Bootstrap.java revision 1598:30c3bcdb762c
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 26package jdk.nashorn.internal.runtime.linker; 27 28import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup; 29import static jdk.nashorn.internal.runtime.ECMAErrors.typeError; 30 31import java.lang.invoke.CallSite; 32import java.lang.invoke.ConstantCallSite; 33import java.lang.invoke.MethodHandle; 34import java.lang.invoke.MethodHandles; 35import java.lang.invoke.MethodHandles.Lookup; 36import java.lang.invoke.MethodType; 37import jdk.dynalink.CallSiteDescriptor; 38import jdk.dynalink.DynamicLinker; 39import jdk.dynalink.DynamicLinkerFactory; 40import jdk.dynalink.beans.BeansLinker; 41import jdk.dynalink.beans.StaticClass; 42import jdk.dynalink.linker.GuardedInvocation; 43import jdk.dynalink.linker.GuardingDynamicLinker; 44import jdk.dynalink.linker.LinkRequest; 45import jdk.dynalink.linker.LinkerServices; 46import jdk.dynalink.linker.MethodTypeConversionStrategy; 47import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker; 48import jdk.dynalink.linker.support.TypeUtilities; 49import jdk.nashorn.api.scripting.JSObject; 50import jdk.nashorn.internal.codegen.CompilerConstants.Call; 51import jdk.nashorn.internal.lookup.MethodHandleFactory; 52import jdk.nashorn.internal.lookup.MethodHandleFunctionality; 53import jdk.nashorn.internal.runtime.Context; 54import jdk.nashorn.internal.runtime.ECMAException; 55import jdk.nashorn.internal.runtime.JSType; 56import jdk.nashorn.internal.runtime.OptimisticReturnFilters; 57import jdk.nashorn.internal.runtime.ScriptFunction; 58import jdk.nashorn.internal.runtime.ScriptRuntime; 59 60/** 61 * This class houses bootstrap method for invokedynamic instructions generated by compiler. 62 */ 63public final class Bootstrap { 64 /** Reference to the seed boostrap function */ 65 public static final Call BOOTSTRAP = staticCallNoLookup(Bootstrap.class, "bootstrap", CallSite.class, Lookup.class, String.class, MethodType.class, int.class); 66 67 private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality(); 68 69 private static final MethodHandle VOID_TO_OBJECT = MH.constant(Object.class, ScriptRuntime.UNDEFINED); 70 71 private static final BeansLinker beansLinker = new BeansLinker(Bootstrap::createMissingMemberHandler); 72 private static final GuardingDynamicLinker[] prioritizedLinkers; 73 private static final GuardingDynamicLinker[] fallbackLinkers; 74 static { 75 final NashornBeansLinker nashornBeansLinker = new NashornBeansLinker(beansLinker); 76 prioritizedLinkers = new GuardingDynamicLinker[] { 77 new NashornLinker(), 78 new NashornPrimitiveLinker(), 79 new NashornStaticClassLinker(beansLinker), 80 new BoundCallableLinker(), 81 new JavaSuperAdapterLinker(beansLinker), 82 new JSObjectLinker(nashornBeansLinker), 83 new BrowserJSObjectLinker(nashornBeansLinker), 84 new ReflectionCheckLinker() 85 }; 86 fallbackLinkers = new GuardingDynamicLinker[] {nashornBeansLinker, new NashornBottomLinker() }; 87 } 88 89 // do not create me!! 90 private Bootstrap() { 91 } 92 93 /** 94 * Creates a Nashorn dynamic linker with the given app class loader. 95 * @param appLoader the app class loader. It will be used to discover 96 * additional language runtime linkers (if any). 97 * @param unstableRelinkThreshold the unstable relink threshold 98 * @return a newly created dynamic linker. 99 */ 100 public static DynamicLinker createDynamicLinker(final ClassLoader appLoader, 101 final int unstableRelinkThreshold) { 102 final DynamicLinkerFactory factory = new DynamicLinkerFactory(); 103 factory.setPrioritizedLinkers(prioritizedLinkers); 104 factory.setFallbackLinkers(fallbackLinkers); 105 factory.setSyncOnRelink(true); 106 factory.setPrelinkTransformer((inv, request, linkerServices) -> { 107 final CallSiteDescriptor desc = request.getCallSiteDescriptor(); 108 return OptimisticReturnFilters.filterOptimisticReturnValue(inv, desc).asType(linkerServices, desc.getMethodType()); 109 }); 110 factory.setAutoConversionStrategy(Bootstrap::unboxReturnType); 111 factory.setInternalObjectsFilter(NashornBeansLinker.createHiddenObjectFilter()); 112 factory.setUnstableRelinkThreshold(unstableRelinkThreshold); 113 114 // Linkers for any additional language runtimes deployed alongside Nashorn will be picked up by the factory. 