1 /* 2 * Copyright (c) 2017, 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 java.lang.invoke; 27 28 import jdk.internal.loader.BootLoader; 29 import jdk.internal.org.objectweb.asm.ClassWriter; 30 import jdk.internal.org.objectweb.asm.FieldVisitor; 31 import jdk.internal.org.objectweb.asm.MethodVisitor; 32 import jdk.internal.vm.annotation.Stable; 33 import sun.invoke.util.BytecodeName; 34 35 import java.lang.reflect.Constructor; 36 import java.lang.reflect.Field; 37 import java.lang.reflect.Modifier; 38 import java.security.AccessController; 39 import java.security.PrivilegedAction; 40 import java.security.ProtectionDomain; 41 import java.util.ArrayList; 42 import java.util.Collections; 43 import java.util.List; 44 import java.util.Objects; 45 import java.util.concurrent.ConcurrentHashMap; 46 import java.util.function.Function; 47 48 import static java.lang.invoke.LambdaForm.*; 49 import static java.lang.invoke.MethodHandleNatives.Constants.REF_getStatic; 50 import static java.lang.invoke.MethodHandleNatives.Constants.REF_putStatic; 51 import static java.lang.invoke.MethodHandleStatics.*; 52 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP; 53 import static jdk.internal.org.objectweb.asm.Opcodes.*; 54 55 /** 56 * Class specialization code. 57 * @param <T> top class under which species classes are created. 58 * @param <K> key which identifies individual specializations. 59 * @param <S> species data type. 60 */ 61 /*non-public*/ 62 abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesData> { 63 private final Class<T> topClass; 64 private final Class<K> keyType; 65 private final Class<S> metaType; 66 private final MemberName sdAccessor; 67 private final String sdFieldName; 68 private final List<MemberName> transformMethods; 69 private final MethodType baseConstructorType; 70 private final S topSpecies; 71 private final ConcurrentHashMap<K, Object> cache = new ConcurrentHashMap<>(); 72 private final Factory factory; 73 private @Stable boolean topClassIsSuper; 74 75 /** Return the top type mirror, for type {@code T} */ topClass()76 public final Class<T> topClass() { return topClass; } 77 78 /** Return the key type mirror, for type {@code K} */ keyType()79 public final Class<K> keyType() { return keyType; } 80 81 /** Return the species metadata type mirror, for type {@code S} */ metaType()82 public final Class<S> metaType() { return metaType; } 83 84 /** Report the leading arguments (if any) required by every species factory. 85 * Every species factory adds its own field types as additional arguments, 86 * but these arguments always come first, in every factory method. 87 */ baseConstructorType()88 protected MethodType baseConstructorType() { return baseConstructorType; } 89 90 /** Return the trivial species for the null sequence of arguments. */ topSpecies()91 protected final S topSpecies() { return topSpecies; } 92 93 /** Return the list of transform methods originally given at creation of this specializer. */ transformMethods()94 protected final List<MemberName> transformMethods() { return transformMethods; } 95 96 /** Return the factory object used to build and load concrete species code. */ factory()97 protected final Factory factory() { return factory; } 98 99 /** 100 * Constructor for this class specializer. 101 * @param topClass type mirror for T 102 * @param keyType type mirror for K 103 * @param metaType type mirror for S 104 * @param baseConstructorType principal constructor type 105 * @param sdAccessor the method used to get the speciesData 106 * @param sdFieldName the name of the species data field, inject the speciesData object 107 * @param transformMethods optional list of transformMethods 108 */ ClassSpecializer(Class<T> topClass, Class<K> keyType, Class<S> metaType, MethodType baseConstructorType, MemberName sdAccessor, String sdFieldName, List<MemberName> transformMethods)109 protected ClassSpecializer(Class<T> topClass, 110 Class<K> keyType, 111 Class<S> metaType, 112 MethodType baseConstructorType, 113 MemberName sdAccessor, 114 String sdFieldName, 115 List<MemberName> transformMethods) { 116 this.topClass = topClass; 117 this.keyType = keyType; 118 this.metaType = metaType; 119 this.sdAccessor = sdAccessor; 120 this.transformMethods = List.copyOf(transformMethods); 121 this.sdFieldName = sdFieldName; 122 this.baseConstructorType = baseConstructorType.changeReturnType(void.class); 123 this.factory = makeFactory(); 124 K tsk = topSpeciesKey(); 125 S topSpecies = null; 126 if (tsk != null && topSpecies == null) { 127 // if there is a key, build the top species if needed: 128 topSpecies = findSpecies(tsk); 129 } 130 this.topSpecies = topSpecies; 131 } 132 133 // Utilities for subclass constructors: reflectConstructor(Class<T> defc, Class<?>... ptypes)134 protected static <T> Constructor<T> reflectConstructor(Class<T> defc, Class<?>... ptypes) { 135 try { 136 return defc.getDeclaredConstructor(ptypes); 137 } catch (NoSuchMethodException ex) { 138 throw newIAE(defc.getName()+"("+MethodType.methodType(void.class, ptypes)+")", ex); 139 } 140 } 141 reflectField(Class<?