1 /*
2 * Copyright (c) 2008, 2018, 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 jdk.internal.access.JavaLangInvokeAccess;
29 import jdk.internal.access.SharedSecrets;
30 import jdk.internal.org.objectweb.asm.ClassWriter;
31 import jdk.internal.org.objectweb.asm.MethodVisitor;
32 import jdk.internal.reflect.CallerSensitive;
33 import jdk.internal.reflect.Reflection;
34 import jdk.internal.vm.annotation.ForceInline;
35 import jdk.internal.vm.annotation.Hidden;
36 import jdk.internal.vm.annotation.Stable;
37 import sun.invoke.empty.Empty;
38 import sun.invoke.util.ValueConversions;
39 import sun.invoke.util.VerifyType;
40 import sun.invoke.util.Wrapper;
41
42 import java.lang.invoke.MethodHandles.Lookup;
43 import java.lang.reflect.Array;
44 import java.nio.ByteOrder;
45 import java.util.Arrays;
46 import java.util.Collections;
47 import java.util.HashMap;
48 import java.util.Iterator;
49 import java.util.List;
50 import java.util.Map;
51 import java.util.function.Function;
52 import java.util.stream.Stream;
53
54 import static java.lang.invoke.LambdaForm.*;
55 import static java.lang.invoke.MethodHandleStatics.*;
56 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
57 import static java.lang.invoke.MethodHandleNatives.Constants.HIDDEN_CLASS;
58 import static jdk.internal.org.objectweb.asm.Opcodes.*;
59
60 /**
61 * Trusted implementation code for MethodHandle.
62 * @author jrose
63 */
64 /*non-public*/
65 abstract class MethodHandleImpl {
66
67 /// Factory methods to create method handles:
68
69 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, ArrayAccess access) {
70 if (arrayClass == Object[].class) {
71 return ArrayAccess.objectAccessor(access);
72 }
73 if (!arrayClass.isArray())
74 throw newIllegalArgumentException("not an array: "+arrayClass);
75 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
76 int cacheIndex = ArrayAccess.cacheIndex(access);
77 MethodHandle mh = cache[cacheIndex];
78 if (mh != null) return mh;
79 mh = ArrayAccessor.getAccessor(arrayClass, access);
80 MethodType correctType = ArrayAccessor.correctType(arrayClass, access);
81 if (mh.type() != correctType) {
82 assert(mh.type().parameterType(0) == Object[].class);
83 /* if access == SET */ assert(access != ArrayAccess.SET || mh.type().parameterType(2) == Object.class);
84 /* if access == GET */ assert(access != ArrayAccess.GET ||
85 (mh.type().returnType() == Object.class &&
86 correctType.parameterType(0).getComponentType() == correctType.returnType()));
87 // safe to view non-strictly, because element type follows from array type
88 mh = mh.viewAsType(correctType, false);
89 }
90 mh = makeIntrinsic(mh, ArrayAccess.intrinsic(access));
91 // Atomically update accessor cache.
92 synchronized(cache) {
93 if (cache[cacheIndex] == null) {
94 cache[cacheIndex] = mh;
95 } else {
96 // Throw away newly constructed accessor and use cached version.
97 mh = cache[cacheIndex];
98 }
99 }
100 return mh;
101 }
102
103 enum ArrayAccess {
104 GET, SET, LENGTH;
105
106 // As ArrayAccess and ArrayAccessor have a circular dependency, the ArrayAccess properties cannot be stored in
107 // final fields.
108
109 static String opName(ArrayAccess a) {
110 switch (a) {
111 case GET: return "getElement";
112 case SET: return "setElement";
113 case LENGTH: return "length";
114 }
115 throw unmatchedArrayAccess(a);
116 }
117
118 static MethodHandle objectAccessor(ArrayAccess a) {
119 switch (a) {
120 case GET: return ArrayAccessor.OBJECT_ARRAY_GETTER;
121 case SET: return ArrayAccessor.OBJECT_ARRAY_SETTER;
122 case LENGTH: return ArrayAccessor.OBJECT_ARRAY_LENGTH;
123 }
124 throw unmatchedArrayAccess(a);
125 }
126
127 static int cacheIndex(ArrayAccess a) {
128 switch (a) {
129 case GET: return ArrayAccessor.GETTER_INDEX;
130 case SET: return ArrayAccessor.SETTER_INDEX;
131 case LENGTH: return ArrayAccessor.LENGTH_INDEX;
132 }
133 throw unmatchedArrayAccess(a);
134 }
135
136 static Intrinsic intrinsic(ArrayAccess a) {
137 switch (a) {
138 case GET: return Intrinsic.ARRAY_LOAD;
139 case SET: return Intrinsic.ARRAY_STORE;
140 case LENGTH: return Intrinsic.ARRAY_LENGTH;
141 }
142 throw unmatchedArrayAccess(a);
143 }
144 }
145
146 static InternalError unmatchedArrayAccess(ArrayAccess a) {
147 return newInternalError("should not reach here (unmatched ArrayAccess: " + a + ")");
148 }
149
150 static final class ArrayAccessor {
151 /// Support for array element and length access
152 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, LENGTH_INDEX = 2, INDEX_LIMIT = 3;
153 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
154 = new ClassValue<MethodHandle[]>() {
155 @Override
156 protected MethodHandle[] computeValue(Class<?> type) {
157 return new MethodHandle[INDEX_LIMIT];
158 }
159 };
160 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER, OBJECT_ARRAY_LENGTH;
161 static {
162 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
163 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.GET), Intrinsic.ARRAY_LOAD);
164 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.SET), Intrinsic.ARRAY_STORE);
165 cache[LENGTH_INDEX] = OBJECT_ARRAY_LENGTH = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.LENGTH), Intrinsic.ARRAY_LENGTH);
166
167 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
168 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
169 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_LENGTH.internalMemberName()));
170 }
171
172 static int getElementI(int[] a, int i) { return a[i]; }
173 static long getElementJ(long[] a, int i) { return a[i]; }
174 static float getElementF(float[] a, int i) { return a[i]; }
175 static double getElementD(double[] a, int i) { return a[i]; }
176 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
177 static byte getElementB(byte[] a, int i) { return a[i]; }
178 static short getElementS(short[] a, int i) { return a[i]; }
179 static char getElementC(char[] a, int i) { return a[i]; }
180 static Object getElementL(Object[] a, int i) { return a[i]; }
181
182 static void setElementI(int[] a, int i, int x) { a[i] = x; }
183 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
184 static void setElementF(float[] a, int i, float x) { a[i] = x; }
185 static void setElementD(double[] a, int i, double x) { a[i] = x; }
186 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
187 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
188 static void setElementS(short[] a, int i, short x) { a[i] = x; }
189 static void setElementC(char[] a, int i, char x) { a[i] = x; }
190 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
191
192 static int lengthI(int[] a) { return a.length; }
193 static int lengthJ(long[] a) { return a.length; }
194 static int lengthF(float[] a) { return a.length; }
195 static int lengthD(double[] a) { return a.length; }
196 static int lengthZ(boolean[] a) { return a.length; }
197 static int lengthB(byte[] a) { return a.length; }
198 static int lengthS(short[] a) { return a.length; }
199 static int lengthC(char[] a) { return a.length; }
200 static int lengthL(Object[] a) { return a.length; }
201
202 static String name(Class<?> arrayClass, ArrayAccess access) {
203 Class<?> elemClass = arrayClass.getComponentType();
204 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
205 return ArrayAccess.opName(access) + Wrapper.basicTypeChar(elemClass);
206 }
207 static MethodType type(Class<?> arrayClass, ArrayAccess access) {
208 Class<?> elemClass = arrayClass.getComponentType();
209 Class<?> arrayArgClass = arrayClass;
210 if (!elemClass.isPrimitive()) {
211 arrayArgClass = Object[].class;
212 elemClass = Object.class;
213 }
214 switch (access) {
215 case GET: return MethodType.methodType(elemClass, arrayArgClass, int.class);
216 case SET: return MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
217 case LENGTH: return MethodType.methodType(int.class, arrayArgClass);
218 }
219 throw unmatchedArrayAccess(access);
220 }
221 static MethodType correctType(Class<?> arrayClass, ArrayAccess access) {
222 Class<?> elemClass = arrayClass.getComponentType();
223 switch (access) {
224 case GET: return MethodType.methodType(elemClass, arrayClass, int.class);
225 case SET: return MethodType.methodType(void.class, arrayClass, int.class, elemClass);
226 case LENGTH: return MethodType.methodType(int.class, arrayClass);
227 }
228 throw unmatchedArrayAccess(access);
229 }
230 static MethodHandle getAccessor(Class<?> arrayClass, ArrayAccess access) {
231 String name = name(arrayClass, access);
232 MethodType type = type(arrayClass, access);
233 try {
234 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
235 } catch (ReflectiveOperationException ex) {
236 throw uncaughtException(ex);
237 }
238 }
239 }
240
241 /**
242 * Create a JVM-level adapter method handle to conform the given method
243 * handle to the similar newType, using only pairwise argument conversions.
244 * For each argument, convert incoming argument to the exact type needed.
245 * The argument conversions allowed are casting, boxing and unboxing,
246 * integral widening or narrowing, and floating point widening or narrowing.
247 * @param srcType required call type
248 * @param target original method handle
249 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
250 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
251 * @return an adapter to the original handle with the desired new type,
252 * or the original target if the types are already identical
253 * or null if the adaptation cannot be made
254 */
255 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
256 boolean strict, boolean monobox) {
257 MethodType dstType = target.type();
258 if (srcType == dstType)
259 return target;
260 return makePairwiseConvertByEditor(target, srcType, strict, monobox);
261 }
262
263 private static int countNonNull(Object[] array) {
264 int count = 0;
265 if (array != null) {
266 for (Object x : array) {
267 if (x != null) ++count;
268 }
269 }
270 return count;
271 }
272
273 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
274 boolean strict, boolean monobox) {
275 // In method types arguments start at index 0, while the LF
276 // editor have the MH receiver at position 0 - adjust appropriately.
