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.AnnotationVisitor;
31 import jdk.internal.org.objectweb.asm.ClassWriter;
32 import jdk.internal.org.objectweb.asm.MethodVisitor;
33 import jdk.internal.reflect.CallerSensitive;
34 import jdk.internal.reflect.Reflection;
35 import jdk.internal.vm.annotation.ForceInline;
36 import jdk.internal.vm.annotation.Hidden;
37 import jdk.internal.vm.annotation.Stable;
38 import sun.invoke.empty.Empty;
39 import sun.invoke.util.ValueConversions;
40 import sun.invoke.util.VerifyType;
41 import sun.invoke.util.Wrapper;
42
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 jdk.internal.org.objectweb.asm.Opcodes.*;
58
59 /**
60 * Trusted implementation code for MethodHandle.
61 * @author jrose
62 */
63 /*non-public*/
64 abstract class MethodHandleImpl {
65
66 /// Factory methods to create method handles:
67
68 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, ArrayAccess access) {
69 if (arrayClass == Object[].class) {
70 return ArrayAccess.objectAccessor(access);
71 }
72 if (!arrayClass.isArray())
73 throw newIllegalArgumentException("not an array: "+arrayClass);
74 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
75 int cacheIndex = ArrayAccess.cacheIndex(access);
76 MethodHandle mh = cache[cacheIndex];
77 if (mh != null) return mh;
78 mh = ArrayAccessor.getAccessor(arrayClass, access);
79 MethodType correctType = ArrayAccessor.correctType(arrayClass, access);
80 if (mh.type() != correctType) {
81 assert(mh.type().parameterType(0) == Object[].class);
82 /* if access == SET */ assert(access != ArrayAccess.SET || mh.type().parameterType(2) == Object.class);
83 /* if access == GET */ assert(access != ArrayAccess.GET ||
84 (mh.type().returnType() == Object.class &&
85 correctType.parameterType(0).getComponentType() == correctType.returnType()));
86 // safe to view non-strictly, because element type follows from array type
87 mh = mh.viewAsType(correctType, false);
88 }
89 mh = makeIntrinsic(mh, ArrayAccess.intrinsic(access));
90 // Atomically update accessor cache.
91 synchronized(cache) {
92 if (cache[cacheIndex] == null) {
93 cache[cacheIndex] = mh;
94 } else {
95 // Throw away newly constructed accessor and use cached version.
96 mh = cache[cacheIndex];
97 }
98 }
99 return mh;
100 }
101
102 enum ArrayAccess {
103 GET, SET, LENGTH;
104
105 // As ArrayAccess and ArrayAccessor have a circular dependency, the ArrayAccess properties cannot be stored in
106 // final fields.
107
108 static String opName(ArrayAccess a) {
109 switch (a) {
110 case GET: return "getElement";
111 case SET: return "setElement";
112 case LENGTH: return "length";
113 }
114 throw unmatchedArrayAccess(a);
115 }
116
117 static MethodHandle objectAccessor(ArrayAccess a) {
118 switch (a) {
119 case GET: return ArrayAccessor.OBJECT_ARRAY_GETTER;
120 case SET: return ArrayAccessor.OBJECT_ARRAY_SETTER;
121 case LENGTH: return ArrayAccessor.OBJECT_ARRAY_LENGTH;
122 }
123 throw unmatchedArrayAccess(a);
124 }
125
126 static int cacheIndex(ArrayAccess a) {
127 switch (a) {
128 case GET: return ArrayAccessor.GETTER_INDEX;
129 case SET: return ArrayAccessor.SETTER_INDEX;
130 case LENGTH: return ArrayAccessor.LENGTH_INDEX;
131 }
132 throw unmatchedArrayAccess(a);
133 }
134
135 static Intrinsic intrinsic(ArrayAccess a) {
136 switch (a) {
137 case GET: return Intrinsic.ARRAY_LOAD;
138 case SET: return Intrinsic.ARRAY_STORE;
139 case LENGTH: return Intrinsic.ARRAY_LENGTH;
140 }
141 throw unmatchedArrayAccess(a);
142 }
143 }
144
145 static InternalError unmatchedArrayAccess(ArrayAccess a) {
146 return newInternalError("should not reach here (unmatched ArrayAccess: " + a + ")");
147 }
148
149 static final class ArrayAccessor {
150 /// Support for array element and length access
151 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, LENGTH_INDEX = 2, INDEX_LIMIT = 3;
152 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
153 = new ClassValue<MethodHandle[]>() {
154 @Override
155 protected MethodHandle[] computeValue(Class<?> type) {
156 return new MethodHandle[INDEX_LIMIT];
157 }
158 };
159 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER, OBJECT_ARRAY_LENGTH;
160 static {
161 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
162 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.GET), Intrinsic.ARRAY_LOAD);
163 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.SET), Intrinsic.ARRAY_STORE);
164 cache[LENGTH_INDEX] = OBJECT_ARRAY_LENGTH = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.LENGTH), Intrinsic.ARRAY_LENGTH);
165
166 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
167 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
168 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_LENGTH.internalMemberName()));
169 }
170
171 static int getElementI(int[] a, int i) { return a[i]; }
172 static long getElementJ(long[] a, int i) { return a[i]; }
173 static float getElementF(float[] a, int i) { return a[i]; }
174 static double getElementD(double[] a, int i) { return a[i]; }
175 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
176 static byte getElementB(byte[] a, int i) { return a[i]; }
177 static short getElementS(short[] a, int i) { return a[i]; }
178 static char getElementC(char[] a, int i) { return a[i]; }
179 static Object getElementL(Object[] a, int i) { return a[i]; }
180
181 static void setElementI(int[] a, int i, int x) { a[i] = x; }
182 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
183 static void setElementF(float[] a, int i, float x) { a[i] = x; }
184 static void setElementD(double[] a, int i, double x) { a[i] = x; }
185 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
186 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
187 static void setElementS(short[] a, int i, short x) { a[i] = x; }
188 static void setElementC(char[] a, int i, char x) { a[i] = x; }
189 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
190
191 static int lengthI(int[] a) { return a.length; }
192 static int lengthJ(long[] a) { return a.length; }
193 static int lengthF(float[] a) { return a.length; }
194 static int lengthD(double[] a) { return a.length; }
195 static int lengthZ(boolean[] a) { return a.length; }
196 static int lengthB(byte[] a) { return a.length; }
197 static int lengthS(short[] a) { return a.length; }
198 static int lengthC(char[] a) { return a.length; }
199 static int lengthL(Object[] a) { return a.length; }
200
201 static String name(Class<?> arrayClass, ArrayAccess access) {
202 Class<?> elemClass = arrayClass.getComponentType();
203 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
204 return ArrayAccess.opName(access) + Wrapper.basicTypeChar(elemClass);
205 }
206 static MethodType type(Class<?> arrayClass, ArrayAccess access) {
207 Class<?> elemClass = arrayClass.getComponentType();
208 Class<?> arrayArgClass = arrayClass;
209 if (!elemClass.isPrimitive()) {
210 arrayArgClass = Object[].class;
211 elemClass = Object.class;
212 }
213 switch (access) {
214 case GET: return MethodType.methodType(elemClass, arrayArgClass, int.class);
215 case SET: return MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
216 case LENGTH: return MethodType.methodType(int.class, arrayArgClass);
217 }
218 throw unmatchedArrayAccess(access);
219 }
220 static MethodType correctType(Class<?> arrayClass, ArrayAccess access) {
221 Class<?> elemClass = arrayClass.getComponentType();
222 switch (access) {
223 case GET: return MethodType.methodType(elemClass, arrayClass, int.class);
224 case SET: return MethodType.methodType(void.class, arrayClass, int.class, elemClass);
225 case LENGTH: return MethodType.methodType(int.class, arrayClass);
226 }
227 throw unmatchedArrayAccess(access);
228 }
229 static MethodHandle getAccessor(Class<?> arrayClass, ArrayAccess access) {
230 String name = name(arrayClass, access);
231 MethodType type = type(arrayClass, access);
232 try {
233 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
234 } catch (ReflectiveOperationException ex) {
235 throw uncaughtException(ex);
236 }
237 }
238 }
239
240 /**
241 * Create a JVM-level adapter method handle to conform the given method
242 * handle to the similar newType, using only pairwise argument conversions.
243 * For each argument, convert incoming argument to the exact type needed.
244 * The argument conversions allowed are casting, boxing and unboxing,
245 * integral widening or narrowing, and floating point widening or narrowing.
246 * @param srcType required call type
247 * @param target original method handle
248 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
249 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
250 * @return an adapter to the original handle with the desired new type,
251 * or the original target if the types are already identical
252 * or null if the adaptation cannot be made
253 */
254 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
255 boolean strict, boolean monobox) {
256 MethodType dstType = target.type();
257 if (srcType == dstType)
258 return target;
259 return makePairwiseConvertByEditor(target, srcType, strict, monobox);
260 }
261
262 private static int countNonNull(Object[] array) {
263 int count = 0;
264 if (array != null) {
265 for (Object x : array) {
266 if (x != null) ++count;
267 }
268 }
269 return count;
270 }
271
272 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
273 boolean strict, boolean monobox) {
274 // In method types arguments start at index 0, while the LF
275 // editor have the MH receiver at position 0 - adjust appropriately.