> defc, String name)142 protected static Field reflectField(Class<?> defc, String name) { 143 try { 144 return defc.getDeclaredField(name); 145 } catch (NoSuchFieldException ex) { 146 throw newIAE(defc.getName()+"."+name, ex); 147 } 148 } 149 newIAE(String message, Throwable cause)150 private static RuntimeException newIAE(String message, Throwable cause) { 151 return new IllegalArgumentException(message, cause); 152 } 153 154 private static final Function<Object, Object> CREATE_RESERVATION = new Function<>() { 155 @Override 156 public Object apply(Object key) { 157 return new Object(); 158 } 159 }; 160 findSpecies(K key)161 public final S findSpecies(K key) { 162 // Note: Species instantiation may throw VirtualMachineError because of 163 // code cache overflow. If this happens the species bytecode may be 164 // loaded but not linked to its species metadata (with MH's etc). 165 // That will cause a throw out of Factory.loadSpecies. 166 // 167 // In a later attempt to get the same species, the already-loaded 168 // class will be present in the system dictionary, causing an 169 // error when the species generator tries to reload it. 170 // We try to detect this case and link the pre-existing code. 171 // 172 // Although it would be better to start fresh by loading a new 173 // copy, we have to salvage the previously loaded but broken code. 174 // (As an alternative, we might spin a new class with a new name, 175 // or use the anonymous class mechanism.) 176 // 177 // In the end, as long as everybody goes through this findSpecies method, 178 // it will ensure only one SpeciesData will be set successfully on a 179 // concrete class if ever. 180 // The concrete class is published via SpeciesData instance 181 // returned here only after the class and species data are linked together. 182 Object speciesDataOrReservation = cache.computeIfAbsent(key, CREATE_RESERVATION); 183 // Separating the creation of a placeholder SpeciesData instance above 184 // from the loading and linking a real one below ensures we can never 185 // accidentally call computeIfAbsent recursively. 186 S speciesData; 187 if (speciesDataOrReservation.getClass() == Object.class) { 188 synchronized (speciesDataOrReservation) { 189 Object existingSpeciesData = cache.get(key); 190 if (existingSpeciesData == speciesDataOrReservation) { // won the race 191 // create a new SpeciesData... 192 speciesData = newSpeciesData(key); 193 // load and link it... 194 speciesData = factory.loadSpecies(speciesData); 195 if (!cache.replace(key, existingSpeciesData, speciesData)) { 196 throw newInternalError("Concurrent loadSpecies"); 197 } 198 } else { // lost the race; the retrieved existingSpeciesData is the final 199 speciesData = metaType.cast(existingSpeciesData); 200 } 201 } 202 } else { 203 speciesData = metaType.cast(speciesDataOrReservation); 204 } 205 assert(speciesData != null && speciesData.isResolved()); 206 return speciesData; 207 } 208 209 /** 210 * Meta-data wrapper for concrete subtypes of the top class. 211 * Each concrete subtype corresponds to a given sequence of basic field types (LIJFD). 212 * The fields are immutable; their values are fully specified at object construction. 213 * Each species supplies an array of getter functions which may be used in lambda forms. 214 * A concrete value is always constructed from the full tuple of its field values, 215 * accompanied by the required constructor parameters. 216 * There *may* also be transforms which cloning a species instance and 217 * either replace a constructor parameter or add one or more new field values. 218 * The shortest possible species has zero fields. 219 * Subtypes are not interrelated among themselves by subtyping, even though 220 * it would appear that a shorter species could serve as a supertype of a 221 * longer one which extends it. 222 */ 223 public abstract class SpeciesData { 224 // Bootstrapping requires circular relations Class -> SpeciesData -> Class 225 // Therefore, we need non-final links in the chain. Use @Stable fields. 226 private final K key; 227 private final List<Class<?>> fieldTypes; 228 @Stable private Class<? extends T> speciesCode; 229 @Stable private List<MethodHandle> factories; 230 @Stable private List<MethodHandle> getters; 231 @Stable private List<LambdaForm.NamedFunction> nominalGetters; 232 @Stable private final MethodHandle[] transformHelpers = new MethodHandle[transformMethods.size()]; 233 SpeciesData(K key)234 protected SpeciesData(K key) { 235 this.key = keyType.cast(Objects.requireNonNull(key)); 236 List<Class<?>> types = deriveFieldTypes(key); 237 this.fieldTypes = List.copyOf(types); 238 } 239 key()240 public final K key() { 241 return key; 242 } 243 fieldTypes()244 protected final List<Class<?