277 final int MH_RECEIVER_OFFSET = 1;
278 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
279 int convCount = countNonNull(convSpecs);
280 if (convCount == 0)
281 return target.viewAsType(srcType, strict);
282 MethodType basicSrcType = srcType.basicType();
283 MethodType midType = target.type().basicType();
284 BoundMethodHandle mh = target.rebind();
285
286 // Match each unique conversion to the positions at which it is to be applied
287 var convSpecMap = new HashMap<Object, int[]>(((4 * convCount) / 3) + 1);
288 for (int i = 0; i < convSpecs.length - MH_RECEIVER_OFFSET; i++) {
289 Object convSpec = convSpecs[i];
290 if (convSpec == null) continue;
291 int[] positions = convSpecMap.get(convSpec);
292 if (positions == null) {
293 positions = new int[] { i + MH_RECEIVER_OFFSET };
294 } else {
295 positions = Arrays.copyOf(positions, positions.length + 1);
296 positions[positions.length - 1] = i + MH_RECEIVER_OFFSET;
297 }
298 convSpecMap.put(convSpec, positions);
299 }
300 for (var entry : convSpecMap.entrySet()) {
301 Object convSpec = entry.getKey();
302
303 MethodHandle fn;
304 if (convSpec instanceof Class) {
305 fn = getConstantHandle(MH_cast).bindTo(convSpec);
306 } else {
307 fn = (MethodHandle) convSpec;
308 }
309 int[] positions = entry.getValue();
310 Class<?> newType = basicSrcType.parameterType(positions[0] - MH_RECEIVER_OFFSET);
311 BasicType newBasicType = BasicType.basicType(newType);
312 convCount -= positions.length;
313 if (convCount == 0) {
314 midType = srcType;
315 } else {
316 Class<?>[] ptypes = midType.ptypes().clone();
317 for (int pos : positions) {
318 ptypes[pos - 1] = newType;
319 }
320 midType = MethodType.makeImpl(midType.rtype(), ptypes, true);
321 }
322 LambdaForm form2;
323 if (positions.length > 1) {
324 form2 = mh.editor().filterRepeatedArgumentForm(newBasicType, positions);
325 } else {
326 form2 = mh.editor().filterArgumentForm(positions[0], newBasicType);
327 }
328 mh = mh.copyWithExtendL(midType, form2, fn);
329 }
330 Object convSpec = convSpecs[convSpecs.length - 1];
331 if (convSpec != null) {
332 MethodHandle fn;
333 if (convSpec instanceof Class) {
334 if (convSpec == void.class)
335 fn = null;
336 else
337 fn = getConstantHandle(MH_cast).bindTo(convSpec);
338 } else {
339 fn = (MethodHandle) convSpec;
340 }
341 Class<?> newType = basicSrcType.returnType();
342 assert(--convCount == 0);
343 midType = srcType;
344 if (fn != null) {
345 mh = mh.rebind(); // rebind if too complex
346 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
347 mh = mh.copyWithExtendL(midType, form2, fn);
348 } else {
349 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
350 mh = mh.copyWith(midType, form2);
351 }
352 }
353 assert(convCount == 0);
354 assert(mh.type().equals(srcType));
355 return mh;
356 }
357
358 static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
359 boolean strict, boolean monobox) {
360 final int INARG_COUNT = srcType.parameterCount();
361 Object[] convSpecs = null;
362 for (int i = 0; i <= INARG_COUNT; i++) {
363 boolean isRet = (i == INARG_COUNT);
364 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
365 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
366 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
367 if (convSpecs == null) {
368 convSpecs = new Object[INARG_COUNT + 1];
369 }
370 convSpecs[i] = valueConversion(src, dst, strict, monobox);
371 }
372 }
373 return convSpecs;
374 }
375 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
376 boolean strict) {
377 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
378 }
379
380 /**
381 * Find a conversion function from the given source to the given destination.
382 * This conversion function will be used as a LF NamedFunction.
383 * Return a Class object if a simple cast is needed.
384 * Return void.class if void is involved.
385 */
386 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
387 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
388 if (dst == void.class)
389 return dst;
390 MethodHandle fn;
391 if (src.isPrimitive()) {
392 if (src == void.class) {
393 return void.class; // caller must recognize this specially
394 } else if (dst.isPrimitive()) {
395 // Examples: int->byte, byte->int, boolean->int (!strict)
396 fn = ValueConversions.convertPrimitive(src, dst);
397 } else {
398 // Examples: int->Integer, boolean->Object, float->Number
399 Wrapper wsrc = Wrapper.forPrimitiveType(src);
400 fn = ValueConversions.boxExact(wsrc);
401 assert(fn.type().parameterType(0) == wsrc.primitiveType());
402 assert(fn.type().returnType() == wsrc.wrapperType());
403 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
404 // Corner case, such as int->Long, which will probably fail.
405 MethodType mt = MethodType.methodType(dst, src);
406 if (strict)
407 fn = fn.asType(mt);
408 else
409 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
410 }
411 }
412 } else if (dst.isPrimitive()) {
413 Wrapper wdst = Wrapper.forPrimitiveType(dst);
414 if (monobox || src == wdst.wrapperType()) {
415 // Use a strongly-typed unboxer, if possible.
416 fn = ValueConversions.unboxExact(wdst, strict);
417 } else {
418 // Examples: Object->int, Number->int, Comparable->int, Byte->int
419 // must include additional conversions
420 // src must be examined at runtime, to detect Byte, Character, etc.
421 fn = (strict
422 ? ValueConversions.unboxWiden(wdst)
423 : ValueConversions.unboxCast(wdst));
424 }
425 } else {
426 // Simple reference conversion.
427 // Note: Do not check for a class hierarchy relation
428 // between src and dst. In all cases a 'null' argument
429 // will pass the cast conversion.
430 return dst;
431 }
432 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
433 return fn;
434 }
435
436 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
437 MethodType type = target.type();
438 int last = type.parameterCount() - 1;
439 if (type.parameterType(last) != arrayType)
440 target = target.asType(type.changeParameterType(last, arrayType));
441 target = target.asFixedArity(); // make sure this attribute is turned off
442 return new AsVarargsCollector(target, arrayType);
443 }
444
445 private static final class AsVarargsCollector extends DelegatingMethodHandle {
446 private final MethodHandle target;
447 private final Class<?> arrayType;
448 private @Stable MethodHandle asCollectorCache;
449
450 AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
451 this(target.type(), target, arrayType);
452 }
453 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
454 super(type, target);
455 this.target = target;
456 this.arrayType = arrayType;
457 }
458
459 @Override
460 public boolean isVarargsCollector() {
461 return true;
462 }
463
464 @Override
465 protected MethodHandle getTarget() {
466 return target;
467 }
468
469 @Override
470 public MethodHandle asFixedArity() {
471 return target;
472 }
473
474 @Override
475 MethodHandle setVarargs(MemberName member) {
476 if (member.isVarargs()) return this;
477 return asFixedArity();
478 }
479
480 @Override
481 public MethodHandle withVarargs(boolean makeVarargs) {
482 if (makeVarargs) return this;
483 return asFixedArity();
484 }
485
486 @Override
487 public MethodHandle asTypeUncached(MethodType newType) {
488 MethodType type = this.type();
489 int collectArg = type.parameterCount() - 1;
490 int newArity = newType.parameterCount();
491 if (newArity == collectArg+1 &&
492 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
493 // if arity and trailing parameter are compatible, do normal thing
494 return asTypeCache = asFixedArity().asType(newType);
495 }
496 // check cache
497 MethodHandle acc = asCollectorCache;
498 if (acc != null && acc.type().parameterCount() == newArity)
499 return asTypeCache = acc.asType(newType);
500 // build and cache a collector
501 int arrayLength = newArity - collectArg;
502 MethodHandle collector;
503 try {
504 collector = asFixedArity().asCollector(arrayType, arrayLength);
505 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
506 } catch (IllegalArgumentException ex) {
507 throw new WrongMethodTypeException("cannot build collector", ex);
508 }
509 asCollectorCache = collector;
510 return asTypeCache = collector.asType(newType);
511 }
512
513 @Override
514 boolean viewAsTypeChecks(MethodType newType, boolean strict) {
515 super.viewAsTypeChecks(newType, true);
516 if (strict) return true;
517 // extra assertion for non-strict checks:
518 assert (type().lastParameterType().getComponentType()
519 .isAssignableFrom(
520 newType.lastParameterType().getComponentType()))
521 : Arrays.asList(this, newType);
522 return true;
523 }
524
525 @Override
526 public Object invokeWithArguments(Object... arguments) throws Throwable {
527 MethodType type = this.type();
528 int argc;
529 final int MAX_SAFE = 127; // 127 longs require 254 slots, which is safe to spread
530 if (arguments == null
531 || (argc = arguments.length) <= MAX_SAFE
532 || argc < type.parameterCount()) {
533 return super.invokeWithArguments(arguments);
534 }
535
536 // a jumbo invocation requires more explicit reboxing of the trailing arguments
537 int uncollected = type.parameterCount() - 1;
538 Class<?> elemType = arrayType.getComponentType();
539 int collected = argc - uncollected;
540 Object collArgs = (elemType == Object.class)
541 ? new Object[collected] : Array.newInstance(elemType, collected);
542 if (!elemType.isPrimitive()) {
543 // simple cast: just do some casting
544 try {
545 System.arraycopy(arguments, uncollected, collArgs, 0, collected);
546 } catch (ArrayStoreException ex) {
547 return super.invokeWithArguments(arguments);
548 }
549 } else {
550 // corner case of flat array requires reflection (or specialized copy loop)
551 MethodHandle arraySetter = MethodHandles.arrayElementSetter(arrayType);
552 try {
553 for (int i = 0; i < collected; i++) {
554 arraySetter.invoke(collArgs, i, arguments[uncollected + i]);
555 }
556 } catch (WrongMethodTypeException|ClassCastException ex) {
557 return super.invokeWithArguments(arguments);
558 }
559 }
560
561 // chop the jumbo list down to size and call in non-varargs mode
562 Object[] newArgs = new Object[uncollected + 1];
563 System.arraycopy(arguments, 0, newArgs, 0, uncollected);
564 newArgs[uncollected] = collArgs;
565 return asFixedArity().invokeWithArguments(newArgs);
566 }
567 }
568
569 /** Factory method: Spread selected argument. */
570 static MethodHandle makeSpreadArguments(MethodHandle target,
571 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
572 MethodType targetType = target.type();
573
574 for (int i = 0; i < spreadArgCount; i++) {
575 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
576 if (arg == null) arg = Object.class;
577 targetType = targetType.changeParameterType(spreadArgPos + i, arg);
578 }
579 target = target.asType(targetType);
580
581 MethodType srcType = targetType
582 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
583 // Now build a LambdaForm.
