1 /* 2 * Copyright (c) 2008, 2015, 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.vm.annotation.Stable; 30 import jdk.internal.org.objectweb.asm.ClassWriter; 31 import jdk.internal.org.objectweb.asm.FieldVisitor; 32 import jdk.internal.org.objectweb.asm.MethodVisitor; 33 import sun.invoke.util.ValueConversions; 34 import sun.invoke.util.Wrapper; 35 36 import java.lang.invoke.LambdaForm.NamedFunction; 37 import java.lang.invoke.MethodHandles.Lookup; 38 import java.lang.reflect.Field; 39 import java.util.Arrays; 40 import java.util.concurrent.ConcurrentHashMap; 41 import java.util.concurrent.ConcurrentMap; 42 import java.util.function.Function; 43 44 import static java.lang.invoke.LambdaForm.BasicType; 45 import static java.lang.invoke.LambdaForm.BasicType.*; 46 import static java.lang.invoke.MethodHandleStatics.*; 47 import java.util.Map; 48 import static jdk.internal.org.objectweb.asm.Opcodes.*; 49 50 /** 51 * The flavor of method handle which emulates an invoke instruction 52 * on a predetermined argument. The JVM dispatches to the correct method 53 * when the handle is created, not when it is invoked. 54 * 55 * All bound arguments are encapsulated in dedicated species. 56 */ 57 /*non-public*/ abstract class BoundMethodHandle extends MethodHandle { 58 59 /*non-public*/ BoundMethodHandle(MethodType type, LambdaForm form) { 60 super(type, form); 61 assert(speciesData() == speciesData(form)); 62 } 63 64 // 65 // BMH API and internals 66 // 67 68 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) { 69 // for some type signatures, there exist pre-defined concrete BMH classes 70 try { 71 switch (xtype) { 72 case L_TYPE: 73 return bindSingle(type, form, x); // Use known fast path. 74 case I_TYPE: 75 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(I_TYPE).constructor().invokeBasic(type, form, ValueConversions.widenSubword(x)); 76 case J_TYPE: 77 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(J_TYPE).constructor().invokeBasic(type, form, (long) x); 78 case F_TYPE: 79 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(F_TYPE).constructor().invokeBasic(type, form, (float) x); 80 case D_TYPE: 81 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(D_TYPE).constructor().invokeBasic(type, form, (double) x); 82 default : throw newInternalError("unexpected xtype: " + xtype); 83 } 84 } catch (Throwable t) { 85 throw newInternalError(t); 86 } 87 } 88 89 /*non-public*/ 90 LambdaFormEditor editor() { 91 return form.editor(); 92 } 93 94 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) { 95 return Species_L.make(type, form, x); 96 } 97 98 @Override // there is a default binder in the super class, for 'L' types only 99 /*non-public*/ 100 BoundMethodHandle bindArgumentL(int pos, Object value) { 101 return editor().bindArgumentL(this, pos, value); 102 } 103 /*non-public*/ 104 BoundMethodHandle bindArgumentI(int pos, int value) { 105 return editor().bindArgumentI(this, pos, value); 106 } 107 /*non-public*/ 108 BoundMethodHandle bindArgumentJ(int pos, long value) { 109 return editor().bindArgumentJ(this, pos, value); 110 } 111 /*non-public*/ 112 BoundMethodHandle bindArgumentF(int pos, float value) { 113 return editor().bindArgumentF(this, pos, value); 114 } 115 /*non-public*/ 116 BoundMethodHandle bindArgumentD(int pos, double value) { 117 return editor().bindArgumentD(this, pos, value); 118 } 119 120 @Override 121 BoundMethodHandle rebind() { 122 if (!tooComplex()) { 123 return this; 124 } 125 return makeReinvoker(this); 126 } 127 128 private boolean tooComplex() { 129 return (fieldCount() > FIELD_COUNT_THRESHOLD || 130 form.expressionCount() > FORM_EXPRESSION_THRESHOLD); 131 } 132 private static final int FIELD_COUNT_THRESHOLD = 12; // largest convenient BMH field count 133 private static final int FORM_EXPRESSION_THRESHOLD = 24; // largest convenient BMH expression count 134 135 /** 136 * A reinvoker MH has this form: 137 * {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }} 138 */ 139 static BoundMethodHandle makeReinvoker(MethodHandle target) { 140 LambdaForm form = DelegatingMethodHandle.makeReinvokerForm( 141 target, MethodTypeForm.LF_REBIND, 142 Species_L.SPECIES_DATA, Species_L.SPECIES_DATA.getterFunction(0)); 143 return Species_L.make(target.type(), form, target); 144 } 145 146 /** 147 * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a 148 * static field containing this value, and they must accordingly implement this method. 