>> fieldTypes() { 245 return fieldTypes; 246 } 247 fieldCount()248 protected final int fieldCount() { 249 return fieldTypes.size(); 250 } 251 outer()252 protected ClassSpecializer<T,K,S> outer() { 253 return ClassSpecializer.this; 254 } 255 isResolved()256 protected final boolean isResolved() { 257 return speciesCode != null && factories != null && !factories.isEmpty(); 258 } 259 toString()260 @Override public String toString() { 261 return metaType.getSimpleName() + "[" + key.toString() + " => " + (isResolved() ? speciesCode.getSimpleName() : "UNRESOLVED") + "]"; 262 } 263 264 @Override hashCode()265 public int hashCode() { 266 return key.hashCode(); 267 } 268 269 @Override equals(Object obj)270 public boolean equals(Object obj) { 271 if (!(obj instanceof ClassSpecializer.SpeciesData)) { 272 return false; 273 } 274 @SuppressWarnings("rawtypes") 275 ClassSpecializer.SpeciesData that = (ClassSpecializer.SpeciesData) obj; 276 return this.outer() == that.outer() && this.key.equals(that.key); 277 } 278 279 /** Throws NPE if this species is not yet resolved. */ speciesCode()280 protected final Class<? extends T> speciesCode() { 281 return Objects.requireNonNull(speciesCode); 282 } 283 284 /** 285 * Return a {@link MethodHandle} which can get the indexed field of this species. 286 * The return type is the type of the species field it accesses. 287 * The argument type is the {@code fieldHolder} class of this species. 288 */ getter(int i)289 protected MethodHandle getter(int i) { 290 return getters.get(i); 291 } 292 293 /** 294 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that 295 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding 296 * getter. 297 */ getterFunction(int i)298 protected LambdaForm.NamedFunction getterFunction(int i) { 299 LambdaForm.NamedFunction nf = nominalGetters.get(i); 300 assert(nf.memberDeclaringClassOrNull() == speciesCode()); 301 assert(nf.returnType() == BasicType.basicType(fieldTypes.get(i))); 302 return nf; 303 } 304 getterFunctions()305 protected List<LambdaForm.NamedFunction> getterFunctions() { 306 return nominalGetters; 307 } 308 getters()309 protected List<MethodHandle> getters() { 310 return getters; 311 } 312 factory()313 protected MethodHandle factory() { 314 return factories.get(0); 315 } 316 transformHelper(int whichtm)317 protected MethodHandle transformHelper(int whichtm) { 318 MethodHandle mh = transformHelpers[whichtm]; 319 if (mh != null) return mh; 320 mh = deriveTransformHelper(transformMethods().get(whichtm), whichtm); 321 // Do a little type checking before we start using the MH. 322 // (It will be called with invokeBasic, so this is our only chance.) 323 final MethodType mt = transformHelperType(whichtm); 324 mh = mh.asType(mt); 325 return transformHelpers[whichtm] = mh; 326 } 327 transformHelperType(int whichtm)328 private final MethodType transformHelperType(int whichtm) { 329 MemberName tm = transformMethods().get(whichtm); 330 ArrayList<Class<?>> args = new ArrayList<>(); 331 ArrayList<Class<?>> fields = new ArrayList<>(); 332 Collections.addAll(args, tm.getParameterTypes()); 333 fields.addAll(fieldTypes()); 334 List<Class<?>> helperArgs = deriveTransformHelperArguments(tm, whichtm, args, fields); 335 return MethodType.methodType(tm.getReturnType(), helperArgs); 336 } 337 338 // Hooks for subclasses: 339 340 /** 341 * Given a key, derive the list of field types, which all instances of this 342 * species must store. 343 */ deriveFieldTypes(K key)344 protected abstract List<Class<?>> deriveFieldTypes(K key); 345 346 /** 347 * Given the index of a method in the transforms list, supply a factory 348 * method that takes the arguments of the transform, plus the local fields, 349 * and produce a value of the required type. 350 * You can override this to return null or throw if there are no transforms. 351 * This method exists so that the transforms can be "grown" lazily. 352 * This is necessary if the transform *adds* a field to an instance, 353 * which sometimtes requires the creation, on the fly, of an extended species. 354 * This method is only called once for any particular parameter. 355 * The species caches the result in a private array. 356 * 357 * @param transform the transform being implemented 358 * @param whichtm the index of that transform in the original list of transforms 359 * @return the method handle which creates a new result from a mix of transform 360 * arguments and field values 361 */ deriveTransformHelper(MemberName transform, int whichtm)362 protected abstract MethodHandle deriveTransformHelper(MemberName transform, int whichtm); 363 364 /** 365 * During code generation, this method is called once per transform to determine 366 * what is the mix of arguments to hand to the transform-helper. The bytecode 367 * which marshals these arguments is open-coded in the species-specific transform. 368 * The two lists are of opaque objects, which you shouldn't do anything with besides 369 * reordering them into the output list. (They are both mutable, to make editing 370 * easier.) The imputed types of the args correspond to the transform's parameter 371 * list, while the imputed types of the fields correspond to the species field types. 