1 /*
2 * Copyright (c) 2008, 2013, 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 java.security.AccessController;
29 import java.security.PrivilegedAction;
30 import java.util.ArrayList;
31 import java.util.Arrays;
32 import java.util.Collections;
33 import java.util.function.Function;
34
35 import sun.invoke.empty.Empty;
36 import sun.invoke.util.ValueConversions;
37 import sun.invoke.util.VerifyType;
38 import sun.invoke.util.Wrapper;
39 import jdk.internal.HotSpotIntrinsicCandidate;
40 import sun.reflect.CallerSensitive;
41 import sun.reflect.Reflection;
42 import static java.lang.invoke.LambdaForm.*;
43 import static java.lang.invoke.MethodHandleStatics.*;
44 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
45
46 /**
47 * Trusted implementation code for MethodHandle.
48 * @author jrose
49 */
50 /*non-public*/ abstract class MethodHandleImpl {
51 // Do not adjust this except for special platforms:
52 private static final int MAX_ARITY;
53 static {
54 final Object[] values = { 255 };
55 AccessController.doPrivileged(new PrivilegedAction<>() {
56 @Override
57 public Void run() {
58 values[0] = Integer.getInteger(MethodHandleImpl.class.getName()+".MAX_ARITY", 255);
59 return null;
60 }
61 });
62 MAX_ARITY = (Integer) values[0];
63 }
64
65 /// Factory methods to create method handles:
66
67 static void initStatics() {
68 // Trigger selected static initializations.
69 MemberName.Factory.INSTANCE.getClass();
70 }
71
72 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, boolean isSetter) {
73 if (arrayClass == Object[].class)
74 return (isSetter ? ArrayAccessor.OBJECT_ARRAY_SETTER : ArrayAccessor.OBJECT_ARRAY_GETTER);
75 if (!arrayClass.isArray())
76 throw newIllegalArgumentException("not an array: "+arrayClass);
77 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
78 int cacheIndex = (isSetter ? ArrayAccessor.SETTER_INDEX : ArrayAccessor.GETTER_INDEX);
79 MethodHandle mh = cache[cacheIndex];
80 if (mh != null) return mh;
81 mh = ArrayAccessor.getAccessor(arrayClass, isSetter);
82 MethodType correctType = ArrayAccessor.correctType(arrayClass, isSetter);
83 if (mh.type() != correctType) {
84 assert(mh.type().parameterType(0) == Object[].class);
85 assert((isSetter ? mh.type().parameterType(2) : mh.type().returnType()) == Object.class);
86 assert(isSetter || correctType.parameterType(0).getComponentType() == correctType.returnType());
87 // safe to view non-strictly, because element type follows from array type
88 mh = mh.viewAsType(correctType, false);
89 }
90 mh = makeIntrinsic(mh, (isSetter ? Intrinsic.ARRAY_STORE : Intrinsic.ARRAY_LOAD));
91 // Atomically update accessor cache.
92 synchronized(cache) {
93 if (cache[cacheIndex] == null) {
94 cache[cacheIndex] = mh;
95 } else {
96 // Throw away newly constructed accessor and use cached version.
97 mh = cache[cacheIndex];
98 }
99 }
100 return mh;
101 }
102
103 static final class ArrayAccessor {
104 /// Support for array element access
105 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, INDEX_LIMIT = 2;
106 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
107 = new ClassValue<MethodHandle[]>() {
108 @Override
109 protected MethodHandle[] computeValue(Class<?> type) {
110 return new MethodHandle[INDEX_LIMIT];
111 }
112 };
113 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER;
114 static {
115 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
116 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, false), Intrinsic.ARRAY_LOAD);
117 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, true), Intrinsic.ARRAY_STORE);
118
119 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
120 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
121 }
122
123 static int getElementI(int[] a, int i) { return a[i]; }
124 static long getElementJ(long[] a, int i) { return a[i]; }
125 static float getElementF(float[] a, int i) { return a[i]; }
126 static double getElementD(double[] a, int i) { return a[i]; }
127 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
128 static byte getElementB(byte[] a, int i) { return a[i]; }
129 static short getElementS(short[] a, int i) { return a[i]; }
130 static char getElementC(char[] a, int i) { return a[i]; }
131 static Object getElementL(Object[] a, int i) { return a[i]; }
132
133 static void setElementI(int[] a, int i, int x) { a[i] = x; }
134 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
135 static void setElementF(float[] a, int i, float x) { a[i] = x; }
136 static void setElementD(double[] a, int i, double x) { a[i] = x; }
137 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
138 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
139 static void setElementS(short[] a, int i, short x) { a[i] = x; }
140 static void setElementC(char[] a, int i, char x) { a[i] = x; }
141 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
142
143 static String name(Class<?> arrayClass, boolean isSetter) {
144 Class<?> elemClass = arrayClass.getComponentType();
145 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
146 return (!isSetter ? "getElement" : "setElement") + Wrapper.basicTypeChar(elemClass);
147 }
148 static MethodType type(Class<?> arrayClass, boolean isSetter) {
149 Class<?> elemClass = arrayClass.getComponentType();
150 Class<?> arrayArgClass = arrayClass;
151 if (!elemClass.isPrimitive()) {
152 arrayArgClass = Object[].class;
153 elemClass = Object.class;
154 }
155 return !isSetter ?
156 MethodType.methodType(elemClass, arrayArgClass, int.class) :
157 MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
158 }
159 static MethodType correctType(Class<?> arrayClass, boolean isSetter) {
160 Class<?> elemClass = arrayClass.getComponentType();
161 return !isSetter ?
162 MethodType.methodType(elemClass, arrayClass, int.class) :
163 MethodType.methodType(void.class, arrayClass, int.class, elemClass);
164 }
165 static MethodHandle getAccessor(Class<?> arrayClass, boolean isSetter) {
166 String name = name(arrayClass, isSetter);
167 MethodType type = type(arrayClass, isSetter);
168 try {
169 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
170 } catch (ReflectiveOperationException ex) {
171 throw uncaughtException(ex);
172 }
173 }
174 }
175
176 /**
177 * Create a JVM-level adapter method handle to conform the given method
178 * handle to the similar newType, using only pairwise argument conversions.
179 * For each argument, convert incoming argument to the exact type needed.
180 * The argument conversions allowed are casting, boxing and unboxing,
181 * integral widening or narrowing, and floating point widening or narrowing.
182 * @param srcType required call type
183 * @param target original method handle
184 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
185 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
186 * @return an adapter to the original handle with the desired new type,
187 * or the original target if the types are already identical
188 * or null if the adaptation cannot be made
189 */
190 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
191 boolean strict, boolean monobox) {
192 MethodType dstType = target.type();
193 if (srcType == dstType)
194 return target;
195 return makePairwiseConvertByEditor(target, srcType, strict, monobox);
196 }
197
198 private static int countNonNull(Object[] array) {
199 int count = 0;
200 for (Object x : array) {
201 if (x != null) ++count;
202 }
203 return count;
204 }
205
206 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
207 boolean strict, boolean monobox) {
208 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
209 int convCount = countNonNull(convSpecs);
210 if (convCount == 0)
211 return target.viewAsType(srcType, strict);
212 MethodType basicSrcType = srcType.basicType();
213 MethodType midType = target.type().basicType();
214 BoundMethodHandle mh = target.rebind();
215 // FIXME: Reduce number of bindings when there is more than one Class conversion.
216 // FIXME: Reduce number of bindings when there are repeated conversions.
