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) { 666 if (n == 0) return; 667 } else if (av instanceof Object[]) { 668 int len = ((Object[])av).length; 669 if (len == n) return; 670 } else { 671 int len = java.lang.reflect.Array.getLength(av); 672 if (len == n) return; 673 } 674 // fall through to error: 675 throw newIllegalArgumentException("array is not of length "+n); 676 } 677 678 /** Factory method: Collect or filter selected argument(s). */ 679 static MethodHandle makeCollectArguments(MethodHandle target, 680 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) { 681 MethodType targetType = target.type(); // (a..., c, [b...])=>r 682 MethodType collectorType = collector.type(); // (b...)=>c 683 int collectArgCount = collectorType.parameterCount(); 684 Class<?> collectValType = collectorType.returnType(); 685 int collectValCount = (collectValType == void.class ? 0 : 1); 686 MethodType srcType = targetType // (a..., [b...])=>r 687 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount); 688 if (!retainOriginalArgs) { // (a..., b...)=>r 689 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterArray()); 690 } 691 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ] 692 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ] 693 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ] 694 695 // Now build a LambdaForm. 696 MethodType lambdaType = srcType.invokerType(); 697 Name[] names = arguments(2, lambdaType); 698 final int collectNamePos = names.length - 2; 699 final int targetNamePos = names.length - 1; 700 701 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount); 702 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs); 703 704 // Build argument array for the target. 705 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ]. 706 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ]. 707 Name[] targetArgs = new Name[targetType.parameterCount()]; 708 int inputArgPos = 1; // incoming LF args to copy to target 709 int targetArgPos = 0; // fill pointer for targetArgs 710 int chunk = collectArgPos; // |headArgs| 711 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 712 inputArgPos += chunk; 713 targetArgPos += chunk; 714 if (collectValType != void.class) { 715 targetArgs[targetArgPos++] = names[collectNamePos]; 716 } 717 chunk = collectArgCount; 718 if (retainOriginalArgs) { 719 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 720 targetArgPos += chunk; // optionally pass on the collected chunk 721 } 722 inputArgPos += chunk; 723 chunk = targetArgs.length - targetArgPos; // all the rest 724 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 725 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also 726 names[targetNamePos] = new Name(target, (Object[]) targetArgs); 727 728 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.COLLECT); 729 return SimpleMethodHandle.make(srcType, form); 730 } 731 732 @LambdaForm.Hidden 733 static 734 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) { 735 if (testResult) { 736 return target; 737 } else { 738 return fallback; 739 } 740 } 741 742 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies. 743 @LambdaForm.Hidden 744 @jdk.internal.HotSpotIntrinsicCandidate 745 static 746 boolean profileBoolean(boolean result, int[] counters) { 747 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively. 748 int idx = result ? 1 : 0; 749 try { 750 counters[idx] = Math.addExact(counters[idx], 1); 751 } catch (ArithmeticException e) { 752 // Avoid continuous overflow by halving the problematic count. 753 counters[idx] = counters[idx] / 2; 754 } 755 return result; 756 } 757 758 // Intrinsified by C2. Returns true if obj is a compile-time constant. 759 @LambdaForm.Hidden 760 @jdk.internal.HotSpotIntrinsicCandidate 761 static 762 boolean isCompileConstant(Object obj) { 763 return false; 764 } 765 766 static 767 MethodHandle makeGuardWithTest(MethodHandle test, 768 MethodHandle target, 769 MethodHandle fallback) { 770 MethodType type = target.type(); 771 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type)); 772 MethodType basicType = type.basicType(); 773 LambdaForm form = makeGuardWithTestForm(basicType); 774 BoundMethodHandle mh; 775 try { 776 if (PROFILE_GWT) { 777 int[] counts = new int[2]; 778 mh = (BoundMethodHandle) 779 BoundMethodHandle.speciesData_LLLL().constructor().invokeBasic(type, form, 780 (Object) test, (Object) profile(target), (Object) profile(fallback), counts); 781 } else { 782 mh = (BoundMethodHandle) 783 BoundMethodHandle.speciesData_LLL().constructor().invokeBasic(type, form, 784 (Object) test, (Object) profile(target), (Object) profile(fallback)); 785 } 786 } catch (Throwable ex) { 787 throw uncaughtException(ex); 788 } 789 assert(mh.type() == type); 790 return mh; 791 } 792 793 794 static 795 MethodHandle profile(MethodHandle target) { 796 if (DONT_INLINE_THRESHOLD >= 0) { 797 return makeBlockInliningWrapper(target); 798 } else { 799 return target; 800 } 801 } 802 803 /** 804 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times. 805 * Corresponding LambdaForm has @DontInline when compiled into bytecode. 806 */ 807 static 808 MethodHandle makeBlockInliningWrapper(MethodHandle target) { 809 LambdaForm lform; 810 if (DONT_INLINE_THRESHOLD > 0) { 811 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target); 812 } else { 813 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target); 814 } 815 return new CountingWrapper(target, lform, 816 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM, 817 DONT_INLINE_THRESHOLD); 818 } 819 820 private final static class Makers { 821 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */ 822 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() { 823 @Override 824 public LambdaForm apply(MethodHandle target) { 825 return DelegatingMethodHandle.makeReinvokerForm(target, 826 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, false, 827 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting); 828 } 829 }; 830 831 /** Constructs simple reinvoker lambda form for a particular method handle */ 832 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() { 833 @Override 834 public LambdaForm apply(MethodHandle target) { 835 return DelegatingMethodHandle.makeReinvokerForm(target, 836 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget); 837 } 838 }; 839 840 /** Maker of type-polymorphic varargs */ 841 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() { 842 @Override 843 protected MethodHandle[] computeValue(Class<?> type) { 844 return new MethodHandle[MAX_JVM_ARITY + 1]; 845 } 846 }; 847 } 848 849 /** 850 * Counting method handle. It has 2 states: counting and non-counting. 851 * It is in counting state for the first n invocations and then transitions to non-counting state. 852 * Behavior in counting and non-counting states is determined by lambda forms produced by 853 * countingFormProducer & nonCountingFormProducer respectively. 854 */ 855 static class CountingWrapper extends DelegatingMethodHandle { 856 private final MethodHandle target; 857 private int count; 858 private Function<MethodHandle, LambdaForm> countingFormProducer; 859 private Function<MethodHandle, LambdaForm> nonCountingFormProducer; 860 private volatile boolean isCounting; 861 862 private CountingWrapper(MethodHandle target, LambdaForm lform, 863 Function<MethodHandle, LambdaForm> countingFromProducer, 864 Function<MethodHandle, LambdaForm> nonCountingFormProducer, 865 int count) { 866 super(target.type(), lform); 867 this.target = target; 868 this.count = count; 869 this.countingFormProducer = countingFromProducer; 870 this.nonCountingFormProducer = nonCountingFormProducer; 871 this.isCounting = (count > 0); 872 } 873 874 @Hidden 875 @Override 876 protected MethodHandle getTarget() { 877 return target; 878 } 879 880 @Override 881 public MethodHandle asTypeUncached(MethodType newType) { 882 MethodHandle newTarget = target.asType(newType); 883 MethodHandle wrapper; 884 if (isCounting) { 885 LambdaForm lform; 886 lform = countingFormProducer.apply(newTarget); 887 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD); 888 } else { 889 wrapper = newTarget; // no need for a counting wrapper anymore 890 } 891 return (asTypeCache = wrapper); 892 } 893 894 // Customize target if counting happens for too long. 895 private int invocations = CUSTOMIZE_THRESHOLD; 896 private void maybeCustomizeTarget() { 897 int c = invocations; 898 if (c >= 0) { 899 if (c == 1) { 900 target.customize(); 901 } 902 invocations = c - 1; 903 } 904 } 905 906 boolean countDown() { 907 int c = count; 908 maybeCustomizeTarget(); 909 if (c <= 1) { 910 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility. 