115 factory.setClassLoader(appLoader); 116 return factory.createLinker(); 117 } 118 119 /** 120 * Returns a dynamic linker for the specific Java class using beans semantics. 121 * @param clazz the Java class 122 * @return a dynamic linker for the specific Java class using beans semantics. 123 */ 124 public static TypeBasedGuardingDynamicLinker getBeanLinkerForClass(final Class<?> clazz) { 125 return beansLinker.getLinkerForClass(clazz); 126 } 127 128 /** 129 * Returns if the given object is a "callable" 130 * @param obj object to be checked for callability 131 * @return true if the obj is callable 132 */ 133 public static boolean isCallable(final Object obj) { 134 if (obj == ScriptRuntime.UNDEFINED || obj == null) { 135 return false; 136 } 137 138 return obj instanceof ScriptFunction || 139 isJSObjectFunction(obj) || 140 BeansLinker.isDynamicMethod(obj) || 141 obj instanceof BoundCallable || 142 isFunctionalInterfaceObject(obj) || 143 obj instanceof StaticClass; 144 } 145 146 /** 147 * Returns true if the given object is a strict callable 148 * @param callable the callable object to be checked for strictness 149 * @return true if the obj is a strict callable, false if it is a non-strict callable. 150 * @throws ECMAException with {@code TypeError} if the object is not a callable. 151 */ 152 public static boolean isStrictCallable(final Object callable) { 153 if (callable instanceof ScriptFunction) { 154 return ((ScriptFunction)callable).isStrict(); 155 } else if (isJSObjectFunction(callable)) { 156 return ((JSObject)callable).isStrictFunction(); 157 } else if (callable instanceof BoundCallable) { 158 return isStrictCallable(((BoundCallable)callable).getCallable()); 159 } else if (BeansLinker.isDynamicMethod(callable) || callable instanceof StaticClass) { 160 return false; 161 } 162 throw notFunction(callable); 163 } 164 165 private static ECMAException notFunction(final Object obj) { 166 return typeError("not.a.function", ScriptRuntime.safeToString(obj)); 167 } 168 169 private static boolean isJSObjectFunction(final Object obj) { 170 return obj instanceof JSObject && ((JSObject)obj).isFunction(); 171 } 172 173 /** 174 * Returns if the given object is a dynalink Dynamic method 175 * @param obj object to be checked 176 * @return true if the obj is a dynamic method 177 */ 178 public static boolean isDynamicMethod(final Object obj) { 179 return BeansLinker.isDynamicMethod(obj instanceof BoundCallable ? ((BoundCallable)obj).getCallable() : obj); 180 } 181 182 /** 183 * Returns if the given object is an instance of an interface annotated with 184 * java.lang.FunctionalInterface 185 * @param obj object to be checked 186 * @return true if the obj is an instance of @FunctionalInterface interface 187 */ 188 public static boolean isFunctionalInterfaceObject(final Object obj) { 189 return !JSType.isPrimitive(obj) && (NashornBeansLinker.getFunctionalInterfaceMethodName(obj.getClass()) != null); 190 } 191 192 /** 193 * Create a call site and link it for Nashorn. This version of the method conforms to the invokedynamic bootstrap 194 * method expected signature and is referenced from Nashorn generated bytecode as the bootstrap method for all 195 * invokedynamic instructions. 196 * @param lookup MethodHandle lookup. Ignored as Nashorn only uses public lookup. 197 * @param opDesc Dynalink dynamic operation descriptor. 