217 for (int i = 0; i < convSpecs.length-1; i++) {
218 Object convSpec = convSpecs[i];
219 if (convSpec == null) continue;
220 MethodHandle fn;
221 if (convSpec instanceof Class) {
222 fn = Lazy.MH_castReference.bindTo(convSpec);
223 } else {
224 fn = (MethodHandle) convSpec;
225 }
226 Class<?> newType = basicSrcType.parameterType(i);
227 if (--convCount == 0)
228 midType = srcType;
229 else
230 midType = midType.changeParameterType(i, newType);
231 LambdaForm form2 = mh.editor().filterArgumentForm(1+i, BasicType.basicType(newType));
232 mh = mh.copyWithExtendL(midType, form2, fn);
233 mh = mh.rebind();
234 }
235 Object convSpec = convSpecs[convSpecs.length-1];
236 if (convSpec != null) {
237 MethodHandle fn;
238 if (convSpec instanceof Class) {
239 if (convSpec == void.class)
240 fn = null;
241 else
242 fn = Lazy.MH_castReference.bindTo(convSpec);
243 } else {
244 fn = (MethodHandle) convSpec;
245 }
246 Class<?> newType = basicSrcType.returnType();
247 assert(--convCount == 0);
248 midType = srcType;
249 if (fn != null) {
250 mh = mh.rebind(); // rebind if too complex
251 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
252 mh = mh.copyWithExtendL(midType, form2, fn);
253 } else {
254 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
255 mh = mh.copyWith(midType, form2);
256 }
257 }
258 assert(convCount == 0);
259 assert(mh.type().equals(srcType));
260 return mh;
261 }
262
263 static MethodHandle makePairwiseConvertIndirect(MethodHandle target, MethodType srcType,
264 boolean strict, boolean monobox) {
265 assert(target.type().parameterCount() == srcType.parameterCount());
266 // Calculate extra arguments (temporaries) required in the names array.
267 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
268 final int INARG_COUNT = srcType.parameterCount();
269 int convCount = countNonNull(convSpecs);
270 boolean retConv = (convSpecs[INARG_COUNT] != null);
271 boolean retVoid = srcType.returnType() == void.class;
272 if (retConv && retVoid) {
273 convCount -= 1;
274 retConv = false;
275 }
276
277 final int IN_MH = 0;
278 final int INARG_BASE = 1;
279 final int INARG_LIMIT = INARG_BASE + INARG_COUNT;
280 final int NAME_LIMIT = INARG_LIMIT + convCount + 1;
281 final int RETURN_CONV = (!retConv ? -1 : NAME_LIMIT - 1);
282 final int OUT_CALL = (!retConv ? NAME_LIMIT : RETURN_CONV) - 1;
283 final int RESULT = (retVoid ? -1 : NAME_LIMIT - 1);
284
285 // Now build a LambdaForm.
286 MethodType lambdaType = srcType.basicType().invokerType();
287 Name[] names = arguments(NAME_LIMIT - INARG_LIMIT, lambdaType);
288
289 // Collect the arguments to the outgoing call, maybe with conversions:
290 final int OUTARG_BASE = 0; // target MH is Name.function, name Name.arguments[0]
291 Object[] outArgs = new Object[OUTARG_BASE + INARG_COUNT];
292
293 int nameCursor = INARG_LIMIT;
294 for (int i = 0; i < INARG_COUNT; i++) {
295 Object convSpec = convSpecs[i];
296 if (convSpec == null) {
297 // do nothing: difference is trivial
298 outArgs[OUTARG_BASE + i] = names[INARG_BASE + i];
299 continue;
300 }
301
302 Name conv;
303 if (convSpec instanceof Class) {
304 Class<?> convClass = (Class<?>) convSpec;
305 conv = new Name(Lazy.MH_castReference, convClass, names[INARG_BASE + i]);
306 } else {
307 MethodHandle fn = (MethodHandle) convSpec;
308 conv = new Name(fn, names[INARG_BASE + i]);
309 }
310 assert(names[nameCursor] == null);
311 names[nameCursor++] = conv;
312 assert(outArgs[OUTARG_BASE + i] == null);
313 outArgs[OUTARG_BASE + i] = conv;
314 }
315
316 // Build argument array for the call.
317 assert(nameCursor == OUT_CALL);
318 names[OUT_CALL] = new Name(target, outArgs);
319
320 Object convSpec = convSpecs[INARG_COUNT];
321 if (!retConv) {
322 assert(OUT_CALL == names.length-1);
323 } else {
324 Name conv;
325 if (convSpec == void.class) {
326 conv = new Name(LambdaForm.constantZero(BasicType.basicType(srcType.returnType())));
327 } else if (convSpec instanceof Class) {
328 Class<?> convClass = (Class<?>) convSpec;
329 conv = new Name(Lazy.MH_castReference, convClass, names[OUT_CALL]);
330 } else {
331 MethodHandle fn = (MethodHandle) convSpec;
332 if (fn.type().parameterCount() == 0)
333 conv = new Name(fn); // don't pass retval to void conversion
334 else
335 conv = new Name(fn, names[OUT_CALL]);
336 }
337 assert(names[RETURN_CONV] == null);
338 names[RETURN_CONV] = conv;
339 assert(RETURN_CONV == names.length-1);
340 }
341
342 LambdaForm form = new LambdaForm("convert", lambdaType.parameterCount(), names, RESULT);
343 return SimpleMethodHandle.make(srcType, form);
344 }
345
346 /**
347 * Identity function, with reference cast.
348 * @param t an arbitrary reference type
349 * @param x an arbitrary reference value
350 * @return the same value x
351 */
352 @ForceInline
353 @SuppressWarnings("unchecked")
354 static <T,U> T castReference(Class<? extends T> t, U x) {
355 // inlined Class.cast because we can't ForceInline it
356 if (x != null && !t.isInstance(x))
357 throw newClassCastException(t, x);
358 return (T) x;
359 }
360
361 private static ClassCastException newClassCastException(Class<?> t, Object obj) {
362 return new ClassCastException("Cannot cast " + obj.getClass().getName() + " to " + t.getName());
363 }
364
365 static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
366 boolean strict, boolean monobox) {
367 final int INARG_COUNT = srcType.parameterCount();
368 Object[] convSpecs = new Object[INARG_COUNT+1];
369 for (int i = 0; i <= INARG_COUNT; i++) {
370 boolean isRet = (i == INARG_COUNT);
371 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
372 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
373 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
374 convSpecs[i] = valueConversion(src, dst, strict, monobox);
375 }
376 }
377 return convSpecs;
378 }
379 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
380 boolean strict) {
381 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
382 }
383
384 /**
385 * Find a conversion function from the given source to the given destination.
386 * This conversion function will be used as a LF NamedFunction.
387 * Return a Class object if a simple cast is needed.
388 * Return void.class if void is involved.
389 */
390 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
391 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
392 if (dst == void.class)
393 return dst;
394 MethodHandle fn;
395 if (src.isPrimitive()) {
396 if (src == void.class) {
397 return void.class; // caller must recognize this specially
398 } else if (dst.isPrimitive()) {
399 // Examples: int->byte, byte->int, boolean->int (!strict)
400 fn = ValueConversions.convertPrimitive(src, dst);
401 } else {
402 // Examples: int->Integer, boolean->Object, float->Number
403 Wrapper wsrc = Wrapper.forPrimitiveType(src);
404 fn = ValueConversions.boxExact(wsrc);
405 assert(fn.type().parameterType(0) == wsrc.primitiveType());
406 assert(fn.type().returnType() == wsrc.wrapperType());
407 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
408 // Corner case, such as int->Long, which will probably fail.
