1 /* 2 * Copyright (c) 2008, 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.misc.JavaLangInvokeAccess; 29 import jdk.internal.misc.SharedSecrets; 30 import jdk.internal.org.objectweb.asm.AnnotationVisitor; 31 import jdk.internal.org.objectweb.asm.ClassWriter; 32 import jdk.internal.org.objectweb.asm.MethodVisitor; 33 import jdk.internal.reflect.CallerSensitive; 34 import jdk.internal.reflect.Reflection; 35 import jdk.internal.vm.annotation.ForceInline; 36 import jdk.internal.vm.annotation.Stable; 37 import sun.invoke.empty.Empty; 38 import sun.invoke.util.ValueConversions; 39 import sun.invoke.util.VerifyType; 40 import sun.invoke.util.Wrapper; 41 42 import java.lang.reflect.Array; 43 import java.util.Arrays; 44 import java.util.Collections; 45 import java.util.Iterator; 46 import java.util.List; 47 import java.util.Map; 48 import java.util.function.Function; 49 import java.util.stream.Stream; 50 51 import static java.lang.invoke.LambdaForm.*; 52 import static java.lang.invoke.MethodHandleStatics.*; 53 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP; 54 import static jdk.internal.org.objectweb.asm.Opcodes.*; 55 56 /** 57 * Trusted implementation code for MethodHandle. 58 * @author jrose 59 */ 60 /*non-public*/ abstract class MethodHandleImpl { 61 62 /// Factory methods to create method handles: 63 64 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, ArrayAccess access) { 65 if (arrayClass == Object[].class) { 66 return ArrayAccess.objectAccessor(access); 67 } 68 if (!arrayClass.isArray()) 69 throw newIllegalArgumentException("not an array: "+arrayClass); 70 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass); 71 int cacheIndex = ArrayAccess.cacheIndex(access); 72 MethodHandle mh = cache[cacheIndex]; 73 if (mh != null) return mh; 74 mh = ArrayAccessor.getAccessor(arrayClass, access); 75 MethodType correctType = ArrayAccessor.correctType(arrayClass, access); 76 if (mh.type() != correctType) { 77 assert(mh.type().parameterType(0) == Object[].class); 78 /* if access == SET */ assert(access != ArrayAccess.SET || mh.type().parameterType(2) == Object.class); 79 /* if access == GET */ assert(access != ArrayAccess.GET || 80 (mh.type().returnType() == Object.class && 81 correctType.parameterType(0).getComponentType() == correctType.returnType())); 82 // safe to view non-strictly, because element type follows from array type 83 mh = mh.viewAsType(correctType, false); 84 } 85 mh = makeIntrinsic(mh, ArrayAccess.intrinsic(access)); 86 // Atomically update accessor cache. 87 synchronized(cache) { 88 if (cache[cacheIndex] == null) { 89 cache[cacheIndex] = mh; 90 } else { 91 // Throw away newly constructed accessor and use cached version. 92 mh = cache[cacheIndex]; 93 } 94 } 95 return mh; 96 } 97 98 enum ArrayAccess { 99 GET, SET, LENGTH; 100 101 // As ArrayAccess and ArrayAccessor have a circular dependency, the ArrayAccess properties cannot be stored in 102 // final fields. 103 104 static String opName(ArrayAccess a) { 105 switch (a) { 106 case GET: return "getElement"; 107 case SET: return "setElement"; 108 case LENGTH: return "length"; 109 } 110 throw unmatchedArrayAccess(a); 111 } 112 113 static MethodHandle objectAccessor(ArrayAccess a) { 114 switch (a) { 115 case GET: return ArrayAccessor.OBJECT_ARRAY_GETTER; 116 case SET: return ArrayAccessor.OBJECT_ARRAY_SETTER; 117 case LENGTH: return ArrayAccessor.OBJECT_ARRAY_LENGTH; 118 } 119 throw unmatchedArrayAccess(a); 120 } 121 122 static int cacheIndex(ArrayAccess a) { 123 switch (a) { 124 case GET: return ArrayAccessor.GETTER_INDEX; 125 case SET: return ArrayAccessor.SETTER_INDEX; 126 case LENGTH: return ArrayAccessor.LENGTH_INDEX; 127 } 128 throw unmatchedArrayAccess(a); 129 } 130 131 static Intrinsic intrinsic(ArrayAccess a) { 132 switch (a) { 133 case GET: return Intrinsic.ARRAY_LOAD; 134 case SET: return Intrinsic.ARRAY_STORE; 135 case LENGTH: return Intrinsic.ARRAY_LENGTH; 136 } 137 throw unmatchedArrayAccess(a); 138 } 139 } 140 141 static InternalError unmatchedArrayAccess(ArrayAccess a) { 142 return newInternalError("should not reach here (unmatched ArrayAccess: " + a + ")"); 143 } 144 145 static final class ArrayAccessor { 146 /// Support for array element and length access 147 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, LENGTH_INDEX = 2, INDEX_LIMIT = 3; 148 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS 149 = new ClassValue<MethodHandle[]>() { 150 @Override 151 protected MethodHandle[] computeValue(Class<?> type) { 152 return new MethodHandle[INDEX_LIMIT]; 153 } 154 }; 155 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER, OBJECT_ARRAY_LENGTH; 156 static { 157 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class); 158 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.GET), Intrinsic.ARRAY_LOAD); 159 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.SET), Intrinsic.ARRAY_STORE); 160 cache[LENGTH_INDEX] = OBJECT_ARRAY_LENGTH = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.LENGTH), Intrinsic.ARRAY_LENGTH); 161 162 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName())); 163 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName())); 164 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_LENGTH.internalMemberName())); 165 } 166 167 static int getElementI(int[] a, int i) { return a[i]; } 168 static long getElementJ(long[] a, int i) { return a[i]; } 169 static float getElementF(float[] a, int i) { return a[i]; } 170 static double getElementD(double[] a, int i) { return a[i]; } 171 static boolean getElementZ(boolean[] a, int i) { return a[i]; } 172 static byte getElementB(byte[] a, int i) { return a[i]; } 173 static short getElementS(short[] a, int i) { return a[i]; } 174 static char getElementC(char[] a, int i) { return a[i]; } 175 static Object getElementL(Object[] a, int i) { return a[i]; } 176 177 static void setElementI(int[] a, int i, int x) { a[i] = x; } 178 static void setElementJ(long[] a, int i, long x) { a[i] = x; } 179 static void setElementF(float[] a, int i, float x) { a[i] = x; } 180 static void setElementD(double[] a, int i, double x) { a[i] = x; } 181 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; } 182 static void setElementB(byte[] a, int i, byte x) { a[i] = x; } 183 static void setElementS(short[] a, int i, short x) { a[i] = x; } 184 static void setElementC(char[] a, int i, char x) { a[i] = x; } 185 static void setElementL(Object[] a, int i, Object x) { a[i] = x; } 186 187 static int lengthI(int[] a) { return a.length; } 188 static int lengthJ(long[] a) { return a.length; } 189 static int lengthF(float[] a) { return a.length; } 190 static int lengthD(double[] a) { return a.length; } 191 static int lengthZ(boolean[] a) { return a.length; } 192 static int lengthB(byte[] a) { return a.length; } 193 static int lengthS(short[] a) { return a.length; } 194 static int lengthC(char[] a) { return a.length; } 195 static int lengthL(Object[] a) { return a.length; } 196 197 static String name(Class<?> arrayClass, ArrayAccess access) { 198 Class<?> elemClass = arrayClass.getComponentType(); 199 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass); 200 return ArrayAccess.opName(access) + Wrapper.basicTypeChar(elemClass); 201 } 202 static MethodType type(Class<?> arrayClass, ArrayAccess access) { 203 Class<?> elemClass = arrayClass.getComponentType(); 204 Class<?> arrayArgClass = arrayClass; 205 if (!elemClass.isPrimitive()) { 206 arrayArgClass = Object[].class; 207 elemClass = Object.class; 208 } 209 switch (access) { 210 case GET: return MethodType.methodType(elemClass, arrayArgClass, int.class); 211 case SET: return MethodType.methodType(void.class, arrayArgClass, int.class, elemClass); 212 case LENGTH: return MethodType.methodType(int.class, arrayArgClass); 213 } 214 throw unmatchedArrayAccess(access); 215 } 216 static MethodType correctType(Class<?> arrayClass, ArrayAccess access) { 217 Class<?> elemClass = arrayClass.getComponentType(); 218 switch (access) { 219 case GET: return MethodType.methodType(elemClass, arrayClass, int.class); 220 case SET: return MethodType.methodType(void.class, arrayClass, int.class, elemClass); 221 case LENGTH: return MethodType.methodType(int.class, arrayClass); 222 } 223 throw unmatchedArrayAccess(access); 224 } 225 static MethodHandle getAccessor(Class<?> arrayClass, ArrayAccess access) { 226 String name = name(arrayClass, access); 227 MethodType type = type(arrayClass, access); 228 try { 229 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type); 230 } catch (ReflectiveOperationException ex) { 231 throw uncaughtException(ex); 232 } 233 } 234 } 235 236 /** 237 * Create a JVM-level adapter method handle to conform the given method 238 * handle to the similar newType, using only pairwise argument conversions. 239 * For each argument, convert incoming argument to the exact type needed. 240 * The argument conversions allowed are casting, boxing and unboxing, 241 * integral widening or narrowing, and floating point widening or narrowing. 242 * @param srcType required call type 243 * @param target original method handle 244 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed 245 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double) 246 * @return an adapter to the original handle with the desired new type, 247 * or the original target if the types are already identical 248 * or null if the adaptation cannot be made 249 */ 250 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType, 251 boolean strict, boolean monobox) { 252 MethodType dstType = target.type(); 253 if (srcType == dstType) 254 return target; 255 return makePairwiseConvertByEditor(target, srcType, strict, monobox); 256 } 257 258 private static int countNonNull(Object[] array) { 259 int count = 0; 260 for (Object x : array) { 261 if (x != null) ++count; 262 } 263 return count; 264 } 265 266 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType, 267 boolean strict, boolean monobox) { 268 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox); 269 int convCount = countNonNull(convSpecs); 270 if (convCount == 0) 271 return target.viewAsType(srcType, strict); 272 MethodType basicSrcType = srcType.basicType(); 273 MethodType midType = target.type().basicType(); 274 BoundMethodHandle mh = target.rebind(); 275 // FIXME: Reduce number of bindings when there is more than one Class conversion. 276 // FIXME: Reduce number of bindings when there are repeated conversions. 277 for (int i = 0; i < convSpecs.length-1; i++) { 278 Object convSpec = convSpecs[i]; 279 if (convSpec == null) continue; 280 MethodHandle fn; 281 if (convSpec instanceof Class) { 282 fn = getConstantHandle(MH_cast).bindTo(convSpec); 283 } else { 284 fn = (MethodHandle) convSpec; 285 } 286 Class<?