1/* 2 * Copyright (c) 2008, 2016, 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 java.lang.invoke; 27 28import jdk.internal.loader.BootLoader; 29import jdk.internal.org.objectweb.asm.ClassWriter; 30import jdk.internal.org.objectweb.asm.FieldVisitor; 31import jdk.internal.org.objectweb.asm.MethodVisitor; 32import jdk.internal.vm.annotation.Stable; 33import sun.invoke.util.ValueConversions; 34import sun.invoke.util.Wrapper; 35 36import java.lang.invoke.LambdaForm.NamedFunction; 37import java.lang.invoke.MethodHandles.Lookup; 38import java.lang.reflect.Field; 39import java.util.concurrent.ConcurrentHashMap; 40import java.util.concurrent.ConcurrentMap; 41import java.util.function.Function; 42 43import static java.lang.invoke.LambdaForm.BasicType; 44import static java.lang.invoke.LambdaForm.BasicType.*; 45import static java.lang.invoke.MethodHandleStatics.*; 46import static jdk.internal.org.objectweb.asm.Opcodes.*; 47 48/** 49 * The flavor of method handle which emulates an invoke instruction 50 * on a predetermined argument. The JVM dispatches to the correct method 51 * when the handle is created, not when it is invoked. 52 * 53 * All bound arguments are encapsulated in dedicated species. 54 */ 55/*non-public*/ abstract class BoundMethodHandle extends MethodHandle { 56 57 /*non-public*/ BoundMethodHandle(MethodType type, LambdaForm form) { 58 super(type, form); 59 assert(speciesData() == speciesData(form)); 60 } 61 62 // 63 // BMH API and internals 64 // 65 66 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) { 67 // for some type signatures, there exist pre-defined concrete BMH classes 68 try { 69 switch (xtype) { 70 case L_TYPE: 71 return bindSingle(type, form, x); // Use known fast path. 72 case I_TYPE: 73 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(I_TYPE).constructor().invokeBasic(type, form, ValueConversions.widenSubword(x)); 74 case J_TYPE: 75 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(J_TYPE).constructor().invokeBasic(type, form, (long) x); 76 case F_TYPE: 77 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(F_TYPE).constructor().invokeBasic(type, form, (float) x); 78 case D_TYPE: 79 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(D_TYPE).constructor().invokeBasic(type, form, (double) x); 80 default : throw newInternalError("unexpected xtype: " + xtype); 81 } 82 } catch (Throwable t) { 83 throw uncaughtException(t); 84 } 85 } 86 87 /*non-public*/ 88 LambdaFormEditor editor() { 89 return form.editor(); 90 } 91 92 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) { 93 return Species_L.make(type, form, x); 94 } 95 96 @Override // there is a default binder in the super class, for 'L' types only 97 /*non-public*/ 98 BoundMethodHandle bindArgumentL(int pos, Object value) { 99 return editor().bindArgumentL(this, pos, value); 100 } 101 /*non-public*/ 102 BoundMethodHandle bindArgumentI(int pos, int value) { 103 return editor().bindArgumentI(this, pos, value); 104 } 105 /*non-public*/ 106 BoundMethodHandle bindArgumentJ(int pos, long value) { 107 return editor().bindArgumentJ(this, pos, value); 108 } 109 /*non-public*/ 110 BoundMethodHandle bindArgumentF(int pos, float value) { 111 return editor().bindArgumentF(this, pos, value); 112 } 113 /*non-public*/ 114 BoundMethodHandle bindArgumentD(int pos, double value) { 115 return editor().bindArgumentD(this, pos, value); 116 } 117 118 @Override 119 BoundMethodHandle rebind() { 120 if (!tooComplex()) { 121 return this; 122 } 123 return makeReinvoker(this); 124 } 125 126 private boolean tooComplex() { 127 return (fieldCount() > FIELD_COUNT_THRESHOLD || 128 form.expressionCount() > FORM_EXPRESSION_THRESHOLD); 129 } 130 private static final int FIELD_COUNT_THRESHOLD = 12; // largest convenient BMH field count 131 private static final int FORM_EXPRESSION_THRESHOLD = 24; // largest convenient BMH