1 /* 2 * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 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("convert", lambdaType.parameterCount(), names, RESULT); 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 asTypeUncached(MethodType newType) { 528 MethodType type = this.type(); 529 int collectArg = type.parameterCount() - 1; 530 int newArity = newType.parameterCount(); 531 if (newArity == collectArg+1 && 532 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) { 533 // if arity and trailing parameter are compatible, do normal thing 534 return asTypeCache = asFixedArity().asType(newType); 535 } 536 // check cache 537 MethodHandle acc = asCollectorCache; 538 if (acc != null && acc.type().parameterCount() == newArity) 539 return asTypeCache = acc.asType(newType); 540 // build and cache a collector 541 int arrayLength = newArity - collectArg; 542 MethodHandle collector; 543 try { 544 collector = asFixedArity().asCollector(arrayType, arrayLength); 545 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector; 546 } catch (IllegalArgumentException ex) { 547 throw new WrongMethodTypeException("cannot build collector", ex); 548 } 549 asCollectorCache = collector; 550 return asTypeCache = collector.asType(newType); 551 } 552 553 @Override 554 boolean viewAsTypeChecks(MethodType newType, boolean strict) { 555 super.viewAsTypeChecks(newType, true); 556 if (strict) return true; 557 // extra assertion for non-strict checks: 558 assert (type().lastParameterType().getComponentType() 559 .isAssignableFrom( 560 newType.lastParameterType().getComponentType())) 561 : Arrays.asList(this, newType); 562 return true; 563 } 564 } 565 566 /** Factory method: Spread selected argument. */ 567 static MethodHandle makeSpreadArguments(MethodHandle target, 568 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) { 569 MethodType targetType = target.type(); 570 571 for (int i = 0; i < spreadArgCount; i++) { 572 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i); 573 if (arg == null) arg = Object.class; 574 targetType = targetType.changeParameterType(spreadArgPos + i, arg); 575 } 576 target = target.asType(targetType); 577 578 MethodType srcType = targetType 579 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType); 580 // Now build a LambdaForm. 581 MethodType lambdaType = srcType.invokerType(); 582 Name[] names = arguments(spreadArgCount + 2, lambdaType); 583 int nameCursor = lambdaType.parameterCount(); 584 int[] indexes = new int[targetType.parameterCount()]; 585 586 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) { 587 Class<?> src = lambdaType.parameterType(i); 588 if (i == spreadArgPos) { 589 // Spread the array. 590 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType); 591 Name array = names[argIndex]; 592 names[nameCursor++] = new Name(NF_checkSpreadArgument, array, spreadArgCount); 593 for (int j = 0; j < spreadArgCount; i++, j++) { 594 indexes[i] = nameCursor; 595 names[nameCursor++] = new Name(aload, array, j); 596 } 597 } else if (i < indexes.length) { 598 indexes[i] = argIndex; 599 } 600 } 601 assert(nameCursor == names.length-1); // leave room for the final call 602 603 // Build argument array for the call. 604 Name[] targetArgs = new Name[targetType.parameterCount()]; 605 for (int i = 0; i < targetType.parameterCount(); i++) { 606 int idx = indexes[i]; 607 targetArgs[i] = names[idx]; 608 } 609 names[names.length - 1] = new Name(target, (Object[]) targetArgs); 610 611 LambdaForm form = new LambdaForm("spread", lambdaType.parameterCount(), names); 612 return SimpleMethodHandle.make(srcType, form); 613 } 614 615 static void checkSpreadArgument(Object av, int n) { 616 if (av == null) { 617 if (n == 0) return; 618 } else if (av instanceof Object[]) { 619 int len = ((Object[])av).length; 620 if (len == n) return; 621 } else { 622 int len = java.lang.reflect.Array.getLength(av); 623 if (len == n) return; 624 } 625 // fall through to error: 626 throw newIllegalArgumentException("array is not of length "+n); 627 } 628 629 /** Factory method: Collect or filter selected argument(s). */ 630 static MethodHandle makeCollectArguments(MethodHandle target, 631 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) { 632 MethodType targetType = target.type(); // (a..., c, [b...])=>r 633 MethodType collectorType = collector.type(); // (b...)=>c 634 int collectArgCount = collectorType.parameterCount(); 635 Class<?> collectValType = collectorType.returnType(); 636 int collectValCount = (collectValType == void.class ? 0 : 1); 637 MethodType srcType = targetType // (a..., [b...])=>r 638 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount); 639 if (!retainOriginalArgs) { // (a..., b...)=>r 640 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterArray()); 641 } 642 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ] 643 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ] 644 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ] 645 646 // Now build a LambdaForm. 647 MethodType lambdaType = srcType.invokerType(); 648 Name[] names = arguments(2, lambdaType); 649 final int collectNamePos = names.length - 2; 650 final int targetNamePos = names.length - 1; 651 652 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount); 653 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs); 654 655 // Build argument array for the target. 656 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ]. 657 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ]. 658 Name[] targetArgs = new Name[targetType.parameterCount()]; 659 int inputArgPos = 1; // incoming LF args to copy to target 660 int targetArgPos = 0; // fill pointer for targetArgs 661 int chunk = collectArgPos; // |headArgs| 662 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 663 inputArgPos += chunk; 664 targetArgPos += chunk; 665 if (collectValType != void.class) { 666 targetArgs[targetArgPos++] = names[collectNamePos]; 667 } 668 chunk = collectArgCount; 669 if (retainOriginalArgs) { 670 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 671 targetArgPos += chunk; // optionally pass on the collected chunk 672 } 673 inputArgPos += chunk; 674 chunk = targetArgs.length - targetArgPos; // all the rest 675 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk); 676 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also 677 names[targetNamePos] = new Name(target, (Object[]) targetArgs); 678 679 LambdaForm form = new LambdaForm("collect", lambdaType.parameterCount(), names); 680 return SimpleMethodHandle.make(srcType, form); 681 } 682 683 @LambdaForm.Hidden 684 static 685 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) { 686 if (testResult) { 687 return target; 688 } else { 689 return fallback; 690 } 691 } 692 693 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies. 694 @LambdaForm.Hidden 695 @jdk.internal.HotSpotIntrinsicCandidate 696 static 697 boolean profileBoolean(boolean result, int[] counters) { 698 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively. 699 int idx = result ? 1 : 0; 700 try { 701 counters[idx] = Math.addExact(counters[idx], 1); 702 } catch (ArithmeticException e) { 703 // Avoid continuous overflow by halving the problematic count. 704 counters[idx] = counters[idx] / 2; 705 } 706 return result; 707 } 708 709 // Intrinsified by C2. Returns true if obj is a compile-time constant. 710 @LambdaForm.Hidden 711 @jdk.internal.HotSpotIntrinsicCandidate 712 static 713 boolean isCompileConstant(Object obj) { 714 return false; 715 } 716 717 static 718 MethodHandle makeGuardWithTest(MethodHandle test, 719 MethodHandle target, 720 MethodHandle fallback) { 721 MethodType type = target.type(); 722 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type)); 723 MethodType basicType = type.basicType(); 724 LambdaForm form = makeGuardWithTestForm(basicType); 725 BoundMethodHandle mh; 726 try { 727 if (PROFILE_GWT) { 728 int[] counts = new int[2]; 729 mh = (BoundMethodHandle) 730 BoundMethodHandle.speciesData_LLLL().constructor().invokeBasic(type, form, 731 (Object) test, (Object) profile(target), (Object) profile(fallback), counts); 732 } else { 733 mh = (BoundMethodHandle) 734 BoundMethodHandle.speciesData_LLL().constructor().invokeBasic(type, form, 735 (Object) test, (Object) profile(target), (Object) profile(fallback)); 736 } 737 } catch (Throwable ex) { 738 throw uncaughtException(ex); 739 } 740 assert(mh.type() == type); 741 return mh; 742 } 743 744 745 static 746 MethodHandle profile(MethodHandle target) { 747 if (DONT_INLINE_THRESHOLD >= 0) { 748 return makeBlockInliningWrapper(target); 749 } else { 750 return target; 751 } 752 } 753 754 /** 755 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times. 