584 MethodType lambdaType = srcType.invokerType();
585 Name[] names = arguments(spreadArgCount + 2, lambdaType);
586 int nameCursor = lambdaType.parameterCount();
587 int[] indexes = new int[targetType.parameterCount()];
588
589 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
590 Class<?> src = lambdaType.parameterType(i);
591 if (i == spreadArgPos) {
592 // Spread the array.
593 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
594 Name array = names[argIndex];
595 names[nameCursor++] = new Name(getFunction(NF_checkSpreadArgument), array, spreadArgCount);
596 for (int j = 0; j < spreadArgCount; i++, j++) {
597 indexes[i] = nameCursor;
598 names[nameCursor++] = new Name(new NamedFunction(aload, Intrinsic.ARRAY_LOAD), array, j);
599 }
600 } else if (i < indexes.length) {
601 indexes[i] = argIndex;
602 }
603 }
604 assert(nameCursor == names.length-1); // leave room for the final call
605
606 // Build argument array for the call.
607 Name[] targetArgs = new Name[targetType.parameterCount()];
608 for (int i = 0; i < targetType.parameterCount(); i++) {
609 int idx = indexes[i];
610 targetArgs[i] = names[idx];
611 }
612 names[names.length - 1] = new Name(target, (Object[]) targetArgs);
613
614 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.SPREAD);
615 return SimpleMethodHandle.make(srcType, form);
616 }
617
618 static void checkSpreadArgument(Object av, int n) {
619 if (av == null && n == 0) {
620 return;
621 } else if (av == null) {
622 throw new NullPointerException("null array reference");
623 } else if (av instanceof Object[]) {
624 int len = ((Object[])av).length;
625 if (len == n) return;
626 } else {
627 int len = java.lang.reflect.Array.getLength(av);
628 if (len == n) return;
629 }
630 // fall through to error:
631 throw newIllegalArgumentException("array is not of length "+n);
632 }
633
634 /** Factory method: Collect or filter selected argument(s). */
635 static MethodHandle makeCollectArguments(MethodHandle target,
636 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
637 MethodType targetType = target.type(); // (a..., c, [b...])=>r
638 MethodType collectorType = collector.type(); // (b...)=>c
639 int collectArgCount = collectorType.parameterCount();
640 Class<?> collectValType = collectorType.returnType();
641 int collectValCount = (collectValType == void.class ? 0 : 1);
642 MethodType srcType = targetType // (a..., [b...])=>r
643 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
644 if (!retainOriginalArgs) { // (a..., b...)=>r
645 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterArray());
646 }
647 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
648 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
649 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
650
651 // Now build a LambdaForm.
652 MethodType lambdaType = srcType.invokerType();
653 Name[] names = arguments(2, lambdaType);
654 final int collectNamePos = names.length - 2;
655 final int targetNamePos = names.length - 1;
656
657 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
658 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
659
660 // Build argument array for the target.
661 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
662 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
663 Name[] targetArgs = new Name[targetType.parameterCount()];
664 int inputArgPos = 1; // incoming LF args to copy to target
665 int targetArgPos = 0; // fill pointer for targetArgs
666 int chunk = collectArgPos; // |headArgs|
667 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
668 inputArgPos += chunk;
669 targetArgPos += chunk;
670 if (collectValType != void.class) {
671 targetArgs[targetArgPos++] = names[collectNamePos];
672 }
673 chunk = collectArgCount;
674 if (retainOriginalArgs) {
675 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
676 targetArgPos += chunk; // optionally pass on the collected chunk
677 }
678 inputArgPos += chunk;
679 chunk = targetArgs.length - targetArgPos; // all the rest
680 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
681 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
682 names[targetNamePos] = new Name(target, (Object[]) targetArgs);
683
684 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.COLLECT);
685 return SimpleMethodHandle.make(srcType, form);
686 }
687
688 @Hidden
689 static MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
690 if (testResult) {
691 return target;
692 } else {
693 return fallback;
694 }
695 }
696
697 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
698 @Hidden
699 @jdk.internal.HotSpotIntrinsicCandidate
700 static boolean profileBoolean(boolean result, int[] counters) {
701 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
702 int idx = result ? 1 : 0;
703 try {
704 counters[idx] = Math.addExact(counters[idx], 1);
705 } catch (ArithmeticException e) {
706 // Avoid continuous overflow by halving the problematic count.
707 counters[idx] = counters[idx] / 2;
708 }
709 return result;
710 }
711
712 // Intrinsified by C2. Returns true if obj is a compile-time constant.
713 @Hidden
714 @jdk.internal.HotSpotIntrinsicCandidate
715 static boolean isCompileConstant(Object obj) {
716 return false;
717 }
718
719 static MethodHandle makeGuardWithTest(MethodHandle test,
720 MethodHandle target,
721 MethodHandle fallback) {
722 MethodType type = target.type();
723 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
724 MethodType basicType = type.basicType();
725 LambdaForm form = makeGuardWithTestForm(basicType);
726 BoundMethodHandle mh;
727 try {
728 if (PROFILE_GWT) {
729 int[] counts = new int[2];
730 mh = (BoundMethodHandle)
731 BoundMethodHandle.speciesData_LLLL().factory().invokeBasic(type, form,
732 (Object) test, (Object) profile(target), (Object) profile(fallback), counts);
733 } else {
734 mh = (BoundMethodHandle)
735 BoundMethodHandle.speciesData_LLL().factory().invokeBasic(type, form,
736 (Object) test, (Object) profile(target), (Object) profile(fallback));
737 }
738 } catch (Throwable ex) {
739 throw uncaughtException(ex);
740 }
741 assert(mh.type() == type);
742 return mh;
743 }
744
745
746 static MethodHandle profile(MethodHandle target) {
747 if (DONT_INLINE_THRESHOLD >= 0) {
748 return makeBlockInliningWrapper(target);
749 } else {
750 return target;
751 }
752 }
753
754 /**
755 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
756 * Corresponding LambdaForm has @DontInline when compiled into bytecode.
757 */
758 static MethodHandle makeBlockInliningWrapper(MethodHandle target) {
759 LambdaForm lform;
760 if (DONT_INLINE_THRESHOLD > 0) {
761 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target);
762 } else {
763 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target);
764 }
765 return new CountingWrapper(target, lform,
766 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM,
767 DONT_INLINE_THRESHOLD);
768 }
769
770 private final static class Makers {
771 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
772 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
773 @Override
774 public LambdaForm apply(MethodHandle target) {
775 return DelegatingMethodHandle.makeReinvokerForm(target,
776 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, false,
777 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
778 }
779 };
780
781 /** Constructs simple reinvoker lambda form for a particular method handle */
782 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
783 @Override
784 public LambdaForm apply(MethodHandle target) {
785 return DelegatingMethodHandle.makeReinvokerForm(target,
786 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
787 }
788 };
789
790 /** Maker of type-polymorphic varargs */
791 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() {
792 @Override
793 protected MethodHandle[] computeValue(Class<?> type) {
794 return new MethodHandle[MAX_JVM_ARITY + 1];
795 }
796 };
797 }
798
799 /**
800 * Counting method handle. It has 2 states: counting and non-counting.
801 * It is in counting state for the first n invocations and then transitions to non-counting state.
802 * Behavior in counting and non-counting states is determined by lambda forms produced by
803 * countingFormProducer & nonCountingFormProducer respectively.
804 */
805 static class CountingWrapper extends DelegatingMethodHandle {
806 private final MethodHandle target;
807 private int count;
808 private Function<MethodHandle, LambdaForm> countingFormProducer;
809 private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
810 private volatile boolean isCounting;
811
812 private CountingWrapper(MethodHandle target, LambdaForm lform,
813 Function<MethodHandle, LambdaForm> countingFromProducer,
814 Function<MethodHandle, LambdaForm> nonCountingFormProducer,
815 int count) {
816 super(target.type(), lform);
817 this.target = target;
818 this.count = count;
819 this.countingFormProducer = countingFromProducer;
820 this.nonCountingFormProducer = nonCountingFormProducer;
821 this.isCounting = (count > 0);
822 }
823
824 @Hidden
825 @Override
826 protected MethodHandle getTarget() {
827 return target;
828 }
829
830 @Override
831 public MethodHandle asTypeUncached(MethodType newType) {
832 MethodHandle newTarget = target.asType(newType);
833 MethodHandle wrapper;
834 if (isCounting) {
835 LambdaForm lform;
836 lform = countingFormProducer.apply(newTarget);
837 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
838 } else {
839 wrapper = newTarget; // no need for a counting wrapper anymore
840 }
841 return (asTypeCache = wrapper);
842 }
843
844 // Customize target if counting happens for too long.