276 final int MH_RECEIVER_OFFSET = 1;
277 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
278 int convCount = countNonNull(convSpecs);
279 if (convCount == 0)
280 return target.viewAsType(srcType, strict);
281 MethodType basicSrcType = srcType.basicType();
282 MethodType midType = target.type().basicType();
283 BoundMethodHandle mh = target.rebind();
284
285 // Match each unique conversion to the positions at which it is to be applied
286 var convSpecMap = new HashMap<Object, int[]>(((4 * convCount) / 3) + 1);
287 for (int i = 0; i < convSpecs.length - MH_RECEIVER_OFFSET; i++) {
288 Object convSpec = convSpecs[i];
289 if (convSpec == null) continue;
290 int[] positions = convSpecMap.get(convSpec);
291 if (positions == null) {
292 positions = new int[] { i + MH_RECEIVER_OFFSET };
293 } else {
294 positions = Arrays.copyOf(positions, positions.length + 1);
295 positions[positions.length - 1] = i + MH_RECEIVER_OFFSET;
296 }
297 convSpecMap.put(convSpec, positions);
298 }
299 for (var entry : convSpecMap.entrySet()) {
300 Object convSpec = entry.getKey();
301
302 MethodHandle fn;
303 if (convSpec instanceof Class) {
304 fn = getConstantHandle(MH_cast).bindTo(convSpec);
305 } else {
306 fn = (MethodHandle) convSpec;
307 }
308 int[] positions = entry.getValue();
309 Class<?> newType = basicSrcType.parameterType(positions[0] - MH_RECEIVER_OFFSET);
310 BasicType newBasicType = BasicType.basicType(newType);
311 convCount -= positions.length;
312 if (convCount == 0) {
313 midType = srcType;
314 } else {
315 Class<?>[] ptypes = midType.ptypes().clone();
316 for (int pos : positions) {
317 ptypes[pos - 1] = newType;
318 }
319 midType = MethodType.makeImpl(midType.rtype(), ptypes, true);
320 }
321 LambdaForm form2;
322 if (positions.length > 1) {
323 form2 = mh.editor().filterRepeatedArgumentForm(newBasicType, positions);
324 } else {
325 form2 = mh.editor().filterArgumentForm(positions[0], newBasicType);
326 }
327 mh = mh.copyWithExtendL(midType, form2, fn);
328 }
329 Object convSpec = convSpecs[convSpecs.length - 1];
330 if (convSpec != null) {
331 MethodHandle fn;
332 if (convSpec instanceof Class) {
333 if (convSpec == void.class)
334 fn = null;
335 else
336 fn = getConstantHandle(MH_cast).bindTo(convSpec);
337 } else {
338 fn = (MethodHandle) convSpec;
339 }
340 Class<?> newType = basicSrcType.returnType();
341 assert(--convCount == 0);
342 midType = srcType;
343 if (fn != null) {
344 mh = mh.rebind(); // rebind if too complex
345 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
346 mh = mh.copyWithExtendL(midType, form2, fn);
347 } else {
348 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
349 mh = mh.copyWith(midType, form2);
350 }
351 }
352 assert(convCount == 0);
353 assert(mh.type().equals(srcType));
354 return mh;
355 }
356
357 static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
358 boolean strict, boolean monobox) {
359 final int INARG_COUNT = srcType.parameterCount();
360 Object[] convSpecs = null;
361 for (int i = 0; i <= INARG_COUNT; i++) {
362 boolean isRet = (i == INARG_COUNT);
363 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
364 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
365 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
366 if (convSpecs == null) {
367 convSpecs = new Object[INARG_COUNT + 1];
368 }
369 convSpecs[i] = valueConversion(src, dst, strict, monobox);
370 }
371 }
372 return convSpecs;
373 }
374 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
375 boolean strict) {
376 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
377 }
378
379 /**
380 * Find a conversion function from the given source to the given destination.
381 * This conversion function will be used as a LF NamedFunction.
382 * Return a Class object if a simple cast is needed.
383 * Return void.class if void is involved.
384 */
385 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
386 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
387 if (dst == void.class)
388 return dst;
389 MethodHandle fn;
390 if (src.isPrimitive()) {
391 if (src == void.class) {
392 return void.class; // caller must recognize this specially
393 } else if (dst.isPrimitive()) {
394 // Examples: int->byte, byte->int, boolean->int (!strict)
395 fn = ValueConversions.convertPrimitive(src, dst);
396 } else {
397 // Examples: int->Integer, boolean->Object, float->Number
398 Wrapper wsrc = Wrapper.forPrimitiveType(src);
399 fn = ValueConversions.boxExact(wsrc);
400 assert(fn.type().parameterType(0) == wsrc.primitiveType());
401 assert(fn.type().returnType() == wsrc.wrapperType());
402 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
403 // Corner case, such as int->Long, which will probably fail.
404 MethodType mt = MethodType.methodType(dst, src);
405 if (strict)
406 fn = fn.asType(mt);
407 else
408 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
409 }
410 }
411 } else if (dst.isPrimitive()) {
412 Wrapper wdst = Wrapper.forPrimitiveType(dst);
413 if (monobox || src == wdst.wrapperType()) {
414 // Use a strongly-typed unboxer, if possible.
415 fn = ValueConversions.unboxExact(wdst, strict);
416 } else {
417 // Examples: Object->int, Number->int, Comparable->int, Byte->int
418 // must include additional conversions
419 // src must be examined at runtime, to detect Byte, Character, etc.
420 fn = (strict
421 ? ValueConversions.unboxWiden(wdst)
422 : ValueConversions.unboxCast(wdst));
423 }
424 } else {
425 // Simple reference conversion.
426 // Note: Do not check for a class hierarchy relation
427 // between src and dst. In all cases a 'null' argument
428 // will pass the cast conversion.
429 return dst;
430 }
431 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
432 return fn;
433 }
434
435 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
436 MethodType type = target.type();
437 int last = type.parameterCount() - 1;
438 if (type.parameterType(last) != arrayType)
439 target = target.asType(type.changeParameterType(last, arrayType));
440 target = target.asFixedArity(); // make sure this attribute is turned off
441 return new AsVarargsCollector(target, arrayType);
442 }
443
444 private static final class AsVarargsCollector extends DelegatingMethodHandle {
445 private final MethodHandle target;
446 private final Class<?> arrayType;
447 private @Stable MethodHandle asCollectorCache;
448
449 AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
450 this(target.type(), target, arrayType);
451 }
452 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
453 super(type, target);
454 this.target = target;
455 this.arrayType = arrayType;
456 }
457
458 @Override
459 public boolean isVarargsCollector() {
460 return true;
461 }
462
463 @Override
464 protected MethodHandle getTarget() {
465 return target;
466 }
467
468 @Override
469 public MethodHandle asFixedArity() {
470 return target;
471 }
472
473 @Override
474 MethodHandle setVarargs(MemberName member) {
475 if (member.isVarargs()) return this;
476 return asFixedArity();
477 }
478
479 @Override
480 public MethodHandle withVarargs(boolean makeVarargs) {
481 if (makeVarargs) return this;
482 return asFixedArity();
483 }
484
485 @Override
486 public MethodHandle asTypeUncached(MethodType newType) {
487 MethodType type = this.type();
488 int collectArg = type.parameterCount() - 1;
489 int newArity = newType.parameterCount();
490 if (newArity == collectArg+1 &&
491 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
492 // if arity and trailing parameter are compatible, do normal thing
493 return asTypeCache = asFixedArity().asType(newType);
494 }
495 // check cache
496 MethodHandle acc = asCollectorCache;
497 if (acc != null && acc.type().parameterCount() == newArity)
498 return asTypeCache = acc.asType(newType);
499 // build and cache a collector
500 int arrayLength = newArity - collectArg;
501 MethodHandle collector;
502 try {
503 collector = asFixedArity().asCollector(arrayType, arrayLength);
504 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
505 } catch (IllegalArgumentException ex) {
506 throw new WrongMethodTypeException("cannot build collector", ex);
507 }
508 asCollectorCache = collector;
509 return asTypeCache = collector.asType(newType);
510 }
511
512 @Override
513 boolean viewAsTypeChecks(MethodType newType, boolean strict) {
514 super.viewAsTypeChecks(newType, true);
515 if (strict) return true;
516 // extra assertion for non-strict checks:
517 assert (type().lastParameterType().getComponentType()
518 .isAssignableFrom(
519 newType.lastParameterType().getComponentType()))
520 : Arrays.asList(this, newType);
521 return true;
522 }
523
524 @Override
525 public Object invokeWithArguments(Object... arguments) throws Throwable {
526 MethodType type = this.type();
527 int argc;
528 final int MAX_SAFE = 127; // 127 longs require 254 slots, which is safe to spread
529 if (arguments == null
530 || (argc = arguments.length) <= MAX_SAFE
531 || argc < type.parameterCount()) {
532 return super.invokeWithArguments(arguments);
533 }
534
535 // a jumbo invocation requires more explicit reboxing of the trailing arguments
536 int uncollected = type.parameterCount() - 1;
537 Class<?> elemType = arrayType.getComponentType();
538 int collected = argc - uncollected;
539 Object collArgs = (elemType == Object.class)
540 ? new Object[collected] : Array.newInstance(elemType, collected);
541 if (!elemType.isPrimitive()) {
542 // simple cast: just do some casting
543 try {
544 System.arraycopy(arguments, uncollected, collArgs, 0, collected);
545 } catch (ArrayStoreException ex) {
546 return super.invokeWithArguments(arguments);
547 }
548 } else {
549 // corner case of flat array requires reflection (or specialized copy loop)
550 MethodHandle arraySetter = MethodHandles.arrayElementSetter(arrayType);
551 try {
552 for (int i = 0; i < collected; i++) {
553 arraySetter.invoke(collArgs, i, arguments[uncollected + i]);
554 }
555 } catch (WrongMethodTypeException|ClassCastException ex) {
556 return super.invokeWithArguments(arguments);
557 }
558 }
559
560 // chop the jumbo list down to size and call in non-varargs mode
561 Object[] newArgs = new Object[uncollected + 1];
562 System.arraycopy(arguments, 0, newArgs, 0, uncollected);
563 newArgs[uncollected] = collArgs;
564 return asFixedArity().invokeWithArguments(newArgs);
565 }
566 }
567
568 /** Factory method: Spread selected argument. */
569 static MethodHandle makeSpreadArguments(MethodHandle target,
570 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
571 MethodType targetType = target.type();
572
573 for (int i = 0; i < spreadArgCount; i++) {
574 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
575 if (arg == null) arg = Object.class;
576 targetType = targetType.changeParameterType(spreadArgPos + i, arg);
577 }
578 target = target.asType(targetType);
579
580 MethodType srcType = targetType
581 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
582 // Now build a LambdaForm.