372 * After code generation, this method may be called occasionally by error-checking code. 373 * 374 * @param transform the transform being implemented 375 * @param whichtm the index of that transform in the original list of transforms 376 * @param args a list of opaque objects representing the incoming transform arguments 377 * @param fields a list of opaque objects representing the field values of the receiver 378 * @param <X> the common element type of the various lists 379 * @return a new list 380 */ deriveTransformHelperArguments(MemberName transform, int whichtm, List<X> args, List<X> fields)381 protected abstract <X> List<X> deriveTransformHelperArguments(MemberName transform, int whichtm, 382 List<X> args, List<X> fields); 383 384 /** Given a key, generate the name of the class which implements the species for that key. 385 * This algorithm must be stable. 386 * 387 * @return class name, which by default is {@code outer().topClass().getName() + "$Species_" + deriveTypeString(key)} 388 */ deriveClassName()389 protected String deriveClassName() { 390 return outer().topClass().getName() + "$Species_" + deriveTypeString(); 391 } 392 393 /** 394 * Default implementation collects basic type characters, 395 * plus possibly type names, if some types don't correspond 396 * to basic types. 397 * 398 * @return a string suitable for use in a class name 399 */ deriveTypeString()400 protected String deriveTypeString() { 401 List<Class<?>> types = fieldTypes(); 402 StringBuilder buf = new StringBuilder(); 403 StringBuilder end = new StringBuilder(); 404 for (Class<?> type : types) { 405 BasicType basicType = BasicType.basicType(type); 406 if (basicType.basicTypeClass() == type) { 407 buf.append(basicType.basicTypeChar()); 408 } else { 409 buf.append('V'); 410 end.append(classSig(type)); 411 } 412 } 413 String typeString; 414 if (end.length() > 0) { 415 typeString = BytecodeName.toBytecodeName(buf.append("_").append(end).toString()); 416 } else { 417 typeString = buf.toString(); 418 } 419 return LambdaForm.shortenSignature(typeString); 420 } 421 422 /** 423 * Report what immediate super-class to use for the concrete class of this species. 424 * Normally this is {@code topClass}, but if that is an interface, the factory must override. 425 * The super-class must provide a constructor which takes the {@code baseConstructorType} arguments, if any. 426 * This hook also allows the code generator to use more than one canned supertype for species. 427 * 428 * @return the super-class of the class to be generated 429 */ deriveSuperClass()430 protected Class<? extends T> deriveSuperClass() { 431 final Class<T> topc = topClass(); 432 if (!topClassIsSuper) { 433 try { 434 final Constructor<T> con = reflectConstructor(topc, baseConstructorType().parameterArray()); 435 if (!topc.isInterface() && !Modifier.isPrivate(con.getModifiers())) { 436 topClassIsSuper = true; 437 } 438 } catch (Exception|InternalError ex) { 439 // fall through... 440 } 441 if (!topClassIsSuper) { 442 throw newInternalError("must override if the top class cannot serve as a super class"); 443 } 444 } 445 return topc; 446 } 447 } 448 newSpeciesData(K key)449 protected abstract S newSpeciesData(K key); 450 topSpeciesKey()451 protected K topSpeciesKey() { 452 return null; // null means don't report a top species 453 } 454 455 /** 456 * Code generation support for instances. 457 * Subclasses can modify the behavior. 458 */ 459 public class Factory { 460 /** 461 * Get a concrete subclass of the top class for a given combination of bound types. 462 * 463 * @param speciesData the species requiring the class, not yet linked 464 * @return a linked version of the same species 465 */ loadSpecies(S speciesData)466 S loadSpecies(S speciesData) { 467 String className = speciesData.deriveClassName(); 468 assert(className.indexOf('/') < 0) : className; 469 Class<?> salvage = null; 470 try { 471 salvage = BootLoader.loadClassOrNull(className); 472 if (TRACE_RESOLVE && salvage != null) { 473 // Used by jlink species pregeneration plugin, see 474 // jdk.tools.jlink.internal.plugins.GenerateJLIClassesPlugin 475 System.out.println("[SPECIES_RESOLVE] " + className + " (salvaged)"); 476 } 477 } catch (Error ex) { 478 if (TRACE_RESOLVE) { 479 System.out.println("[SPECIES_FRESOLVE] " + className + " (Error) " + ex.getMessage()); 480 } 481 } 482 final Class<? extends T> speciesCode; 483 if (salvage != null) { 484 speciesCode = salvage.asSubclass(topClass()); 485 linkSpeciesDataToCode(speciesData, speciesCode); 486 linkCodeToSpeciesData(speciesCode, speciesData, true); 487 } else { 488 // Not pregenerated, generate the class 489 try { 490 speciesCode = generateConcreteSpeciesCode(className, speciesData); 491 if (TRACE_RESOLVE) { 492 // Used by jlink species pregeneration plugin, see 493 // jdk.tools.jlink.internal.plugins.GenerateJLIClassesPlugin 494 System.out.println("[SPECIES_RESOLVE] " + className + " (generated)"); 495 } 496 // This operation causes a lot of churn: 497 linkSpeciesDataToCode(speciesData, speciesCode); 498 // This operation commits the relation, but causes little churn: 499 linkCodeToSpeciesData(speciesCode, speciesData, false); 500 } catch (Error ex) { 501 if (TRACE_RESOLVE) { 502 System.out.println("[SPECIES_RESOLVE] " + className + " (Error #2)" ); 503 } 504 // We can get here if there is a race condition loading a class. 