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.ScriptRuntime.UNDEFINED;
31
32 import java.lang.invoke.MethodHandle;
33 import java.lang.invoke.MethodHandles;
34 import java.lang.invoke.MethodType;
35 import java.util.HashMap;
36 import java.util.Map;
37 import java.util.function.Supplier;
38 import jdk.dynalink.CallSiteDescriptor;
39 import jdk.dynalink.NamedOperation;
40 import jdk.dynalink.Operation;
41 import jdk.dynalink.beans.BeansLinker;
42 import jdk.dynalink.beans.StaticClass;
43 import jdk.dynalink.linker.GuardedInvocation;
44 import jdk.dynalink.linker.GuardingDynamicLinker;
45 import jdk.dynalink.linker.GuardingTypeConverterFactory;
46 import jdk.dynalink.linker.LinkRequest;
47 import jdk.dynalink.linker.LinkerServices;
48 import jdk.dynalink.linker.support.Guards;
49 import jdk.dynalink.linker.support.Lookup;
50 import jdk.nashorn.internal.codegen.types.Type;
51 import jdk.nashorn.internal.runtime.ECMAException;
52 import jdk.nashorn.internal.runtime.JSType;
53 import jdk.nashorn.internal.runtime.ScriptRuntime;
54 import jdk.nashorn.internal.runtime.UnwarrantedOptimismException;
55
56 /**
57 * Nashorn bottom linker; used as a last-resort catch-all linker for all linking requests that fall through all other
58 * linkers (see how {@link Bootstrap} class configures the dynamic linker in its static initializer). It will throw
59 * appropriate ECMAScript errors for attempts to invoke operations on {@code null}, link no-op property getters and
60 * setters for Java objects that couldn't be linked by any other linker, and throw appropriate ECMAScript errors for
61 * attempts to invoke arbitrary Java objects as functions or constructors.
62 */
63 final class NashornBottomLinker implements GuardingDynamicLinker, GuardingTypeConverterFactory {
64
65 @Override
66 public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices)
67 throws Exception {
68 final Object self = linkRequest.getReceiver();
69
70 if (self == null) {
71 return linkNull(linkRequest);
72 }
73
74 // None of the objects that can be linked by NashornLinker should ever reach here. Basically, anything below
75 // this point is a generic Java bean. Therefore, reaching here with a ScriptObject is a Nashorn bug.
76 assert isExpectedObject(self) : "Couldn't link " + linkRequest.getCallSiteDescriptor() + " for " + self.getClass().getName();
77
78 return linkBean(linkRequest);
79 }
80
81 private static final MethodHandle EMPTY_PROP_GETTER =
82 MH.dropArguments(MH.constant(Object.class, UNDEFINED), 0, Object.class);
83 private static final MethodHandle EMPTY_ELEM_GETTER =
84 MH.dropArguments(EMPTY_PROP_GETTER, 0, Object.class);
85 private static final MethodHandle EMPTY_PROP_SETTER =
86 MH.asType(EMPTY_ELEM_GETTER, EMPTY_ELEM_GETTER.type().changeReturnType(void.class));
87 private static final MethodHandle EMPTY_ELEM_SETTER =
88 MH.dropArguments(EMPTY_PROP_SETTER, 0, Object.class);
89
90 private static final MethodHandle THROW_STRICT_PROPERTY_SETTER;
91 private static final MethodHandle THROW_STRICT_PROPERTY_REMOVER;
92 private static final MethodHandle THROW_OPTIMISTIC_UNDEFINED;
93 private static final MethodHandle MISSING_PROPERTY_REMOVER;
94
95 static {
96 final Lookup lookup = new Lookup(MethodHandles.lookup());
97 THROW_STRICT_PROPERTY_SETTER = lookup.findOwnStatic("throwStrictPropertySetter", void.class, Object.class, Object.class);
98 THROW_STRICT_PROPERTY_REMOVER = lookup.findOwnStatic("throwStrictPropertyRemover", boolean.class, Object.class, Object.class);
99 THROW_OPTIMISTIC_UNDEFINED = lookup.findOwnStatic("throwOptimisticUndefined", Object.class, int.class);
100 MISSING_PROPERTY_REMOVER = lookup.findOwnStatic("missingPropertyRemover", boolean.class, Object.class, Object.class);
101 }
102
103 private static GuardedInvocation linkBean(final LinkRequest linkRequest) throws Exception {
104 final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor();
105 final Object self = linkRequest.getReceiver();
106 switch (NashornCallSiteDescriptor.getStandardOperation(desc)) {