409 MethodType mt = MethodType.methodType(dst, src);
410 if (strict)
411 fn = fn.asType(mt);
412 else
413 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
414 }
415 }
416 } else if (dst.isPrimitive()) {
417 Wrapper wdst = Wrapper.forPrimitiveType(dst);
418 if (monobox || src == wdst.wrapperType()) {
419 // Use a strongly-typed unboxer, if possible.
420 fn = ValueConversions.unboxExact(wdst, strict);
421 } else {
422 // Examples: Object->int, Number->int, Comparable->int, Byte->int
423 // must include additional conversions
424 // src must be examined at runtime, to detect Byte, Character, etc.
425 fn = (strict
426 ? ValueConversions.unboxWiden(wdst)
427 : ValueConversions.unboxCast(wdst));
428 }
429 } else {
430 // Simple reference conversion.
431 // Note: Do not check for a class hierarchy relation
432 // between src and dst. In all cases a 'null' argument
433 // will pass the cast conversion.
434 return dst;
435 }
436 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
437 return fn;
438 }
439
440 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
441 MethodType type = target.type();
442 int last = type.parameterCount() - 1;
443 if (type.parameterType(last) != arrayType)
444 target = target.asType(type.changeParameterType(last, arrayType));
445 target = target.asFixedArity(); // make sure this attribute is turned off
446 return new AsVarargsCollector(target, arrayType);
447 }
448
449 private static final class AsVarargsCollector extends DelegatingMethodHandle {
450 private final MethodHandle target;
451 private final Class<?> arrayType;
452 private @Stable MethodHandle asCollectorCache;
453
454 AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
455 this(target.type(), target, arrayType);
456 }
457 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
458 super(type, target);
459 this.target = target;
460 this.arrayType = arrayType;
461 this.asCollectorCache = target.asCollector(arrayType, 0);
462 }
463
464 @Override
465 public boolean isVarargsCollector() {
466 return true;
467 }
468
469 @Override
470 protected MethodHandle getTarget() {
471 return target;
472 }
473
474 @Override
475 public MethodHandle asFixedArity() {
476 return target;
477 }
478
479 @Override
480 MethodHandle setVarargs(MemberName member) {
481 if (member.isVarargs()) return this;
482 return asFixedArity();
483 }
484
485 @Override
486 public MethodHandle asTypeUncached(MethodType newType) {
487 MethodType type = this.type();
488 int collectArg = type.parameterCount() - 1;
489 int newArity = newType.parameterCount();
490 if (newArity == collectArg+1 &&
491 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
492 // if arity and trailing parameter are compatible, do normal thing
493 return asTypeCache = asFixedArity().asType(newType);
494 }
495 // check cache
496 MethodHandle acc = asCollectorCache;
497 if (acc != null && acc.type().parameterCount() == newArity)
498 return asTypeCache = acc.asType(newType);
499 // build and cache a collector
500 int arrayLength = newArity - collectArg;
501 MethodHandle collector;
502 try {
503 collector = asFixedArity().asCollector(arrayType, arrayLength);
504 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
505 } catch (IllegalArgumentException ex) {
506 throw new WrongMethodTypeException("cannot build collector", ex);
507 }
508 asCollectorCache = collector;
509 return asTypeCache = collector.asType(newType);
510 }
511
512 @Override
513 boolean viewAsTypeChecks(MethodType newType, boolean strict) {
514 super.viewAsTypeChecks(newType, true);
515 if (strict) return true;
516 // extra assertion for non-strict checks:
517 assert (type().lastParameterType().getComponentType()
518 .isAssignableFrom(
519 newType.lastParameterType().getComponentType()))
520 : Arrays.asList(this, newType);
521 return true;
522 }
523 }
524
525 /** Factory method: Spread selected argument. */
526 static MethodHandle makeSpreadArguments(MethodHandle target,
527 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
528 MethodType targetType = target.type();
529
530 for (int i = 0; i < spreadArgCount; i++) {
531 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
532 if (arg == null) arg = Object.class;
533 targetType = targetType.changeParameterType(spreadArgPos + i, arg);
534 }
535 target = target.asType(targetType);
536
537 MethodType srcType = targetType
538 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
539 // Now build a LambdaForm.
540 MethodType lambdaType = srcType.invokerType();
541 Name[] names = arguments(spreadArgCount + 2, lambdaType);
542 int nameCursor = lambdaType.parameterCount();
543 int[] indexes = new int[targetType.parameterCount()];
544
545 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
546 Class<?> src = lambdaType.parameterType(i);
547 if (i == spreadArgPos) {
548 // Spread the array.
549 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
550 Name array = names[argIndex];
551 names[nameCursor++] = new Name(Lazy.NF_checkSpreadArgument, array, spreadArgCount);
552 for (int j = 0; j < spreadArgCount; i++, j++) {
553 indexes[i] = nameCursor;
554 names[nameCursor++] = new Name(aload, array, j);
555 }
556 } else if (i < indexes.length) {
557 indexes[i] = argIndex;
558 }
559 }
560 assert(nameCursor == names.length-1); // leave room for the final call
561
562 // Build argument array for the call.
563 Name[] targetArgs = new Name[targetType.parameterCount()];
564 for (int i = 0; i < targetType.parameterCount(); i++) {
565 int idx = indexes[i];
566 targetArgs[i] = names[idx];
567 }
568 names[names.length - 1] = new Name(target, (Object[]) targetArgs);
569
570 LambdaForm form = new LambdaForm("spread", lambdaType.parameterCount(), names);
571 return SimpleMethodHandle.make(srcType, form);
572 }
573
574 static void checkSpreadArgument(Object av, int n) {
575 if (av == null) {
576 if (n == 0) return;
577 } else if (av instanceof Object[]) {
578 int len = ((Object[])av).length;
579 if (len == n) return;
580 } else {
581 int len = java.lang.reflect.Array.getLength(av);
582 if (len == n) return;
583 }
584 // fall through to error:
585 throw newIllegalArgumentException("array is not of length "+n);
586 }
587
588 /**
589 * Pre-initialized NamedFunctions for bootstrapping purposes.
590 * Factored in an inner class to delay initialization until first usage.