505 // Or maybe we are out of resources. Back out of the CHM.get and retry. 506 throw ex; 507 } 508 } 509 510 if (!speciesData.isResolved()) { 511 throw newInternalError("bad species class linkage for " + className + ": " + speciesData); 512 } 513 assert(speciesData == loadSpeciesDataFromCode(speciesCode)); 514 return speciesData; 515 } 516 517 /** 518 * Generate a concrete subclass of the top class for a given combination of bound types. 519 * 520 * A concrete species subclass roughly matches the following schema: 521 * 522 * <pre> 523 * class Species_[[types]] extends [[T]] { 524 * final [[S]] speciesData() { return ... } 525 * static [[T]] make([[fields]]) { return ... } 526 * [[fields]] 527 * final [[T]] transform([[args]]) { return ... } 528 * } 529 * </pre> 530 * 531 * The {@code [[types]]} signature is precisely the key for the species. 532 * 533 * The {@code [[fields]]} section consists of one field definition per character in 534 * the type signature, adhering to the naming schema described in the definition of 535 * {@link #chooseFieldName}. 536 * 537 * For example, a concrete species for two references and one integral bound value 538 * has a shape like the following: 539 * 540 * <pre> 541 * class TopClass { ... private static 542 * final class Species_LLI extends TopClass { 543 * final Object argL0; 544 * final Object argL1; 545 * final int argI2; 546 * private Species_LLI(CT ctarg, ..., Object argL0, Object argL1, int argI2) { 547 * super(ctarg, ...); 548 * this.argL0 = argL0; 549 * this.argL1 = argL1; 550 * this.argI2 = argI2; 551 * } 552 * final SpeciesData speciesData() { return BMH_SPECIES; } 553 * @Stable static SpeciesData BMH_SPECIES; // injected afterwards 554 * static TopClass make(CT ctarg, ..., Object argL0, Object argL1, int argI2) { 555 * return new Species_LLI(ctarg, ..., argL0, argL1, argI2); 556 * } 557 * final TopClass copyWith(CT ctarg, ...) { 558 * return new Species_LLI(ctarg, ..., argL0, argL1, argI2); 559 * } 560 * // two transforms, for the sake of illustration: 561 * final TopClass copyWithExtendL(CT ctarg, ..., Object narg) { 562 * return BMH_SPECIES.transform(L_TYPE).invokeBasic(ctarg, ..., argL0, argL1, argI2, narg); 563 * } 564 * final TopClass copyWithExtendI(CT ctarg, ..., int narg) { 565 * return BMH_SPECIES.transform(I_TYPE).invokeBasic(ctarg, ..., argL0, argL1, argI2, narg); 566 * } 567 * } 568 * </pre> 569 * 570 * @param className of the species 571 * @param speciesData what species we are generating 572 * @return the generated concrete TopClass class 573 */ 574 Class<? extends T> generateConcreteSpeciesCode(String className, ClassSpecializer<T,K,S>.SpeciesData speciesData) { 575 byte[] classFile = generateConcreteSpeciesCodeFile(className, speciesData); 576 577 // load class 578 InvokerBytecodeGenerator.maybeDump(classBCName(className), classFile); 579 Class<?> speciesCode; 580 581 ClassLoader cl = topClass().getClassLoader(); 582 ProtectionDomain pd = null; 583 if (cl != null) { 584 pd = AccessController.doPrivileged( 585 new PrivilegedAction<>() { 586 @Override 587 public ProtectionDomain run() { 588 return topClass().getProtectionDomain(); 589 } 590 }); 591 } 592 try { 593 speciesCode = UNSAFE.defineClass(className, classFile, 0, classFile.length, cl, pd); 594 } catch (Exception ex) { 595 throw newInternalError(ex); 596 } 597 598 return speciesCode.asSubclass(topClass()); 599 } 600 601 // These are named like constants because there is only one per specialization scheme: 602 private final String SPECIES_DATA = classBCName(metaType); 603 private final String SPECIES_DATA_SIG = classSig(SPECIES_DATA); 604 private final String SPECIES_DATA_NAME = sdAccessor.getName(); 605 private final int SPECIES_DATA_MODS = sdAccessor.getModifiers(); 606 private final List<String> TRANSFORM_NAMES; // derived from transformMethods 607 private final List<MethodType> TRANSFORM_TYPES; 608 private final List<Integer> TRANSFORM_MODS; 609 { 610 // Tear apart transformMethods to get the names, types, and modifiers. 611 List<String> tns = new ArrayList<>(); 612 List<MethodType> tts = new ArrayList<>(); 613 List<Integer> tms = new ArrayList<>(); 614 for (int i = 0; i < transformMethods.size(); i++) { 615 MemberName tm = transformMethods.get(i); 616 tns.add(tm.getName()); 617 final MethodType tt = tm.getMethodType(); 618 tts.add(tt); 619 tms.add(tm.getModifiers()); 620 } 621 TRANSFORM_NAMES = List.of(tns.toArray(new String[0])); 622 TRANSFORM_TYPES = List.of(tts.toArray(new MethodType[0])); 623 TRANSFORM_MODS = List.of(tms.toArray(new Integer[0])); 624 } 625 private static final int ACC_PPP = ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED; 626 627 /*non-public*/ byte[] generateConcreteSpeciesCodeFile(String className0, ClassSpecializer<T,K,S>.SpeciesData speciesData) { 628 final String className = classBCName(className0); 629 final String superClassName = classBCName(speciesData.deriveSuperClass()); 630 631 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 632 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 633 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, superClassName, null); 634 635 final String sourceFile = className.substring(className.lastIndexOf('.')