911 if (isCounting) { 912 isCounting = false; 913 return true; 914 } else { 915 return false; 916 } 917 } else { 918 count = c - 1; 919 return false; 920 } 921 } 922 923 @Hidden 924 static void maybeStopCounting(Object o1) { 925 CountingWrapper wrapper = (CountingWrapper) o1; 926 if (wrapper.countDown()) { 927 // Reached invocation threshold. Replace counting behavior with a non-counting one. 928 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target); 929 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition 930 wrapper.updateForm(lform); 931 } 932 } 933 934 static final NamedFunction NF_maybeStopCounting; 935 static { 936 Class<?> THIS_CLASS = CountingWrapper.class; 937 try { 938 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class)); 939 } catch (ReflectiveOperationException ex) { 940 throw newInternalError(ex); 941 } 942 } 943 } 944 945 static 946 LambdaForm makeGuardWithTestForm(MethodType basicType) { 947 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT); 948 if (lform != null) return lform; 949 final int THIS_MH = 0; // the BMH_LLL 950 final int ARG_BASE = 1; // start of incoming arguments 951 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 952 int nameCursor = ARG_LIMIT; 953 final int GET_TEST = nameCursor++; 954 final int GET_TARGET = nameCursor++; 955 final int GET_FALLBACK = nameCursor++; 956 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1; 957 final int CALL_TEST = nameCursor++; 958 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1; 959 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST 960 final int SELECT_ALT = nameCursor++; 961 final int CALL_TARGET = nameCursor++; 962 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative 963 964 MethodType lambdaType = basicType.invokerType(); 965 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 966 967 BoundMethodHandle.SpeciesData data = 968 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL() 969 : BoundMethodHandle.speciesData_LLL(); 970 names[THIS_MH] = names[THIS_MH].withConstraint(data); 971 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]); 972 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]); 973 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]); 974 if (GET_COUNTERS != -1) { 975 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]); 976 } 977 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class); 978 979 // call test 980 MethodType testType = basicType.changeReturnType(boolean.class).basicType(); 981 invokeArgs[0] = names[GET_TEST]; 982 names[CALL_TEST] = new Name(testType, invokeArgs); 983 984 // profile branch 985 if (PROFILE != -1) { 986 names[PROFILE] = new Name(getFunction(NF_profileBoolean), names[CALL_TEST], names[GET_COUNTERS]); 987 } 988 // call selectAlternative 989 names[SELECT_ALT] = new Name(new NamedFunction(getConstantHandle(MH_selectAlternative), Intrinsic.SELECT_ALTERNATIVE), names[TEST], names[GET_TARGET], names[GET_FALLBACK]); 990 991 // call target or fallback 992 invokeArgs[0] = names[SELECT_ALT]; 993 names[CALL_TARGET] = new Name(basicType, invokeArgs); 994 995 lform = new LambdaForm(lambdaType.parameterCount(), names, /*forceInline=*/true, Kind.GUARD); 996 997 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform); 998 } 999 1000 /** 1001 * The LambdaForm shape for catchException combinator is the following: 1002 * <blockquote><pre>{@code 1003 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{ 1004 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L); 1005 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L); 1006 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L); 1007 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L); 1008 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L); 1009 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L); 1010 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L); 1011 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I} 1012 * }</pre></blockquote> 1013 * 1014 * argL0 and argL2 are target and catcher method handles. argL1 is exception class. 1015 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[] 1016 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()). 1017 * 1018 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms 1019 * among catchException combinators with the same basic type. 1020 */ 1021 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) { 1022 MethodType lambdaType = basicType.invokerType(); 1023 1024 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC); 1025 if (lform != null) { 1026 return lform; 1027 } 1028 final int THIS_MH = 0; // the BMH_LLLLL 1029 final int ARG_BASE = 1; // start of incoming arguments 1030 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 1031 1032 int nameCursor = ARG_LIMIT; 1033 final int GET_TARGET = nameCursor++; 1034 final int GET_CLASS = nameCursor++; 1035 final int GET_CATCHER = nameCursor++; 1036 final int GET_COLLECT_ARGS = nameCursor++; 1037 final int GET_UNBOX_RESULT = nameCursor++; 1038 final int BOXED_ARGS = nameCursor++; 1039 final int TRY_CATCH = nameCursor++; 1040 final int UNBOX_RESULT = nameCursor++; 1041 1042 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 1043 1044 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL(); 1045 names[THIS_MH] = names[THIS_MH].withConstraint(data); 1046 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]); 1047 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]); 1048 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]); 1049 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]); 1050 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]); 1051 1052 // FIXME: rework argument boxing/result unboxing logic for LF interpretation 1053 1054 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 1055 MethodType collectArgsType = basicType.changeReturnType(Object.class); 1056 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 1057 Object[] args = new Object[invokeBasic.type().parameterCount()]; 1058 args[0] = names[GET_COLLECT_ARGS]; 1059 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE); 1060 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args); 1061 1062 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L); 1063 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]}; 1064 names[TRY_CATCH] = new Name(getFunction(NF_guardWithCatch), gwcArgs); 1065 1066 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 1067 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 1068 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]}; 1069 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 1070 1071 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.GUARD_WITH_CATCH); 1072 1073 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform); 1074 } 1075 1076 static 1077 MethodHandle makeGuardWithCatch(MethodHandle target, 1078 Class<? extends Throwable> exType, 1079 MethodHandle catcher) { 1080 MethodType type = target.type(); 1081 LambdaForm form = makeGuardWithCatchForm(type.basicType()); 1082 1083 // Prepare auxiliary method handles used during LambdaForm interpretation. 