845 private int invocations = CUSTOMIZE_THRESHOLD;
846 private void maybeCustomizeTarget() {
847 int c = invocations;
848 if (c >= 0) {
849 if (c == 1) {
850 target.customize();
851 }
852 invocations = c - 1;
853 }
854 }
855
856 boolean countDown() {
857 int c = count;
858 maybeCustomizeTarget();
859 if (c <= 1) {
860 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
861 if (isCounting) {
862 isCounting = false;
863 return true;
864 } else {
865 return false;
866 }
867 } else {
868 count = c - 1;
869 return false;
870 }
871 }
872
873 @Hidden
874 static void maybeStopCounting(Object o1) {
875 CountingWrapper wrapper = (CountingWrapper) o1;
876 if (wrapper.countDown()) {
877 // Reached invocation threshold. Replace counting behavior with a non-counting one.
878 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
879 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
880 wrapper.updateForm(lform);
881 }
882 }
883
884 static final NamedFunction NF_maybeStopCounting;
885 static {
886 Class<?> THIS_CLASS = CountingWrapper.class;
887 try {
888 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
889 } catch (ReflectiveOperationException ex) {
890 throw newInternalError(ex);
891 }
892 }
893 }
894
895 static LambdaForm makeGuardWithTestForm(MethodType basicType) {
896 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
897 if (lform != null) return lform;
898 final int THIS_MH = 0; // the BMH_LLL
899 final int ARG_BASE = 1; // start of incoming arguments
900 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
901 int nameCursor = ARG_LIMIT;
902 final int GET_TEST = nameCursor++;
903 final int GET_TARGET = nameCursor++;
904 final int GET_FALLBACK = nameCursor++;
905 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
906 final int CALL_TEST = nameCursor++;
907 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
908 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
909 final int SELECT_ALT = nameCursor++;
910 final int CALL_TARGET = nameCursor++;
911 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
912
913 MethodType lambdaType = basicType.invokerType();
914 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
915
916 BoundMethodHandle.SpeciesData data =
917 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
918 : BoundMethodHandle.speciesData_LLL();
919 names[THIS_MH] = names[THIS_MH].withConstraint(data);
920 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
921 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
922 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
923 if (GET_COUNTERS != -1) {
924 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
925 }
926 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
927
928 // call test
929 MethodType testType = basicType.changeReturnType(boolean.class).basicType();
930 invokeArgs[0] = names[GET_TEST];
931 names[CALL_TEST] = new Name(testType, invokeArgs);
932
933 // profile branch
934 if (PROFILE != -1) {
935 names[PROFILE] = new Name(getFunction(NF_profileBoolean), names[CALL_TEST], names[GET_COUNTERS]);
936 }
937 // call selectAlternative
938 names[SELECT_ALT] = new Name(new NamedFunction(getConstantHandle(MH_selectAlternative), Intrinsic.SELECT_ALTERNATIVE), names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
939
940 // call target or fallback
941 invokeArgs[0] = names[SELECT_ALT];
942 names[CALL_TARGET] = new Name(basicType, invokeArgs);
943
944 lform = new LambdaForm(lambdaType.parameterCount(), names, /*forceInline=*/true, Kind.GUARD);
945
946 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
947 }
948
949 /**
950 * The LambdaForm shape for catchException combinator is the following:
951 * <blockquote><pre>{@code
952 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
953 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
954 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
955 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
956 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
957 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
958 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
959 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
960 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
961 * }</pre></blockquote>
962 *
963 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
964 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
965 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
966 *
967 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
968 * among catchException combinators with the same basic type.
969 */
970 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
971 MethodType lambdaType = basicType.invokerType();
972
973 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
974 if (lform != null) {
975 return lform;
976 }
977 final int THIS_MH = 0; // the BMH_LLLLL
978 final int ARG_BASE = 1; // start of incoming arguments
979 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
980
981 int nameCursor = ARG_LIMIT;
982 final int GET_TARGET = nameCursor++;
983 final int GET_CLASS = nameCursor++;
984 final int GET_CATCHER = nameCursor++;
985 final int GET_COLLECT_ARGS = nameCursor++;
986 final int GET_UNBOX_RESULT = nameCursor++;
987 final int BOXED_ARGS = nameCursor++;
988 final int TRY_CATCH = nameCursor++;
989 final int UNBOX_RESULT = nameCursor++;
990
991 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
992
993 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
994 names[THIS_MH] = names[THIS_MH].withConstraint(data);
995 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
996 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
997 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
998 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
999 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
1000
1001 // FIXME: rework argument boxing/result unboxing logic for LF interpretation
1002
1003 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1004 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1005 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1006 Object[] args = new Object[invokeBasic.type().parameterCount()];
1007 args[0] = names[GET_COLLECT_ARGS];
1008 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
1009 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args);
1010
1011 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
1012 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
1013 names[TRY_CATCH] = new Name(getFunction(NF_guardWithCatch), gwcArgs);
1014
1015 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1016 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1017 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
1018 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1019
1020 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.GUARD_WITH_CATCH);
1021
1022 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
1023 }
1024
1025 static MethodHandle makeGuardWithCatch(MethodHandle target,
1026 Class<? extends Throwable> exType,
1027 MethodHandle catcher) {
1028 MethodType type = target.type();
1029 LambdaForm form = makeGuardWithCatchForm(type.basicType());
1030
1031 // Prepare auxiliary method handles used during LambdaForm interpretation.
1032 // Box arguments and wrap them into Object[]: ValueConversions.array().
1033 MethodType varargsType = type.changeReturnType(Object[].class);
1034 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1035 MethodHandle unboxResult = unboxResultHandle(type.returnType());
1036
1037 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
1038 BoundMethodHandle mh;
1039 try {
1040 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) exType,
1041 (Object) catcher, (Object) collectArgs, (Object) unboxResult);
1042 } catch (Throwable ex) {
1043 throw uncaughtException(ex);
1044 }
1045 assert(mh.type() == type);
1046 return mh;
1047 }
1048
1049 /**
1050 * Intrinsified during LambdaForm compilation
1051 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
1052 */
1053 @Hidden
1054 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
1055 Object... av) throws Throwable {
1056 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
1057 try {
1058 return target.asFixedArity().invokeWithArguments(av);
1059 } catch (Throwable t) {
1060 if (!exType.isInstance(t)) throw t;
1061 return catcher.asFixedArity().invokeWithArguments(prepend(av, t));
1062 }
1063 }
1064
1065 /** Prepend elements to an array. */
1066 @Hidden
1067 private static Object[] prepend(Object[] array, Object... elems) {
1068 int nArray = array.length;
1069 int nElems = elems.length;
1070 Object[] newArray = new Object[nArray + nElems];
1071 System.arraycopy(elems, 0, newArray, 0, nElems);
1072 System.arraycopy(array, 0, newArray, nElems, nArray);
1073 return newArray;
1074 }
1075
1076 static MethodHandle throwException(MethodType type) {
1077 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
1078 int arity = type.parameterCount();
1079 if (arity > 1) {
1080 MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
1081 mh = MethodHandles.dropArguments(mh, 1, Arrays.copyOfRange(type.parameterArray(), 1, arity));
1082 return mh;
1083 }
1084 return makePairwiseConvert(getFunction(NF_throwException).resolvedHandle(), type, false, true);
1085 }
1086
1087 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
1088
1089 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
1090 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
1091 int idx;
1092 assert(method.isMethodHandleInvoke());
1093 switch (method.getName()) {
1094 case "invoke": idx = 0; break;
1095 case "invokeExact": idx = 1; break;
1096 default: throw new InternalError(method.getName());
1097 }
1098 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
1099 if (mh != null) return mh;
1100 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
1101 MethodHandle.class, Object[].class);
1102 mh = throwException(type);
1103 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
1104 if (!method.getInvocationType().equals(mh.type()))
1105 throw new InternalError(method.toString());
1106 mh = mh.withInternalMemberName(method, false);
1107 mh = mh.withVarargs(true);
1108 assert(method.isVarargs());
1109 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
1110 return mh;
1111 }
1112 static MethodHandle fakeVarHandleInvoke(MemberName method) {
1113 // TODO caching, is it necessary?
1114 MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class,
1115 VarHandle.class, Object[].class);
1116 MethodHandle mh = throwException(type);
1117 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle"));
1118 if (!method.getInvocationType().equals(mh.type()))
1119 throw new InternalError(method.toString());
1120 mh = mh.withInternalMemberName(method, false);
1121 mh = mh.asVarargsCollector(Object[].class);
1122 assert(method.isVarargs());
1123 return mh;
1124 }
1125
1126 /**
1127 * Create an alias for the method handle which, when called,
1128 * appears to be called from the same class loader and protection domain
1129 * as hostClass.
1130 * This is an expensive no-op unless the method which is called
1131 * is sensitive to its caller. A small number of system methods
1132 * are in this category, including Class.forName and Method.invoke.
1133 */
1134 static MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1135 return BindCaller.bindCaller(mh, hostClass);
1136 }
1137
1138 // Put the whole mess into its own nested class.
1139 // That way we can lazily load the code and set up the constants.
1140 private static class BindCaller {
1141 private static MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1142
1143 static MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1144 // Code in the boot layer should now be careful while creating method handles or
1145 // functional interface instances created from method references to @CallerSensitive methods,
1146 // it needs to be ensured the handles or interface instances are kept safe and are not passed
1147 // from the boot layer to untrusted code.
1148 if (hostClass == null
1149 || (hostClass.isArray() ||
1150 hostClass.isPrimitive() ||
1151 hostClass.getName().startsWith("java.lang.invoke."))) {
1152 throw new InternalError(); // does not happen, and should not anyway
1153 }
1154 // For simplicity, convert mh to a varargs-like method.
1155 MethodHandle vamh = prepareForInvoker(mh);
1156 // Cache the result of makeInjectedInvoker once per argument class.