expression count 132 133 /** 134 * A reinvoker MH has this form: 135 * {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }} 136 */ 137 static BoundMethodHandle makeReinvoker(MethodHandle target) { 138 LambdaForm form = DelegatingMethodHandle.makeReinvokerForm( 139 target, MethodTypeForm.LF_REBIND, 140 Species_L.SPECIES_DATA, Species_L.SPECIES_DATA.getterFunction(0)); 141 return Species_L.make(target.type(), form, target); 142 } 143 144 /** 145 * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a 146 * static field containing this value, and they must accordingly implement this method. 147 */ 148 /*non-public*/ abstract SpeciesData speciesData(); 149 150 /*non-public*/ static SpeciesData speciesData(LambdaForm form) { 151 Object c = form.names[0].constraint; 152 if (c instanceof SpeciesData) 153 return (SpeciesData) c; 154 // if there is no BMH constraint, then use the null constraint 155 return SpeciesData.EMPTY; 156 } 157 158 /** 159 * Return the number of fields in this BMH. Equivalent to speciesData().fieldCount(). 160 */ 161 /*non-public*/ abstract int fieldCount(); 162 163 @Override 164 Object internalProperties() { 165 return "\n& BMH="+internalValues(); 166 } 167 168 @Override 169 final String internalValues() { 170 int count = speciesData().fieldCount(); 171 if (count == 1) { 172 return "[" + arg(0) + "]"; 173 } 174 StringBuilder sb = new StringBuilder("["); 175 for (int i = 0; i < count; ++i) { 176 sb.append("\n ").append(i).append(": ( ").append(arg(i)).append(" )"); 177 } 178 return sb.append("\n]").toString(); 179 } 180 181 /*non-public*/ final Object arg(int i) { 182 try { 183 switch (speciesData().fieldType(i)) { 184 case L_TYPE: return speciesData().getters[i].invokeBasic(this); 185 case I_TYPE: return (int) speciesData().getters[i].invokeBasic(this); 186 case J_TYPE: return (long) speciesData().getters[i].invokeBasic(this); 187 case F_TYPE: return (float) speciesData().getters[i].invokeBasic(this); 188 case D_TYPE: return (double) speciesData().getters[i].invokeBasic(this); 189 } 190 } catch (Throwable ex) { 191 throw uncaughtException(ex); 192 } 193 throw new InternalError("unexpected type: " + speciesData().typeChars+"."+i); 194 } 195 196 // 197 // cloning API 198 // 199 200 /*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf); 201 /*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg); 202 /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg); 203 /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg); 204 /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg); 205 /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg); 206 207 // 208 // concrete BMH classes required to close bootstrap loops 209 // 210 211 private // make it private to force users to access the enclosing class first 212 static final class Species_L extends BoundMethodHandle { 213 final Object argL0; 214 private Species_L(MethodType mt, LambdaForm lf, Object argL0) { 215 super(mt, lf); 216 this.argL0 = argL0; 217 } 218 @Override 219 /*non-public*/ SpeciesData speciesData() { 220 return SPECIES_DATA; 221 } 222 @Override 223 /*non-public*/ int fieldCount() { 224 return 1; 225 } 226 /*non-public*/ static final SpeciesData SPECIES_DATA = new SpeciesData("L", Species_L.class); 227 /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) { 228 return new Species_L(mt, lf, argL0); 229 } 230 @Override 231 /*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) { 232 return new Species_L(mt, lf, argL0); 233 } 234 @Override 235 /*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) { 236 try { 237 return (BoundMethodHandle) SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 238 } catch (Throwable ex) { 239 throw uncaughtException(ex); 240 } 241 } 242 @Override 243 /*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) { 244 try { 245 return (BoundMethodHandle) SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 