198 * @param type Method type. 199 * @param flags flags for call type, trace/profile etc. 200 * @return CallSite with MethodHandle to appropriate method or null if not found. 201 */ 202 public static CallSite bootstrap(final Lookup lookup, final String opDesc, final MethodType type, final int flags) { 203 return Context.getDynamicLinker(lookup.lookupClass()).link(LinkerCallSite.newLinkerCallSite(lookup, opDesc, type, flags)); 204 } 205 206 /** 207 * Boostrapper for math calls that may overflow 208 * @param lookup lookup 209 * @param name name of operation 210 * @param type method type 211 * @param programPoint program point to bind to callsite 212 * 213 * @return callsite for a math intrinsic node 214 */ 215 public static CallSite mathBootstrap(final Lookup lookup, final String name, final MethodType type, final int programPoint) { 216 final MethodHandle mh; 217 switch (name) { 218 case "iadd": 219 mh = JSType.ADD_EXACT.methodHandle(); 220 break; 221 case "isub": 222 mh = JSType.SUB_EXACT.methodHandle(); 223 break; 224 case "imul": 225 mh = JSType.MUL_EXACT.methodHandle(); 226 break; 227 case "idiv": 228 mh = JSType.DIV_EXACT.methodHandle(); 229 break; 230 case "irem": 231 mh = JSType.REM_EXACT.methodHandle(); 232 break; 233 case "ineg": 234 mh = JSType.NEGATE_EXACT.methodHandle(); 235 break; 236 default: 237 throw new AssertionError("unsupported math intrinsic"); 238 } 239 return new ConstantCallSite(MH.insertArguments(mh, mh.type().parameterCount() - 1, programPoint)); 240 } 241 242 /** 243 * Returns a dynamic invoker for a specified dynamic operation using the 244 * public lookup. You can use this method to create a method handle that 245 * when invoked acts completely as if it were a Nashorn-linked call site. 246 * Note that the available operations are encoded in the flags, see 247 * {@link NashornCallSiteDescriptor} operation constants. If the operation 248 * takes a name, it should be set otherwise empty name (not null) should be 249 * used. All names (including the empty one) should be encoded using 250 * {@link NameCodec#encode(String)}. Few examples: 251 * <ul> 252 * <li>Get a named property with fixed name: 253 * <pre> 254 * MethodHandle getColor = Boostrap.createDynamicInvoker( 255 * "color", 256 * NashornCallSiteDescriptor.GET_PROPERTY, 257 * Object.class, Object.class); 258 * Object obj = ...; // somehow obtain the object 259 * Object color = getColor.invokeExact(obj); 260 * </pre> 261 * </li> 262 * <li>Get a named property with variable name: 263 * <pre> 264 * MethodHandle getProperty = Boostrap.createDynamicInvoker( 265 * NameCodec.encode(""), 266 * NashornCallSiteDescriptor.GET_PROPERTY, 267 * Object.class, Object.class, String.class); 268 * Object obj = ...; // somehow obtain the object 269 * Object color = getProperty.invokeExact(obj, "color"); 270 * Object shape = getProperty.invokeExact(obj, "shape"); 271 * 272 * MethodHandle getNumProperty = Boostrap.createDynamicInvoker( 273 * NameCodec.encode(""), 274 * NashornCallSiteDescriptor.GET_ELEMENT, 275 * Object.class, Object.class, int.class); 276 * Object elem42 = getNumProperty.invokeExact(obj, 42); 277 * </pre> 278 * </li> 279 * <li>Set a named property with fixed name: 280 * <pre> 281 * MethodHandle setColor = Boostrap.createDynamicInvoker( 282 * "color", 283 * NashornCallSiteDescriptor.SET_PROPERTY, 284 * void.class, Object.class, Object.class); 285 * Object obj = ...; // somehow obtain the object 286 * setColor.invokeExact(obj, Color.BLUE); 287 * </pre> 288 * </li> 289 * <li>Set a property with variable name: 290 * <pre> 291 * MethodHandle setProperty = Boostrap.createDynamicInvoker( 292 * NameCodec.encode(""), 293 * NashornCallSiteDescriptor.SET_PROPERTY, 294 * void.class, Object.class, String.class, Object.class); 295 * Object obj = ...; // somehow obtain the object 296 * setProperty.invokeExact(obj, "color", Color.BLUE); 297 * setProperty.invokeExact(obj, "shape", Shape.CIRCLE); 298 * </pre> 299 * </li> 300 * <li>Call a function on an object; note it's a two-step process: get the 301 * method, then invoke the method. This is the actual: 302 * <pre> 303 * MethodHandle findFooFunction = Boostrap.createDynamicInvoker( 304 * "foo", 305 * NashornCallSiteDescriptor.GET_METHOD, 306 * Object.class, Object.class); 307 * Object obj = ...; // somehow obtain the object 308 * Object foo_fn = findFooFunction.invokeExact(obj); 309 * MethodHandle callFunctionWithTwoArgs = Boostrap.createDynamicCallInvoker( 310 * Object.class, Object.class, Object.class, Object.class, Object.class); 311 * // Note: "call" operation takes a function, then a "this" value, then the arguments: 312 * Object foo_retval = callFunctionWithTwoArgs.invokeExact(foo_fn, obj, arg1, arg2); 313 * </pre> 314 * </li> 315 * </ul> 316 * Few additional remarks: 317 * <ul> 318 * <li>Just as Nashorn works with any Java object, the invokers returned 319 * from this method can also be applied to arbitrary Java objects in 320 * addition to Nashorn JavaScript objects.</li> 321 * <li>For invoking a named function on an object, you can also use the 322 * {@link InvokeByName} convenience class.</li> 323 * <li>There's no rule that the variable property identifier has to be a 324 * {@code String} for {@code GET_PROPERTY/SET_PROPERTY} and {@code int} for 325 * {@code GET_ELEMENT/SET_ELEMENT}. You can declare their type to be 326 * {@code int}, {@code double}, {@code Object}, and so on regardless of the 327 * kind of the operation.</li> 328 * <li>You can be as specific in parameter types as you want. E.g. if you 329 * know that the receiver of the operation will always be 330 * {@code ScriptObject}, you can pass {@code ScriptObject.class} as its 331 * parameter type. If you happen to link to a method that expects different 332 * types, (you can use these invokers on POJOs too, after all, and end up 333 * linking with their methods that have strongly-typed signatures), all 334 * necessary conversions allowed by either Java or JavaScript will be 335 * applied: if invoked methods specify either primitive or wrapped Java 336 * numeric types, or {@code String} or {@code boolean/Boolean}, then the 337 * parameters might be subjected to standard ECMAScript {@code ToNumber}, 338 * {@code ToString}, and {@code ToBoolean} conversion, respectively. Less 339 * obviously, if the expected parameter type is a SAM type, and you pass a 340 * JavaScript function, a proxy object implementing the SAM type and 341 * delegating to the function will be passed. Linkage can often be optimized 342 * when linkers have more specific type information than "everything can be 343 * an object".</li> 344 * <li>You can also be as specific in return types as you want. For return 345 * types any necessary type conversion available in either Java or 346 * JavaScript will be automatically applied, similar to the process 347 * described for parameters, only in reverse direction: if you specify any 348 * either primitive or wrapped Java numeric type, or {@code String} or 349 * {@code boolean/Boolean}, then the return values will be subjected to 350 * standard ECMAScript {@code ToNumber}, {@code ToString}, and 351 * {@code ToBoolean} conversion, respectively. Less obviously, if the return 352 * type is a SAM type, and the return value is a JavaScript function, a 353 * proxy object implementing the SAM type and delegating to the function 354 * will be returned.</li> 355 * </ul> 356 * @param name name at the call site. Must not be null. Must be encoded 357 * using {@link NameCodec#encode(String)}. If the operation does not take a 358 * name, use empty string (also has to be encoded). 359 * @param flags the call site flags for the operation; see 360 * {@link NashornCallSiteDescriptor} for available flags. The most important 361 * part of the flags are the ones encoding the actual operation. 