1157 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
1158 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
1159 }
1160
1161 private static MethodHandle makeInjectedInvoker(Class<?> targetClass) {
1162 try {
1163 /*
1164 * The invoker class defined to the same class loader as the lookup class
1165 * but in an unnamed package so that the class bytes can be cached and
1166 * reused for any @CSM.
1167 *
1168 * @CSM must be public and exported if called by any module.
1169 */
1170 String name = targetClass.getName() + "$$InjectedInvoker";
1171 if (targetClass.isHiddenClass()) {
1172 // use the original class name
1173 name = name.replace('/', '_');
1174 }
1175 Class<?> invokerClass = new Lookup(targetClass)
1176 .makeHiddenClassDefiner(name, INJECTED_INVOKER_TEMPLATE, 0).defineClass(true);
1177 assert checkInjectedInvoker(targetClass, invokerClass);
1178 return IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1179 } catch (ReflectiveOperationException ex) {
1180 throw uncaughtException(ex);
1181 }
1182 }
1183
1184 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
1185 @Override protected MethodHandle computeValue(Class<?> hostClass) {
1186 return makeInjectedInvoker(hostClass);
1187 }
1188 };
1189
1190 // Adapt mh so that it can be called directly from an injected invoker:
1191 private static MethodHandle prepareForInvoker(MethodHandle mh) {
1192 mh = mh.asFixedArity();
1193 MethodType mt = mh.type();
1194 int arity = mt.parameterCount();
1195 MethodHandle vamh = mh.asType(mt.generic());
1196 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1197 vamh = vamh.asSpreader(Object[].class, arity);
1198 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1199 return vamh;
1200 }
1201
1202 // Undo the adapter effect of prepareForInvoker:
1203 private static MethodHandle restoreToType(MethodHandle vamh,
1204 MethodHandle original,
1205 Class<?> hostClass) {
1206 MethodType type = original.type();
1207 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
1208 MemberName member = original.internalMemberName();
1209 mh = mh.asType(type);
1210 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
1211 return mh;
1212 }
1213
1214 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) {
1215 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)";
1216 try {
1217 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)";
1218 } catch (SecurityException ex) {
1219 // Self-check was blocked by security manager. This is OK.
1220 }
1221 try {
1222 // Test the invoker to ensure that it really injects into the right place.
1223 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1224 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
1225 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass });
1226 } catch (Throwable ex) {
1227 throw new InternalError(ex);
1228 }
1229 }
1230
1231 private static final MethodHandle MH_checkCallerClass;
1232 static {
1233 final Class<?> THIS_CLASS = BindCaller.class;
1234 assert(checkCallerClass(THIS_CLASS));
1235 try {
1236 MH_checkCallerClass = IMPL_LOOKUP
1237 .findStatic(THIS_CLASS, "checkCallerClass",
1238 MethodType.methodType(boolean.class, Class.class));
1239 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS));
1240 } catch (Throwable ex) {
1241 throw new InternalError(ex);
1242 }
1243 }
1244
1245 @CallerSensitive
1246 @ForceInline // to ensure Reflection.getCallerClass optimization
1247 private static boolean checkCallerClass(Class<?> expected) {
1248 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here.
1249 Class<?> actual = Reflection.getCallerClass();
1250 if (actual != expected)
1251 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName());
1252 return true;
1253 }
1254
1255 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate();
1256
1257 /** Produces byte code for a class that is used as an injected invoker. */
1258 private static byte[] generateInvokerTemplate() {
1259 ClassWriter cw = new ClassWriter(0);
1260
1261 // private static class InjectedInvoker {
1262 // @Hidden
1263 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
1264 // return vamh.invokeExact(args);
1265 // }
1266 // }
1267 cw.visit(52, ACC_PRIVATE | ACC_SUPER, "InjectedInvoker", null, "java/lang/Object", null);
1268
1269 MethodVisitor mv = cw.visitMethod(ACC_STATIC, "invoke_V",
1270 "(Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;",
1271 null, null);
1272
1273 mv.visitCode();
1274 mv.visitVarInsn(ALOAD, 0);
1275 mv.visitVarInsn(ALOAD, 1);
1276 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle", "invokeExact",
1277 "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1278 mv.visitInsn(ARETURN);
1279 mv.visitMaxs(2, 2);
1280 mv.visitEnd();
1281
1282 cw.visitEnd();
1283 return cw.toByteArray();
1284 }
1285 }
1286
1287 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
1288 private static final class WrappedMember extends DelegatingMethodHandle {
1289 private final MethodHandle target;
1290 private final MemberName member;
1291 private final Class<?> callerClass;
1292 private final boolean isInvokeSpecial;
1293
1294 private WrappedMember(MethodHandle target, MethodType type,
1295 MemberName member, boolean isInvokeSpecial,
1296 Class<?> callerClass) {
1297 super(type, target);
1298 this.target = target;
1299 this.member = member;
1300 this.callerClass = callerClass;
1301 this.isInvokeSpecial = isInvokeSpecial;
1302 }
1303
1304 @Override
1305 MemberName internalMemberName() {
1306 return member;
1307 }
1308 @Override
1309 Class<?> internalCallerClass() {
1310 return callerClass;
1311 }
1312 @Override
1313 boolean isInvokeSpecial() {
1314 return isInvokeSpecial;
1315 }
1316 @Override
1317 protected MethodHandle getTarget() {
1318 return target;
1319 }
1320 @Override
1321 public MethodHandle asTypeUncached(MethodType newType) {
1322 // This MH is an alias for target, except for the MemberName
1323 // Drop the MemberName if there is any conversion.
1324 return asTypeCache = target.asType(newType);
1325 }
1326 }
1327
1328 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
1329 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
1330 return target;
1331 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
1332 }
1333
1334 /** Intrinsic IDs */
1335 /*non-public*/
1336 enum Intrinsic {
1337 SELECT_ALTERNATIVE,
1338 GUARD_WITH_CATCH,
1339 TRY_FINALLY,
1340 LOOP,
1341 NEW_ARRAY,
1342 ARRAY_LOAD,
1343 ARRAY_STORE,
1344 ARRAY_LENGTH,
1345 IDENTITY,
1346 ZERO,
1347 NONE // no intrinsic associated
1348 }
1349
1350 /** Mark arbitrary method handle as intrinsic.
1351 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
1352 static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
1353 private final MethodHandle target;
1354 private final Intrinsic intrinsicName;
1355
1356 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
1357 super(target.type(), target);
1358 this.target = target;
1359 this.intrinsicName = intrinsicName;
1360 }
1361
1362 @Override
1363 protected MethodHandle getTarget() {
1364 return target;
1365 }
1366
1367 @Override
1368 Intrinsic intrinsicName() {
1369 return intrinsicName;
1370 }
1371
1372 @Override
1373 public MethodHandle asTypeUncached(MethodType newType) {
1374 // This MH is an alias for target, except for the intrinsic name
1375 // Drop the name if there is any conversion.
1376 return asTypeCache = target.asType(newType);
1377 }
1378
1379 @Override
1380 String internalProperties() {
1381 return super.internalProperties() +
1382 "\n& Intrinsic="+intrinsicName;
1383 }
1384
1385 @Override
1386 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
1387 if (intrinsicName == Intrinsic.IDENTITY) {
1388 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength);
1389 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
1390 return newArray.asType(resultType);
1391 }
1392 return super.asCollector(arrayType, arrayLength);
1393 }
1394 }
1395
1396 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
1397 if (intrinsicName == target.intrinsicName())
1398 return target;
1399 return new IntrinsicMethodHandle(target, intrinsicName);
1400 }
1401
1402 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
1403 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
1404 }
1405
1406 /// Collection of multiple arguments.
1407
1408 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) {
1409 MethodType type = MethodType.genericMethodType(nargs)
1410 .changeReturnType(rtype)
1411 .insertParameterTypes(0, ptypes);
1412 try {
1413 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type);
1414 } catch (ReflectiveOperationException ex) {
1415 return null;
1416 }
1417 }
1418
1419 private static final Object[] NO_ARGS_ARRAY = {};
1420 private static Object[] makeArray(Object... args) { return args; }
1421 private static Object[] array() { return NO_ARGS_ARRAY; }
1422 private static Object[] array(Object a0)
1423 { return makeArray(a0); }
1424 private static Object[] array(Object a0, Object a1)
1425 { return makeArray(a0, a1); }
1426 private static Object[] array(Object a0, Object a1, Object a2)
1427 { return makeArray(a0, a1, a2); }
1428 private static Object[] array(Object a0, Object a1, Object a2, Object a3)
1429 { return makeArray(a0, a1, a2, a3); }
1430 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1431 Object a4)
1432 { return makeArray(a0, a1, a2, a3, a4); }
1433 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1434 Object a4, Object a5)
1435 { return makeArray(a0, a1, a2, a3, a4, a5); }
1436 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1437 Object a4, Object a5, Object a6)
1438 { return makeArray(a0, a1, a2, a3, a4, a5, a6); }
1439 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1440 Object a4, Object a5, Object a6, Object a7)
1441 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); }
1442 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1443 Object a4, Object a5, Object a6, Object a7,
1444 Object a8)
1445 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); }
1446 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1447 Object a4, Object a5, Object a6, Object a7,
1448 Object a8, Object a9)
1449 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); }
1450
1451 private static final int ARRAYS_COUNT = 11;
1452 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1];
1453
1454 // filling versions of the above:
1455 // using Integer len instead of int len and no varargs to avoid bootstrapping problems
1456 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) {
1457 Object[] a = new Object[len];
1458 fillWithArguments(a, 0, args);
1459 return a;
1460 }
1461 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) {
1462 Object[] a = Arrays.copyOf(example, len);
1463 assert(a.getClass() != Object[].class);
1464 fillWithArguments(a, 0, args);
1465 return a;
1466 }
1467 private static void fillWithArguments(Object[] a, int pos, Object... args) {
1468 System.arraycopy(args, 0, a, pos, args.length);
1469 }
1470 // using Integer pos instead of int pos to avoid bootstrapping problems
1471 private static Object[] fillArray(Integer pos, Object[] a, Object a0)
1472 { fillWithArguments(a, pos, a0); return a; }
1473 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1)
1474 { fillWithArguments(a, pos, a0, a1); return a; }
1475 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2)
1476 { fillWithArguments(a, pos, a0, a1, a2); return a; }
1477 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3)
1478 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; }
1479 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1480 Object a4)
1481 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; }
1482 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1483 Object a4, Object a5)
1484 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; }
1485 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1486 Object a4, Object a5, Object a6)
1487 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; }
1488 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1489 Object a4, Object a5, Object a6, Object a7)
1490 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; }
1491 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1492 Object a4, Object a5, Object a6, Object a7,
1493 Object a8)
1494 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; }
1495 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1496 Object a4, Object a5, Object a6, Object a7,
1497 Object a8, Object a9)
1498 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; }
1499
1500 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods
1501 private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT];
1502
1503 private static MethodHandle getFillArray(int count) {
1504 assert (count > 0 && count < FILL_ARRAYS_COUNT);
1505 MethodHandle mh = FILL_ARRAYS[count];
1506 if (mh != null) {
1507 return mh;
1508 }
1509 mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class);
1510 FILL_ARRAYS[count] = mh;
1511 return mh;
1512 }
1513
1514 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) {
1515 Object a = w.makeArray(boxes.length);
1516 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length);
1517 return a;
1518 }
1519
1520 /** Return a method handle that takes the indicated number of Object
1521 * arguments and returns an Object array of them, as if for varargs.