246 } catch (Throwable ex) { 247 throw uncaughtException(ex); 248 } 249 } 250 @Override 251 /*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) { 252 try { 253 return (BoundMethodHandle) SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 254 } catch (Throwable ex) { 255 throw uncaughtException(ex); 256 } 257 } 258 @Override 259 /*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) { 260 try { 261 return (BoundMethodHandle) SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 262 } catch (Throwable ex) { 263 throw uncaughtException(ex); 264 } 265 } 266 @Override 267 /*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) { 268 try { 269 return (BoundMethodHandle) SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 270 } catch (Throwable ex) { 271 throw uncaughtException(ex); 272 } 273 } 274 } 275 276 // 277 // BMH species meta-data 278 // 279 280 /** 281 * Meta-data wrapper for concrete BMH types. 282 * Each BMH type corresponds to a given sequence of basic field types (LIJFD). 283 * The fields are immutable; their values are fully specified at object construction. 284 * Each BMH type supplies an array of getter functions which may be used in lambda forms. 285 * A BMH is constructed by cloning a shorter BMH and adding one or more new field values. 286 * The shortest possible BMH has zero fields; its class is SimpleMethodHandle. 287 * BMH species are not interrelated by subtyping, even though it would appear that 288 * a shorter BMH could serve as a supertype of a longer one which extends it. 289 */ 290 static class SpeciesData { 291 private final String typeChars; 292 private final BasicType[] typeCodes; 293 private final Class<? extends BoundMethodHandle> clazz; 294 // Bootstrapping requires circular relations MH -> BMH -> SpeciesData -> MH 295 // Therefore, we need a non-final link in the chain. Use array elements. 296 @Stable private final MethodHandle[] constructor; 297 @Stable private final MethodHandle[] getters; 298 @Stable private final NamedFunction[] nominalGetters; 299 @Stable private final SpeciesData[] extensions; 300 301 /*non-public*/ int fieldCount() { 302 return typeCodes.length; 303 } 304 /*non-public*/ BasicType fieldType(int i) { 305 return typeCodes[i]; 306 } 307 /*non-public*/ char fieldTypeChar(int i) { 308 return typeChars.charAt(i); 309 } 310 String fieldSignature() { 311 return typeChars; 312 } 313 public Class<? extends BoundMethodHandle> fieldHolder() { 314 return clazz; 315 } 316 public String toString() { 317 return "SpeciesData<"+fieldSignature()+">"; 318 } 319 320 /** 321 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that 322 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding 323 * getter. 324 */ 325 NamedFunction getterFunction(int i) { 326 NamedFunction nf = nominalGetters[i]; 327 assert(nf.memberDeclaringClassOrNull() == fieldHolder()); 328 assert(nf.returnType() == fieldType(i)); 329 return nf; 330 } 331 332 NamedFunction[] getterFunctions() { 333 return nominalGetters; 334 } 335 336 MethodHandle[] getterHandles() { return getters; } 337 338 MethodHandle constructor() { 339 return constructor[0]; 340 } 341 342 static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class); 343 344 SpeciesData(String types, Class<? extends BoundMethodHandle> clazz) { 345 this.typeChars = types; 346 this.typeCodes = basicTypes(types); 347 this.clazz = clazz; 348 if (!INIT_DONE) { 349 this.constructor = new MethodHandle[1]; // only one ctor 350 this.getters = new MethodHandle[types.length()]; 351 this.nominalGetters = new NamedFunction[types.length()]; 352 } else { 353 this.constructor = Factory.makeCtors(clazz, types, null); 354 this.getters = Factory.makeGetters(clazz, types, null); 355 this.nominalGetters = Factory.makeNominalGetters(types, null, this.getters); 356 } 357 this.extensions = new SpeciesData[ARG_TYPE_LIMIT]; 358 } 359 360 private void initForBootstrap() { 361 assert(!INIT_DONE); 362 if (constructor() == null) { 363 String types = typeChars; 364 CACHE.put(types, this); 365 Factory.makeCtors(clazz, types, this.constructor); 366 Factory.makeGetters(clazz, types, this.getters); 367 Factory.makeNominalGetters(types, this.nominalGetters, this.getters); 368 } 369 } 370 371 private static final ConcurrentMap<String, SpeciesData> CACHE = new ConcurrentHashMap<>(); 372 private static final boolean INIT_DONE; // set after <clinit> finishes... 