362 * @param rtype the return type for the operation 363 * @param ptypes the parameter types for the operation 364 * @return MethodHandle for invoking the operation. 365 */ 366 public static MethodHandle createDynamicInvoker(final String name, final int flags, final Class<?> rtype, final Class<?>... ptypes) { 367 return bootstrap(MethodHandles.publicLookup(), name, MethodType.methodType(rtype, ptypes), flags).dynamicInvoker(); 368 } 369 370 /** 371 * Returns a dynamic invoker for the {@link NashornCallSiteDescriptor#CALL} 372 * operation using the public lookup. 373 * @param rtype the return type for the operation 374 * @param ptypes the parameter types for the operation 375 * @return a dynamic invoker for the {@code CALL} operation. 376 */ 377 public static MethodHandle createDynamicCallInvoker(final Class<?> rtype, final Class<?>... ptypes) { 378 return createDynamicInvoker("", NashornCallSiteDescriptor.CALL, rtype, ptypes); 379 } 380 381 /** 382 * Returns a dynamic invoker for a specified dynamic operation using the 383 * public lookup. Similar to 384 * {@link #createDynamicInvoker(String, int, Class, Class...)} but with 385 * already precomposed method type. 386 * @param name name at the call site. 387 * @param flags flags at the call site 388 * @param type the method type for the operation 389 * @return MethodHandle for invoking the operation. 390 */ 391 public static MethodHandle createDynamicInvoker(final String name, final int flags, final MethodType type) { 392 return bootstrap(MethodHandles.publicLookup(), name, type, flags).dynamicInvoker(); 393 } 394 395 /** 396 * Binds any object Nashorn can use as a [[Callable]] to a receiver and optionally arguments. 397 * @param callable the callable to bind 398 * @param boundThis the bound "this" value. 399 * @param boundArgs the bound arguments. Can be either null or empty array to signify no arguments are bound. 400 * @return a bound callable. 401 * @throws ECMAException with {@code TypeError} if the object is not a callable. 402 */ 403 public static Object bindCallable(final Object callable, final Object boundThis, final Object[] boundArgs) { 404 if (callable instanceof ScriptFunction) { 405 return ((ScriptFunction)callable).createBound(boundThis, boundArgs); 406 } else if (callable instanceof BoundCallable) { 407 return ((BoundCallable)callable).bind(boundArgs); 408 } else if (isCallable(callable)) { 409 return new BoundCallable(callable, boundThis, boundArgs); 410 } 411 throw notFunction(callable); 412 } 413 414 /** 415 * Creates a super-adapter for an adapter, that is, an adapter to the adapter that allows invocation of superclass 416 * methods on it. 417 * @param adapter the original adapter 418 * @return a new adapter that can be used to invoke super methods on the original adapter. 419 */ 420 public static Object createSuperAdapter(final Object adapter) { 421 return new JavaSuperAdapter(adapter); 422 } 423 424 /** 425 * If the given class is a reflection-specific class (anything in {@code java.lang.reflect} and 426 * {@code java.lang.invoke} package, as well a {@link Class} and any subclass of {@link ClassLoader}) and there is 427 * a security manager in the system, then it checks the {@code nashorn.JavaReflection} {@code RuntimePermission}. 428 * @param clazz the class being tested 429 * @param isStatic is access checked for static members (or instance members) 430 */ 431 public static void checkReflectionAccess(final Class<?