149 */ 150 /*non-public*/ abstract SpeciesData speciesData(); 151 152 /*non-public*/ static SpeciesData speciesData(LambdaForm form) { 153 Object c = form.names[0].constraint; 154 if (c instanceof SpeciesData) 155 return (SpeciesData) c; 156 // if there is no BMH constraint, then use the null constraint 157 return SpeciesData.EMPTY; 158 } 159 160 /** 161 * Return the number of fields in this BMH. Equivalent to speciesData().fieldCount(). 162 */ 163 /*non-public*/ abstract int fieldCount(); 164 165 @Override 166 Object internalProperties() { 167 return "\n& BMH="+internalValues(); 168 } 169 170 @Override 171 final Object internalValues() { 172 Object[] boundValues = new Object[speciesData().fieldCount()]; 173 for (int i = 0; i < boundValues.length; ++i) { 174 boundValues[i] = arg(i); 175 } 176 return Arrays.asList(boundValues); 177 } 178 179 /*non-public*/ final Object arg(int i) { 180 try { 181 switch (speciesData().fieldType(i)) { 182 case L_TYPE: return speciesData().getters[i].invokeBasic(this); 183 case I_TYPE: return (int) speciesData().getters[i].invokeBasic(this); 184 case J_TYPE: return (long) speciesData().getters[i].invokeBasic(this); 185 case F_TYPE: return (float) speciesData().getters[i].invokeBasic(this); 186 case D_TYPE: return (double) speciesData().getters[i].invokeBasic(this); 187 } 188 } catch (Throwable ex) { 189 throw newInternalError(ex); 190 } 191 throw new InternalError("unexpected type: " + speciesData().typeChars+"."+i); 192 } 193 194 // 195 // cloning API 196 // 197 198 /*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf); 199 /*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg); 200 /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg); 201 /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg); 202 /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg); 203 /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg); 204 205 // 206 // concrete BMH classes required to close bootstrap loops 207 // 208 209 private // make it private to force users to access the enclosing class first 210 static final class Species_L extends BoundMethodHandle { 211 final Object argL0; 212 private Species_L(MethodType mt, LambdaForm lf, Object argL0) { 213 super(mt, lf); 214 this.argL0 = argL0; 215 } 216 @Override 217 /*non-public*/ SpeciesData speciesData() { 218 return SPECIES_DATA; 219 } 220 @Override 221 /*non-public*/ int fieldCount() { 222 return 1; 223 } 224 /*non-public*/ static final SpeciesData SPECIES_DATA = new SpeciesData("L", Species_L.class); 225 /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) { 226 return new Species_L(mt, lf, argL0); 227 } 228 @Override 229 /*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) { 230 return new Species_L(mt, lf, argL0); 231 } 232 @Override 233 /*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) { 234 try { 235 return (BoundMethodHandle) SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 236 } catch (Throwable ex) { 237 throw uncaughtException(ex); 238 } 239 } 240 @Override 241 /*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) { 242 try { 243 return (BoundMethodHandle) SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 244 } catch (Throwable ex) { 245 throw uncaughtException(ex); 246 } 247 } 248 @Override 249 /*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) { 250 try { 251 return (BoundMethodHandle) SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 252 } catch (Throwable ex) { 