373 374 SpeciesData extendWith(byte type) { 375 return extendWith(BasicType.basicType(type)); 376 } 377 378 SpeciesData extendWith(BasicType type) { 379 int ord = type.ordinal(); 380 SpeciesData d = extensions[ord]; 381 if (d != null) return d; 382 extensions[ord] = d = get(typeChars+type.basicTypeChar()); 383 return d; 384 } 385 386 private static SpeciesData get(String types) { 387 return CACHE.computeIfAbsent(types, new Function<String, SpeciesData>() { 388 @Override 389 public SpeciesData apply(String types) { 390 Class<? extends BoundMethodHandle> bmhcl = Factory.getConcreteBMHClass(types); 391 // SpeciesData instantiation may throw VirtualMachineError because of 392 // code cache overflow... 393 SpeciesData speciesData = new SpeciesData(types, bmhcl); 394 // CHM.computeIfAbsent ensures only one SpeciesData will be set 395 // successfully on the concrete BMH class if ever 396 Factory.setSpeciesDataToConcreteBMHClass(bmhcl, speciesData); 397 // the concrete BMH class is published via SpeciesData instance 398 // returned here only after it's SPECIES_DATA field is set 399 return speciesData; 400 } 401 }); 402 } 403 404 /** 405 * This is to be called when assertions are enabled. It checks whether SpeciesData for all of the statically 406 * defined species subclasses of BoundMethodHandle has been added to the SpeciesData cache. See below in the 407 * static initializer for 408 */ 409 static boolean speciesDataCachePopulated() { 410 Class<BoundMethodHandle> rootCls = BoundMethodHandle.class; 411 for (Class<?> c : rootCls.getDeclaredClasses()) { 412 if (rootCls.isAssignableFrom(c)) { 413 final Class<? extends BoundMethodHandle> cbmh = c.asSubclass(BoundMethodHandle.class); 414 SpeciesData d = Factory.getSpeciesDataFromConcreteBMHClass(cbmh); 415 assert(d != null) : cbmh.getName(); 416 assert(d.clazz == cbmh); 417 assert(CACHE.get(d.typeChars) == d); 418 } 419 } 420 return true; 421 } 422 423 static { 424 // Pre-fill the BMH species-data cache with EMPTY and all BMH's inner subclasses. 425 EMPTY.initForBootstrap(); 426 Species_L.SPECIES_DATA.initForBootstrap(); 427 // check that all static SpeciesData instances have been initialized 428 assert speciesDataCachePopulated(); 429 // Note: Do not simplify this, because INIT_DONE must not be 430 // a compile-time constant during bootstrapping. 431 INIT_DONE = Boolean.TRUE; 432 } 433 } 434 435 static SpeciesData getSpeciesData(String types) { 436 return SpeciesData.get(types); 437 } 438 439 /** 440 * Generation of concrete BMH classes. 441 * 442 * A concrete BMH species is fit for binding a number of values adhering to a 443 * given type pattern. Reference types are erased. 444 * 445 * BMH species are cached by type pattern. 446 * 447 * A BMH species has a number of fields with the concrete (possibly erased) types of 448 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs, 449 * which can be included as names in lambda forms. 