591 */
592 static class Lazy {
593 private static final Class<?> MHI = MethodHandleImpl.class;
594
595 private static final MethodHandle[] ARRAYS;
596 private static final MethodHandle[] FILL_ARRAYS;
597
598 static final NamedFunction NF_checkSpreadArgument;
599 static final NamedFunction NF_guardWithCatch;
600 static final NamedFunction NF_throwException;
601 static final NamedFunction NF_profileBoolean;
602
603 static final MethodHandle MH_castReference;
604 static final MethodHandle MH_selectAlternative;
605 static final MethodHandle MH_copyAsPrimitiveArray;
606 static final MethodHandle MH_fillNewTypedArray;
607 static final MethodHandle MH_fillNewArray;
608 static final MethodHandle MH_arrayIdentity;
609
610 static {
611 ARRAYS = makeArrays();
612 FILL_ARRAYS = makeFillArrays();
613
614 try {
615 NF_checkSpreadArgument = new NamedFunction(MHI.getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
616 NF_guardWithCatch = new NamedFunction(MHI.getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
617 MethodHandle.class, Object[].class));
618 NF_throwException = new NamedFunction(MHI.getDeclaredMethod("throwException", Throwable.class));
619 NF_profileBoolean = new NamedFunction(MHI.getDeclaredMethod("profileBoolean", boolean.class, int[].class));
620
621 NF_checkSpreadArgument.resolve();
622 NF_guardWithCatch.resolve();
623 NF_throwException.resolve();
624 NF_profileBoolean.resolve();
625
626 MH_castReference = IMPL_LOOKUP.findStatic(MHI, "castReference",
627 MethodType.methodType(Object.class, Class.class, Object.class));
628 MH_copyAsPrimitiveArray = IMPL_LOOKUP.findStatic(MHI, "copyAsPrimitiveArray",
629 MethodType.methodType(Object.class, Wrapper.class, Object[].class));
630 MH_arrayIdentity = IMPL_LOOKUP.findStatic(MHI, "identity",
631 MethodType.methodType(Object[].class, Object[].class));
632 MH_fillNewArray = IMPL_LOOKUP.findStatic(MHI, "fillNewArray",
633 MethodType.methodType(Object[].class, Integer.class, Object[].class));
634 MH_fillNewTypedArray = IMPL_LOOKUP.findStatic(MHI, "fillNewTypedArray",
635 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class));
636
637 MH_selectAlternative = makeIntrinsic(
638 IMPL_LOOKUP.findStatic(MHI, "selectAlternative",
639 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class)),
640 Intrinsic.SELECT_ALTERNATIVE);
641 } catch (ReflectiveOperationException ex) {
642 throw newInternalError(ex);
643 }
644 }
645 }
646
647 /** Factory method: Collect or filter selected argument(s). */
648 static MethodHandle makeCollectArguments(MethodHandle target,
649 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
650 MethodType targetType = target.type(); // (a..., c, [b...])=>r
651 MethodType collectorType = collector.type(); // (b...)=>c
652 int collectArgCount = collectorType.parameterCount();
653 Class<?> collectValType = collectorType.returnType();
654 int collectValCount = (collectValType == void.class ? 0 : 1);
655 MethodType srcType = targetType // (a..., [b...])=>r
656 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
657 if (!retainOriginalArgs) { // (a..., b...)=>r
658 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterList());
659 }
660 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
661 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
662 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
663
664 // Now build a LambdaForm.
665 MethodType lambdaType = srcType.invokerType();
666 Name[] names = arguments(2, lambdaType);
667 final int collectNamePos = names.length - 2;
668 final int targetNamePos = names.length - 1;
669
670 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
671 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
672
673 // Build argument array for the target.
674 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
675 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
676 Name[] targetArgs = new Name[targetType.parameterCount()];
677 int inputArgPos = 1; // incoming LF args to copy to target
678 int targetArgPos = 0; // fill pointer for targetArgs
679 int chunk = collectArgPos; // |headArgs|
680 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
681 inputArgPos += chunk;
682 targetArgPos += chunk;
683 if (collectValType != void.class) {
684 targetArgs[targetArgPos++] = names[collectNamePos];
685 }
686 chunk = collectArgCount;
687 if (retainOriginalArgs) {
688 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
689 targetArgPos += chunk; // optionally pass on the collected chunk
690 }
691 inputArgPos += chunk;
692 chunk = targetArgs.length - targetArgPos; // all the rest
693 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
694 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
695 names[targetNamePos] = new Name(target, (Object[]) targetArgs);
696
697 LambdaForm form = new LambdaForm("collect", lambdaType.parameterCount(), names);
698 return SimpleMethodHandle.make(srcType, form);
699 }
700
701 @LambdaForm.Hidden
702 static
703 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
704 if (testResult) {
705 return target;
706 } else {
707 return fallback;
708 }
709 }
710
711 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
712 @LambdaForm.Hidden
713 @jdk.internal.HotSpotIntrinsicCandidate
714 static
715 boolean profileBoolean(boolean result, int[] counters) {
716 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
717 int idx = result ? 1 : 0;
718 try {
719 counters[idx] = Math.addExact(counters[idx], 1);
720 } catch (ArithmeticException e) {
721 // Avoid continuous overflow by halving the problematic count.
722 counters[idx] = counters[idx] / 2;
723 }
724 return result;
725 }
726
727 // Intrinsified by C2. Returns true if obj is a compile-time constant.
728 @LambdaForm.Hidden
729 @jdk.internal.HotSpotIntrinsicCandidate
730 static
731 boolean isCompileConstant(Object obj) {
732 return false;
733 }
734
735 static
736 MethodHandle makeGuardWithTest(MethodHandle test,
737 MethodHandle target,
738 MethodHandle fallback) {
739 MethodType type = target.type();
740 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
741 MethodType basicType = type.basicType();
742 LambdaForm form = makeGuardWithTestForm(basicType);
743 BoundMethodHandle mh;
744 try {
745 if (PROFILE_GWT) {
746 int[] counts = new int[2];
747 mh = (BoundMethodHandle)
748 BoundMethodHandle.speciesData_LLLL().constructor().invokeBasic(type, form,
749 (Object) test, (Object) profile(target), (Object) profile(fallback), counts);
750 } else {
751 mh = (BoundMethodHandle)
752 BoundMethodHandle.speciesData_LLL().constructor().invokeBasic(type, form,
753 (Object) test, (Object) profile(target), (Object) profile(fallback));
754 }
755 } catch (Throwable ex) {
756 throw uncaughtException(ex);
757 }
758 assert(mh.type() == type);
759 return mh;
760 }
761
762
763 static
764 MethodHandle profile(MethodHandle target) {
765 if (DONT_INLINE_THRESHOLD >= 0) {
766 return makeBlockInliningWrapper(target);
767 } else {
768 return target;
769 }
770 }
771
772 /**
773 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
774 * Corresponding LambdaForm has @DontInline when compiled into bytecode.
775 */
776 static
777 MethodHandle makeBlockInliningWrapper(MethodHandle target) {
778 LambdaForm lform;
779 if (DONT_INLINE_THRESHOLD > 0) {
780 lform = PRODUCE_BLOCK_INLINING_FORM.apply(target);
781 } else {
782 lform = PRODUCE_REINVOKER_FORM.apply(target);
783 }
784 return new CountingWrapper(target, lform,
785 PRODUCE_BLOCK_INLINING_FORM, PRODUCE_REINVOKER_FORM,
786 DONT_INLINE_THRESHOLD);
787 }
788
789 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
790 private static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
791 @Override
792 public LambdaForm apply(MethodHandle target) {
793 return DelegatingMethodHandle.makeReinvokerForm(target,
794 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, "reinvoker.dontInline", false,
795 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
796 }
797 };
798
799 /** Constructs simple reinvoker lambda form for a particular method handle */
800 private static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
801 @Override
802 public LambdaForm apply(MethodHandle target) {
803 return DelegatingMethodHandle.makeReinvokerForm(target,
804 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
805 }
806 };
807
808 /**
809 * Counting method handle. It has 2 states: counting and non-counting.
810 * It is in counting state for the first n invocations and then transitions to non-counting state.
811 * Behavior in counting and non-counting states is determined by lambda forms produced by
812 * countingFormProducer & nonCountingFormProducer respectively.