> newType = basicSrcType.parameterType(i); 287 if (--convCount == 0) 288 midType = srcType; 289 else 290 midType = midType.changeParameterType(i, newType); 291 LambdaForm form2 = mh.editor().filterArgumentForm(1+i, BasicType.basicType(newType)); 292 mh = mh.copyWithExtendL(midType, form2, fn); 293 mh = mh.rebind(); 294 } 295 Object convSpec = convSpecs[convSpecs.length-1]; 296 if (convSpec != null) { 297 MethodHandle fn; 298 if (convSpec instanceof Class) { 299 if (convSpec == void.class) 300 fn = null; 301 else 302 fn = getConstantHandle(MH_cast).bindTo(convSpec); 303 } else { 304 fn = (MethodHandle) convSpec; 305 } 306 Class<?> newType = basicSrcType.returnType(); 307 assert(--convCount == 0); 308 midType = srcType; 309 if (fn != null) { 310 mh = mh.rebind(); // rebind if too complex 311 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false); 312 mh = mh.copyWithExtendL(midType, form2, fn); 313 } else { 314 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true); 315 mh = mh.copyWith(midType, form2); 316 } 317 } 318 assert(convCount == 0); 319 assert(mh.type().equals(srcType)); 320 return mh; 321 } 322 323 static MethodHandle makePairwiseConvertIndirect(MethodHandle target, MethodType srcType, 324 boolean strict, boolean monobox) { 325 assert(target.type().parameterCount() == srcType.parameterCount()); 326 // Calculate extra arguments (temporaries) required in the names array. 327 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox); 328 final int INARG_COUNT = srcType.parameterCount(); 329 int convCount = countNonNull(convSpecs); 330 boolean retConv = (convSpecs[INARG_COUNT] != null); 331 boolean retVoid = srcType.returnType() == void.class; 332 if (retConv && retVoid) { 333 convCount -= 1; 334 retConv = false; 335 } 336 337 final int IN_MH = 0; 338 final int INARG_BASE = 1; 339 final int INARG_LIMIT = INARG_BASE + INARG_COUNT; 340 final int NAME_LIMIT = INARG_LIMIT + convCount + 1; 341 final int RETURN_CONV = (!retConv ? -1 : NAME_LIMIT - 1); 342 final int OUT_CALL = (!retConv ? NAME_LIMIT : RETURN_CONV) - 1; 343 final int RESULT = (retVoid ? -1 : NAME_LIMIT - 1); 344 345 // Now build a LambdaForm. 346 MethodType lambdaType = srcType.basicType().invokerType(); 347 Name[] names = arguments(NAME_LIMIT - INARG_LIMIT, lambdaType); 348 349 // Collect the arguments to the outgoing call, maybe with conversions: 350 final int OUTARG_BASE = 0; // target MH is Name.function, name Name.arguments[0] 351 Object[] outArgs = new Object[OUTARG_BASE + INARG_COUNT]; 352 353 int nameCursor = INARG_LIMIT; 354 for (int i = 0; i < INARG_COUNT; i++) { 355 Object convSpec = convSpecs[i]; 356 if (convSpec == null) { 357 // do nothing: difference is trivial 358 outArgs[OUTARG_BASE + i] = names[INARG_BASE + i]; 359 continue; 360 } 361 362 Name conv; 363 if (convSpec instanceof Class) { 364 Class<?> convClass = (Class<?>) convSpec; 365 conv = new Name(getConstantHandle(MH_cast), convClass, names[INARG_BASE + i]); 366 } else { 367 MethodHandle fn = (MethodHandle) convSpec; 368 conv = new Name(fn, names[INARG_BASE + i]); 369 } 370 assert(names[nameCursor] == null); 371 names[nameCursor++] = conv; 372 assert(outArgs[OUTARG_BASE + i] == null); 373 outArgs[OUTARG_BASE + i] = conv; 374 } 375 376 // Build argument array for the call. 377 assert(nameCursor == OUT_CALL); 378 names[OUT_CALL] = new Name(target, outArgs); 379 380 Object convSpec = convSpecs[INARG_COUNT]; 381 if (!retConv) { 382 assert(OUT_CALL == names.length-1); 383 } else { 384 Name conv; 385 if (convSpec == void.class) { 386 conv = new Name(LambdaForm.constantZero(BasicType.basicType(srcType.returnType()))); 387 } else if (convSpec instanceof Class) { 388 Class<?> convClass = (Class<?>) convSpec; 389 conv = new Name(getConstantHandle(MH_cast), convClass, names[OUT_CALL]); 390 } else { 391 MethodHandle fn = (MethodHandle) convSpec; 392 if (fn.type().parameterCount() == 0) 393 conv = new Name(fn); // don't pass retval to void conversion 394 else 395 conv = new Name(fn, names[OUT_CALL]); 396 } 397 assert(names[RETURN_CONV] == null); 398 names[RETURN_CONV] = conv; 399 assert(RETURN_CONV == names.length-1); 400 } 401 402 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, RESULT, Kind.CONVERT); 403 return SimpleMethodHandle.make(srcType, form); 404 } 405 406 static Object[] computeValueConversions(MethodType srcType, MethodType dstType, 407 boolean strict, boolean monobox) { 408 final int INARG_COUNT = srcType.parameterCount(); 409 Object[] convSpecs = new Object[INARG_COUNT+1]; 410 for (int i = 0; i <= INARG_COUNT; i++) { 411 boolean isRet = (i == INARG_COUNT); 412 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i); 413 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i); 414 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) { 415 convSpecs[i] = valueConversion(src, dst, strict, monobox); 416 } 417 } 418 return convSpecs; 419 } 420 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType, 421 boolean strict) { 422 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false); 423 } 424 425 /** 426 * Find a conversion function from the given source to the given destination. 427 * This conversion function will be used as a LF NamedFunction. 428 * Return a Class object if a simple cast is needed. 429 * Return void.class if void is involved. 430 */ 431 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) { 432 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility 433 if (dst == void.class) 434 return dst; 435 MethodHandle fn; 436 if (src.isPrimitive()) { 437 if (src == void.class) { 438 return void.class; // caller must recognize this specially 439 } else if (dst.isPrimitive()) { 440 // Examples: int->byte, byte->int, boolean->int (!strict) 441 fn = ValueConversions.convertPrimitive(src, dst); 442 } else { 443 // Examples: int->Integer, boolean->Object, float->Number 444 Wrapper wsrc = Wrapper.forPrimitiveType(src); 445 fn = ValueConversions.boxExact(wsrc); 446 assert(fn.type().parameterType(0) == wsrc.primitiveType()); 447 assert(fn.type().returnType() == wsrc.wrapperType()); 448 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) { 449 // Corner case, such as int->Long, which will probably fail. 450 MethodType mt = MethodType.methodType(dst, src); 451 if (strict) 452 fn = fn.asType(mt); 453 else 454 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false); 455 } 456 } 457 } else if (dst.isPrimitive()) { 458 Wrapper wdst = Wrapper.forPrimitiveType(dst); 459 if (monobox || src == wdst.wrapperType()) { 460 // Use a strongly-typed unboxer, if possible. 461 fn = ValueConversions.unboxExact(wdst, strict); 462 } else { 463 // Examples: Object->int, Number->int, Comparable->int, Byte->int 464 // must include additional conversions 465 // src must be examined at runtime, to detect Byte, Character, etc. 466 fn = (strict 467 ? ValueConversions.unboxWiden(wdst) 468 : ValueConversions.unboxCast(wdst)); 469 } 470 } else { 471 // Simple reference conversion. 472 // Note: Do not check for a class hierarchy relation 473 // between src and dst. In all cases a 'null' argument 474 // will pass the cast conversion. 475 return dst; 476 } 477 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn); 478 return fn; 479 } 480 481 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) { 482 MethodType type = target.type(); 483 int last = type.parameterCount() - 1; 484 if (type.parameterType(last) != arrayType) 485 target = target.asType(type.changeParameterType(last, arrayType)); 486 target = target.asFixedArity(); // make sure this attribute is turned off 487 return new AsVarargsCollector(target, arrayType); 488 } 489 490 private static final class AsVarargsCollector extends DelegatingMethodHandle { 491 private final MethodHandle target; 492 private final Class<?> arrayType; 493 private @Stable MethodHandle asCollectorCache; 494 495 AsVarargsCollector(MethodHandle target, Class<?> arrayType) { 496 this(target.type(), target, arrayType); 497 } 498 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) { 499 super(type, target); 500 this.target = target; 501 this.arrayType = arrayType; 502 this.asCollectorCache = target.asCollector(arrayType, 0); 503 } 504 505 @Override 506 public boolean isVarargsCollector() { 507 return true; 508 } 509 510 @Override 511 protected MethodHandle getTarget() { 512 return target; 513 } 514 515 @Override 516 public MethodHandle asFixedArity() { 517 return target; 518 } 519 520 @Override 521 MethodHandle setVarargs(MemberName member) { 522 if (member.isVarargs()) return this; 523 return asFixedArity(); 524 } 525 526 @Override 527 public MethodHandle withVarargs(boolean makeVarargs) { 528 if (makeVarargs) return this; 529 return asFixedArity(); 530 } 531 532 @Override 533 public MethodHandle asTypeUncached(MethodType newType) { 534 MethodType type = this.type(); 535 int collectArg = type.parameterCount() - 1; 536 int newArity = newType.parameterCount(); 537 if (newArity == collectArg+1 && 538 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) { 539 // if arity and trailing parameter are compatible, do normal thing 540 return asTypeCache = asFixedArity().asType(newType); 541 } 542 // check cache 543 MethodHandle acc = asCollectorCache; 544 if (acc != null && acc.type().parameterCount() == newArity) 545 return asTypeCache = acc.asType(newType); 546 // build and cache a collector 547 int arrayLength = newArity - collectArg; 548 MethodHandle collector; 549 try { 550 collector = asFixedArity().asCollector(arrayType, arrayLength); 551 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector; 552 } catch (IllegalArgumentException ex) { 553 throw new WrongMethodTypeException("cannot build collector", ex); 554 } 555 asCollectorCache = collector; 556 return asTypeCache = collector.asType(newType); 557 } 558 559 @Override 560 boolean viewAsTypeChecks(MethodType newType, boolean strict) { 561 super.viewAsTypeChecks(newType, true); 562 if (strict) return true; 563 // extra assertion for non-strict checks: 564 assert (type().lastParameterType().getComponentType() 565 .isAssignableFrom( 566 newType.lastParameterType().getComponentType())) 567 : Arrays.asList(this, newType); 568 return true; 569 } 570 571 @Override 572 public Object invokeWithArguments(Object... arguments) throws Throwable { 573 MethodType type = this.type(); 574 int argc; 575 final int MAX_SAFE = 127; // 127 longs require 254 slots, which is safe to spread 576 if (arguments == null 577 || (argc = arguments.length) <= MAX_SAFE 578 || argc < type.parameterCount()) { 579 return super.invokeWithArguments(arguments); 580 } 581 582 // a jumbo invocation requires more explicit reboxing of the trailing arguments 583 int uncollected = type.parameterCount() - 1; 584 Class<?