1 /*
2 * Copyright (c) 2014, 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 static jdk.nashorn.internal.runtime.JSType.isString;
29 import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_CALL;
30 import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_GETMEMBER;
31 import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_GETSLOT;
32 import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_SETMEMBER;
33 import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_SETSLOT;
34
35 import java.lang.invoke.MethodHandle;
36 import java.lang.invoke.MethodHandles;
37 import jdk.dynalink.CallSiteDescriptor;
38 import jdk.dynalink.linker.GuardedInvocation;
39 import jdk.dynalink.linker.LinkRequest;
40 import jdk.dynalink.linker.LinkerServices;
41 import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker;
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.
48 */
49 final class BrowserJSObjectLinker implements TypeBasedGuardingDynamicLinker {
50 private static final String JSOBJECT_CLASS = "netscape.javascript.JSObject";
51 private static final Class<?> jsObjectClass = findBrowserJSObjectClass();
52 private final NashornBeansLinker nashornBeansLinker;
53
54 BrowserJSObjectLinker(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 return jsObjectClass != null && jsObjectClass.isAssignableFrom(type);
65 }
66
67 private static void checkJSObjectClass() {
68 assert jsObjectClass != null : JSOBJECT_CLASS + " not found!";
69 }
70
71 @Override
72 public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
73 final Object self = request.getReceiver();
74 final CallSiteDescriptor desc = request.getCallSiteDescriptor();
75 checkJSObjectClass();
76
77 assert jsObjectClass.isInstance(self);
78
79 GuardedInvocation inv = lookup(desc, request, linkerServices);
80 inv = inv.replaceMethods(linkerServices.filterInternalObjects(inv.getInvocation()), inv.getGuard());
81
82 return Bootstrap.asTypeSafeReturn(inv, linkerServices, desc);
83 }
84
85 private GuardedInvocation lookup(final CallSiteDescriptor desc, final LinkRequest request, final LinkerServices linkerServices) throws Exception {
86 GuardedInvocation inv;
87 try {
88 inv = nashornBeansLinker.getGuardedInvocation(request, linkerServices);
89 } catch (final Throwable th) {
90 inv = null;
91 }
92
93 final String name = NashornCallSiteDescriptor.getOperand(desc);
94 switch (NashornCallSiteDescriptor.getStandardOperation(desc)) {
95 case GET:
96 return name != null ? findGetMethod(name, inv) : findGetIndexMethod(inv);
97 case SET:
98 return name != null ? findSetMethod(name, inv) : findSetIndexMethod();
99 case CALL:
100 return findCallMethod(desc);
101 default:
102 return null;
103 }
104 }
105
106 private static GuardedInvocation findGetMethod(final String name, final GuardedInvocation inv) {
107 if (inv != null) {
108 return inv;
109 }
110 final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, name);
111 return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
112 }
113
114 private static GuardedInvocation findGetIndexMethod(final GuardedInvocation inv) {
115 final MethodHandle getter = MH.insertArguments(JSOBJECTLINKER_GET, 0, inv.getInvocation());
116 return inv.replaceMethods(getter, inv.getGuard());
117 }
118
119 private static GuardedInvocation findSetMethod(final String name, final GuardedInvocation inv) {
120 if (inv != null) {
121 return inv;
122 }
123 final MethodHandle getter = MH.insertArguments(JSOBJECT_SETMEMBER, 1, name);
124 return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
125 }
126
127 private static GuardedInvocation findSetIndexMethod() {
128 return new GuardedInvocation(JSOBJECTLINKER_PUT, IS_JSOBJECT_GUARD);
129 }
130
131 private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc) {
132 final MethodHandle call = MH.insertArguments(JSOBJECT_CALL, 1, "call");
133 return new GuardedInvocation(MH.asCollector(call, Object[].class, desc.getMethodType().parameterCount() - 1), IS_JSOBJECT_GUARD);
134 }
135
136 @SuppressWarnings("unused")