1084 // Box arguments and wrap them into Object[]: ValueConversions.array(). 1085 MethodType varargsType = type.changeReturnType(Object[].class); 1086 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 1087 MethodHandle unboxResult = unboxResultHandle(type.returnType()); 1088 1089 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL(); 1090 BoundMethodHandle mh; 1091 try { 1092 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) exType, 1093 (Object) catcher, (Object) collectArgs, (Object) unboxResult); 1094 } catch (Throwable ex) { 1095 throw uncaughtException(ex); 1096 } 1097 assert(mh.type() == type); 1098 return mh; 1099 } 1100 1101 /** 1102 * Intrinsified during LambdaForm compilation 1103 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}). 1104 */ 1105 @LambdaForm.Hidden 1106 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher, 1107 Object... av) throws Throwable { 1108 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case. 1109 try { 1110 return target.asFixedArity().invokeWithArguments(av); 1111 } catch (Throwable t) { 1112 if (!exType.isInstance(t)) throw t; 1113 return catcher.asFixedArity().invokeWithArguments(prepend(av, t)); 1114 } 1115 } 1116 1117 /** Prepend elements to an array. */ 1118 @LambdaForm.Hidden 1119 private static Object[] prepend(Object[] array, Object... elems) { 1120 int nArray = array.length; 1121 int nElems = elems.length; 1122 Object[] newArray = new Object[nArray + nElems]; 1123 System.arraycopy(elems, 0, newArray, 0, nElems); 1124 System.arraycopy(array, 0, newArray, nElems, nArray); 1125 return newArray; 1126 } 1127 1128 static 1129 MethodHandle throwException(MethodType type) { 1130 assert(Throwable.class.isAssignableFrom(type.parameterType(0))); 1131 int arity = type.parameterCount(); 1132 if (arity > 1) { 1133 MethodHandle mh = throwException(type.dropParameterTypes(1, arity)); 1134 mh = MethodHandles.dropArguments(mh, 1, Arrays.copyOfRange(type.parameterArray(), 1, arity)); 1135 return mh; 1136 } 1137 return makePairwiseConvert(getFunction(NF_throwException).resolvedHandle(), type, false, true); 1138 } 1139 1140 static <T extends Throwable> Empty throwException(T t) throws T { throw t; } 1141 1142 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2]; 1143 static MethodHandle fakeMethodHandleInvoke(MemberName method) { 1144 int idx; 1145 assert(method.isMethodHandleInvoke()); 1146 switch (method.getName()) { 1147 case "invoke": idx = 0; break; 1148 case "invokeExact": idx = 1; break; 1149 default: throw new InternalError(method.getName()); 1150 } 1151 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx]; 1152 if (mh != null) return mh; 1153 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class, 1154 MethodHandle.class, Object[].class); 1155 mh = throwException(type); 1156 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle")); 1157 if (!method.getInvocationType().equals(mh.type())) 1158 throw new InternalError(method.toString()); 1159 mh = mh.withInternalMemberName(method, false); 1160 mh = mh.withVarargs(true); 1161 assert(method.isVarargs()); 1162 FAKE_METHOD_HANDLE_INVOKE[idx] = mh; 1163 return mh; 1164 } 1165 static MethodHandle fakeVarHandleInvoke(MemberName method) { 1166 // TODO caching, is it necessary? 1167 MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class, 1168 VarHandle.class, Object[].class); 1169 MethodHandle mh = throwException(type); 1170 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle")); 1171 if (!method.getInvocationType().equals(mh.type())) 1172 throw new InternalError(method.toString()); 1173 mh = mh.withInternalMemberName(method, false); 1174 mh = mh.asVarargsCollector(Object[].class); 1175 assert(method.isVarargs()); 1176 return mh; 1177 } 1178 1179 /** 1180 * Create an alias for the method handle which, when called, 1181 * appears to be called from the same class loader and protection domain 1182 * as hostClass. 1183 * This is an expensive no-op unless the method which is called 1184 * is sensitive to its caller. A small number of system methods 1185 * are in this category, including Class.forName and Method.invoke. 1186 */ 1187 static 1188 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) { 1189 return BindCaller.bindCaller(mh, hostClass); 1190 } 1191 1192 // Put the whole mess into its own nested class. 1193 // That way we can lazily load the code and set up the constants. 1194 private static class BindCaller { 1195 private static MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class); 1196 1197 static 1198 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) { 1199 // Code in the boot layer should now be careful while creating method handles or 1200 // functional interface instances created from method references to @CallerSensitive methods, 1201 // it needs to be ensured the handles or interface instances are kept safe and are not passed 1202 // from the boot layer to untrusted code. 1203 if (hostClass == null 1204 || (hostClass.isArray() || 1205 hostClass.isPrimitive() || 1206 hostClass.getName().startsWith("java.lang.invoke."))) { 1207 throw new InternalError(); // does not happen, and should not anyway 1208 } 1209 // For simplicity, convert mh to a varargs-like method. 1210 MethodHandle vamh = prepareForInvoker(mh); 1211 // Cache the result of makeInjectedInvoker once per argument class. 1212 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass); 1213 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass); 1214 } 1215 1216 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) { 1217 try { 1218 Class<?> invokerClass = UNSAFE.defineAnonymousClass(hostClass, INJECTED_INVOKER_TEMPLATE, null); 1219 assert checkInjectedInvoker(hostClass, invokerClass); 1220 return IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT); 1221 } catch (ReflectiveOperationException ex) { 1222 throw uncaughtException(ex); 1223 } 1224 } 1225 1226 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() { 1227 @Override protected MethodHandle computeValue(Class<?> hostClass) { 1228 return makeInjectedInvoker(hostClass); 1229 } 1230 }; 1231 1232 // Adapt mh so that it can be called directly from an injected invoker: 1233 private static MethodHandle prepareForInvoker(MethodHandle mh) { 1234 mh = mh.asFixedArity(); 1235 MethodType mt = mh.type(); 1236 int arity = mt.parameterCount(); 1237 MethodHandle vamh = mh.asType(mt.generic()); 1238 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames 1239 vamh = vamh.asSpreader(Object[].class, arity); 1240 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames 1241 return vamh; 1242 } 1243 1244 // Undo the adapter effect of prepareForInvoker: 1245 private static MethodHandle restoreToType(MethodHandle vamh, 1246 MethodHandle original, 1247 Class<?> hostClass) { 1248 MethodType type = original.type(); 1249 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount()); 1250 MemberName member = original.internalMemberName(); 1251 mh = mh.asType(type); 1252 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass); 1253 return mh; 1254 } 1255 1256 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) { 1257 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)"; 1258 try { 1259 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)"; 1260 } catch (SecurityException ex) { 1261 // Self-check was blocked by security manager. This is OK. 1262 } 1263 try { 1264 // Test the invoker to ensure that it really injects into the right place. 1265 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT); 1266 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass); 1267 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass }); 1268 } catch (Throwable ex) { 1269 throw new InternalError(ex); 1270 } 1271 } 1272 1273 private static final MethodHandle MH_checkCallerClass; 1274 static { 1275 final Class<?