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 static jdk.nashorn.internal.lookup.Lookup.MH;
29 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
30 import static jdk.nashorn.internal.runtime.JSType.GET_UNDEFINED;
31 import static jdk.nashorn.internal.runtime.JSType.TYPE_OBJECT_INDEX;
32 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
33
34 import java.lang.invoke.MethodHandle;
35 import java.util.HashMap;
36 import java.util.Map;
37 import jdk.internal.dynalink.CallSiteDescriptor;
38 import jdk.internal.dynalink.beans.BeansLinker;
39 import jdk.internal.dynalink.linker.GuardedInvocation;
40 import jdk.internal.dynalink.linker.GuardedTypeConversion;
41 import jdk.internal.dynalink.linker.GuardingDynamicLinker;
42 import jdk.internal.dynalink.linker.GuardingTypeConverterFactory;
43 import jdk.internal.dynalink.linker.LinkRequest;
44 import jdk.internal.dynalink.linker.LinkerServices;
45 import jdk.internal.dynalink.support.Guards;
46 import jdk.nashorn.internal.codegen.types.Type;
47 import jdk.nashorn.internal.runtime.JSType;
48 import jdk.nashorn.internal.runtime.ScriptRuntime;
49 import jdk.nashorn.internal.runtime.UnwarrantedOptimismException;
50
51 /**
52 * Nashorn bottom linker; used as a last-resort catch-all linker for all linking requests that fall through all other
53 * linkers (see how {@link Bootstrap} class configures the dynamic linker in its static initializer). It will throw
54 * appropriate ECMAScript errors for attempts to invoke operations on {@code null}, link no-op property getters and
55 * setters for Java objects that couldn't be linked by any other linker, and throw appropriate ECMAScript errors for
56 * attempts to invoke arbitrary Java objects as functions or constructors.
57 */
58 final class NashornBottomLinker implements GuardingDynamicLinker, GuardingTypeConverterFactory {
59
60 @Override
61 public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices)
62 throws Exception {
63 final Object self = linkRequest.getReceiver();
64
65 if (self == null) {
66 return linkNull(linkRequest);
67 }
68
69 // None of the objects that can be linked by NashornLinker should ever reach here. Basically, anything below
70 // this point is a generic Java bean. Therefore, reaching here with a ScriptObject is a Nashorn bug.
71 assert isExpectedObject(self) : "Couldn't link " + linkRequest.getCallSiteDescriptor() + " for " + self.getClass().getName();
72
73 return linkBean(linkRequest, linkerServices);
74 }
75
76 private static final MethodHandle EMPTY_PROP_GETTER =
77 MH.dropArguments(MH.constant(Object.class, UNDEFINED), 0, Object.class);
78 private static final MethodHandle EMPTY_ELEM_GETTER =
79 MH.dropArguments(EMPTY_PROP_GETTER, 0, Object.class);
80 private static final MethodHandle EMPTY_PROP_SETTER =
81 MH.asType(EMPTY_ELEM_GETTER, EMPTY_ELEM_GETTER.type().changeReturnType(void.class));
82 private static final MethodHandle EMPTY_ELEM_SETTER =
83 MH.dropArguments(EMPTY_PROP_SETTER, 0, Object.class);
84
85 private static GuardedInvocation linkBean(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception {
86 final NashornCallSiteDescriptor desc = (NashornCallSiteDescriptor)linkRequest.getCallSiteDescriptor();
87 final Object self = linkRequest.getReceiver();
88 final String operator = desc.getFirstOperator();
89 switch (operator) {
90 case "new":
91 if(BeansLinker.isDynamicConstructor(self)) {
92 throw typeError("no.constructor.matches.args", ScriptRuntime.safeToString(self));
93 }
94 if(BeansLinker.isDynamicMethod(self)) {
95 throw typeError("method.not.constructor", ScriptRuntime.safeToString(self));
96 }
97 throw typeError("not.a.function", desc.getFunctionErrorMessage(self));
98 case "call":
99 if(BeansLinker.isDynamicConstructor(self)) {
100 throw typeError("constructor.requires.new", ScriptRuntime.safeToString(self));
101 }
102 if(BeansLinker.isDynamicMethod(self)) {
103 throw typeError("no.method.matches.args", ScriptRuntime.safeToString(self));
104 }
105 throw typeError("not.a.function", desc.getFunctionErrorMessage(self));
106 case "callMethod":
107 throw typeError("no.such.function", getArgument(linkRequest), ScriptRuntime.safeToString(self));
108 case "getMethod":
109 // evaluate to undefined, later on Undefined will take care of throwing TypeError
