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