> elemType = arrayType.getComponentType(); 585 int collected = argc - uncollected; 586 Object collArgs = (elemType == Object.class) 587 ? new Object[collected] : Array.newInstance(elemType, collected); 588 if (!elemType.isPrimitive()) { 589 // simple cast: just do some casting 590 try { 591 System.arraycopy(arguments, uncollected, collArgs, 0, collected); 592 } catch (ArrayStoreException ex) { 593 return super.invokeWithArguments(arguments); 594 } 595 } else { 596 // corner case of flat array requires reflection (or specialized copy loop) 597 MethodHandle arraySetter = MethodHandles.arrayElementSetter(arrayType); 598 try { 599 for (int i = 0; i < collected; i++) { 600 arraySetter.invoke(collArgs, i, arguments[uncollected + i]); 601 } 602 } catch (WrongMethodTypeException|ClassCastException ex) { 603 return super.invokeWithArguments(arguments); 604 } 605 } 606 607 // chop the jumbo list down to size and call in non-varargs mode 608 Object[] newArgs = new Object[uncollected + 1]; 609 System.arraycopy(arguments, 0, newArgs, 0, uncollected); 610 newArgs[uncollected] = collArgs; 611 return asFixedArity().invokeWithArguments(newArgs); 612 } 613 } 614 615 /** Factory method: Spread selected argument. */ 616 static MethodHandle makeSpreadArguments(MethodHandle target, 617 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) { 618 MethodType targetType = target.type(); 619 620 for (int i = 0; i < spreadArgCount; i++) { 621 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i); 622 if (arg == null) arg = Object.class; 623 targetType = targetType.changeParameterType(spreadArgPos + i, arg); 624 } 625 target = target.asType(targetType); 626 627 MethodType srcType = targetType 628 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType); 629 // Now build a LambdaForm. 630 MethodType lambdaType = srcType.invokerType(); 631 Name[] names = arguments(spreadArgCount + 2, lambdaType); 632 int nameCursor = lambdaType.parameterCount(); 633 int[] indexes = new int[targetType.parameterCount()]; 634 635 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) { 636 Class<?> src = lambdaType.parameterType(i); 637 if (i == spreadArgPos) { 638 // Spread the array. 639 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType); 640 Name array = names[argIndex]; 641 names[nameCursor++] = new Name(getFunction(NF_checkSpreadArgument), array, spreadArgCount); 642 for (int j = 0; j < spreadArgCount; i++, j++) { 643 indexes[i] = nameCursor; 644 names[nameCursor++] = new Name(new NamedFunction(aload, Intrinsic.ARRAY_LOAD), array, j); 645 } 646 } else if (i < indexes.length) { 647 indexes[i] = argIndex; 648 } 649 } 650 assert(nameCursor == names.length-1); // leave room for the final call 651 652 // Build argument array for the call. 653 Name[] targetArgs = new Name[targetType.parameterCount()]; 654 for (int i = 0; i < targetType.parameterCount(); i++) { 655 int idx = indexes[i]; 656 targetArgs[i] = names[idx]; 657 } 658 names[names.length - 1] = new Name(target, (Object[]) targetArgs); 659 660 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.SPREAD); 661 return SimpleMethodHandle.make(srcType, form); 662 } 663 664 static void checkSpreadArgument(Object av, int n) { 665 if (av == null && n == 0) { 666 return; 667 } else if (av == null) { 668 throw new NullPointerException("null array reference"); 669 } else if (av instanceof Object[]) { 670 int len = ((Object[])av).length; 671 if (len == n) return; 672 } else { 673 int len = java.lang.reflect.Array.getLength(av); 674 if (len == n) return; 675 } 676 // fall through to error: 677 throw newIllegalArgumentException("array is not of length "+n); 678 } 679 680 /** Factory method: Collect or filter selected argument(s). */ 681 static MethodHandle makeCollectArguments(MethodHandle target, 682 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) { 683 MethodType targetType = target.type(); // (a..., c, [b...])=>r 684 MethodType collectorType = collector.type(); // (b...)=>c 685 int collectArgCount = collectorType.parameterCount(); 686 Class<?> collectValType = collectorType.returnType(); 687 int collectValCount = (collectValType == void.class ? 0 : 1); 688 MethodType srcType = targetType // (a..., [b...])=>r 689 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount); 690 if (!retainOriginalArgs) { // (a..., b...)=>r 691 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterArray()); 692 } 693 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ] 694 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ] 695 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ] 696 697 // Now build a LambdaForm. 698 MethodType lambdaType = srcType.invokerType(); 699 Name[] names = arguments(2, lambdaType); 700 final int collectNamePos = names.length - 2; 701 final int targetNamePos = names.length - 1; 702 703 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount); 704 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs); 705 706 // Build argument array for the target. 707 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ]. 708 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ]. 709 Name[] targetArgs = new Name[targetType.parameterCount()]; 710 int inputArgPos = 1; // incoming LF args to copy to target 711 int targetArgPos = 0; // fill pointer for targetArgs 712 int chunk = collectArgPos; // |headArgs| 713 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 714 inputArgPos += chunk; 715 targetArgPos += chunk; 716 if (collectValType != void.class) { 717 targetArgs[targetArgPos++] = names[collectNamePos]; 718 } 719 chunk = collectArgCount; 720 if (retainOriginalArgs) { 721 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 722 targetArgPos += chunk; // optionally pass on the collected chunk 723 } 724 inputArgPos += chunk; 725 chunk = targetArgs.length - targetArgPos; // all the rest 726 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 727 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also 728 names[targetNamePos] = new Name(target, (Object[]) targetArgs); 729 730 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.COLLECT); 731 return SimpleMethodHandle.make(srcType, form); 732 } 733 734 @LambdaForm.Hidden 735 static 736 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) { 737 if (testResult) { 738 return target; 739 } else { 740 return fallback; 741 } 742 } 743 744 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies. 745 @LambdaForm.Hidden 746 @jdk.internal.HotSpotIntrinsicCandidate 747 static 748 boolean profileBoolean(boolean result, int[] counters) { 749 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively. 750 int idx = result ? 1 : 0; 751 try { 752 counters[idx] = Math.addExact(counters[idx], 1); 753 } catch (ArithmeticException e) { 754 // Avoid continuous overflow by halving the problematic count. 755 counters[idx] = counters[idx] / 2; 756 } 757 return result; 758 } 759 760 // Intrinsified by C2. Returns true if obj is a compile-time constant. 761 @LambdaForm.Hidden 762 @jdk.internal.HotSpotIntrinsicCandidate 763 static 764 boolean isCompileConstant(Object obj) { 765 return false; 766 } 767 768 static 769 MethodHandle makeGuardWithTest(MethodHandle test, 770 MethodHandle target, 771 MethodHandle fallback) { 772 MethodType type = target.type(); 773 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type)); 774 MethodType basicType = type.basicType(); 775 LambdaForm form = makeGuardWithTestForm(basicType); 776 BoundMethodHandle mh; 777 try { 778 if (PROFILE_GWT) { 779 int[] counts = new int[2]; 780 mh = (BoundMethodHandle) 781 BoundMethodHandle.speciesData_LLLL().factory().invokeBasic(type, form, 782 (Object) test, (Object) profile(target), (Object) profile(fallback), counts); 783 } else { 784 mh = (BoundMethodHandle) 785 BoundMethodHandle.speciesData_LLL().factory().invokeBasic(type, form, 786 (Object) test, (Object) profile(target), (Object) profile(fallback)); 787 } 788 } catch (Throwable ex) { 789 throw uncaughtException(ex); 790 } 791 assert(mh.type() == type); 792 return mh; 793 } 794 795 796 static 797 MethodHandle profile(MethodHandle target) { 798 if (DONT_INLINE_THRESHOLD >= 0) { 799 return makeBlockInliningWrapper(target); 800 } else { 801 return target; 802 } 803 } 804 805 /** 806 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times. 807 * Corresponding LambdaForm has @DontInline when compiled into bytecode. 808 */ 809 static 810 MethodHandle makeBlockInliningWrapper(MethodHandle target) { 811 LambdaForm lform; 812 if (DONT_INLINE_THRESHOLD > 0) { 813 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target); 814 } else { 815 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target); 816 } 817 return new CountingWrapper(target, lform, 818 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM, 819 DONT_INLINE_THRESHOLD); 820 } 821 822 private final static class Makers { 823 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */ 824 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() { 825 @Override 826 public LambdaForm apply(MethodHandle target) { 827 return DelegatingMethodHandle.makeReinvokerForm(target, 828 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, false, 829 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting); 830 } 831 }; 832 833 /** Constructs simple reinvoker lambda form for a particular method handle */ 834 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() { 835 @Override 836 public LambdaForm apply(MethodHandle target) { 837 return DelegatingMethodHandle.makeReinvokerForm(target, 838 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget); 839 } 840 }; 841 842 /** Maker of type-polymorphic varargs */ 843 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() { 844 @Override 845 protected MethodHandle[] computeValue(Class<?> type) { 846 return new MethodHandle[MAX_JVM_ARITY + 1]; 847 } 848 }; 849 } 850 851 /** 852 * Counting method handle. It has 2 states: counting and non-counting. 853 * It is in counting state for the first n invocations and then transitions to non-counting state. 854 * Behavior in counting and non-counting states is determined by lambda forms produced by 855 * countingFormProducer & nonCountingFormProducer respectively. 856 */ 857 static class CountingWrapper extends DelegatingMethodHandle { 858 private final MethodHandle target; 859 private int count; 860 private Function<MethodHandle, LambdaForm> countingFormProducer; 861 private Function<MethodHandle, LambdaForm> nonCountingFormProducer; 862 private volatile boolean isCounting; 863 864 private CountingWrapper(MethodHandle target, LambdaForm lform, 865 Function<MethodHandle, LambdaForm> countingFromProducer, 866 Function<MethodHandle, LambdaForm> nonCountingFormProducer, 867 int count) { 868 super(target.type(), lform); 869 this.target = target; 870 this.count = count; 871 this.countingFormProducer = countingFromProducer; 872 this.nonCountingFormProducer = nonCountingFormProducer; 873 this.isCounting = (count > 0); 874 } 875 876 @Hidden 877 @Override 878 protected MethodHandle getTarget() { 879 return target; 880 } 881 882 @Override 883 public MethodHandle asTypeUncached(MethodType newType) { 884 MethodHandle newTarget = target.asType(newType); 885 MethodHandle wrapper; 886 if (isCounting) { 887 LambdaForm lform; 888 lform = countingFormProducer.apply(newTarget); 889 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD); 890 } else { 891 wrapper = newTarget; // no need for a counting wrapper anymore 892 } 893 return (asTypeCache = wrapper); 894 } 895 896 // Customize target if counting happens for too long. 897 private int invocations = CUSTOMIZE_THRESHOLD; 898 private void maybeCustomizeTarget() { 899 int c = invocations; 900 if (c >= 0) { 901 if (c == 1) { 902 target.customize(); 903 } 904 invocations = c - 1; 905 } 906 } 907 908 boolean countDown() { 909 int c = count; 910 maybeCustomizeTarget(); 911 if (c <= 1) { 912 // Try to limit number of updates. 