110 return getInvocation(MH.dropArguments(GET_UNDEFINED.get(TYPE_OBJECT_INDEX), 0, Object.class), self, linkerServices, desc);
111 case "getProp":
112 case "getElem":
113 if(NashornCallSiteDescriptor.isOptimistic(desc)) {
114 throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
115 }
116 if (desc.getOperand() != null) {
117 return getInvocation(EMPTY_PROP_GETTER, self, linkerServices, desc);
118 }
119 return getInvocation(EMPTY_ELEM_GETTER, self, linkerServices, desc);
120 case "setProp":
121 case "setElem": {
122 final boolean strict = NashornCallSiteDescriptor.isStrict(desc);
123 if (strict) {
124 throw typeError("cant.set.property", getArgument(linkRequest), ScriptRuntime.safeToString(self));
125 }
126 if (desc.getOperand() != null) {
127 return getInvocation(EMPTY_PROP_SETTER, self, linkerServices, desc);
128 }
129 return getInvocation(EMPTY_ELEM_SETTER, self, linkerServices, desc);
130 }
131 default:
132 break;
133 }
134 throw new AssertionError("unknown call type " + desc);
135 }
136
137 @Override
138 public GuardedTypeConversion convertToType(final Class<?> sourceType, final Class<?> targetType) throws Exception {
139 final GuardedInvocation gi = convertToTypeNoCast(sourceType, targetType);
140 return gi == null ? null : new GuardedTypeConversion(gi.asType(MH.type(targetType, sourceType)), true);
141 }
142
143 /**
144 * Main part of the implementation of {@link GuardingTypeConverterFactory#convertToType(Class, Class)} that doesn't
145 * care about adapting the method signature; that's done by the invoking method. Returns conversion from Object to String/number/boolean (JS primitive types).
146 * @param sourceType the source type
147 * @param targetType the target type
148 * @return a guarded invocation that converts from the source type to the target type.
149 * @throws Exception if something goes wrong
150 */
151 private static GuardedInvocation convertToTypeNoCast(final Class<?> sourceType, final Class<?> targetType) throws Exception {
152 final MethodHandle mh = CONVERTERS.get(targetType);
153 if (mh != null) {
154 return new GuardedInvocation(mh);
155 }
156
157 return null;
158 }
159
160 private static GuardedInvocation getInvocation(final MethodHandle handle, final Object self, final LinkerServices linkerServices, final CallSiteDescriptor desc) {
161 return Bootstrap.asTypeSafeReturn(new GuardedInvocation(handle, Guards.getClassGuard(self.getClass())), linkerServices, desc);
162 }
163
164 // Used solely in an assertion to figure out if the object we get here is something we in fact expect. Objects
165 // linked by NashornLinker should never reach here.
166 private static boolean isExpectedObject(final Object obj) {
167 return !(NashornLinker.canLinkTypeStatic(obj.getClass()));
168 }
169
170 private static GuardedInvocation linkNull(final LinkRequest linkRequest) {
171 final NashornCallSiteDescriptor desc = (NashornCallSiteDescriptor)linkRequest.getCallSiteDescriptor();
172 final String operator = desc.getFirstOperator();
173 switch (operator) {
174 case "new":
175 case "call":
176 throw typeError("not.a.function", "null");
177 case "callMethod":
178 case "getMethod":
179 throw typeError("no.such.function", getArgument(linkRequest), "null");
180 case "getProp":
181 case "getElem":
182 throw typeError("cant.get.property", getArgument(linkRequest), "null");
183 case "setProp":
184 case "setElem":
185 throw typeError("cant.set.property", getArgument(linkRequest), "null");
186 default:
187 break;
188 }
189 throw new AssertionError("unknown call type " + desc);
190 }
191
192 private static final Map<Class<?>, MethodHandle> CONVERTERS = new HashMap<>();
193 static {
194 CONVERTERS.put(boolean.class, JSType.TO_BOOLEAN.methodHandle());
195 CONVERTERS.put(double.class, JSType.TO_NUMBER.methodHandle());
196 CONVERTERS.put(int.class, JSType.TO_INTEGER.methodHandle());
197 CONVERTERS.put(long.class, JSType.TO_LONG.methodHandle());
198 CONVERTERS.put(String.class, JSType.TO_STRING.methodHandle());
199 }
200
201 private static String getArgument(final LinkRequest linkRequest) {
202 final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor();
203 if (desc.getNameTokenCount() > 2) {
204 return desc.getNameToken(2);
205 }
206 return ScriptRuntime.safeToString(linkRequest.getArguments()[1]);
207 }
208 }