450 */ 451 static class Factory { 452 453 private static final String JLO_SIG = "Ljava/lang/Object;"; 454 private static final String MH = "java/lang/invoke/MethodHandle"; 455 private static final String MH_SIG = "L"+MH+";"; 456 private static final String BMH = "java/lang/invoke/BoundMethodHandle"; 457 private static final String BMH_NAME = "java.lang.invoke.BoundMethodHandle"; 458 private static final String BMH_SIG = "L"+BMH+";"; 459 private static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData"; 460 private static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";"; 461 private static final String STABLE_SIG = "Ljdk/internal/vm/annotation/Stable;"; 462 463 private static final String SPECIES_PREFIX_NAME = "Species_"; 464 private static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME; 465 private static final String SPECIES_CLASS_PREFIX = BMH_NAME + "$" + SPECIES_PREFIX_NAME; 466 467 private static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG; 468 private static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG; 469 private static final String INT_SIG = "()I"; 470 471 private static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;"; 472 473 private static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" }; 474 475 private static final ConcurrentMap<String, Class<? extends BoundMethodHandle>> CLASS_CACHE = new ConcurrentHashMap<>(); 476 477 /** 478 * Get a concrete subclass of BMH for a given combination of bound types. 479 * 480 * @param types the type signature, wherein reference types are erased to 'L' 481 * @return the concrete BMH class 482 */ 483 static Class<? extends BoundMethodHandle> getConcreteBMHClass(String types) { 484 // CHM.computeIfAbsent ensures generateConcreteBMHClass is called 485 // only once per key. 486 return CLASS_CACHE.computeIfAbsent( 487 types, new Function<String, Class<? extends BoundMethodHandle>>() { 488 @Override 489 public Class<? extends BoundMethodHandle> apply(String types) { 490 String shortTypes = LambdaForm.shortenSignature(types); 491 String className = SPECIES_CLASS_PREFIX + shortTypes; 492 Class<?> c = BootLoader.loadClassOrNull(className); 493 if (TRACE_RESOLVE) { 494 System.out.println("[BMH_RESOLVE] " + shortTypes + 495 (c != null ? " (success)" : " (fail)") ); 496 } 497 if (c != null) { 498 return c.asSubclass(BoundMethodHandle.class); 499 } else { 500 // Not pregenerated, generate the class 501 return generateConcreteBMHClass(shortTypes, types); 502 } 503 } 504 }); 505 } 506 507 /** 508 * Generate a concrete subclass of BMH for a given combination of bound types. 509 * 510 * A concrete BMH species adheres to the following schema: 511 * 512 * <pre> 513 * class Species_[[types]] extends BoundMethodHandle { 514 * [[fields]] 515 * final SpeciesData speciesData() { return SpeciesData.get("[[types]]"); } 516 * } 517 * </pre> 518 * 519 * The {@code [[types]]} signature is precisely the string that is passed to this 520 * method. 521 * 522 * The {@code [[fields]]} section consists of one field definition per character in 523 * the type signature, adhering to the naming schema described in the definition of 524 * {@link #makeFieldName}. 525 * 526 * For example, a concrete BMH species for two reference and one integral bound values 527 * would have the following shape: 528 * 529 * <pre> 530 * class BoundMethodHandle { ... private static 531 * final class Species_LLI extends BoundMethodHandle { 532 * final Object argL0; 533 * final Object argL1; 534 * final int argI2; 535 * private Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) { 536 * super(mt, lf); 537 * this.argL0 = argL0; 538 * this.argL1 = argL1; 539 * this.argI2 = argI2; 540 * } 541 * final SpeciesData speciesData() { return SPECIES_DATA; } 542 * final int fieldCount() { return 3; } 543 * @Stable static SpeciesData SPECIES_DATA; // injected afterwards 544 * static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) { 545 * return new Species_LLI(mt, lf, argL0, argL1, argI2); 546 * } 547 * final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) { 548 * return new Species_LLI(mt, lf, argL0, argL1, argI2); 549 * } 550 * final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) { 551 * return SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg); 552 * } 553 * final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) { 554 * return SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg); 555 * } 556 * final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) { 557 * return SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg); 558 * } 559 * final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) { 560 * return SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg); 561 * } 562 * public final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) { 563 * return SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg); 564 * } 565 * } 566 * </pre> 567 * 568 * @param types the type signature, wherein reference types are erased to 'L' 569 * @return the generated concrete BMH class 570 */ 571 static Class<? extends BoundMethodHandle> generateConcreteBMHClass(String shortTypes, 572 String types) { 573 final String className = speciesInternalClassName(shortTypes); 574 byte[] classFile = generateConcreteBMHClassBytes(shortTypes, types, className); 575 576 // load class 577 InvokerBytecodeGenerator.maybeDump(className, classFile); 578 Class<? extends BoundMethodHandle> bmhClass = 579 UNSAFE.defineClass(className, classFile, 0, classFile.length, 580 BoundMethodHandle.class.getClassLoader(), null) 581 .asSubclass(BoundMethodHandle.class); 582 583 return bmhClass; 584 } 585 586 static String speciesInternalClassName(String shortTypes) { 587 return SPECIES_PREFIX_PATH + shortTypes; 588 } 589 590 static byte[] generateConcreteBMHClassBytes(final String shortTypes, 591 final String types, final String className) { 592 final String sourceFile = SPECIES_PREFIX_NAME + shortTypes; 593 594 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 595 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 596 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null); 597 cw.visitSource(sourceFile, null); 598 599 // emit static types and SPECIES_DATA fields 600 FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null); 601 fw.visitAnnotation(STABLE_SIG, true); 602 fw.visitEnd(); 603 604 // emit bound argument fields 605 for (int i = 0; i < types.length(); ++i) { 606 final char t = types.charAt(i); 607 final String fieldName = makeFieldName(types, i); 608 final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t); 609 cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd(); 610 } 611 612 MethodVisitor mv; 613 614 // emit constructor 615 mv = cw.visitMethod(ACC_PRIVATE, "<init>", makeSignature(types, true), null, null); 616 mv.visitCode(); 617 mv.visitVarInsn(ALOAD, 0); // this 618 mv.visitVarInsn(ALOAD, 1); // type 619 mv.visitVarInsn(ALOAD, 2); // form 620 621 mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false); 622 623 for (int i = 0, j = 0; i < types.length(); ++i, ++j) { 624 // i counts the arguments, j counts corresponding argument slots 625 char t = types.charAt(i); 626 mv.visitVarInsn(ALOAD, 0); 627 mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3 628 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t)); 629 if (t == 'J' || t == 'D') { 630 ++j; // adjust argument register access 631 } 632 } 633 634 mv.visitInsn(RETURN); 635 mv.visitMaxs(0, 0); 636 mv.visitEnd(); 637 638 // emit implementation of speciesData() 639 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null); 640 mv.visitCode(); 641 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); 642 mv.visitInsn(ARETURN); 643 mv.visitMaxs(0, 0); 644 mv.visitEnd(); 645 646 // emit implementation of fieldCount() 647 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null); 648 mv.visitCode(); 649 int fc = types.length(); 650 if (fc <= (ICONST_5 - ICONST_0)) { 651 mv.visitInsn(ICONST_0 + fc); 652 } else { 653 mv.visitIntInsn(SIPUSH, fc); 654 } 655 mv.visitInsn(IRETURN); 656 mv.visitMaxs(0, 0); 657 mv.visitEnd(); 