583 MethodType lambdaType = srcType.invokerType();
584 Name[] names = arguments(spreadArgCount + 2, lambdaType);
585 int nameCursor = lambdaType.parameterCount();
586 int[] indexes = new int[targetType.parameterCount()];
587
588 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
589 Class<?> src = lambdaType.parameterType(i);
590 if (i == spreadArgPos) {
591 // Spread the array.
592 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
593 Name array = names[argIndex];
594 names[nameCursor++] = new Name(getFunction(NF_checkSpreadArgument), array, spreadArgCount);
595 for (int j = 0; j < spreadArgCount; i++, j++) {
596 indexes[i] = nameCursor;
597 names[nameCursor++] = new Name(new NamedFunction(aload, Intrinsic.ARRAY_LOAD), array, j);
598 }
599 } else if (i < indexes.length) {
600 indexes[i] = argIndex;
601 }
602 }
603 assert(nameCursor == names.length-1); // leave room for the final call
604
605 // Build argument array for the call.
606 Name[] targetArgs = new Name[targetType.parameterCount()];
607 for (int i = 0; i < targetType.parameterCount(); i++) {
608 int idx = indexes[i];
609 targetArgs[i] = names[idx];
610 }
611 names[names.length - 1] = new Name(target, (Object[]) targetArgs);
612
613 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.SPREAD);
614 return SimpleMethodHandle.make(srcType, form);
615 }
616
617 static void checkSpreadArgument(Object av, int n) {
618 if (av == null && n == 0) {
619 return;
620 } else if (av == null) {
621 throw new NullPointerException("null array reference");
622 } else if (av instanceof Object[]) {
623 int len = ((Object[])av).length;
624 if (len == n) return;
625 } else {
626 int len = java.lang.reflect.Array.getLength(av);
627 if (len == n) return;
628 }
629 // fall through to error:
630 throw newIllegalArgumentException("array is not of length "+n);
631 }
632
633 /** Factory method: Collect or filter selected argument(s). */
634 static MethodHandle makeCollectArguments(MethodHandle target,
635 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
636 MethodType targetType = target.type(); // (a..., c, [b...])=>r
637 MethodType collectorType = collector.type(); // (b...)=>c
638 int collectArgCount = collectorType.parameterCount();
639 Class<?> collectValType = collectorType.returnType();
640 int collectValCount = (collectValType == void.class ? 0 : 1);
641 MethodType srcType = targetType // (a..., [b...])=>r
642 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
643 if (!retainOriginalArgs) { // (a..., b...)=>r
644 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterArray());
645 }
646 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
647 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
648 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
649
650 // Now build a LambdaForm.
651 MethodType lambdaType = srcType.invokerType();
652 Name[] names = arguments(2, lambdaType);
653 final int collectNamePos = names.length - 2;
654 final int targetNamePos = names.length - 1;
655
656 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
657 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
658
659 // Build argument array for the target.
660 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
661 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
662 Name[] targetArgs = new Name[targetType.parameterCount()];
663 int inputArgPos = 1; // incoming LF args to copy to target
664 int targetArgPos = 0; // fill pointer for targetArgs
665 int chunk = collectArgPos; // |headArgs|
666 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
667 inputArgPos += chunk;
668 targetArgPos += chunk;
669 if (collectValType != void.class) {
670 targetArgs[targetArgPos++] = names[collectNamePos];
671 }
672 chunk = collectArgCount;
673 if (retainOriginalArgs) {
674 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
675 targetArgPos += chunk; // optionally pass on the collected chunk
676 }
677 inputArgPos += chunk;
678 chunk = targetArgs.length - targetArgPos; // all the rest
679 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
680 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
681 names[targetNamePos] = new Name(target, (Object[]) targetArgs);
682
683 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.COLLECT);
684 return SimpleMethodHandle.make(srcType, form);
685 }
686
687 @Hidden
688 static MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
689 if (testResult) {
690 return target;
691 } else {
692 return fallback;
693 }
694 }
695
696 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
697 @Hidden
698 @jdk.internal.HotSpotIntrinsicCandidate
699 static boolean profileBoolean(boolean result, int[] counters) {
700 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
701 int idx = result ? 1 : 0;
702 try {
703 counters[idx] = Math.addExact(counters[idx], 1);
704 } catch (ArithmeticException e) {
705 // Avoid continuous overflow by halving the problematic count.
706 counters[idx] = counters[idx] / 2;
707 }
708 return result;
709 }
710
711 // Intrinsified by C2. Returns true if obj is a compile-time constant.
712 @Hidden
713 @jdk.internal.HotSpotIntrinsicCandidate
714 static boolean isCompileConstant(Object obj) {
715 return false;
716 }
717
718 static MethodHandle makeGuardWithTest(MethodHandle test,
719 MethodHandle target,
720 MethodHandle fallback) {
721 MethodType type = target.type();
722 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
723 MethodType basicType = type.basicType();
724 LambdaForm form = makeGuardWithTestForm(basicType);
725 BoundMethodHandle mh;
726 try {
727 if (PROFILE_GWT) {
728 int[] counts = new int[2];
729 mh = (BoundMethodHandle)
730 BoundMethodHandle.speciesData_LLLL().factory().invokeBasic(type, form,
731 (Object) test, (Object) profile(target), (Object) profile(fallback), counts);
732 } else {
733 mh = (BoundMethodHandle)
734 BoundMethodHandle.speciesData_LLL().factory().invokeBasic(type, form,
735 (Object) test, (Object) profile(target), (Object) profile(fallback));
736 }
737 } catch (Throwable ex) {
738 throw uncaughtException(ex);
739 }
740 assert(mh.type() == type);
741 return mh;
742 }
743
744
745 static MethodHandle profile(MethodHandle target) {
746 if (DONT_INLINE_THRESHOLD >= 0) {
747 return makeBlockInliningWrapper(target);
748 } else {
749 return target;
750 }
751 }
752
753 /**
754 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
755 * Corresponding LambdaForm has @DontInline when compiled into bytecode.
756 */
757 static MethodHandle makeBlockInliningWrapper(MethodHandle target) {
758 LambdaForm lform;
759 if (DONT_INLINE_THRESHOLD > 0) {
760 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target);
761 } else {
762 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target);
763 }
764 return new CountingWrapper(target, lform,
765 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM,
766 DONT_INLINE_THRESHOLD);
767 }
768
769 private final static class Makers {
770 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
771 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
772 @Override
773 public LambdaForm apply(MethodHandle target) {
774 return DelegatingMethodHandle.makeReinvokerForm(target,
775 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, false,
776 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
777 }
778 };
779
780 /** Constructs simple reinvoker lambda form for a particular method handle */
781 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
782 @Override
783 public LambdaForm apply(MethodHandle target) {
784 return DelegatingMethodHandle.makeReinvokerForm(target,
785 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
786 }
787 };
788
789 /** Maker of type-polymorphic varargs */
790 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() {
791 @Override
792 protected MethodHandle[] computeValue(Class<?> type) {
793 return new MethodHandle[MAX_JVM_ARITY + 1];
794 }
795 };
796 }
797
798 /**
799 * Counting method handle. It has 2 states: counting and non-counting.
800 * It is in counting state for the first n invocations and then transitions to non-counting state.
801 * Behavior in counting and non-counting states is determined by lambda forms produced by
802 * countingFormProducer & nonCountingFormProducer respectively.
803 */
804 static class CountingWrapper extends DelegatingMethodHandle {
805 private final MethodHandle target;
806 private int count;
807 private Function<MethodHandle, LambdaForm> countingFormProducer;
808 private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
809 private volatile boolean isCounting;
810
811 private CountingWrapper(MethodHandle target, LambdaForm lform,
812 Function<MethodHandle, LambdaForm> countingFromProducer,
813 Function<MethodHandle, LambdaForm> nonCountingFormProducer,
814 int count) {
815 super(target.type(), lform);
816 this.target = target;
817 this.count = count;
818 this.countingFormProducer = countingFromProducer;
819 this.nonCountingFormProducer = nonCountingFormProducer;
820 this.isCounting = (count > 0);
821 }
822
823 @Hidden
824 @Override
825 protected MethodHandle getTarget() {
826 return target;
827 }
828
829 @Override
830 public MethodHandle asTypeUncached(MethodType newType) {
831 MethodHandle newTarget = target.asType(newType);
832 MethodHandle wrapper;
833 if (isCounting) {
834 LambdaForm lform;
835 lform = countingFormProducer.apply(newTarget);
836 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
837 } else {
838 wrapper = newTarget; // no need for a counting wrapper anymore
839 }
840 return (asTypeCache = wrapper);
841 }
842
843 // Customize target if counting happens for too long.
844 private int invocations = CUSTOMIZE_THRESHOLD;
845 private void maybeCustomizeTarget() {
846 int c = invocations;
847 if (c >= 0) {
848 if (c == 1) {
849 target.customize();
850 }
851 invocations = c - 1;
852 }
853 }
854
855 boolean countDown() {
856 int c = count;
857 maybeCustomizeTarget();
858 if (c <= 1) {
859 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
860 if (isCounting) {
861 isCounting = false;
862 return true;
863 } else {
864 return false;
865 }
866 } else {
867 count = c - 1;
868 return false;
869 }
870 }
871
872 @Hidden
873 static void maybeStopCounting(Object o1) {
874 CountingWrapper wrapper = (CountingWrapper) o1;
875 if (wrapper.countDown()) {
876 // Reached invocation threshold. Replace counting behavior with a non-counting one.