137 private static boolean isJSObject(final Object self) {
138 return jsObjectClass.isInstance(self);
139 }
140
141 @SuppressWarnings("unused")
142 private static Object get(final MethodHandle fallback, final Object jsobj, final Object key) throws Throwable {
143 if (key instanceof Integer) {
144 return JSOBJECT_GETSLOT.invokeExact(jsobj, (int)key);
145 } else if (key instanceof Number) {
146 final int index = getIndex((Number)key);
147 if (index > -1) {
148 return JSOBJECT_GETSLOT.invokeExact(jsobj, index);
149 }
150 } else if (isString(key)) {
151 final String name = key.toString();
152 if (name.indexOf('(') != -1) {
153 return fallback.invokeExact(jsobj, (Object) name);
154 }
155 return JSOBJECT_GETMEMBER.invokeExact(jsobj, name);
156 }
157 return null;
158 }
159
160 @SuppressWarnings("unused")
161 private static void put(final Object jsobj, final Object key, final Object value) throws Throwable {
162 if (key instanceof Integer) {
163 JSOBJECT_SETSLOT.invokeExact(jsobj, (int)key, value);
164 } else if (key instanceof Number) {
165 JSOBJECT_SETSLOT.invokeExact(jsobj, getIndex((Number)key), value);
166 } else if (isString(key)) {
167 JSOBJECT_SETMEMBER.invokeExact(jsobj, key.toString(), value);
168 }
169 }
170
171 private static int getIndex(final Number n) {
172 final double value = n.doubleValue();
173 return JSType.isRepresentableAsInt(value) ? (int)value : -1;
174 }
175
176 private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
177 // method handles of the current class
178 private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH_S("isJSObject", boolean.class, Object.class);
179 private static final MethodHandle JSOBJECTLINKER_GET = findOwnMH_S("get", Object.class, MethodHandle.class, Object.class, Object.class);
180 private static final MethodHandle JSOBJECTLINKER_PUT = findOwnMH_S("put", Void.TYPE, Object.class, Object.class, Object.class);
181
182 private static MethodHandle findOwnMH_S(final String name, final Class<?> rtype, final Class<?>... types) {
183 return MH.findStatic(MethodHandles.lookup(), BrowserJSObjectLinker.class, name, MH.type(rtype, types));
184 }
185
186 // method handles of netscape.javascript.JSObject class
187 // These are in separate class as we lazily initialize these
188 // method handles when we hit a subclass of JSObject first time.
189 static class JSObjectHandles {
190 // method handles of JSObject class
191 static final MethodHandle JSOBJECT_GETMEMBER = findJSObjectMH_V("getMember", Object.class, String.class).asType(MH.type(Object.class, Object.class, String.class));
192 static final MethodHandle JSOBJECT_GETSLOT = findJSObjectMH_V("getSlot", Object.class, int.class).asType(MH.type(Object.class, Object.class, int.class));
193 static final MethodHandle JSOBJECT_SETMEMBER = findJSObjectMH_V("setMember", Void.TYPE, String.class, Object.class).asType(MH.type(Void.TYPE, Object.class, String.class, Object.class));
194 static final MethodHandle JSOBJECT_SETSLOT = findJSObjectMH_V("setSlot", Void.TYPE, int.class, Object.class).asType(MH.type(Void.TYPE, Object.class, int.class, Object.class));
195 static final MethodHandle JSOBJECT_CALL = findJSObjectMH_V("call", Object.class, String.class, Object[].class).asType(MH.type(Object.class, Object.class, String.class, Object[].class));
196
197 private static MethodHandle findJSObjectMH_V(final String name, final Class<?> rtype, final Class<?>... types) {
198 checkJSObjectClass();
199 return MH.findVirtual(MethodHandles.publicLookup(), jsObjectClass, name, MH.type(rtype, types));
200 }
201 }
202
203 private static Class<?> findBrowserJSObjectClass() {
204 ClassLoader extLoader;
205 extLoader = BrowserJSObjectLinker.class.getClassLoader();
206 // in case nashorn is loaded as bootstrap!
207 if (extLoader == null) {
208 extLoader = ClassLoader.getSystemClassLoader().getParent();
209 }
210 try {
211 return Class.forName(JSOBJECT_CLASS, false, extLoader);
212 } catch (final ClassNotFoundException e) {
213 return null;
214 }
215 }
216 }