+1); 636 cw.visitSource(sourceFile, null); 637 638 // emit static types and BMH_SPECIES fields 639 FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, sdFieldName, SPECIES_DATA_SIG, null, null); 640 fw.visitAnnotation(STABLE_SIG, true); 641 fw.visitEnd(); 642 643 // handy holder for dealing with groups of typed values (ctor arguments and fields) 644 class Var { 645 final int index; 646 final String name; 647 final Class<?> type; 648 final String desc; 649 final BasicType basicType; 650 final int slotIndex; 651 Var(int index, int slotIndex) { 652 this.index = index; 653 this.slotIndex = slotIndex; 654 name = null; type = null; desc = null; 655 basicType = BasicType.V_TYPE; 656 } 657 Var(String name, Class<?> type, Var prev) { 658 int slotIndex = prev.nextSlotIndex(); 659 int index = prev.nextIndex(); 660 if (name == null) name = "x"; 661 if (name.endsWith("#")) 662 name = name.substring(0, name.length()-1) + index; 663 assert(!type.equals(void.class)); 664 String desc = classSig(type); 665 BasicType basicType = BasicType.basicType(type); 666 this.index = index; 667 this.name = name; 668 this.type = type; 669 this.desc = desc; 670 this.basicType = basicType; 671 this.slotIndex = slotIndex; 672 } 673 Var lastOf(List<Var> vars) { 674 int n = vars.size(); 675 return (n == 0 ? this : vars.get(n-1)); 676 } 677 <X> List<Var> fromTypes(List<X> types) { 678 Var prev = this; 679 ArrayList<Var> result = new ArrayList<>(types.size()); 680 int i = 0; 681 for (X x : types) { 682 String vn = name; 683 Class<?> vt; 684 if (x instanceof Class) { 685 vt = (Class<?>) x; 686 // make the names friendlier if debugging 687 assert((vn = vn + "_" + (i++)) != null); 688 } else { 689 @SuppressWarnings("unchecked") 690 Var v = (Var) x; 691 vn = v.name; 692 vt = v.type; 693 } 694 prev = new Var(vn, vt, prev); 695 result.add(prev); 696 } 697 return result; 698 } 699 700 int slotSize() { return basicType.basicTypeSlots(); } 701 int nextIndex() { return index + (slotSize() == 0 ? 0 : 1); } 702 int nextSlotIndex() { return slotIndex >= 0 ? slotIndex + slotSize() : slotIndex; } 703 boolean isInHeap() { return slotIndex < 0; } 704 void emitVarInstruction(int asmop, MethodVisitor mv) { 705 if (asmop == ALOAD) 706 asmop = typeLoadOp(basicType.basicTypeChar()); 707 else 708 throw new AssertionError("bad op="+asmop+" for desc="+desc); 709 mv.visitVarInsn(asmop, slotIndex); 710 } 711 public void emitFieldInsn(int asmop, MethodVisitor mv) { 712 mv.visitFieldInsn(asmop, className, name, desc); 713 } 714 } 715 716 final Var NO_THIS = new Var(0, 0), 717 AFTER_THIS = new Var(0, 1), 718 IN_HEAP = new Var(0, -1); 719 720 // figure out the field types 721 final List<Class<?>> fieldTypes = speciesData.fieldTypes(); 722 final List<Var> fields = new ArrayList<>(fieldTypes.size()); 723 { 724 Var nextF = IN_HEAP; 725 for (Class<?> ft : fieldTypes) { 726 String fn = chooseFieldName(ft, nextF.nextIndex()); 727 nextF = new Var(fn, ft, nextF); 728 fields.add(nextF); 729 } 730 } 731 732 // emit bound argument fields 733 for (Var field : fields) { 734 cw.visitField(ACC_FINAL, field.name, field.desc, null, null).visitEnd(); 735 } 736 737 MethodVisitor mv; 738 739 // emit implementation of speciesData() 740 mv = cw.visitMethod((SPECIES_DATA_MODS & ACC_PPP) + ACC_FINAL, 741 SPECIES_DATA_NAME, "()" + SPECIES_DATA_SIG, null, null); 742 mv.visitCode(); 743 mv.visitFieldInsn(GETSTATIC, className, sdFieldName, SPECIES_DATA_SIG); 744 mv.visitInsn(ARETURN); 745 mv.visitMaxs(0, 0); 746 mv.visitEnd(); 747 748 // figure out the constructor arguments 749 MethodType superCtorType = ClassSpecializer.this.baseConstructorType(); 750 MethodType thisCtorType = superCtorType.appendParameterTypes(fieldTypes); 751 752 // emit constructor 753 { 754 mv = cw.visitMethod(ACC_PRIVATE, 755 "<init>", methodSig(thisCtorType), null, null); 756 mv.visitCode(); 757 mv.visitVarInsn(ALOAD, 0); // this 758 759 final List<Var> ctorArgs = AFTER_THIS.fromTypes(superCtorType.parameterList()); 760 for (Var ca : ctorArgs) { 761 ca.emitVarInstruction(ALOAD, mv); 762 } 763 764 // super(ca...) 765 mv.visitMethodInsn(INVOKESPECIAL, superClassName, 766 "<init>", methodSig(superCtorType), false); 767 768 // store down fields 769 Var lastFV = AFTER_THIS.lastOf(ctorArgs); 770 for (Var f : fields) { 771 // this.argL1 = argL1 772 mv.visitVarInsn(ALOAD, 0); // this 773 lastFV = new Var(f.name, f.type, lastFV); 774 lastFV.emitVarInstruction(ALOAD, mv); 775 f.emitFieldInsn(PUTFIELD, mv); 776 } 777 778 mv.visitInsn(RETURN); 779 mv.visitMaxs(0, 0); 780 mv.visitEnd(); 781 } 782 783 // emit make() ...factory method wrapping constructor 784 { 785 MethodType ftryType = thisCtorType.changeReturnType(topClass()); 786 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, 787 "make", methodSig(ftryType), null, null); 788 mv.visitCode(); 789 // make instance 790 mv.visitTypeInsn(NEW, className); 791 mv.visitInsn(DUP); 792 // load factory method arguments: ctarg... and arg... 793 for (Var v : NO_THIS.fromTypes(ftryType.parameterList())) { 794 v.emitVarInstruction(ALOAD, mv); 795 } 796 797 // finally, invoke the constructor and return 798 mv.visitMethodInsn(INVOKESPECIAL, className, 799 "<init>", methodSig(thisCtorType), false); 800 mv.visitInsn(ARETURN); 801 mv.visitMaxs(0, 0); 802 mv.visitEnd(); 803 } 804 805 // For each transform, emit the customized override of the transform method. 