
122 case "setElem":
123 return c > 2 ? findSetMethod(desc) : findSetIndexMethod();
124 case "call":
125 return findCallMethod(desc);
126 case "new":
127 return findNewMethod(desc);
128 default:
129 return null;
130 }
131 }
132
133 private static GuardedInvocation findGetMethod(final CallSiteDescriptor desc) {
134 final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, desc.getNameToken(2));
135 return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
136 }
137
138 private static GuardedInvocation findGetIndexMethod() {
139 return new GuardedInvocation(JSOBJECTLINKER_GET, null, IS_JSOBJECT_GUARD);
140 }
141
142 private static GuardedInvocation findSetMethod(final CallSiteDescriptor desc) {
143 final MethodHandle getter = MH.insertArguments(JSOBJECT_SETMEMBER, 1, desc.getNameToken(2));
144 return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
145 }
146
147 private static GuardedInvocation findSetIndexMethod() {
148 return new GuardedInvocation(JSOBJECTLINKER_PUT, null, IS_JSOBJECT_GUARD);
149 }
150
151 private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc) {
152 final MethodHandle func = MH.asCollector(JSOBJECT_CALL, Object[].class, desc.getMethodType().parameterCount() - 2);
153 return new GuardedInvocation(func, null, IS_JSOBJECT_GUARD);
154 }
155
156 private static GuardedInvocation findNewMethod(final CallSiteDescriptor desc) {
157 final MethodHandle func = MH.asCollector(JSOBJECT_NEW, Object[].class, desc.getMethodType().parameterCount() - 1);
158 return new GuardedInvocation(func, null, IS_JSOBJECT_GUARD);
159 }
160
161 @SuppressWarnings("unused")
162 private static boolean isJSObject(final Object self) {
163 return self instanceof JSObject;
164 }
165
166 @SuppressWarnings("unused")
167 private static Object get(final Object jsobj, final Object key) {
168 if (key instanceof Integer) {
169 return ((JSObject)jsobj).getSlot((Integer)key);
170 } else if (key instanceof Number) {
171 final int index = getIndex((Number)key);
172 if (index > -1) {
173 return ((JSObject)jsobj).getSlot(index);
174 }
175 } else if (key instanceof String) {
176 return ((JSObject)jsobj).getMember((String)key);
177 }
178 return null;
179 }
180
181 @SuppressWarnings("unused")
182 private static void put(final Object jsobj, final Object key, final Object value) {
183 if (key instanceof Integer) {
184 ((JSObject)jsobj).setSlot((Integer)key, value);
185 } else if (key instanceof Number) {
186 ((JSObject)jsobj).setSlot(getIndex((Number)key), value);
187 } else if (key instanceof String) {
188 ((JSObject)jsobj).setMember((String)key, value);
189 }
190 }
191
192 @SuppressWarnings("unused")
193 private static int toInt32(final JSObject obj) {
194 return JSType.toInt32(toNumber(obj));
195 }
196
197 @SuppressWarnings("unused")
198 private static long toInt64(final JSObject obj) {
199 return JSType.toInt64(toNumber(obj));
200 }
201
202 private static double toNumber(final JSObject obj) {
203 return obj == null ? 0 : obj.toNumber();
204 }
205
206 @SuppressWarnings("unused")
207 private static boolean toBoolean(final JSObject obj) {
208 return obj != null;
209 }
210
211 private static int getIndex(final Number n) {
212 final double value = n.doubleValue();
213 return JSType.isRepresentableAsInt(value) ? (int)value : -1;
214 }
215
216 private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
217
218 // method handles of the current class
219 private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH("isJSObject", boolean.class, Object.class);
220 private static final MethodHandle JSOBJECTLINKER_GET = findOwnMH("get", Object.class, Object.class, Object.class);
221 private static final MethodHandle JSOBJECTLINKER_PUT = findOwnMH("put", Void.TYPE, Object.class, Object.class, Object.class);
222
223 // method handles of JSObject class
224 private static final MethodHandle JSOBJECT_GETMEMBER = findJSObjectMH("getMember", Object.class, String.class);
225 private static final MethodHandle JSOBJECT_SETMEMBER = findJSObjectMH("setMember", Void.TYPE, String.class, Object.class);
226 private static final MethodHandle JSOBJECT_CALL = findJSObjectMH("call", Object.class, Object.class, Object[].class);
227 private static final MethodHandle JSOBJECT_NEW = findJSObjectMH("newObject", Object.class, Object[].class);
228
229 private static final Map<Class<?>, MethodHandle> CONVERTERS = new HashMap<>();
230 static {
231 CONVERTERS.put(boolean.class, findOwnMH("toBoolean", boolean.class, JSObject.class));
232 CONVERTERS.put(int.class, findOwnMH("toInt32", int.class, JSObject.class));
233 CONVERTERS.put(long.class, findOwnMH("toInt64", long.class, JSObject.class));
234 CONVERTERS.put(double.class, findOwnMH("toNumber", double.class, JSObject.class));
235 }
236
237 private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) {
238 return findMH(name, JSObjectLinker.class, rtype, types);
239 }
240
241 private static MethodHandle findJSObjectMH(final String name, final Class<?> rtype, final Class<?>... types) {
242 return findMH(name, JSObject.class, rtype, types);
243 }
244
245 private static MethodHandle findMH(final String name, final Class<?> target, final Class<?> rtype, final Class<?>... types) {
246 final MethodType mt = MH.type(rtype, types);
247 try {
248 return MH.findStatic(MethodHandles.lookup(), target, name, mt);
249 } catch (final MethodHandleFactory.LookupException e) {
250 return MH.findVirtual(MethodHandles.lookup(), target, name, mt);
251 }
252 }
253 }