756 * Corresponding LambdaForm has @DontInline when compiled into bytecode. 757 */ 758 static 759 MethodHandle makeBlockInliningWrapper(MethodHandle target) { 760 LambdaForm lform; 761 if (DONT_INLINE_THRESHOLD > 0) { 762 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target); 763 } else { 764 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target); 765 } 766 return new CountingWrapper(target, lform, 767 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM, 768 DONT_INLINE_THRESHOLD); 769 } 770 771 private final static class Makers { 772 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */ 773 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() { 774 @Override 775 public LambdaForm apply(MethodHandle target) { 776 return DelegatingMethodHandle.makeReinvokerForm(target, 777 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, "reinvoker.dontInline", false, 778 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting); 779 } 780 }; 781 782 /** Constructs simple reinvoker lambda form for a particular method handle */ 783 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() { 784 @Override 785 public LambdaForm apply(MethodHandle target) { 786 return DelegatingMethodHandle.makeReinvokerForm(target, 787 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget); 788 } 789 }; 790 791 /** Maker of type-polymorphic varargs */ 792 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() { 793 @Override 794 protected MethodHandle[] computeValue(Class<?> type) { 795 return new MethodHandle[MAX_JVM_ARITY + 1]; 796 } 797 }; 798 } 799 800 /** 801 * Counting method handle. It has 2 states: counting and non-counting. 802 * It is in counting state for the first n invocations and then transitions to non-counting state. 803 * Behavior in counting and non-counting states is determined by lambda forms produced by 804 * countingFormProducer & nonCountingFormProducer respectively. 805 */ 806 static class CountingWrapper extends DelegatingMethodHandle { 807 private final MethodHandle target; 808 private int count; 809 private Function<MethodHandle, LambdaForm> countingFormProducer; 810 private Function<MethodHandle, LambdaForm> nonCountingFormProducer; 811 private volatile boolean isCounting; 812 813 private CountingWrapper(MethodHandle target, LambdaForm lform, 814 Function<MethodHandle, LambdaForm> countingFromProducer, 815 Function<MethodHandle, LambdaForm> nonCountingFormProducer, 816 int count) { 817 super(target.type(), lform); 818 this.target = target; 819 this.count = count; 820 this.countingFormProducer = countingFromProducer; 821 this.nonCountingFormProducer = nonCountingFormProducer; 822 this.isCounting = (count > 0); 823 } 824 825 @Hidden 826 @Override 827 protected MethodHandle getTarget() { 828 return target; 829 } 830 831 @Override 832 public MethodHandle asTypeUncached(MethodType newType) { 833 MethodHandle newTarget = target.asType(newType); 834 MethodHandle wrapper; 835 if (isCounting) { 836 LambdaForm lform; 837 lform = countingFormProducer.apply(newTarget); 838 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD); 839 } else { 840 wrapper = newTarget; // no need for a counting wrapper anymore 841 } 842 return (asTypeCache = wrapper); 843 } 844 845 // Customize target if counting happens for too long. 846 private int invocations = CUSTOMIZE_THRESHOLD; 847 private void maybeCustomizeTarget() { 848 int c = invocations; 849 if (c >= 0) { 850 if (c == 1) { 851 target.customize(); 852 } 853 invocations = c - 1; 854 } 855 } 856 857 boolean countDown() { 858 int c = count; 859 maybeCustomizeTarget(); 860 if (c <= 1) { 861 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility. 862 if (isCounting) { 863 isCounting = false; 864 return true; 865 } else { 866 return false; 867 } 868 } else { 869 count = c - 1; 870 return false; 871 } 872 } 873 874 @Hidden 875 static void maybeStopCounting(Object o1) { 876 CountingWrapper wrapper = (CountingWrapper) o1; 877 if (wrapper.countDown()) { 878 // Reached invocation threshold. Replace counting behavior with a non-counting one. 879 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target); 880 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition 881 wrapper.updateForm(lform); 882 } 883 } 884 885 static final NamedFunction NF_maybeStopCounting; 886 static { 887 Class<?> THIS_CLASS = CountingWrapper.class; 888 try { 889 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class)); 890 } catch (ReflectiveOperationException ex) { 891 throw newInternalError(ex); 892 } 893 } 894 } 895 896 static 897 LambdaForm makeGuardWithTestForm(MethodType basicType) { 898 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT); 899 if (lform != null) return lform; 900 final int THIS_MH = 0; // the BMH_LLL 901 final int ARG_BASE = 1; // start of incoming arguments 902 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 903 int nameCursor = ARG_LIMIT; 904 final int GET_TEST = nameCursor++; 905 final int GET_TARGET = nameCursor++; 906 final int GET_FALLBACK = nameCursor++; 907 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1; 908 final int CALL_TEST = nameCursor++; 909 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1; 910 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST 911 final int SELECT_ALT = nameCursor++; 912 final int CALL_TARGET = nameCursor++; 913 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative 914 915 MethodType lambdaType = basicType.invokerType(); 916 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 917 918 BoundMethodHandle.SpeciesData data = 919 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL() 920 : BoundMethodHandle.speciesData_LLL(); 921 names[THIS_MH] = names[THIS_MH].withConstraint(data); 922 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]); 923 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]); 924 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]); 925 if (GET_COUNTERS != -1) { 926 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]); 927 } 928 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class); 929 930 // call test 931 MethodType testType = basicType.changeReturnType(boolean.class).basicType(); 932 invokeArgs[0] = names[GET_TEST]; 933 names[CALL_TEST] = new Name(testType, invokeArgs); 934 935 // profile branch 936 if (PROFILE != -1) { 937 names[PROFILE] = new Name(NF_profileBoolean, names[CALL_TEST], names[GET_COUNTERS]); 938 } 939 // call selectAlternative 940 names[SELECT_ALT] = new Name(getConstantHandle(MH_selectAlternative), names[TEST], names[GET_TARGET], names[GET_FALLBACK]); 941 942 // call target or fallback 943 invokeArgs[0] = names[SELECT_ALT]; 944 names[CALL_TARGET] = new Name(basicType, invokeArgs); 945 946 lform = new LambdaForm("guard", lambdaType.parameterCount(), names, /*forceInline=*/true); 947 948 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform); 949 } 950 951 /** 952 * The LambdaForm shape for catchException combinator is the following: 953 * <blockquote><pre>{@code 954 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{ 955 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L); 956 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L); 957 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L); 958 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L); 959 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L); 960 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L); 961 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L); 962 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I} 963 * }</pre></blockquote> 964 * 965 * argL0 and argL2 are target and catcher method handles. argL1 is exception class. 