107 case NEW:
108 if(BeansLinker.isDynamicConstructor(self)) {
109 throw typeError("no.constructor.matches.args", ScriptRuntime.safeToString(self));
110 }
111 if(BeansLinker.isDynamicMethod(self)) {
112 throw typeError("method.not.constructor", ScriptRuntime.safeToString(self));
113 }
114 throw typeError("not.a.function", NashornCallSiteDescriptor.getFunctionErrorMessage(desc, self));
115 case CALL:
116 if(BeansLinker.isDynamicConstructor(self)) {
117 throw typeError("constructor.requires.new", ScriptRuntime.safeToString(self));
118 }
119 if(BeansLinker.isDynamicMethod(self)) {
120 throw typeError("no.method.matches.args", ScriptRuntime.safeToString(self));
121 }
122 throw typeError("not.a.function", NashornCallSiteDescriptor.getFunctionErrorMessage(desc, self));
123 default:
124 // Everything else is supposed to have been already handled by Bootstrap.beansLinker
125 // delegating to linkNoSuchBeanMember
126 throw new AssertionError("unknown call type " + desc);
127 }
128 }
129
130 static MethodHandle linkMissingBeanMember(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception {
131 final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor();
132 final String operand = NashornCallSiteDescriptor.getOperand(desc);
133 final boolean strict = NashornCallSiteDescriptor.isStrict(desc);
134 switch (NashornCallSiteDescriptor.getStandardOperation(desc)) {
135 case GET:
136 if (NashornCallSiteDescriptor.isOptimistic(desc)) {
137 return adaptThrower(MethodHandles.insertArguments(THROW_OPTIMISTIC_UNDEFINED, 0, NashornCallSiteDescriptor.getProgramPoint(desc)), desc);
138 } else if (operand != null) {
139 return getInvocation(EMPTY_PROP_GETTER, linkerServices, desc);
140 }
141 return getInvocation(EMPTY_ELEM_GETTER, linkerServices, desc);
142 case SET:
143 if (strict) {
144 return adaptThrower(bindOperand(THROW_STRICT_PROPERTY_SETTER, operand), desc);
145 } else if (operand != null) {
146 return getInvocation(EMPTY_PROP_SETTER, linkerServices, desc);
147 }
148 return getInvocation(EMPTY_ELEM_SETTER, linkerServices, desc);
149 case REMOVE:
150 if (strict) {
151 return adaptThrower(bindOperand(THROW_STRICT_PROPERTY_REMOVER, operand), desc);
152 }
153 return getInvocation(bindOperand(MISSING_PROPERTY_REMOVER, operand), linkerServices, desc);
154 default:
155 throw new AssertionError("unknown call type " + desc);
156 }
157 }
158
159 private static MethodHandle bindOperand(final MethodHandle handle, final String operand) {
160 return operand == null ? handle : MethodHandles.insertArguments(handle, 1, operand);
161 }
162
163 private static MethodHandle adaptThrower(final MethodHandle handle, final CallSiteDescriptor desc) {
164 final MethodType targetType = desc.getMethodType();
165 final int paramCount = handle.type().parameterCount();
166 return MethodHandles
167 .dropArguments(handle, paramCount, targetType.parameterList().subList(paramCount, targetType.parameterCount()))
168 .asType(targetType);
169 }
170
171 @SuppressWarnings("unused")
172 private static void throwStrictPropertySetter(final Object self, final Object name) {
173 throw createTypeError(self, name, "cant.set.property");
174 }
175
176 @SuppressWarnings("unused")
177 private static boolean throwStrictPropertyRemover(final Object self, final Object name) {
178 if (isNonConfigurableProperty(self, name)) {
179 throw createTypeError(self, name, "cant.delete.property");
180 }
181 return true;
182 }
183
184 @SuppressWarnings("unused")
185 private static boolean missingPropertyRemover(final Object self, final Object name) {
186 return !isNonConfigurableProperty(self, name);
187 }
188
189 // Corresponds to ECMAScript 5.1 8.12.7 [[Delete]] point 3 check for "isConfigurable" (but negated)
190 private static boolean isNonConfigurableProperty(final Object self, final Object name) {
191 if (self instanceof StaticClass) {
192 final Class<?> clazz = ((StaticClass)self).getRepresentedClass();
193 return BeansLinker.getReadableStaticPropertyNames(clazz).contains(name) ||