913 if (isCounting) { 914 isCounting = false; 915 return true; 916 } else { 917 return false; 918 } 919 } else { 920 count = c - 1; 921 return false; 922 } 923 } 924 925 @Hidden 926 static void maybeStopCounting(Object o1) { 927 CountingWrapper wrapper = (CountingWrapper) o1; 928 if (wrapper.countDown()) { 929 // Reached invocation threshold. Replace counting behavior with a non-counting one. 930 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target); 931 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition 932 wrapper.updateForm(lform); 933 } 934 } 935 936 static final NamedFunction NF_maybeStopCounting; 937 static { 938 Class<?> THIS_CLASS = CountingWrapper.class; 939 try { 940 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class)); 941 } catch (ReflectiveOperationException ex) { 942 throw newInternalError(ex); 943 } 944 } 945 } 946 947 static 948 LambdaForm makeGuardWithTestForm(MethodType basicType) { 949 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT); 950 if (lform != null) return lform; 951 final int THIS_MH = 0; // the BMH_LLL 952 final int ARG_BASE = 1; // start of incoming arguments 953 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 954 int nameCursor = ARG_LIMIT; 955 final int GET_TEST = nameCursor++; 956 final int GET_TARGET = nameCursor++; 957 final int GET_FALLBACK = nameCursor++; 958 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1; 959 final int CALL_TEST = nameCursor++; 960 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1; 961 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST 962 final int SELECT_ALT = nameCursor++; 963 final int CALL_TARGET = nameCursor++; 964 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative 965 966 MethodType lambdaType = basicType.invokerType(); 967 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 968 969 BoundMethodHandle.SpeciesData data = 970 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL() 971 : BoundMethodHandle.speciesData_LLL(); 972 names[THIS_MH] = names[THIS_MH].withConstraint(data); 973 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]); 974 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]); 975 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]); 976 if (GET_COUNTERS != -1) { 977 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]); 978 } 979 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class); 980 981 // call test 982 MethodType testType = basicType.changeReturnType(boolean.class).basicType(); 983 invokeArgs[0] = names[GET_TEST]; 984 names[CALL_TEST] = new Name(testType, invokeArgs); 985 986 // profile branch 987 if (PROFILE != -1) { 988 names[PROFILE] = new Name(getFunction(NF_profileBoolean), names[CALL_TEST], names[GET_COUNTERS]); 989 } 990 // call selectAlternative 991 names[SELECT_ALT] = new Name(new NamedFunction(getConstantHandle(MH_selectAlternative), Intrinsic.SELECT_ALTERNATIVE), names[TEST], names[GET_TARGET], names[GET_FALLBACK]); 992 993 // call target or fallback 994 invokeArgs[0] = names[SELECT_ALT]; 995 names[CALL_TARGET] = new Name(basicType, invokeArgs); 996 997 lform = new LambdaForm(lambdaType.parameterCount(), names, /*forceInline=*/true, Kind.GUARD); 998 999 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform); 1000 } 1001 1002 /** 1003 * The LambdaForm shape for catchException combinator is the following: 1004 * <blockquote><pre>{@code 1005 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{ 1006 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L); 1007 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L); 1008 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L); 1009 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L); 1010 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L); 1011 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L); 1012 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L); 1013 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I} 1014 * }</pre></blockquote> 1015 * 1016 * argL0 and argL2 are target and catcher method handles. argL1 is exception class. 1017 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[] 1018 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()). 1019 * 1020 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms 1021 * among catchException combinators with the same basic type. 1022 */ 1023 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) { 1024 MethodType lambdaType = basicType.invokerType(); 1025 1026 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC); 1027 if (lform != null) { 1028 return lform; 1029 } 1030 final int THIS_MH = 0; // the BMH_LLLLL 1031 final int ARG_BASE = 1; // start of incoming arguments 1032 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 1033 1034 int nameCursor = ARG_LIMIT; 1035 final int GET_TARGET = nameCursor++; 1036 final int GET_CLASS = nameCursor++; 1037 final int GET_CATCHER = nameCursor++; 1038 final int GET_COLLECT_ARGS = nameCursor++; 1039 final int GET_UNBOX_RESULT = nameCursor++; 1040 final int BOXED_ARGS = nameCursor++; 1041 final int TRY_CATCH = nameCursor++; 1042 final int UNBOX_RESULT = nameCursor++; 1043 1044 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 1045 1046 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL(); 1047 names[THIS_MH] = names[THIS_MH].withConstraint(data); 1048 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]); 1049 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]); 1050 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]); 1051 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]); 1052 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]); 1053 1054 // FIXME: rework argument boxing/result unboxing logic for LF interpretation 1055 1056 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 1057 MethodType collectArgsType = basicType.changeReturnType(Object.class); 1058 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 1059 Object[] args = new Object[invokeBasic.type().parameterCount()]; 1060 args[0] = names[GET_COLLECT_ARGS]; 1061 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE); 1062 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args); 1063 1064 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L); 1065 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]}; 1066 names[TRY_CATCH] = new Name(getFunction(NF_guardWithCatch), gwcArgs); 1067 1068 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 1069 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 1070 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]}; 1071 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 1072 1073 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.GUARD_WITH_CATCH); 1074 1075 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform); 1076 } 1077 1078 static 1079 MethodHandle makeGuardWithCatch(MethodHandle target, 1080 Class<? extends Throwable> exType, 1081 MethodHandle catcher) { 1082 MethodType type = target.type(); 1083 LambdaForm form = makeGuardWithCatchForm(type.basicType()); 1084 1085 // Prepare auxiliary method handles used during LambdaForm interpretation. 1086 // Box arguments and wrap them into Object[]: ValueConversions.array(). 1087 MethodType varargsType = type.changeReturnType(Object[].class); 1088 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 1089 MethodHandle unboxResult = unboxResultHandle(type.returnType()); 1090 1091 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL(); 1092 BoundMethodHandle mh; 1093 try { 1094 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) exType, 1095 (Object) catcher, (Object) collectArgs, (Object) unboxResult); 1096 } catch (Throwable ex) { 1097 throw uncaughtException(ex); 1098 } 1099 assert(mh.type() == type); 1100 return mh; 1101 } 1102 1103 /** 1104 * Intrinsified during LambdaForm compilation 1105 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}). 1106 */ 1107 @LambdaForm.Hidden 1108 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher, 1109 Object... av) throws Throwable { 1110 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case. 1111 try { 1112 return target.asFixedArity().invokeWithArguments(av); 1113 } catch (Throwable t) { 1114 if (!exType.isInstance(t)) throw t; 1115 return catcher.asFixedArity().invokeWithArguments(prepend(av, t)); 1116 } 1117 } 1118 1119 /** Prepend elements to an array. */ 1120 @LambdaForm.Hidden 1121 private static Object[] prepend(Object[] array, Object... elems) { 1122 int nArray = array.length; 1123 int nElems = elems.length; 1124 Object[] newArray = new Object[nArray + nElems]; 1125 System.arraycopy(elems, 0, newArray, 0, nElems); 1126 System.arraycopy(array, 0, newArray, nElems, nArray); 1127 return newArray; 1128 } 1129 1130 static 1131 MethodHandle throwException(MethodType type) { 1132 assert(Throwable.class.isAssignableFrom(type.parameterType(0))); 1133 int arity = type.parameterCount(); 1134 if (arity > 1) { 1135 MethodHandle mh = throwException(type.dropParameterTypes(1, arity)); 1136 mh = MethodHandles.dropArguments(mh, 1, Arrays.copyOfRange(type.parameterArray(), 1, arity)); 1137 return mh; 1138 } 1139 return makePairwiseConvert(getFunction(NF_throwException).resolvedHandle(), type, false, true); 1140 } 1141 1142 static <T extends Throwable> Empty throwException(T t) throws T { throw t; } 1143 1144 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2]; 1145 static MethodHandle fakeMethodHandleInvoke(MemberName method) { 1146 int idx; 1147 assert(method.isMethodHandleInvoke()); 1148 switch (method.getName()) { 1149 case "invoke": idx = 0; break; 1150 case "invokeExact": idx = 1; break; 1151 default: throw new InternalError(method.getName()); 1152 } 1153 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx]; 1154 if (mh != null) return mh; 1155 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class, 1156 MethodHandle.class, Object[].class); 1157 mh = throwException(type); 1158 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle")); 1159 if (!method.getInvocationType().equals(mh.type())) 1160 throw new InternalError(method.toString()); 1161 mh = mh.withInternalMemberName(method, false); 1162 mh = mh.withVarargs(true); 1163 assert(method.isVarargs()); 1164 FAKE_METHOD_HANDLE_INVOKE[idx] = mh; 1165 return mh; 1166 } 1167 static MethodHandle fakeVarHandleInvoke(MemberName method) { 1168 // TODO caching, is it necessary? 