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