253 throw uncaughtException(ex); 254 } 255 } 256 @Override 257 /*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) { 258 try { 259 return (BoundMethodHandle) SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 260 } catch (Throwable ex) { 261 throw uncaughtException(ex); 262 } 263 } 264 @Override 265 /*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) { 266 try { 267 return (BoundMethodHandle) SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, narg); 268 } catch (Throwable ex) { 269 throw uncaughtException(ex); 270 } 271 } 272 } 273 274 // 275 // BMH species meta-data 276 // 277 278 /** 279 * Meta-data wrapper for concrete BMH types. 280 * Each BMH type corresponds to a given sequence of basic field types (LIJFD). 281 * The fields are immutable; their values are fully specified at object construction. 282 * Each BMH type supplies an array of getter functions which may be used in lambda forms. 283 * A BMH is constructed by cloning a shorter BMH and adding one or more new field values. 284 * The shortest possible BMH has zero fields; its class is SimpleMethodHandle. 285 * BMH species are not interrelated by subtyping, even though it would appear that 286 * a shorter BMH could serve as a supertype of a longer one which extends it. 287 */ 288 static class SpeciesData { 289 private final String typeChars; 290 private final BasicType[] typeCodes; 291 private final Class<? extends BoundMethodHandle> clazz; 292 // Bootstrapping requires circular relations MH -> BMH -> SpeciesData -> MH 293 // Therefore, we need a non-final link in the chain. Use array elements. 294 @Stable private final MethodHandle[] constructor; 295 @Stable private final MethodHandle[] getters; 296 @Stable private final NamedFunction[] nominalGetters; 297 @Stable private final SpeciesData[] extensions; 298 299 /*non-public*/ int fieldCount() { 300 return typeCodes.length; 301 } 302 /*non-public*/ BasicType fieldType(int i) { 303 return typeCodes[i]; 304 } 305 /*non-public*/ char fieldTypeChar(int i) { 306 return typeChars.charAt(i); 307 } 308 Object fieldSignature() { 309 return typeChars; 310 } 311 public Class<? extends BoundMethodHandle> fieldHolder() { 312 return clazz; 313 } 314 public String toString() { 315 return "SpeciesData<"+fieldSignature()+">"; 316 } 317 318 /** 319 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that 320 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding 321 * getter. 322 */ 323 NamedFunction getterFunction(int i) { 324 NamedFunction nf = nominalGetters[i]; 325 assert(nf.memberDeclaringClassOrNull() == fieldHolder()); 326 assert(nf.returnType() == fieldType(i)); 327 return nf; 328 } 329 330 NamedFunction[] getterFunctions() { 331 return nominalGetters; 332 } 333 334 MethodHandle[] getterHandles() { return getters; } 335 336 MethodHandle constructor() { 337 return constructor[0]; 338 } 339 340 static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class); 341 342 SpeciesData(String types, Class<? extends BoundMethodHandle> clazz) { 343 this.typeChars = types; 344 this.typeCodes = basicTypes(types); 345 this.clazz = clazz; 346 if (!INIT_DONE) { 347 this.constructor = new MethodHandle[1]; // only one ctor 348 this.getters = new MethodHandle[types.length()]; 349 this.nominalGetters = new NamedFunction[types.length()]; 350 } else { 351 this.constructor = Factory.makeCtors(clazz, types, null); 352 this.getters = Factory.makeGetters(clazz, types, null); 353 this.nominalGetters = Factory.makeNominalGetters(types, null, this.getters); 354 } 355 this.extensions = new SpeciesData[ARG_TYPE_LIMIT]; 356 } 357 358 private void initForBootstrap() { 359 assert(!INIT_DONE); 360 if (constructor() == null) { 361 String types = typeChars; 362 CACHE.put(types, this); 363 Factory.makeCtors(clazz, types, this.constructor); 364 Factory.makeGetters(clazz, types, this.getters); 365 Factory.makeNominalGetters(types, this.nominalGetters, this.getters); 366 } 367 } 368 369 private static final ConcurrentMap<String, SpeciesData> CACHE = new ConcurrentHashMap<>(); 370 private static final boolean INIT_DONE; // set after <clinit> finishes... 