813 */
814 static class CountingWrapper extends DelegatingMethodHandle {
815 private final MethodHandle target;
816 private int count;
817 private Function<MethodHandle, LambdaForm> countingFormProducer;
818 private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
819 private volatile boolean isCounting;
820
821 private CountingWrapper(MethodHandle target, LambdaForm lform,
822 Function<MethodHandle, LambdaForm> countingFromProducer,
823 Function<MethodHandle, LambdaForm> nonCountingFormProducer,
824 int count) {
825 super(target.type(), lform);
826 this.target = target;
827 this.count = count;
828 this.countingFormProducer = countingFromProducer;
829 this.nonCountingFormProducer = nonCountingFormProducer;
830 this.isCounting = (count > 0);
831 }
832
833 @Hidden
834 @Override
835 protected MethodHandle getTarget() {
836 return target;
837 }
838
839 @Override
840 public MethodHandle asTypeUncached(MethodType newType) {
841 MethodHandle newTarget = target.asType(newType);
842 MethodHandle wrapper;
843 if (isCounting) {
844 LambdaForm lform;
845 lform = countingFormProducer.apply(newTarget);
846 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
847 } else {
848 wrapper = newTarget; // no need for a counting wrapper anymore
849 }
850 return (asTypeCache = wrapper);
851 }
852
853 boolean countDown() {
854 int c = count;
855 if (c <= 1) {
856 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
857 if (isCounting) {
858 isCounting = false;
859 return true;
860 } else {
861 return false;
862 }
863 } else {
864 count = c - 1;
865 return false;
866 }
867 }
868
869 @Hidden
870 static void maybeStopCounting(Object o1) {
871 CountingWrapper wrapper = (CountingWrapper) o1;
872 if (wrapper.countDown()) {
873 // Reached invocation threshold. Replace counting behavior with a non-counting one.
874 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
875 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
876 wrapper.updateForm(lform);
877 }
878 }
879
880 static final NamedFunction NF_maybeStopCounting;
881 static {
882 Class<?> THIS_CLASS = CountingWrapper.class;
883 try {
884 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
885 } catch (ReflectiveOperationException ex) {
886 throw newInternalError(ex);
887 }
888 }
889 }
890
891 static
892 LambdaForm makeGuardWithTestForm(MethodType basicType) {
893 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
894 if (lform != null) return lform;
895 final int THIS_MH = 0; // the BMH_LLL
896 final int ARG_BASE = 1; // start of incoming arguments
897 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
898 int nameCursor = ARG_LIMIT;
899 final int GET_TEST = nameCursor++;
900 final int GET_TARGET = nameCursor++;
901 final int GET_FALLBACK = nameCursor++;
902 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
903 final int CALL_TEST = nameCursor++;
904 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
905 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
906 final int SELECT_ALT = nameCursor++;
907 final int CALL_TARGET = nameCursor++;
908 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
909
910 MethodType lambdaType = basicType.invokerType();
911 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
912
913 BoundMethodHandle.SpeciesData data =
914 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
915 : BoundMethodHandle.speciesData_LLL();
916 names[THIS_MH] = names[THIS_MH].withConstraint(data);
917 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
918 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
919 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
920 if (GET_COUNTERS != -1) {
921 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
922 }
923 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
924
925 // call test
926 MethodType testType = basicType.changeReturnType(boolean.class).basicType();
927 invokeArgs[0] = names[GET_TEST];
928 names[CALL_TEST] = new Name(testType, invokeArgs);
929
930 // profile branch
931 if (PROFILE != -1) {
932 names[PROFILE] = new Name(Lazy.NF_profileBoolean, names[CALL_TEST], names[GET_COUNTERS]);
933 }
934 // call selectAlternative
935 names[SELECT_ALT] = new Name(Lazy.MH_selectAlternative, names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
936
937 // call target or fallback
938 invokeArgs[0] = names[SELECT_ALT];
939 names[CALL_TARGET] = new Name(basicType, invokeArgs);
940
941 lform = new LambdaForm("guard", lambdaType.parameterCount(), names, /*forceInline=*/true);
942
943 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
944 }
945
946 /**
947 * The LambdaForm shape for catchException combinator is the following:
948 * <blockquote><pre>{@code
949 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
950 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
951 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
952 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
953 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
954 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
955 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
956 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
957 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
958 * }</pre></blockquote>
959 *
960 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
961 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
962 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
963 *
964 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
965 * among catchException combinators with the same basic type.
966 */
967 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
968 MethodType lambdaType = basicType.invokerType();
969
970 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
971 if (lform != null) {
972 return lform;
973 }
974 final int THIS_MH = 0; // the BMH_LLLLL
975 final int ARG_BASE = 1; // start of incoming arguments
976 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
977
978 int nameCursor = ARG_LIMIT;
979 final int GET_TARGET = nameCursor++;
980 final int GET_CLASS = nameCursor++;
981 final int GET_CATCHER = nameCursor++;
982 final int GET_COLLECT_ARGS = nameCursor++;
983 final int GET_UNBOX_RESULT = nameCursor++;
984 final int BOXED_ARGS = nameCursor++;
985 final int TRY_CATCH = nameCursor++;
986 final int UNBOX_RESULT = nameCursor++;
987
988 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
989
990 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
991 names[THIS_MH] = names[THIS_MH].withConstraint(data);
992 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
993 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
994 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
995 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
996 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
997
998 // FIXME: rework argument boxing/result unboxing logic for LF interpretation
999
1000 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1001 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1002 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1003 Object[] args = new Object[invokeBasic.type().parameterCount()];
1004 args[0] = names[GET_COLLECT_ARGS];
1005 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
1006 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args);
1007
1008 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
1009 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
1010 names[TRY_CATCH] = new Name(Lazy.NF_guardWithCatch, gwcArgs);
1011
1012 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1013 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1014 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
1015 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1016
1017 lform = new LambdaForm("guardWithCatch", lambdaType.parameterCount(), names);
1018
1019 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
1020 }
1021
1022 static
1023 MethodHandle makeGuardWithCatch(MethodHandle target,
1024 Class<? extends Throwable> exType,
1025 MethodHandle catcher) {
1026 MethodType type = target.type();
1027 LambdaForm form = makeGuardWithCatchForm(type.basicType());
1028
1029 // Prepare auxiliary method handles used during LambdaForm interpretation.
1030 // Box arguments and wrap them into Object[]: ValueConversions.array().
1031 MethodType varargsType = type.changeReturnType(Object[].class);
1032 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1033 // Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore().
