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