658 // emit make() ...factory method wrapping constructor 659 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null); 660 mv.visitCode(); 661 // make instance 662 mv.visitTypeInsn(NEW, className); 663 mv.visitInsn(DUP); 664 // load mt, lf 665 mv.visitVarInsn(ALOAD, 0); // type 666 mv.visitVarInsn(ALOAD, 1); // form 667 // load factory method arguments 668 for (int i = 0, j = 0; i < types.length(); ++i, ++j) { 669 // i counts the arguments, j counts corresponding argument slots 670 char t = types.charAt(i); 671 mv.visitVarInsn(typeLoadOp(t), j + 2); // parameters start at 3 672 if (t == 'J' || t == 'D') { 673 ++j; // adjust argument register access 674 } 675 } 676 677 // finally, invoke the constructor and return 678 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false); 679 mv.visitInsn(ARETURN); 680 mv.visitMaxs(0, 0); 681 mv.visitEnd(); 682 683 // emit copyWith() 684 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null); 685 mv.visitCode(); 686 // make instance 687 mv.visitTypeInsn(NEW, className); 688 mv.visitInsn(DUP); 689 // load mt, lf 690 mv.visitVarInsn(ALOAD, 1); 691 mv.visitVarInsn(ALOAD, 2); 692 // put fields on the stack 693 emitPushFields(types, className, mv); 694 // finally, invoke the constructor and return 695 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false); 696 mv.visitInsn(ARETURN); 697 mv.visitMaxs(0, 0); 698 mv.visitEnd(); 699 700 // for each type, emit copyWithExtendT() 701 for (BasicType type : BasicType.ARG_TYPES) { 702 int ord = type.ordinal(); 703 char btChar = type.basicTypeChar(); 704 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE); 705 mv.visitCode(); 706 // return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg) 707 // obtain constructor 708 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); 709 int iconstInsn = ICONST_0 + ord; 710 assert(iconstInsn <= ICONST_5); 711 mv.visitInsn(iconstInsn); 712 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false); 713 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false); 714 // load mt, lf 715 mv.visitVarInsn(ALOAD, 1); 716 mv.visitVarInsn(ALOAD, 2); 717 // put fields on the stack 718 emitPushFields(types, className, mv); 719 // put narg on stack 720 mv.visitVarInsn(typeLoadOp(btChar), 3); 721 // finally, invoke the constructor and return 722 mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false); 723 mv.visitInsn(ARETURN); 724 mv.visitMaxs(0, 0); 725 mv.visitEnd(); 726 } 727 728 cw.visitEnd(); 729 730 return cw.toByteArray(); 731 } 732 733 private static int typeLoadOp(char t) { 734 switch (t) { 735 case 'L': return ALOAD; 736 case 'I': return ILOAD; 737 case 'J': return LLOAD; 738 case 'F': return FLOAD; 739 case 'D': return DLOAD; 740 default : throw newInternalError("unrecognized type " + t); 741 } 742 } 743 744 private static void emitPushFields(String types, String className, MethodVisitor mv) { 745 for (int i = 0; i < types.length(); ++i) { 746 char tc = types.charAt(i); 747 mv.visitVarInsn(ALOAD, 0); 748 mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc)); 749 } 750 } 751 752 static String typeSig(char t) { 753 return t == 'L' ? JLO_SIG : String.valueOf(t); 754 } 755 756 // 757 // Getter MH generation. 758 // 759 760 private static MethodHandle makeGetter(Class<?> cbmhClass, String types, int index) { 761 String fieldName = makeFieldName(types, index); 762 Class<?> fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType(); 763 try { 764 return LOOKUP.findGetter(cbmhClass, fieldName, fieldType); 765 } catch (NoSuchFieldException | IllegalAccessException e) { 766 throw newInternalError(e); 767 } 768 } 769 770 static MethodHandle[] makeGetters(Class<?