371 372 SpeciesData extendWith(byte type) { 373 return extendWith(BasicType.basicType(type)); 374 } 375 376 SpeciesData extendWith(BasicType type) { 377 int ord = type.ordinal(); 378 SpeciesData d = extensions[ord]; 379 if (d != null) return d; 380 extensions[ord] = d = get(typeChars+type.basicTypeChar()); 381 return d; 382 } 383 384 private static SpeciesData get(String types) { 385 return CACHE.computeIfAbsent(types, new Function<String, SpeciesData>() { 386 @Override 387 public SpeciesData apply(String types) { 388 Class<? extends BoundMethodHandle> bmhcl = Factory.getConcreteBMHClass(types); 389 // SpeciesData instantiation may throw VirtualMachineError because of 390 // code cache overflow... 391 SpeciesData speciesData = new SpeciesData(types, bmhcl); 392 // CHM.computeIfAbsent ensures only one SpeciesData will be set 393 // successfully on the concrete BMH class if ever 394 Factory.setSpeciesDataToConcreteBMHClass(bmhcl, speciesData); 395 // the concrete BMH class is published via SpeciesData instance 396 // returned here only after it's SPECIES_DATA field is set 397 return speciesData; 398 } 399 }); 400 } 401 402 /** 403 * This is to be called when assertions are enabled. It checks whether SpeciesData for all of the statically 404 * defined species subclasses of BoundMethodHandle has been added to the SpeciesData cache. See below in the 405 * static initializer for 406 */ 407 static boolean speciesDataCachePopulated() { 408 Class<BoundMethodHandle> rootCls = BoundMethodHandle.class; 409 try { 410 for (Class<?> c : rootCls.getDeclaredClasses()) { 411 if (rootCls.isAssignableFrom(c)) { 412 final Class<? extends BoundMethodHandle> cbmh = c.asSubclass(BoundMethodHandle.class); 413 SpeciesData d = Factory.getSpeciesDataFromConcreteBMHClass(cbmh); 414 assert(d != null) : cbmh.getName(); 415 assert(d.clazz == cbmh); 416 assert(CACHE.get(d.typeChars) == d); 417 } 418 } 419 } catch (Throwable e) { 420 throw newInternalError(e); 421 } 422 return true; 423 } 424 425 static { 426 // Pre-fill the BMH species-data cache with EMPTY and all BMH's inner subclasses. 427 EMPTY.initForBootstrap(); 428 Species_L.SPECIES_DATA.initForBootstrap(); 429 // check that all static SpeciesData instances have been initialized 430 assert speciesDataCachePopulated(); 431 // Note: Do not simplify this, because INIT_DONE must not be 432 // a compile-time constant during bootstrapping. 433 INIT_DONE = Boolean.TRUE; 434 } 435 } 436 437 static SpeciesData getSpeciesData(String types) { 438 return SpeciesData.get(types); 439 } 440 441 /** 442 * Generation of concrete BMH classes. 443 * 444 * A concrete BMH species is fit for binding a number of values adhering to a 445 * given type pattern. Reference types are erased. 446 * 447 * BMH species are cached by type pattern. 448 * 449 * A BMH species has a number of fields with the concrete (possibly erased) types of 450 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs, 451 * which can be included as names in lambda forms. 452 */ 453 static class Factory { 454 455 static final String JLO_SIG = "Ljava/lang/Object;"; 456 static final String JLS_SIG = "Ljava/lang/String;"; 457 static final String JLC_SIG = "Ljava/lang/Class;"; 458 static final String MH = "java/lang/invoke/MethodHandle"; 459 static final String MH_SIG = "L"+MH+";"; 460 static final String BMH = "java/lang/invoke/BoundMethodHandle"; 461 static final String BMH_SIG = "L"+BMH+";"; 462 static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData"; 463 static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";"; 464 static final String STABLE_SIG = "Ljdk/internal/vm/annotation/Stable;"; 465 466 static final String SPECIES_PREFIX_NAME = "Species_"; 467 static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME; 468 469 