1522 */
1523 static MethodHandle varargsArray(int nargs) {
1524 MethodHandle mh = ARRAYS[nargs];
1525 if (mh != null) {
1526 return mh;
1527 }
1528 if (nargs < ARRAYS_COUNT) {
1529 mh = findCollector("array", nargs, Object[].class);
1530 } else {
1531 mh = buildVarargsArray(getConstantHandle(MH_fillNewArray),
1532 getConstantHandle(MH_arrayIdentity), nargs);
1533 }
1534 assert(assertCorrectArity(mh, nargs));
1535 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1536 return ARRAYS[nargs] = mh;
1537 }
1538
1539 private static boolean assertCorrectArity(MethodHandle mh, int arity) {
1540 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
1541 return true;
1542 }
1543
1544 // Array identity function (used as getConstantHandle(MH_arrayIdentity)).
1545 static <T> T[] identity(T[] x) {
1546 return x;
1547 }
1548
1549 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) {
1550 // Build up the result mh as a sequence of fills like this:
1551 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23))
1552 // The various fill(_,10*I,___*[J]) are reusable.
1553 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately
1554 int rightLen = nargs - leftLen;
1555 MethodHandle leftCollector = newArray.bindTo(nargs);
1556 leftCollector = leftCollector.asCollector(Object[].class, leftLen);
1557 MethodHandle mh = finisher;
1558 if (rightLen > 0) {
1559 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen);
1560 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1561 mh = rightFiller;
1562 else
1563 mh = MethodHandles.collectArguments(mh, 0, rightFiller);
1564 }
1565 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1566 mh = leftCollector;
1567 else
1568 mh = MethodHandles.collectArguments(mh, 0, leftCollector);
1569 return mh;
1570 }
1571
1572 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1;
1573 private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1];
1574 /** fill_array_to_right(N).invoke(a, argL..arg[N-1])
1575 * fills a[L]..a[N-1] with corresponding arguments,
1576 * and then returns a. The value L is a global constant (LEFT_ARGS).
1577 */
1578 private static MethodHandle fillToRight(int nargs) {
1579 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs];
1580 if (filler != null) return filler;
1581 filler = buildFiller(nargs);
1582 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1));
1583 return FILL_ARRAY_TO_RIGHT[nargs] = filler;
1584 }
1585 private static MethodHandle buildFiller(int nargs) {
1586 if (nargs <= LEFT_ARGS)
1587 return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged
1588 // we need room for both mh and a in mh.invoke(a, arg*[nargs])
1589 final int CHUNK = LEFT_ARGS;
1590 int rightLen = nargs % CHUNK;
1591 int midLen = nargs - rightLen;
1592 if (rightLen == 0) {
1593 midLen = nargs - (rightLen = CHUNK);
1594 if (FILL_ARRAY_TO_RIGHT[midLen] == null) {
1595 // build some precursors from left to right
1596 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK)
1597 if (j > LEFT_ARGS) fillToRight(j);
1598 }
1599 }
1600 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS);
1601 assert(rightLen > 0);
1602 MethodHandle midFill = fillToRight(midLen); // recursive fill
1603 MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1]
1604 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS);
1605 assert(rightFill.type().parameterCount() == 1 + rightLen);
1606
1607 // Combine the two fills:
1608 // right(mid(a, x10..x19), x20..x23)
1609 // The final product will look like this:
1610 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23)
1611 if (midLen == LEFT_ARGS)
1612 return rightFill;
1613 else
1614 return MethodHandles.collectArguments(rightFill, 0, midFill);
1615 }
1616
1617 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
1618
1619 /** Return a method handle that takes the indicated number of
1620 * typed arguments and returns an array of them.
1621 * The type argument is the array type.
1622 */
1623 static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
1624 Class<?> elemType = arrayType.getComponentType();
1625 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
1626 // FIXME: Need more special casing and caching here.
1627 if (nargs >= MAX_JVM_ARITY/2 - 1) {
1628 int slots = nargs;
1629 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
1630 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
1631 slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
1632 if (slots > MAX_ARRAY_SLOTS)
1633 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
1634 }
1635 if (elemType == Object.class)
1636 return varargsArray(nargs);
1637 // other cases: primitive arrays, subtypes of Object[]
1638 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType);
1639 MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
1640 if (mh != null) return mh;
1641 if (nargs == 0) {
1642 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0);
1643 mh = MethodHandles.constant(arrayType, example);
1644 } else if (elemType.isPrimitive()) {
1645 MethodHandle builder = getConstantHandle(MH_fillNewArray);
1646 MethodHandle producer = buildArrayProducer(arrayType);
1647 mh = buildVarargsArray(builder, producer, nargs);
1648 } else {
1649 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class);
1650 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType);
1651 MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example);
1652 MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed
1653 mh = buildVarargsArray(builder, producer, nargs);
1654 }
1655 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)));
1656 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1657 assert(assertCorrectArity(mh, nargs));
1658 if (nargs < cache.length)
1659 cache[nargs] = mh;
1660 return mh;
1661 }
1662
1663 private static MethodHandle buildArrayProducer(Class<?> arrayType) {
1664 Class<?> elemType = arrayType.getComponentType();
1665 assert(elemType.isPrimitive());
1666 return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType));
1667 }
1668
1669 /*non-public*/
1670 static void assertSame(Object mh1, Object mh2) {
1671 if (mh1 != mh2) {
1672 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)",
1673 mh1, ((MethodHandle)mh1).form,
1674 mh2, ((MethodHandle)mh2).form);
1675 throw newInternalError(msg);
1676 }
1677 }
1678
1679 // Local constant functions:
1680
1681 /* non-public */
1682 static final byte NF_checkSpreadArgument = 0,
1683 NF_guardWithCatch = 1,
1684 NF_throwException = 2,
1685 NF_tryFinally = 3,
1686 NF_loop = 4,
1687 NF_profileBoolean = 5,
1688 NF_LIMIT = 6;
1689
1690 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
1691
1692 static NamedFunction getFunction(byte func) {
1693 NamedFunction nf = NFS[func];
1694 if (nf != null) {
1695 return nf;
1696 }
1697 return NFS[func] = createFunction(func);
1698 }
1699
1700 private static NamedFunction createFunction(byte func) {
1701 try {
1702 switch (func) {
1703 case NF_checkSpreadArgument:
1704 return new NamedFunction(MethodHandleImpl.class
1705 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
1706 case NF_guardWithCatch:
1707 return new NamedFunction(MethodHandleImpl.class
1708 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
1709 MethodHandle.class, Object[].class));
1710 case NF_tryFinally:
1711 return new NamedFunction(MethodHandleImpl.class
1712 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class));
1713 case NF_loop:
1714 return new NamedFunction(MethodHandleImpl.class
1715 .getDeclaredMethod("loop", BasicType[].class, LoopClauses.class, Object[].class));
1716 case NF_throwException:
1717 return new NamedFunction(MethodHandleImpl.class
1718 .getDeclaredMethod("throwException", Throwable.class));
1719 case NF_profileBoolean:
1720 return new NamedFunction(MethodHandleImpl.class
1721 .getDeclaredMethod("profileBoolean", boolean.class, int[].class));
1722 default:
1723 throw new InternalError("Undefined function: " + func);
1724 }
1725 } catch (ReflectiveOperationException ex) {
1726 throw newInternalError(ex);
1727 }
1728 }
1729
1730 static {
1731 SharedSecrets.setJavaLangInvokeAccess(new JavaLangInvokeAccess() {
1732 @Override
1733 public Object newMemberName() {
1734 return new MemberName();
1735 }
1736
1737 @Override
1738 public String getName(Object mname) {
1739 MemberName memberName = (MemberName)mname;
1740 return memberName.getName();
1741 }
1742 @Override
1743 public Class<?> getDeclaringClass(Object mname) {
1744 MemberName memberName = (MemberName)mname;
1745 return memberName.getDeclaringClass();
1746 }
1747
1748 @Override
1749 public MethodType getMethodType(Object mname) {
1750 MemberName memberName = (MemberName)mname;
1751 return memberName.getMethodType();
1752 }
1753
1754 @Override
1755 public String getMethodDescriptor(Object mname) {
1756 MemberName memberName = (MemberName)mname;
1757 return memberName.getMethodDescriptor();
1758 }
1759
1760 @Override
1761 public boolean isNative(Object mname) {
1762 MemberName memberName = (MemberName)mname;
1763 return memberName.isNative();
1764 }
1765
1766 @Override
1767 public byte[] generateDirectMethodHandleHolderClassBytes(
1768 String className, MethodType[] methodTypes, int[] types) {
1769 return GenerateJLIClassesHelper
1770 .generateDirectMethodHandleHolderClassBytes(
1771 className, methodTypes, types);
1772 }
1773
1774 @Override
1775 public byte[] generateDelegatingMethodHandleHolderClassBytes(
1776 String className, MethodType[] methodTypes) {
1777 return GenerateJLIClassesHelper
1778 .generateDelegatingMethodHandleHolderClassBytes(
1779 className, methodTypes);
1780 }
1781
1782 @Override
1783 public Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
1784 final String types) {
1785 return GenerateJLIClassesHelper
1786 .generateConcreteBMHClassBytes(types);
1787 }
1788
1789 @Override
1790 public byte[] generateBasicFormsClassBytes(final String className) {
1791 return GenerateJLIClassesHelper
1792 .generateBasicFormsClassBytes(className);
1793 }
1794
1795 @Override
1796 public byte[] generateInvokersHolderClassBytes(final String className,
1797 MethodType[] invokerMethodTypes,
1798 MethodType[] callSiteMethodTypes) {
1799 return GenerateJLIClassesHelper
1800 .generateInvokersHolderClassBytes(className,
1801 invokerMethodTypes, callSiteMethodTypes);
1802 }
1803
1804 @Override
1805 public VarHandle memoryAddressViewVarHandle(Class<?> carrier, long alignmentMask,
1806 ByteOrder order, long offset, long[] strides) {
1807 return VarHandles.makeMemoryAddressViewHandle(carrier, alignmentMask, order, offset, strides);
1808 }
1809
1810 @Override
1811 public Class<?> memoryAddressCarrier(VarHandle handle) {
1812 return checkMemAccessHandle(handle).carrier();
1813 }
1814
1815 @Override
1816 public long memoryAddressAlignmentMask(VarHandle handle) {
1817 return checkMemAccessHandle(handle).alignmentMask;
1818 }
1819
1820 @Override
1821 public ByteOrder memoryAddressByteOrder(VarHandle handle) {
1822 return checkMemAccessHandle(handle).be ?