877 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
878 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
879 wrapper.updateForm(lform);
880 }
881 }
882
883 static final NamedFunction NF_maybeStopCounting;
884 static {
885 Class<?> THIS_CLASS = CountingWrapper.class;
886 try {
887 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
888 } catch (ReflectiveOperationException ex) {
889 throw newInternalError(ex);
890 }
891 }
892 }
893
894 static LambdaForm makeGuardWithTestForm(MethodType basicType) {
895 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
896 if (lform != null) return lform;
897 final int THIS_MH = 0; // the BMH_LLL
898 final int ARG_BASE = 1; // start of incoming arguments
899 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
900 int nameCursor = ARG_LIMIT;
901 final int GET_TEST = nameCursor++;
902 final int GET_TARGET = nameCursor++;
903 final int GET_FALLBACK = nameCursor++;
904 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
905 final int CALL_TEST = nameCursor++;
906 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
907 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
908 final int SELECT_ALT = nameCursor++;
909 final int CALL_TARGET = nameCursor++;
910 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
911
912 MethodType lambdaType = basicType.invokerType();
913 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
914
915 BoundMethodHandle.SpeciesData data =
916 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
917 : BoundMethodHandle.speciesData_LLL();
918 names[THIS_MH] = names[THIS_MH].withConstraint(data);
919 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
920 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
921 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
922 if (GET_COUNTERS != -1) {
923 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
924 }
925 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
926
927 // call test
928 MethodType testType = basicType.changeReturnType(boolean.class).basicType();
929 invokeArgs[0] = names[GET_TEST];
930 names[CALL_TEST] = new Name(testType, invokeArgs);
931
932 // profile branch
933 if (PROFILE != -1) {
934 names[PROFILE] = new Name(getFunction(NF_profileBoolean), names[CALL_TEST], names[GET_COUNTERS]);
935 }
936 // call selectAlternative
937 names[SELECT_ALT] = new Name(new NamedFunction(getConstantHandle(MH_selectAlternative), Intrinsic.SELECT_ALTERNATIVE), names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
938
939 // call target or fallback
940 invokeArgs[0] = names[SELECT_ALT];
941 names[CALL_TARGET] = new Name(basicType, invokeArgs);
942
943 lform = new LambdaForm(lambdaType.parameterCount(), names, /*forceInline=*/true, Kind.GUARD);
944
945 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
946 }
947
948 /**
949 * The LambdaForm shape for catchException combinator is the following:
950 * <blockquote><pre>{@code
951 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
952 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
953 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
954 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
955 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
956 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
957 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
958 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
959 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
960 * }</pre></blockquote>
961 *
962 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
963 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
964 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
965 *
966 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
967 * among catchException combinators with the same basic type.
968 */
969 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
970 MethodType lambdaType = basicType.invokerType();
971
972 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
973 if (lform != null) {
974 return lform;
975 }
976 final int THIS_MH = 0; // the BMH_LLLLL
977 final int ARG_BASE = 1; // start of incoming arguments
978 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
979
980 int nameCursor = ARG_LIMIT;
981 final int GET_TARGET = nameCursor++;
982 final int GET_CLASS = nameCursor++;
983 final int GET_CATCHER = nameCursor++;
984 final int GET_COLLECT_ARGS = nameCursor++;
985 final int GET_UNBOX_RESULT = nameCursor++;
986 final int BOXED_ARGS = nameCursor++;
987 final int TRY_CATCH = nameCursor++;
988 final int UNBOX_RESULT = nameCursor++;
989
990 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
991
992 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
993 names[THIS_MH] = names[THIS_MH].withConstraint(data);
994 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
995 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
996 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
997 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
998 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
999
1000 // FIXME: rework argument boxing/result unboxing logic for LF interpretation
1001
1002 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1003 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1004 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1005 Object[] args = new Object[invokeBasic.type().parameterCount()];
1006 args[0] = names[GET_COLLECT_ARGS];
1007 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
1008 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args);
1009
1010 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
1011 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
1012 names[TRY_CATCH] = new Name(getFunction(NF_guardWithCatch), gwcArgs);
1013
1014 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1015 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1016 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
1017 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1018
1019 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.GUARD_WITH_CATCH);
1020
1021 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
1022 }
1023
1024 static MethodHandle makeGuardWithCatch(MethodHandle target,
1025 Class<? extends Throwable> exType,
1026 MethodHandle catcher) {
1027 MethodType type = target.type();
1028 LambdaForm form = makeGuardWithCatchForm(type.basicType());
1029
1030 // Prepare auxiliary method handles used during LambdaForm interpretation.
1031 // Box arguments and wrap them into Object[]: ValueConversions.array().
1032 MethodType varargsType = type.changeReturnType(Object[].class);
1033 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1034 MethodHandle unboxResult = unboxResultHandle(type.returnType());
1035
1036 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
1037 BoundMethodHandle mh;
1038 try {
1039 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) exType,
1040 (Object) catcher, (Object) collectArgs, (Object) unboxResult);
1041 } catch (Throwable ex) {
1042 throw uncaughtException(ex);
1043 }
1044 assert(mh.type() == type);
1045 return mh;
1046 }
1047
1048 /**
1049 * Intrinsified during LambdaForm compilation
1050 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
1051 */
1052 @Hidden
1053 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
1054 Object... av) throws Throwable {
1055 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
1056 try {
1057 return target.asFixedArity().invokeWithArguments(av);
1058 } catch (Throwable t) {
1059 if (!exType.isInstance(t)) throw t;
1060 return catcher.asFixedArity().invokeWithArguments(prepend(av, t));
1061 }
1062 }
1063
1064 /** Prepend elements to an array. */
1065 @Hidden
1066 private static Object[] prepend(Object[] array, Object... elems) {
1067 int nArray = array.length;
1068 int nElems = elems.length;
1069 Object[] newArray = new Object[nArray + nElems];
1070 System.arraycopy(elems, 0, newArray, 0, nElems);
1071 System.arraycopy(array, 0, newArray, nElems, nArray);
1072 return newArray;
1073 }
1074
1075 static MethodHandle throwException(MethodType type) {
1076 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
1077 int arity = type.parameterCount();
1078 if (arity > 1) {
1079 MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
1080 mh = MethodHandles.dropArguments(mh, 1, Arrays.copyOfRange(type.parameterArray(), 1, arity));
1081 return mh;
1082 }
1083 return makePairwiseConvert(getFunction(NF_throwException).resolvedHandle(), type, false, true);
1084 }
1085
1086 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
1087
1088 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
1089 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
1090 int idx;
1091 assert(method.isMethodHandleInvoke());
1092 switch (method.getName()) {
1093 case "invoke": idx = 0; break;
1094 case "invokeExact": idx = 1; break;
1095 default: throw new InternalError(method.getName());
1096 }
1097 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
1098 if (mh != null) return mh;
1099 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
1100 MethodHandle.class, Object[].class);
1101 mh = throwException(type);
1102 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
1103 if (!method.getInvocationType().equals(mh.type()))
1104 throw new InternalError(method.toString());
1105 mh = mh.withInternalMemberName(method, false);
1106 mh = mh.withVarargs(true);
1107 assert(method.isVarargs());
1108 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
1109 return mh;
1110 }
1111 static MethodHandle fakeVarHandleInvoke(MemberName method) {
1112 // TODO caching, is it necessary?
1113 MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class,
1114 VarHandle.class, Object[].class);
1115 MethodHandle mh = throwException(type);
1116 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle"));
1117 if (!method.getInvocationType().equals(mh.type()))
1118 throw new InternalError(method.toString());
1119 mh = mh.withInternalMemberName(method, false);
1120 mh = mh.asVarargsCollector(Object[].class);
1121 assert(method.isVarargs());
1122 return mh;
1123 }
1124
1125 /**
1126 * Create an alias for the method handle which, when called,
1127 * appears to be called from the same class loader and protection domain
1128 * as hostClass.
1129 * This is an expensive no-op unless the method which is called
1130 * is sensitive to its caller. A small number of system methods
1131 * are in this category, including Class.forName and Method.invoke.
1132 */
1133 static MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1134 return BindCaller.bindCaller(mh, hostClass);
1135 }
1136
1137 // Put the whole mess into its own nested class.
1138 // That way we can lazily load the code and set up the constants.
1139 private static class BindCaller {
1140 private static MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1141
1142 static MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1143 // Code in the boot layer should now be careful while creating method handles or
1144 // functional interface instances created from method references to @CallerSensitive methods,
1145 // it needs to be ensured the handles or interface instances are kept safe and are not passed
1146 // from the boot layer to untrusted code.
1147 if (hostClass == null
1148 || (hostClass.isArray() ||
1149 hostClass.isPrimitive() ||
1150 hostClass.getName().startsWith("java.lang.invoke."))) {
1151 throw new InternalError(); // does not happen, and should not anyway
1152 }
1153 // For simplicity, convert mh to a varargs-like method.
1154 MethodHandle vamh = prepareForInvoker(mh);
1155 // Cache the result of makeInjectedInvoker once per argument class.