> THIS_CLASS = BindCaller.class; 1276 assert(checkCallerClass(THIS_CLASS)); 1277 try { 1278 MH_checkCallerClass = IMPL_LOOKUP 1279 .findStatic(THIS_CLASS, "checkCallerClass", 1280 MethodType.methodType(boolean.class, Class.class)); 1281 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS)); 1282 } catch (Throwable ex) { 1283 throw new InternalError(ex); 1284 } 1285 } 1286 1287 @CallerSensitive 1288 @ForceInline // to ensure Reflection.getCallerClass optimization 1289 private static boolean checkCallerClass(Class<?> expected) { 1290 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here. 1291 Class<?> actual = Reflection.getCallerClass(); 1292 if (actual != expected) 1293 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName()); 1294 return true; 1295 } 1296 1297 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate(); 1298 1299 /** Produces byte code for a class that is used as an injected invoker. */ 1300 private static byte[] generateInvokerTemplate() { 1301 ClassWriter cw = new ClassWriter(0); 1302 1303 // private static class InjectedInvoker { 1304 // @Hidden 1305 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable { 1306 // return vamh.invokeExact(args); 1307 // } 1308 // } 1309 cw.visit(52, ACC_PRIVATE | ACC_SUPER, "InjectedInvoker", null, "java/lang/Object", null); 1310 1311 MethodVisitor mv = cw.visitMethod(ACC_STATIC, "invoke_V", 1312 "(Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;", 1313 null, null); 1314 1315 // Suppress invoker method in stack traces. 1316 AnnotationVisitor av0 = mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1317 av0.visitEnd(); 1318 1319 mv.visitCode(); 1320 mv.visitVarInsn(ALOAD, 0); 1321 mv.visitVarInsn(ALOAD, 1); 1322 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle", "invokeExact", 1323 "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1324 mv.visitInsn(ARETURN); 1325 mv.visitMaxs(2, 2); 1326 mv.visitEnd(); 1327 1328 cw.visitEnd(); 1329 return cw.toByteArray(); 1330 } 1331 } 1332 1333 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */ 1334 private static final class WrappedMember extends DelegatingMethodHandle { 1335 private final MethodHandle target; 1336 private final MemberName member; 1337 private final Class<?> callerClass; 1338 private final boolean isInvokeSpecial; 1339 1340 private WrappedMember(MethodHandle target, MethodType type, 1341 MemberName member, boolean isInvokeSpecial, 1342 Class<?> callerClass) { 1343 super(type, target); 1344 this.target = target; 1345 this.member = member; 1346 this.callerClass = callerClass; 1347 this.isInvokeSpecial = isInvokeSpecial; 1348 } 1349 1350 @Override 1351 MemberName internalMemberName() { 1352 return member; 1353 } 1354 @Override 1355 Class<?> internalCallerClass() { 1356 return callerClass; 1357 } 1358 @Override 1359 boolean isInvokeSpecial() { 1360 return isInvokeSpecial; 1361 } 1362 @Override 1363 protected MethodHandle getTarget() { 1364 return target; 1365 } 1366 @Override 1367 public MethodHandle asTypeUncached(MethodType newType) { 1368 // This MH is an alias for target, except for the MemberName 1369 // Drop the MemberName if there is any conversion. 1370 return asTypeCache = target.asType(newType); 1371 } 1372 } 1373 1374 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) { 1375 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial()) 1376 return target; 1377 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null); 1378 } 1379 1380 /** Intrinsic IDs */ 1381 /*non-public*/ 1382 enum Intrinsic { 1383 SELECT_ALTERNATIVE, 1384 GUARD_WITH_CATCH, 1385 TRY_FINALLY, 1386 LOOP, 1387 NEW_ARRAY, 1388 ARRAY_LOAD, 1389 ARRAY_STORE, 1390 ARRAY_LENGTH, 1391 IDENTITY, 1392 ZERO, 1393 NONE // no intrinsic associated 1394 } 1395 1396 /** Mark arbitrary method handle as intrinsic. 1397 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */ 1398 static final class IntrinsicMethodHandle extends DelegatingMethodHandle { 1399 private final MethodHandle target; 1400 private final Intrinsic intrinsicName; 1401 1402 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) { 1403 super(target.type(), target); 1404 this.target = target; 1405 this.intrinsicName = intrinsicName; 1406 } 1407 1408 @Override 1409 protected MethodHandle getTarget() { 1410 return target; 1411 } 1412 1413 @Override 1414 Intrinsic intrinsicName() { 1415 return intrinsicName; 1416 } 1417 1418 @Override 1419 public MethodHandle asTypeUncached(MethodType newType) { 1420 // This MH is an alias for target, except for the intrinsic name 1421 // Drop the name if there is any conversion. 1422 return asTypeCache = target.asType(newType); 1423 } 1424 1425 @Override 1426 String internalProperties() { 1427 return super.internalProperties() + 1428 "\n& Intrinsic="+intrinsicName; 1429 } 1430 1431 @Override 1432 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) { 1433 if (intrinsicName == Intrinsic.IDENTITY) { 1434 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength); 1435 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength); 1436 return newArray.asType(resultType); 1437 } 1438 return super.asCollector(arrayType, arrayLength); 1439 } 1440 } 1441 1442 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) { 1443 if (intrinsicName == target.intrinsicName()) 1444 return target; 1445 return new IntrinsicMethodHandle(target, intrinsicName); 1446 } 1447 1448 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) { 1449 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName); 1450 } 1451 1452 /// Collection of multiple arguments. 1453 1454 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) { 1455 MethodType type = MethodType.genericMethodType(nargs) 1456 .changeReturnType(rtype) 1457 .insertParameterTypes(0, ptypes); 1458 try { 1459 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type); 1460 } catch (ReflectiveOperationException ex) { 1461 return null; 1462 } 1463 } 1464 1465 private static final Object[] NO_ARGS_ARRAY = {}; 1466 private static Object[] makeArray(Object... args) { return args; } 1467 private static Object[] array() { return NO_ARGS_ARRAY; } 1468 private static Object[] array(Object a0) 1469 { return makeArray(a0); } 1470 private static Object[] array(Object a0, Object a1) 1471 { return makeArray(a0, a1); } 1472 private static Object[] array(Object a0, Object a1, Object a2) 1473 { return makeArray(a0, a1, a2); } 1474 private static Object[] array(Object a0, Object a1, Object a2, Object a3) 1475 { return makeArray(a0, a1, a2, a3); } 1476 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1477 Object a4) 1478 { return makeArray(a0, a1, a2, a3, a4); } 1479 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1480 Object a4, Object a5) 1481 { return makeArray(a0, a1, a2, a3, a4, a5); } 1482 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1483 Object a4, Object a5, Object a6) 1484 { return makeArray(a0, a1, a2, a3, a4, a5, a6); } 1485 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1486 Object a4, Object a5, Object a6, Object a7) 1487 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); } 1488 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1489 Object a4, Object a5, Object a6, Object a7, 1490 Object a8) 1491 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); } 1492 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1493 Object a4, Object a5, Object a6, Object a7, 1494 Object a8, Object a9) 1495 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); } 1496 1497 private static final int ARRAYS_COUNT = 11; 1498 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1]; 1499 1500 // filling versions of the above: 1501 // using Integer len instead of int len and no varargs to avoid bootstrapping problems 1502 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) { 1503 Object[] a = new Object[len]; 1504 fillWithArguments(a, 0, args); 1505 return a; 1506 } 1507 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) { 1508 Object[] a = Arrays.copyOf(example, len); 