> cbmhClass, String types, MethodHandle[] mhs) { 771 if (mhs == null) mhs = new MethodHandle[types.length()]; 772 for (int i = 0; i < mhs.length; ++i) { 773 mhs[i] = makeGetter(cbmhClass, types, i); 774 assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass); 775 } 776 return mhs; 777 } 778 779 static MethodHandle[] makeCtors(Class<? extends BoundMethodHandle> cbmh, String types, MethodHandle mhs[]) { 780 if (mhs == null) mhs = new MethodHandle[1]; 781 if (types.equals("")) return mhs; // hack for empty BMH species 782 mhs[0] = makeCbmhCtor(cbmh, types); 783 return mhs; 784 } 785 786 static NamedFunction[] makeNominalGetters(String types, NamedFunction[] nfs, MethodHandle[] getters) { 787 if (nfs == null) nfs = new NamedFunction[types.length()]; 788 for (int i = 0; i < nfs.length; ++i) { 789 nfs[i] = new NamedFunction(getters[i]); 790 } 791 return nfs; 792 } 793 794 // 795 // Auxiliary methods. 796 // 797 798 static SpeciesData getSpeciesDataFromConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh) { 799 try { 800 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA"); 801 return (SpeciesData) F_SPECIES_DATA.get(null); 802 } catch (ReflectiveOperationException ex) { 803 throw newInternalError(ex); 804 } 805 } 806 807 static void setSpeciesDataToConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh, SpeciesData speciesData) { 808 try { 809 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA"); 810 // ## FIXME: annotation parser can't create proxy classes until module system is fully initialzed 811 // assert F_SPECIES_DATA.getDeclaredAnnotation(Stable.class) != null; 812 F_SPECIES_DATA.set(null, speciesData); 813 } catch (ReflectiveOperationException ex) { 814 throw newInternalError(ex); 815 } 816 } 817 818 /** 819 * Field names in concrete BMHs adhere to this pattern: 820 * arg + type + index 821 * where type is a single character (L, I, J, F, D). 822 */ 823 private static String makeFieldName(String types, int index) { 824 assert index >= 0 && index < types.length(); 825 return "arg" + types.charAt(index) + index; 826 } 827 828 private static String makeSignature(String types, boolean ctor) { 829 StringBuilder buf = new StringBuilder(SIG_INCIPIT); 830 int len = types.length(); 831 for (int i = 0; i < len; i++) { 832 buf.append(typeSig(types.charAt(i))); 833 } 834 return buf.append(')').append(ctor ? "V" : BMH_SIG).toString(); 835 } 836 837 private static MethodType makeConstructorType(String types) { 838 int length = types.length(); 839 Class<?> ptypes[] = new Class<?>[length + 2]; 840 ptypes[0] = MethodType.class; 841 ptypes[1] = LambdaForm.class; 842 for (int i = 0; i < length; i++) { 843 ptypes[i + 2] = BasicType.basicType(types.charAt(i)).basicTypeClass(); 844 } 845 return MethodType.makeImpl(BoundMethodHandle.class, ptypes, true); 846 } 847 848 static MethodHandle makeCbmhCtor(Class<? extends BoundMethodHandle> cbmh, String types) { 849 try { 850 return LOOKUP.findStatic(cbmh, "make", makeConstructorType(types)); 851 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) { 852 throw newInternalError(e); 853 } 854 } 855 } 856 857 static final Lookup LOOKUP = Lookup.IMPL_LOOKUP; 858 859 /** 860 * All subclasses must provide such a value describing their type signature. 861 */ 862 static final SpeciesData SPECIES_DATA = SpeciesData.EMPTY; 863 864 private static final SpeciesData[] SPECIES_DATA_CACHE = new SpeciesData[6]; 865 private static SpeciesData checkCache(int size, String types) { 866 int idx = size - 1; 867 SpeciesData data = SPECIES_DATA_CACHE[idx]; 868 if (data != null) return data; 869 SPECIES_DATA_CACHE[idx] = data = getSpeciesData(types); 870 return data; 871 } 872 static SpeciesData speciesData_L() { return checkCache(1, "L"); } 873 static SpeciesData speciesData_LL() { return checkCache(2, "LL"); } 874 static SpeciesData speciesData_LLL() { return checkCache(3, "LLL"); } 875 static SpeciesData speciesData_LLLL() { return checkCache(4, "LLLL"); } 876 static SpeciesData speciesData_LLLLL() { return checkCache(5, "LLLLL"); } 877} 878