1156 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
1157 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
1158 }
1159
1160 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) {
1161 try {
1162 Class<?> invokerClass = UNSAFE.defineAnonymousClass(hostClass, INJECTED_INVOKER_TEMPLATE, null);
1163 assert checkInjectedInvoker(hostClass, invokerClass);
1164 return IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1165 } catch (ReflectiveOperationException ex) {
1166 throw uncaughtException(ex);
1167 }
1168 }
1169
1170 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
1171 @Override protected MethodHandle computeValue(Class<?> hostClass) {
1172 return makeInjectedInvoker(hostClass);
1173 }
1174 };
1175
1176 // Adapt mh so that it can be called directly from an injected invoker:
1177 private static MethodHandle prepareForInvoker(MethodHandle mh) {
1178 mh = mh.asFixedArity();
1179 MethodType mt = mh.type();
1180 int arity = mt.parameterCount();
1181 MethodHandle vamh = mh.asType(mt.generic());
1182 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1183 vamh = vamh.asSpreader(Object[].class, arity);
1184 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1185 return vamh;
1186 }
1187
1188 // Undo the adapter effect of prepareForInvoker:
1189 private static MethodHandle restoreToType(MethodHandle vamh,
1190 MethodHandle original,
1191 Class<?> hostClass) {
1192 MethodType type = original.type();
1193 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
1194 MemberName member = original.internalMemberName();
1195 mh = mh.asType(type);
1196 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
1197 return mh;
1198 }
1199
1200 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) {
1201 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)";
1202 try {
1203 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)";
1204 } catch (SecurityException ex) {
1205 // Self-check was blocked by security manager. This is OK.
1206 }
1207 try {
1208 // Test the invoker to ensure that it really injects into the right place.
1209 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1210 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
1211 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass });
1212 } catch (Throwable ex) {
1213 throw new InternalError(ex);
1214 }
1215 }
1216
1217 private static final MethodHandle MH_checkCallerClass;
1218 static {
1219 final Class<?> THIS_CLASS = BindCaller.class;
1220 assert(checkCallerClass(THIS_CLASS));
1221 try {
1222 MH_checkCallerClass = IMPL_LOOKUP
1223 .findStatic(THIS_CLASS, "checkCallerClass",
1224 MethodType.methodType(boolean.class, Class.class));
1225 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS));
1226 } catch (Throwable ex) {
1227 throw new InternalError(ex);
1228 }
1229 }
1230
1231 @CallerSensitive
1232 @ForceInline // to ensure Reflection.getCallerClass optimization
1233 private static boolean checkCallerClass(Class<?> expected) {
1234 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here.
1235 Class<?> actual = Reflection.getCallerClass();
1236 if (actual != expected)
1237 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName());
1238 return true;
1239 }
1240
1241 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate();
1242
1243 /** Produces byte code for a class that is used as an injected invoker. */
1244 private static byte[] generateInvokerTemplate() {
1245 ClassWriter cw = new ClassWriter(0);
1246
1247 // private static class InjectedInvoker {
1248 // @Hidden
1249 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
1250 // return vamh.invokeExact(args);
1251 // }
1252 // }
1253 cw.visit(52, ACC_PRIVATE | ACC_SUPER, "InjectedInvoker", null, "java/lang/Object", null);
1254
1255 MethodVisitor mv = cw.visitMethod(ACC_STATIC, "invoke_V",
1256 "(Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;",
1257 null, null);
1258
1259 // Suppress invoker method in stack traces.
1260 AnnotationVisitor av0 = mv.visitAnnotation(InvokerBytecodeGenerator.HIDDEN_SIG, true);
1261 av0.visitEnd();
1262
1263 mv.visitCode();
1264 mv.visitVarInsn(ALOAD, 0);
1265 mv.visitVarInsn(ALOAD, 1);
1266 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle", "invokeExact",
1267 "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1268 mv.visitInsn(ARETURN);
1269 mv.visitMaxs(2, 2);
1270 mv.visitEnd();
1271
1272 cw.visitEnd();
1273 return cw.toByteArray();
1274 }
1275 }
1276
1277 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
1278 private static final class WrappedMember extends DelegatingMethodHandle {
1279 private final MethodHandle target;
1280 private final MemberName member;
1281 private final Class<?> callerClass;
1282 private final boolean isInvokeSpecial;
1283
1284 private WrappedMember(MethodHandle target, MethodType type,
1285 MemberName member, boolean isInvokeSpecial,
1286 Class<?> callerClass) {
1287 super(type, target);
1288 this.target = target;
1289 this.member = member;
1290 this.callerClass = callerClass;
1291 this.isInvokeSpecial = isInvokeSpecial;
1292 }
1293
1294 @Override
1295 MemberName internalMemberName() {
1296 return member;
1297 }
1298 @Override
1299 Class<?> internalCallerClass() {
1300 return callerClass;
1301 }
1302 @Override
1303 boolean isInvokeSpecial() {
1304 return isInvokeSpecial;
1305 }
1306 @Override
1307 protected MethodHandle getTarget() {
1308 return target;
1309 }
1310 @Override
1311 public MethodHandle asTypeUncached(MethodType newType) {
1312 // This MH is an alias for target, except for the MemberName
1313 // Drop the MemberName if there is any conversion.
1314 return asTypeCache = target.asType(newType);
1315 }
1316 }
1317
1318 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
1319 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
1320 return target;
1321 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
1322 }
1323
1324 /** Intrinsic IDs */
1325 /*non-public*/
1326 enum Intrinsic {
1327 SELECT_ALTERNATIVE,
1328 GUARD_WITH_CATCH,
1329 TRY_FINALLY,
1330 LOOP,
1331 NEW_ARRAY,
1332 ARRAY_LOAD,
1333 ARRAY_STORE,
1334 ARRAY_LENGTH,
1335 IDENTITY,
1336 ZERO,
1337 NONE // no intrinsic associated
1338 }
1339
1340 /** Mark arbitrary method handle as intrinsic.
1341 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
1342 static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
1343 private final MethodHandle target;
1344 private final Intrinsic intrinsicName;
1345
1346 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
1347 super(target.type(), target);
1348 this.target = target;
1349 this.intrinsicName = intrinsicName;
1350 }
1351
1352 @Override
1353 protected MethodHandle getTarget() {
1354 return target;
1355 }
1356
1357 @Override
1358 Intrinsic intrinsicName() {
1359 return intrinsicName;
1360 }
1361
1362 @Override
1363 public MethodHandle asTypeUncached(MethodType newType) {
1364 // This MH is an alias for target, except for the intrinsic name
1365 // Drop the name if there is any conversion.
1366 return asTypeCache = target.asType(newType);
1367 }
1368
1369 @Override
1370 String internalProperties() {
1371 return super.internalProperties() +
1372 "\n& Intrinsic="+intrinsicName;
1373 }
1374
1375 @Override
1376 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
1377 if (intrinsicName == Intrinsic.IDENTITY) {
1378 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength);
1379 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
1380 return newArray.asType(resultType);
1381 }
1382 return super.asCollector(arrayType, arrayLength);
1383 }
1384 }
1385
1386 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
1387 if (intrinsicName == target.intrinsicName())
1388 return target;
1389 return new IntrinsicMethodHandle(target, intrinsicName);
1390 }
1391
1392 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
1393 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
1394 }
1395
1396 /// Collection of multiple arguments.
1397
1398 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) {
1399 MethodType type = MethodType.genericMethodType(nargs)
1400 .changeReturnType(rtype)
1401 .insertParameterTypes(0, ptypes);
1402 try {
1403 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type);
1404 } catch (ReflectiveOperationException ex) {
1405 return null;
1406 }
1407 }
1408
1409 private static final Object[] NO_ARGS_ARRAY = {};
1410 private static Object[] makeArray(Object... args) { return args; }
1411 private static Object[] array() { return NO_ARGS_ARRAY; }
1412 private static Object[] array(Object a0)
1413 { return makeArray(a0); }
1414 private static Object[] array(Object a0, Object a1)
1415 { return makeArray(a0, a1); }
1416 private static Object[] array(Object a0, Object a1, Object a2)
1417 { return makeArray(a0, a1, a2); }
1418 private static Object[] array(Object a0, Object a1, Object a2, Object a3)
1419 { return makeArray(a0, a1, a2, a3); }
1420 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1421 Object a4)
1422 { return makeArray(a0, a1, a2, a3, a4); }
1423 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1424 Object a4, Object a5)
1425 { return makeArray(a0, a1, a2, a3, a4, a5); }
1426 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1427 Object a4, Object a5, Object a6)
1428 { return makeArray(a0, a1, a2, a3, a4, a5, a6); }
1429 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1430 Object a4, Object a5, Object a6, Object a7)
1431 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); }
1432 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1433 Object a4, Object a5, Object a6, Object a7,
1434 Object a8)
1435 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); }
1436 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1437 Object a4, Object a5, Object a6, Object a7,
1438 Object a8, Object a9)
1439 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); }
1440
1441 private static final int ARRAYS_COUNT = 11;
1442 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1];
1443
1444 // filling versions of the above:
1445 // using Integer len instead of int len and no varargs to avoid bootstrapping problems
1446 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) {
1447 Object[] a = new Object[len];
1448 fillWithArguments(a, 0, args);
1449 return a;
1450 }
1451 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) {
1452 Object[] a = Arrays.copyOf(example, len);
1453 assert(a.getClass() != Object[].class);
1454 fillWithArguments(a, 0, args);
1455 return a;
1456 }
1457 private static void fillWithArguments(Object[] a, int pos, Object... args) {
1458 System.arraycopy(args, 0, a, pos, args.length);
1459 }
1460 // using Integer pos instead of int pos to avoid bootstrapping problems
1461 private static Object[] fillArray(Integer pos, Object[] a, Object a0)
1462 { fillWithArguments(a, pos, a0); return a; }
1463 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1)
1464 { fillWithArguments(a, pos, a0, a1); return a; }
1465 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2)
1466 { fillWithArguments(a, pos, a0, a1, a2); return a; }
1467 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3)
1468 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; }
1469 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1470 Object a4)
1471 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; }
1472 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1473 Object a4, Object a5)
1474 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; }
1475 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1476 Object a4, Object a5, Object a6)
1477 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; }
1478 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1479 Object a4, Object a5, Object a6, Object a7)
1480 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; }
1481 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1482 Object a4, Object a5, Object a6, Object a7,
1483 Object a8)
1484 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); 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, Object a7,
1487 Object a8, Object a9)
1488 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; }
1489
1490 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods
1491 private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT];
1492
1493 private static MethodHandle getFillArray(int count) {
1494 assert (count > 0 && count < FILL_ARRAYS_COUNT);
1495 MethodHandle mh = FILL_ARRAYS[count];
1496 if (mh != null) {
1497 return mh;
1498 }
1499 mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class);
1500 FILL_ARRAYS[count] = mh;
1501 return mh;
1502 }
1503
1504 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) {
1505 Object a = w.makeArray(boxes.length);
1506 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length);
1507 return a;
1508 }
1509
1510 /** Return a method handle that takes the indicated number of Object
1511 * arguments and returns an Object array of them, as if for varargs.