1509 assert(a.getClass() != Object[].class); 1510 fillWithArguments(a, 0, args); 1511 return a; 1512 } 1513 private static void fillWithArguments(Object[] a, int pos, Object... args) { 1514 System.arraycopy(args, 0, a, pos, args.length); 1515 } 1516 // using Integer pos instead of int pos to avoid bootstrapping problems 1517 private static Object[] fillArray(Integer pos, Object[] a, Object a0) 1518 { fillWithArguments(a, pos, a0); return a; } 1519 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1) 1520 { fillWithArguments(a, pos, a0, a1); return a; } 1521 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2) 1522 { fillWithArguments(a, pos, a0, a1, a2); return a; } 1523 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3) 1524 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; } 1525 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1526 Object a4) 1527 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; } 1528 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1529 Object a4, Object a5) 1530 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; } 1531 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1532 Object a4, Object a5, Object a6) 1533 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; } 1534 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1535 Object a4, Object a5, Object a6, Object a7) 1536 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; } 1537 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1538 Object a4, Object a5, Object a6, Object a7, 1539 Object a8) 1540 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; } 1541 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1542 Object a4, Object a5, Object a6, Object a7, 1543 Object a8, Object a9) 1544 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; } 1545 1546 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods 1547 private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT]; 1548 1549 private static MethodHandle getFillArray(int count) { 1550 assert (count > 0 && count < FILL_ARRAYS_COUNT); 1551 MethodHandle mh = FILL_ARRAYS[count]; 1552 if (mh != null) { 1553 return mh; 1554 } 1555 mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class); 1556 FILL_ARRAYS[count] = mh; 1557 return mh; 1558 } 1559 1560 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) { 1561 Object a = w.makeArray(boxes.length); 1562 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length); 1563 return a; 1564 } 1565 1566 /** Return a method handle that takes the indicated number of Object 1567 * arguments and returns an Object array of them, as if for varargs. 1568 */ 1569 static MethodHandle varargsArray(int nargs) { 1570 MethodHandle mh = ARRAYS[nargs]; 1571 if (mh != null) { 1572 return mh; 1573 } 1574 if (nargs < ARRAYS_COUNT) { 1575 mh = findCollector("array", nargs, Object[].class); 1576 } else { 1577 mh = buildVarargsArray(getConstantHandle(MH_fillNewArray), 1578 getConstantHandle(MH_arrayIdentity), nargs); 1579 } 1580 assert(assertCorrectArity(mh, nargs)); 1581 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY); 1582 return ARRAYS[nargs] = mh; 1583 } 1584 1585 private static boolean assertCorrectArity(MethodHandle mh, int arity) { 1586 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh; 1587 return true; 1588 } 1589 1590 // Array identity function (used as getConstantHandle(MH_arrayIdentity)). 1591 static <T> T[] identity(T[] x) { 1592 return x; 1593 } 1594 1595 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) { 1596 // Build up the result mh as a sequence of fills like this: 1597 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23)) 1598 // The various fill(_,10*I,___*[J]) are reusable. 1599 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately 1600 int rightLen = nargs - leftLen; 1601 MethodHandle leftCollector = newArray.bindTo(nargs); 1602 leftCollector = leftCollector.asCollector(Object[].class, leftLen); 1603 MethodHandle mh = finisher; 1604 if (rightLen > 0) { 1605 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen); 1606 if (mh.equals(getConstantHandle(MH_arrayIdentity))) 1607 mh = rightFiller; 1608 else 1609 mh = MethodHandles.collectArguments(mh, 0, rightFiller); 1610 } 1611 if (mh.equals(getConstantHandle(MH_arrayIdentity))) 1612 mh = leftCollector; 1613 else 1614 mh = MethodHandles.collectArguments(mh, 0, leftCollector); 1615 return mh; 1616 } 1617 1618 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1; 1619 private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1]; 1620 /** fill_array_to_right(N).invoke(a, argL..arg[N-1]) 1621 * fills a[L]..a[N-1] with corresponding arguments, 1622 * and then returns a. The value L is a global constant (LEFT_ARGS). 1623 */ 1624 private static MethodHandle fillToRight(int nargs) { 1625 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs]; 1626 if (filler != null) return filler; 1627 filler = buildFiller(nargs); 1628 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1)); 1629 return FILL_ARRAY_TO_RIGHT[nargs] = filler; 1630 } 1631 private static MethodHandle buildFiller(int nargs) { 1632 if (nargs <= LEFT_ARGS) 1633 return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged 1634 // we need room for both mh and a in mh.invoke(a, arg*[nargs]) 1635 final int CHUNK = LEFT_ARGS; 1636 int rightLen = nargs % CHUNK; 1637 int midLen = nargs - rightLen; 1638 if (rightLen == 0) { 1639 midLen = nargs - (rightLen = CHUNK); 1640 if (FILL_ARRAY_TO_RIGHT[midLen] == null) { 1641 // build some precursors from left to right 1642 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK) 1643 if (j > LEFT_ARGS) fillToRight(j); 1644 } 1645 } 1646 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS); 1647 assert(rightLen > 0); 1648 MethodHandle midFill = fillToRight(midLen); // recursive fill 1649 MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1] 1650 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS); 1651 assert(rightFill.type().parameterCount() == 1 + rightLen); 1652 1653 // Combine the two fills: 1654 // right(mid(a, x10..x19), x20..x23) 1655 // The final product will look like this: 1656 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23) 1657 if (midLen == LEFT_ARGS) 1658 return rightFill; 1659 else 1660 return MethodHandles.collectArguments(rightFill, 0, midFill); 1661 } 1662 1663 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM 1664 1665 /** Return a method handle that takes the indicated number of 1666 * typed arguments and returns an array of them. 1667 * The type argument is the array type. 1668 */ 1669 static MethodHandle varargsArray(Class<?> arrayType, int nargs) { 1670 Class<?> elemType = arrayType.getComponentType(); 1671 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType); 1672 // FIXME: Need more special casing and caching here. 1673 if (nargs >= MAX_JVM_ARITY/2 - 1) { 1674 int slots = nargs; 1675 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH 1676 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive()) 1677 slots *= Wrapper.forPrimitiveType(elemType).stackSlots(); 1678 if (slots > MAX_ARRAY_SLOTS) 1679 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs); 1680 } 1681 if (elemType == Object.class) 1682 return varargsArray(nargs); 1683 // other cases: primitive arrays, subtypes of Object[] 1684 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType); 1685 MethodHandle mh = nargs < cache.length ? cache[nargs] : null; 1686 if (mh != null) return mh; 1687 if (nargs == 0) { 1688 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0); 1689 mh = MethodHandles.constant(arrayType, example); 1690 } else if (elemType.isPrimitive()) { 1691 MethodHandle builder = getConstantHandle(MH_fillNewArray); 1692 MethodHandle producer = buildArrayProducer(arrayType); 1693 mh = buildVarargsArray(builder, producer, nargs); 1694 } else { 1695 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class); 1696 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType); 1697 MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example); 1698 MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed 1699 mh = buildVarargsArray(builder, producer, nargs); 1700 } 1701 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType))); 1702 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY); 1703 assert(assertCorrectArity(mh, nargs)); 1704 if (nargs < cache.length) 1705 cache[nargs] = mh; 1706 return mh; 1707 } 1708 1709 private static MethodHandle buildArrayProducer(Class<?