806 // This method mixes together some incoming arguments (from the transform's 807 // static type signature) with the field types themselves, and passes 808 // the resulting mish-mosh of values to a method handle produced by 809 // the species itself. (Typically this method handle is the factory 810 // method of this species or a related one.) 811 for (int whichtm = 0; whichtm < TRANSFORM_NAMES.size(); whichtm++) { 812 final String TNAME = TRANSFORM_NAMES.get(whichtm); 813 final MethodType TTYPE = TRANSFORM_TYPES.get(whichtm); 814 final int TMODS = TRANSFORM_MODS.get(whichtm); 815 mv = cw.visitMethod((TMODS & ACC_PPP) | ACC_FINAL, 816 TNAME, TTYPE.toMethodDescriptorString(), null, E_THROWABLE); 817 mv.visitCode(); 818 // return a call to the corresponding "transform helper", something like this: 819 // MY_SPECIES.transformHelper(whichtm).invokeBasic(ctarg, ..., argL0, ..., xarg) 820 mv.visitFieldInsn(GETSTATIC, className, 821 sdFieldName, SPECIES_DATA_SIG); 822 emitIntConstant(whichtm, mv); 823 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, 824 "transformHelper", "(I)" + MH_SIG, false); 825 826 List<Var> targs = AFTER_THIS.fromTypes(TTYPE.parameterList()); 827 List<Var> tfields = new ArrayList<>(fields); 828 // mix them up and load them for the transform helper: 829 List<Var> helperArgs = speciesData.deriveTransformHelperArguments(transformMethods.get(whichtm), whichtm, targs, tfields); 830 List<Class<?>> helperTypes = new ArrayList<>(helperArgs.size()); 831 for (Var ha : helperArgs) { 832 helperTypes.add(ha.basicType.basicTypeClass()); 833 if (ha.isInHeap()) { 834 assert(tfields.contains(ha)); 835 mv.visitVarInsn(ALOAD, 0); 836 ha.emitFieldInsn(GETFIELD, mv); 837 } else { 838 assert(targs.contains(ha)); 839 ha.emitVarInstruction(ALOAD, mv); 840 } 841 } 842 843 // jump into the helper (which is probably a factory method) 844 final Class<?> rtype = TTYPE.returnType(); 845 final BasicType rbt = BasicType.basicType(rtype); 846 MethodType invokeBasicType = MethodType.methodType(rbt.basicTypeClass(), helperTypes); 847 mv.visitMethodInsn(INVOKEVIRTUAL, MH, 848 "invokeBasic", methodSig(invokeBasicType), false); 849 if (rbt == BasicType.L_TYPE) { 850 mv.visitTypeInsn(CHECKCAST, classBCName(rtype)); 851 mv.visitInsn(ARETURN); 852 } else { 853 throw newInternalError("NYI: transform of type "+rtype); 854 } 855 mv.visitMaxs(0, 0); 856 mv.visitEnd(); 857 } 858 859 cw.visitEnd(); 860 861 return cw.toByteArray(); 862 } 863 864 private int typeLoadOp(char t) { 865 switch (t) { 866 case 'L': return ALOAD; 867 case 'I': return ILOAD; 868 case 'J': return LLOAD; 869 case 'F': return FLOAD; 870 case 'D': return DLOAD; 871 default : throw newInternalError("unrecognized type " + t); 872 } 873 } 874 875 private void emitIntConstant(int con, MethodVisitor mv) { 876 if (ICONST_M1 - ICONST_0 <= con && con <= ICONST_5 - ICONST_0) 877 mv.visitInsn(ICONST_0 + con); 878 else if (con == (byte) con) 879 mv.visitIntInsn(BIPUSH, con); 880 else if (con == (short) con) 881 mv.visitIntInsn(SIPUSH, con); 882 else { 883 mv.visitLdcInsn(con); 884 } 885 886 } 887 888 // 889 // Getter MH generation. 890 // 891 892 private MethodHandle findGetter(Class<?> speciesCode, List<Class<?>> types, int index) { 893 Class<?> fieldType = types.get(index); 894 String fieldName = chooseFieldName(fieldType, index); 895 try { 896 return IMPL_LOOKUP.findGetter(speciesCode, fieldName, fieldType); 897 } catch (NoSuchFieldException | IllegalAccessException e) { 898 throw newInternalError(e); 899 } 900 } 901 902 private List<MethodHandle> findGetters(Class<?> speciesCode, List<Class<?>> types) { 903 MethodHandle[] mhs = new MethodHandle[types.size()]; 904 for (int i = 0; i < mhs.length; ++i) { 905 mhs[i] = findGetter(speciesCode, types, i); 906 assert(mhs[i].internalMemberName().getDeclaringClass() == speciesCode); 907 } 908 return List.of(mhs); 909 } 910 911 private List<MethodHandle> findFactories(Class<? extends T> speciesCode, List<Class<?>> types) { 912 MethodHandle[] mhs = new MethodHandle[1]; 913 mhs[0] = findFactory(speciesCode, types); 914 return List.of(mhs); 915 } 916 917 List<LambdaForm.NamedFunction> makeNominalGetters(List<Class<?>> types, List<MethodHandle> getters) { 918 LambdaForm.NamedFunction[] nfs = new LambdaForm.NamedFunction[types.size()]; 919 for (int i = 0; i < nfs.length; ++i) { 920 nfs[i] = new LambdaForm.NamedFunction(getters.get(i)); 921 } 922 return List.of(nfs); 923 } 924 925 // 926 // Auxiliary methods. 