1169 MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class, 1170 VarHandle.class, Object[].class); 1171 MethodHandle mh = throwException(type); 1172 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle")); 1173 if (!method.getInvocationType().equals(mh.type())) 1174 throw new InternalError(method.toString()); 1175 mh = mh.withInternalMemberName(method, false); 1176 mh = mh.asVarargsCollector(Object[].class); 1177 assert(method.isVarargs()); 1178 return mh; 1179 } 1180 1181 /** 1182 * Create an alias for the method handle which, when called, 1183 * appears to be called from the same class loader and protection domain 1184 * as hostClass. 1185 * This is an expensive no-op unless the method which is called 1186 * is sensitive to its caller. A small number of system methods 1187 * are in this category, including Class.forName and Method.invoke. 1188 */ 1189 static 1190 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) { 1191 return BindCaller.bindCaller(mh, hostClass); 1192 } 1193 1194 // Put the whole mess into its own nested class. 1195 // That way we can lazily load the code and set up the constants. 1196 private static class BindCaller { 1197 private static MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class); 1198 1199 static 1200 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) { 1201 // Code in the boot layer should now be careful while creating method handles or 1202 // functional interface instances created from method references to @CallerSensitive methods, 1203 // it needs to be ensured the handles or interface instances are kept safe and are not passed 1204 // from the boot layer to untrusted code. 1205 if (hostClass == null 1206 || (hostClass.isArray() || 1207 hostClass.isPrimitive() || 1208 hostClass.getName().startsWith("java.lang.invoke."))) { 1209 throw new InternalError(); // does not happen, and should not anyway 1210 } 1211 // For simplicity, convert mh to a varargs-like method. 1212 MethodHandle vamh = prepareForInvoker(mh); 1213 // Cache the result of makeInjectedInvoker once per argument class. 1214 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass); 1215 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass); 1216 } 1217 1218 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) { 1219 try { 1220 Class<?> invokerClass = UNSAFE.defineAnonymousClass(hostClass, INJECTED_INVOKER_TEMPLATE, null); 1221 assert checkInjectedInvoker(hostClass, invokerClass); 1222 return IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT); 1223 } catch (ReflectiveOperationException ex) { 1224 throw uncaughtException(ex); 1225 } 1226 } 1227 1228 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() { 1229 @Override protected MethodHandle computeValue(Class<?> hostClass) { 1230 return makeInjectedInvoker(hostClass); 1231 } 1232 }; 1233 1234 // Adapt mh so that it can be called directly from an injected invoker: 1235 private static MethodHandle prepareForInvoker(MethodHandle mh) { 1236 mh = mh.asFixedArity(); 1237 MethodType mt = mh.type(); 1238 int arity = mt.parameterCount(); 1239 MethodHandle vamh = mh.asType(mt.generic()); 1240 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames 1241 vamh = vamh.asSpreader(Object[].class, arity); 1242 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames 1243 return vamh; 1244 } 1245 1246 // Undo the adapter effect of prepareForInvoker: 1247 private static MethodHandle restoreToType(MethodHandle vamh, 1248 MethodHandle original, 1249 Class<?> hostClass) { 1250 MethodType type = original.type(); 1251 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount()); 1252 MemberName member = original.internalMemberName(); 1253 mh = mh.asType(type); 1254 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass); 1255 return mh; 1256 } 1257 1258 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) { 1259 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)"; 1260 try { 1261 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)"; 1262 } catch (SecurityException ex) { 1263 // Self-check was blocked by security manager. This is OK. 1264 } 1265 try { 1266 // Test the invoker to ensure that it really injects into the right place. 1267 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT); 1268 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass); 1269 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass }); 1270 } catch (Throwable ex) { 1271 throw new InternalError(ex); 1272 } 1273 } 1274 1275 private static final MethodHandle MH_checkCallerClass; 1276 static { 1277 final Class<?> THIS_CLASS = BindCaller.class; 1278 assert(checkCallerClass(THIS_CLASS)); 1279 try { 1280 MH_checkCallerClass = IMPL_LOOKUP 1281 .findStatic(THIS_CLASS, "checkCallerClass", 1282 MethodType.methodType(boolean.class, Class.class)); 1283 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS)); 1284 } catch (Throwable ex) { 1285 throw new InternalError(ex); 1286 } 1287 } 1288 1289 @CallerSensitive 1290 @ForceInline // to ensure Reflection.getCallerClass optimization 1291 private static boolean checkCallerClass(Class<?> expected) { 1292 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here. 1293 Class<?> actual = Reflection.getCallerClass(); 1294 if (actual != expected) 1295 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName()); 1296 return true; 1297 } 1298 1299 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate(); 1300 1301 /** Produces byte code for a class that is used as an injected invoker. */ 1302 private static byte[] generateInvokerTemplate() { 1303 ClassWriter cw = new ClassWriter(0); 1304 1305 // private static class InjectedInvoker { 1306 // @Hidden 1307 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable { 1308 // return vamh.invokeExact(args); 1309 // } 1310 // } 1311 cw.visit(52, ACC_PRIVATE | ACC_SUPER, "InjectedInvoker", null, "java/lang/Object", null); 1312 1313 MethodVisitor mv = cw.visitMethod(ACC_STATIC, "invoke_V", 1314 "(Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;", 1315 null, null); 1316 1317 // Suppress invoker method in stack traces. 1318 AnnotationVisitor av0 = mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1319 av0.visitEnd(); 1320 1321 mv.visitCode(); 1322 mv.visitVarInsn(ALOAD, 0); 1323 mv.visitVarInsn(ALOAD, 1); 1324 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle", "invokeExact", 1325 "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1326 mv.visitInsn(ARETURN); 1327 mv.visitMaxs(2, 2); 1328 mv.visitEnd(); 1329 1330 cw.visitEnd(); 1331 return cw.toByteArray(); 1332 } 1333 } 1334 1335 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */ 1336 private static final class WrappedMember extends DelegatingMethodHandle { 1337 private final MethodHandle target; 1338 private final MemberName member; 1339 private final Class<?> callerClass; 1340 private final boolean isInvokeSpecial; 1341 1342 private WrappedMember(MethodHandle target, MethodType type, 1343 MemberName member, boolean isInvokeSpecial, 1344 Class<?> callerClass) { 1345 super(type, target); 1346 this.target = target; 1347 this.member = member; 1348 this.callerClass = callerClass; 1349 this.isInvokeSpecial = isInvokeSpecial; 1350 } 1351 1352 @Override 1353 MemberName internalMemberName() { 1354 return member; 1355 } 1356 @Override 1357 Class<?> internalCallerClass() { 1358 return callerClass; 1359 } 1360 @Override 1361 boolean isInvokeSpecial() { 1362 return isInvokeSpecial; 1363 } 1364 @Override 1365 protected MethodHandle getTarget() { 1366 return target; 1367 } 1368 @Override 1369 public MethodHandle asTypeUncached(MethodType newType) { 1370 // This MH is an alias for target, except for the MemberName 1371 // Drop the MemberName if there is any conversion. 1372 return asTypeCache = target.asType(newType); 1373 } 1374 } 1375 1376 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) { 1377 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial()) 1378 return target; 1379 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null); 1380 } 1381 1382 /** Intrinsic IDs */ 1383 /*non-public*/ 1384 enum Intrinsic { 1385 SELECT_ALTERNATIVE, 1386 GUARD_WITH_CATCH, 1387 TRY_FINALLY, 1388 LOOP, 1389 NEW_ARRAY, 1390 ARRAY_LOAD, 1391 ARRAY_STORE, 1392 ARRAY_LENGTH, 1393 IDENTITY, 1394 ZERO, 1395 NONE // no intrinsic associated 1396 } 1397 1398 /** Mark arbitrary method handle as intrinsic. 1399 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */ 1400 static final class IntrinsicMethodHandle extends DelegatingMethodHandle { 1401 private final MethodHandle target; 1402 private final Intrinsic intrinsicName; 1403 1404 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) { 1405 super(target.type(), target); 1406 this.target = target; 1407 this.intrinsicName = intrinsicName; 1408 } 1409 1410 @Override 1411 protected MethodHandle getTarget() { 1412 return target; 1413 } 1414 1415 @Override 1416 Intrinsic intrinsicName() { 1417 return intrinsicName; 1418 } 1419 1420 @Override 1421 public MethodHandle asTypeUncached(MethodType newType) { 1422 // This MH is an alias for target, except for the intrinsic name 1423 // Drop the name if there is any conversion. 1424 return asTypeCache = target.asType(newType); 1425 } 1426 1427 @Override 1428 String internalProperties() { 1429 return super.internalProperties() + 1430 "\n& Intrinsic="+intrinsicName; 1431 } 1432 1433 @Override 1434 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) { 1435 if (intrinsicName == Intrinsic.IDENTITY) { 1436 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength); 1437 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength); 1438 return newArray.asType(resultType); 1439 } 1440 return super.asCollector(arrayType, arrayLength); 1441 } 1442 } 1443 1444 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) { 1445 if (intrinsicName == target.intrinsicName()) 1446 return target; 1447 return new IntrinsicMethodHandle(target, intrinsicName); 1448 } 1449 1450 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) { 1451 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName); 1452 } 1453 1454 /// Collection of multiple arguments. 