966 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[] 967 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()). 968 * 969 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms 970 * among catchException combinators with the same basic type. 971 */ 972 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) { 973 MethodType lambdaType = basicType.invokerType(); 974 975 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC); 976 if (lform != null) { 977 return lform; 978 } 979 final int THIS_MH = 0; // the BMH_LLLLL 980 final int ARG_BASE = 1; // start of incoming arguments 981 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 982 983 int nameCursor = ARG_LIMIT; 984 final int GET_TARGET = nameCursor++; 985 final int GET_CLASS = nameCursor++; 986 final int GET_CATCHER = nameCursor++; 987 final int GET_COLLECT_ARGS = nameCursor++; 988 final int GET_UNBOX_RESULT = nameCursor++; 989 final int BOXED_ARGS = nameCursor++; 990 final int TRY_CATCH = nameCursor++; 991 final int UNBOX_RESULT = nameCursor++; 992 993 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 994 995 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL(); 996 names[THIS_MH] = names[THIS_MH].withConstraint(data); 997 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]); 998 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]); 999 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]); 1000 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]); 1001 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]); 1002 1003 // FIXME: rework argument boxing/result unboxing logic for LF interpretation 1004 1005 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 1006 MethodType collectArgsType = basicType.changeReturnType(Object.class); 1007 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 1008 Object[] args = new Object[invokeBasic.type().parameterCount()]; 1009 args[0] = names[GET_COLLECT_ARGS]; 1010 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE); 1011 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args); 1012 1013 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L); 1014 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]}; 1015 names[TRY_CATCH] = new Name(NF_guardWithCatch, gwcArgs); 1016 1017 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 1018 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 1019 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]}; 1020 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 1021 1022 lform = new LambdaForm("guardWithCatch", lambdaType.parameterCount(), names); 1023 1024 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform); 1025 } 1026 1027 static 1028 MethodHandle makeGuardWithCatch(MethodHandle target, 1029 Class<? extends Throwable> exType, 1030 MethodHandle catcher) { 1031 MethodType type = target.type(); 1032 LambdaForm form = makeGuardWithCatchForm(type.basicType()); 1033 1034 // Prepare auxiliary method handles used during LambdaForm interpretation. 1035 // Box arguments and wrap them into Object[]: ValueConversions.array(). 1036 MethodType varargsType = type.changeReturnType(Object[].class); 1037 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 1038 MethodHandle unboxResult = unboxResultHandle(type.returnType()); 1039 1040 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL(); 1041 BoundMethodHandle mh; 1042 try { 1043 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) exType, 1044 (Object) catcher, (Object) collectArgs, (Object) unboxResult); 1045 } catch (Throwable ex) { 1046 throw uncaughtException(ex); 1047 } 1048 assert(mh.type() == type); 1049 return mh; 1050 } 1051 1052 /** 1053 * Intrinsified during LambdaForm compilation 1054 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}). 1055 */ 1056 @LambdaForm.Hidden 1057 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher, 1058 Object... av) throws Throwable { 1059 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case. 1060 try { 1061 return target.asFixedArity().invokeWithArguments(av); 1062 } catch (Throwable t) { 1063 if (!exType.isInstance(t)) throw t; 1064 return catcher.asFixedArity().invokeWithArguments(prepend(av, t)); 1065 } 1066 } 1067 1068 /** Prepend elements to an array. */ 1069 @LambdaForm.Hidden 1070 private static Object[] prepend(Object[] array, Object... elems) { 1071 int nArray = array.length; 1072 int nElems = elems.length; 1073 Object[] newArray = new Object[nArray + nElems]; 1074 System.arraycopy(elems, 0, newArray, 0, nElems); 1075 System.arraycopy(array, 0, newArray, nElems, nArray); 1076 return newArray; 1077 } 1078 1079 static 1080 MethodHandle throwException(MethodType type) { 1081 assert(Throwable.class.isAssignableFrom(type.parameterType(0))); 1082 int arity = type.parameterCount(); 1083 if (arity > 1) { 1084 MethodHandle mh = throwException(type.dropParameterTypes(1, arity)); 1085 mh = MethodHandles.dropArguments(mh, 1, Arrays.copyOfRange(type.parameterArray(), 1, arity)); 1086 return mh; 1087 } 1088 return makePairwiseConvert(NF_throwException.resolvedHandle(), type, false, true); 1089 } 1090 1091 static <T extends Throwable> Empty throwException(T t) throws T { throw t; } 1092 1093 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2]; 1094 static MethodHandle fakeMethodHandleInvoke(MemberName method) { 1095 int idx; 1096 assert(method.isMethodHandleInvoke()); 1097 switch (method.getName()) { 1098 case "invoke": idx = 0; break; 1099 case "invokeExact": idx = 1; break; 1100 default: throw new InternalError(method.getName()); 1101 } 1102 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx]; 1103 if (mh != null) return mh; 1104 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class, 1105 MethodHandle.class, Object[].class); 1106 mh = throwException(type); 1107 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle")); 1108 if (!method.getInvocationType().equals(mh.type())) 1109 throw new InternalError(method.toString()); 1110 mh = mh.withInternalMemberName(method, false); 1111 mh = mh.withVarargs(true); 1112 assert(method.isVarargs()); 1113 FAKE_METHOD_HANDLE_INVOKE[idx] = mh; 1114 return mh; 1115 } 1116 static MethodHandle fakeVarHandleInvoke(MemberName method) { 1117 // TODO caching, is it necessary? 1118 MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class, 1119 VarHandle.class, Object[].class); 1120 MethodHandle mh = throwException(type); 1121 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle")); 1122 if (!method.getInvocationType().equals(mh.type())) 1123 throw new InternalError(method.toString()); 1124 mh = mh.withInternalMemberName(method, false); 1125 mh = mh.asVarargsCollector(Object[].class); 1126 assert(method.isVarargs()); 1127 return mh; 1128 } 1129 1130 /** 1131 * Create an alias for the method handle which, when called, 1132 * appears to be called from the same class loader and protection domain 1133 * as hostClass. 1134 * This is an expensive no-op unless the method which is called 1135 * is sensitive to its caller. A small number of system methods 1136 * are in this category, including Class.forName and Method.invoke. 1137 */ 1138 static 1139 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) { 1140 return BindCaller.bindCaller(mh, hostClass); 1141 } 1142 1143 // Put the whole mess into its own nested class. 1144 // That way we can lazily load the code and set up the constants. 1145 private static class BindCaller { 1146 private static MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class); 1147 1148 static 1149 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) { 1150 // Do not use this function to inject calls into system classes. 1151 if (hostClass == null 1152 || (hostClass.isArray() || 1153 hostClass.isPrimitive() || 1154 hostClass.getName().startsWith("java.") || 1155 hostClass.getName().startsWith("sun."))) { 1156 throw new InternalError(); // does not happen, and should not anyway 1157 } 1158 // For simplicity, convert mh to a varargs-like method. 1159 MethodHandle vamh = prepareForInvoker(mh); 1160 // Cache the result of makeInjectedInvoker once per argument class. 