927 // 928 929 protected void linkSpeciesDataToCode(ClassSpecializer<T,K,S>.SpeciesData speciesData, Class<? extends T> speciesCode) { 930 speciesData.speciesCode = speciesCode.asSubclass(topClass); 931 final List<Class<?>> types = speciesData.fieldTypes; 932 speciesData.factories = this.findFactories(speciesCode, types); 933 speciesData.getters = this.findGetters(speciesCode, types); 934 speciesData.nominalGetters = this.makeNominalGetters(types, speciesData.getters); 935 } 936 937 private Field reflectSDField(Class<? extends T> speciesCode) { 938 final Field field = reflectField(speciesCode, sdFieldName); 939 assert(field.getType() == metaType); 940 assert(Modifier.isStatic(field.getModifiers())); 941 return field; 942 } 943 944 private S readSpeciesDataFromCode(Class<? extends T> speciesCode) { 945 try { 946 MemberName sdField = IMPL_LOOKUP.resolveOrFail(REF_getStatic, speciesCode, sdFieldName, metaType); 947 Object base = MethodHandleNatives.staticFieldBase(sdField); 948 long offset = MethodHandleNatives.staticFieldOffset(sdField); 949 UNSAFE.loadFence(); 950 return metaType.cast(UNSAFE.getObject(base, offset)); 951 } catch (Error err) { 952 throw err; 953 } catch (Exception ex) { 954 throw newInternalError("Failed to load speciesData from speciesCode: " + speciesCode.getName(), ex); 955 } catch (Throwable t) { 956 throw uncaughtException(t); 957 } 958 } 959 960 protected S loadSpeciesDataFromCode(Class<? extends T> speciesCode) { 961 if (speciesCode == topClass()) { 962 return topSpecies; 963 } 964 S result = readSpeciesDataFromCode(speciesCode); 965 if (result.outer() != ClassSpecializer.this) { 966 throw newInternalError("wrong class"); 967 } 968 return result; 969 } 970 971 protected void linkCodeToSpeciesData(Class<? extends T> speciesCode, ClassSpecializer<T,K,S>.SpeciesData speciesData, boolean salvage) { 972 try { 973 assert(readSpeciesDataFromCode(speciesCode) == null || 974 (salvage && readSpeciesDataFromCode(speciesCode).equals(speciesData))); 975 976 MemberName sdField = IMPL_LOOKUP.resolveOrFail(REF_putStatic, speciesCode, sdFieldName, metaType); 977 Object base = MethodHandleNatives.staticFieldBase(sdField); 978 long offset = MethodHandleNatives.staticFieldOffset(sdField); 979 UNSAFE.storeFence(); 980 UNSAFE.putObject(base, offset, speciesData); 981 UNSAFE.storeFence(); 982 } catch (Error err) { 983 throw err; 984 } catch (Exception ex) { 985 throw newInternalError("Failed to link speciesData to speciesCode: " + speciesCode.getName(), ex); 986 } catch (Throwable t) { 987 throw uncaughtException(t); 988 } 989 } 990 991 /** 992 * Field names in concrete species classes adhere to this pattern: 993 * type + index, where type is a single character (L, I, J, F, D). 994 * The factory subclass can customize this. 995 * The name is purely cosmetic, since it applies to a private field. 996 */ 997 protected String chooseFieldName(Class<?> type, int index) { 998 BasicType bt = BasicType.basicType(type); 999 return "" + bt.basicTypeChar() + index; 1000 } 1001 1002 MethodHandle findFactory(Class<? extends T> speciesCode, List<Class<?>> types) { 1003 final MethodType type = baseConstructorType().changeReturnType(topClass()).appendParameterTypes(types); 1004 try { 1005 return IMPL_LOOKUP.findStatic(speciesCode, "make", type); 1006 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) { 1007 throw newInternalError(e); 1008 } 1009 } 1010 } 1011 1012 /** Hook that virtualizes the Factory class, allowing subclasses to extend it. */ 1013 protected Factory makeFactory() { 1014 return new Factory(); 1015 } 1016 1017 1018 // Other misc helpers: 1019 private static final String MH = "java/lang/invoke/MethodHandle"; 1020 private static final String MH_SIG = "L" + MH + ";"; 1021 private static final String STABLE = "jdk/internal/vm/annotation/Stable"; 1022 private static final String STABLE_SIG = "L" + STABLE + ";"; 1023 private static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" }; 1024 static { 1025 assert(MH_SIG.equals(classSig(MethodHandle.class))); 1026 assert(MH.equals(classBCName(MethodHandle.class))); 1027 } 1028 1029 static String methodSig(MethodType mt) { 1030 return mt.toMethodDescriptorString(); 1031 } 1032 static String classSig(Class<?> cls) { 1033 if (cls.isPrimitive() || cls.isArray()) 1034 return MethodType.methodType(cls).toMethodDescriptorString().substring(2); 1035 return classSig(classBCName(cls)); 1036 } 1037 static String classSig(String bcName) { 1038 assert(bcName.indexOf('.') < 0); 1039 assert(!bcName.endsWith(";")); 1040 assert(!bcName.startsWith("[")); 1041 return "L" + bcName + ";"; 1042 } 1043 static String classBCName(Class<?> cls) { 1044 return classBCName(className(cls)); 1045 } 1046 static String classBCName(String str) { 1047 assert(str.indexOf('/') < 0) : str; 1048 return str.replace('.', '/'); 1049 } 1050 static String className(Class<?> cls) { 1051 assert(!cls.isArray() && !cls.isPrimitive()); 1052 return cls.getName(); 1053 } 1054 } 1055