1455 1456 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) { 1457 MethodType type = MethodType.genericMethodType(nargs) 1458 .changeReturnType(rtype) 1459 .insertParameterTypes(0, ptypes); 1460 try { 1461 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type); 1462 } catch (ReflectiveOperationException ex) { 1463 return null; 1464 } 1465 } 1466 1467 private static final Object[] NO_ARGS_ARRAY = {}; 1468 private static Object[] makeArray(Object... args) { return args; } 1469 private static Object[] array() { return NO_ARGS_ARRAY; } 1470 private static Object[] array(Object a0) 1471 { return makeArray(a0); } 1472 private static Object[] array(Object a0, Object a1) 1473 { return makeArray(a0, a1); } 1474 private static Object[] array(Object a0, Object a1, Object a2) 1475 { return makeArray(a0, a1, a2); } 1476 private static Object[] array(Object a0, Object a1, Object a2, Object a3) 1477 { return makeArray(a0, a1, a2, a3); } 1478 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1479 Object a4) 1480 { return makeArray(a0, a1, a2, a3, a4); } 1481 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1482 Object a4, Object a5) 1483 { return makeArray(a0, a1, a2, a3, a4, a5); } 1484 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1485 Object a4, Object a5, Object a6) 1486 { return makeArray(a0, a1, a2, a3, a4, a5, a6); } 1487 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1488 Object a4, Object a5, Object a6, Object a7) 1489 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); } 1490 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1491 Object a4, Object a5, Object a6, Object a7, 1492 Object a8) 1493 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); } 1494 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1495 Object a4, Object a5, Object a6, Object a7, 1496 Object a8, Object a9) 1497 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); } 1498 1499 private static final int ARRAYS_COUNT = 11; 1500 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1]; 1501 1502 // filling versions of the above: 1503 // using Integer len instead of int len and no varargs to avoid bootstrapping problems 1504 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) { 1505 Object[] a = new Object[len]; 1506 fillWithArguments(a, 0, args); 1507 return a; 1508 } 1509 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) { 1510 Object[] a = Arrays.copyOf(example, len); 1511 assert(a.getClass() != Object[].class); 1512 fillWithArguments(a, 0, args); 1513 return a; 1514 } 1515 private static void fillWithArguments(Object[] a, int pos, Object... args) { 1516 System.arraycopy(args, 0, a, pos, args.length); 1517 } 1518 // using Integer pos instead of int pos to avoid bootstrapping problems 1519 private static Object[] fillArray(Integer pos, Object[] a, Object a0) 1520 { fillWithArguments(a, pos, a0); return a; } 1521 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1) 1522 { fillWithArguments(a, pos, a0, a1); return a; } 1523 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2) 1524 { fillWithArguments(a, pos, a0, a1, a2); return a; } 1525 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3) 1526 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; } 1527 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1528 Object a4) 1529 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; } 1530 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1531 Object a4, Object a5) 1532 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; } 1533 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1534 Object a4, Object a5, Object a6) 1535 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; } 1536 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1537 Object a4, Object a5, Object a6, Object a7) 1538 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; } 1539 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1540 Object a4, Object a5, Object a6, Object a7, 1541 Object a8) 1542 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; } 1543 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1544 Object a4, Object a5, Object a6, Object a7, 1545 Object a8, Object a9) 1546 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; } 1547 1548 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods 1549 private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT]; 1550 1551 private static MethodHandle getFillArray(int count) { 1552 assert (count > 0 && count < FILL_ARRAYS_COUNT); 1553 MethodHandle mh = FILL_ARRAYS[count]; 1554 if (mh != null) { 1555 return mh; 1556 } 1557 mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class); 1558 FILL_ARRAYS[count] = mh; 1559 return mh; 1560 } 1561 1562 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) { 1563 Object a = w.makeArray(boxes.length); 1564 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length); 1565 return a; 1566 } 1567 1568 /** Return a method handle that takes the indicated number of Object 1569 * arguments and returns an Object array of them, as if for varargs. 1570 */ 1571 static MethodHandle varargsArray(int nargs) { 1572 MethodHandle mh = ARRAYS[nargs]; 1573 if (mh != null) { 1574 return mh; 1575 } 1576 if (nargs < ARRAYS_COUNT) { 1577 mh = findCollector("array", nargs, Object[].class); 1578 } else { 1579 mh = buildVarargsArray(getConstantHandle(MH_fillNewArray), 1580 getConstantHandle(MH_arrayIdentity), nargs); 1581 } 1582 assert(assertCorrectArity(mh, nargs)); 1583 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY); 1584 return ARRAYS[nargs] = mh; 1585 } 1586 1587 private static boolean assertCorrectArity(MethodHandle mh, int arity) { 1588 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh; 1589 return true; 1590 } 1591 1592 // Array identity function (used as getConstantHandle(MH_arrayIdentity)). 1593 static <T> T[] identity(T[] x) { 1594 return x; 1595 } 1596 1597 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) { 1598 // Build up the result mh as a sequence of fills like this: 1599 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23)) 1600 // The various fill(_,10*I,___*[J]) are reusable. 1601 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately 1602 int rightLen = nargs - leftLen; 1603 MethodHandle leftCollector = newArray.bindTo(nargs); 1604 leftCollector = leftCollector.asCollector(Object[].class, leftLen); 1605 MethodHandle mh = finisher; 1606 if (rightLen > 0) { 1607 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen); 1608 if (mh.equals(getConstantHandle(MH_arrayIdentity))) 1609 mh = rightFiller; 1610 else 1611 mh = MethodHandles.collectArguments(mh, 0, rightFiller); 1612 } 1613 if (mh.equals(getConstantHandle(MH_arrayIdentity))) 1614 mh = leftCollector; 1615 else 1616 mh = MethodHandles.collectArguments(mh, 0, leftCollector); 1617 return mh; 1618 } 1619 1620 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1; 1621 private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1]; 1622 /** fill_array_to_right(N).invoke(a, argL..arg[N-1]) 1623 * fills a[L]..a[N-1] with corresponding arguments, 1624 * and then returns a. The value L is a global constant (LEFT_ARGS). 1625 */ 1626 private static MethodHandle fillToRight(int nargs) { 1627 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs]; 1628 if (filler != null) return filler; 1629 filler = buildFiller(nargs); 1630 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1)); 1631 return FILL_ARRAY_TO_RIGHT[nargs] = filler; 1632 } 1633 private static MethodHandle buildFiller(int nargs) { 1634 if (nargs <= LEFT_ARGS) 1635 return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged 1636 // we need room for both mh and a in mh.invoke(a, arg*[nargs]) 1637 final int CHUNK = LEFT_ARGS; 1638 int rightLen = nargs % CHUNK; 1639 int midLen = nargs - rightLen; 1640 if (rightLen == 0) { 1641 midLen = nargs - (rightLen = CHUNK); 1642 if (FILL_ARRAY_TO_RIGHT[midLen] == null) { 1643 // build some precursors from left to right 1644 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK) 1645 if (j > LEFT_ARGS) fillToRight(j); 1646 } 1647 } 1648 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS); 1649 assert(rightLen > 0); 1650 MethodHandle midFill = fillToRight(midLen); // recursive fill 1651 MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1] 1652 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS); 1653 assert(rightFill.type().parameterCount() == 1 + rightLen); 1654 1655 // Combine the two fills: 1656 // right(mid(a, x10..x19), x20..x23) 1657 // The final product will look like this: 1658 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23) 1659 if (midLen == LEFT_ARGS) 1660 return rightFill; 1661 else 1662 return MethodHandles.collectArguments(rightFill, 0, midFill); 1663 } 1664 1665 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM 1666 1667 /** Return a method handle that takes the indicated number of 1668 * typed arguments and returns an array of them. 1669 * The type argument is the array type. 1670 */ 1671 static MethodHandle varargsArray(Class<?> arrayType, int nargs) { 1672 Class<?> elemType = arrayType.getComponentType(); 1673 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType); 1674 // FIXME: Need more special casing and caching here. 1675 if (nargs >= MAX_JVM_ARITY/2 - 1) { 1676 int slots = nargs; 1677 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH 1678 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive()) 1679 slots *= Wrapper.forPrimitiveType(elemType).stackSlots(); 1680 if (slots > MAX_ARRAY_SLOTS) 1681 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs); 1682 } 1683 if (elemType == Object.class) 1684 return varargsArray(nargs); 1685 // other cases: primitive arrays, subtypes of Object[] 1686 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType); 1687 MethodHandle mh = nargs < cache.length ? cache[nargs] : null; 1688 if (mh != null) return mh; 1689 if (nargs == 0) { 1690 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0); 1691 mh = MethodHandles.constant(arrayType, example); 1692 } else if (elemType.isPrimitive()) { 1693 MethodHandle builder = getConstantHandle(MH_fillNewArray); 1694 MethodHandle producer = buildArrayProducer(arrayType); 1695 mh = buildVarargsArray(builder, producer, nargs); 1696 } else { 1697 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class); 1698 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType); 1699 MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example); 1700 MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed 1701 mh = buildVarargsArray(builder, producer, nargs); 1702 } 1703 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType))); 1704 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY); 1705 assert(assertCorrectArity(mh, nargs)); 1706 if (nargs < cache.length) 1707 cache[nargs] = mh; 1708 return mh; 1709 } 1710 1711 private static MethodHandle buildArrayProducer(Class<?> arrayType) { 1712 Class<?