1161 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass); 1162 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass); 1163 } 1164 1165 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) { 1166 try { 1167 Class<?> invokerClass = UNSAFE.defineAnonymousClass(hostClass, INJECTED_INVOKER_TEMPLATE, null); 1168 assert checkInjectedInvoker(hostClass, invokerClass); 1169 return IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT); 1170 } catch (ReflectiveOperationException ex) { 1171 throw uncaughtException(ex); 1172 } 1173 } 1174 1175 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() { 1176 @Override protected MethodHandle computeValue(Class<?> hostClass) { 1177 return makeInjectedInvoker(hostClass); 1178 } 1179 }; 1180 1181 // Adapt mh so that it can be called directly from an injected invoker: 1182 private static MethodHandle prepareForInvoker(MethodHandle mh) { 1183 mh = mh.asFixedArity(); 1184 MethodType mt = mh.type(); 1185 int arity = mt.parameterCount(); 1186 MethodHandle vamh = mh.asType(mt.generic()); 1187 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames 1188 vamh = vamh.asSpreader(Object[].class, arity); 1189 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames 1190 return vamh; 1191 } 1192 1193 // Undo the adapter effect of prepareForInvoker: 1194 private static MethodHandle restoreToType(MethodHandle vamh, 1195 MethodHandle original, 1196 Class<?> hostClass) { 1197 MethodType type = original.type(); 1198 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount()); 1199 MemberName member = original.internalMemberName(); 1200 mh = mh.asType(type); 1201 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass); 1202 return mh; 1203 } 1204 1205 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) { 1206 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)"; 1207 try { 1208 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)"; 1209 } catch (SecurityException ex) { 1210 // Self-check was blocked by security manager. This is OK. 1211 } 1212 try { 1213 // Test the invoker to ensure that it really injects into the right place. 1214 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT); 1215 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass); 1216 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass }); 1217 } catch (Throwable ex) { 1218 throw new InternalError(ex); 1219 } 1220 } 1221 1222 private static final MethodHandle MH_checkCallerClass; 1223 static { 1224 final Class<?> THIS_CLASS = BindCaller.class; 1225 assert(checkCallerClass(THIS_CLASS)); 1226 try { 1227 MH_checkCallerClass = IMPL_LOOKUP 1228 .findStatic(THIS_CLASS, "checkCallerClass", 1229 MethodType.methodType(boolean.class, Class.class)); 1230 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS)); 1231 } catch (Throwable ex) { 1232 throw new InternalError(ex); 1233 } 1234 } 1235 1236 @CallerSensitive 1237 @ForceInline // to ensure Reflection.getCallerClass optimization 1238 private static boolean checkCallerClass(Class<?> expected) { 1239 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here. 1240 Class<?> actual = Reflection.getCallerClass(); 1241 if (actual != expected) 1242 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName()); 1243 return true; 1244 } 1245 1246 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate(); 1247 1248 /** Produces byte code for a class that is used as an injected invoker. */ 1249 private static byte[] generateInvokerTemplate() { 1250 ClassWriter cw = new ClassWriter(0); 1251 1252 // private static class InjectedInvoker { 1253 // @Hidden 1254 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable { 1255 // return vamh.invokeExact(args); 1256 // } 1257 // } 1258 cw.visit(52, ACC_PRIVATE | ACC_SUPER, "InjectedInvoker", null, "java/lang/Object", null); 1259 1260 MethodVisitor mv = cw.visitMethod(ACC_STATIC, "invoke_V", 1261 "(Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;", 1262 null, null); 1263 1264 // Suppress invoker method in stack traces. 1265 AnnotationVisitor av0 = mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true); 1266 av0.visitEnd(); 1267 1268 mv.visitCode(); 1269 mv.visitVarInsn(ALOAD, 0); 1270 mv.visitVarInsn(ALOAD, 1); 1271 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle", "invokeExact", 1272 "([Ljava/lang/Object;)Ljava/lang/Object;", false); 1273 mv.visitInsn(ARETURN); 1274 mv.visitMaxs(2, 2); 1275 mv.visitEnd(); 1276 1277 cw.visitEnd(); 1278 return cw.toByteArray(); 1279 } 1280 } 1281 1282 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */ 1283 private static final class WrappedMember extends DelegatingMethodHandle { 1284 private final MethodHandle target; 1285 private final MemberName member; 1286 private final Class<?> callerClass; 1287 private final boolean isInvokeSpecial; 1288 1289 private WrappedMember(MethodHandle target, MethodType type, 1290 MemberName member, boolean isInvokeSpecial, 1291 Class<?> callerClass) { 1292 super(type, target); 1293 this.target = target; 1294 this.member = member; 1295 this.callerClass = callerClass; 1296 this.isInvokeSpecial = isInvokeSpecial; 1297 } 1298 1299 @Override 1300 MemberName internalMemberName() { 1301 return member; 1302 } 1303 @Override 1304 Class<?> internalCallerClass() { 1305 return callerClass; 1306 } 1307 @Override 1308 boolean isInvokeSpecial() { 1309 return isInvokeSpecial; 1310 } 1311 @Override 1312 protected MethodHandle getTarget() { 1313 return target; 1314 } 1315 @Override 1316 public MethodHandle asTypeUncached(MethodType newType) { 1317 // This MH is an alias for target, except for the MemberName 1318 // Drop the MemberName if there is any conversion. 1319 return asTypeCache = target.asType(newType); 1320 } 1321 } 1322 1323 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) { 1324 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial()) 1325 return target; 1326 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null); 1327 } 1328 1329 /** Intrinsic IDs */ 1330 /*non-public*/ 1331 enum Intrinsic { 1332 SELECT_ALTERNATIVE, 1333 GUARD_WITH_CATCH, 1334 TRY_FINALLY, 1335 LOOP, 1336 NEW_ARRAY, 1337 ARRAY_LOAD, 1338 ARRAY_STORE, 1339 ARRAY_LENGTH, 1340 IDENTITY, 1341 ZERO, 1342 NONE // no intrinsic associated 1343 } 1344 1345 /** Mark arbitrary method handle as intrinsic. 1346 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */ 1347 static final class IntrinsicMethodHandle extends DelegatingMethodHandle { 1348 private final MethodHandle target; 1349 private final Intrinsic intrinsicName; 1350 1351 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) { 1352 super(target.type(), target); 1353 this.target = target; 1354 this.intrinsicName = intrinsicName; 1355 } 1356 1357 @Override 1358 protected MethodHandle getTarget() { 1359 return target; 1360 } 1361 1362 @Override 1363 Intrinsic intrinsicName() { 1364 return intrinsicName; 1365 } 1366 1367 @Override 1368 public MethodHandle asTypeUncached(MethodType newType) { 1369 // This MH is an alias for target, except for the intrinsic name 1370 // Drop the name if there is any conversion. 1371 return asTypeCache = target.asType(newType); 1372 } 1373 1374 @Override 1375 String internalProperties() { 1376 return super.internalProperties() + 1377 "\n& Intrinsic="+intrinsicName; 1378 } 1379 1380 @Override 1381 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) { 1382 if (intrinsicName == Intrinsic.IDENTITY) { 1383 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength); 1384 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength); 1385 return newArray.asType(resultType); 1386 } 1387 return super.asCollector(arrayType, arrayLength); 1388 } 1389 } 1390 1391 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) { 1392 if (intrinsicName == target.intrinsicName()) 1393 return target; 1394 return new IntrinsicMethodHandle(target, intrinsicName); 1395 } 1396 1397 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) { 1398 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName); 1399 } 1400 1401 /// Collection of multiple arguments. 