194 BeansLinker.getWritableStaticPropertyNames(clazz).contains(name) ||
195 BeansLinker.getStaticMethodNames(clazz).contains(name);
196 }
197 final Class<?> clazz = self.getClass();
198 return BeansLinker.getReadableInstancePropertyNames(clazz).contains(name) ||
199 BeansLinker.getWritableInstancePropertyNames(clazz).contains(name) ||
200 BeansLinker.getInstanceMethodNames(clazz).contains(name);
201 }
202
203 private static ECMAException createTypeError(final Object self, final Object name, final String msg) {
204 return typeError(msg, String.valueOf(name), ScriptRuntime.safeToString(self));
205 }
206
207 @SuppressWarnings("unused")
208 private static Object throwOptimisticUndefined(final int programPoint) {
209 throw new UnwarrantedOptimismException(UNDEFINED, programPoint, Type.OBJECT);
210 }
211
212 @Override
213 public GuardedInvocation convertToType(final Class<?> sourceType, final Class<?> targetType, final Supplier<MethodHandles.Lookup> lookupSupplier) throws Exception {
214 final GuardedInvocation gi = convertToTypeNoCast(sourceType, targetType);
215 return gi == null ? null : gi.asType(MH.type(targetType, sourceType));
216 }
217
218 /**
219 * Main part of the implementation of {@link GuardingTypeConverterFactory#convertToType} that doesn't
220 * care about adapting the method signature; that's done by the invoking method. Returns conversion
221 * from Object to String/number/boolean (JS primitive types).
222 * @param sourceType the source type
223 * @param targetType the target type
224 * @return a guarded invocation that converts from the source type to the target type.
225 * @throws Exception if something goes wrong
226 */
227 private static GuardedInvocation convertToTypeNoCast(final Class<?> sourceType, final Class<?> targetType) throws Exception {
228 final MethodHandle mh = CONVERTERS.get(targetType);
229 if (mh != null) {
230 return new GuardedInvocation(mh);
231 }
232
233 return null;
234 }
235
236 private static MethodHandle getInvocation(final MethodHandle handle, final LinkerServices linkerServices, final CallSiteDescriptor desc) {
237 return linkerServices.asTypeLosslessReturn(handle, desc.getMethodType());
238 }
239
240 // Used solely in an assertion to figure out if the object we get here is something we in fact expect. Objects
241 // linked by NashornLinker should never reach here.
242 private static boolean isExpectedObject(final Object obj) {
243 return !(NashornLinker.canLinkTypeStatic(obj.getClass()));
244 }
245
246 private static GuardedInvocation linkNull(final LinkRequest linkRequest) {
247 final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor();
248 switch (NashornCallSiteDescriptor.getStandardOperation(desc)) {
249 case NEW:
250 case CALL:
251 throw typeError("not.a.function", "null");
252 case GET:
253 throw typeError(NashornCallSiteDescriptor.isMethodFirstOperation(desc) ? "no.such.function" : "cant.get.property", getArgument(linkRequest), "null");
254 case SET:
255 throw typeError("cant.set.property", getArgument(linkRequest), "null");
256 case REMOVE:
257 throw typeError("cant.delete.property", getArgument(linkRequest), "null");
258 default:
259 throw new AssertionError("unknown call type " + desc);
260 }
261 }
262
263 private static final Map<Class<?>, MethodHandle> CONVERTERS = new HashMap<>();
264 static {
265 CONVERTERS.put(boolean.class, JSType.TO_BOOLEAN.methodHandle());
266 CONVERTERS.put(double.class, JSType.TO_NUMBER.methodHandle());
267 CONVERTERS.put(int.class, JSType.TO_INTEGER.methodHandle());
268 CONVERTERS.put(long.class, JSType.TO_LONG.methodHandle());
269 CONVERTERS.put(String.class, JSType.TO_STRING.methodHandle());
270 }
271
272 private static String getArgument(final LinkRequest linkRequest) {
273 final Operation op = linkRequest.getCallSiteDescriptor().getOperation();
274 if (op instanceof NamedOperation) {
275 return ((NamedOperation)op).getName().toString();
276 }
277 return ScriptRuntime.safeToString(linkRequest.getArguments()[1]);
278 }
279 }