> clazz, final boolean isStatic) { 432 ReflectionCheckLinker.checkReflectionAccess(clazz, isStatic); 433 } 434 435 /** 436 * Returns the Nashorn's internally used dynamic linker's services object. Note that in code that is processing a 437 * linking request, you will normally use the {@code LinkerServices} object passed by whatever top-level linker 438 * invoked the linking (if the call site is in Nashorn-generated code, you'll get this object anyway). You should 439 * only resort to retrieving a linker services object using this method when you need some linker services (e.g. 440 * type converter method handles) outside of a code path that is linking a call site. 441 * @return Nashorn's internal dynamic linker's services object. 442 */ 443 public static LinkerServices getLinkerServices() { 444 return Context.getDynamicLinker().getLinkerServices(); 445 } 446 447 /** 448 * Takes a guarded invocation, and ensures its method and guard conform to the type of the call descriptor, using 449 * all type conversions allowed by the linker's services. This method is used by Nashorn's linkers as a last step 450 * before returning guarded invocations. Most of the code used to produce the guarded invocations does not make an 451 * effort to coordinate types of the methods, and so a final type adjustment before a guarded invocation is returned 452 * to the aggregating linker is the responsibility of the linkers themselves. 453 * @param inv the guarded invocation that needs to be type-converted. Can be null. 454 * @param linkerServices the linker services object providing the type conversions. 455 * @param desc the call site descriptor to whose method type the invocation needs to conform. 456 * @return the type-converted guarded invocation. If input is null, null is returned. If the input invocation 457 * already conforms to the requested type, it is returned unchanged. 458 */ 459 static GuardedInvocation asTypeSafeReturn(final GuardedInvocation inv, final LinkerServices linkerServices, final CallSiteDescriptor desc) { 460 return inv == null ? null : inv.asTypeSafeReturn(linkerServices, desc.getMethodType()); 461 } 462 463 /** 464 * Adapts the return type of the method handle with {@code explicitCastArguments} when it is an unboxing 465 * conversion. This will ensure that nulls are unwrapped to false or 0. 466 * @param target the target method handle 467 * @param newType the desired new type. Note that this method does not adapt the method handle completely to the 468 * new type, it only adapts the return type; this is allowed as per 469 * {@link DynamicLinkerFactory#setAutoConversionStrategy(MethodTypeConversionStrategy)}, which is what this method 470 * is used for. 471 * @return the method handle with adapted return type, if it required an unboxing conversion. 472 */ 473 private static MethodHandle unboxReturnType(final MethodHandle target, final MethodType newType) { 474 final MethodType targetType = target.type(); 475 final Class<?> oldReturnType = targetType.returnType(); 476 final Class<?> newReturnType = newType.returnType(); 477 if (TypeUtilities.isWrapperType(oldReturnType)) { 478 if (newReturnType.isPrimitive()) { 479 // The contract of setAutoConversionStrategy is such that the difference between newType and targetType 480 // can only be JLS method invocation conversions. 481 assert TypeUtilities.isMethodInvocationConvertible(oldReturnType, newReturnType); 482 return MethodHandles.explicitCastArguments(target, targetType.changeReturnType(newReturnType)); 483 } 484 } else if (oldReturnType == void.class && newReturnType == Object.class) { 485 return MethodHandles.filterReturnValue(target, VOID_TO_OBJECT); 486 } 487 return target; 488 } 489 490 private static MethodHandle createMissingMemberHandler( 491 final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { 492 if (BrowserJSObjectLinker.canLinkTypeStatic(linkRequest.getReceiver().getClass())) { 493 // Don't create missing member handlers for the browser JS objects as they 494 // have their own logic. 495 return null; 496 } 497 return NashornBottomLinker.linkMissingBeanMember(linkRequest, linkerServices); 498 } 499} 500