1512 */
1513 static MethodHandle varargsArray(int nargs) {
1514 MethodHandle mh = ARRAYS[nargs];
1515 if (mh != null) {
1516 return mh;
1517 }
1518 if (nargs < ARRAYS_COUNT) {
1519 mh = findCollector("array", nargs, Object[].class);
1520 } else {
1521 mh = buildVarargsArray(getConstantHandle(MH_fillNewArray),
1522 getConstantHandle(MH_arrayIdentity), nargs);
1523 }
1524 assert(assertCorrectArity(mh, nargs));
1525 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1526 return ARRAYS[nargs] = mh;
1527 }
1528
1529 private static boolean assertCorrectArity(MethodHandle mh, int arity) {
1530 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
1531 return true;
1532 }
1533
1534 // Array identity function (used as getConstantHandle(MH_arrayIdentity)).
1535 static <T> T[] identity(T[] x) {
1536 return x;
1537 }
1538
1539 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) {
1540 // Build up the result mh as a sequence of fills like this:
1541 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23))
1542 // The various fill(_,10*I,___*[J]) are reusable.
1543 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately
1544 int rightLen = nargs - leftLen;
1545 MethodHandle leftCollector = newArray.bindTo(nargs);
1546 leftCollector = leftCollector.asCollector(Object[].class, leftLen);
1547 MethodHandle mh = finisher;
1548 if (rightLen > 0) {
1549 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen);
1550 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1551 mh = rightFiller;
1552 else
1553 mh = MethodHandles.collectArguments(mh, 0, rightFiller);
1554 }
1555 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1556 mh = leftCollector;
1557 else
1558 mh = MethodHandles.collectArguments(mh, 0, leftCollector);
1559 return mh;
1560 }
1561
1562 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1;
1563 private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1];
1564 /** fill_array_to_right(N).invoke(a, argL..arg[N-1])
1565 * fills a[L]..a[N-1] with corresponding arguments,
1566 * and then returns a. The value L is a global constant (LEFT_ARGS).
1567 */
1568 private static MethodHandle fillToRight(int nargs) {
1569 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs];
1570 if (filler != null) return filler;
1571 filler = buildFiller(nargs);
1572 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1));
1573 return FILL_ARRAY_TO_RIGHT[nargs] = filler;
1574 }
1575 private static MethodHandle buildFiller(int nargs) {
1576 if (nargs <= LEFT_ARGS)
1577 return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged
1578 // we need room for both mh and a in mh.invoke(a, arg*[nargs])
1579 final int CHUNK = LEFT_ARGS;
1580 int rightLen = nargs % CHUNK;
1581 int midLen = nargs - rightLen;
1582 if (rightLen == 0) {
1583 midLen = nargs - (rightLen = CHUNK);
1584 if (FILL_ARRAY_TO_RIGHT[midLen] == null) {
1585 // build some precursors from left to right
1586 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK)
1587 if (j > LEFT_ARGS) fillToRight(j);
1588 }
1589 }
1590 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS);
1591 assert(rightLen > 0);
1592 MethodHandle midFill = fillToRight(midLen); // recursive fill
1593 MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1]
1594 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS);
1595 assert(rightFill.type().parameterCount() == 1 + rightLen);
1596
1597 // Combine the two fills:
1598 // right(mid(a, x10..x19), x20..x23)
1599 // The final product will look like this:
1600 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23)
1601 if (midLen == LEFT_ARGS)
1602 return rightFill;
1603 else
1604 return MethodHandles.collectArguments(rightFill, 0, midFill);
1605 }
1606
1607 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
1608
1609 /** Return a method handle that takes the indicated number of
1610 * typed arguments and returns an array of them.
1611 * The type argument is the array type.
1612 */
1613 static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
1614 Class<?> elemType = arrayType.getComponentType();
1615 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
1616 // FIXME: Need more special casing and caching here.
1617 if (nargs >= MAX_JVM_ARITY/2 - 1) {
1618 int slots = nargs;
1619 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
1620 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
1621 slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
1622 if (slots > MAX_ARRAY_SLOTS)
1623 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
1624 }
1625 if (elemType == Object.class)
1626 return varargsArray(nargs);
1627 // other cases: primitive arrays, subtypes of Object[]
1628 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType);
1629 MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
1630 if (mh != null) return mh;
1631 if (nargs == 0) {
1632 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0);
1633 mh = MethodHandles.constant(arrayType, example);
1634 } else if (elemType.isPrimitive()) {
1635 MethodHandle builder = getConstantHandle(MH_fillNewArray);
1636 MethodHandle producer = buildArrayProducer(arrayType);
1637 mh = buildVarargsArray(builder, producer, nargs);
1638 } else {
1639 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class);
1640 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType);
1641 MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example);
1642 MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed
1643 mh = buildVarargsArray(builder, producer, nargs);
1644 }
1645 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)));
1646 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1647 assert(assertCorrectArity(mh, nargs));
1648 if (nargs < cache.length)
1649 cache[nargs] = mh;
1650 return mh;
1651 }
1652
1653 private static MethodHandle buildArrayProducer(Class<?> arrayType) {
1654 Class<?> elemType = arrayType.getComponentType();
1655 assert(elemType.isPrimitive());
1656 return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType));
1657 }
1658
1659 /*non-public*/
1660 static void assertSame(Object mh1, Object mh2) {
1661 if (mh1 != mh2) {
1662 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)",
1663 mh1, ((MethodHandle)mh1).form,
1664 mh2, ((MethodHandle)mh2).form);
1665 throw newInternalError(msg);
1666 }
1667 }
1668
1669 // Local constant functions:
1670
1671 /* non-public */
1672 static final byte NF_checkSpreadArgument = 0,
1673 NF_guardWithCatch = 1,
1674 NF_throwException = 2,
1675 NF_tryFinally = 3,
1676 NF_loop = 4,
1677 NF_profileBoolean = 5,
1678 NF_LIMIT = 6;
1679
1680 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
1681
1682 static NamedFunction getFunction(byte func) {
1683 NamedFunction nf = NFS[func];
1684 if (nf != null) {
1685 return nf;
1686 }
1687 return NFS[func] = createFunction(func);
1688 }
1689
1690 private static NamedFunction createFunction(byte func) {
1691 try {
1692 switch (func) {
1693 case NF_checkSpreadArgument:
1694 return new NamedFunction(MethodHandleImpl.class
1695 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
1696 case NF_guardWithCatch:
1697 return new NamedFunction(MethodHandleImpl.class
1698 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
1699 MethodHandle.class, Object[].class));
1700 case NF_tryFinally:
1701 return new NamedFunction(MethodHandleImpl.class
1702 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class));
1703 case NF_loop:
1704 return new NamedFunction(MethodHandleImpl.class
1705 .getDeclaredMethod("loop", BasicType[].class, LoopClauses.class, Object[].class));
1706 case NF_throwException:
1707 return new NamedFunction(MethodHandleImpl.class
1708 .getDeclaredMethod("throwException", Throwable.class));
1709 case NF_profileBoolean:
1710 return new NamedFunction(MethodHandleImpl.class
1711 .getDeclaredMethod("profileBoolean", boolean.class, int[].class));
1712 default:
1713 throw new InternalError("Undefined function: " + func);
1714 }
1715 } catch (ReflectiveOperationException ex) {
1716 throw newInternalError(ex);
1717 }
1718 }
1719
1720 static {
1721 SharedSecrets.setJavaLangInvokeAccess(new JavaLangInvokeAccess() {
1722 @Override
1723 public Object newMemberName() {
1724 return new MemberName();
1725 }
1726
1727 @Override
1728 public String getName(Object mname) {
1729 MemberName memberName = (MemberName)mname;
1730 return memberName.getName();
1731 }
1732 @Override
1733 public Class<?> getDeclaringClass(Object mname) {
1734 MemberName memberName = (MemberName)mname;
1735 return memberName.getDeclaringClass();
1736 }
1737
1738 @Override
1739 public MethodType getMethodType(Object mname) {
1740 MemberName memberName = (MemberName)mname;
1741 return memberName.getMethodType();
1742 }
1743
1744 @Override
1745 public String getMethodDescriptor(Object mname) {
1746 MemberName memberName = (MemberName)mname;
1747 return memberName.getMethodDescriptor();
1748 }
1749
1750 @Override
1751 public boolean isNative(Object mname) {
1752 MemberName memberName = (MemberName)mname;
1753 return memberName.isNative();
1754 }
1755
1756 @Override
1757 public byte[] generateDirectMethodHandleHolderClassBytes(
1758 String className, MethodType[] methodTypes, int[] types) {
1759 return GenerateJLIClassesHelper
1760 .generateDirectMethodHandleHolderClassBytes(
1761 className, methodTypes, types);
1762 }
1763
1764 @Override
1765 public byte[] generateDelegatingMethodHandleHolderClassBytes(
1766 String className, MethodType[] methodTypes) {
1767 return GenerateJLIClassesHelper
1768 .generateDelegatingMethodHandleHolderClassBytes(
1769 className, methodTypes);
1770 }
1771
1772 @Override
1773 public Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
1774 final String types) {
1775 return GenerateJLIClassesHelper
1776 .generateConcreteBMHClassBytes(types);
1777 }
1778
1779 @Override
1780 public byte[] generateBasicFormsClassBytes(final String className) {
1781 return GenerateJLIClassesHelper
1782 .generateBasicFormsClassBytes(className);
1783 }
1784
1785 @Override
1786 public byte[] generateInvokersHolderClassBytes(final String className,
1787 MethodType[] invokerMethodTypes,
1788 MethodType[] callSiteMethodTypes) {
1789 return GenerateJLIClassesHelper
1790 .generateInvokersHolderClassBytes(className,
1791 invokerMethodTypes, callSiteMethodTypes);
1792 }
1793
1794 @Override
1795 public VarHandle memoryAddressViewVarHandle(Class<?> carrier, long alignmentMask,
1796 ByteOrder order, long offset, long[] strides) {
1797 return VarHandles.makeMemoryAddressViewHandle(carrier, alignmentMask, order, offset, strides);
1798 }
1799
1800 @Override
1801 public Class<?> memoryAddressCarrier(VarHandle handle) {
1802 return checkMemAccessHandle(handle).carrier();
1803 }
1804
1805 @Override
1806 public long memoryAddressAlignmentMask(VarHandle handle) {
1807 return checkMemAccessHandle(handle).alignmentMask;
1808 }
1809
1810 @Override
1811 public ByteOrder memoryAddressByteOrder(VarHandle handle) {
1812 return checkMemAccessHandle(handle).be ?