1823 ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN;
1824 }
1825
1826 @Override
1827 public long memoryAddressOffset(VarHandle handle) {
1828 return checkMemAccessHandle(handle).offset;
1829 }
1830
1831 @Override
1832 public long[] memoryAddressStrides(VarHandle handle) {
1833 return checkMemAccessHandle(handle).strides();
1834 }
1835
1836 private VarHandleMemoryAddressBase checkMemAccessHandle(VarHandle handle) {
1837 if (!(handle instanceof VarHandleMemoryAddressBase)) {
1838 throw new IllegalArgumentException("Not a memory access varhandle: " + handle);
1839 }
1840 return (VarHandleMemoryAddressBase) handle;
1841 }
1842 });
1843 }
1844
1845 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */
1846 private static MethodHandle unboxResultHandle(Class<?> returnType) {
1847 if (returnType.isPrimitive()) {
1848 if (returnType == void.class) {
1849 return ValueConversions.ignore();
1850 } else {
1851 Wrapper w = Wrapper.forPrimitiveType(returnType);
1852 return ValueConversions.unboxExact(w);
1853 }
1854 } else {
1855 return MethodHandles.identity(Object.class);
1856 }
1857 }
1858
1859 /**
1860 * Assembles a loop method handle from the given handles and type information.
1861 *
1862 * @param tloop the return type of the loop.
1863 * @param targs types of the arguments to be passed to the loop.
1864 * @param init sanitized array of initializers for loop-local variables.
1865 * @param step sanitited array of loop bodies.
1866 * @param pred sanitized array of predicates.
1867 * @param fini sanitized array of loop finalizers.
1868 *
1869 * @return a handle that, when invoked, will execute the loop.
1870 */
1871 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step,
1872 List<MethodHandle> pred, List<MethodHandle> fini) {
1873 MethodType type = MethodType.methodType(tloop, targs);
1874 BasicType[] initClauseTypes =
1875 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new);
1876 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes);
1877
1878 // Prepare auxiliary method handles used during LambdaForm interpretation.
1879 // Box arguments and wrap them into Object[]: ValueConversions.array().
1880 MethodType varargsType = type.changeReturnType(Object[].class);
1881 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1882 MethodHandle unboxResult = unboxResultHandle(tloop);
1883
1884 LoopClauses clauseData =
1885 new LoopClauses(new MethodHandle[][]{toArray(init), toArray(step), toArray(pred), toArray(fini)});
1886 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1887 BoundMethodHandle mh;
1888 try {
1889 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) clauseData,
1890 (Object) collectArgs, (Object) unboxResult);
1891 } catch (Throwable ex) {
1892 throw uncaughtException(ex);
1893 }
1894 assert(mh.type() == type);
1895 return mh;
1896 }
1897
1898 private static MethodHandle[] toArray(List<MethodHandle> l) {
1899 return l.toArray(new MethodHandle[0]);
1900 }
1901
1902 /**
1903 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are
1904 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one
1905 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by
1906 * {@code t12}):
1907 * <blockquote><pre>{@code
1908 * loop=Lambda(a0:L,a1:L)=>{
1909 * t2:L=BoundMethodHandle$Species_L3.argL0(a0:L); // LoopClauses holding init, step, pred, fini handles
1910 * t3:L=BoundMethodHandle$Species_L3.argL1(a0:L); // helper handle to box the arguments into an Object[]
1911 * t4:L=BoundMethodHandle$Species_L3.argL2(a0:L); // helper handle to unbox the result
1912 * t5:L=MethodHandle.invokeBasic(t3:L,a1:L); // box the arguments into an Object[]
1913 * t6:L=MethodHandleImpl.loop(null,t2:L,t3:L); // call the loop executor
1914 * t7:L=MethodHandle.invokeBasic(t4:L,t6:L);t7:L} // unbox the result; return the result
1915 * }</pre></blockquote>
1916 * <p>
1917 * {@code argL0} is a LoopClauses instance holding, in a 2-dimensional array, the init, step, pred, and fini method
1918 * handles. {@code argL1} and {@code argL2} are auxiliary method handles: {@code argL1} boxes arguments and wraps
1919 * them into {@code Object[]} ({@code ValueConversions.array()}), and {@code argL2} unboxes the result if necessary
1920 * ({@code ValueConversions.unbox()}).
1921 * <p>
1922 * Having {@code t3} and {@code t4} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
1923 * forms among loop combinators with the same basic type.
1924 * <p>
1925 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to
1926 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is
1927 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int)
1928 * bytecode generation}.
1929 */
1930 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) {
1931 MethodType lambdaType = basicType.invokerType();
1932
1933 final int THIS_MH = 0; // the BMH_LLL
1934 final int ARG_BASE = 1; // start of incoming arguments
1935 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
1936
1937 int nameCursor = ARG_LIMIT;
1938 final int GET_CLAUSE_DATA = nameCursor++;
1939 final int GET_COLLECT_ARGS = nameCursor++;
1940 final int GET_UNBOX_RESULT = nameCursor++;
1941 final int BOXED_ARGS = nameCursor++;
1942 final int LOOP = nameCursor++;
1943 final int UNBOX_RESULT = nameCursor++;
1944
1945 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP);
1946 if (lform == null) {
1947 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
1948
1949 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1950 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1951 names[GET_CLAUSE_DATA] = new Name(data.getterFunction(0), names[THIS_MH]);
1952 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(1), names[THIS_MH]);
1953 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(2), names[THIS_MH]);
1954
1955 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1956 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1957 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1958 Object[] args = new Object[invokeBasic.type().parameterCount()];
1959 args[0] = names[GET_COLLECT_ARGS];
1960 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE);
1961 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.LOOP), args);
1962
1963 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,clauses:L,t_{i}:L);
1964 Object[] lArgs =
1965 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor
1966 names[GET_CLAUSE_DATA], names[BOXED_ARGS]};
1967 names[LOOP] = new Name(getFunction(NF_loop), lArgs);
1968
1969 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1970 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1971 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]};
1972 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1973
1974 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP,
1975 new LambdaForm(lambdaType.parameterCount(), names, Kind.LOOP));
1976 }
1977
1978 // BOXED_ARGS is the index into the names array where the loop idiom starts
1979 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes);
1980 }
1981
1982 static class LoopClauses {
1983 @Stable final MethodHandle[][] clauses;
1984 LoopClauses(MethodHandle[][] clauses) {
1985 assert clauses.length == 4;
1986 this.clauses = clauses;
1987 }
1988 @Override
1989 public String toString() {
1990 StringBuffer sb = new StringBuffer("LoopClauses -- ");
1991 for (int i = 0; i < 4; ++i) {
1992 if (i > 0) {
1993 sb.append(" ");
1994 }
1995 sb.append('<').append(i).append(">: ");
1996 MethodHandle[] hs = clauses[i];
1997 for (int j = 0; j < hs.length; ++j) {
1998 if (j > 0) {
1999 sb.append(" ");
2000 }
2001 sb.append('*').append(j).append(": ").append(hs[j]).append('\n');
2002 }
2003 }
2004 sb.append(" --\n");
2005 return sb.toString();
2006 }
2007 }
2008
2009 /**
2010 * Intrinsified during LambdaForm compilation
2011 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}).
