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