1034 MethodHandle unboxResult;
1035 Class<?> rtype = type.returnType();
1036 if (rtype.isPrimitive()) {
1037 if (rtype == void.class) {
1038 unboxResult = ValueConversions.ignore();
1039 } else {
1040 Wrapper w = Wrapper.forPrimitiveType(type.returnType());
1041 unboxResult = ValueConversions.unboxExact(w);
1042 }
1043 } else {
1044 unboxResult = MethodHandles.identity(Object.class);
1045 }
1046
1047 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
1048 BoundMethodHandle mh;
1049 try {
1050 mh = (BoundMethodHandle)
1051 data.constructor().invokeBasic(type, form, (Object) target, (Object) exType, (Object) catcher,
1052 (Object) collectArgs, (Object) unboxResult);
1053 } catch (Throwable ex) {
1054 throw uncaughtException(ex);
1055 }
1056 assert(mh.type() == type);
1057 return mh;
1058 }
1059
1060 /**
1061 * Intrinsified during LambdaForm compilation
1062 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
1063 */
1064 @LambdaForm.Hidden
1065 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
1066 Object... av) throws Throwable {
1067 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
1068 try {
1069 return target.asFixedArity().invokeWithArguments(av);
1070 } catch (Throwable t) {
1071 if (!exType.isInstance(t)) throw t;
1072 return catcher.asFixedArity().invokeWithArguments(prepend(t, av));
1073 }
1074 }
1075
1076 /** Prepend an element {@code elem} to an {@code array}. */
1077 @LambdaForm.Hidden
1078 private static Object[] prepend(Object elem, Object[] array) {
1079 Object[] newArray = new Object[array.length+1];
1080 newArray[0] = elem;
1081 System.arraycopy(array, 0, newArray, 1, array.length);
1082 return newArray;
1083 }
1084
1085 static
1086 MethodHandle throwException(MethodType type) {
1087 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
1088 int arity = type.parameterCount();
1089 if (arity > 1) {
1090 MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
1091 mh = MethodHandles.dropArguments(mh, 1, type.parameterList().subList(1, arity));
1092 return mh;
1093 }
1094 return makePairwiseConvert(Lazy.NF_throwException.resolvedHandle(), type, false, true);
1095 }
1096
1097 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
1098
1099 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
1100 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
1101 int idx;
1102 assert(method.isMethodHandleInvoke());
1103 switch (method.getName()) {
1104 case "invoke": idx = 0; break;
1105 case "invokeExact": idx = 1; break;
1106 default: throw new InternalError(method.getName());
1107 }
1108 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
1109 if (mh != null) return mh;
1110 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
1111 MethodHandle.class, Object[].class);
1112 mh = throwException(type);
1113 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
1114 if (!method.getInvocationType().equals(mh.type()))
1115 throw new InternalError(method.toString());
1116 mh = mh.withInternalMemberName(method, false);
1117 mh = mh.asVarargsCollector(Object[].class);
1118 assert(method.isVarargs());
1119 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
1120 return mh;
1121 }
1122
1123 /**
1124 * Create an alias for the method handle which, when called,
1125 * appears to be called from the same class loader and protection domain
1126 * as hostClass.
1127 * This is an expensive no-op unless the method which is called
1128 * is sensitive to its caller. A small number of system methods
1129 * are in this category, including Class.forName and Method.invoke.
1130 */
1131 static
1132 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1133 return BindCaller.bindCaller(mh, hostClass);
1134 }
1135
1136 // Put the whole mess into its own nested class.
1137 // That way we can lazily load the code and set up the constants.
1138 private static class BindCaller {
1139 static
1140 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1141 // Do not use this function to inject calls into system classes.
1142 if (hostClass == null
1143 || (hostClass.isArray() ||
1144 hostClass.isPrimitive() ||
1145 hostClass.getName().startsWith("java.") ||
1146 hostClass.getName().startsWith("sun."))) {
1147 throw new InternalError(); // does not happen, and should not anyway
1148 }
1149 // For simplicity, convert mh to a varargs-like method.
1150 MethodHandle vamh = prepareForInvoker(mh);
1151 // Cache the result of makeInjectedInvoker once per argument class.
1152 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
1153 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
1154 }
1155
1156 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) {
1157 Class<?> bcc = UNSAFE.defineAnonymousClass(hostClass, T_BYTES, null);
1158 if (hostClass.getClassLoader() != bcc.getClassLoader())
1159 throw new InternalError(hostClass.getName()+" (CL)");
1160 try {
1161 if (hostClass.getProtectionDomain() != bcc.getProtectionDomain())
1162 throw new InternalError(hostClass.getName()+" (PD)");
1163 } catch (SecurityException ex) {
1164 // Self-check was blocked by security manager. This is OK.
1165 // In fact the whole try body could be turned into an assertion.
1166 }
1167 try {
1168 MethodHandle init = IMPL_LOOKUP.findStatic(bcc, "init", MethodType.methodType(void.class));
1169 init.invokeExact(); // force initialization of the class
1170 } catch (Throwable ex) {
1171 throw uncaughtException(ex);
1172 }
1173 MethodHandle bccInvoker;
1174 try {
1175 MethodType invokerMT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1176 bccInvoker = IMPL_LOOKUP.findStatic(bcc, "invoke_V", invokerMT);
1177 } catch (ReflectiveOperationException ex) {
1178 throw uncaughtException(ex);
1179 }
1180 // Test the invoker, to ensure that it really injects into the right place.
1181 try {
1182 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
1183 Object ok = bccInvoker.invokeExact(vamh, new Object[]{hostClass, bcc});
1184 } catch (Throwable ex) {
1185 throw new InternalError(ex);
1186 }
1187 return bccInvoker;
1188 }
1189 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
1190 @Override protected MethodHandle computeValue(Class<?> hostClass) {
1191 return makeInjectedInvoker(hostClass);
1192 }
1193 };
1194
1195 // Adapt mh so that it can be called directly from an injected invoker:
1196 private static MethodHandle prepareForInvoker(MethodHandle mh) {
1197 mh = mh.asFixedArity();
1198 MethodType mt = mh.type();
1199 int arity = mt.parameterCount();
1200 MethodHandle vamh = mh.asType(mt.generic());
1201 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1202 vamh = vamh.asSpreader(Object[].class, arity);
1203 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1204 return vamh;
1205 }
1206
1207 // Undo the adapter effect of prepareForInvoker:
1208 private static MethodHandle restoreToType(MethodHandle vamh,
1209 MethodHandle original,
1210 Class<?> hostClass) {
1211 MethodType type = original.type();
1212 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
1213 MemberName member = original.internalMemberName();
1214 mh = mh.asType(type);
1215 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
1216 return mh;
1217 }
1218
1219 private static final MethodHandle MH_checkCallerClass;
1220 static {
1221 final Class<?> THIS_CLASS = BindCaller.class;
1222 assert(checkCallerClass(THIS_CLASS, THIS_CLASS));
1223 try {
1224 MH_checkCallerClass = IMPL_LOOKUP
1225 .findStatic(THIS_CLASS, "checkCallerClass",
1226 MethodType.methodType(boolean.class, Class.class, Class.class));
1227 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS, THIS_CLASS));
1228 } catch (Throwable ex) {
1229 throw new InternalError(ex);
1230 }
1231 }
1232
1233 @CallerSensitive
1234 private static boolean checkCallerClass(Class<?> expected, Class<?> expected2) {
1235 // This method is called via MH_checkCallerClass and so it's
1236 // correct to ask for the immediate caller here.
1237 Class<?> actual = Reflection.getCallerClass();
1238 if (actual != expected && actual != expected2)
1239 throw new InternalError("found "+actual.getName()+", expected "+expected.getName()
1240 +(expected == expected2 ? "" : ", or else "+expected2.getName()));
1241 return true;
1242 }
1243
1244 private static final byte[] T_BYTES;
1245 static {
1246 final Object[] values = {null};
1247 AccessController.doPrivileged(new PrivilegedAction<>() {
1248 public Void run() {
1249 try {
1250 Class<T> tClass = T.class;
1251 String tName = tClass.getName();
1252 String tResource = tName.substring(tName.lastIndexOf('.')+1)+".class";
1253 java.net.URLConnection uconn = tClass.getResource(tResource).openConnection();
1254 int len = uconn.getContentLength();
1255 byte[] bytes = new byte[len];
1256 try (java.io.InputStream str = uconn.getInputStream()) {
1257 int nr = str.read(bytes);
1258 if (nr != len) throw new java.io.IOException(tResource);
1259 }
1260 values[0] = bytes;
1261 } catch (java.io.IOException ex) {
1262 throw new InternalError(ex);
1263 }
1264 return null;
1265 }
1266 });
1267 T_BYTES = (byte[]) values[0];
1268 }
1269
1270 // The following class is used as a template for Unsafe.defineAnonymousClass:
1271 private static class T {
1272 static void init() { } // side effect: initializes this class
1273 static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
1274 return vamh.invokeExact(args);
1275 }
1276 }
1277 }
1278
1279
1280 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
1281 private static final class WrappedMember extends DelegatingMethodHandle {
1282 private final MethodHandle target;
1283 private final MemberName member;
1284 private final Class<?> callerClass;
1285 private final boolean isInvokeSpecial;
1286
1287 private WrappedMember(MethodHandle target, MethodType type,
1288 MemberName member, boolean isInvokeSpecial,
1289 Class<?> callerClass) {
1290 super(type, target);
1291 this.target = target;
1292 this.member = member;
1293 this.callerClass = callerClass;
1294 this.isInvokeSpecial = isInvokeSpecial;
1295 }
1296
1297 @Override
1298 MemberName internalMemberName() {
1299 return member;
1300 }
1301 @Override
1302 Class<?> internalCallerClass() {
1303 return callerClass;
1304 }
1305 @Override
1306 boolean isInvokeSpecial() {
1307 return isInvokeSpecial;
1308 }
1309 @Override
1310 protected MethodHandle getTarget() {
1311 return target;
1312 }
1313 @Override
1314 public MethodHandle asTypeUncached(MethodType newType) {
1315 // This MH is an alias for target, except for the MemberName
1316 // Drop the MemberName if there is any conversion.