2012 */
2013 @Hidden
2014 static Object loop(BasicType[] localTypes, LoopClauses clauseData, Object... av) throws Throwable {
2015 final MethodHandle[] init = clauseData.clauses[0];
2016 final MethodHandle[] step = clauseData.clauses[1];
2017 final MethodHandle[] pred = clauseData.clauses[2];
2018 final MethodHandle[] fini = clauseData.clauses[3];
2019 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count();
2020 int nArgs = init[0].type().parameterCount();
2021 Object[] varsAndArgs = new Object[varSize + nArgs];
2022 for (int i = 0, v = 0; i < init.length; ++i) {
2023 MethodHandle ih = init[i];
2024 if (ih.type().returnType() == void.class) {
2025 ih.invokeWithArguments(av);
2026 } else {
2027 varsAndArgs[v++] = ih.invokeWithArguments(av);
2028 }
2029 }
2030 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs);
2031 final int nSteps = step.length;
2032 for (; ; ) {
2033 for (int i = 0, v = 0; i < nSteps; ++i) {
2034 MethodHandle p = pred[i];
2035 MethodHandle s = step[i];
2036 MethodHandle f = fini[i];
2037 if (s.type().returnType() == void.class) {
2038 s.invokeWithArguments(varsAndArgs);
2039 } else {
2040 varsAndArgs[v++] = s.invokeWithArguments(varsAndArgs);
2041 }
2042 if (!(boolean) p.invokeWithArguments(varsAndArgs)) {
2043 return f.invokeWithArguments(varsAndArgs);
2044 }
2045 }
2046 }
2047 }
2048
2049 /**
2050 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
2051 * MethodHandle) counting loops}.
2052 *
2053 * @param limit the upper bound of the parameter, statically bound at loop creation time.
2054 * @param counter the counter parameter, passed in during loop execution.
2055 *
2056 * @return whether the counter has reached the limit.
2057 */
2058 static boolean countedLoopPredicate(int limit, int counter) {
2059 return counter < limit;
2060 }
2061
2062 /**
2063 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
2064 * MethodHandle) counting loops} to increment the counter.
2065 *
2066 * @param limit the upper bound of the loop counter (ignored).
2067 * @param counter the loop counter.
2068 *
2069 * @return the loop counter incremented by 1.
2070 */
2071 static int countedLoopStep(int limit, int counter) {
2072 return counter + 1;
2073 }
2074
2075 /**
2076 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}.
2077 *
2078 * @param it the {@link Iterable} over which the loop iterates.
2079 *
2080 * @return an {@link Iterator} over the argument's elements.
2081 */
2082 static Iterator<?> initIterator(Iterable<?> it) {
2083 return it.iterator();
2084 }
2085
2086 /**
2087 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}.
2088 *
2089 * @param it the iterator to be checked.
2090 *
2091 * @return {@code true} iff there are more elements to iterate over.
2092 */
2093 static boolean iteratePredicate(Iterator<?> it) {
2094 return it.hasNext();
2095 }
2096
2097 /**
2098 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain
2099 * MethodHandles#iteratedLoop iterating loops}.
2100 *
2101 * @param it the iterator.
2102 *
2103 * @return the next element from the iterator.
2104 */
2105 static Object iterateNext(Iterator<?> it) {
2106 return it.next();
2107 }
2108
2109 /**
2110 * Makes a {@code try-finally} handle that conforms to the type constraints.
2111 *
2112 * @param target the target to execute in a {@code try-finally} block.
2113 * @param cleanup the cleanup to execute in the {@code finally} block.
2114 * @param rtype the result type of the entire construct.
2115 * @param argTypes the types of the arguments.
2116 *
2117 * @return a handle on the constructed {@code try-finally} block.
2118 */
2119 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, List<Class<?>> argTypes) {
2120 MethodType type = MethodType.methodType(rtype, argTypes);
2121 LambdaForm form = makeTryFinallyForm(type.basicType());
2122
2123 // Prepare auxiliary method handles used during LambdaForm interpretation.
2124 // Box arguments and wrap them into Object[]: ValueConversions.array().
2125 MethodType varargsType = type.changeReturnType(Object[].class);
2126 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
2127 MethodHandle unboxResult = unboxResultHandle(rtype);
2128
2129 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2130 BoundMethodHandle mh;
2131 try {
2132 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) cleanup,
2133 (Object) collectArgs, (Object) unboxResult);
2134 } catch (Throwable ex) {
2135 throw uncaughtException(ex);
2136 }
2137 assert(mh.type() == type);
2138 return mh;
2139 }
2140
2141 /**
2142 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in
2143 * {@code a1}, and a reference return type, with the return value represented by {@code t8}):
2144 * <blockquote><pre>{@code
2145 * tryFinally=Lambda(a0:L,a1:L)=>{
2146 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle
2147 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle
2148 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[]
2149 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result
2150 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[]
2151 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor
2152 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result
2153 * }</pre></blockquote>
2154 * <p>
2155 * {@code argL0} and {@code argL1} are the target and cleanup method handles.
2156 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into
2157 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary
2158 * ({@code ValueConversions.unbox()}).
2159 * <p>
2160 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
2161 * forms among tryFinally combinators with the same basic type.
2162 */
2163 private static LambdaForm makeTryFinallyForm(MethodType basicType) {
2164 MethodType lambdaType = basicType.invokerType();
2165
2166 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF);
2167 if (lform != null) {
2168 return lform;
2169 }
2170 final int THIS_MH = 0; // the BMH_LLLL
2171 final int ARG_BASE = 1; // start of incoming arguments
2172 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
2173
2174 int nameCursor = ARG_LIMIT;
2175 final int GET_TARGET = nameCursor++;
2176 final int GET_CLEANUP = nameCursor++;
2177 final int GET_COLLECT_ARGS = nameCursor++;
2178 final int GET_UNBOX_RESULT = nameCursor++;
2179 final int BOXED_ARGS = nameCursor++;
2180 final int TRY_FINALLY = nameCursor++;
2181 final int UNBOX_RESULT = nameCursor++;
2182
2183 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
2184
2185 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2186 names[THIS_MH] = names[THIS_MH].withConstraint(data);
2187 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
2188 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]);
2189 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]);
2190 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]);
2191
2192 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
2193 MethodType collectArgsType = basicType.changeReturnType(Object.class);
2194 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
2195 Object[] args = new Object[invokeBasic.type().parameterCount()];
2196 args[0] = names[GET_COLLECT_ARGS];
2197 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
2198 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.TRY_FINALLY), args);
2199
2200 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L);
2201 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]};
2202 names[TRY_FINALLY] = new Name(getFunction(NF_tryFinally), tfArgs);
2203
2204 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
2205 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
2206 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]};
2207 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
2208
2209 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.TRY_FINALLY);
2210
2211 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform);
2212 }
2213
2214 /**
2215 * Intrinsified during LambdaForm compilation
2216 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}).
2217 */
2218 @Hidden
2219 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable {
2220 Throwable t = null;
2221 Object r = null;
2222 try {
2223 r = target.invokeWithArguments(av);
2224 } catch (Throwable thrown) {
2225 t = thrown;
2226 throw t;
2227 } finally {
2228 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r);
2229 r = cleanup.invokeWithArguments(args);
2230 }
2231 return r;
2232 }
2233
2234 // Indexes into constant method handles:
2235 static final int
2236 MH_cast = 0,
2237 MH_selectAlternative = 1,
2238 MH_copyAsPrimitiveArray = 2,
2239 MH_fillNewTypedArray = 3,
2240 MH_fillNewArray = 4,
2241 MH_arrayIdentity = 5,
2242 MH_countedLoopPred = 6,
2243 MH_countedLoopStep = 7,
2244 MH_initIterator = 8,
2245 MH_iteratePred = 9,
2246 MH_iterateNext = 10,
2247 MH_Array_newInstance = 11,
2248 MH_LIMIT = 12;
2249
2250 static MethodHandle getConstantHandle(int idx) {
2251 MethodHandle handle = HANDLES[idx];
2252 if (handle != null) {
2253 return handle;
2254 }
2255 return setCachedHandle(idx, makeConstantHandle(idx));
2256 }
2257
2258 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) {
2259 // Simulate a CAS, to avoid racy duplication of results.
2260 MethodHandle prev = HANDLES[idx];
2261 if (prev != null) {
2262 return prev;
2263 }
2264 HANDLES[idx] = method;
2265 return method;
2266 }
2267
2268 // Local constant method handles:
2269 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT];
2270
2271 private static MethodHandle makeConstantHandle(int idx) {
2272 try {
2273 switch (idx) {
2274 case MH_cast:
2275 return IMPL_LOOKUP.findVirtual(Class.class, "cast",
2276 MethodType.methodType(Object.class, Object.class));
2277 case MH_copyAsPrimitiveArray:
2278 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray",
2279 MethodType.methodType(Object.class, Wrapper.class, Object[].class));
2280 case MH_arrayIdentity:
2281 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity",
2282 MethodType.methodType(Object[].class, Object[].class));
2283 case MH_fillNewArray:
2284 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray",
2285 MethodType.methodType(Object[].class, Integer.class, Object[].class));
2286 case MH_fillNewTypedArray:
2287 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray",
2288 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class));
2289 case MH_selectAlternative:
2290 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
2291 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class));
2292 case MH_countedLoopPred:
2293 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate",
2294 MethodType.methodType(boolean.class, int.class, int.class));
2295 case MH_countedLoopStep:
2296 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep",
2297 MethodType.methodType(int.class, int.class, int.class));
2298 case MH_initIterator:
2299 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator",
2300 MethodType.methodType(Iterator.class, Iterable.class));
2301 case MH_iteratePred:
2302 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate",
2303 MethodType.methodType(boolean.class, Iterator.class));
2304 case MH_iterateNext:
2305 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext",
2306 MethodType.methodType(Object.class, Iterator.class));
2307 case MH_Array_newInstance:
2308 return IMPL_LOOKUP.findStatic(Array.class, "newInstance",
2309 MethodType.methodType(Object.class, Class.class, int.class));
2310 }
2311 } catch (ReflectiveOperationException ex) {
2312 throw newInternalError(ex);
2313 }
2314 throw newInternalError("Unknown function index: " + idx);
2315 }
2316 }