1402 1403 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) { 1404 MethodType type = MethodType.genericMethodType(nargs) 1405 .changeReturnType(rtype) 1406 .insertParameterTypes(0, ptypes); 1407 try { 1408 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type); 1409 } catch (ReflectiveOperationException ex) { 1410 return null; 1411 } 1412 } 1413 1414 private static final Object[] NO_ARGS_ARRAY = {}; 1415 private static Object[] makeArray(Object... args) { return args; } 1416 private static Object[] array() { return NO_ARGS_ARRAY; } 1417 private static Object[] array(Object a0) 1418 { return makeArray(a0); } 1419 private static Object[] array(Object a0, Object a1) 1420 { return makeArray(a0, a1); } 1421 private static Object[] array(Object a0, Object a1, Object a2) 1422 { return makeArray(a0, a1, a2); } 1423 private static Object[] array(Object a0, Object a1, Object a2, Object a3) 1424 { return makeArray(a0, a1, a2, a3); } 1425 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1426 Object a4) 1427 { return makeArray(a0, a1, a2, a3, a4); } 1428 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1429 Object a4, Object a5) 1430 { return makeArray(a0, a1, a2, a3, a4, a5); } 1431 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1432 Object a4, Object a5, Object a6) 1433 { return makeArray(a0, a1, a2, a3, a4, a5, a6); } 1434 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1435 Object a4, Object a5, Object a6, Object a7) 1436 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); } 1437 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1438 Object a4, Object a5, Object a6, Object a7, 1439 Object a8) 1440 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); } 1441 private static Object[] array(Object a0, Object a1, Object a2, Object a3, 1442 Object a4, Object a5, Object a6, Object a7, 1443 Object a8, Object a9) 1444 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); } 1445 1446 private static final int ARRAYS_COUNT = 11; 1447 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1]; 1448 1449 // filling versions of the above: 1450 // using Integer len instead of int len and no varargs to avoid bootstrapping problems 1451 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) { 1452 Object[] a = new Object[len]; 1453 fillWithArguments(a, 0, args); 1454 return a; 1455 } 1456 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) { 1457 Object[] a = Arrays.copyOf(example, len); 1458 assert(a.getClass() != Object[].class); 1459 fillWithArguments(a, 0, args); 1460 return a; 1461 } 1462 private static void fillWithArguments(Object[] a, int pos, Object... args) { 1463 System.arraycopy(args, 0, a, pos, args.length); 1464 } 1465 // using Integer pos instead of int pos to avoid bootstrapping problems 1466 private static Object[] fillArray(Integer pos, Object[] a, Object a0) 1467 { fillWithArguments(a, pos, a0); return a; } 1468 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1) 1469 { fillWithArguments(a, pos, a0, a1); return a; } 1470 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2) 1471 { fillWithArguments(a, pos, a0, a1, a2); return a; } 1472 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3) 1473 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; } 1474 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1475 Object a4) 1476 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; } 1477 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1478 Object a4, Object a5) 1479 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; } 1480 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1481 Object a4, Object a5, Object a6) 1482 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; } 1483 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1484 Object a4, Object a5, Object a6, Object a7) 1485 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; } 1486 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1487 Object a4, Object a5, Object a6, Object a7, 1488 Object a8) 1489 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; } 1490 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3, 1491 Object a4, Object a5, Object a6, Object a7, 1492 Object a8, Object a9) 1493 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; } 1494 1495 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods 1496 private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT]; 1497 1498 private static MethodHandle getFillArray(int count) { 1499 assert (count > 0 && count < FILL_ARRAYS_COUNT); 1500 MethodHandle mh = FILL_ARRAYS[count]; 1501 if (mh != null) { 1502 return mh; 1503 } 1504 mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class); 1505 FILL_ARRAYS[count] = mh; 1506 return mh; 1507 } 1508 1509 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) { 1510 Object a = w.makeArray(boxes.length); 1511 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length); 1512 return a; 1513 } 1514 1515 /** Return a method handle that takes the indicated number of Object 1516 * arguments and returns an Object array of them, as if for varargs. 1517 */ 1518 static MethodHandle varargsArray(int nargs) { 1519 MethodHandle mh = ARRAYS[nargs]; 1520 if (mh != null) { 1521 return mh; 1522 } 1523 if (nargs < ARRAYS_COUNT) { 1524 mh = findCollector("array", nargs, Object[].class); 1525 } else { 1526 mh = buildVarargsArray(getConstantHandle(MH_fillNewArray), 1527 getConstantHandle(MH_arrayIdentity), nargs); 1528 } 1529 assert(assertCorrectArity(mh, nargs)); 1530 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY); 1531 return ARRAYS[nargs] = mh; 1532 } 1533 1534 private static boolean assertCorrectArity(MethodHandle mh, int arity) { 1535 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh; 1536 return true; 1537 } 1538 1539 // Array identity function (used as getConstantHandle(MH_arrayIdentity)). 1540 static <T> T[] identity(T[] x) { 1541 return x; 1542 } 1543 1544 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) { 1545 // Build up the result mh as a sequence of fills like this: 1546 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23)) 1547 // The various fill(_,10*I,___*[J]) are reusable. 1548 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately 1549 int rightLen = nargs - leftLen; 1550 MethodHandle leftCollector = newArray.bindTo(nargs); 1551 leftCollector = leftCollector.asCollector(Object[].class, leftLen); 1552 MethodHandle mh = finisher; 1553 if (rightLen > 0) { 1554 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen); 1555 if (mh.equals(getConstantHandle(MH_arrayIdentity))) 1556 mh = rightFiller; 1557 else 1558 mh = MethodHandles.collectArguments(mh, 0, rightFiller); 1559 } 1560 if (mh.equals(getConstantHandle(MH_arrayIdentity))) 1561 mh = leftCollector; 1562 else 1563 mh = MethodHandles.collectArguments(mh, 0, leftCollector); 1564 return mh; 1565 } 1566 1567 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1; 1568 private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1]; 1569 /** fill_array_to_right(N).invoke(a, argL..arg[N-1]) 1570 * fills a[L]..a[N-1] with corresponding arguments, 1571 * and then returns a. The value L is a global constant (LEFT_ARGS). 1572 */ 1573 private static MethodHandle fillToRight(int nargs) { 1574 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs]; 1575 if (filler != null) return filler; 1576 filler = buildFiller(nargs); 1577 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1)); 1578 return FILL_ARRAY_TO_RIGHT[nargs] = filler; 1579 } 1580 private static MethodHandle buildFiller(int nargs) { 1581 if (nargs <= LEFT_ARGS) 1582 return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged 1583 // we need room for both mh and a in mh.invoke(a, arg*[nargs]) 1584 final int CHUNK = LEFT_ARGS; 1585 int rightLen = nargs % CHUNK; 1586 int midLen = nargs - rightLen; 1587 if (rightLen == 0) { 1588 midLen = nargs - (rightLen = CHUNK); 1589 if (FILL_ARRAY_TO_RIGHT[midLen] == null) { 1590 // build some precursors from left to right 1591 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK) 1592 if (j > LEFT_ARGS) fillToRight(j); 1593 } 1594 } 1595 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS); 1596 assert(rightLen > 0); 1597 MethodHandle midFill = fillToRight(midLen); // recursive fill 1598 MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1] 1599 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS); 1600 assert(rightFill.type().parameterCount() == 1 + rightLen); 1601 1602 // Combine the two fills: 1603 // right(mid(a, x10..x19), x20..x23) 1604 // The final product will look like this: 1605 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23) 1606 if (midLen == LEFT_ARGS) 1607 return rightFill; 1608 else 1609 return MethodHandles.collectArguments(rightFill, 0, midFill); 1610 } 1611 1612 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM 1613 1614 /** Return a method handle that takes the indicated number of 1615 * typed arguments and returns an array of them. 1616 * The type argument is the array type. 1617 */ 1618 static MethodHandle varargsArray(Class<?