> arrayType) { 1710 Class<?> elemType = arrayType.getComponentType(); 1711 assert(elemType.isPrimitive()); 1712 return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType)); 1713 } 1714 1715 /*non-public*/ static void assertSame(Object mh1, Object mh2) { 1716 if (mh1 != mh2) { 1717 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)", 1718 mh1, ((MethodHandle)mh1).form, 1719 mh2, ((MethodHandle)mh2).form); 1720 throw newInternalError(msg); 1721 } 1722 } 1723 1724 // Local constant functions: 1725 1726 /* non-public */ 1727 static final byte NF_checkSpreadArgument = 0, 1728 NF_guardWithCatch = 1, 1729 NF_throwException = 2, 1730 NF_tryFinally = 3, 1731 NF_loop = 4, 1732 NF_profileBoolean = 5, 1733 NF_LIMIT = 6; 1734 1735 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT]; 1736 1737 static NamedFunction getFunction(byte func) { 1738 NamedFunction nf = NFS[func]; 1739 if (nf != null) { 1740 return nf; 1741 } 1742 return NFS[func] = createFunction(func); 1743 } 1744 1745 private static NamedFunction createFunction(byte func) { 1746 try { 1747 switch (func) { 1748 case NF_checkSpreadArgument: 1749 return new NamedFunction(MethodHandleImpl.class 1750 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class)); 1751 case NF_guardWithCatch: 1752 return new NamedFunction(MethodHandleImpl.class 1753 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class, 1754 MethodHandle.class, Object[].class)); 1755 case NF_tryFinally: 1756 return new NamedFunction(MethodHandleImpl.class 1757 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class)); 1758 case NF_loop: 1759 return new NamedFunction(MethodHandleImpl.class 1760 .getDeclaredMethod("loop", BasicType[].class, LoopClauses.class, Object[].class)); 1761 case NF_throwException: 1762 return new NamedFunction(MethodHandleImpl.class 1763 .getDeclaredMethod("throwException", Throwable.class)); 1764 case NF_profileBoolean: 1765 return new NamedFunction(MethodHandleImpl.class 1766 .getDeclaredMethod("profileBoolean", boolean.class, int[].class)); 1767 default: 1768 throw new InternalError("Undefined function: " + func); 1769 } 1770 } catch (ReflectiveOperationException ex) { 1771 throw newInternalError(ex); 1772 } 1773 } 1774 1775 static { 1776 SharedSecrets.setJavaLangInvokeAccess(new JavaLangInvokeAccess() { 1777 @Override 1778 public Object newMemberName() { 1779 return new MemberName(); 1780 } 1781 1782 @Override 1783 public String getName(Object mname) { 1784 MemberName memberName = (MemberName)mname; 1785 return memberName.getName(); 1786 } 1787 1788 @Override 1789 public MethodType getMethodType(Object mname) { 1790 MemberName memberName = (MemberName)mname; 1791 return memberName.getMethodType(); 1792 } 1793 1794 @Override 1795 public String getMethodDescriptor(Object mname) { 1796 MemberName memberName = (MemberName)mname; 1797 return memberName.getMethodDescriptor(); 1798 } 1799 1800 @Override 1801 public boolean isNative(Object mname) { 1802 MemberName memberName = (MemberName)mname; 1803 return memberName.isNative(); 1804 } 1805 1806 @Override 1807 public byte[] generateDirectMethodHandleHolderClassBytes( 1808 String className, MethodType[] methodTypes, int[] types) { 1809 return GenerateJLIClassesHelper 1810 .generateDirectMethodHandleHolderClassBytes( 1811 className, methodTypes, types); 1812 } 1813 1814 @Override 1815 public byte[] generateDelegatingMethodHandleHolderClassBytes( 1816 String className, MethodType[] methodTypes) { 1817 return GenerateJLIClassesHelper 1818 .generateDelegatingMethodHandleHolderClassBytes( 1819 className, methodTypes); 1820 } 1821 1822 @Override 1823 public Map.Entry<String, byte[]> generateConcreteBMHClassBytes( 1824 final String types) { 1825 return GenerateJLIClassesHelper 1826 .generateConcreteBMHClassBytes(types); 1827 } 1828 1829 @Override 1830 public byte[] generateBasicFormsClassBytes(final String className) { 1831 return GenerateJLIClassesHelper 1832 .generateBasicFormsClassBytes(className); 1833 } 1834 1835 @Override 1836 public byte[] generateInvokersHolderClassBytes(final String className, 1837 MethodType[] methodTypes) { 1838 return GenerateJLIClassesHelper 1839 .generateInvokersHolderClassBytes(className, methodTypes); 1840 } 1841 }); 1842 } 1843 1844 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */ 1845 private static MethodHandle unboxResultHandle(Class<?> returnType) { 1846 if (returnType.isPrimitive()) { 1847 if (returnType == void.class) { 1848 return ValueConversions.ignore(); 1849 } else { 1850 Wrapper w = Wrapper.forPrimitiveType(returnType); 1851 return ValueConversions.unboxExact(w); 1852 } 1853 } else { 1854 return MethodHandles.identity(Object.class); 1855 } 1856 } 1857 1858 /** 1859 * Assembles a loop method handle from the given handles and type information. 1860 * 1861 * @param tloop the return type of the loop. 1862 * @param targs types of the arguments to be passed to the loop. 1863 * @param init sanitized array of initializers for loop-local variables. 1864 * @param step sanitited array of loop bodies. 1865 * @param pred sanitized array of predicates. 1866 * @param fini sanitized array of loop finalizers. 1867 * 1868 * @return a handle that, when invoked, will execute the loop. 1869 */ 1870 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step, 1871 List<MethodHandle> pred, List<MethodHandle> fini) { 1872 MethodType type = MethodType.methodType(tloop, targs); 1873 BasicType[] initClauseTypes = 1874 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new); 1875 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes); 1876 1877 // Prepare auxiliary method handles used during LambdaForm interpretation. 1878 // Box arguments and wrap them into Object[]: ValueConversions.array(). 1879 MethodType varargsType = type.changeReturnType(Object[].class); 1880 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 1881 MethodHandle unboxResult = unboxResultHandle(tloop); 1882 1883 LoopClauses clauseData = 1884 new LoopClauses(new MethodHandle[][]{toArray(init), toArray(step), toArray(pred), toArray(fini)}); 1885 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL(); 1886 BoundMethodHandle mh; 1887 try { 1888 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) clauseData, 1889 (Object) collectArgs, (Object) unboxResult); 1890 } catch (Throwable ex) { 1891 throw uncaughtException(ex); 1892 } 1893 assert(mh.type() == type); 1894 return mh; 1895 } 1896 1897 private static MethodHandle[] toArray(List<MethodHandle> l) { 1898 return l.toArray(new MethodHandle[0]); 1899 } 1900 1901 /** 1902 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are 1903 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one 1904 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by 1905 * {@code t12}): 1906 * <blockquote><pre>{@code 1907 * loop=Lambda(a0:L,a1:L)=>{ 1908 * t2:L=BoundMethodHandle$Species_L3.argL0(a0:L); // LoopClauses holding init, step, pred, fini handles 1909 * t3:L=BoundMethodHandle$Species_L3.argL1(a0:L); // helper handle to box the arguments into an Object[] 1910 * t4:L=BoundMethodHandle$Species_L3.argL2(a0:L); // helper handle to unbox the result 1911 * t5:L=MethodHandle.invokeBasic(t3:L,a1:L); // box the arguments into an Object[] 1912 * t6:L=MethodHandleImpl.loop(null,t2:L,t3:L); // call the loop executor 1913 * t7:L=MethodHandle.invokeBasic(t4:L,t6:L);t7:L} // unbox the result; return the result 1914 * }</pre></blockquote> 1915 * <p> 1916 * {@code argL0} is a LoopClauses instance holding, in a 2-dimensional array, the init, step, pred, and fini method 1917 * handles. {@code argL1} and {@code argL2} are auxiliary method handles: {@code argL1} boxes arguments and wraps 1918 * them into {@code Object[]} ({@code ValueConversions.array()}), and {@code argL2} unboxes the result if necessary 1919 * ({@code ValueConversions.unbox()}). 