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