> elemType = arrayType.getComponentType(); 1713 assert(elemType.isPrimitive()); 1714 return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType)); 1715 } 1716 1717 /*non-public*/ static void assertSame(Object mh1, Object mh2) { 1718 if (mh1 != mh2) { 1719 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)", 1720 mh1, ((MethodHandle)mh1).form, 1721 mh2, ((MethodHandle)mh2).form); 1722 throw newInternalError(msg); 1723 } 1724 } 1725 1726 // Local constant functions: 1727 1728 /* non-public */ 1729 static final byte NF_checkSpreadArgument = 0, 1730 NF_guardWithCatch = 1, 1731 NF_throwException = 2, 1732 NF_tryFinally = 3, 1733 NF_loop = 4, 1734 NF_profileBoolean = 5, 1735 NF_LIMIT = 6; 1736 1737 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT]; 1738 1739 static NamedFunction getFunction(byte func) { 1740 NamedFunction nf = NFS[func]; 1741 if (nf != null) { 1742 return nf; 1743 } 1744 return NFS[func] = createFunction(func); 1745 } 1746 1747 private static NamedFunction createFunction(byte func) { 1748 try { 1749 switch (func) { 1750 case NF_checkSpreadArgument: 1751 return new NamedFunction(MethodHandleImpl.class 1752 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class)); 1753 case NF_guardWithCatch: 1754 return new NamedFunction(MethodHandleImpl.class 1755 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class, 1756 MethodHandle.class, Object[].class)); 1757 case NF_tryFinally: 1758 return new NamedFunction(MethodHandleImpl.class 1759 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class)); 1760 case NF_loop: 1761 return new NamedFunction(MethodHandleImpl.class 1762 .getDeclaredMethod("loop", BasicType[].class, LoopClauses.class, Object[].class)); 1763 case NF_throwException: 1764 return new NamedFunction(MethodHandleImpl.class 1765 .getDeclaredMethod("throwException", Throwable.class)); 1766 case NF_profileBoolean: 1767 return new NamedFunction(MethodHandleImpl.class 1768 .getDeclaredMethod("profileBoolean", boolean.class, int[].class)); 1769 default: 1770 throw new InternalError("Undefined function: " + func); 1771 } 1772 } catch (ReflectiveOperationException ex) { 1773 throw newInternalError(ex); 1774 } 1775 } 1776 1777 static { 1778 SharedSecrets.setJavaLangInvokeAccess(new JavaLangInvokeAccess() { 1779 @Override 1780 public Object newMemberName() { 1781 return new MemberName(); 1782 } 1783 1784 @Override 1785 public String getName(Object mname) { 1786 MemberName memberName = (MemberName)mname; 1787 return memberName.getName(); 1788 } 1789 @Override 1790 public Class<?> getDeclaringClass(Object mname) { 1791 MemberName memberName = (MemberName)mname; 1792 return memberName.getDeclaringClass(); 1793 } 1794 1795 @Override 1796 public MethodType getMethodType(Object mname) { 1797 MemberName memberName = (MemberName)mname; 1798 return memberName.getMethodType(); 1799 } 1800 1801 @Override 1802 public String getMethodDescriptor(Object mname) { 1803 MemberName memberName = (MemberName)mname; 1804 return memberName.getMethodDescriptor(); 1805 } 1806 1807 @Override 1808 public boolean isNative(Object mname) { 1809 MemberName memberName = (MemberName)mname; 1810 return memberName.isNative(); 1811 } 1812 1813 @Override 1814 public byte[] generateDirectMethodHandleHolderClassBytes( 1815 String className, MethodType[] methodTypes, int[] types) { 1816 return GenerateJLIClassesHelper 1817 .generateDirectMethodHandleHolderClassBytes( 1818 className, methodTypes, types); 1819 } 1820 1821 @Override 1822 public byte[] generateDelegatingMethodHandleHolderClassBytes( 1823 String className, MethodType[] methodTypes) { 1824 return GenerateJLIClassesHelper 1825 .generateDelegatingMethodHandleHolderClassBytes( 1826 className, methodTypes); 1827 } 1828 1829 @Override 1830 public Map.Entry<String, byte[]> generateConcreteBMHClassBytes( 1831 final String types) { 1832 return GenerateJLIClassesHelper 1833 .generateConcreteBMHClassBytes(types); 1834 } 1835 1836 @Override 1837 public byte[] generateBasicFormsClassBytes(final String className) { 1838 return GenerateJLIClassesHelper 1839 .generateBasicFormsClassBytes(className); 1840 } 1841 1842 @Override 1843 public byte[] generateInvokersHolderClassBytes(final String className, 1844 MethodType[] methodTypes) { 1845 return GenerateJLIClassesHelper 1846 .generateInvokersHolderClassBytes(className, methodTypes); 1847 } 1848 }); 1849 } 1850 1851 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */ 1852 private static MethodHandle unboxResultHandle(Class<?> returnType) { 1853 if (returnType.isPrimitive()) { 1854 if (returnType == void.class) { 1855 return ValueConversions.ignore(); 1856 } else { 1857 Wrapper w = Wrapper.forPrimitiveType(returnType); 1858 return ValueConversions.unboxExact(w); 1859 } 1860 } else { 1861 return MethodHandles.identity(Object.class); 1862 } 1863 } 1864 1865 /** 1866 * Assembles a loop method handle from the given handles and type information. 1867 * 1868 * @param tloop the return type of the loop. 1869 * @param targs types of the arguments to be passed to the loop. 1870 * @param init sanitized array of initializers for loop-local variables. 1871 * @param step sanitited array of loop bodies. 1872 * @param pred sanitized array of predicates. 1873 * @param fini sanitized array of loop finalizers. 1874 * 1875 * @return a handle that, when invoked, will execute the loop. 1876 */ 1877 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step, 1878 List<MethodHandle> pred, List<MethodHandle> fini) { 1879 MethodType type = MethodType.methodType(tloop, targs); 1880 BasicType[] initClauseTypes = 1881 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new); 1882 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes); 1883 1884 // Prepare auxiliary method handles used during LambdaForm interpretation. 1885 // Box arguments and wrap them into Object[]: ValueConversions.array(). 1886 MethodType varargsType = type.changeReturnType(Object[].class); 1887 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 1888 MethodHandle unboxResult = unboxResultHandle(tloop); 1889 1890 LoopClauses clauseData = 1891 new LoopClauses(new MethodHandle[][]{toArray(init), toArray(step), toArray(pred), toArray(fini)}); 1892 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL(); 1893 BoundMethodHandle mh; 1894 try { 1895 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) clauseData, 1896 (Object) collectArgs, (Object) unboxResult); 1897 } catch (Throwable ex) { 1898 throw uncaughtException(ex); 1899 } 1900 assert(mh.type() == type); 1901 return mh; 1902 } 1903 1904 private static MethodHandle[] toArray(List<MethodHandle> l) { 1905 return l.toArray(new MethodHandle[0]); 1906 } 1907 1908 /** 1909 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are 1910 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one 1911 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by 1912 * {@code t12}): 1913 * <blockquote><pre>{@code 1914 * loop=Lambda(a0:L,a1:L)=>{ 1915 * t2:L=BoundMethodHandle$Species_L3.argL0(a0:L); // LoopClauses holding init, step, pred, fini handles 1916 * t3:L=BoundMethodHandle$Species_L3.argL1(a0:L); // helper handle to box the arguments into an Object[] 1917 * t4:L=BoundMethodHandle$Species_L3.argL2(a0:L); // helper handle to unbox the result 1918 * t5:L=MethodHandle.invokeBasic(t3:L,a1:L); // box the arguments into an Object[] 1919 * t6:L=MethodHandleImpl.loop(null,t2:L,t3:L); // call the loop executor 1920 * t7:L=MethodHandle.invokeBasic(t4:L,t6:L);t7:L} // unbox the result; return the result 1921 * }</pre></blockquote> 1922 * <p> 1923 * {@code argL0} is a LoopClauses instance holding, in a 2-dimensional array, the init, step, pred, and fini method 1924 * handles. {@code argL1} and {@code argL2} are auxiliary method handles: {@code argL1} boxes arguments and wraps 1925 * them into {@code Object[]} ({@code ValueConversions.array()}), and {@code argL2} unboxes the result if necessary 1926 * ({@code ValueConversions.unbox()}). 1927 * <p> 1928 * Having {@code t3} and {@code t4} passed in via a BMH and not hardcoded in the lambda form allows to share lambda 1929 * forms among loop combinators with the same basic type. 1930 * <p> 1931 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to 1932 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is 1933 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int) 1934 * bytecode generation}. 1935 */ 1936 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) { 1937 MethodType lambdaType = basicType.invokerType(); 1938 1939 final int THIS_MH = 0; // the BMH_LLL 1940 final int ARG_BASE = 1; // start of incoming arguments 1941 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 1942 1943 int nameCursor = ARG_LIMIT; 1944 final int GET_CLAUSE_DATA = nameCursor++; 1945 final int GET_COLLECT_ARGS = nameCursor++; 1946 final int GET_UNBOX_RESULT = nameCursor++; 1947 final int BOXED_ARGS = nameCursor++; 1948 final int LOOP = nameCursor++; 1949 final int UNBOX_RESULT = nameCursor++; 1950 1951 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP); 1952 if (lform == null) { 1953 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 1954 1955 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL(); 1956 names[THIS_MH] = names[THIS_MH].withConstraint(data); 1957 names[GET_CLAUSE_DATA] = new Name(data.getterFunction(0), names[THIS_MH]); 1958 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(1), names[THIS_MH]); 1959 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(2), names[THIS_MH]); 1960 1961 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 1962 MethodType collectArgsType = basicType.changeReturnType(Object.class); 1963 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 1964 Object[] args = new Object[invokeBasic.type().parameterCount()]; 1965 args[0] = names[GET_COLLECT_ARGS]; 1966 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE); 1967 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.LOOP), args); 1968 1969 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,clauses:L,t_{i}:L); 1970 Object[] lArgs = 1971 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor 1972 names[GET_CLAUSE_DATA], names[BOXED_ARGS]}; 1973 names[LOOP] = new Name(getFunction(NF_loop), lArgs); 1974 1975 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 1976 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 1977 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]}; 1978 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 1979 1980 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP, 1981 new LambdaForm(lambdaType.parameterCount(), names, Kind.LOOP)); 1982 } 1983 1984 // BOXED_ARGS is the index into the names array where the loop idiom starts 1985 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes); 1986 } 1987 1988 static class LoopClauses { 1989 @Stable final MethodHandle[][] clauses; 1990 LoopClauses(MethodHandle[][] clauses) { 1991 assert clauses.length == 4; 1992 this.clauses = clauses; 1993 } 1994 @Override 1995 public String toString() { 1996 StringBuffer sb = new StringBuffer("LoopClauses -- "); 1997 for (int i = 0; i < 4; ++i) { 1998 if (i > 0) { 1999 sb.append(" "); 2000 } 2001 sb.append('<').append(i).append(">: "); 2002 MethodHandle[] hs = clauses[i]; 2003 for (int j = 0; j < hs.length; ++j) { 2004 if (j > 0) { 2005 sb.append(" "); 2006 } 2007 sb.append('*').append(j).append(": ").append(hs[j]).append('\n'); 2008 } 2009 } 2010 sb.append(" --\n"); 2011 return sb.toString(); 2012 } 2013 } 2014 2015 /** 2016 * Intrinsified during LambdaForm compilation 2017 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}). 2018 */ 2019 @LambdaForm.Hidden 2020 static Object loop(BasicType[] localTypes, LoopClauses clauseData, Object... av) throws Throwable { 2021 final MethodHandle[] init = clauseData.clauses[0]; 2022 final MethodHandle[] step = clauseData.clauses[1]; 2023 final MethodHandle[] pred = clauseData.clauses[2]; 2024 final MethodHandle[] fini = clauseData.clauses[3]; 2025 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count(); 2026 int nArgs = init[0].type().parameterCount(); 2027 Object[] varsAndArgs = new Object[varSize + nArgs]; 2028 for (int i = 0, v = 0; i < init.length; ++i) { 2029 MethodHandle ih = init[i]; 2030 if (ih.type().returnType() == void.class) { 2031 ih.invokeWithArguments(av); 2032 } else { 2033 varsAndArgs[v++] = ih.invokeWithArguments(av); 2034 } 2035 } 2036 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs); 2037 final int nSteps = step.length; 2038 for (; ; ) { 2039 for (int i = 0, v = 0; i < nSteps; ++i) { 2040 MethodHandle p = pred[i]; 2041 MethodHandle s = step[i]; 2042 MethodHandle f = fini[i]; 2043 if (s.type().returnType() == void.class) { 2044 s.invokeWithArguments(varsAndArgs); 2045 } else { 2046 varsAndArgs[v++] = s.invokeWithArguments(varsAndArgs); 2047 } 2048 if (!