1813 ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN;
1814 }
1815
1816 @Override
1817 public long memoryAddressOffset(VarHandle handle) {
1818 return checkMemAccessHandle(handle).offset;
1819 }
1820
1821 @Override
1822 public long[] memoryAddressStrides(VarHandle handle) {
1823 return checkMemAccessHandle(handle).strides();
1824 }
1825
1826 private VarHandleMemoryAddressBase checkMemAccessHandle(VarHandle handle) {
1827 if (!(handle instanceof VarHandleMemoryAddressBase)) {
1828 throw new IllegalArgumentException("Not a memory access varhandle: " + handle);
1829 }
1830 return (VarHandleMemoryAddressBase) handle;
1831 }
1832 });
1833 }
1834
1835 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */
1836 private static MethodHandle unboxResultHandle(Class<?> returnType) {
1837 if (returnType.isPrimitive()) {
1838 if (returnType == void.class) {
1839 return ValueConversions.ignore();
1840 } else {
1841 Wrapper w = Wrapper.forPrimitiveType(returnType);
1842 return ValueConversions.unboxExact(w);
1843 }
1844 } else {
1845 return MethodHandles.identity(Object.class);
1846 }
1847 }
1848
1849 /**
1850 * Assembles a loop method handle from the given handles and type information.
1851 *
1852 * @param tloop the return type of the loop.
1853 * @param targs types of the arguments to be passed to the loop.
1854 * @param init sanitized array of initializers for loop-local variables.
1855 * @param step sanitited array of loop bodies.
1856 * @param pred sanitized array of predicates.
1857 * @param fini sanitized array of loop finalizers.
1858 *
1859 * @return a handle that, when invoked, will execute the loop.
1860 */
1861 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step,
1862 List<MethodHandle> pred, List<MethodHandle> fini) {
1863 MethodType type = MethodType.methodType(tloop, targs);
1864 BasicType[] initClauseTypes =
1865 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new);
1866 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes);
1867
1868 // Prepare auxiliary method handles used during LambdaForm interpretation.
1869 // Box arguments and wrap them into Object[]: ValueConversions.array().
1870 MethodType varargsType = type.changeReturnType(Object[].class);
1871 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1872 MethodHandle unboxResult = unboxResultHandle(tloop);
1873
1874 LoopClauses clauseData =
1875 new LoopClauses(new MethodHandle[][]{toArray(init), toArray(step), toArray(pred), toArray(fini)});
1876 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1877 BoundMethodHandle mh;
1878 try {
1879 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) clauseData,
1880 (Object) collectArgs, (Object) unboxResult);
1881 } catch (Throwable ex) {
1882 throw uncaughtException(ex);
1883 }
1884 assert(mh.type() == type);
1885 return mh;
1886 }
1887
1888 private static MethodHandle[] toArray(List<MethodHandle> l) {
1889 return l.toArray(new MethodHandle[0]);
1890 }
1891
1892 /**
1893 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are
1894 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one
1895 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by
1896 * {@code t12}):
1897 * <blockquote><pre>{@code
1898 * loop=Lambda(a0:L,a1:L)=>{
1899 * t2:L=BoundMethodHandle$Species_L3.argL0(a0:L); // LoopClauses holding init, step, pred, fini handles
1900 * t3:L=BoundMethodHandle$Species_L3.argL1(a0:L); // helper handle to box the arguments into an Object[]
1901 * t4:L=BoundMethodHandle$Species_L3.argL2(a0:L); // helper handle to unbox the result
1902 * t5:L=MethodHandle.invokeBasic(t3:L,a1:L); // box the arguments into an Object[]
1903 * t6:L=MethodHandleImpl.loop(null,t2:L,t3:L); // call the loop executor
1904 * t7:L=MethodHandle.invokeBasic(t4:L,t6:L);t7:L} // unbox the result; return the result
1905 * }</pre></blockquote>
1906 * <p>
1907 * {@code argL0} is a LoopClauses instance holding, in a 2-dimensional array, the init, step, pred, and fini method
1908 * handles. {@code argL1} and {@code argL2} are auxiliary method handles: {@code argL1} boxes arguments and wraps
1909 * them into {@code Object[]} ({@code ValueConversions.array()}), and {@code argL2} unboxes the result if necessary
1910 * ({@code ValueConversions.unbox()}).
1911 * <p>
1912 * Having {@code t3} and {@code t4} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
1913 * forms among loop combinators with the same basic type.
1914 * <p>
1915 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to
1916 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is
1917 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int)
1918 * bytecode generation}.
1919 */
1920 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) {
1921 MethodType lambdaType = basicType.invokerType();
1922
1923 final int THIS_MH = 0; // the BMH_LLL
1924 final int ARG_BASE = 1; // start of incoming arguments
1925 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
1926
1927 int nameCursor = ARG_LIMIT;
1928 final int GET_CLAUSE_DATA = nameCursor++;
1929 final int GET_COLLECT_ARGS = nameCursor++;
1930 final int GET_UNBOX_RESULT = nameCursor++;
1931 final int BOXED_ARGS = nameCursor++;
1932 final int LOOP = nameCursor++;
1933 final int UNBOX_RESULT = nameCursor++;
1934
1935 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP);
1936 if (lform == null) {
1937 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
1938
1939 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1940 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1941 names[GET_CLAUSE_DATA] = new Name(data.getterFunction(0), names[THIS_MH]);
1942 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(1), names[THIS_MH]);
1943 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(2), names[THIS_MH]);
1944
1945 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1946 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1947 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1948 Object[] args = new Object[invokeBasic.type().parameterCount()];
1949 args[0] = names[GET_COLLECT_ARGS];
1950 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE);
1951 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.LOOP), args);
1952
1953 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,clauses:L,t_{i}:L);
1954 Object[] lArgs =
1955 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor
1956 names[GET_CLAUSE_DATA], names[BOXED_ARGS]};
1957 names[LOOP] = new Name(getFunction(NF_loop), lArgs);
1958
1959 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1960 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1961 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]};
1962 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1963
1964 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP,
1965 new LambdaForm(lambdaType.parameterCount(), names, Kind.LOOP));
1966 }
1967
1968 // BOXED_ARGS is the index into the names array where the loop idiom starts
1969 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes);
1970 }
1971
1972 static class LoopClauses {
1973 @Stable final MethodHandle[][] clauses;
1974 LoopClauses(MethodHandle[][] clauses) {
1975 assert clauses.length == 4;
1976 this.clauses = clauses;
1977 }
1978 @Override
1979 public String toString() {
1980 StringBuffer sb = new StringBuffer("LoopClauses -- ");
1981 for (int i = 0; i < 4; ++i) {
1982 if (i > 0) {
1983 sb.append(" ");
1984 }
1985 sb.append('<').append(i).append(">: ");
1986 MethodHandle[] hs = clauses[i];
1987 for (int j = 0; j < hs.length; ++j) {
1988 if (j > 0) {
1989 sb.append(" ");
1990 }
1991 sb.append('*').append(j).append(": ").append(hs[j]).append('\n');
1992 }
1993 }
1994 sb.append(" --\n");
1995 return sb.toString();
1996 }
1997 }
1998
1999 /**
2000 * Intrinsified during LambdaForm compilation
2001 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}).