> arrayType, int nargs) { 1619 Class<?> elemType = arrayType.getComponentType(); 1620 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType); 1621 // FIXME: Need more special casing and caching here. 1622 if (nargs >= MAX_JVM_ARITY/2 - 1) { 1623 int slots = nargs; 1624 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH 1625 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive()) 1626 slots *= Wrapper.forPrimitiveType(elemType).stackSlots(); 1627 if (slots > MAX_ARRAY_SLOTS) 1628 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs); 1629 } 1630 if (elemType == Object.class) 1631 return varargsArray(nargs); 1632 // other cases: primitive arrays, subtypes of Object[] 1633 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType); 1634 MethodHandle mh = nargs < cache.length ? cache[nargs] : null; 1635 if (mh != null) return mh; 1636 if (nargs == 0) { 1637 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0); 1638 mh = MethodHandles.constant(arrayType, example); 1639 } else if (elemType.isPrimitive()) { 1640 MethodHandle builder = getConstantHandle(MH_fillNewArray); 1641 MethodHandle producer = buildArrayProducer(arrayType); 1642 mh = buildVarargsArray(builder, producer, nargs); 1643 } else { 1644 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class); 1645 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType); 1646 MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example); 1647 MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed 1648 mh = buildVarargsArray(builder, producer, nargs); 1649 } 1650 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType))); 1651 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY); 1652 assert(assertCorrectArity(mh, nargs)); 1653 if (nargs < cache.length) 1654 cache[nargs] = mh; 1655 return mh; 1656 } 1657 1658 private static MethodHandle buildArrayProducer(Class<?> arrayType) { 1659 Class<?> elemType = arrayType.getComponentType(); 1660 assert(elemType.isPrimitive()); 1661 return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType)); 1662 } 1663 1664 /*non-public*/ static void assertSame(Object mh1, Object mh2) { 1665 if (mh1 != mh2) { 1666 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)", 1667 mh1, ((MethodHandle)mh1).form, 1668 mh2, ((MethodHandle)mh2).form); 1669 throw newInternalError(msg); 1670 } 1671 } 1672 1673 // Local constant functions: 1674 /*non-public*/ static final NamedFunction 1675 NF_checkSpreadArgument, 1676 NF_guardWithCatch, 1677 NF_throwException, 1678 NF_tryFinally, 1679 NF_loop, 1680 NF_profileBoolean; 1681 1682 static { 1683 try { 1684 NF_checkSpreadArgument = new NamedFunction(MethodHandleImpl.class 1685 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class)); 1686 NF_guardWithCatch = new NamedFunction(MethodHandleImpl.class 1687 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class, 1688 MethodHandle.class, Object[].class)); 1689 NF_tryFinally = new NamedFunction(MethodHandleImpl.class 1690 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class)); 1691 NF_loop = new NamedFunction(MethodHandleImpl.class 1692 .getDeclaredMethod("loop", BasicType[].class, MethodHandle[].class, MethodHandle[].class, 1693 MethodHandle[].class, MethodHandle[].class, Object[].class)); 1694 NF_throwException = new NamedFunction(MethodHandleImpl.class 1695 .getDeclaredMethod("throwException", Throwable.class)); 1696 NF_profileBoolean = new NamedFunction(MethodHandleImpl.class 1697 .getDeclaredMethod("profileBoolean", boolean.class, int[].class)); 1698 } catch (ReflectiveOperationException ex) { 1699 throw newInternalError(ex); 1700 } 1701 1702 SharedSecrets.setJavaLangInvokeAccess(new JavaLangInvokeAccess() { 1703 @Override 1704 public Object newMemberName() { 1705 return new MemberName(); 1706 } 1707 1708 @Override 1709 public String getName(Object mname) { 1710 MemberName memberName = (MemberName)mname; 1711 return memberName.getName(); 1712 } 1713 1714 @Override 1715 public boolean isNative(Object mname) { 1716 MemberName memberName = (MemberName)mname; 1717 return memberName.isNative(); 1718 } 1719 1720 @Override 1721 public byte[] generateDMHClassBytes(String className, 1722 MethodType[] methodTypes, int[] types) { 1723 return GenerateJLIClassesHelper 1724 .generateDMHClassBytes(className, methodTypes, types); 1725 } 1726 1727 @Override 1728 public Map.Entry<String, byte[]> generateConcreteBMHClassBytes( 1729 final String types) { 1730 return GenerateJLIClassesHelper 1731 .generateConcreteBMHClassBytes(types); 1732 } 1733 }); 1734 } 1735 1736 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */ 1737 private static MethodHandle unboxResultHandle(Class<?> returnType) { 1738 if (returnType.isPrimitive()) { 1739 if (returnType == void.class) { 1740 return ValueConversions.ignore(); 1741 } else { 1742 Wrapper w = Wrapper.forPrimitiveType(returnType); 1743 return ValueConversions.unboxExact(w); 1744 } 1745 } else { 1746 return MethodHandles.identity(Object.class); 1747 } 1748 } 1749 1750 /** 1751 * Assembles a loop method handle from the given handles and type information. 1752 * 1753 * @param tloop the return type of the loop. 1754 * @param targs types of the arguments to be passed to the loop. 1755 * @param init sanitized array of initializers for loop-local variables. 1756 * @param step sanitited array of loop bodies. 1757 * @param pred sanitized array of predicates. 1758 * @param fini sanitized array of loop finalizers. 1759 * 1760 * @return a handle that, when invoked, will execute the loop. 1761 */ 1762 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step, 1763 List<MethodHandle> pred, List<MethodHandle> fini) { 1764 MethodType type = MethodType.methodType(tloop, targs); 1765 BasicType[] initClauseTypes = 1766 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new); 1767 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes); 1768 1769 // Prepare auxiliary method handles used during LambdaForm interpretation. 1770 // Box arguments and wrap them into Object[]: ValueConversions.array(). 1771 MethodType varargsType = type.changeReturnType(Object[].class); 1772 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 1773 MethodHandle unboxResult = unboxResultHandle(tloop); 1774 1775 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLLL(); 1776 BoundMethodHandle mh; 1777 try { 1778 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) toArray(init), 1779 (Object) toArray(step), (Object) toArray(pred), (Object) toArray(fini), (Object) collectArgs, 1780 (Object) unboxResult); 1781 } catch (Throwable ex) { 1782 throw uncaughtException(ex); 1783 } 1784 assert(mh.type() == type); 1785 return mh; 1786 } 1787 1788 private static MethodHandle[] toArray(List<MethodHandle> l) { 1789 return l.toArray(new MethodHandle[0]); 1790 } 1791 1792 /** 1793 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are 1794 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one 1795 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by 1796 * {@code t12}): 1797 * <blockquote><pre>{@code 1798 * loop=Lambda(a0:L,a1:L)=>{ 1799 * t2:L=BoundMethodHandle$Species_L6.argL0(a0:L); // array of init method handles 1800 * t3:L=BoundMethodHandle$Species_L6.argL1(a0:L); // array of step method handles 1801 * t4:L=BoundMethodHandle$Species_L6.argL2(a0:L); // array of pred method handles 1802 * t5:L=BoundMethodHandle$Species_L6.argL3(a0:L); // array of fini method handles 1803 * t6:L=BoundMethodHandle$Species_L6.argL4(a0:L); // helper handle to box the arguments into an Object[] 1804 * t7:L=BoundMethodHandle$Species_L6.argL5(a0:L); // helper handle to unbox the result 1805 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L); // box the arguments into an Object[] 1806 * t9:L=MethodHandleImpl.loop(null,t2:L,t3:L,t4:L,t5:L,t6:L); // call the loop executor 1807 * t10:L=MethodHandle.invokeBasic(t7:L,t9:L);t10:L} // unbox the result; return the result 1808 * }</pre></blockquote> 1809 * <p> 1810 * {@code argL0} through {@code argL3} are the arrays of init, step, pred, and fini method handles. 