(boolean) p.invokeWithArguments(varsAndArgs)) { 2049 return f.invokeWithArguments(varsAndArgs); 2050 } 2051 } 2052 } 2053 } 2054 2055 /** 2056 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, 2057 * MethodHandle) counting loops}. 2058 * 2059 * @param limit the upper bound of the parameter, statically bound at loop creation time. 2060 * @param counter the counter parameter, passed in during loop execution. 2061 * 2062 * @return whether the counter has reached the limit. 2063 */ 2064 static boolean countedLoopPredicate(int limit, int counter) { 2065 return counter < limit; 2066 } 2067 2068 /** 2069 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, 2070 * MethodHandle) counting loops} to increment the counter. 2071 * 2072 * @param limit the upper bound of the loop counter (ignored). 2073 * @param counter the loop counter. 2074 * 2075 * @return the loop counter incremented by 1. 2076 */ 2077 static int countedLoopStep(int limit, int counter) { 2078 return counter + 1; 2079 } 2080 2081 /** 2082 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}. 2083 * 2084 * @param it the {@link Iterable} over which the loop iterates. 2085 * 2086 * @return an {@link Iterator} over the argument's elements. 2087 */ 2088 static Iterator<?> initIterator(Iterable<?> it) { 2089 return it.iterator(); 2090 } 2091 2092 /** 2093 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}. 2094 * 2095 * @param it the iterator to be checked. 2096 * 2097 * @return {@code true} iff there are more elements to iterate over. 2098 */ 2099 static boolean iteratePredicate(Iterator<?> it) { 2100 return it.hasNext(); 2101 } 2102 2103 /** 2104 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain 2105 * MethodHandles#iteratedLoop iterating loops}. 2106 * 2107 * @param it the iterator. 2108 * 2109 * @return the next element from the iterator. 2110 */ 2111 static Object iterateNext(Iterator<?> it) { 2112 return it.next(); 2113 } 2114 2115 /** 2116 * Makes a {@code try-finally} handle that conforms to the type constraints. 2117 * 2118 * @param target the target to execute in a {@code try-finally} block. 2119 * @param cleanup the cleanup to execute in the {@code finally} block. 2120 * @param rtype the result type of the entire construct. 2121 * @param argTypes the types of the arguments. 2122 * 2123 * @return a handle on the constructed {@code try-finally} block. 2124 */ 2125 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, List<Class<?>> argTypes) { 2126 MethodType type = MethodType.methodType(rtype, argTypes); 2127 LambdaForm form = makeTryFinallyForm(type.basicType()); 2128 2129 // Prepare auxiliary method handles used during LambdaForm interpretation. 2130 // Box arguments and wrap them into Object[]: ValueConversions.array(). 2131 MethodType varargsType = type.changeReturnType(Object[].class); 2132 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 2133 MethodHandle unboxResult = unboxResultHandle(rtype); 2134 2135 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL(); 2136 BoundMethodHandle mh; 2137 try { 2138 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) cleanup, 2139 (Object) collectArgs, (Object) unboxResult); 2140 } catch (Throwable ex) { 2141 throw uncaughtException(ex); 2142 } 2143 assert(mh.type() == type); 2144 return mh; 2145 } 2146 2147 /** 2148 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in 2149 * {@code a1}, and a reference return type, with the return value represented by {@code t8}): 2150 * <blockquote><pre>{@code 2151 * tryFinally=Lambda(a0:L,a1:L)=>{ 2152 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle 2153 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle 2154 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[] 2155 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result 2156 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[] 2157 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor 2158 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result 2159 * }</pre></blockquote> 2160 * <p> 2161 * {@code argL0} and {@code argL1} are the target and cleanup method handles. 2162 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into 2163 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary 2164 * ({@code ValueConversions.unbox()}). 2165 * <p> 2166 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda 2167 * forms among tryFinally combinators with the same basic type. 2168 */ 2169 private static LambdaForm makeTryFinallyForm(MethodType basicType) { 2170 MethodType lambdaType = basicType.invokerType(); 2171 2172 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF); 2173 if (lform != null) { 2174 return lform; 2175 } 2176 final int THIS_MH = 0; // the BMH_LLLL 2177 final int ARG_BASE = 1; // start of incoming arguments 2178 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 2179 2180 int nameCursor = ARG_LIMIT; 2181 final int GET_TARGET = nameCursor++; 2182 final int GET_CLEANUP = nameCursor++; 2183 final int GET_COLLECT_ARGS = nameCursor++; 2184 final int GET_UNBOX_RESULT = nameCursor++; 2185 final int BOXED_ARGS = nameCursor++; 2186 final int TRY_FINALLY = nameCursor++; 2187 final int UNBOX_RESULT = nameCursor++; 2188 2189 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 2190 2191 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL(); 2192 names[THIS_MH] = names[THIS_MH].withConstraint(data); 2193 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]); 2194 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]); 2195 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]); 2196 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]); 2197 2198 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 2199 MethodType collectArgsType = basicType.changeReturnType(Object.class); 2200 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 2201 Object[] args = new Object[invokeBasic.type().parameterCount()]; 2202 args[0] = names[GET_COLLECT_ARGS]; 2203 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE); 2204 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.TRY_FINALLY), args); 2205 2206 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L); 2207 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]}; 2208 names[TRY_FINALLY] = new Name(getFunction(NF_tryFinally), tfArgs); 2209 2210 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 2211 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 2212 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]}; 2213 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 2214 2215 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.TRY_FINALLY); 2216 2217 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform); 2218 } 2219 2220 /** 2221 * Intrinsified during LambdaForm compilation 2222 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}). 2223 */ 2224 @LambdaForm.Hidden 2225 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable { 2226 Throwable t = null; 2227 Object r = null; 2228 try { 2229 r = target.invokeWithArguments(av); 2230 } catch (Throwable thrown) { 2231 t = thrown; 2232 throw t; 2233 } finally { 2234 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r); 2235 r = cleanup.invokeWithArguments(args); 2236 } 2237 return r; 2238 } 2239 2240 // Indexes into constant method handles: 2241 static final int 2242 MH_cast = 0, 2243 MH_selectAlternative = 1, 2244 MH_copyAsPrimitiveArray = 2, 2245 MH_fillNewTypedArray = 3, 2246 MH_fillNewArray = 4, 2247 MH_arrayIdentity = 5, 2248 MH_countedLoopPred = 6, 2249 MH_countedLoopStep = 7, 2250 MH_initIterator = 8, 2251 MH_iteratePred = 9, 2252 MH_iterateNext = 10, 2253 MH_Array_newInstance = 11, 2254 MH_LIMIT = 12; 2255 2256 static MethodHandle getConstantHandle(int idx) { 2257 MethodHandle handle = HANDLES[idx]; 2258 if (handle != null) { 2259 return handle; 2260 } 2261 return setCachedHandle(idx, makeConstantHandle(idx)); 2262 } 2263 2264 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) { 2265 // Simulate a CAS, to avoid racy duplication of results. 2266 MethodHandle prev = HANDLES[idx]; 2267 if (prev != null) { 2268 return prev; 2269 } 2270 HANDLES[idx] = method; 2271 return method; 2272 } 2273 2274 // Local constant method handles: 2275 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT]; 2276 2277 private static MethodHandle makeConstantHandle(int idx) { 2278 try { 2279 switch (idx) { 2280 case MH_cast: 2281 return IMPL_LOOKUP.findVirtual(Class.class, "cast", 2282 MethodType.methodType(Object.class, Object.class)); 2283 case MH_copyAsPrimitiveArray: 2284 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray", 2285 MethodType.methodType(Object.class, Wrapper.class, Object[].class)); 2286 case MH_arrayIdentity: 2287 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity", 2288 MethodType.methodType(Object[].class, Object[].class)); 2289 case MH_fillNewArray: 2290 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray", 2291 MethodType.methodType(Object[].class, Integer.class, Object[].class)); 2292 case MH_fillNewTypedArray: 2293 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray", 2294 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class)); 2295 case MH_selectAlternative: 2296 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative", 2297 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class)); 2298 case MH_countedLoopPred: 2299 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate", 2300 MethodType.methodType(boolean.class, int.class, int.class)); 2301 case MH_countedLoopStep: 2302 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep", 2303 MethodType.methodType(int.class, int.class, int.class)); 2304 case MH_initIterator: 2305 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator", 2306 MethodType.methodType(Iterator.class, Iterable.class)); 2307 case MH_iteratePred: 2308 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate", 2309 MethodType.methodType(boolean.class, Iterator.class)); 2310 case MH_iterateNext: 2311 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext", 2312 MethodType.methodType(Object.class, Iterator.class)); 2313 case MH_Array_newInstance: 2314 return IMPL_LOOKUP.findStatic(Array.class, "newInstance", 2315 MethodType.methodType(Object.class, Class.class, int.class)); 2316 } 2317 } catch (ReflectiveOperationException ex) { 2318 throw newInternalError(ex); 2319 } 2320 throw newInternalError("Unknown function index: " + idx); 2321 } 2322 }