2002 */
2003 @Hidden
2004 static Object loop(BasicType[] localTypes, LoopClauses clauseData, Object... av) throws Throwable {
2005 final MethodHandle[] init = clauseData.clauses[0];
2006 final MethodHandle[] step = clauseData.clauses[1];
2007 final MethodHandle[] pred = clauseData.clauses[2];
2008 final MethodHandle[] fini = clauseData.clauses[3];
2009 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count();
2010 int nArgs = init[0].type().parameterCount();
2011 Object[] varsAndArgs = new Object[varSize + nArgs];
2012 for (int i = 0, v = 0; i < init.length; ++i) {
2013 MethodHandle ih = init[i];
2014 if (ih.type().returnType() == void.class) {
2015 ih.invokeWithArguments(av);
2016 } else {
2017 varsAndArgs[v++] = ih.invokeWithArguments(av);
2018 }
2019 }
2020 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs);
2021 final int nSteps = step.length;
2022 for (; ; ) {
2023 for (int i = 0, v = 0; i < nSteps; ++i) {
2024 MethodHandle p = pred[i];
2025 MethodHandle s = step[i];
2026 MethodHandle f = fini[i];
2027 if (s.type().returnType() == void.class) {
2028 s.invokeWithArguments(varsAndArgs);
2029 } else {
2030 varsAndArgs[v++] = s.invokeWithArguments(varsAndArgs);
2031 }
2032 if (!(boolean) p.invokeWithArguments(varsAndArgs)) {
2033 return f.invokeWithArguments(varsAndArgs);
2034 }
2035 }
2036 }
2037 }
2038
2039 /**
2040 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
2041 * MethodHandle) counting loops}.
2042 *
2043 * @param limit the upper bound of the parameter, statically bound at loop creation time.
2044 * @param counter the counter parameter, passed in during loop execution.
2045 *
2046 * @return whether the counter has reached the limit.
2047 */
2048 static boolean countedLoopPredicate(int limit, int counter) {
2049 return counter < limit;
2050 }
2051
2052 /**
2053 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
2054 * MethodHandle) counting loops} to increment the counter.
2055 *
2056 * @param limit the upper bound of the loop counter (ignored).
2057 * @param counter the loop counter.
2058 *
2059 * @return the loop counter incremented by 1.
2060 */
2061 static int countedLoopStep(int limit, int counter) {
2062 return counter + 1;
2063 }
2064
2065 /**
2066 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}.
2067 *
2068 * @param it the {@link Iterable} over which the loop iterates.
2069 *
2070 * @return an {@link Iterator} over the argument's elements.
2071 */
2072 static Iterator<?> initIterator(Iterable<?> it) {
2073 return it.iterator();
2074 }
2075
2076 /**
2077 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}.
2078 *
2079 * @param it the iterator to be checked.
2080 *
2081 * @return {@code true} iff there are more elements to iterate over.
2082 */
2083 static boolean iteratePredicate(Iterator<?> it) {
2084 return it.hasNext();
2085 }
2086
2087 /**
2088 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain
2089 * MethodHandles#iteratedLoop iterating loops}.
2090 *
2091 * @param it the iterator.
2092 *
2093 * @return the next element from the iterator.
2094 */
2095 static Object iterateNext(Iterator<?> it) {
2096 return it.next();
2097 }
2098
2099 /**
2100 * Makes a {@code try-finally} handle that conforms to the type constraints.
2101 *
2102 * @param target the target to execute in a {@code try-finally} block.
2103 * @param cleanup the cleanup to execute in the {@code finally} block.
2104 * @param rtype the result type of the entire construct.
2105 * @param argTypes the types of the arguments.
2106 *
2107 * @return a handle on the constructed {@code try-finally} block.
2108 */
2109 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, List<Class<?>> argTypes) {
2110 MethodType type = MethodType.methodType(rtype, argTypes);
2111 LambdaForm form = makeTryFinallyForm(type.basicType());
2112
2113 // Prepare auxiliary method handles used during LambdaForm interpretation.
2114 // Box arguments and wrap them into Object[]: ValueConversions.array().
2115 MethodType varargsType = type.changeReturnType(Object[].class);
2116 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
2117 MethodHandle unboxResult = unboxResultHandle(rtype);
2118
2119 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2120 BoundMethodHandle mh;
2121 try {
2122 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) cleanup,
2123 (Object) collectArgs, (Object) unboxResult);
2124 } catch (Throwable ex) {
2125 throw uncaughtException(ex);
2126 }
2127 assert(mh.type() == type);
2128 return mh;
2129 }
2130
2131 /**
2132 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in
2133 * {@code a1}, and a reference return type, with the return value represented by {@code t8}):
2134 * <blockquote><pre>{@code
2135 * tryFinally=Lambda(a0:L,a1:L)=>{
2136 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle
2137 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle
2138 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[]
2139 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result
2140 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[]
2141 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor
2142 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result
2143 * }</pre></blockquote>
2144 * <p>
2145 * {@code argL0} and {@code argL1} are the target and cleanup method handles.
2146 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into
2147 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary
2148 * ({@code ValueConversions.unbox()}).
2149 * <p>
2150 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
2151 * forms among tryFinally combinators with the same basic type.
2152 */
2153 private static LambdaForm makeTryFinallyForm(MethodType basicType) {
2154 MethodType lambdaType = basicType.invokerType();
2155
2156 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF);
2157 if (lform != null) {
2158 return lform;
2159 }
2160 final int THIS_MH = 0; // the BMH_LLLL
2161 final int ARG_BASE = 1; // start of incoming arguments
2162 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
2163
2164 int nameCursor = ARG_LIMIT;
2165 final int GET_TARGET = nameCursor++;
2166 final int GET_CLEANUP = nameCursor++;
2167 final int GET_COLLECT_ARGS = nameCursor++;
2168 final int GET_UNBOX_RESULT = nameCursor++;
2169 final int BOXED_ARGS = nameCursor++;
2170 final int TRY_FINALLY = nameCursor++;
2171 final int UNBOX_RESULT = nameCursor++;
2172
2173 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
2174
2175 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2176 names[THIS_MH] = names[THIS_MH].withConstraint(data);
2177 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
2178 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]);
2179 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]);
2180 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]);
2181
2182 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
2183 MethodType collectArgsType = basicType.changeReturnType(Object.class);
2184 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
2185 Object[] args = new Object[invokeBasic.type().parameterCount()];
2186 args[0] = names[GET_COLLECT_ARGS];
2187 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
2188 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.TRY_FINALLY), args);
2189
2190 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L);
2191 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]};
2192 names[TRY_FINALLY] = new Name(getFunction(NF_tryFinally), tfArgs);
2193
2194 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
2195 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
2196 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]};
2197 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
2198
2199 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.TRY_FINALLY);
2200
2201 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform);
2202 }
2203
2204 /**
2205 * Intrinsified during LambdaForm compilation
2206 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}).
2207 */
2208 @Hidden
2209 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable {
2210 Throwable t = null;
2211 Object r = null;
2212 try {
2213 r = target.invokeWithArguments(av);
2214 } catch (Throwable thrown) {
2215 t = thrown;
2216 throw t;
2217 } finally {
2218 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r);
2219 r = cleanup.invokeWithArguments(args);
2220 }
2221 return r;
2222 }
2223
2224 // Indexes into constant method handles:
2225 static final int
2226 MH_cast = 0,
2227 MH_selectAlternative = 1,
2228 MH_copyAsPrimitiveArray = 2,
2229 MH_fillNewTypedArray = 3,
2230 MH_fillNewArray = 4,
2231 MH_arrayIdentity = 5,
2232 MH_countedLoopPred = 6,
2233 MH_countedLoopStep = 7,
2234 MH_initIterator = 8,
2235 MH_iteratePred = 9,
2236 MH_iterateNext = 10,
2237 MH_Array_newInstance = 11,
2238 MH_LIMIT = 12;
2239
2240 static MethodHandle getConstantHandle(int idx) {
2241 MethodHandle handle = HANDLES[idx];
2242 if (handle != null) {
2243 return handle;
2244 }
2245 return setCachedHandle(idx, makeConstantHandle(idx));
2246 }
2247
2248 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) {
2249 // Simulate a CAS, to avoid racy duplication of results.
2250 MethodHandle prev = HANDLES[idx];
2251 if (prev != null) {
2252 return prev;
2253 }
2254 HANDLES[idx] = method;
2255 return method;
2256 }
2257
2258 // Local constant method handles:
2259 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT];
2260
2261 private static MethodHandle makeConstantHandle(int idx) {
2262 try {
2263 switch (idx) {
2264 case MH_cast:
2265 return IMPL_LOOKUP.findVirtual(Class.class, "cast",
2266 MethodType.methodType(Object.class, Object.class));
2267 case MH_copyAsPrimitiveArray:
2268 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray",
2269 MethodType.methodType(Object.class, Wrapper.class, Object[].class));
2270 case MH_arrayIdentity:
2271 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity",
2272 MethodType.methodType(Object[].class, Object[].class));
2273 case MH_fillNewArray:
2274 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray",
2275 MethodType.methodType(Object[].class, Integer.class, Object[].class));
2276 case MH_fillNewTypedArray:
2277 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray",
2278 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class));
2279 case MH_selectAlternative:
2280 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
2281 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class));
2282 case MH_countedLoopPred:
2283 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate",
2284 MethodType.methodType(boolean.class, int.class, int.class));
2285 case MH_countedLoopStep:
2286 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep",
2287 MethodType.methodType(int.class, int.class, int.class));
2288 case MH_initIterator:
2289 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator",
2290 MethodType.methodType(Iterator.class, Iterable.class));
2291 case MH_iteratePred:
2292 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate",
2293 MethodType.methodType(boolean.class, Iterator.class));
2294 case MH_iterateNext:
2295 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext",
2296 MethodType.methodType(Object.class, Iterator.class));
2297 case MH_Array_newInstance:
2298 return IMPL_LOOKUP.findStatic(Array.class, "newInstance",
2299 MethodType.methodType(Object.class, Class.class, int.class));
2300 }
2301 } catch (ReflectiveOperationException ex) {
2302 throw newInternalError(ex);
2303 }
2304 throw newInternalError("Unknown function index: " + idx);
2305 }
2306 }