1920 * <p> 1921 * Having {@code t3} and {@code t4} passed in via a BMH and not hardcoded in the lambda form allows to share lambda 1922 * forms among loop combinators with the same basic type. 1923 * <p> 1924 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to 1925 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is 1926 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int) 1927 * bytecode generation}. 1928 */ 1929 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) { 1930 MethodType lambdaType = basicType.invokerType(); 1931 1932 final int THIS_MH = 0; // the BMH_LLL 1933 final int ARG_BASE = 1; // start of incoming arguments 1934 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 1935 1936 int nameCursor = ARG_LIMIT; 1937 final int GET_CLAUSE_DATA = nameCursor++; 1938 final int GET_COLLECT_ARGS = nameCursor++; 1939 final int GET_UNBOX_RESULT = nameCursor++; 1940 final int BOXED_ARGS = nameCursor++; 1941 final int LOOP = nameCursor++; 1942 final int UNBOX_RESULT = nameCursor++; 1943 1944 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP); 1945 if (lform == null) { 1946 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 1947 1948 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL(); 1949 names[THIS_MH] = names[THIS_MH].withConstraint(data); 1950 names[GET_CLAUSE_DATA] = new Name(data.getterFunction(0), names[THIS_MH]); 1951 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(1), names[THIS_MH]); 1952 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(2), names[THIS_MH]); 1953 1954 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 1955 MethodType collectArgsType = basicType.changeReturnType(Object.class); 1956 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 1957 Object[] args = new Object[invokeBasic.type().parameterCount()]; 1958 args[0] = names[GET_COLLECT_ARGS]; 1959 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE); 1960 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.LOOP), args); 1961 1962 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,clauses:L,t_{i}:L); 1963 Object[] lArgs = 1964 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor 1965 names[GET_CLAUSE_DATA], names[BOXED_ARGS]}; 1966 names[LOOP] = new Name(getFunction(NF_loop), lArgs); 1967 1968 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 1969 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 1970 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]}; 1971 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 1972 1973 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP, 1974 new LambdaForm(lambdaType.parameterCount(), names, Kind.LOOP)); 1975 } 1976 1977 // BOXED_ARGS is the index into the names array where the loop idiom starts 1978 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes); 1979 } 1980 1981 static class LoopClauses { 1982 @Stable final MethodHandle[][] clauses; 1983 LoopClauses(MethodHandle[][] clauses) { 1984 assert clauses.length == 4; 1985 this.clauses = clauses; 1986 } 1987 @Override 1988 public String toString() { 1989 StringBuffer sb = new StringBuffer("LoopClauses -- "); 1990 for (int i = 0; i < 4; ++i) { 1991 if (i > 0) { 1992 sb.append(" "); 1993 } 1994 sb.append('<').append(i).append(">: "); 1995 MethodHandle[] hs = clauses[i]; 1996 for (int j = 0; j < hs.length; ++j) { 1997 if (j > 0) { 1998 sb.append(" "); 1999 } 2000 sb.append('*').append(j).append(": ").append(hs[j]).append('\n'); 2001 } 2002 } 2003 sb.append(" --\n"); 2004 return sb.toString(); 2005 } 2006 } 2007 2008 /** 2009 * Intrinsified during LambdaForm compilation 2010 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}). 2011 */ 2012 @LambdaForm.Hidden 2013 static Object loop(BasicType[] localTypes, LoopClauses clauseData, Object... av) throws Throwable { 2014 final MethodHandle[] init = clauseData.clauses[0]; 2015 final MethodHandle[] step = clauseData.clauses[1]; 2016 final MethodHandle[] pred = clauseData.clauses[2]; 2017 final MethodHandle[] fini = clauseData.clauses[3]; 2018 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count(); 2019 int nArgs = init[0].type().parameterCount(); 2020 Object[] varsAndArgs = new Object[varSize + nArgs]; 2021 for (int i = 0, v = 0; i < init.length; ++i) { 2022 MethodHandle ih = init[i]; 2023 if (ih.type().returnType() == void.class) { 2024 ih.invokeWithArguments(av); 2025 } else { 2026 varsAndArgs[v++] = ih.invokeWithArguments(av); 2027 } 2028 } 2029 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs); 2030 final int nSteps = step.length; 2031 for (; ; ) { 2032 for (int i = 0, v = 0; i < nSteps; ++i) { 2033 MethodHandle p = pred[i]; 2034 MethodHandle s = step[i]; 2035 MethodHandle f = fini[i]; 2036 if (s.type().returnType() == void.class) { 2037 s.invokeWithArguments(varsAndArgs); 2038 } else { 2039 varsAndArgs[v++] = s.invokeWithArguments(varsAndArgs); 2040 } 2041 if (!(boolean) p.invokeWithArguments(varsAndArgs)) { 2042 return f.invokeWithArguments(varsAndArgs); 2043 } 2044 } 2045 } 2046 } 2047 2048 /** 2049 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, 2050 * MethodHandle) counting loops}. 2051 * 2052 * @param limit the upper bound of the parameter, statically bound at loop creation time. 2053 * @param counter the counter parameter, passed in during loop execution. 2054 * 2055 * @return whether the counter has reached the limit. 2056 */ 2057 static boolean countedLoopPredicate(int limit, int counter) { 2058 return counter < limit; 2059 } 2060 2061 /** 2062 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, 2063 * MethodHandle) counting loops} to increment the counter. 2064 * 2065 * @param limit the upper bound of the loop counter (ignored). 2066 * @param counter the loop counter. 2067 * 2068 * @return the loop counter incremented by 1. 2069 */ 2070 static int countedLoopStep(int limit, int counter) { 2071 return counter + 1; 2072 } 2073 2074 /** 2075 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}. 2076 * 2077 * @param it the {@link Iterable} over which the loop iterates. 2078 * 2079 * @return an {@link Iterator} over the argument's elements. 2080 */ 2081 static Iterator<?> initIterator(Iterable<?> it) { 2082 return it.iterator(); 2083 } 2084 2085 /** 2086 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}. 2087 * 2088 * @param it the iterator to be checked. 2089 * 2090 * @return {@code true} iff there are more elements to iterate over. 2091 */ 2092 static boolean iteratePredicate(Iterator<?> it) { 2093 return it.hasNext(); 2094 } 2095 2096 /** 2097 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain 2098 * MethodHandles#iteratedLoop iterating loops}. 2099 * 2100 * @param it the iterator. 2101 * 2102 * @return the next element from the iterator. 2103 */ 2104 static Object iterateNext(Iterator<?> it) { 2105 return it.next(); 2106 } 2107 2108 /** 2109 * Makes a {@code try-finally} handle that conforms to the type constraints. 2110 * 2111 * @param target the target to execute in a {@code try-finally} block. 2112 * @param cleanup the cleanup to execute in the {@code finally} block. 2113 * @param rtype the result type of the entire construct. 2114 * @param argTypes the types of the arguments. 2115 * 2116 * @return a handle on the constructed {@code try-finally} block. 2117 */ 2118 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, List<Class<?