1811 * {@code argL4} and {@code argL5} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into 1812 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary 1813 * ({@code ValueConversions.unbox()}). 1814 * <p> 1815 * Having {@code t6} and {@code t7} passed in via a BMH and not hardcoded in the lambda form allows to share lambda 1816 * forms among loop combinators with the same basic type. 1817 * <p> 1818 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to 1819 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is 1820 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int) 1821 * bytecode generation}. 1822 */ 1823 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) { 1824 MethodType lambdaType = basicType.invokerType(); 1825 1826 final int THIS_MH = 0; // the BMH_LLLLLL 1827 final int ARG_BASE = 1; // start of incoming arguments 1828 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 1829 1830 int nameCursor = ARG_LIMIT; 1831 final int GET_INITS = nameCursor++; 1832 final int GET_STEPS = nameCursor++; 1833 final int GET_PREDS = nameCursor++; 1834 final int GET_FINIS = nameCursor++; 1835 final int GET_COLLECT_ARGS = nameCursor++; 1836 final int GET_UNBOX_RESULT = nameCursor++; 1837 final int BOXED_ARGS = nameCursor++; 1838 final int LOOP = nameCursor++; 1839 final int UNBOX_RESULT = nameCursor++; 1840 1841 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP); 1842 if (lform == null) { 1843 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 1844 1845 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLLL(); 1846 names[THIS_MH] = names[THIS_MH].withConstraint(data); 1847 names[GET_INITS] = new Name(data.getterFunction(0), names[THIS_MH]); 1848 names[GET_STEPS] = new Name(data.getterFunction(1), names[THIS_MH]); 1849 names[GET_PREDS] = new Name(data.getterFunction(2), names[THIS_MH]); 1850 names[GET_FINIS] = new Name(data.getterFunction(3), names[THIS_MH]); 1851 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(4), names[THIS_MH]); 1852 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(5), names[THIS_MH]); 1853 1854 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 1855 MethodType collectArgsType = basicType.changeReturnType(Object.class); 1856 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 1857 Object[] args = new Object[invokeBasic.type().parameterCount()]; 1858 args[0] = names[GET_COLLECT_ARGS]; 1859 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE); 1860 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.LOOP), args); 1861 1862 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,inits:L,steps:L,preds:L,finis:L,t_{i}:L); 1863 Object[] lArgs = 1864 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor 1865 names[GET_INITS], names[GET_STEPS], names[GET_PREDS], names[GET_FINIS], names[BOXED_ARGS]}; 1866 names[LOOP] = new Name(NF_loop, lArgs); 1867 1868 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 1869 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 1870 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]}; 1871 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 1872 1873 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP, 1874 new LambdaForm("loop", lambdaType.parameterCount(), names)); 1875 } 1876 1877 // BOXED_ARGS is the index into the names array where the loop idiom starts 1878 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes); 1879 } 1880 1881 1882 /** 1883 * Intrinsified during LambdaForm compilation 1884 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}). 1885 */ 1886 @LambdaForm.Hidden 1887 static Object loop(BasicType[] localTypes, MethodHandle[] init, MethodHandle[] step, MethodHandle[] pred, 1888 MethodHandle[] fini, Object... av) throws Throwable { 1889 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count(); 1890 int nArgs = init[0].type().parameterCount(); 1891 Object[] varsAndArgs = new Object[varSize + nArgs]; 1892 for (int i = 0, v = 0; i < init.length; ++i) { 1893 if (init[i].type().returnType() == void.class) { 1894 init[i].asFixedArity().invokeWithArguments(av); 1895 } else { 1896 varsAndArgs[v++] = init[i].asFixedArity().invokeWithArguments(av); 1897 } 1898 } 1899 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs); 1900 final int nSteps = step.length; 1901 for (; ; ) { 1902 for (int i = 0, v = 0; i < nSteps; ++i) { 1903 MethodHandle p = pred[i]; 1904 MethodHandle s = step[i]; 1905 MethodHandle f = fini[i]; 1906 if (s.type().returnType() == void.class) { 1907 s.asFixedArity().invokeWithArguments(varsAndArgs); 1908 } else { 1909 varsAndArgs[v++] = s.asFixedArity().invokeWithArguments(varsAndArgs); 1910 } 1911 if (!(boolean) p.asFixedArity().invokeWithArguments(varsAndArgs)) { 1912 return f.asFixedArity().invokeWithArguments(varsAndArgs); 1913 } 1914 } 1915 } 1916 } 1917 1918 /** 1919 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, 1920 * MethodHandle) counting loops}. 1921 * 1922 * @param counter the counter parameter, passed in during loop execution. 1923 * @param limit the upper bound of the parameter, statically bound at loop creation time. 1924 * 1925 * @return whether the counter has reached the limit. 1926 */ 1927 static boolean countedLoopPredicate(int counter, int limit) { 1928 return counter <= limit; 1929 } 1930 1931 /** 1932 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, 1933 * MethodHandle) counting loops} to increment the counter. 1934 * 1935 * @param counter the loop counter. 1936 * 1937 * @return the loop counter incremented by 1. 1938 */ 1939 static int countedLoopStep(int counter, int limit) { 1940 return counter + 1; 1941 } 1942 1943 /** 1944 * This method is bound as a filter in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, MethodHandle, 1945 * MethodHandle) counting loops} to pass the correct counter value to the body. 1946 * 1947 * @param counter the loop counter. 1948 * 1949 * @return the loop counter decremented by 1. 1950 */ 1951 static int decrementCounter(int counter) { 1952 return counter - 1; 1953 } 1954 1955 /** 1956 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}. 1957 * 1958 * @param it the {@link Iterable} over which the loop iterates. 1959 * 1960 * @return an {@link Iterator} over the argument's elements. 1961 */ 1962 static Iterator<?> initIterator(Iterable<?> it) { 1963 return it.iterator(); 1964 } 1965 1966 /** 1967 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}. 1968 * 1969 * @param it the iterator to be checked. 1970 * 1971 * @return {@code true} iff there are more elements to iterate over. 1972 */ 1973 static boolean iteratePredicate(Iterator<?> it) { 1974 return it.hasNext(); 1975 } 1976 1977 /** 1978 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain 1979 * MethodHandles#iteratedLoop iterating loops}. 1980 * 1981 * @param it the iterator. 1982 * 1983 * @return the next element from the iterator. 1984 */ 1985 static Object iterateNext(Iterator<?> it) { 1986 return it.next(); 1987 } 1988 1989 /** 1990 * Makes a {@code try-finally} handle that conforms to the type constraints. 1991 * 1992 * @param target the target to execute in a {@code try-finally} block. 1993 * @param cleanup the cleanup to execute in the {@code finally} block. 1994 * @param rtype the result type of the entire construct. 1995 * @param argTypes the types of the arguments. 1996 * 1997 * @return a handle on the constructed {@code try-finally} block. 1998 */ 1999 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, List<Class<?>> argTypes) { 2000 MethodType type = MethodType.methodType(rtype, argTypes); 2001 LambdaForm form = makeTryFinallyForm(type.basicType()); 2002 2003 // Prepare auxiliary method handles used during LambdaForm interpretation. 