1317 return asTypeCache = target.asType(newType);
1318 }
1319 }
1320
1321 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
1322 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
1323 return target;
1324 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
1325 }
1326
1327 /** Intrinsic IDs */
1328 /*non-public*/
1329 enum Intrinsic {
1330 SELECT_ALTERNATIVE,
1331 GUARD_WITH_CATCH,
1332 NEW_ARRAY,
1333 ARRAY_LOAD,
1334 ARRAY_STORE,
1335 IDENTITY,
1336 ZERO,
1337 NONE // no intrinsic associated
1338 }
1339
1340 /** Mark arbitrary method handle as intrinsic.
1341 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
1342 private static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
1343 private final MethodHandle target;
1344 private final Intrinsic intrinsicName;
1345
1346 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
1347 super(target.type(), target);
1348 this.target = target;
1349 this.intrinsicName = intrinsicName;
1350 }
1351
1352 @Override
1353 protected MethodHandle getTarget() {
1354 return target;
1355 }
1356
1357 @Override
1358 Intrinsic intrinsicName() {
1359 return intrinsicName;
1360 }
1361
1362 @Override
1363 public MethodHandle asTypeUncached(MethodType newType) {
1364 // This MH is an alias for target, except for the intrinsic name
1365 // Drop the name if there is any conversion.
1366 return asTypeCache = target.asType(newType);
1367 }
1368
1369 @Override
1370 String internalProperties() {
1371 return super.internalProperties() +
1372 "\n& Intrinsic="+intrinsicName;
1373 }
1374
1375 @Override
1376 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
1377 if (intrinsicName == Intrinsic.IDENTITY) {
1378 MethodType resultType = type().asCollectorType(arrayType, arrayLength);
1379 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
1380 return newArray.asType(resultType);
1381 }
1382 return super.asCollector(arrayType, arrayLength);
1383 }
1384 }
1385
1386 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
1387 if (intrinsicName == target.intrinsicName())
1388 return target;
1389 return new IntrinsicMethodHandle(target, intrinsicName);
1390 }
1391
1392 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
1393 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
1394 }
1395
1396 /// Collection of multiple arguments.
1397
1398 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) {
1399 MethodType type = MethodType.genericMethodType(nargs)
1400 .changeReturnType(rtype)
1401 .insertParameterTypes(0, ptypes);
1402 try {
1403 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type);
1404 } catch (ReflectiveOperationException ex) {
1405 return null;
1406 }
1407 }
1408
1409 private static final Object[] NO_ARGS_ARRAY = {};
1410 private static Object[] makeArray(Object... args) { return args; }
1411 private static Object[] array() { return NO_ARGS_ARRAY; }
1412 private static Object[] array(Object a0)
1413 { return makeArray(a0); }
1414 private static Object[] array(Object a0, Object a1)
1415 { return makeArray(a0, a1); }
1416 private static Object[] array(Object a0, Object a1, Object a2)
1417 { return makeArray(a0, a1, a2); }
1418 private static Object[] array(Object a0, Object a1, Object a2, Object a3)
1419 { return makeArray(a0, a1, a2, a3); }
1420 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1421 Object a4)
1422 { return makeArray(a0, a1, a2, a3, a4); }
1423 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1424 Object a4, Object a5)
1425 { return makeArray(a0, a1, a2, a3, a4, a5); }
1426 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1427 Object a4, Object a5, Object a6)
1428 { return makeArray(a0, a1, a2, a3, a4, a5, a6); }
1429 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1430 Object a4, Object a5, Object a6, Object a7)
1431 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); }
1432 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1433 Object a4, Object a5, Object a6, Object a7,
1434 Object a8)
1435 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); }
1436 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1437 Object a4, Object a5, Object a6, Object a7,
1438 Object a8, Object a9)
1439 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); }
1440
1441 private static final int ARRAYS_COUNT = 11;
1442
1443 private static MethodHandle[] makeArrays() {
1444 MethodHandle[] mhs = new MethodHandle[MAX_ARITY + 1];
1445 for (int i = 0; i < ARRAYS_COUNT; i++) {
1446 MethodHandle mh = findCollector("array", i, Object[].class);
1447 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1448 mhs[i] = mh;
1449 }
1450 assert(assertArrayMethodCount(mhs));
1451 return mhs;
1452 }
1453
1454 private static boolean assertArrayMethodCount(MethodHandle[] mhs) {
1455 assert(findCollector("array", ARRAYS_COUNT, Object[].class) == null);
1456 for (int i = 0; i < ARRAYS_COUNT; i++) {
1457 assert(mhs[i] != null);
1458 }
1459 return true;
1460 }
1461
1462 // filling versions of the above:
1463 // using Integer len instead of int len and no varargs to avoid bootstrapping problems
1464 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) {
1465 Object[] a = new Object[len];
1466 fillWithArguments(a, 0, args);
1467 return a;
1468 }
1469 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) {
1470 Object[] a = Arrays.copyOf(example, len);
1471 assert(a.getClass() != Object[].class);
1472 fillWithArguments(a, 0, args);
1473 return a;
1474 }
1475 private static void fillWithArguments(Object[] a, int pos, Object... args) {
1476 System.arraycopy(args, 0, a, pos, args.length);
1477 }
1478 // using Integer pos instead of int pos to avoid bootstrapping problems
1479 private static Object[] fillArray(Integer pos, Object[] a, Object a0)
1480 { fillWithArguments(a, pos, a0); return a; }
1481 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1)
1482 { fillWithArguments(a, pos, a0, a1); return a; }
1483 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2)
1484 { fillWithArguments(a, pos, a0, a1, a2); return a; }
1485 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3)
1486 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; }
1487 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1488 Object a4)
1489 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; }
1490 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1491 Object a4, Object a5)
1492 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; }
1493 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1494 Object a4, Object a5, Object a6)
1495 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; }
1496 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1497 Object a4, Object a5, Object a6, Object a7)
1498 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; }
1499 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1500 Object a4, Object a5, Object a6, Object a7,
1501 Object a8)
1502 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; }
1503 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1504 Object a4, Object a5, Object a6, Object a7,
1505 Object a8, Object a9)
1506 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; }
1507
1508 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods
1509
1510 private static MethodHandle[] makeFillArrays() {
1511 MethodHandle[] mhs = new MethodHandle[FILL_ARRAYS_COUNT];
1512 mhs[0] = null; // there is no empty fill; at least a0 is required
1513 for (int i = 1; i < FILL_ARRAYS_COUNT; i++) {
1514 MethodHandle mh = findCollector("fillArray", i, Object[].class, Integer.class, Object[].class);
1515 mhs[i] = mh;
1516 }
1517 assert(assertFillArrayMethodCount(mhs));
1518 return mhs;
1519 }
1520
1521 private static boolean assertFillArrayMethodCount(MethodHandle[] mhs) {
1522 assert(findCollector("fillArray", FILL_ARRAYS_COUNT, Object[].class, Integer.class, Object[].class) == null);
1523 for (int i = 1; i < FILL_ARRAYS_COUNT; i++) {
1524 assert(mhs[i] != null);
1525 }
1526 return true;
1527 }
1528
1529 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) {
1530 Object a = w.makeArray(boxes.length);
1531 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length);
1532 return a;
1533 }
1534
1535 /** Return a method handle that takes the indicated number of Object
1536 * arguments and returns an Object array of them, as if for varargs.