>> argTypes) { 2119 MethodType type = MethodType.methodType(rtype, argTypes); 2120 LambdaForm form = makeTryFinallyForm(type.basicType()); 2121 2122 // Prepare auxiliary method handles used during LambdaForm interpretation. 2123 // Box arguments and wrap them into Object[]: ValueConversions.array(). 2124 MethodType varargsType = type.changeReturnType(Object[].class); 2125 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 2126 MethodHandle unboxResult = unboxResultHandle(rtype); 2127 2128 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL(); 2129 BoundMethodHandle mh; 2130 try { 2131 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) cleanup, 2132 (Object) collectArgs, (Object) unboxResult); 2133 } catch (Throwable ex) { 2134 throw uncaughtException(ex); 2135 } 2136 assert(mh.type() == type); 2137 return mh; 2138 } 2139 2140 /** 2141 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in 2142 * {@code a1}, and a reference return type, with the return value represented by {@code t8}): 2143 * <blockquote><pre>{@code 2144 * tryFinally=Lambda(a0:L,a1:L)=>{ 2145 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle 2146 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle 2147 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[] 2148 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result 2149 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[] 2150 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor 2151 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result 2152 * }</pre></blockquote> 2153 * <p> 2154 * {@code argL0} and {@code argL1} are the target and cleanup method handles. 2155 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into 2156 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary 2157 * ({@code ValueConversions.unbox()}). 2158 * <p> 2159 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda 2160 * forms among tryFinally combinators with the same basic type. 2161 */ 2162 private static LambdaForm makeTryFinallyForm(MethodType basicType) { 2163 MethodType lambdaType = basicType.invokerType(); 2164 2165 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF); 2166 if (lform != null) { 2167 return lform; 2168 } 2169 final int THIS_MH = 0; // the BMH_LLLL 2170 final int ARG_BASE = 1; // start of incoming arguments 2171 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 2172 2173 int nameCursor = ARG_LIMIT; 2174 final int GET_TARGET = nameCursor++; 2175 final int GET_CLEANUP = nameCursor++; 2176 final int GET_COLLECT_ARGS = nameCursor++; 2177 final int GET_UNBOX_RESULT = nameCursor++; 2178 final int BOXED_ARGS = nameCursor++; 2179 final int TRY_FINALLY = nameCursor++; 2180 final int UNBOX_RESULT = nameCursor++; 2181 2182 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 2183 2184 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL(); 2185 names[THIS_MH] = names[THIS_MH].withConstraint(data); 2186 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]); 2187 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]); 2188 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]); 2189 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]); 2190 2191 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 2192 MethodType collectArgsType = basicType.changeReturnType(Object.class); 2193 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 2194 Object[] args = new Object[invokeBasic.type().parameterCount()]; 2195 args[0] = names[GET_COLLECT_ARGS]; 2196 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE); 2197 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.TRY_FINALLY), args); 2198 2199 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L); 2200 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]}; 2201 names[TRY_FINALLY] = new Name(getFunction(NF_tryFinally), tfArgs); 2202 2203 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 2204 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 2205 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]}; 2206 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 2207 2208 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.TRY_FINALLY); 2209 2210 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform); 2211 } 2212 2213 /** 2214 * Intrinsified during LambdaForm compilation 2215 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}). 2216 */ 2217 @LambdaForm.Hidden 2218 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable { 2219 Throwable t = null; 2220 Object r = null; 2221 try { 2222 r = target.invokeWithArguments(av); 2223 } catch (Throwable thrown) { 2224 t = thrown; 2225 throw t; 2226 } finally { 2227 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r); 2228 r = cleanup.invokeWithArguments(args); 2229 } 2230 return r; 2231 } 2232 2233 // Indexes into constant method handles: 2234 static final int 2235 MH_cast = 0, 2236 MH_selectAlternative = 1, 2237 MH_copyAsPrimitiveArray = 2, 2238 MH_fillNewTypedArray = 3, 2239 MH_fillNewArray = 4, 2240 MH_arrayIdentity = 5, 2241 MH_countedLoopPred = 6, 2242 MH_countedLoopStep = 7, 2243 MH_initIterator = 8, 2244 MH_iteratePred = 9, 2245 MH_iterateNext = 10, 2246 MH_Array_newInstance = 11, 2247 MH_LIMIT = 12; 2248 2249 static MethodHandle getConstantHandle(int idx) { 2250 MethodHandle handle = HANDLES[idx]; 2251 if (handle != null) { 2252 return handle; 2253 } 2254 return setCachedHandle(idx, makeConstantHandle(idx)); 2255 } 2256 2257 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) { 2258 // Simulate a CAS, to avoid racy duplication of results. 2259 MethodHandle prev = HANDLES[idx]; 2260 if (prev != null) { 2261 return prev; 2262 } 2263 HANDLES[idx] = method; 2264 return method; 2265 } 2266 2267 // Local constant method handles: 2268 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT]; 2269 2270 private static MethodHandle makeConstantHandle(int idx) { 2271 try { 2272 switch (idx) { 2273 case MH_cast: 2274 return IMPL_LOOKUP.findVirtual(Class.class, "cast", 2275 MethodType.methodType(Object.class, Object.class)); 2276 case MH_copyAsPrimitiveArray: 2277 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray", 2278 MethodType.methodType(Object.class, Wrapper.class, Object[].class)); 2279 case MH_arrayIdentity: 2280 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity", 2281 MethodType.methodType(Object[].class, Object[].class)); 2282 case MH_fillNewArray: 2283 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray", 2284 MethodType.methodType(Object[].class, Integer.class, Object[].class)); 2285 case MH_fillNewTypedArray: 2286 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray", 2287 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class)); 2288 case MH_selectAlternative: 2289 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative", 2290 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class)); 2291 case MH_countedLoopPred: 2292 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate", 2293 MethodType.methodType(boolean.class, int.class, int.class)); 2294 case MH_countedLoopStep: 2295 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep", 2296 MethodType.methodType(int.class, int.class, int.class)); 2297 case MH_initIterator: 2298 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator", 2299 MethodType.methodType(Iterator.class, Iterable.class)); 2300 case MH_iteratePred: 2301 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate", 2302 MethodType.methodType(boolean.class, Iterator.class)); 2303 case MH_iterateNext: 2304 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext", 2305 MethodType.methodType(Object.class, Iterator.class)); 2306 case MH_Array_newInstance: 2307 return IMPL_LOOKUP.findStatic(Array.class, "newInstance", 2308 MethodType.methodType(Object.class, Class.class, int.class)); 2309 } 2310 } catch (ReflectiveOperationException ex) { 2311 throw newInternalError(ex); 2312 } 2313 throw newInternalError("Unknown function index: " + idx); 2314 } 2315 }