static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG; 470 static final String BMHSPECIES_DATA_GFC_SIG = "(" + JLS_SIG + JLC_SIG + ")" + SPECIES_DATA_SIG; 471 static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG; 472 static final String VOID_SIG = "()V"; 473 static final String INT_SIG = "()I"; 474 475 static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;"; 476 477 static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" }; 478 479 static final ConcurrentMap<String, Class<? extends BoundMethodHandle>> CLASS_CACHE = new ConcurrentHashMap<>(); 480 481 /** 482 * Get a concrete subclass of BMH for a given combination of bound types. 483 * 484 * @param types the type signature, wherein reference types are erased to 'L' 485 * @return the concrete BMH class 486 */ 487 static Class<? extends BoundMethodHandle> getConcreteBMHClass(String types) { 488 // CHM.computeIfAbsent ensures generateConcreteBMHClass is called 489 // only once per key. 490 return CLASS_CACHE.computeIfAbsent( 491 types, new Function<String, Class<? extends BoundMethodHandle>>() { 492 @Override 493 public Class<? extends BoundMethodHandle> apply(String types) { 494 String name = "java.lang.invoke.BoundMethodHandle$Species_" 495 + LambdaForm.shortenSignature(types); 496 Class<?> c = BootLoader.loadClassOrNull(name); 497 if (c != null) { 498 return c.asSubclass(BoundMethodHandle.class); 499 } else { 500 // Not pregenerated, generate the class 501 return generateConcreteBMHClass(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 types) { 572 Map.Entry<String, byte[]> result = generateConcreteBMHClassBytes(types); 573 String className = result.getKey(); 574 byte[] classFile = result.getValue(); 575 576 // load class 577 InvokerBytecodeGenerator.maybeDump(className, classFile); 578 Class<? extends BoundMethodHandle> bmhClass = 579 //UNSAFE.defineAnonymousClass(BoundMethodHandle.class, classFile, null).asSubclass(BoundMethodHandle.class); 580 UNSAFE.defineClass(className, classFile, 0, classFile.length, 581 BoundMethodHandle.class.getClassLoader(), null) 582 .asSubclass(BoundMethodHandle.class); 583 584 return bmhClass; 585 } 586 587 static Map.Entry<String, byte[]> generateConcreteBMHClassBytes(final String types) { 588 String shortTypes = LambdaForm.shortenSignature(types); 589 final String className = SPECIES_PREFIX_PATH + shortTypes; 590 final String sourceFile = SPECIES_PREFIX_NAME + shortTypes; 591 592 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 593 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC 594 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null); 595 cw.visitSource(sourceFile, null); 596 // emit static types and SPECIES_DATA fields 597 FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null); 598 fw.visitAnnotation(STABLE_SIG, true); 599 fw.visitEnd(); 600 // emit bound argument fields 601 for (int i = 0; i < types.length(); ++i) { 602 final char t = types.charAt(i); 603 final String fieldName = makeFieldName(types, i); 604 final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t); 605 cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd(); 606 } 607 MethodVisitor mv; 608 // emit constructor 609 mv = cw.visitMethod(ACC_PRIVATE, "<init>", makeSignature(types, true), null, null); 610 mv.visitCode(); 611 mv.visitVarInsn(ALOAD, 0); // this 612 mv.visitVarInsn(ALOAD, 1); // type 613 mv.visitVarInsn(ALOAD, 2); // form 614 mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false); 615 for (int i = 0, j = 0; i < types.length(); ++i, ++j) { 616 // i counts the arguments, j counts corresponding argument slots 617 char t = types.charAt(i); 618 mv.visitVarInsn(ALOAD, 0); 619 mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3 620 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t)); 621 if (t == 'J' || t == 'D') { 622 ++j; // adjust argument register access 623 } 624 } 625 mv.visitInsn(RETURN); 626 mv.visitMaxs(0, 0); 627 mv.visitEnd(); 628 // emit implementation of speciesData() 629 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null); 630 mv.visitCode(); 631 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); 632 mv.visitInsn(ARETURN); 633 mv.visitMaxs(0, 0); 634 mv.visitEnd(); 635 // emit implementation of fieldCount() 636 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null); 637 mv.visitCode(); 638 int fc = types.length(); 639 if (fc <= (ICONST_5 - ICONST_0)) { 640 mv.visitInsn(ICONST_0 + fc); 641 } else { 642 mv.visitIntInsn(SIPUSH, fc); 643 } 644 mv.visitInsn(IRETURN); 645 mv.visitMaxs(0, 0); 646 mv.visitEnd(); 647 // emit make() ...factory method wrapping constructor 648 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null); 649 mv.visitCode(); 650 // make instance 651 mv.visitTypeInsn(NEW, className); 652 mv.visitInsn(DUP); 653 // load mt, lf 654 mv.visitVarInsn(ALOAD, 0); // type 655 mv.visitVarInsn(ALOAD, 1); // form 656 // load factory method arguments 657 for (int i = 0, j = 0; i < types.length(); ++i, ++j) { 658 // i counts the arguments, j counts corresponding argument slots 659 char t = types.charAt(i); 660 mv.visitVarInsn(typeLoadOp(t), j + 2); // parameters start at 3 661 if (t == 'J' || t == 'D') { 662 ++j; // adjust argument register access 663 } 664 } 665 // finally, invoke the constructor and return 666 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false); 667 mv.visitInsn(ARETURN); 668 mv.visitMaxs(0, 0); 669 mv.visitEnd(); 670 // emit copyWith() 671 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null); 672 mv.visitCode(); 673 // make instance 674 mv.visitTypeInsn(NEW, className); 675 mv.visitInsn(DUP); 676 // load mt, lf 677 mv.visitVarInsn(ALOAD, 1); 678 mv.visitVarInsn(ALOAD, 2); 679 // put fields on the stack 680 emitPushFields(types, className, mv); 681 // finally, invoke the constructor and return 682 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false); 683 mv.visitInsn(ARETURN); 684 mv.visitMaxs(0, 0); 685 mv.visitEnd(); 686 // for each type, emit copyWithExtendT() 687 for (BasicType type : BasicType.ARG_TYPES) { 688 int ord = type.ordinal(); 689 char btChar = type.basicTypeChar(); 690 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE); 691 mv.visitCode(); 692 // return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg) 693 // obtain constructor 694 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); 695 int iconstInsn = ICONST_0 + ord; 696 assert(iconstInsn <= ICONST_5); 697 mv.visitInsn(iconstInsn); 698 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false); 699 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false); 700 // load mt, lf 701 mv.visitVarInsn(ALOAD, 1); 702 mv.visitVarInsn(ALOAD, 2); 703 // put fields on the stack 704 emitPushFields(types, className, mv); 705 // put narg on stack 706 mv.visitVarInsn(typeLoadOp(btChar), 3); 707 // finally, invoke the constructor and return 708 mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false); 709 mv.visitInsn(ARETURN); 710 mv.visitMaxs(0, 0); 711 mv.visitEnd(); 712 } 713 cw.visitEnd(); 714 return Map.entry(className, cw.toByteArray()); 715 } 716 717 private static int typeLoadOp(char t) { 718 switch (t) { 719 case 'L': return ALOAD; 720 case 'I': return ILOAD; 721 case 'J': return LLOAD; 722 case 'F': return FLOAD; 723 case 'D': return DLOAD; 724 default : throw newInternalError("unrecognized type " + t); 725 } 726 } 727 728 private static void emitPushFields(String types, String className, MethodVisitor mv) { 729 for (int i = 0; i < types.length(); ++i) { 730 char tc = types.charAt(i); 731 mv.visitVarInsn(ALOAD, 0); 732 mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc)); 733 } 734 } 735 736 static String typeSig(char t) { 737 return t == 'L' ? JLO_SIG : String.valueOf(t); 738 } 739 740 // 741 // Getter MH generation. 742 // 743 744 private static MethodHandle makeGetter(Class<?> cbmhClass, String types, int index) { 745 String fieldName = makeFieldName(types, index); 746 Class<?> fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType(); 747 try { 748 return LOOKUP.findGetter(cbmhClass, fieldName, fieldType); 749 } catch (NoSuchFieldException | IllegalAccessException e) { 750 throw newInternalError(e); 751 } 752 } 753 754 static MethodHandle[] makeGetters(Class<?> cbmhClass, String types, MethodHandle[] mhs) { 755 if (mhs == null) mhs = new MethodHandle[types.length()]; 756 for (int i = 0; i < mhs.length; ++i) { 757 mhs[i] = makeGetter(cbmhClass, types, i); 758 assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass); 759 } 760 return mhs; 761 } 762 763 static MethodHandle[] makeCtors(Class<? extends BoundMethodHandle> cbmh, String types, MethodHandle mhs[]) { 764 if (mhs == null) mhs = new MethodHandle[1]; 765 if (types.equals("")) return mhs; // hack for empty BMH species 766 mhs[0] = makeCbmhCtor(cbmh, types); 767 return mhs; 768 } 769 770 static NamedFunction[] makeNominalGetters(String types, NamedFunction[] nfs, MethodHandle[] getters) { 771 if (nfs == null) nfs = new NamedFunction[types.length()]; 772 for (int i = 0; i < nfs.length; ++i) { 773 nfs[i] = new NamedFunction(getters[i]); 774 } 775 return nfs; 776 } 777 778 // 779 // Auxiliary methods. 780 // 781 782 static SpeciesData getSpeciesDataFromConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh) { 783 try { 784 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA"); 785 return (SpeciesData) F_SPECIES_DATA.get(null); 786 } catch (ReflectiveOperationException ex) { 787 throw newInternalError(ex); 788 } 789 } 790 791 static void setSpeciesDataToConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh, SpeciesData speciesData) { 792 try { 793 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA"); 794 // ## FIXME: annotation parser can't create proxy classes until module system is fully initialzed 795 // assert F_SPECIES_DATA.getDeclaredAnnotation(Stable.class) != null; 796 F_SPECIES_DATA.set(null, speciesData); 797 } catch (ReflectiveOperationException ex) { 798 throw newInternalError(ex); 799 } 800 } 801 802 /** 803 * Field names in concrete BMHs adhere to this pattern: 804 * arg + type + index 805 * where type is a single character (L, I, J, F, D). 806 */ 807 private static String makeFieldName(String types, int index) { 808 assert index >= 0 && index < types.length(); 809 return "arg" + types.charAt(index) + index; 810 } 811 812 private static String makeSignature(String types, boolean ctor) { 813 StringBuilder buf = new StringBuilder(SIG_INCIPIT); 814 for (char c : types.toCharArray()) { 815 buf.append(typeSig(c)); 816 } 817 return buf.append(')').append(ctor ? "V" : BMH_SIG).toString(); 818 } 819 820 static MethodHandle makeCbmhCtor(Class<? extends BoundMethodHandle> cbmh, String types) { 821 try { 822 return LOOKUP.findStatic(cbmh, "make", MethodType.fromDescriptor(makeSignature(types, false), null)); 823 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) { 824 throw newInternalError(e); 825 } 826 } 827 } 828 829 private static final Lookup LOOKUP = Lookup.IMPL_LOOKUP; 830 831 /** 832 * All subclasses must provide such a value describing their type signature. 833 */ 834 static final SpeciesData SPECIES_DATA = SpeciesData.EMPTY; 835 836 private static final SpeciesData[] SPECIES_DATA_CACHE = new SpeciesData[5]; 837 private static SpeciesData checkCache(int size, String types) { 838 int idx = size - 1; 839 SpeciesData data = SPECIES_DATA_CACHE[idx]; 840 if (data != null) return data; 841 SPECIES_DATA_CACHE[idx] = data = getSpeciesData(types); 842 return data; 843 } 844 static SpeciesData speciesData_L() { return checkCache(1, "L"); } 845 static SpeciesData speciesData_LL() { return checkCache(2, "LL"); } 846 static SpeciesData speciesData_LLL() { return checkCache(3, "LLL"); } 847 static SpeciesData speciesData_LLLL() { return checkCache(4, "LLLL"); } 848 static SpeciesData speciesData_LLLLL() { return checkCache(5, "LLLLL"); } 849 }