1537 */
1538 static MethodHandle varargsArray(int nargs) {
1539 MethodHandle mh = Lazy.ARRAYS[nargs];
1540 if (mh != null) return mh;
1541 mh = buildVarargsArray(Lazy.MH_fillNewArray, Lazy.MH_arrayIdentity, nargs);
1542 assert(assertCorrectArity(mh, nargs));
1543 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1544 return Lazy.ARRAYS[nargs] = mh;
1545 }
1546
1547 private static boolean assertCorrectArity(MethodHandle mh, int arity) {
1548 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
1549 return true;
1550 }
1551
1552 // Array identity function (used as Lazy.MH_arrayIdentity).
1553 static <T> T[] identity(T[] x) {
1554 return x;
1555 }
1556
1557 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) {
1558 // Build up the result mh as a sequence of fills like this:
1559 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23))
1560 // The various fill(_,10*I,___*[J]) are reusable.
1561 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately
1562 int rightLen = nargs - leftLen;
1563 MethodHandle leftCollector = newArray.bindTo(nargs);
1564 leftCollector = leftCollector.asCollector(Object[].class, leftLen);
1565 MethodHandle mh = finisher;
1566 if (rightLen > 0) {
1567 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen);
1568 if (mh == Lazy.MH_arrayIdentity)
1569 mh = rightFiller;
1570 else
1571 mh = MethodHandles.collectArguments(mh, 0, rightFiller);
1572 }
1573 if (mh == Lazy.MH_arrayIdentity)
1574 mh = leftCollector;
1575 else
1576 mh = MethodHandles.collectArguments(mh, 0, leftCollector);
1577 return mh;
1578 }
1579
1580 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1;
1581 private static final MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY+1];
1582 /** fill_array_to_right(N).invoke(a, argL..arg[N-1])
1583 * fills a[L]..a[N-1] with corresponding arguments,
1584 * and then returns a. The value L is a global constant (LEFT_ARGS).
1585 */
1586 private static MethodHandle fillToRight(int nargs) {
1587 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs];
1588 if (filler != null) return filler;
1589 filler = buildFiller(nargs);
1590 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1));
1591 return FILL_ARRAY_TO_RIGHT[nargs] = filler;
1592 }
1593 private static MethodHandle buildFiller(int nargs) {
1594 if (nargs <= LEFT_ARGS)
1595 return Lazy.MH_arrayIdentity; // no args to fill; return the array unchanged
1596 // we need room for both mh and a in mh.invoke(a, arg*[nargs])
1597 final int CHUNK = LEFT_ARGS;
1598 int rightLen = nargs % CHUNK;
1599 int midLen = nargs - rightLen;
1600 if (rightLen == 0) {
1601 midLen = nargs - (rightLen = CHUNK);
1602 if (FILL_ARRAY_TO_RIGHT[midLen] == null) {
1603 // build some precursors from left to right
1604 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK)
1605 if (j > LEFT_ARGS) fillToRight(j);
1606 }
1607 }
1608 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS);
1609 assert(rightLen > 0);
1610 MethodHandle midFill = fillToRight(midLen); // recursive fill
1611 MethodHandle rightFill = Lazy.FILL_ARRAYS[rightLen].bindTo(midLen); // [midLen..nargs-1]
1612 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS);
1613 assert(rightFill.type().parameterCount() == 1 + rightLen);
1614
1615 // Combine the two fills:
1616 // right(mid(a, x10..x19), x20..x23)
1617 // The final product will look like this:
1618 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23)
1619 if (midLen == LEFT_ARGS)
1620 return rightFill;
1621 else
1622 return MethodHandles.collectArguments(rightFill, 0, midFill);
1623 }
1624
1625 // Type-polymorphic version of varargs maker.
1626 private static final ClassValue<MethodHandle[]> TYPED_COLLECTORS
1627 = new ClassValue<MethodHandle[]>() {
1628 @Override
1629 protected MethodHandle[] computeValue(Class<?> type) {
1630 return new MethodHandle[256];
1631 }
1632 };
1633
1634 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
1635
1636 /** Return a method handle that takes the indicated number of
1637 * typed arguments and returns an array of them.
1638 * The type argument is the array type.
1639 */
1640 static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
1641 Class<?> elemType = arrayType.getComponentType();
1642 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
1643 // FIXME: Need more special casing and caching here.
1644 if (nargs >= MAX_JVM_ARITY/2 - 1) {
1645 int slots = nargs;
1646 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
1647 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
1648 slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
1649 if (slots > MAX_ARRAY_SLOTS)
1650 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
1651 }
1652 if (elemType == Object.class)
1653 return varargsArray(nargs);
1654 // other cases: primitive arrays, subtypes of Object[]
1655 MethodHandle cache[] = TYPED_COLLECTORS.get(elemType);
1656 MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
1657 if (mh != null) return mh;
1658 if (nargs == 0) {
1659 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0);
1660 mh = MethodHandles.constant(arrayType, example);
1661 } else if (elemType.isPrimitive()) {
1662 MethodHandle builder = Lazy.MH_fillNewArray;
1663 MethodHandle producer = buildArrayProducer(arrayType);
1664 mh = buildVarargsArray(builder, producer, nargs);
1665 } else {
1666 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class);
1667 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType);
1668 MethodHandle builder = Lazy.MH_fillNewTypedArray.bindTo(example);
1669 MethodHandle producer = Lazy.MH_arrayIdentity; // must be weakly typed
1670 mh = buildVarargsArray(builder, producer, nargs);
1671 }
1672 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)));
1673 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1674 assert(assertCorrectArity(mh, nargs));
1675 if (nargs < cache.length)
1676 cache[nargs] = mh;
1677 return mh;
1678 }
1679
1680 private static MethodHandle buildArrayProducer(Class<?> arrayType) {
1681 Class<?> elemType = arrayType.getComponentType();
1682 assert(elemType.isPrimitive());
1683 return Lazy.MH_copyAsPrimitiveArray.bindTo(Wrapper.forPrimitiveType(elemType));
1684 }
1685
1686 /*non-public*/ static void assertSame(Object mh1, Object mh2) {
1687 if (mh1 != mh2) {
1688 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)",
1689 mh1, ((MethodHandle)mh1).form,
1690 mh2, ((MethodHandle)mh2).form);
1691 throw newInternalError(msg);
1692 }
1693 }
1694 }