2004 // Box arguments and wrap them into Object[]: ValueConversions.array(). 2005 MethodType varargsType = type.changeReturnType(Object[].class); 2006 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType); 2007 MethodHandle unboxResult = unboxResultHandle(rtype); 2008 2009 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL(); 2010 BoundMethodHandle mh; 2011 try { 2012 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) cleanup, 2013 (Object) collectArgs, (Object) unboxResult); 2014 } catch (Throwable ex) { 2015 throw uncaughtException(ex); 2016 } 2017 assert(mh.type() == type); 2018 return mh; 2019 } 2020 2021 /** 2022 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in 2023 * {@code a1}, and a reference return type, with the return value represented by {@code t8}): 2024 * <blockquote><pre>{@code 2025 * tryFinally=Lambda(a0:L,a1:L)=>{ 2026 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle 2027 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle 2028 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[] 2029 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result 2030 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[] 2031 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor 2032 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result 2033 * }</pre></blockquote> 2034 * <p> 2035 * {@code argL0} and {@code argL1} are the target and cleanup method handles. 2036 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into 2037 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary 2038 * ({@code ValueConversions.unbox()}). 2039 * <p> 2040 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda 2041 * forms among tryFinally combinators with the same basic type. 2042 */ 2043 private static LambdaForm makeTryFinallyForm(MethodType basicType) { 2044 MethodType lambdaType = basicType.invokerType(); 2045 2046 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF); 2047 if (lform != null) { 2048 return lform; 2049 } 2050 final int THIS_MH = 0; // the BMH_LLLL 2051 final int ARG_BASE = 1; // start of incoming arguments 2052 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount(); 2053 2054 int nameCursor = ARG_LIMIT; 2055 final int GET_TARGET = nameCursor++; 2056 final int GET_CLEANUP = nameCursor++; 2057 final int GET_COLLECT_ARGS = nameCursor++; 2058 final int GET_UNBOX_RESULT = nameCursor++; 2059 final int BOXED_ARGS = nameCursor++; 2060 final int TRY_FINALLY = nameCursor++; 2061 final int UNBOX_RESULT = nameCursor++; 2062 2063 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType); 2064 2065 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL(); 2066 names[THIS_MH] = names[THIS_MH].withConstraint(data); 2067 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]); 2068 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]); 2069 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]); 2070 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]); 2071 2072 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...); 2073 MethodType collectArgsType = basicType.changeReturnType(Object.class); 2074 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType); 2075 Object[] args = new Object[invokeBasic.type().parameterCount()]; 2076 args[0] = names[GET_COLLECT_ARGS]; 2077 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE); 2078 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.TRY_FINALLY), args); 2079 2080 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L); 2081 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]}; 2082 names[TRY_FINALLY] = new Name(NF_tryFinally, tfArgs); 2083 2084 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L); 2085 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class)); 2086 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]}; 2087 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs); 2088 2089 lform = new LambdaForm("tryFinally", lambdaType.parameterCount(), names); 2090 2091 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform); 2092 } 2093 2094 /** 2095 * Intrinsified during LambdaForm compilation 2096 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}). 2097 */ 2098 @LambdaForm.Hidden 2099 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable { 2100 Throwable t = null; 2101 Object r = null; 2102 try { 2103 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case. 2104 r = target.asFixedArity().invokeWithArguments(av); 2105 } catch (Throwable thrown) { 2106 t = thrown; 2107 throw t; 2108 } finally { 2109 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r); 2110 r = cleanup.asFixedArity().invokeWithArguments(args); 2111 } 2112 return r; 2113 } 2114 2115 // Indexes into constant method handles: 2116 static final int 2117 MH_cast = 0, 2118 MH_selectAlternative = 1, 2119 MH_copyAsPrimitiveArray = 2, 2120 MH_fillNewTypedArray = 3, 2121 MH_fillNewArray = 4, 2122 MH_arrayIdentity = 5, 2123 MH_countedLoopPred = 6, 2124 MH_countedLoopStep = 7, 2125 MH_iteratePred = 8, 2126 MH_initIterator = 9, 2127 MH_iterateNext = 10, 2128 MH_decrementCounter = 11, 2129 MH_Array_newInstance = 12, 2130 MH_LIMIT = 13; 2131 2132 static MethodHandle getConstantHandle(int idx) { 2133 MethodHandle handle = HANDLES[idx]; 2134 if (handle != null) { 2135 return handle; 2136 } 2137 return setCachedHandle(idx, makeConstantHandle(idx)); 2138 } 2139 2140 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) { 2141 // Simulate a CAS, to avoid racy duplication of results. 2142 MethodHandle prev = HANDLES[idx]; 2143 if (prev != null) { 2144 return prev; 2145 } 2146 HANDLES[idx] = method; 2147 return method; 2148 } 2149 2150 // Local constant method handles: 2151 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT]; 2152 2153 private static MethodHandle makeConstantHandle(int idx) { 2154 try { 2155 switch (idx) { 2156 case MH_cast: 2157 return IMPL_LOOKUP.findVirtual(Class.class, "cast", 2158 MethodType.methodType(Object.class, Object.class)); 2159 case MH_copyAsPrimitiveArray: 2160 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray", 2161 MethodType.methodType(Object.class, Wrapper.class, Object[].class)); 2162 case MH_arrayIdentity: 2163 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity", 2164 MethodType.methodType(Object[].class, Object[].class)); 2165 case MH_fillNewArray: 2166 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray", 2167 MethodType.methodType(Object[].class, Integer.class, Object[].class)); 2168 case MH_fillNewTypedArray: 2169 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray", 2170 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class)); 2171 case MH_selectAlternative: 2172 return makeIntrinsic(IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative", 2173 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class)), 2174 Intrinsic.SELECT_ALTERNATIVE); 2175 case MH_countedLoopPred: 2176 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate", 2177 MethodType.methodType(boolean.class, int.class, int.class)); 2178 case MH_countedLoopStep: 2179 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep", 2180 MethodType.methodType(int.class, int.class, int.class)); 2181 case MH_iteratePred: 2182 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate", 2183 MethodType.methodType(boolean.class, Iterator.class)); 2184 case MH_initIterator: 2185 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator", 2186 MethodType.methodType(Iterator.class, Iterable.class)); 2187 case MH_iterateNext: 2188 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext", 2189 MethodType.methodType(Object.class, Iterator.class)); 2190 case MH_decrementCounter: 2191 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "decrementCounter", 2192 MethodType.methodType(int.class, int.class)); 2193 case MH_Array_newInstance: 2194 return IMPL_LOOKUP.findStatic(Array.class, "newInstance", 2195 MethodType.methodType(Object.class, Class.class, int.class)); 2196 } 2197 } catch (ReflectiveOperationException ex) { 2198 throw newInternalError(ex); 2199 } 2200 throw newInternalError("Unknown function index: " + idx); 2201 } 2202 }